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linux_dsm_epyc7002/drivers/gpu/drm/drm_dp_mst_topology.c
Wayne Lin 64e62bdf04 drm/dp_mst: Remove VCPI while disabling topology mgr 
[Why]

This patch is trying to address the issue observed when hotplug DP
daisy chain monitors.

e.g.
src-mstb-mstb-sst -> src (unplug) mstb-mstb-sst -> src-mstb-mstb-sst
(plug in again)

Once unplug a DP MST capable device, driver will call
drm_dp_mst_topology_mgr_set_mst() to disable MST. In this function,
it cleans data of topology manager while disabling mst_state. However,
it doesn't clean up the proposed_vcpis of topology manager.
If proposed_vcpi is not reset, once plug in MST daisy chain monitors
later, code will fail at checking port validation while trying to
allocate payloads.

When MST capable device is plugged in again and try to allocate
payloads by calling drm_dp_update_payload_part1(), this
function will iterate over all proposed virtual channels to see if
any proposed VCPI's num_slots is greater than 0. If any proposed
VCPI's num_slots is greater than 0 and the port which the
specific virtual channel directed to is not in the topology, code then
fails at the port validation. Since there are stale VCPI allocations
from the previous topology enablement in proposed_vcpi[], code will fail
at port validation and reurn EINVAL.

[How]

Clean up the data of stale proposed_vcpi[] and reset mgr->proposed_vcpis
to NULL while disabling mst in drm_dp_mst_topology_mgr_set_mst().

Changes since v1:
*Add on more details in commit message to describe the issue which the
patch is trying to fix

Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
[added cc to stable]
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191205090043.7580-1-Wayne.Lin@amd.com
Cc: <stable@vger.kernel.org> # v3.17+
2019-12-06 14:51:12 -05:00

4476 lines
123 KiB
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/*
* Copyright © 2014 Red Hat
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that copyright
* notice and this permission notice appear in supporting documentation, and
* that the name of the copyright holders not be used in advertising or
* publicity pertaining to distribution of the software without specific,
* written prior permission. The copyright holders make no representations
* about the suitability of this software for any purpose. It is provided "as
* is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
* EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
* OF THIS SOFTWARE.
*/
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_dp_mst_helper.h>
#include <drm/drm_drv.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>
#include "drm_crtc_helper_internal.h"
#include "drm_dp_mst_topology_internal.h"
/**
* DOC: dp mst helper
*
* These functions contain parts of the DisplayPort 1.2a MultiStream Transport
* protocol. The helpers contain a topology manager and bandwidth manager.
* The helpers encapsulate the sending and received of sideband msgs.
*/
static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
char *buf);
static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port);
static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
int id,
struct drm_dp_payload *payload);
static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port,
int offset, int size, u8 *bytes);
static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port,
int offset, int size, u8 *bytes);
static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb);
static void
drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb);
static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb,
struct drm_dp_mst_port *port);
static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
u8 *guid);
static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux);
static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux);
static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
#define DBG_PREFIX "[dp_mst]"
#define DP_STR(x) [DP_ ## x] = #x
static const char *drm_dp_mst_req_type_str(u8 req_type)
{
static const char * const req_type_str[] = {
DP_STR(GET_MSG_TRANSACTION_VERSION),
DP_STR(LINK_ADDRESS),
DP_STR(CONNECTION_STATUS_NOTIFY),
DP_STR(ENUM_PATH_RESOURCES),
DP_STR(ALLOCATE_PAYLOAD),
DP_STR(QUERY_PAYLOAD),
DP_STR(RESOURCE_STATUS_NOTIFY),
DP_STR(CLEAR_PAYLOAD_ID_TABLE),
DP_STR(REMOTE_DPCD_READ),
DP_STR(REMOTE_DPCD_WRITE),
DP_STR(REMOTE_I2C_READ),
DP_STR(REMOTE_I2C_WRITE),
DP_STR(POWER_UP_PHY),
DP_STR(POWER_DOWN_PHY),
DP_STR(SINK_EVENT_NOTIFY),
DP_STR(QUERY_STREAM_ENC_STATUS),
};
if (req_type >= ARRAY_SIZE(req_type_str) ||
!req_type_str[req_type])
return "unknown";
return req_type_str[req_type];
}
#undef DP_STR
#define DP_STR(x) [DP_NAK_ ## x] = #x
static const char *drm_dp_mst_nak_reason_str(u8 nak_reason)
{
static const char * const nak_reason_str[] = {
DP_STR(WRITE_FAILURE),
DP_STR(INVALID_READ),
DP_STR(CRC_FAILURE),
DP_STR(BAD_PARAM),
DP_STR(DEFER),
DP_STR(LINK_FAILURE),
DP_STR(NO_RESOURCES),
DP_STR(DPCD_FAIL),
DP_STR(I2C_NAK),
DP_STR(ALLOCATE_FAIL),
};
if (nak_reason >= ARRAY_SIZE(nak_reason_str) ||
!nak_reason_str[nak_reason])
return "unknown";
return nak_reason_str[nak_reason];
}
#undef DP_STR
#define DP_STR(x) [DRM_DP_SIDEBAND_TX_ ## x] = #x
static const char *drm_dp_mst_sideband_tx_state_str(int state)
{
static const char * const sideband_reason_str[] = {
DP_STR(QUEUED),
DP_STR(START_SEND),
DP_STR(SENT),
DP_STR(RX),
DP_STR(TIMEOUT),
};
if (state >= ARRAY_SIZE(sideband_reason_str) ||
!sideband_reason_str[state])
return "unknown";
return sideband_reason_str[state];
}
static int
drm_dp_mst_rad_to_str(const u8 rad[8], u8 lct, char *out, size_t len)
{
int i;
u8 unpacked_rad[16];
for (i = 0; i < lct; i++) {
if (i % 2)
unpacked_rad[i] = rad[i / 2] >> 4;
else
unpacked_rad[i] = rad[i / 2] & BIT_MASK(4);
}
/* TODO: Eventually add something to printk so we can format the rad
* like this: 1.2.3
*/
return snprintf(out, len, "%*phC", lct, unpacked_rad);
}
/* sideband msg handling */
static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
{
u8 bitmask = 0x80;
u8 bitshift = 7;
u8 array_index = 0;
int number_of_bits = num_nibbles * 4;
u8 remainder = 0;
while (number_of_bits != 0) {
number_of_bits--;
remainder <<= 1;
remainder |= (data[array_index] & bitmask) >> bitshift;
bitmask >>= 1;
bitshift--;
if (bitmask == 0) {
bitmask = 0x80;
bitshift = 7;
array_index++;
}
if ((remainder & 0x10) == 0x10)
remainder ^= 0x13;
}
number_of_bits = 4;
while (number_of_bits != 0) {
number_of_bits--;
remainder <<= 1;
if ((remainder & 0x10) != 0)
remainder ^= 0x13;
}
return remainder;
}
static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
{
u8 bitmask = 0x80;
u8 bitshift = 7;
u8 array_index = 0;
int number_of_bits = number_of_bytes * 8;
u16 remainder = 0;
while (number_of_bits != 0) {
number_of_bits--;
remainder <<= 1;
remainder |= (data[array_index] & bitmask) >> bitshift;
bitmask >>= 1;
bitshift--;
if (bitmask == 0) {
bitmask = 0x80;
bitshift = 7;
array_index++;
}
if ((remainder & 0x100) == 0x100)
remainder ^= 0xd5;
}
number_of_bits = 8;
while (number_of_bits != 0) {
number_of_bits--;
remainder <<= 1;
if ((remainder & 0x100) != 0)
remainder ^= 0xd5;
}
return remainder & 0xff;
}
static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
{
u8 size = 3;
size += (hdr->lct / 2);
return size;
}
static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
u8 *buf, int *len)
{
int idx = 0;
int i;
u8 crc4;
buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
for (i = 0; i < (hdr->lct / 2); i++)
buf[idx++] = hdr->rad[i];
buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
(hdr->msg_len & 0x3f);
buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
buf[idx - 1] |= (crc4 & 0xf);
*len = idx;
}
static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
u8 *buf, int buflen, u8 *hdrlen)
{
u8 crc4;
u8 len;
int i;
u8 idx;
if (buf[0] == 0)
return false;
len = 3;
len += ((buf[0] & 0xf0) >> 4) / 2;
if (len > buflen)
return false;
crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
return false;
}
hdr->lct = (buf[0] & 0xf0) >> 4;
hdr->lcr = (buf[0] & 0xf);
idx = 1;
for (i = 0; i < (hdr->lct / 2); i++)
hdr->rad[i] = buf[idx++];
hdr->broadcast = (buf[idx] >> 7) & 0x1;
hdr->path_msg = (buf[idx] >> 6) & 0x1;
hdr->msg_len = buf[idx] & 0x3f;
idx++;
hdr->somt = (buf[idx] >> 7) & 0x1;
hdr->eomt = (buf[idx] >> 6) & 0x1;
hdr->seqno = (buf[idx] >> 4) & 0x1;
idx++;
*hdrlen = idx;
return true;
}
void
drm_dp_encode_sideband_req(const struct drm_dp_sideband_msg_req_body *req,
struct drm_dp_sideband_msg_tx *raw)
{
int idx = 0;
int i;
u8 *buf = raw->msg;
buf[idx++] = req->req_type & 0x7f;
switch (req->req_type) {
case DP_ENUM_PATH_RESOURCES:
case DP_POWER_DOWN_PHY:
case DP_POWER_UP_PHY:
buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
idx++;
break;
case DP_ALLOCATE_PAYLOAD:
buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
(req->u.allocate_payload.number_sdp_streams & 0xf);
idx++;
buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
idx++;
buf[idx] = (req->u.allocate_payload.pbn >> 8);
idx++;
buf[idx] = (req->u.allocate_payload.pbn & 0xff);
idx++;
for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
(req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
idx++;
}
if (req->u.allocate_payload.number_sdp_streams & 1) {
i = req->u.allocate_payload.number_sdp_streams - 1;
buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
idx++;
}
break;
case DP_QUERY_PAYLOAD:
buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
idx++;
buf[idx] = (req->u.query_payload.vcpi & 0x7f);
idx++;
break;
case DP_REMOTE_DPCD_READ:
buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
idx++;
buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
idx++;
buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
idx++;
buf[idx] = (req->u.dpcd_read.num_bytes);
idx++;
break;
case DP_REMOTE_DPCD_WRITE:
buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
idx++;
buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
idx++;
buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
idx++;
buf[idx] = (req->u.dpcd_write.num_bytes);
idx++;
memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
idx += req->u.dpcd_write.num_bytes;
break;
case DP_REMOTE_I2C_READ:
buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
idx++;
for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
idx++;
buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
idx++;
memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
idx += req->u.i2c_read.transactions[i].num_bytes;
buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 5;
buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
idx++;
}
buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
idx++;
buf[idx] = (req->u.i2c_read.num_bytes_read);
idx++;
break;
case DP_REMOTE_I2C_WRITE:
buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
idx++;
buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
idx++;
buf[idx] = (req->u.i2c_write.num_bytes);
idx++;
memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
idx += req->u.i2c_write.num_bytes;
break;
}
raw->cur_len = idx;
}
EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_encode_sideband_req);
/* Decode a sideband request we've encoded, mainly used for debugging */
int
drm_dp_decode_sideband_req(const struct drm_dp_sideband_msg_tx *raw,
struct drm_dp_sideband_msg_req_body *req)
{
const u8 *buf = raw->msg;
int i, idx = 0;
req->req_type = buf[idx++] & 0x7f;
switch (req->req_type) {
case DP_ENUM_PATH_RESOURCES:
case DP_POWER_DOWN_PHY:
case DP_POWER_UP_PHY:
req->u.port_num.port_number = (buf[idx] >> 4) & 0xf;
break;
case DP_ALLOCATE_PAYLOAD:
{
struct drm_dp_allocate_payload *a =
&req->u.allocate_payload;
a->number_sdp_streams = buf[idx] & 0xf;
a->port_number = (buf[idx] >> 4) & 0xf;
WARN_ON(buf[++idx] & 0x80);
a->vcpi = buf[idx] & 0x7f;
a->pbn = buf[++idx] << 8;
a->pbn |= buf[++idx];
idx++;
for (i = 0; i < a->number_sdp_streams; i++) {
a->sdp_stream_sink[i] =
(buf[idx + (i / 2)] >> ((i % 2) ? 0 : 4)) & 0xf;
}
}
break;
case DP_QUERY_PAYLOAD:
req->u.query_payload.port_number = (buf[idx] >> 4) & 0xf;
WARN_ON(buf[++idx] & 0x80);
req->u.query_payload.vcpi = buf[idx] & 0x7f;
break;
case DP_REMOTE_DPCD_READ:
{
struct drm_dp_remote_dpcd_read *r = &req->u.dpcd_read;
r->port_number = (buf[idx] >> 4) & 0xf;
r->dpcd_address = (buf[idx] << 16) & 0xf0000;
r->dpcd_address |= (buf[++idx] << 8) & 0xff00;
r->dpcd_address |= buf[++idx] & 0xff;
r->num_bytes = buf[++idx];
}
break;
case DP_REMOTE_DPCD_WRITE:
{
struct drm_dp_remote_dpcd_write *w =
&req->u.dpcd_write;
w->port_number = (buf[idx] >> 4) & 0xf;
w->dpcd_address = (buf[idx] << 16) & 0xf0000;
w->dpcd_address |= (buf[++idx] << 8) & 0xff00;
w->dpcd_address |= buf[++idx] & 0xff;
w->num_bytes = buf[++idx];
w->bytes = kmemdup(&buf[++idx], w->num_bytes,
GFP_KERNEL);
if (!w->bytes)
return -ENOMEM;
}
break;
case DP_REMOTE_I2C_READ:
{
struct drm_dp_remote_i2c_read *r = &req->u.i2c_read;
struct drm_dp_remote_i2c_read_tx *tx;
bool failed = false;
r->num_transactions = buf[idx] & 0x3;
r->port_number = (buf[idx] >> 4) & 0xf;
for (i = 0; i < r->num_transactions; i++) {
tx = &r->transactions[i];
tx->i2c_dev_id = buf[++idx] & 0x7f;
tx->num_bytes = buf[++idx];
tx->bytes = kmemdup(&buf[++idx],
tx->num_bytes,
GFP_KERNEL);
if (!tx->bytes) {
failed = true;
break;
}
idx += tx->num_bytes;
tx->no_stop_bit = (buf[idx] >> 5) & 0x1;
tx->i2c_transaction_delay = buf[idx] & 0xf;
}
if (failed) {
for (i = 0; i < r->num_transactions; i++) {
tx = &r->transactions[i];
kfree(tx->bytes);
}
return -ENOMEM;
}
r->read_i2c_device_id = buf[++idx] & 0x7f;
r->num_bytes_read = buf[++idx];
}
break;
case DP_REMOTE_I2C_WRITE:
{
struct drm_dp_remote_i2c_write *w = &req->u.i2c_write;
w->port_number = (buf[idx] >> 4) & 0xf;
w->write_i2c_device_id = buf[++idx] & 0x7f;
w->num_bytes = buf[++idx];
w->bytes = kmemdup(&buf[++idx], w->num_bytes,
GFP_KERNEL);
if (!w->bytes)
return -ENOMEM;
}
break;
}
return 0;
}
EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_decode_sideband_req);
void
drm_dp_dump_sideband_msg_req_body(const struct drm_dp_sideband_msg_req_body *req,
int indent, struct drm_printer *printer)
{
int i;
#define P(f, ...) drm_printf_indent(printer, indent, f, ##__VA_ARGS__)
if (req->req_type == DP_LINK_ADDRESS) {
/* No contents to print */
P("type=%s\n", drm_dp_mst_req_type_str(req->req_type));
return;
}
P("type=%s contents:\n", drm_dp_mst_req_type_str(req->req_type));
indent++;
switch (req->req_type) {
case DP_ENUM_PATH_RESOURCES:
case DP_POWER_DOWN_PHY:
case DP_POWER_UP_PHY:
P("port=%d\n", req->u.port_num.port_number);
break;
case DP_ALLOCATE_PAYLOAD:
P("port=%d vcpi=%d pbn=%d sdp_streams=%d %*ph\n",
req->u.allocate_payload.port_number,
req->u.allocate_payload.vcpi, req->u.allocate_payload.pbn,
req->u.allocate_payload.number_sdp_streams,
req->u.allocate_payload.number_sdp_streams,
req->u.allocate_payload.sdp_stream_sink);
break;
case DP_QUERY_PAYLOAD:
P("port=%d vcpi=%d\n",
req->u.query_payload.port_number,
req->u.query_payload.vcpi);
break;
case DP_REMOTE_DPCD_READ:
P("port=%d dpcd_addr=%05x len=%d\n",
req->u.dpcd_read.port_number, req->u.dpcd_read.dpcd_address,
req->u.dpcd_read.num_bytes);
break;
case DP_REMOTE_DPCD_WRITE:
P("port=%d addr=%05x len=%d: %*ph\n",
req->u.dpcd_write.port_number,
req->u.dpcd_write.dpcd_address,
req->u.dpcd_write.num_bytes, req->u.dpcd_write.num_bytes,
req->u.dpcd_write.bytes);
break;
case DP_REMOTE_I2C_READ:
P("port=%d num_tx=%d id=%d size=%d:\n",
req->u.i2c_read.port_number,
req->u.i2c_read.num_transactions,
req->u.i2c_read.read_i2c_device_id,
req->u.i2c_read.num_bytes_read);
indent++;
for (i = 0; i < req->u.i2c_read.num_transactions; i++) {
const struct drm_dp_remote_i2c_read_tx *rtx =
&req->u.i2c_read.transactions[i];
P("%d: id=%03d size=%03d no_stop_bit=%d tx_delay=%03d: %*ph\n",
i, rtx->i2c_dev_id, rtx->num_bytes,
rtx->no_stop_bit, rtx->i2c_transaction_delay,
rtx->num_bytes, rtx->bytes);
}
break;
case DP_REMOTE_I2C_WRITE:
P("port=%d id=%d size=%d: %*ph\n",
req->u.i2c_write.port_number,
req->u.i2c_write.write_i2c_device_id,
req->u.i2c_write.num_bytes, req->u.i2c_write.num_bytes,
req->u.i2c_write.bytes);
break;
default:
P("???\n");
break;
}
#undef P
}
EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_dump_sideband_msg_req_body);
static inline void
drm_dp_mst_dump_sideband_msg_tx(struct drm_printer *p,
const struct drm_dp_sideband_msg_tx *txmsg)
{
struct drm_dp_sideband_msg_req_body req;
char buf[64];
int ret;
int i;
drm_dp_mst_rad_to_str(txmsg->dst->rad, txmsg->dst->lct, buf,
sizeof(buf));
drm_printf(p, "txmsg cur_offset=%x cur_len=%x seqno=%x state=%s path_msg=%d dst=%s\n",
txmsg->cur_offset, txmsg->cur_len, txmsg->seqno,
drm_dp_mst_sideband_tx_state_str(txmsg->state),
txmsg->path_msg, buf);
ret = drm_dp_decode_sideband_req(txmsg, &req);
if (ret) {
drm_printf(p, "<failed to decode sideband req: %d>\n", ret);
return;
}
drm_dp_dump_sideband_msg_req_body(&req, 1, p);
switch (req.req_type) {
case DP_REMOTE_DPCD_WRITE:
kfree(req.u.dpcd_write.bytes);
break;
case DP_REMOTE_I2C_READ:
for (i = 0; i < req.u.i2c_read.num_transactions; i++)
kfree(req.u.i2c_read.transactions[i].bytes);
break;
case DP_REMOTE_I2C_WRITE:
kfree(req.u.i2c_write.bytes);
break;
}
}
static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
{
u8 crc4;
crc4 = drm_dp_msg_data_crc4(msg, len);
msg[len] = crc4;
}
static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
struct drm_dp_sideband_msg_tx *raw)
{
int idx = 0;
u8 *buf = raw->msg;
buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
raw->cur_len = idx;
}
/* this adds a chunk of msg to the builder to get the final msg */
static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
u8 *replybuf, u8 replybuflen, bool hdr)
{
int ret;
u8 crc4;
if (hdr) {
u8 hdrlen;
struct drm_dp_sideband_msg_hdr recv_hdr;
ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen);
if (ret == false) {
print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false);
return false;
}
/*
* ignore out-of-order messages or messages that are part of a
* failed transaction
*/
if (!recv_hdr.somt && !msg->have_somt)
return false;
/* get length contained in this portion */
msg->curchunk_len = recv_hdr.msg_len;
msg->curchunk_hdrlen = hdrlen;
/* we have already gotten an somt - don't bother parsing */
if (recv_hdr.somt && msg->have_somt)
return false;
if (recv_hdr.somt) {
memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr));
msg->have_somt = true;
}
if (recv_hdr.eomt)
msg->have_eomt = true;
/* copy the bytes for the remainder of this header chunk */
msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen));
memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx);
} else {
memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
msg->curchunk_idx += replybuflen;
}
if (msg->curchunk_idx >= msg->curchunk_len) {
/* do CRC */
crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
/* copy chunk into bigger msg */
memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
msg->curlen += msg->curchunk_len - 1;
}
return true;
}
static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
int i;
memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
idx += 16;
repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
idx++;
if (idx > raw->curlen)
goto fail_len;
for (i = 0; i < repmsg->u.link_addr.nports; i++) {
if (raw->msg[idx] & 0x80)
repmsg->u.link_addr.ports[i].input_port = 1;
repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
if (repmsg->u.link_addr.ports[i].input_port == 0)
repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
idx++;
if (idx > raw->curlen)
goto fail_len;
if (repmsg->u.link_addr.ports[i].input_port == 0) {
repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
idx++;
if (idx > raw->curlen)
goto fail_len;
memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
idx += 16;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
idx++;
}
if (idx > raw->curlen)
goto fail_len;
}
return true;
fail_len:
DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
idx++;
if (idx > raw->curlen)
goto fail_len;
memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
return true;
fail_len:
DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
idx++;
if (idx > raw->curlen)
goto fail_len;
return true;
fail_len:
DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
idx++;
/* TODO check */
memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
return true;
fail_len:
DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
idx += 2;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
idx += 2;
if (idx > raw->curlen)
goto fail_len;
return true;
fail_len:
DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.allocate_payload.vcpi = raw->msg[idx];
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
idx += 2;
if (idx > raw->curlen)
goto fail_len;
return true;
fail_len:
DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
idx += 2;
if (idx > raw->curlen)
goto fail_len;
return true;
fail_len:
DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.port_number.port_number = (raw->msg[idx] >> 4) & 0xf;
idx++;
if (idx > raw->curlen) {
DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n",
idx, raw->curlen);
return false;
}
return true;
}
static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *msg)
{
memset(msg, 0, sizeof(*msg));
msg->reply_type = (raw->msg[0] & 0x80) >> 7;
msg->req_type = (raw->msg[0] & 0x7f);
if (msg->reply_type == DP_SIDEBAND_REPLY_NAK) {
memcpy(msg->u.nak.guid, &raw->msg[1], 16);
msg->u.nak.reason = raw->msg[17];
msg->u.nak.nak_data = raw->msg[18];
return false;
}
switch (msg->req_type) {
case DP_LINK_ADDRESS:
return drm_dp_sideband_parse_link_address(raw, msg);
case DP_QUERY_PAYLOAD:
return drm_dp_sideband_parse_query_payload_ack(raw, msg);
case DP_REMOTE_DPCD_READ:
return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
case DP_REMOTE_DPCD_WRITE:
return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
case DP_REMOTE_I2C_READ:
return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
case DP_ENUM_PATH_RESOURCES:
return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
case DP_ALLOCATE_PAYLOAD:
return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
case DP_POWER_DOWN_PHY:
case DP_POWER_UP_PHY:
return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg);
case DP_CLEAR_PAYLOAD_ID_TABLE:
return true; /* since there's nothing to parse */
default:
DRM_ERROR("Got unknown reply 0x%02x (%s)\n", msg->req_type,
drm_dp_mst_req_type_str(msg->req_type));
return false;
}
}
static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_req_body *msg)
{
int idx = 1;
msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
idx++;
if (idx > raw->curlen)
goto fail_len;
memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
idx += 16;
if (idx > raw->curlen)
goto fail_len;
msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
idx++;
return true;
fail_len:
DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_req_body *msg)
{
int idx = 1;
msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
idx++;
if (idx > raw->curlen)
goto fail_len;
memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
idx += 16;
if (idx > raw->curlen)
goto fail_len;
msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
idx++;
return true;
fail_len:
DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_req_body *msg)
{
memset(msg, 0, sizeof(*msg));
msg->req_type = (raw->msg[0] & 0x7f);
switch (msg->req_type) {
case DP_CONNECTION_STATUS_NOTIFY:
return drm_dp_sideband_parse_connection_status_notify(raw, msg);
case DP_RESOURCE_STATUS_NOTIFY:
return drm_dp_sideband_parse_resource_status_notify(raw, msg);
default:
DRM_ERROR("Got unknown request 0x%02x (%s)\n", msg->req_type,
drm_dp_mst_req_type_str(msg->req_type));
return false;
}
}
static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
{
struct drm_dp_sideband_msg_req_body req;
req.req_type = DP_REMOTE_DPCD_WRITE;
req.u.dpcd_write.port_number = port_num;
req.u.dpcd_write.dpcd_address = offset;
req.u.dpcd_write.num_bytes = num_bytes;
req.u.dpcd_write.bytes = bytes;
drm_dp_encode_sideband_req(&req, msg);
return 0;
}
static int build_link_address(struct drm_dp_sideband_msg_tx *msg)
{
struct drm_dp_sideband_msg_req_body req;
req.req_type = DP_LINK_ADDRESS;
drm_dp_encode_sideband_req(&req, msg);
return 0;
}
static int build_clear_payload_id_table(struct drm_dp_sideband_msg_tx *msg)
{
struct drm_dp_sideband_msg_req_body req;
req.req_type = DP_CLEAR_PAYLOAD_ID_TABLE;
drm_dp_encode_sideband_req(&req, msg);
return 0;
}
static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num)
{
struct drm_dp_sideband_msg_req_body req;
req.req_type = DP_ENUM_PATH_RESOURCES;
req.u.port_num.port_number = port_num;
drm_dp_encode_sideband_req(&req, msg);
msg->path_msg = true;
return 0;
}
static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
u8 vcpi, uint16_t pbn,
u8 number_sdp_streams,
u8 *sdp_stream_sink)
{
struct drm_dp_sideband_msg_req_body req;
memset(&req, 0, sizeof(req));
req.req_type = DP_ALLOCATE_PAYLOAD;
req.u.allocate_payload.port_number = port_num;
req.u.allocate_payload.vcpi = vcpi;
req.u.allocate_payload.pbn = pbn;
req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
number_sdp_streams);
drm_dp_encode_sideband_req(&req, msg);
msg->path_msg = true;
return 0;
}
static int build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg,
int port_num, bool power_up)
{
struct drm_dp_sideband_msg_req_body req;
if (power_up)
req.req_type = DP_POWER_UP_PHY;
else
req.req_type = DP_POWER_DOWN_PHY;
req.u.port_num.port_number = port_num;
drm_dp_encode_sideband_req(&req, msg);
msg->path_msg = true;
return 0;
}
static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_vcpi *vcpi)
{
int ret, vcpi_ret;
mutex_lock(&mgr->payload_lock);
ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
if (ret > mgr->max_payloads) {
ret = -EINVAL;
DRM_DEBUG_KMS("out of payload ids %d\n", ret);
goto out_unlock;
}
vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
if (vcpi_ret > mgr->max_payloads) {
ret = -EINVAL;
DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
goto out_unlock;
}
set_bit(ret, &mgr->payload_mask);
set_bit(vcpi_ret, &mgr->vcpi_mask);
vcpi->vcpi = vcpi_ret + 1;
mgr->proposed_vcpis[ret - 1] = vcpi;
out_unlock:
mutex_unlock(&mgr->payload_lock);
return ret;
}
static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
int vcpi)
{
int i;
if (vcpi == 0)
return;
mutex_lock(&mgr->payload_lock);
DRM_DEBUG_KMS("putting payload %d\n", vcpi);
clear_bit(vcpi - 1, &mgr->vcpi_mask);
for (i = 0; i < mgr->max_payloads; i++) {
if (mgr->proposed_vcpis[i] &&
mgr->proposed_vcpis[i]->vcpi == vcpi) {
mgr->proposed_vcpis[i] = NULL;
clear_bit(i + 1, &mgr->payload_mask);
}
}
mutex_unlock(&mgr->payload_lock);
}
static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_sideband_msg_tx *txmsg)
{
unsigned int state;
/*
* All updates to txmsg->state are protected by mgr->qlock, and the two
* cases we check here are terminal states. For those the barriers
* provided by the wake_up/wait_event pair are enough.
*/
state = READ_ONCE(txmsg->state);
return (state == DRM_DP_SIDEBAND_TX_RX ||
state == DRM_DP_SIDEBAND_TX_TIMEOUT);
}
static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
struct drm_dp_sideband_msg_tx *txmsg)
{
struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
int ret;
ret = wait_event_timeout(mgr->tx_waitq,
check_txmsg_state(mgr, txmsg),
(4 * HZ));
mutex_lock(&mstb->mgr->qlock);
if (ret > 0) {
if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
ret = -EIO;
goto out;
}
} else {
DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
/* dump some state */
ret = -EIO;
/* remove from q */
if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
list_del(&txmsg->next);
}
if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
mstb->tx_slots[txmsg->seqno] = NULL;
}
}
out:
if (unlikely(ret == -EIO) && drm_debug_enabled(DRM_UT_DP)) {
struct drm_printer p = drm_debug_printer(DBG_PREFIX);
drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
}
mutex_unlock(&mgr->qlock);
return ret;
}
static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
{
struct drm_dp_mst_branch *mstb;
mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
if (!mstb)
return NULL;
mstb->lct = lct;
if (lct > 1)
memcpy(mstb->rad, rad, lct / 2);
INIT_LIST_HEAD(&mstb->ports);
kref_init(&mstb->topology_kref);
kref_init(&mstb->malloc_kref);
return mstb;
}
static void drm_dp_free_mst_branch_device(struct kref *kref)
{
struct drm_dp_mst_branch *mstb =
container_of(kref, struct drm_dp_mst_branch, malloc_kref);
if (mstb->port_parent)
drm_dp_mst_put_port_malloc(mstb->port_parent);
kfree(mstb);
}
/**
* DOC: Branch device and port refcounting
*
* Topology refcount overview
* ~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* The refcounting schemes for &struct drm_dp_mst_branch and &struct
* drm_dp_mst_port are somewhat unusual. Both ports and branch devices have
* two different kinds of refcounts: topology refcounts, and malloc refcounts.
*
* Topology refcounts are not exposed to drivers, and are handled internally
* by the DP MST helpers. The helpers use them in order to prevent the
* in-memory topology state from being changed in the middle of critical
* operations like changing the internal state of payload allocations. This
* means each branch and port will be considered to be connected to the rest
* of the topology until its topology refcount reaches zero. Additionally,
* for ports this means that their associated &struct drm_connector will stay
* registered with userspace until the port's refcount reaches 0.
*
* Malloc refcount overview
* ~~~~~~~~~~~~~~~~~~~~~~~~
*
* Malloc references are used to keep a &struct drm_dp_mst_port or &struct
* drm_dp_mst_branch allocated even after all of its topology references have
* been dropped, so that the driver or MST helpers can safely access each
* branch's last known state before it was disconnected from the topology.
* When the malloc refcount of a port or branch reaches 0, the memory
* allocation containing the &struct drm_dp_mst_branch or &struct
* drm_dp_mst_port respectively will be freed.
*
* For &struct drm_dp_mst_branch, malloc refcounts are not currently exposed
* to drivers. As of writing this documentation, there are no drivers that
* have a usecase for accessing &struct drm_dp_mst_branch outside of the MST
* helpers. Exposing this API to drivers in a race-free manner would take more
* tweaking of the refcounting scheme, however patches are welcome provided
* there is a legitimate driver usecase for this.
*
* Refcount relationships in a topology
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* Let's take a look at why the relationship between topology and malloc
* refcounts is designed the way it is.
*
* .. kernel-figure:: dp-mst/topology-figure-1.dot
*
* An example of topology and malloc refs in a DP MST topology with two
* active payloads. Topology refcount increments are indicated by solid
* lines, and malloc refcount increments are indicated by dashed lines.
* Each starts from the branch which incremented the refcount, and ends at
* the branch to which the refcount belongs to, i.e. the arrow points the
* same way as the C pointers used to reference a structure.
*
* As you can see in the above figure, every branch increments the topology
* refcount of its children, and increments the malloc refcount of its
* parent. Additionally, every payload increments the malloc refcount of its
* assigned port by 1.
*
* So, what would happen if MSTB #3 from the above figure was unplugged from
* the system, but the driver hadn't yet removed payload #2 from port #3? The
* topology would start to look like the figure below.
*
* .. kernel-figure:: dp-mst/topology-figure-2.dot
*
* Ports and branch devices which have been released from memory are
* colored grey, and references which have been removed are colored red.
*
* Whenever a port or branch device's topology refcount reaches zero, it will
* decrement the topology refcounts of all its children, the malloc refcount
* of its parent, and finally its own malloc refcount. For MSTB #4 and port
* #4, this means they both have been disconnected from the topology and freed
* from memory. But, because payload #2 is still holding a reference to port
* #3, port #3 is removed from the topology but its &struct drm_dp_mst_port
* is still accessible from memory. This also means port #3 has not yet
* decremented the malloc refcount of MSTB #3, so its &struct
* drm_dp_mst_branch will also stay allocated in memory until port #3's
* malloc refcount reaches 0.
*
* This relationship is necessary because in order to release payload #2, we
* need to be able to figure out the last relative of port #3 that's still
* connected to the topology. In this case, we would travel up the topology as
* shown below.
*
* .. kernel-figure:: dp-mst/topology-figure-3.dot
*
* And finally, remove payload #2 by communicating with port #2 through
* sideband transactions.
*/
/**
* drm_dp_mst_get_mstb_malloc() - Increment the malloc refcount of a branch
* device
* @mstb: The &struct drm_dp_mst_branch to increment the malloc refcount of
*
* Increments &drm_dp_mst_branch.malloc_kref. When
* &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
* will be released and @mstb may no longer be used.
*
* See also: drm_dp_mst_put_mstb_malloc()
*/
static void
drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch *mstb)
{
kref_get(&mstb->malloc_kref);
DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref));
}
/**
* drm_dp_mst_put_mstb_malloc() - Decrement the malloc refcount of a branch
* device
* @mstb: The &struct drm_dp_mst_branch to decrement the malloc refcount of
*
* Decrements &drm_dp_mst_branch.malloc_kref. When
* &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
* will be released and @mstb may no longer be used.
*
* See also: drm_dp_mst_get_mstb_malloc()
*/
static void
drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch *mstb)
{
DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref) - 1);
kref_put(&mstb->malloc_kref, drm_dp_free_mst_branch_device);
}
static void drm_dp_free_mst_port(struct kref *kref)
{
struct drm_dp_mst_port *port =
container_of(kref, struct drm_dp_mst_port, malloc_kref);
drm_dp_mst_put_mstb_malloc(port->parent);
kfree(port);
}
/**
* drm_dp_mst_get_port_malloc() - Increment the malloc refcount of an MST port
* @port: The &struct drm_dp_mst_port to increment the malloc refcount of
*
* Increments &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
* reaches 0, the memory allocation for @port will be released and @port may
* no longer be used.
*
* Because @port could potentially be freed at any time by the DP MST helpers
* if &drm_dp_mst_port.malloc_kref reaches 0, including during a call to this
* function, drivers that which to make use of &struct drm_dp_mst_port should
* ensure that they grab at least one main malloc reference to their MST ports
* in &drm_dp_mst_topology_cbs.add_connector. This callback is called before
* there is any chance for &drm_dp_mst_port.malloc_kref to reach 0.
*
* See also: drm_dp_mst_put_port_malloc()
*/
void
drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port)
{
kref_get(&port->malloc_kref);
DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref));
}
EXPORT_SYMBOL(drm_dp_mst_get_port_malloc);
/**
* drm_dp_mst_put_port_malloc() - Decrement the malloc refcount of an MST port
* @port: The &struct drm_dp_mst_port to decrement the malloc refcount of
*
* Decrements &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
* reaches 0, the memory allocation for @port will be released and @port may
* no longer be used.
*
* See also: drm_dp_mst_get_port_malloc()
*/
void
drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port)
{
DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref) - 1);
kref_put(&port->malloc_kref, drm_dp_free_mst_port);
}
EXPORT_SYMBOL(drm_dp_mst_put_port_malloc);
static void drm_dp_destroy_mst_branch_device(struct kref *kref)
{
struct drm_dp_mst_branch *mstb =
container_of(kref, struct drm_dp_mst_branch, topology_kref);
struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
struct drm_dp_mst_port *port, *tmp;
bool wake_tx = false;
mutex_lock(&mgr->lock);
list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
list_del(&port->next);
drm_dp_mst_topology_put_port(port);
}
mutex_unlock(&mgr->lock);
/* drop any tx slots msg */
mutex_lock(&mstb->mgr->qlock);
if (mstb->tx_slots[0]) {
mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
mstb->tx_slots[0] = NULL;
wake_tx = true;
}
if (mstb->tx_slots[1]) {
mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
mstb->tx_slots[1] = NULL;
wake_tx = true;
}
mutex_unlock(&mstb->mgr->qlock);
if (wake_tx)
wake_up_all(&mstb->mgr->tx_waitq);
drm_dp_mst_put_mstb_malloc(mstb);
}
/**
* drm_dp_mst_topology_try_get_mstb() - Increment the topology refcount of a
* branch device unless it's zero
* @mstb: &struct drm_dp_mst_branch to increment the topology refcount of
*
* Attempts to grab a topology reference to @mstb, if it hasn't yet been
* removed from the topology (e.g. &drm_dp_mst_branch.topology_kref has
* reached 0). Holding a topology reference implies that a malloc reference
* will be held to @mstb as long as the user holds the topology reference.
*
* Care should be taken to ensure that the user has at least one malloc
* reference to @mstb. If you already have a topology reference to @mstb, you
* should use drm_dp_mst_topology_get_mstb() instead.
*
* See also:
* drm_dp_mst_topology_get_mstb()
* drm_dp_mst_topology_put_mstb()
*
* Returns:
* * 1: A topology reference was grabbed successfully
* * 0: @port is no longer in the topology, no reference was grabbed
*/
static int __must_check
drm_dp_mst_topology_try_get_mstb(struct drm_dp_mst_branch *mstb)
{
int ret = kref_get_unless_zero(&mstb->topology_kref);
if (ret)
DRM_DEBUG("mstb %p (%d)\n", mstb,
kref_read(&mstb->topology_kref));
return ret;
}
/**
* drm_dp_mst_topology_get_mstb() - Increment the topology refcount of a
* branch device
* @mstb: The &struct drm_dp_mst_branch to increment the topology refcount of
*
* Increments &drm_dp_mst_branch.topology_refcount without checking whether or
* not it's already reached 0. This is only valid to use in scenarios where
* you are already guaranteed to have at least one active topology reference
* to @mstb. Otherwise, drm_dp_mst_topology_try_get_mstb() must be used.
*
* See also:
* drm_dp_mst_topology_try_get_mstb()
* drm_dp_mst_topology_put_mstb()
*/
static void drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch *mstb)
{
WARN_ON(kref_read(&mstb->topology_kref) == 0);
kref_get(&mstb->topology_kref);
DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref));
}
/**
* drm_dp_mst_topology_put_mstb() - release a topology reference to a branch
* device
* @mstb: The &struct drm_dp_mst_branch to release the topology reference from
*
* Releases a topology reference from @mstb by decrementing
* &drm_dp_mst_branch.topology_kref.
*
* See also:
* drm_dp_mst_topology_try_get_mstb()
* drm_dp_mst_topology_get_mstb()
*/
static void
drm_dp_mst_topology_put_mstb(struct drm_dp_mst_branch *mstb)
{
DRM_DEBUG("mstb %p (%d)\n",
mstb, kref_read(&mstb->topology_kref) - 1);
kref_put(&mstb->topology_kref, drm_dp_destroy_mst_branch_device);
}
static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
{
struct drm_dp_mst_branch *mstb;
switch (old_pdt) {
case DP_PEER_DEVICE_DP_LEGACY_CONV:
case DP_PEER_DEVICE_SST_SINK:
/* remove i2c over sideband */
drm_dp_mst_unregister_i2c_bus(&port->aux);
break;
case DP_PEER_DEVICE_MST_BRANCHING:
mstb = port->mstb;
port->mstb = NULL;
drm_dp_mst_topology_put_mstb(mstb);
break;
}
}
static void drm_dp_destroy_port(struct kref *kref)
{
struct drm_dp_mst_port *port =
container_of(kref, struct drm_dp_mst_port, topology_kref);
struct drm_dp_mst_topology_mgr *mgr = port->mgr;
if (!port->input) {
kfree(port->cached_edid);
/*
* The only time we don't have a connector
* on an output port is if the connector init
* fails.
*/
if (port->connector) {
/* we can't destroy the connector here, as
* we might be holding the mode_config.mutex
* from an EDID retrieval */
mutex_lock(&mgr->destroy_connector_lock);
list_add(&port->next, &mgr->destroy_connector_list);
mutex_unlock(&mgr->destroy_connector_lock);
schedule_work(&mgr->destroy_connector_work);
return;
}
/* no need to clean up vcpi
* as if we have no connector we never setup a vcpi */
drm_dp_port_teardown_pdt(port, port->pdt);
port->pdt = DP_PEER_DEVICE_NONE;
}
drm_dp_mst_put_port_malloc(port);
}
/**
* drm_dp_mst_topology_try_get_port() - Increment the topology refcount of a
* port unless it's zero
* @port: &struct drm_dp_mst_port to increment the topology refcount of
*
* Attempts to grab a topology reference to @port, if it hasn't yet been
* removed from the topology (e.g. &drm_dp_mst_port.topology_kref has reached
* 0). Holding a topology reference implies that a malloc reference will be
* held to @port as long as the user holds the topology reference.
*
* Care should be taken to ensure that the user has at least one malloc
* reference to @port. If you already have a topology reference to @port, you
* should use drm_dp_mst_topology_get_port() instead.
*
* See also:
* drm_dp_mst_topology_get_port()
* drm_dp_mst_topology_put_port()
*
* Returns:
* * 1: A topology reference was grabbed successfully
* * 0: @port is no longer in the topology, no reference was grabbed
*/
static int __must_check
drm_dp_mst_topology_try_get_port(struct drm_dp_mst_port *port)
{
int ret = kref_get_unless_zero(&port->topology_kref);
if (ret)
DRM_DEBUG("port %p (%d)\n", port,
kref_read(&port->topology_kref));
return ret;
}
/**
* drm_dp_mst_topology_get_port() - Increment the topology refcount of a port
* @port: The &struct drm_dp_mst_port to increment the topology refcount of
*
* Increments &drm_dp_mst_port.topology_refcount without checking whether or
* not it's already reached 0. This is only valid to use in scenarios where
* you are already guaranteed to have at least one active topology reference
* to @port. Otherwise, drm_dp_mst_topology_try_get_port() must be used.
*
* See also:
* drm_dp_mst_topology_try_get_port()
* drm_dp_mst_topology_put_port()
*/
static void drm_dp_mst_topology_get_port(struct drm_dp_mst_port *port)
{
WARN_ON(kref_read(&port->topology_kref) == 0);
kref_get(&port->topology_kref);
DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->topology_kref));
}
/**
* drm_dp_mst_topology_put_port() - release a topology reference to a port
* @port: The &struct drm_dp_mst_port to release the topology reference from
*
* Releases a topology reference from @port by decrementing
* &drm_dp_mst_port.topology_kref.
*
* See also:
* drm_dp_mst_topology_try_get_port()
* drm_dp_mst_topology_get_port()
*/
static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port)
{
DRM_DEBUG("port %p (%d)\n",
port, kref_read(&port->topology_kref) - 1);
kref_put(&port->topology_kref, drm_dp_destroy_port);
}
static struct drm_dp_mst_branch *
drm_dp_mst_topology_get_mstb_validated_locked(struct drm_dp_mst_branch *mstb,
struct drm_dp_mst_branch *to_find)
{
struct drm_dp_mst_port *port;
struct drm_dp_mst_branch *rmstb;
if (to_find == mstb)
return mstb;
list_for_each_entry(port, &mstb->ports, next) {
if (port->mstb) {
rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
port->mstb, to_find);
if (rmstb)
return rmstb;
}
}
return NULL;
}
static struct drm_dp_mst_branch *
drm_dp_mst_topology_get_mstb_validated(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb)
{
struct drm_dp_mst_branch *rmstb = NULL;
mutex_lock(&mgr->lock);
if (mgr->mst_primary) {
rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
mgr->mst_primary, mstb);
if (rmstb && !drm_dp_mst_topology_try_get_mstb(rmstb))
rmstb = NULL;
}
mutex_unlock(&mgr->lock);
return rmstb;
}
static struct drm_dp_mst_port *
drm_dp_mst_topology_get_port_validated_locked(struct drm_dp_mst_branch *mstb,
struct drm_dp_mst_port *to_find)
{
struct drm_dp_mst_port *port, *mport;
list_for_each_entry(port, &mstb->ports, next) {
if (port == to_find)
return port;
if (port->mstb) {
mport = drm_dp_mst_topology_get_port_validated_locked(
port->mstb, to_find);
if (mport)
return mport;
}
}
return NULL;
}
static struct drm_dp_mst_port *
drm_dp_mst_topology_get_port_validated(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port)
{
struct drm_dp_mst_port *rport = NULL;
mutex_lock(&mgr->lock);
if (mgr->mst_primary) {
rport = drm_dp_mst_topology_get_port_validated_locked(
mgr->mst_primary, port);
if (rport && !drm_dp_mst_topology_try_get_port(rport))
rport = NULL;
}
mutex_unlock(&mgr->lock);
return rport;
}
static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
{
struct drm_dp_mst_port *port;
int ret;
list_for_each_entry(port, &mstb->ports, next) {
if (port->port_num == port_num) {
ret = drm_dp_mst_topology_try_get_port(port);
return ret ? port : NULL;
}
}
return NULL;
}
/*
* calculate a new RAD for this MST branch device
* if parent has an LCT of 2 then it has 1 nibble of RAD,
* if parent has an LCT of 3 then it has 2 nibbles of RAD,
*/
static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
u8 *rad)
{
int parent_lct = port->parent->lct;
int shift = 4;
int idx = (parent_lct - 1) / 2;
if (parent_lct > 1) {
memcpy(rad, port->parent->rad, idx + 1);
shift = (parent_lct % 2) ? 4 : 0;
} else
rad[0] = 0;
rad[idx] |= port->port_num << shift;
return parent_lct + 1;
}
/*
* return sends link address for new mstb
*/
static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
{
int ret;
u8 rad[6], lct;
bool send_link = false;
switch (port->pdt) {
case DP_PEER_DEVICE_DP_LEGACY_CONV:
case DP_PEER_DEVICE_SST_SINK:
/* add i2c over sideband */
ret = drm_dp_mst_register_i2c_bus(&port->aux);
break;
case DP_PEER_DEVICE_MST_BRANCHING:
lct = drm_dp_calculate_rad(port, rad);
port->mstb = drm_dp_add_mst_branch_device(lct, rad);
if (port->mstb) {
port->mstb->mgr = port->mgr;
port->mstb->port_parent = port;
/*
* Make sure this port's memory allocation stays
* around until its child MSTB releases it
*/
drm_dp_mst_get_port_malloc(port);
send_link = true;
}
break;
}
return send_link;
}
/**
* drm_dp_mst_dpcd_read() - read a series of bytes from the DPCD via sideband
* @aux: Fake sideband AUX CH
* @offset: address of the (first) register to read
* @buffer: buffer to store the register values
* @size: number of bytes in @buffer
*
* Performs the same functionality for remote devices via
* sideband messaging as drm_dp_dpcd_read() does for local
* devices via actual AUX CH.
*
* Return: Number of bytes read, or negative error code on failure.
*/
ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux,
unsigned int offset, void *buffer, size_t size)
{
struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
aux);
return drm_dp_send_dpcd_read(port->mgr, port,
offset, size, buffer);
}
/**
* drm_dp_mst_dpcd_write() - write a series of bytes to the DPCD via sideband
* @aux: Fake sideband AUX CH
* @offset: address of the (first) register to write
* @buffer: buffer containing the values to write
* @size: number of bytes in @buffer
*
* Performs the same functionality for remote devices via
* sideband messaging as drm_dp_dpcd_write() does for local
* devices via actual AUX CH.
*
* Return: 0 on success, negative error code on failure.
*/
ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux,
unsigned int offset, void *buffer, size_t size)
{
struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
aux);
return drm_dp_send_dpcd_write(port->mgr, port,
offset, size, buffer);
}
static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
{
int ret;
memcpy(mstb->guid, guid, 16);
if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
if (mstb->port_parent) {
ret = drm_dp_send_dpcd_write(
mstb->mgr,
mstb->port_parent,
DP_GUID,
16,
mstb->guid);
} else {
ret = drm_dp_dpcd_write(
mstb->mgr->aux,
DP_GUID,
mstb->guid,
16);
}
}
}
static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
int pnum,
char *proppath,
size_t proppath_size)
{
int i;
char temp[8];
snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
for (i = 0; i < (mstb->lct - 1); i++) {
int shift = (i % 2) ? 0 : 4;
int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
snprintf(temp, sizeof(temp), "-%d", port_num);
strlcat(proppath, temp, proppath_size);
}
snprintf(temp, sizeof(temp), "-%d", pnum);
strlcat(proppath, temp, proppath_size);
}
/**
* drm_dp_mst_connector_late_register() - Late MST connector registration
* @connector: The MST connector
* @port: The MST port for this connector
*
* Helper to register the remote aux device for this MST port. Drivers should
* call this from their mst connector's late_register hook to enable MST aux
* devices.
*
* Return: 0 on success, negative error code on failure.
*/
int drm_dp_mst_connector_late_register(struct drm_connector *connector,
struct drm_dp_mst_port *port)
{
DRM_DEBUG_KMS("registering %s remote bus for %s\n",
port->aux.name, connector->kdev->kobj.name);
port->aux.dev = connector->kdev;
return drm_dp_aux_register_devnode(&port->aux);
}
EXPORT_SYMBOL(drm_dp_mst_connector_late_register);
/**
* drm_dp_mst_connector_early_unregister() - Early MST connector unregistration
* @connector: The MST connector
* @port: The MST port for this connector
*
* Helper to unregister the remote aux device for this MST port, registered by
* drm_dp_mst_connector_late_register(). Drivers should call this from their mst
* connector's early_unregister hook.
*/
void drm_dp_mst_connector_early_unregister(struct drm_connector *connector,
struct drm_dp_mst_port *port)
{
DRM_DEBUG_KMS("unregistering %s remote bus for %s\n",
port->aux.name, connector->kdev->kobj.name);
drm_dp_aux_unregister_devnode(&port->aux);
}
EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister);
static void
drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
struct drm_device *dev,
struct drm_dp_link_addr_reply_port *port_msg)
{
struct drm_dp_mst_port *port;
bool ret;
bool created = false;
int old_pdt = 0;
int old_ddps = 0;
port = drm_dp_get_port(mstb, port_msg->port_number);
if (!port) {
port = kzalloc(sizeof(*port), GFP_KERNEL);
if (!port)
return;
kref_init(&port->topology_kref);
kref_init(&port->malloc_kref);
port->parent = mstb;
port->port_num = port_msg->port_number;
port->mgr = mstb->mgr;
port->aux.name = "DPMST";
port->aux.dev = dev->dev;
port->aux.is_remote = true;
/*
* Make sure the memory allocation for our parent branch stays
* around until our own memory allocation is released
*/
drm_dp_mst_get_mstb_malloc(mstb);
created = true;
} else {
old_pdt = port->pdt;
old_ddps = port->ddps;
}
port->pdt = port_msg->peer_device_type;
port->input = port_msg->input_port;
port->mcs = port_msg->mcs;
port->ddps = port_msg->ddps;
port->ldps = port_msg->legacy_device_plug_status;
port->dpcd_rev = port_msg->dpcd_revision;
port->num_sdp_streams = port_msg->num_sdp_streams;
port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
/* manage mstb port lists with mgr lock - take a reference
for this list */
if (created) {
mutex_lock(&mstb->mgr->lock);
drm_dp_mst_topology_get_port(port);
list_add(&port->next, &mstb->ports);
mutex_unlock(&mstb->mgr->lock);
}
if (old_ddps != port->ddps) {
if (port->ddps) {
if (!port->input) {
drm_dp_send_enum_path_resources(mstb->mgr,
mstb, port);
}
} else {
port->available_pbn = 0;
}
}
if (old_pdt != port->pdt && !port->input) {
drm_dp_port_teardown_pdt(port, old_pdt);
ret = drm_dp_port_setup_pdt(port);
if (ret == true)
drm_dp_send_link_address(mstb->mgr, port->mstb);
}
if (created && !port->input) {
char proppath[255];
build_mst_prop_path(mstb, port->port_num, proppath,
sizeof(proppath));
port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr,
port,
proppath);
if (!port->connector) {
/* remove it from the port list */
mutex_lock(&mstb->mgr->lock);
list_del(&port->next);
mutex_unlock(&mstb->mgr->lock);
/* drop port list reference */
drm_dp_mst_topology_put_port(port);
goto out;
}
if ((port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV ||
port->pdt == DP_PEER_DEVICE_SST_SINK) &&
port->port_num >= DP_MST_LOGICAL_PORT_0) {
port->cached_edid = drm_get_edid(port->connector,
&port->aux.ddc);
drm_connector_set_tile_property(port->connector);
}
(*mstb->mgr->cbs->register_connector)(port->connector);
}
out:
/* put reference to this port */
drm_dp_mst_topology_put_port(port);
}
static void
drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
struct drm_dp_connection_status_notify *conn_stat)
{
struct drm_dp_mst_port *port;
int old_pdt;
int old_ddps;
bool dowork = false;
port = drm_dp_get_port(mstb, conn_stat->port_number);
if (!port)
return;
old_ddps = port->ddps;
old_pdt = port->pdt;
port->pdt = conn_stat->peer_device_type;
port->mcs = conn_stat->message_capability_status;
port->ldps = conn_stat->legacy_device_plug_status;
port->ddps = conn_stat->displayport_device_plug_status;
if (old_ddps != port->ddps) {
if (port->ddps) {
dowork = true;
} else {
port->available_pbn = 0;
}
}
if (old_pdt != port->pdt && !port->input) {
drm_dp_port_teardown_pdt(port, old_pdt);
if (drm_dp_port_setup_pdt(port))
dowork = true;
}
drm_dp_mst_topology_put_port(port);
if (dowork)
queue_work(system_long_wq, &mstb->mgr->work);
}
static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
u8 lct, u8 *rad)
{
struct drm_dp_mst_branch *mstb;
struct drm_dp_mst_port *port;
int i, ret;
/* find the port by iterating down */
mutex_lock(&mgr->lock);
mstb = mgr->mst_primary;
if (!mstb)
goto out;
for (i = 0; i < lct - 1; i++) {
int shift = (i % 2) ? 0 : 4;
int port_num = (rad[i / 2] >> shift) & 0xf;
list_for_each_entry(port, &mstb->ports, next) {
if (port->port_num == port_num) {
mstb = port->mstb;
if (!mstb) {
DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
goto out;
}
break;
}
}
}
ret = drm_dp_mst_topology_try_get_mstb(mstb);
if (!ret)
mstb = NULL;
out:
mutex_unlock(&mgr->lock);
return mstb;
}
static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
struct drm_dp_mst_branch *mstb,
const uint8_t *guid)
{
struct drm_dp_mst_branch *found_mstb;
struct drm_dp_mst_port *port;
if (memcmp(mstb->guid, guid, 16) == 0)
return mstb;
list_for_each_entry(port, &mstb->ports, next) {
if (!port->mstb)
continue;
found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
if (found_mstb)
return found_mstb;
}
return NULL;
}
static struct drm_dp_mst_branch *
drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr *mgr,
const uint8_t *guid)
{
struct drm_dp_mst_branch *mstb;
int ret;
/* find the port by iterating down */
mutex_lock(&mgr->lock);
mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
if (mstb) {
ret = drm_dp_mst_topology_try_get_mstb(mstb);
if (!ret)
mstb = NULL;
}
mutex_unlock(&mgr->lock);
return mstb;
}
static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb)
{
struct drm_dp_mst_port *port;
struct drm_dp_mst_branch *mstb_child;
if (!mstb->link_address_sent)
drm_dp_send_link_address(mgr, mstb);
list_for_each_entry(port, &mstb->ports, next) {
if (port->input)
continue;
if (!port->ddps)
continue;
if (!port->available_pbn)
drm_dp_send_enum_path_resources(mgr, mstb, port);
if (port->mstb) {
mstb_child = drm_dp_mst_topology_get_mstb_validated(
mgr, port->mstb);
if (mstb_child) {
drm_dp_check_and_send_link_address(mgr, mstb_child);
drm_dp_mst_topology_put_mstb(mstb_child);
}
}
}
}
static void drm_dp_mst_link_probe_work(struct work_struct *work)
{
struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
struct drm_dp_mst_branch *mstb;
int ret;
bool clear_payload_id_table;
mutex_lock(&mgr->lock);
clear_payload_id_table = !mgr->payload_id_table_cleared;
mgr->payload_id_table_cleared = true;
mstb = mgr->mst_primary;
if (mstb) {
ret = drm_dp_mst_topology_try_get_mstb(mstb);
if (!ret)
mstb = NULL;
}
mutex_unlock(&mgr->lock);
if (!mstb)
return;
/*
* Certain branch devices seem to incorrectly report an available_pbn
* of 0 on downstream sinks, even after clearing the
* DP_PAYLOAD_ALLOCATE_* registers in
* drm_dp_mst_topology_mgr_set_mst(). Namely, the CableMatters USB-C
* 2x DP hub. Sending a CLEAR_PAYLOAD_ID_TABLE message seems to make
* things work again.
*/
if (clear_payload_id_table) {
DRM_DEBUG_KMS("Clearing payload ID table\n");
drm_dp_send_clear_payload_id_table(mgr, mstb);
}
drm_dp_check_and_send_link_address(mgr, mstb);
drm_dp_mst_topology_put_mstb(mstb);
}
static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
u8 *guid)
{
u64 salt;
if (memchr_inv(guid, 0, 16))
return true;
salt = get_jiffies_64();
memcpy(&guid[0], &salt, sizeof(u64));
memcpy(&guid[8], &salt, sizeof(u64));
return false;
}
static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
{
struct drm_dp_sideband_msg_req_body req;
req.req_type = DP_REMOTE_DPCD_READ;
req.u.dpcd_read.port_number = port_num;
req.u.dpcd_read.dpcd_address = offset;
req.u.dpcd_read.num_bytes = num_bytes;
drm_dp_encode_sideband_req(&req, msg);
return 0;
}
static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
bool up, u8 *msg, int len)
{
int ret;
int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
int tosend, total, offset;
int retries = 0;
retry:
total = len;
offset = 0;
do {
tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
&msg[offset],
tosend);
if (ret != tosend) {
if (ret == -EIO && retries < 5) {
retries++;
goto retry;
}
DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
return -EIO;
}
offset += tosend;
total -= tosend;
} while (total > 0);
return 0;
}
static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
struct drm_dp_sideband_msg_tx *txmsg)
{
struct drm_dp_mst_branch *mstb = txmsg->dst;
u8 req_type;
/* both msg slots are full */
if (txmsg->seqno == -1) {
if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
return -EAGAIN;
}
if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
txmsg->seqno = mstb->last_seqno;
mstb->last_seqno ^= 1;
} else if (mstb->tx_slots[0] == NULL)
txmsg->seqno = 0;
else
txmsg->seqno = 1;
mstb->tx_slots[txmsg->seqno] = txmsg;
}
req_type = txmsg->msg[0] & 0x7f;
if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
req_type == DP_RESOURCE_STATUS_NOTIFY)
hdr->broadcast = 1;
else
hdr->broadcast = 0;
hdr->path_msg = txmsg->path_msg;
hdr->lct = mstb->lct;
hdr->lcr = mstb->lct - 1;
if (mstb->lct > 1)
memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
hdr->seqno = txmsg->seqno;
return 0;
}
/*
* process a single block of the next message in the sideband queue
*/
static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_sideband_msg_tx *txmsg,
bool up)
{
u8 chunk[48];
struct drm_dp_sideband_msg_hdr hdr;
int len, space, idx, tosend;
int ret;
memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
txmsg->seqno = -1;
txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
}
/* make hdr from dst mst - for replies use seqno
otherwise assign one */
ret = set_hdr_from_dst_qlock(&hdr, txmsg);
if (ret < 0)
return ret;
/* amount left to send in this message */
len = txmsg->cur_len - txmsg->cur_offset;
/* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
tosend = min(len, space);
if (len == txmsg->cur_len)
hdr.somt = 1;
if (space >= len)
hdr.eomt = 1;
hdr.msg_len = tosend + 1;
drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
/* add crc at end */
drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
idx += tosend + 1;
ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
if (unlikely(ret) && drm_debug_enabled(DRM_UT_DP)) {
struct drm_printer p = drm_debug_printer(DBG_PREFIX);
drm_printf(&p, "sideband msg failed to send\n");
drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
return ret;
}
txmsg->cur_offset += tosend;
if (txmsg->cur_offset == txmsg->cur_len) {
txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
return 1;
}
return 0;
}
static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
{
struct drm_dp_sideband_msg_tx *txmsg;
int ret;
WARN_ON(!mutex_is_locked(&mgr->qlock));
/* construct a chunk from the first msg in the tx_msg queue */
if (list_empty(&mgr->tx_msg_downq))
return;
txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
ret = process_single_tx_qlock(mgr, txmsg, false);
if (ret == 1) {
/* txmsg is sent it should be in the slots now */
list_del(&txmsg->next);
} else if (ret) {
DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
list_del(&txmsg->next);
if (txmsg->seqno != -1)
txmsg->dst->tx_slots[txmsg->seqno] = NULL;
txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
wake_up_all(&mgr->tx_waitq);
}
}
/* called holding qlock */
static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_sideband_msg_tx *txmsg)
{
int ret;
/* construct a chunk from the first msg in the tx_msg queue */
ret = process_single_tx_qlock(mgr, txmsg, true);
if (ret != 1)
DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
if (txmsg->seqno != -1) {
WARN_ON((unsigned int)txmsg->seqno >
ARRAY_SIZE(txmsg->dst->tx_slots));
txmsg->dst->tx_slots[txmsg->seqno] = NULL;
}
}
static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_sideband_msg_tx *txmsg)
{
mutex_lock(&mgr->qlock);
list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
if (drm_debug_enabled(DRM_UT_DP)) {
struct drm_printer p = drm_debug_printer(DBG_PREFIX);
drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
}
if (list_is_singular(&mgr->tx_msg_downq))
process_single_down_tx_qlock(mgr);
mutex_unlock(&mgr->qlock);
}
static void
drm_dp_dump_link_address(struct drm_dp_link_address_ack_reply *reply)
{
struct drm_dp_link_addr_reply_port *port_reply;
int i;
for (i = 0; i < reply->nports; i++) {
port_reply = &reply->ports[i];
DRM_DEBUG_KMS("port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n",
i,
port_reply->input_port,
port_reply->peer_device_type,
port_reply->port_number,
port_reply->dpcd_revision,
port_reply->mcs,
port_reply->ddps,
port_reply->legacy_device_plug_status,
port_reply->num_sdp_streams,
port_reply->num_sdp_stream_sinks);
}
}
static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb)
{
struct drm_dp_sideband_msg_tx *txmsg;
struct drm_dp_link_address_ack_reply *reply;
int i, len, ret;
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg)
return;
txmsg->dst = mstb;
len = build_link_address(txmsg);
mstb->link_address_sent = true;
drm_dp_queue_down_tx(mgr, txmsg);
/* FIXME: Actually do some real error handling here */
ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
if (ret <= 0) {
DRM_ERROR("Sending link address failed with %d\n", ret);
goto out;
}
if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
DRM_ERROR("link address NAK received\n");
ret = -EIO;
goto out;
}
reply = &txmsg->reply.u.link_addr;
DRM_DEBUG_KMS("link address reply: %d\n", reply->nports);
drm_dp_dump_link_address(reply);
drm_dp_check_mstb_guid(mstb, reply->guid);
for (i = 0; i < reply->nports; i++)
drm_dp_mst_handle_link_address_port(mstb, mgr->dev,
&reply->ports[i]);
drm_kms_helper_hotplug_event(mgr->dev);
out:
if (ret <= 0)
mstb->link_address_sent = false;
kfree(txmsg);
}
void drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb)
{
struct drm_dp_sideband_msg_tx *txmsg;
int len, ret;
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg)
return;
txmsg->dst = mstb;
len = build_clear_payload_id_table(txmsg);
drm_dp_queue_down_tx(mgr, txmsg);
ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
if (ret > 0 && txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
DRM_DEBUG_KMS("clear payload table id nak received\n");
kfree(txmsg);
}
static int
drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb,
struct drm_dp_mst_port *port)
{
struct drm_dp_enum_path_resources_ack_reply *path_res;
struct drm_dp_sideband_msg_tx *txmsg;
int len;
int ret;
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg)
return -ENOMEM;
txmsg->dst = mstb;
len = build_enum_path_resources(txmsg, port->port_num);
drm_dp_queue_down_tx(mgr, txmsg);
ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
if (ret > 0) {
path_res = &txmsg->reply.u.path_resources;
if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
DRM_DEBUG_KMS("enum path resources nak received\n");
} else {
if (port->port_num != path_res->port_number)
DRM_ERROR("got incorrect port in response\n");
DRM_DEBUG_KMS("enum path resources %d: %d %d\n",
path_res->port_number,
path_res->full_payload_bw_number,
path_res->avail_payload_bw_number);
port->available_pbn =
path_res->avail_payload_bw_number;
}
}
kfree(txmsg);
return 0;
}
static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
{
if (!mstb->port_parent)
return NULL;
if (mstb->port_parent->mstb != mstb)
return mstb->port_parent;
return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
}
/*
* Searches upwards in the topology starting from mstb to try to find the
* closest available parent of mstb that's still connected to the rest of the
* topology. This can be used in order to perform operations like releasing
* payloads, where the branch device which owned the payload may no longer be
* around and thus would require that the payload on the last living relative
* be freed instead.
*/
static struct drm_dp_mst_branch *
drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb,
int *port_num)
{
struct drm_dp_mst_branch *rmstb = NULL;
struct drm_dp_mst_port *found_port;
mutex_lock(&mgr->lock);
if (!mgr->mst_primary)
goto out;
do {
found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
if (!found_port)
break;
if (drm_dp_mst_topology_try_get_mstb(found_port->parent)) {
rmstb = found_port->parent;
*port_num = found_port->port_num;
} else {
/* Search again, starting from this parent */
mstb = found_port->parent;
}
} while (!rmstb);
out:
mutex_unlock(&mgr->lock);
return rmstb;
}
static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port,
int id,
int pbn)
{
struct drm_dp_sideband_msg_tx *txmsg;
struct drm_dp_mst_branch *mstb;
int len, ret, port_num;
u8 sinks[DRM_DP_MAX_SDP_STREAMS];
int i;
port_num = port->port_num;
mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
if (!mstb) {
mstb = drm_dp_get_last_connected_port_and_mstb(mgr,
port->parent,
&port_num);
if (!mstb)
return -EINVAL;
}
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg) {
ret = -ENOMEM;
goto fail_put;
}
for (i = 0; i < port->num_sdp_streams; i++)
sinks[i] = i;
txmsg->dst = mstb;
len = build_allocate_payload(txmsg, port_num,
id,
pbn, port->num_sdp_streams, sinks);
drm_dp_queue_down_tx(mgr, txmsg);
/*
* FIXME: there is a small chance that between getting the last
* connected mstb and sending the payload message, the last connected
* mstb could also be removed from the topology. In the future, this
* needs to be fixed by restarting the
* drm_dp_get_last_connected_port_and_mstb() search in the event of a
* timeout if the topology is still connected to the system.
*/
ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
if (ret > 0) {
if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
ret = -EINVAL;
else
ret = 0;
}
kfree(txmsg);
fail_put:
drm_dp_mst_topology_put_mstb(mstb);
return ret;
}
int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port, bool power_up)
{
struct drm_dp_sideband_msg_tx *txmsg;
int len, ret;
port = drm_dp_mst_topology_get_port_validated(mgr, port);
if (!port)
return -EINVAL;
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg) {
drm_dp_mst_topology_put_port(port);
return -ENOMEM;
}
txmsg->dst = port->parent;
len = build_power_updown_phy(txmsg, port->port_num, power_up);
drm_dp_queue_down_tx(mgr, txmsg);
ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg);
if (ret > 0) {
if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
ret = -EINVAL;
else
ret = 0;
}
kfree(txmsg);
drm_dp_mst_topology_put_port(port);
return ret;
}
EXPORT_SYMBOL(drm_dp_send_power_updown_phy);
static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
int id,
struct drm_dp_payload *payload)
{
int ret;
ret = drm_dp_dpcd_write_payload(mgr, id, payload);
if (ret < 0) {
payload->payload_state = 0;
return ret;
}
payload->payload_state = DP_PAYLOAD_LOCAL;
return 0;
}
static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port,
int id,
struct drm_dp_payload *payload)
{
int ret;
ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
if (ret < 0)
return ret;
payload->payload_state = DP_PAYLOAD_REMOTE;
return ret;
}
static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port,
int id,
struct drm_dp_payload *payload)
{
DRM_DEBUG_KMS("\n");
/* it's okay for these to fail */
if (port) {
drm_dp_payload_send_msg(mgr, port, id, 0);
}
drm_dp_dpcd_write_payload(mgr, id, payload);
payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
return 0;
}
static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
int id,
struct drm_dp_payload *payload)
{
payload->payload_state = 0;
return 0;
}
/**
* drm_dp_update_payload_part1() - Execute payload update part 1
* @mgr: manager to use.
*
* This iterates over all proposed virtual channels, and tries to
* allocate space in the link for them. For 0->slots transitions,
* this step just writes the VCPI to the MST device. For slots->0
* transitions, this writes the updated VCPIs and removes the
* remote VC payloads.
*
* after calling this the driver should generate ACT and payload
* packets.
*/
int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
{
struct drm_dp_payload req_payload;
struct drm_dp_mst_port *port;
int i, j;
int cur_slots = 1;
mutex_lock(&mgr->payload_lock);
for (i = 0; i < mgr->max_payloads; i++) {
struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
struct drm_dp_payload *payload = &mgr->payloads[i];
bool put_port = false;
/* solve the current payloads - compare to the hw ones
- update the hw view */
req_payload.start_slot = cur_slots;
if (vcpi) {
port = container_of(vcpi, struct drm_dp_mst_port,
vcpi);
/* Validated ports don't matter if we're releasing
* VCPI
*/
if (vcpi->num_slots) {
port = drm_dp_mst_topology_get_port_validated(
mgr, port);
if (!port) {
mutex_unlock(&mgr->payload_lock);
return -EINVAL;
}
put_port = true;
}
req_payload.num_slots = vcpi->num_slots;
req_payload.vcpi = vcpi->vcpi;
} else {
port = NULL;
req_payload.num_slots = 0;
}
payload->start_slot = req_payload.start_slot;
/* work out what is required to happen with this payload */
if (payload->num_slots != req_payload.num_slots) {
/* need to push an update for this payload */
if (req_payload.num_slots) {
drm_dp_create_payload_step1(mgr, vcpi->vcpi,
&req_payload);
payload->num_slots = req_payload.num_slots;
payload->vcpi = req_payload.vcpi;
} else if (payload->num_slots) {
payload->num_slots = 0;
drm_dp_destroy_payload_step1(mgr, port,
payload->vcpi,
payload);
req_payload.payload_state =
payload->payload_state;
payload->start_slot = 0;
}
payload->payload_state = req_payload.payload_state;
}
cur_slots += req_payload.num_slots;
if (put_port)
drm_dp_mst_topology_put_port(port);
}
for (i = 0; i < mgr->max_payloads; i++) {
if (mgr->payloads[i].payload_state != DP_PAYLOAD_DELETE_LOCAL)
continue;
DRM_DEBUG_KMS("removing payload %d\n", i);
for (j = i; j < mgr->max_payloads - 1; j++) {
mgr->payloads[j] = mgr->payloads[j + 1];
mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
if (mgr->proposed_vcpis[j] &&
mgr->proposed_vcpis[j]->num_slots) {
set_bit(j + 1, &mgr->payload_mask);
} else {
clear_bit(j + 1, &mgr->payload_mask);
}
}
memset(&mgr->payloads[mgr->max_payloads - 1], 0,
sizeof(struct drm_dp_payload));
mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
clear_bit(mgr->max_payloads, &mgr->payload_mask);
}
mutex_unlock(&mgr->payload_lock);
return 0;
}
EXPORT_SYMBOL(drm_dp_update_payload_part1);
/**
* drm_dp_update_payload_part2() - Execute payload update part 2
* @mgr: manager to use.
*
* This iterates over all proposed virtual channels, and tries to
* allocate space in the link for them. For 0->slots transitions,
* this step writes the remote VC payload commands. For slots->0
* this just resets some internal state.
*/
int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
{
struct drm_dp_mst_port *port;
int i;
int ret = 0;
mutex_lock(&mgr->payload_lock);
for (i = 0; i < mgr->max_payloads; i++) {
if (!mgr->proposed_vcpis[i])
continue;
port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
} else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
}
if (ret) {
mutex_unlock(&mgr->payload_lock);
return ret;
}
}
mutex_unlock(&mgr->payload_lock);
return 0;
}
EXPORT_SYMBOL(drm_dp_update_payload_part2);
static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port,
int offset, int size, u8 *bytes)
{
int len;
int ret = 0;
struct drm_dp_sideband_msg_tx *txmsg;
struct drm_dp_mst_branch *mstb;
mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
if (!mstb)
return -EINVAL;
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg) {
ret = -ENOMEM;
goto fail_put;
}
len = build_dpcd_read(txmsg, port->port_num, offset, size);
txmsg->dst = port->parent;
drm_dp_queue_down_tx(mgr, txmsg);
ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
if (ret < 0)
goto fail_free;
/* DPCD read should never be NACKed */
if (txmsg->reply.reply_type == 1) {
DRM_ERROR("mstb %p port %d: DPCD read on addr 0x%x for %d bytes NAKed\n",
mstb, port->port_num, offset, size);
ret = -EIO;
goto fail_free;
}
if (txmsg->reply.u.remote_dpcd_read_ack.num_bytes != size) {
ret = -EPROTO;
goto fail_free;
}
ret = min_t(size_t, txmsg->reply.u.remote_dpcd_read_ack.num_bytes,
size);
memcpy(bytes, txmsg->reply.u.remote_dpcd_read_ack.bytes, ret);
fail_free:
kfree(txmsg);
fail_put:
drm_dp_mst_topology_put_mstb(mstb);
return ret;
}
static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port,
int offset, int size, u8 *bytes)
{
int len;
int ret;
struct drm_dp_sideband_msg_tx *txmsg;
struct drm_dp_mst_branch *mstb;
mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
if (!mstb)
return -EINVAL;
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg) {
ret = -ENOMEM;
goto fail_put;
}
len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
txmsg->dst = mstb;
drm_dp_queue_down_tx(mgr, txmsg);
ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
if (ret > 0) {
if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
ret = -EIO;
else
ret = 0;
}
kfree(txmsg);
fail_put:
drm_dp_mst_topology_put_mstb(mstb);
return ret;
}
static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
{
struct drm_dp_sideband_msg_reply_body reply;
reply.reply_type = DP_SIDEBAND_REPLY_ACK;
reply.req_type = req_type;
drm_dp_encode_sideband_reply(&reply, msg);
return 0;
}
static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb,
int req_type, int seqno, bool broadcast)
{
struct drm_dp_sideband_msg_tx *txmsg;
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg)
return -ENOMEM;
txmsg->dst = mstb;
txmsg->seqno = seqno;
drm_dp_encode_up_ack_reply(txmsg, req_type);
mutex_lock(&mgr->qlock);
process_single_up_tx_qlock(mgr, txmsg);
mutex_unlock(&mgr->qlock);
kfree(txmsg);
return 0;
}
static int drm_dp_get_vc_payload_bw(u8 dp_link_bw, u8 dp_link_count)
{
if (dp_link_bw == 0 || dp_link_count == 0)
DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
dp_link_bw, dp_link_count);
return dp_link_bw * dp_link_count / 2;
}
/**
* drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
* @mgr: manager to set state for
* @mst_state: true to enable MST on this connector - false to disable.
*
* This is called by the driver when it detects an MST capable device plugged
* into a DP MST capable port, or when a DP MST capable device is unplugged.
*/
int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
{
int ret = 0;
int i = 0;
struct drm_dp_mst_branch *mstb = NULL;
mutex_lock(&mgr->lock);
if (mst_state == mgr->mst_state)
goto out_unlock;
mgr->mst_state = mst_state;
/* set the device into MST mode */
if (mst_state) {
WARN_ON(mgr->mst_primary);
/* get dpcd info */
ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
if (ret != DP_RECEIVER_CAP_SIZE) {
DRM_DEBUG_KMS("failed to read DPCD\n");
goto out_unlock;
}
mgr->pbn_div = drm_dp_get_vc_payload_bw(mgr->dpcd[1],
mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK);
if (mgr->pbn_div == 0) {
ret = -EINVAL;
goto out_unlock;
}
/* add initial branch device at LCT 1 */
mstb = drm_dp_add_mst_branch_device(1, NULL);
if (mstb == NULL) {
ret = -ENOMEM;
goto out_unlock;
}
mstb->mgr = mgr;
/* give this the main reference */
mgr->mst_primary = mstb;
drm_dp_mst_topology_get_mstb(mgr->mst_primary);
ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
if (ret < 0) {
goto out_unlock;
}
{
struct drm_dp_payload reset_pay;
reset_pay.start_slot = 0;
reset_pay.num_slots = 0x3f;
drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
}
queue_work(system_long_wq, &mgr->work);
ret = 0;
} else {
/* disable MST on the device */
mstb = mgr->mst_primary;
mgr->mst_primary = NULL;
/* this can fail if the device is gone */
drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
ret = 0;
mutex_lock(&mgr->payload_lock);
memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
mgr->payload_mask = 0;
set_bit(0, &mgr->payload_mask);
for (i = 0; i < mgr->max_payloads; i++) {
struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
if (vcpi) {
vcpi->vcpi = 0;
vcpi->num_slots = 0;
}
mgr->proposed_vcpis[i] = NULL;
}
mgr->vcpi_mask = 0;
mutex_unlock(&mgr->payload_lock);
mgr->payload_id_table_cleared = false;
}
out_unlock:
mutex_unlock(&mgr->lock);
if (mstb)
drm_dp_mst_topology_put_mstb(mstb);
return ret;
}
EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
/**
* drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
* @mgr: manager to suspend
*
* This function tells the MST device that we can't handle UP messages
* anymore. This should stop it from sending any since we are suspended.
*/
void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
{
mutex_lock(&mgr->lock);
drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
DP_MST_EN | DP_UPSTREAM_IS_SRC);
mutex_unlock(&mgr->lock);
flush_work(&mgr->work);
flush_work(&mgr->destroy_connector_work);
}
EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
/**
* drm_dp_mst_topology_mgr_resume() - resume the MST manager
* @mgr: manager to resume
*
* This will fetch DPCD and see if the device is still there,
* if it is, it will rewrite the MSTM control bits, and return.
*
* if the device fails this returns -1, and the driver should do
* a full MST reprobe, in case we were undocked.
*/
int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
{
int ret = 0;
mutex_lock(&mgr->lock);
if (mgr->mst_primary) {
int sret;
u8 guid[16];
sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
if (sret != DP_RECEIVER_CAP_SIZE) {
DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
ret = -1;
goto out_unlock;
}
ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
if (ret < 0) {
DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
ret = -1;
goto out_unlock;
}
/* Some hubs forget their guids after they resume */
sret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
if (sret != 16) {
DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
ret = -1;
goto out_unlock;
}
drm_dp_check_mstb_guid(mgr->mst_primary, guid);
ret = 0;
} else
ret = -1;
out_unlock:
mutex_unlock(&mgr->lock);
return ret;
}
EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
static bool drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
{
int len;
u8 replyblock[32];
int replylen, origlen, curreply;
int ret;
struct drm_dp_sideband_msg_rx *msg;
int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
len = min(mgr->max_dpcd_transaction_bytes, 16);
ret = drm_dp_dpcd_read(mgr->aux, basereg,
replyblock, len);
if (ret != len) {
DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
return false;
}
ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
if (!ret) {
DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
return false;
}
replylen = msg->curchunk_len + msg->curchunk_hdrlen;
origlen = replylen;
replylen -= len;
curreply = len;
while (replylen > 0) {
len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
replyblock, len);
if (ret != len) {
DRM_DEBUG_KMS("failed to read a chunk (len %d, ret %d)\n",
len, ret);
return false;
}
ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
if (!ret) {
DRM_DEBUG_KMS("failed to build sideband msg\n");
return false;
}
curreply += len;
replylen -= len;
}
return true;
}
static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
{
struct drm_dp_sideband_msg_tx *txmsg;
struct drm_dp_mst_branch *mstb;
struct drm_dp_sideband_msg_hdr *hdr = &mgr->down_rep_recv.initial_hdr;
int slot = -1;
if (!drm_dp_get_one_sb_msg(mgr, false))
goto clear_down_rep_recv;
if (!mgr->down_rep_recv.have_eomt)
return 0;
mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad);
if (!mstb) {
DRM_DEBUG_KMS("Got MST reply from unknown device %d\n",
hdr->lct);
goto clear_down_rep_recv;
}
/* find the message */
slot = hdr->seqno;
mutex_lock(&mgr->qlock);
txmsg = mstb->tx_slots[slot];
/* remove from slots */
mutex_unlock(&mgr->qlock);
if (!txmsg) {
DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
mstb, hdr->seqno, hdr->lct, hdr->rad[0],
mgr->down_rep_recv.msg[0]);
goto no_msg;
}
drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
DRM_DEBUG_KMS("Got NAK reply: req 0x%02x (%s), reason 0x%02x (%s), nak data 0x%02x\n",
txmsg->reply.req_type,
drm_dp_mst_req_type_str(txmsg->reply.req_type),
txmsg->reply.u.nak.reason,
drm_dp_mst_nak_reason_str(txmsg->reply.u.nak.reason),
txmsg->reply.u.nak.nak_data);
memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
drm_dp_mst_topology_put_mstb(mstb);
mutex_lock(&mgr->qlock);
txmsg->state = DRM_DP_SIDEBAND_TX_RX;
mstb->tx_slots[slot] = NULL;
mutex_unlock(&mgr->qlock);
wake_up_all(&mgr->tx_waitq);
return 0;
no_msg:
drm_dp_mst_topology_put_mstb(mstb);
clear_down_rep_recv:
memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
return 0;
}
static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
{
struct drm_dp_sideband_msg_req_body msg;
struct drm_dp_sideband_msg_hdr *hdr = &mgr->up_req_recv.initial_hdr;
struct drm_dp_mst_branch *mstb = NULL;
const u8 *guid;
bool seqno;
if (!drm_dp_get_one_sb_msg(mgr, true))
goto out;
if (!mgr->up_req_recv.have_eomt)
return 0;
if (!hdr->broadcast) {
mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad);
if (!mstb) {
DRM_DEBUG_KMS("Got MST reply from unknown device %d\n",
hdr->lct);
goto out;
}
}
seqno = hdr->seqno;
drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY)
guid = msg.u.conn_stat.guid;
else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY)
guid = msg.u.resource_stat.guid;
else
goto out;
drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno,
false);
if (!mstb) {
mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid);
if (!mstb) {
DRM_DEBUG_KMS("Got MST reply from unknown device %d\n",
hdr->lct);
goto out;
}
}
if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
drm_dp_mst_handle_conn_stat(mstb, &msg.u.conn_stat);
DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n",
msg.u.conn_stat.port_number,
msg.u.conn_stat.legacy_device_plug_status,
msg.u.conn_stat.displayport_device_plug_status,
msg.u.conn_stat.message_capability_status,
msg.u.conn_stat.input_port,
msg.u.conn_stat.peer_device_type);
drm_kms_helper_hotplug_event(mgr->dev);
} else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n",
msg.u.resource_stat.port_number,
msg.u.resource_stat.available_pbn);
}
drm_dp_mst_topology_put_mstb(mstb);
out:
memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
return 0;
}
/**
* drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
* @mgr: manager to notify irq for.
* @esi: 4 bytes from SINK_COUNT_ESI
* @handled: whether the hpd interrupt was consumed or not
*
* This should be called from the driver when it detects a short IRQ,
* along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
* topology manager will process the sideband messages received as a result
* of this.
*/
int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
{
int ret = 0;
int sc;
*handled = false;
sc = esi[0] & 0x3f;
if (sc != mgr->sink_count) {
mgr->sink_count = sc;
*handled = true;
}
if (esi[1] & DP_DOWN_REP_MSG_RDY) {
ret = drm_dp_mst_handle_down_rep(mgr);
*handled = true;
}
if (esi[1] & DP_UP_REQ_MSG_RDY) {
ret |= drm_dp_mst_handle_up_req(mgr);
*handled = true;
}
drm_dp_mst_kick_tx(mgr);
return ret;
}
EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
/**
* drm_dp_mst_detect_port() - get connection status for an MST port
* @connector: DRM connector for this port
* @mgr: manager for this port
* @port: unverified pointer to a port
*
* This returns the current connection state for a port. It validates the
* port pointer still exists so the caller doesn't require a reference
*/
enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
{
enum drm_connector_status status = connector_status_disconnected;
/* we need to search for the port in the mgr in case it's gone */
port = drm_dp_mst_topology_get_port_validated(mgr, port);
if (!port)
return connector_status_disconnected;
if (!port->ddps)
goto out;
switch (port->pdt) {
case DP_PEER_DEVICE_NONE:
case DP_PEER_DEVICE_MST_BRANCHING:
break;
case DP_PEER_DEVICE_SST_SINK:
status = connector_status_connected;
/* for logical ports - cache the EDID */
if (port->port_num >= 8 && !port->cached_edid) {
port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
}
break;
case DP_PEER_DEVICE_DP_LEGACY_CONV:
if (port->ldps)
status = connector_status_connected;
break;
}
out:
drm_dp_mst_topology_put_port(port);
return status;
}
EXPORT_SYMBOL(drm_dp_mst_detect_port);
/**
* drm_dp_mst_port_has_audio() - Check whether port has audio capability or not
* @mgr: manager for this port
* @port: unverified pointer to a port.
*
* This returns whether the port supports audio or not.
*/
bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port)
{
bool ret = false;
port = drm_dp_mst_topology_get_port_validated(mgr, port);
if (!port)
return ret;
ret = port->has_audio;
drm_dp_mst_topology_put_port(port);
return ret;
}
EXPORT_SYMBOL(drm_dp_mst_port_has_audio);
/**
* drm_dp_mst_get_edid() - get EDID for an MST port
* @connector: toplevel connector to get EDID for
* @mgr: manager for this port
* @port: unverified pointer to a port.
*
* This returns an EDID for the port connected to a connector,
* It validates the pointer still exists so the caller doesn't require a
* reference.
*/
struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
{
struct edid *edid = NULL;
/* we need to search for the port in the mgr in case it's gone */
port = drm_dp_mst_topology_get_port_validated(mgr, port);
if (!port)
return NULL;
if (port->cached_edid)
edid = drm_edid_duplicate(port->cached_edid);
else {
edid = drm_get_edid(connector, &port->aux.ddc);
}
port->has_audio = drm_detect_monitor_audio(edid);
drm_dp_mst_topology_put_port(port);
return edid;
}
EXPORT_SYMBOL(drm_dp_mst_get_edid);
/**
* drm_dp_find_vcpi_slots() - Find VCPI slots for this PBN value
* @mgr: manager to use
* @pbn: payload bandwidth to convert into slots.
*
* Calculate the number of VCPI slots that will be required for the given PBN
* value. This function is deprecated, and should not be used in atomic
* drivers.
*
* RETURNS:
* The total slots required for this port, or error.
*/
int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
int pbn)
{
int num_slots;
num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
/* max. time slots - one slot for MTP header */
if (num_slots > 63)
return -ENOSPC;
return num_slots;
}
EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_vcpi *vcpi, int pbn, int slots)
{
int ret;
/* max. time slots - one slot for MTP header */
if (slots > 63)
return -ENOSPC;
vcpi->pbn = pbn;
vcpi->aligned_pbn = slots * mgr->pbn_div;
vcpi->num_slots = slots;
ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
if (ret < 0)
return ret;
return 0;
}
/**
* drm_dp_atomic_find_vcpi_slots() - Find and add VCPI slots to the state
* @state: global atomic state
* @mgr: MST topology manager for the port
* @port: port to find vcpi slots for
* @pbn: bandwidth required for the mode in PBN
*
* Allocates VCPI slots to @port, replacing any previous VCPI allocations it
* may have had. Any atomic drivers which support MST must call this function
* in their &drm_encoder_helper_funcs.atomic_check() callback to change the
* current VCPI allocation for the new state, but only when
* &drm_crtc_state.mode_changed or &drm_crtc_state.connectors_changed is set
* to ensure compatibility with userspace applications that still use the
* legacy modesetting UAPI.
*
* Allocations set by this function are not checked against the bandwidth
* restraints of @mgr until the driver calls drm_dp_mst_atomic_check().
*
* Additionally, it is OK to call this function multiple times on the same
* @port as needed. It is not OK however, to call this function and
* drm_dp_atomic_release_vcpi_slots() in the same atomic check phase.
*
* See also:
* drm_dp_atomic_release_vcpi_slots()
* drm_dp_mst_atomic_check()
*
* Returns:
* Total slots in the atomic state assigned for this port, or a negative error
* code if the port no longer exists
*/
int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port, int pbn)
{
struct drm_dp_mst_topology_state *topology_state;
struct drm_dp_vcpi_allocation *pos, *vcpi = NULL;
int prev_slots, req_slots;
topology_state = drm_atomic_get_mst_topology_state(state, mgr);
if (IS_ERR(topology_state))
return PTR_ERR(topology_state);
/* Find the current allocation for this port, if any */
list_for_each_entry(pos, &topology_state->vcpis, next) {
if (pos->port == port) {
vcpi = pos;
prev_slots = vcpi->vcpi;
/*
* This should never happen, unless the driver tries
* releasing and allocating the same VCPI allocation,
* which is an error
*/
if (WARN_ON(!prev_slots)) {
DRM_ERROR("cannot allocate and release VCPI on [MST PORT:%p] in the same state\n",
port);
return -EINVAL;
}
break;
}
}
if (!vcpi)
prev_slots = 0;
req_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] VCPI %d -> %d\n",
port->connector->base.id, port->connector->name,
port, prev_slots, req_slots);
/* Add the new allocation to the state */
if (!vcpi) {
vcpi = kzalloc(sizeof(*vcpi), GFP_KERNEL);
if (!vcpi)
return -ENOMEM;
drm_dp_mst_get_port_malloc(port);
vcpi->port = port;
list_add(&vcpi->next, &topology_state->vcpis);
}
vcpi->vcpi = req_slots;
return req_slots;
}
EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots);
/**
* drm_dp_atomic_release_vcpi_slots() - Release allocated vcpi slots
* @state: global atomic state
* @mgr: MST topology manager for the port
* @port: The port to release the VCPI slots from
*
* Releases any VCPI slots that have been allocated to a port in the atomic
* state. Any atomic drivers which support MST must call this function in
* their &drm_connector_helper_funcs.atomic_check() callback when the
* connector will no longer have VCPI allocated (e.g. because its CRTC was
* removed) when it had VCPI allocated in the previous atomic state.
*
* It is OK to call this even if @port has been removed from the system.
* Additionally, it is OK to call this function multiple times on the same
* @port as needed. It is not OK however, to call this function and
* drm_dp_atomic_find_vcpi_slots() on the same @port in a single atomic check
* phase.
*
* See also:
* drm_dp_atomic_find_vcpi_slots()
* drm_dp_mst_atomic_check()
*
* Returns:
* 0 if all slots for this port were added back to
* &drm_dp_mst_topology_state.avail_slots or negative error code
*/
int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port)
{
struct drm_dp_mst_topology_state *topology_state;
struct drm_dp_vcpi_allocation *pos;
bool found = false;
topology_state = drm_atomic_get_mst_topology_state(state, mgr);
if (IS_ERR(topology_state))
return PTR_ERR(topology_state);
list_for_each_entry(pos, &topology_state->vcpis, next) {
if (pos->port == port) {
found = true;
break;
}
}
if (WARN_ON(!found)) {
DRM_ERROR("no VCPI for [MST PORT:%p] found in mst state %p\n",
port, &topology_state->base);
return -EINVAL;
}
DRM_DEBUG_ATOMIC("[MST PORT:%p] VCPI %d -> 0\n", port, pos->vcpi);
if (pos->vcpi) {
drm_dp_mst_put_port_malloc(port);
pos->vcpi = 0;
}
return 0;
}
EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots);
/**
* drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
* @mgr: manager for this port
* @port: port to allocate a virtual channel for.
* @pbn: payload bandwidth number to request
* @slots: returned number of slots for this PBN.
*/
bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port, int pbn, int slots)
{
int ret;
port = drm_dp_mst_topology_get_port_validated(mgr, port);
if (!port)
return false;
if (slots < 0)
return false;
if (port->vcpi.vcpi > 0) {
DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n",
port->vcpi.vcpi, port->vcpi.pbn, pbn);
if (pbn == port->vcpi.pbn) {
drm_dp_mst_topology_put_port(port);
return true;
}
}
ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn, slots);
if (ret) {
DRM_DEBUG_KMS("failed to init vcpi slots=%d max=63 ret=%d\n",
DIV_ROUND_UP(pbn, mgr->pbn_div), ret);
goto out;
}
DRM_DEBUG_KMS("initing vcpi for pbn=%d slots=%d\n",
pbn, port->vcpi.num_slots);
/* Keep port allocated until its payload has been removed */
drm_dp_mst_get_port_malloc(port);
drm_dp_mst_topology_put_port(port);
return true;
out:
return false;
}
EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
{
int slots = 0;
port = drm_dp_mst_topology_get_port_validated(mgr, port);
if (!port)
return slots;
slots = port->vcpi.num_slots;
drm_dp_mst_topology_put_port(port);
return slots;
}
EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
/**
* drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
* @mgr: manager for this port
* @port: unverified pointer to a port.
*
* This just resets the number of slots for the ports VCPI for later programming.
*/
void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
{
/*
* A port with VCPI will remain allocated until its VCPI is
* released, no verified ref needed
*/
port->vcpi.num_slots = 0;
}
EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
/**
* drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
* @mgr: manager for this port
* @port: port to deallocate vcpi for
*
* This can be called unconditionally, regardless of whether
* drm_dp_mst_allocate_vcpi() succeeded or not.
*/
void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port)
{
if (!port->vcpi.vcpi)
return;
drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
port->vcpi.num_slots = 0;
port->vcpi.pbn = 0;
port->vcpi.aligned_pbn = 0;
port->vcpi.vcpi = 0;
drm_dp_mst_put_port_malloc(port);
}
EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
int id, struct drm_dp_payload *payload)
{
u8 payload_alloc[3], status;
int ret;
int retries = 0;
drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
DP_PAYLOAD_TABLE_UPDATED);
payload_alloc[0] = id;
payload_alloc[1] = payload->start_slot;
payload_alloc[2] = payload->num_slots;
ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
if (ret != 3) {
DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
goto fail;
}
retry:
ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
if (ret < 0) {
DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
goto fail;
}
if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
retries++;
if (retries < 20) {
usleep_range(10000, 20000);
goto retry;
}
DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
ret = -EINVAL;
goto fail;
}
ret = 0;
fail:
return ret;
}
/**
* drm_dp_check_act_status() - Check ACT handled status.
* @mgr: manager to use
*
* Check the payload status bits in the DPCD for ACT handled completion.
*/
int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
{
u8 status;
int ret;
int count = 0;
do {
ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
if (ret < 0) {
DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
goto fail;
}
if (status & DP_PAYLOAD_ACT_HANDLED)
break;
count++;
udelay(100);
} while (count < 30);
if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
ret = -EINVAL;
goto fail;
}
return 0;
fail:
return ret;
}
EXPORT_SYMBOL(drm_dp_check_act_status);
/**
* drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
* @clock: dot clock for the mode
* @bpp: bpp for the mode.
*
* This uses the formula in the spec to calculate the PBN value for a mode.
*/
int drm_dp_calc_pbn_mode(int clock, int bpp)
{
/*
* margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
* The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
* common multiplier to render an integer PBN for all link rate/lane
* counts combinations
* calculate
* peak_kbps *= (1006/1000)
* peak_kbps *= (64/54)
* peak_kbps *= 8 convert to bytes
*/
return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006),
8 * 54 * 1000 * 1000);
}
EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
/* we want to kick the TX after we've ack the up/down IRQs. */
static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
{
queue_work(system_long_wq, &mgr->tx_work);
}
static void drm_dp_mst_dump_mstb(struct seq_file *m,
struct drm_dp_mst_branch *mstb)
{
struct drm_dp_mst_port *port;
int tabs = mstb->lct;
char prefix[10];
int i;
for (i = 0; i < tabs; i++)
prefix[i] = '\t';
prefix[i] = '\0';
seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
list_for_each_entry(port, &mstb->ports, next) {
seq_printf(m, "%sport: %d: input: %d: pdt: %d, ddps: %d ldps: %d, sdp: %d/%d, %p, conn: %p\n", prefix, port->port_num, port->input, port->pdt, port->ddps, port->ldps, port->num_sdp_streams, port->num_sdp_stream_sinks, port, port->connector);
if (port->mstb)
drm_dp_mst_dump_mstb(m, port->mstb);
}
}
#define DP_PAYLOAD_TABLE_SIZE 64
static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
char *buf)
{
int i;
for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) {
if (drm_dp_dpcd_read(mgr->aux,
DP_PAYLOAD_TABLE_UPDATE_STATUS + i,
&buf[i], 16) != 16)
return false;
}
return true;
}
static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port, char *name,
int namelen)
{
struct edid *mst_edid;
mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port);
drm_edid_get_monitor_name(mst_edid, name, namelen);
}
/**
* drm_dp_mst_dump_topology(): dump topology to seq file.
* @m: seq_file to dump output to
* @mgr: manager to dump current topology for.
*
* helper to dump MST topology to a seq file for debugfs.
*/
void drm_dp_mst_dump_topology(struct seq_file *m,
struct drm_dp_mst_topology_mgr *mgr)
{
int i;
struct drm_dp_mst_port *port;
mutex_lock(&mgr->lock);
if (mgr->mst_primary)
drm_dp_mst_dump_mstb(m, mgr->mst_primary);
/* dump VCPIs */
mutex_unlock(&mgr->lock);
mutex_lock(&mgr->payload_lock);
seq_printf(m, "vcpi: %lx %lx %d\n", mgr->payload_mask, mgr->vcpi_mask,
mgr->max_payloads);
for (i = 0; i < mgr->max_payloads; i++) {
if (mgr->proposed_vcpis[i]) {
char name[14];
port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
fetch_monitor_name(mgr, port, name, sizeof(name));
seq_printf(m, "vcpi %d: %d %d %d sink name: %s\n", i,
port->port_num, port->vcpi.vcpi,
port->vcpi.num_slots,
(*name != 0) ? name : "Unknown");
} else
seq_printf(m, "vcpi %d:unused\n", i);
}
for (i = 0; i < mgr->max_payloads; i++) {
seq_printf(m, "payload %d: %d, %d, %d\n",
i,
mgr->payloads[i].payload_state,
mgr->payloads[i].start_slot,
mgr->payloads[i].num_slots);
}
mutex_unlock(&mgr->payload_lock);
mutex_lock(&mgr->lock);
if (mgr->mst_primary) {
u8 buf[DP_PAYLOAD_TABLE_SIZE];
int ret;
ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
seq_printf(m, "faux/mst: %*ph\n", 2, buf);
ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
/* dump the standard OUI branch header */
ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
seq_printf(m, "branch oui: %*phN devid: ", 3, buf);
for (i = 0x3; i < 0x8 && buf[i]; i++)
seq_printf(m, "%c", buf[i]);
seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n",
buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
if (dump_dp_payload_table(mgr, buf))
seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf);
}
mutex_unlock(&mgr->lock);
}
EXPORT_SYMBOL(drm_dp_mst_dump_topology);
static void drm_dp_tx_work(struct work_struct *work)
{
struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
mutex_lock(&mgr->qlock);
if (!list_empty(&mgr->tx_msg_downq))
process_single_down_tx_qlock(mgr);
mutex_unlock(&mgr->qlock);
}
static void drm_dp_destroy_connector_work(struct work_struct *work)
{
struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work);
struct drm_dp_mst_port *port;
bool send_hotplug = false;
/*
* Not a regular list traverse as we have to drop the destroy
* connector lock before destroying the connector, to avoid AB->BA
* ordering between this lock and the config mutex.
*/
for (;;) {
mutex_lock(&mgr->destroy_connector_lock);
port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next);
if (!port) {
mutex_unlock(&mgr->destroy_connector_lock);
break;
}
list_del(&port->next);
mutex_unlock(&mgr->destroy_connector_lock);
mgr->cbs->destroy_connector(mgr, port->connector);
drm_dp_port_teardown_pdt(port, port->pdt);
port->pdt = DP_PEER_DEVICE_NONE;
drm_dp_mst_put_port_malloc(port);
send_hotplug = true;
}
if (send_hotplug)
drm_kms_helper_hotplug_event(mgr->dev);
}
static struct drm_private_state *
drm_dp_mst_duplicate_state(struct drm_private_obj *obj)
{
struct drm_dp_mst_topology_state *state, *old_state =
to_dp_mst_topology_state(obj->state);
struct drm_dp_vcpi_allocation *pos, *vcpi;
state = kmemdup(old_state, sizeof(*state), GFP_KERNEL);
if (!state)
return NULL;
__drm_atomic_helper_private_obj_duplicate_state(obj, &state->base);
INIT_LIST_HEAD(&state->vcpis);
list_for_each_entry(pos, &old_state->vcpis, next) {
/* Prune leftover freed VCPI allocations */
if (!pos->vcpi)
continue;
vcpi = kmemdup(pos, sizeof(*vcpi), GFP_KERNEL);
if (!vcpi)
goto fail;
drm_dp_mst_get_port_malloc(vcpi->port);
list_add(&vcpi->next, &state->vcpis);
}
return &state->base;
fail:
list_for_each_entry_safe(pos, vcpi, &state->vcpis, next) {
drm_dp_mst_put_port_malloc(pos->port);
kfree(pos);
}
kfree(state);
return NULL;
}
static void drm_dp_mst_destroy_state(struct drm_private_obj *obj,
struct drm_private_state *state)
{
struct drm_dp_mst_topology_state *mst_state =
to_dp_mst_topology_state(state);
struct drm_dp_vcpi_allocation *pos, *tmp;
list_for_each_entry_safe(pos, tmp, &mst_state->vcpis, next) {
/* We only keep references to ports with non-zero VCPIs */
if (pos->vcpi)
drm_dp_mst_put_port_malloc(pos->port);
kfree(pos);
}
kfree(mst_state);
}
static inline int
drm_dp_mst_atomic_check_topology_state(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_topology_state *mst_state)
{
struct drm_dp_vcpi_allocation *vcpi;
int avail_slots = 63, payload_count = 0;
list_for_each_entry(vcpi, &mst_state->vcpis, next) {
/* Releasing VCPI is always OK-even if the port is gone */
if (!vcpi->vcpi) {
DRM_DEBUG_ATOMIC("[MST PORT:%p] releases all VCPI slots\n",
vcpi->port);
continue;
}
DRM_DEBUG_ATOMIC("[MST PORT:%p] requires %d vcpi slots\n",
vcpi->port, vcpi->vcpi);
avail_slots -= vcpi->vcpi;
if (avail_slots < 0) {
DRM_DEBUG_ATOMIC("[MST PORT:%p] not enough VCPI slots in mst state %p (avail=%d)\n",
vcpi->port, mst_state,
avail_slots + vcpi->vcpi);
return -ENOSPC;
}
if (++payload_count > mgr->max_payloads) {
DRM_DEBUG_ATOMIC("[MST MGR:%p] state %p has too many payloads (max=%d)\n",
mgr, mst_state, mgr->max_payloads);
return -EINVAL;
}
}
DRM_DEBUG_ATOMIC("[MST MGR:%p] mst state %p VCPI avail=%d used=%d\n",
mgr, mst_state, avail_slots,
63 - avail_slots);
return 0;
}
/**
* drm_dp_mst_atomic_check - Check that the new state of an MST topology in an
* atomic update is valid
* @state: Pointer to the new &struct drm_dp_mst_topology_state
*
* Checks the given topology state for an atomic update to ensure that it's
* valid. This includes checking whether there's enough bandwidth to support
* the new VCPI allocations in the atomic update.
*
* Any atomic drivers supporting DP MST must make sure to call this after
* checking the rest of their state in their
* &drm_mode_config_funcs.atomic_check() callback.
*
* See also:
* drm_dp_atomic_find_vcpi_slots()
* drm_dp_atomic_release_vcpi_slots()
*
* Returns:
*
* 0 if the new state is valid, negative error code otherwise.
*/
int drm_dp_mst_atomic_check(struct drm_atomic_state *state)
{
struct drm_dp_mst_topology_mgr *mgr;
struct drm_dp_mst_topology_state *mst_state;
int i, ret = 0;
for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) {
ret = drm_dp_mst_atomic_check_topology_state(mgr, mst_state);
if (ret)
break;
}
return ret;
}
EXPORT_SYMBOL(drm_dp_mst_atomic_check);
const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = {
.atomic_duplicate_state = drm_dp_mst_duplicate_state,
.atomic_destroy_state = drm_dp_mst_destroy_state,
};
EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs);
/**
* drm_atomic_get_mst_topology_state: get MST topology state
*
* @state: global atomic state
* @mgr: MST topology manager, also the private object in this case
*
* This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic
* state vtable so that the private object state returned is that of a MST
* topology object. Also, drm_atomic_get_private_obj_state() expects the caller
* to care of the locking, so warn if don't hold the connection_mutex.
*
* RETURNS:
*
* The MST topology state or error pointer.
*/
struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
struct drm_dp_mst_topology_mgr *mgr)
{
return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base));
}
EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
/**
* drm_dp_mst_topology_mgr_init - initialise a topology manager
* @mgr: manager struct to initialise
* @dev: device providing this structure - for i2c addition.
* @aux: DP helper aux channel to talk to this device
* @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
* @max_payloads: maximum number of payloads this GPU can source
* @conn_base_id: the connector object ID the MST device is connected to.
*
* Return 0 for success, or negative error code on failure
*/
int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
struct drm_device *dev, struct drm_dp_aux *aux,
int max_dpcd_transaction_bytes,
int max_payloads, int conn_base_id)
{
struct drm_dp_mst_topology_state *mst_state;
mutex_init(&mgr->lock);
mutex_init(&mgr->qlock);
mutex_init(&mgr->payload_lock);
mutex_init(&mgr->destroy_connector_lock);
INIT_LIST_HEAD(&mgr->tx_msg_downq);
INIT_LIST_HEAD(&mgr->destroy_connector_list);
INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work);
init_waitqueue_head(&mgr->tx_waitq);
mgr->dev = dev;
mgr->aux = aux;
mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
mgr->max_payloads = max_payloads;
mgr->conn_base_id = conn_base_id;
if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 ||
max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)
return -EINVAL;
mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
if (!mgr->payloads)
return -ENOMEM;
mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
if (!mgr->proposed_vcpis)
return -ENOMEM;
set_bit(0, &mgr->payload_mask);
mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL);
if (mst_state == NULL)
return -ENOMEM;
mst_state->mgr = mgr;
INIT_LIST_HEAD(&mst_state->vcpis);
drm_atomic_private_obj_init(dev, &mgr->base,
&mst_state->base,
&drm_dp_mst_topology_state_funcs);
return 0;
}
EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
/**
* drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
* @mgr: manager to destroy
*/
void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
{
drm_dp_mst_topology_mgr_set_mst(mgr, false);
flush_work(&mgr->work);
flush_work(&mgr->destroy_connector_work);
mutex_lock(&mgr->payload_lock);
kfree(mgr->payloads);
mgr->payloads = NULL;
kfree(mgr->proposed_vcpis);
mgr->proposed_vcpis = NULL;
mutex_unlock(&mgr->payload_lock);
mgr->dev = NULL;
mgr->aux = NULL;
drm_atomic_private_obj_fini(&mgr->base);
mgr->funcs = NULL;
mutex_destroy(&mgr->destroy_connector_lock);
mutex_destroy(&mgr->payload_lock);
mutex_destroy(&mgr->qlock);
mutex_destroy(&mgr->lock);
}
EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
static bool remote_i2c_read_ok(const struct i2c_msg msgs[], int num)
{
int i;
if (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)
return false;
for (i = 0; i < num - 1; i++) {
if (msgs[i].flags & I2C_M_RD ||
msgs[i].len > 0xff)
return false;
}
return msgs[num - 1].flags & I2C_M_RD &&
msgs[num - 1].len <= 0xff;
}
/* I2C device */
static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
int num)
{
struct drm_dp_aux *aux = adapter->algo_data;
struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
struct drm_dp_mst_branch *mstb;
struct drm_dp_mst_topology_mgr *mgr = port->mgr;
unsigned int i;
struct drm_dp_sideband_msg_req_body msg;
struct drm_dp_sideband_msg_tx *txmsg = NULL;
int ret;
mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
if (!mstb)
return -EREMOTEIO;
if (!remote_i2c_read_ok(msgs, num)) {
DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
ret = -EIO;
goto out;
}
memset(&msg, 0, sizeof(msg));
msg.req_type = DP_REMOTE_I2C_READ;
msg.u.i2c_read.num_transactions = num - 1;
msg.u.i2c_read.port_number = port->port_num;
for (i = 0; i < num - 1; i++) {
msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP);
}
msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg) {
ret = -ENOMEM;
goto out;
}
txmsg->dst = mstb;
drm_dp_encode_sideband_req(&msg, txmsg);
drm_dp_queue_down_tx(mgr, txmsg);
ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
if (ret > 0) {
if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
ret = -EREMOTEIO;
goto out;
}
if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
ret = -EIO;
goto out;
}
memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
ret = num;
}
out:
kfree(txmsg);
drm_dp_mst_topology_put_mstb(mstb);
return ret;
}
static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
I2C_FUNC_SMBUS_READ_BLOCK_DATA |
I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
I2C_FUNC_10BIT_ADDR;
}
static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
.functionality = drm_dp_mst_i2c_functionality,
.master_xfer = drm_dp_mst_i2c_xfer,
};
/**
* drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
* @aux: DisplayPort AUX channel
*
* Returns 0 on success or a negative error code on failure.
*/
static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
{
aux->ddc.algo = &drm_dp_mst_i2c_algo;
aux->ddc.algo_data = aux;
aux->ddc.retries = 3;
aux->ddc.class = I2C_CLASS_DDC;
aux->ddc.owner = THIS_MODULE;
aux->ddc.dev.parent = aux->dev;
aux->ddc.dev.of_node = aux->dev->of_node;
strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
sizeof(aux->ddc.name));
return i2c_add_adapter(&aux->ddc);
}
/**
* drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
* @aux: DisplayPort AUX channel
*/
static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
{
i2c_del_adapter(&aux->ddc);
}
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