linux/drivers/gpu/drm/msm/msm_perf.c
Rob Clark 70c70f091b drm/msm: add perf logging debugfs
Signed-off-by: Rob Clark <robdclark@gmail.com>
2014-06-02 07:36:21 -04:00

276 lines
5.8 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 profiling, userspace can:
*
* tail -f /sys/kernel/debug/dri/<minor>/gpu
*
* This will enable performance counters/profiling to track the busy time
* and any gpu specific performance counters that are supported.
*/
#ifdef CONFIG_DEBUG_FS
#include <linux/debugfs.h>
#include "msm_drv.h"
#include "msm_gpu.h"
struct msm_perf_state {
struct drm_device *dev;
bool open;
int cnt;
struct mutex read_lock;
char buf[256];
int buftot, bufpos;
unsigned long next_jiffies;
struct dentry *ent;
struct drm_info_node *node;
};
#define SAMPLE_TIME (HZ/4)
/* wait for next sample time: */
static int wait_sample(struct msm_perf_state *perf)
{
unsigned long start_jiffies = jiffies;
if (time_after(perf->next_jiffies, start_jiffies)) {
unsigned long remaining_jiffies =
perf->next_jiffies - start_jiffies;
int ret = schedule_timeout_interruptible(remaining_jiffies);
if (ret > 0) {
/* interrupted */
return -ERESTARTSYS;
}
}
perf->next_jiffies += SAMPLE_TIME;
return 0;
}
static int refill_buf(struct msm_perf_state *perf)
{
struct msm_drm_private *priv = perf->dev->dev_private;
struct msm_gpu *gpu = priv->gpu;
char *ptr = perf->buf;
int rem = sizeof(perf->buf);
int i, n;
if ((perf->cnt++ % 32) == 0) {
/* Header line: */
n = snprintf(ptr, rem, "%%BUSY");
ptr += n;
rem -= n;
for (i = 0; i < gpu->num_perfcntrs; i++) {
const struct msm_gpu_perfcntr *perfcntr = &gpu->perfcntrs[i];
n = snprintf(ptr, rem, "\t%s", perfcntr->name);
ptr += n;
rem -= n;
}
} else {
/* Sample line: */
uint32_t activetime = 0, totaltime = 0;
uint32_t cntrs[5];
uint32_t val;
int ret;
/* sleep until next sample time: */
ret = wait_sample(perf);
if (ret)
return ret;
ret = msm_gpu_perfcntr_sample(gpu, &activetime, &totaltime,
ARRAY_SIZE(cntrs), cntrs);
if (ret < 0)
return ret;
val = totaltime ? 1000 * activetime / totaltime : 0;
n = snprintf(ptr, rem, "%3d.%d%%", val / 10, val % 10);
ptr += n;
rem -= n;
for (i = 0; i < ret; i++) {
/* cycle counters (I think).. convert to MHz.. */
val = cntrs[i] / 10000;
n = snprintf(ptr, rem, "\t%5d.%02d",
val / 100, val % 100);
ptr += n;
rem -= n;
}
}
n = snprintf(ptr, rem, "\n");
ptr += n;
rem -= n;
perf->bufpos = 0;
perf->buftot = ptr - perf->buf;
return 0;
}
static ssize_t perf_read(struct file *file, char __user *buf,
size_t sz, loff_t *ppos)
{
struct msm_perf_state *perf = file->private_data;
int n = 0, ret;
mutex_lock(&perf->read_lock);
if (perf->bufpos >= perf->buftot) {
ret = refill_buf(perf);
if (ret)
goto out;
}
n = min((int)sz, perf->buftot - perf->bufpos);
ret = copy_to_user(buf, &perf->buf[perf->bufpos], n);
if (ret)
goto out;
perf->bufpos += n;
*ppos += n;
out:
mutex_unlock(&perf->read_lock);
if (ret)
return ret;
return n;
}
static int perf_open(struct inode *inode, struct file *file)
{
struct msm_perf_state *perf = inode->i_private;
struct drm_device *dev = perf->dev;
struct msm_drm_private *priv = dev->dev_private;
struct msm_gpu *gpu = priv->gpu;
int ret = 0;
mutex_lock(&dev->struct_mutex);
if (perf->open || !gpu) {
ret = -EBUSY;
goto out;
}
file->private_data = perf;
perf->open = true;
perf->cnt = 0;
perf->buftot = 0;
perf->bufpos = 0;
msm_gpu_perfcntr_start(gpu);
perf->next_jiffies = jiffies + SAMPLE_TIME;
out:
mutex_unlock(&dev->struct_mutex);
return ret;
}
static int perf_release(struct inode *inode, struct file *file)
{
struct msm_perf_state *perf = inode->i_private;
struct msm_drm_private *priv = perf->dev->dev_private;
msm_gpu_perfcntr_stop(priv->gpu);
perf->open = false;
return 0;
}
static const struct file_operations perf_debugfs_fops = {
.owner = THIS_MODULE,
.open = perf_open,
.read = perf_read,
.llseek = no_llseek,
.release = perf_release,
};
int msm_perf_debugfs_init(struct drm_minor *minor)
{
struct msm_drm_private *priv = minor->dev->dev_private;
struct msm_perf_state *perf;
/* only create on first minor: */
if (priv->perf)
return 0;
perf = kzalloc(sizeof(*perf), GFP_KERNEL);
if (!perf)
return -ENOMEM;
perf->dev = minor->dev;
mutex_init(&perf->read_lock);
priv->perf = perf;
perf->node = kzalloc(sizeof(*perf->node), GFP_KERNEL);
if (!perf->node)
goto fail;
perf->ent = debugfs_create_file("perf", S_IFREG | S_IRUGO,
minor->debugfs_root, perf, &perf_debugfs_fops);
if (!perf->ent) {
DRM_ERROR("Cannot create /sys/kernel/debug/dri/%s/perf\n",
minor->debugfs_root->d_name.name);
goto fail;
}
perf->node->minor = minor;
perf->node->dent = perf->ent;
perf->node->info_ent = NULL;
mutex_lock(&minor->debugfs_lock);
list_add(&perf->node->list, &minor->debugfs_list);
mutex_unlock(&minor->debugfs_lock);
return 0;
fail:
msm_perf_debugfs_cleanup(minor);
return -1;
}
void msm_perf_debugfs_cleanup(struct drm_minor *minor)
{
struct msm_drm_private *priv = minor->dev->dev_private;
struct msm_perf_state *perf = priv->perf;
if (!perf)
return;
priv->perf = NULL;
debugfs_remove(perf->ent);
if (perf->node) {
mutex_lock(&minor->debugfs_lock);
list_del(&perf->node->list);
mutex_unlock(&minor->debugfs_lock);
kfree(perf->node);
}
mutex_destroy(&perf->read_lock);
kfree(perf);
}
#endif