linux_dsm_epyc7002/drivers/gpu/drm/i915/intel_atomic.c
Maarten Lankhorst d2944cf213 drm/i915: Commit planes on each crtc separately.
This patch is based on the upstream commit 5ac1c4bcf0 and amended
for v4.2 to make sure it works as intended.

Repeated calls to begin_crtc_commit can cause warnings like this:
[  169.127746] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:616
[  169.127835] in_atomic(): 0, irqs_disabled(): 1, pid: 1947, name: kms_flip
[  169.127840] 3 locks held by kms_flip/1947:
[  169.127843]  #0:  (&dev->mode_config.mutex){+.+.+.}, at: [<ffffffff814774bc>] __drm_modeset_lock_all+0x9c/0x130
[  169.127860]  #1:  (crtc_ww_class_acquire){+.+.+.}, at: [<ffffffff814774cd>] __drm_modeset_lock_all+0xad/0x130
[  169.127870]  #2:  (crtc_ww_class_mutex){+.+.+.}, at: [<ffffffff81477178>] drm_modeset_lock+0x38/0x110
[  169.127879] irq event stamp: 665690
[  169.127882] hardirqs last  enabled at (665689): [<ffffffff817ffdb5>] _raw_spin_unlock_irqrestore+0x55/0x70
[  169.127889] hardirqs last disabled at (665690): [<ffffffffc0197a23>] intel_pipe_update_start+0x113/0x5c0 [i915]
[  169.127936] softirqs last  enabled at (665470): [<ffffffff8108a766>] __do_softirq+0x236/0x650
[  169.127942] softirqs last disabled at (665465): [<ffffffff8108ae75>] irq_exit+0xc5/0xd0
[  169.127951] CPU: 1 PID: 1947 Comm: kms_flip Not tainted 4.1.0-rc4-patser+ #4039
[  169.127954] Hardware name: LENOVO 2349AV8/2349AV8, BIOS G1ETA5WW (2.65 ) 04/15/2014
[  169.127957]  ffff8800c49036f0 ffff8800cde5fa28 ffffffff817f6907 0000000080000001
[  169.127964]  0000000000000000 ffff8800cde5fa58 ffffffff810aebed 0000000000000046
[  169.127970]  ffffffff81c5d518 0000000000000268 0000000000000000 ffff8800cde5fa88
[  169.127981] Call Trace:
[  169.127992]  [<ffffffff817f6907>] dump_stack+0x4f/0x7b
[  169.128001]  [<ffffffff810aebed>] ___might_sleep+0x16d/0x270
[  169.128008]  [<ffffffff810aed38>] __might_sleep+0x48/0x90
[  169.128017]  [<ffffffff817fc359>] mutex_lock_nested+0x29/0x410
[  169.128073]  [<ffffffffc01635f0>] ? vgpu_write64+0x220/0x220 [i915]
[  169.128138]  [<ffffffffc017fddf>] ? ironlake_update_primary_plane+0x2ff/0x410 [i915]
[  169.128198]  [<ffffffffc0190e75>] intel_frontbuffer_flush+0x25/0x70 [i915]
[  169.128253]  [<ffffffffc01831ac>] intel_finish_crtc_commit+0x4c/0x180 [i915]
[  169.128279]  [<ffffffffc00784ac>] drm_atomic_helper_commit_planes+0x12c/0x240 [drm_kms_helper]
[  169.128338]  [<ffffffffc0184264>] __intel_set_mode+0x684/0x830 [i915]
[  169.128378]  [<ffffffffc018a84a>] intel_crtc_set_config+0x49a/0x620 [i915]
[  169.128385]  [<ffffffff817fdd39>] ? mutex_unlock+0x9/0x10
[  169.128391]  [<ffffffff81467b69>] drm_mode_set_config_internal+0x69/0x120
[  169.128398]  [<ffffffff8119b547>] ? might_fault+0x57/0xb0
[  169.128403]  [<ffffffff8146bf93>] drm_mode_setcrtc+0x253/0x620
[  169.128409]  [<ffffffff8145c600>] drm_ioctl+0x1a0/0x6a0
[  169.128415]  [<ffffffff810b3b41>] ? get_parent_ip+0x11/0x50
[  169.128424]  [<ffffffff811e9ab8>] do_vfs_ioctl+0x2f8/0x530
[  169.128429]  [<ffffffff810d0fcd>] ? trace_hardirqs_on+0xd/0x10
[  169.128435]  [<ffffffff812e7676>] ? selinux_file_ioctl+0x56/0x100
[  169.128439]  [<ffffffff811e9d71>] SyS_ioctl+0x81/0xa0
[  169.128445]  [<ffffffff81800697>] system_call_fastpath+0x12/0x6f

Solve it by using the newly introduced drm_atomic_helper_commit_planes_on_crtc.

The problem here was that the drm_atomic_helper_commit_planes() helper
we were using was basically designed to do

    begin_crtc_commit(crtc #1)
    begin_crtc_commit(crtc #2)
    ...
    commit all planes
    finish_crtc_commit(crtc #1)
    finish_crtc_commit(crtc #2)

The problem here is that since our hardware relies on vblank evasion,
our CRTC 'begin' function waits until we're out of the danger zone in
which register writes might wind up straddling the vblank, then disables
interrupts; our 'finish' function re-enables interrupts after the
registers have been written.  The expectation is that the operations between
'begin' and 'end' must be performed without sleeping (since interrupts
are disabled) and should happen as quickly as possible.  By clumping all
of the 'begin' calls together, we introducing a couple problems:
 * Subsequent 'begin' invocations might sleep (which is illegal)
 * The first 'begin' ensured that we were far enough from the vblank that
   we could write our registers safely and ensure they all fell within
   the same frame.  Adding extra delay waiting for subsequent CRTC's
   wasn't accounted for and could put us back into the 'danger zone' for
   CRTC #1.

This commit solves the problem by using a new helper that allows an
order of operations like:

   for each crtc {
        begin_crtc_commit(crtc)  // sleep (maybe), then disable interrupts
        commit planes for this specific CRTC
        end_crtc_commit(crtc)    // reenable interrupts
   }

so that sleeps will only be performed while interrupts are enabled and
we can be sure that registers for a CRTC will be written immediately
once we know we're in the safe zone.

The crtc->config->base.crtc update may seem unrelated, but the helper
will use it to obtain the crtc for the state. Without the update it
will dereference NULL and crash.

Changes since v1:
- Use Matt Roper's commit message.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
References: https://bugs.freedesktop.org/show_bug.cgi?id=90398
Reviewed-by: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2015-08-13 12:09:18 +03:00

321 lines
9.5 KiB
C

/*
* Copyright © 2015 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
/**
* DOC: atomic modeset support
*
* The functions here implement the state management and hardware programming
* dispatch required by the atomic modeset infrastructure.
* See intel_atomic_plane.c for the plane-specific atomic functionality.
*/
#include <drm/drmP.h>
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_plane_helper.h>
#include "intel_drv.h"
/**
* intel_connector_atomic_get_property - fetch connector property value
* @connector: connector to fetch property for
* @state: state containing the property value
* @property: property to look up
* @val: pointer to write property value into
*
* The DRM core does not store shadow copies of properties for
* atomic-capable drivers. This entrypoint is used to fetch
* the current value of a driver-specific connector property.
*/
int
intel_connector_atomic_get_property(struct drm_connector *connector,
const struct drm_connector_state *state,
struct drm_property *property,
uint64_t *val)
{
int i;
/*
* TODO: We only have atomic modeset for planes at the moment, so the
* crtc/connector code isn't quite ready yet. Until it's ready,
* continue to look up all property values in the DRM's shadow copy
* in obj->properties->values[].
*
* When the crtc/connector state work matures, this function should
* be updated to read the values out of the state structure instead.
*/
for (i = 0; i < connector->base.properties->count; i++) {
if (connector->base.properties->properties[i] == property) {
*val = connector->base.properties->values[i];
return 0;
}
}
return -EINVAL;
}
/*
* intel_crtc_duplicate_state - duplicate crtc state
* @crtc: drm crtc
*
* Allocates and returns a copy of the crtc state (both common and
* Intel-specific) for the specified crtc.
*
* Returns: The newly allocated crtc state, or NULL on failure.
*/
struct drm_crtc_state *
intel_crtc_duplicate_state(struct drm_crtc *crtc)
{
struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
struct intel_crtc_state *crtc_state;
if (WARN_ON(!intel_crtc->config))
crtc_state = kzalloc(sizeof(*crtc_state), GFP_KERNEL);
else
crtc_state = kmemdup(intel_crtc->config,
sizeof(*intel_crtc->config), GFP_KERNEL);
if (!crtc_state)
return NULL;
__drm_atomic_helper_crtc_duplicate_state(crtc, &crtc_state->base);
crtc_state->base.crtc = crtc;
return &crtc_state->base;
}
/**
* intel_crtc_destroy_state - destroy crtc state
* @crtc: drm crtc
*
* Destroys the crtc state (both common and Intel-specific) for the
* specified crtc.
*/
void
intel_crtc_destroy_state(struct drm_crtc *crtc,
struct drm_crtc_state *state)
{
drm_atomic_helper_crtc_destroy_state(crtc, state);
}
/**
* intel_atomic_setup_scalers() - setup scalers for crtc per staged requests
* @dev: DRM device
* @crtc: intel crtc
* @crtc_state: incoming crtc_state to validate and setup scalers
*
* This function sets up scalers based on staged scaling requests for
* a @crtc and its planes. It is called from crtc level check path. If request
* is a supportable request, it attaches scalers to requested planes and crtc.
*
* This function takes into account the current scaler(s) in use by any planes
* not being part of this atomic state
*
* Returns:
* 0 - scalers were setup succesfully
* error code - otherwise
*/
int intel_atomic_setup_scalers(struct drm_device *dev,
struct intel_crtc *intel_crtc,
struct intel_crtc_state *crtc_state)
{
struct drm_plane *plane = NULL;
struct intel_plane *intel_plane;
struct intel_plane_state *plane_state = NULL;
struct intel_crtc_scaler_state *scaler_state =
&crtc_state->scaler_state;
struct drm_atomic_state *drm_state = crtc_state->base.state;
int num_scalers_need;
int i, j;
num_scalers_need = hweight32(scaler_state->scaler_users);
DRM_DEBUG_KMS("crtc_state = %p need = %d avail = %d scaler_users = 0x%x\n",
crtc_state, num_scalers_need, intel_crtc->num_scalers,
scaler_state->scaler_users);
/*
* High level flow:
* - staged scaler requests are already in scaler_state->scaler_users
* - check whether staged scaling requests can be supported
* - add planes using scalers that aren't in current transaction
* - assign scalers to requested users
* - as part of plane commit, scalers will be committed
* (i.e., either attached or detached) to respective planes in hw
* - as part of crtc_commit, scaler will be either attached or detached
* to crtc in hw
*/
/* fail if required scalers > available scalers */
if (num_scalers_need > intel_crtc->num_scalers){
DRM_DEBUG_KMS("Too many scaling requests %d > %d\n",
num_scalers_need, intel_crtc->num_scalers);
return -EINVAL;
}
/* walkthrough scaler_users bits and start assigning scalers */
for (i = 0; i < sizeof(scaler_state->scaler_users) * 8; i++) {
int *scaler_id;
const char *name;
int idx;
/* skip if scaler not required */
if (!(scaler_state->scaler_users & (1 << i)))
continue;
if (i == SKL_CRTC_INDEX) {
name = "CRTC";
idx = intel_crtc->base.base.id;
/* panel fitter case: assign as a crtc scaler */
scaler_id = &scaler_state->scaler_id;
} else {
name = "PLANE";
/* plane scaler case: assign as a plane scaler */
/* find the plane that set the bit as scaler_user */
plane = drm_state->planes[i];
/*
* to enable/disable hq mode, add planes that are using scaler
* into this transaction
*/
if (!plane) {
struct drm_plane_state *state;
plane = drm_plane_from_index(dev, i);
state = drm_atomic_get_plane_state(drm_state, plane);
if (IS_ERR(state)) {
DRM_DEBUG_KMS("Failed to add [PLANE:%d] to drm_state\n",
plane->base.id);
return PTR_ERR(state);
}
/*
* the plane is added after plane checks are run,
* but since this plane is unchanged just do the
* minimum required validation.
*/
if (plane->type == DRM_PLANE_TYPE_PRIMARY)
intel_crtc->atomic.wait_for_flips = true;
crtc_state->base.planes_changed = true;
}
intel_plane = to_intel_plane(plane);
idx = plane->base.id;
/* plane on different crtc cannot be a scaler user of this crtc */
if (WARN_ON(intel_plane->pipe != intel_crtc->pipe)) {
continue;
}
plane_state = to_intel_plane_state(drm_state->plane_states[i]);
scaler_id = &plane_state->scaler_id;
}
if (*scaler_id < 0) {
/* find a free scaler */
for (j = 0; j < intel_crtc->num_scalers; j++) {
if (!scaler_state->scalers[j].in_use) {
scaler_state->scalers[j].in_use = 1;
*scaler_id = j;
DRM_DEBUG_KMS("Attached scaler id %u.%u to %s:%d\n",
intel_crtc->pipe, *scaler_id, name, idx);
break;
}
}
}
if (WARN_ON(*scaler_id < 0)) {
DRM_DEBUG_KMS("Cannot find scaler for %s:%d\n", name, idx);
continue;
}
/* set scaler mode */
if (num_scalers_need == 1 && intel_crtc->pipe != PIPE_C) {
/*
* when only 1 scaler is in use on either pipe A or B,
* scaler 0 operates in high quality (HQ) mode.
* In this case use scaler 0 to take advantage of HQ mode
*/
*scaler_id = 0;
scaler_state->scalers[0].in_use = 1;
scaler_state->scalers[0].mode = PS_SCALER_MODE_HQ;
scaler_state->scalers[1].in_use = 0;
} else {
scaler_state->scalers[*scaler_id].mode = PS_SCALER_MODE_DYN;
}
}
return 0;
}
static void
intel_atomic_duplicate_dpll_state(struct drm_i915_private *dev_priv,
struct intel_shared_dpll_config *shared_dpll)
{
enum intel_dpll_id i;
/* Copy shared dpll state */
for (i = 0; i < dev_priv->num_shared_dpll; i++) {
struct intel_shared_dpll *pll = &dev_priv->shared_dplls[i];
shared_dpll[i] = pll->config;
}
}
struct intel_shared_dpll_config *
intel_atomic_get_shared_dpll_state(struct drm_atomic_state *s)
{
struct intel_atomic_state *state = to_intel_atomic_state(s);
WARN_ON(!drm_modeset_is_locked(&s->dev->mode_config.connection_mutex));
if (!state->dpll_set) {
state->dpll_set = true;
intel_atomic_duplicate_dpll_state(to_i915(s->dev),
state->shared_dpll);
}
return state->shared_dpll;
}
struct drm_atomic_state *
intel_atomic_state_alloc(struct drm_device *dev)
{
struct intel_atomic_state *state = kzalloc(sizeof(*state), GFP_KERNEL);
if (!state || drm_atomic_state_init(dev, &state->base) < 0) {
kfree(state);
return NULL;
}
return &state->base;
}
void intel_atomic_state_clear(struct drm_atomic_state *s)
{
struct intel_atomic_state *state = to_intel_atomic_state(s);
drm_atomic_state_default_clear(&state->base);
state->dpll_set = false;
}