linux_dsm_epyc7002/drivers/gpu/drm/msm/msm_rd.c
Rob Clark 7a93d5c38e drm/msm/gpu: add submit flag to hint which buffers should be dumped
To lower CPU  overhead, future userspace will be switching to pinning
iova and avoiding the use of relocs, and only include cmds table entries
for IB1 level cmdstream (but not IB2 or state-groups).

This leaves the kernel unsure what to dump for rd/hangrd cmdstream
dumping.  So add a MSM_SUBMIT_BO_DUMP flag so userspace can indicate
buffers that contain cmdstream (or are otherwise important to dump).

Signed-off-by: Rob Clark <robdclark@gmail.com>
2018-12-11 13:07:04 -05:00

425 lines
9.9 KiB
C

/*
* Copyright (C) 2013 Red Hat
* Author: Rob Clark <robdclark@gmail.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
/* For debugging crashes, userspace can:
*
* tail -f /sys/kernel/debug/dri/<minor>/rd > logfile.rd
*
* to log the cmdstream in a format that is understood by freedreno/cffdump
* utility. By comparing the last successfully completed fence #, to the
* cmdstream for the next fence, you can narrow down which process and submit
* caused the gpu crash/lockup.
*
* Additionally:
*
* tail -f /sys/kernel/debug/dri/<minor>/hangrd > logfile.rd
*
* will capture just the cmdstream from submits which triggered a GPU hang.
*
* This bypasses drm_debugfs_create_files() mainly because we need to use
* our own fops for a bit more control. In particular, we don't want to
* do anything if userspace doesn't have the debugfs file open.
*
* The module-param "rd_full", which defaults to false, enables snapshotting
* all (non-written) buffers in the submit, rather than just cmdstream bo's.
* This is useful to capture the contents of (for example) vbo's or textures,
* or shader programs (if not emitted inline in cmdstream).
*/
#ifdef CONFIG_DEBUG_FS
#include <linux/kfifo.h>
#include <linux/debugfs.h>
#include <linux/circ_buf.h>
#include <linux/wait.h>
#include "msm_drv.h"
#include "msm_gpu.h"
#include "msm_gem.h"
static bool rd_full = false;
MODULE_PARM_DESC(rd_full, "If true, $debugfs/.../rd will snapshot all buffer contents");
module_param_named(rd_full, rd_full, bool, 0600);
enum rd_sect_type {
RD_NONE,
RD_TEST, /* ascii text */
RD_CMD, /* ascii text */
RD_GPUADDR, /* u32 gpuaddr, u32 size */
RD_CONTEXT, /* raw dump */
RD_CMDSTREAM, /* raw dump */
RD_CMDSTREAM_ADDR, /* gpu addr of cmdstream */
RD_PARAM, /* u32 param_type, u32 param_val, u32 bitlen */
RD_FLUSH, /* empty, clear previous params */
RD_PROGRAM, /* shader program, raw dump */
RD_VERT_SHADER,
RD_FRAG_SHADER,
RD_BUFFER_CONTENTS,
RD_GPU_ID,
};
#define BUF_SZ 512 /* should be power of 2 */
/* space used: */
#define circ_count(circ) \
(CIRC_CNT((circ)->head, (circ)->tail, BUF_SZ))
#define circ_count_to_end(circ) \
(CIRC_CNT_TO_END((circ)->head, (circ)->tail, BUF_SZ))
/* space available: */
#define circ_space(circ) \
(CIRC_SPACE((circ)->head, (circ)->tail, BUF_SZ))
#define circ_space_to_end(circ) \
(CIRC_SPACE_TO_END((circ)->head, (circ)->tail, BUF_SZ))
struct msm_rd_state {
struct drm_device *dev;
bool open;
/* current submit to read out: */
struct msm_gem_submit *submit;
/* fifo access is synchronized on the producer side by
* struct_mutex held by submit code (otherwise we could
* end up w/ cmds logged in different order than they
* were executed). And read_lock synchronizes the reads
*/
struct mutex read_lock;
wait_queue_head_t fifo_event;
struct circ_buf fifo;
char buf[BUF_SZ];
};
static void rd_write(struct msm_rd_state *rd, const void *buf, int sz)
{
struct circ_buf *fifo = &rd->fifo;
const char *ptr = buf;
while (sz > 0) {
char *fptr = &fifo->buf[fifo->head];
int n;
wait_event(rd->fifo_event, circ_space(&rd->fifo) > 0);
/* Note that smp_load_acquire() is not strictly required
* as CIRC_SPACE_TO_END() does not access the tail more
* than once.
*/
n = min(sz, circ_space_to_end(&rd->fifo));
memcpy(fptr, ptr, n);
smp_store_release(&fifo->head, (fifo->head + n) & (BUF_SZ - 1));
sz -= n;
ptr += n;
wake_up_all(&rd->fifo_event);
}
}
static void rd_write_section(struct msm_rd_state *rd,
enum rd_sect_type type, const void *buf, int sz)
{
rd_write(rd, &type, 4);
rd_write(rd, &sz, 4);
rd_write(rd, buf, sz);
}
static ssize_t rd_read(struct file *file, char __user *buf,
size_t sz, loff_t *ppos)
{
struct msm_rd_state *rd = file->private_data;
struct circ_buf *fifo = &rd->fifo;
const char *fptr = &fifo->buf[fifo->tail];
int n = 0, ret = 0;
mutex_lock(&rd->read_lock);
ret = wait_event_interruptible(rd->fifo_event,
circ_count(&rd->fifo) > 0);
if (ret)
goto out;
/* Note that smp_load_acquire() is not strictly required
* as CIRC_CNT_TO_END() does not access the head more than
* once.
*/
n = min_t(int, sz, circ_count_to_end(&rd->fifo));
if (copy_to_user(buf, fptr, n)) {
ret = -EFAULT;
goto out;
}
smp_store_release(&fifo->tail, (fifo->tail + n) & (BUF_SZ - 1));
*ppos += n;
wake_up_all(&rd->fifo_event);
out:
mutex_unlock(&rd->read_lock);
if (ret)
return ret;
return n;
}
static int rd_open(struct inode *inode, struct file *file)
{
struct msm_rd_state *rd = inode->i_private;
struct drm_device *dev = rd->dev;
struct msm_drm_private *priv = dev->dev_private;
struct msm_gpu *gpu = priv->gpu;
uint64_t val;
uint32_t gpu_id;
int ret = 0;
mutex_lock(&dev->struct_mutex);
if (rd->open || !gpu) {
ret = -EBUSY;
goto out;
}
file->private_data = rd;
rd->open = true;
/* the parsing tools need to know gpu-id to know which
* register database to load.
*/
gpu->funcs->get_param(gpu, MSM_PARAM_GPU_ID, &val);
gpu_id = val;
rd_write_section(rd, RD_GPU_ID, &gpu_id, sizeof(gpu_id));
out:
mutex_unlock(&dev->struct_mutex);
return ret;
}
static int rd_release(struct inode *inode, struct file *file)
{
struct msm_rd_state *rd = inode->i_private;
rd->open = false;
return 0;
}
static const struct file_operations rd_debugfs_fops = {
.owner = THIS_MODULE,
.open = rd_open,
.read = rd_read,
.llseek = no_llseek,
.release = rd_release,
};
static void rd_cleanup(struct msm_rd_state *rd)
{
if (!rd)
return;
mutex_destroy(&rd->read_lock);
kfree(rd);
}
static struct msm_rd_state *rd_init(struct drm_minor *minor, const char *name)
{
struct msm_rd_state *rd;
struct dentry *ent;
int ret = 0;
rd = kzalloc(sizeof(*rd), GFP_KERNEL);
if (!rd)
return ERR_PTR(-ENOMEM);
rd->dev = minor->dev;
rd->fifo.buf = rd->buf;
mutex_init(&rd->read_lock);
init_waitqueue_head(&rd->fifo_event);
ent = debugfs_create_file(name, S_IFREG | S_IRUGO,
minor->debugfs_root, rd, &rd_debugfs_fops);
if (!ent) {
DRM_ERROR("Cannot create /sys/kernel/debug/dri/%pd/%s\n",
minor->debugfs_root, name);
ret = -ENOMEM;
goto fail;
}
return rd;
fail:
rd_cleanup(rd);
return ERR_PTR(ret);
}
int msm_rd_debugfs_init(struct drm_minor *minor)
{
struct msm_drm_private *priv = minor->dev->dev_private;
struct msm_rd_state *rd;
int ret;
/* only create on first minor: */
if (priv->rd)
return 0;
rd = rd_init(minor, "rd");
if (IS_ERR(rd)) {
ret = PTR_ERR(rd);
goto fail;
}
priv->rd = rd;
rd = rd_init(minor, "hangrd");
if (IS_ERR(rd)) {
ret = PTR_ERR(rd);
goto fail;
}
priv->hangrd = rd;
return 0;
fail:
msm_rd_debugfs_cleanup(priv);
return ret;
}
void msm_rd_debugfs_cleanup(struct msm_drm_private *priv)
{
rd_cleanup(priv->rd);
priv->rd = NULL;
rd_cleanup(priv->hangrd);
priv->hangrd = NULL;
}
static void snapshot_buf(struct msm_rd_state *rd,
struct msm_gem_submit *submit, int idx,
uint64_t iova, uint32_t size)
{
struct msm_gem_object *obj = submit->bos[idx].obj;
const char *buf;
if (iova) {
buf += iova - submit->bos[idx].iova;
} else {
iova = submit->bos[idx].iova;
size = obj->base.size;
}
/*
* Always write the GPUADDR header so can get a complete list of all the
* buffers in the cmd
*/
rd_write_section(rd, RD_GPUADDR,
(uint32_t[3]){ iova, size, iova >> 32 }, 12);
/* But only dump the contents of buffers marked READ */
if (!(submit->bos[idx].flags & MSM_SUBMIT_BO_READ))
return;
buf = msm_gem_get_vaddr_active(&obj->base);
if (IS_ERR(buf))
return;
rd_write_section(rd, RD_BUFFER_CONTENTS, buf, size);
msm_gem_put_vaddr(&obj->base);
}
static bool
should_dump(struct msm_gem_submit *submit, int idx)
{
return rd_full || (submit->bos[idx].flags & MSM_SUBMIT_BO_DUMP);
}
/* called under struct_mutex */
void msm_rd_dump_submit(struct msm_rd_state *rd, struct msm_gem_submit *submit,
const char *fmt, ...)
{
struct drm_device *dev = submit->dev;
struct task_struct *task;
char msg[256];
int i, n;
if (!rd->open)
return;
/* writing into fifo is serialized by caller, and
* rd->read_lock is used to serialize the reads
*/
WARN_ON(!mutex_is_locked(&dev->struct_mutex));
if (fmt) {
va_list args;
va_start(args, fmt);
n = vscnprintf(msg, sizeof(msg), fmt, args);
va_end(args);
rd_write_section(rd, RD_CMD, msg, ALIGN(n, 4));
}
rcu_read_lock();
task = pid_task(submit->pid, PIDTYPE_PID);
if (task) {
n = scnprintf(msg, sizeof(msg), "%.*s/%d: fence=%u",
TASK_COMM_LEN, task->comm,
pid_nr(submit->pid), submit->seqno);
} else {
n = scnprintf(msg, sizeof(msg), "???/%d: fence=%u",
pid_nr(submit->pid), submit->seqno);
}
rcu_read_unlock();
rd_write_section(rd, RD_CMD, msg, ALIGN(n, 4));
for (i = 0; i < submit->nr_bos; i++)
if (should_dump(submit, i))
snapshot_buf(rd, submit, i, 0, 0);
for (i = 0; i < submit->nr_cmds; i++) {
uint64_t iova = submit->cmd[i].iova;
uint32_t szd = submit->cmd[i].size; /* in dwords */
/* snapshot cmdstream bo's (if we haven't already): */
if (!should_dump(submit, i)) {
snapshot_buf(rd, submit, submit->cmd[i].idx,
submit->cmd[i].iova, szd * 4);
}
switch (submit->cmd[i].type) {
case MSM_SUBMIT_CMD_IB_TARGET_BUF:
/* ignore IB-targets, we've logged the buffer, the
* parser tool will follow the IB based on the logged
* buffer/gpuaddr, so nothing more to do.
*/
break;
case MSM_SUBMIT_CMD_CTX_RESTORE_BUF:
case MSM_SUBMIT_CMD_BUF:
rd_write_section(rd, RD_CMDSTREAM_ADDR,
(uint32_t[3]){ iova, szd, iova >> 32 }, 12);
break;
}
}
}
#endif