[PATCH 11/15] drm/i915: Support opening multiple concurrent perf streams

sourab.gupta
2016-06-02T05:17:30Z

This patch adds support for opening multiple concurrent perf streams for
different gpu engines, while having the restriction to open only a single
stream open for a particular gpu engine.
This enables userspace client to open multiple streams, one per engine,
at any time to capture sample data for multiple gpu engines.

Signed-off-by: Sourab Gupta <sourab.gupta@intel.com>
---
drivers/gpu/drm/i915/i915_drv.h | 2 +-
drivers/gpu/drm/i915/i915_perf.c | 69 ++++++++++++++++++++++------------------
2 files changed, 39 insertions(+), 32 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index a9a123b..9ccac83 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2161,7 +2161,7 @@ struct drm_i915_private {
spinlock_t hook_lock;

struct hrtimer poll_check_timer;
- struct i915_perf_stream *exclusive_stream;
+ struct i915_perf_stream *ring_stream[I915_NUM_ENGINES];
wait_queue_head_t poll_wq[I915_NUM_ENGINES];

struct {
diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index 65b4af6..aa3589e 100644
--- a/drivers/gpu/drm/i915/i915_perf.c
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -944,7 +944,7 @@ static int gen8_append_oa_reports(struct i915_perf_stream *stream,
* an invalid ID. It could be good to annotate these
* reports with a _CTX_SWITCH_AWAY reason later.
*/
- if (!dev_priv->perf.exclusive_stream->ctx ||
+ if (!stream->ctx ||
dev_priv->perf.oa.specific_ctx_id == ctx_id ||
dev_priv->perf.oa.oa_buffer.last_ctx_id == ctx_id) {

@@ -955,7 +955,7 @@ static int gen8_append_oa_reports(struct i915_perf_stream *stream,
* the switch-away reports with an invalid
* context id to be recognisable by userspace.
*/
- if (dev_priv->perf.exclusive_stream->ctx &&
+ if (stream->ctx &&
dev_priv->perf.oa.specific_ctx_id != ctx_id)
report32[2] = 0x1fffff;

@@ -1596,7 +1596,7 @@ static void i915_ring_stream_destroy(struct i915_perf_stream *stream)
{
struct drm_i915_private *dev_priv = stream->dev_priv;

- BUG_ON(stream != dev_priv->perf.exclusive_stream);
+ BUG_ON(stream != dev_priv->perf.ring_stream[stream->engine]);

if (stream->using_oa) {
dev_priv->perf.oa.ops.disable_metric_set(dev_priv);
@@ -1610,7 +1610,7 @@ static void i915_ring_stream_destroy(struct i915_perf_stream *stream)
if (stream->cs_mode)
free_command_stream_buf(dev_priv, stream->engine);

- dev_priv->perf.exclusive_stream = NULL;
+ dev_priv->perf.ring_stream[stream->engine] = NULL;
}

static void gen7_init_oa_buffer(struct drm_i915_private *dev_priv)
@@ -2012,14 +2012,14 @@ static void gen7_update_oacontrol_locked(struct drm_i915_private *dev_priv)
{
assert_spin_locked(&dev_priv->perf.hook_lock);

- if (dev_priv->perf.exclusive_stream->state !=
+ if (dev_priv->perf.ring_stream[RCS]->state !=
I915_PERF_STREAM_DISABLED) {
unsigned long ctx_id = 0;

- if (dev_priv->perf.exclusive_stream->ctx)
+ if (dev_priv->perf.ring_stream[RCS]->ctx)
ctx_id = dev_priv->perf.oa.specific_ctx_id;

- if (dev_priv->perf.exclusive_stream->ctx == NULL || ctx_id) {
+ if (dev_priv->perf.ring_stream[RCS]->ctx == NULL || ctx_id) {
bool periodic = dev_priv->perf.oa.periodic;
u32 period_exponent = dev_priv->perf.oa.period_exponent;
u32 report_format = dev_priv->perf.oa.oa_buffer.format;
@@ -2144,15 +2144,6 @@ static int i915_ring_stream_init(struct i915_perf_stream *stream,
SAMPLE_TS);
int ret;

- /* To avoid the complexity of having to accurately filter
- * counter reports and marshal to the appropriate client
- * we currently only allow exclusive access
- */
- if (dev_priv->perf.exclusive_stream) {
- DRM_ERROR("Stream already in use\n");
- return -EBUSY;
- }
-
if ((props->sample_flags & SAMPLE_CTX_ID) && !props->cs_mode) {
if (IS_HASWELL(dev_priv->dev)) {
DRM_ERROR(
@@ -2170,6 +2161,12 @@ static int i915_ring_stream_init(struct i915_perf_stream *stream,
if (require_oa_unit) {
int format_size;

+ /* Only allow exclusive access per stream */
+ if (dev_priv->perf.ring_stream[RCS]) {
+ DRM_ERROR("Stream:0 already in use\n");
+ return -EBUSY;
+ }
+
if (!dev_priv->perf.oa.ops.init_oa_buffer) {
DRM_ERROR("OA unit not supported\n");
return -ENODEV;
@@ -2305,6 +2302,13 @@ static int i915_ring_stream_init(struct i915_perf_stream *stream,
}

if (props->cs_mode) {
+ /* Only allow exclusive access per stream */
+ if (dev_priv->perf.ring_stream[props->engine]) {
+ DRM_ERROR("Stream:%d already in use\n", props->engine);
+ ret = -EBUSY;
+ goto cs_error;
+ }
+
if (!cs_sample_data) {
DRM_ERROR(
"Ring given without requesting any CS data to sample");
@@ -2345,7 +2349,7 @@ static int i915_ring_stream_init(struct i915_perf_stream *stream,

stream->ops = &i915_oa_stream_ops;

- dev_priv->perf.exclusive_stream = stream;
+ dev_priv->perf.ring_stream[stream->engine] = stream;

return 0;

@@ -2379,8 +2383,8 @@ static void i915_oa_context_pin_notify_locked(struct drm_i915_private *dev_priv,
dev_priv->perf.oa.ops.update_hw_ctx_id_locked == NULL)
return;

- if (dev_priv->perf.exclusive_stream &&
- dev_priv->perf.exclusive_stream->ctx == context) {
+ if (dev_priv->perf.ring_stream[RCS] &&
+ dev_priv->perf.ring_stream[RCS]->ctx == context) {
struct drm_i915_gem_object *obj =
context->legacy_hw_ctx.rcs_state;
u32 ctx_id = i915_gem_obj_ggtt_offset(obj);
@@ -2449,8 +2453,8 @@ void i915_oa_legacy_ctx_switch_notify(struct drm_i915_gem_request *req)
if (dev_priv->perf.oa.ops.legacy_ctx_switch_unlocked == NULL)
return;

- if (dev_priv->perf.exclusive_stream &&
- dev_priv->perf.exclusive_stream->state !=
+ if (dev_priv->perf.ring_stream[RCS] &&
+ dev_priv->perf.ring_stream[RCS]->state !=
I915_PERF_STREAM_DISABLED) {

/* XXX: We don't take a lock here and this may run
@@ -2591,23 +2595,26 @@ static ssize_t i915_perf_read(struct file *file,
return ret;
}

-static enum hrtimer_restart poll_check_timer_cb(struct hrtimer *hrtimer)
+static void wake_up_perf_streams(void *data, async_cookie_t cookie)
{
+ struct drm_i915_private *dev_priv = data;
struct i915_perf_stream *stream;

- struct drm_i915_private *dev_priv =
- container_of(hrtimer, typeof(*dev_priv),
- perf.poll_check_timer);
-
- /* No need to protect the streams list here, since the hrtimer is
- * disabled before the stream is removed from list, and currently a
- * single exclusive_stream is supported.
- * XXX: revisit this when multiple concurrent streams are supported.
- */
+ mutex_lock(&dev_priv->perf.streams_lock);
list_for_each_entry(stream, &dev_priv->perf.streams, link) {
if (stream_have_data__unlocked(stream))
wake_up(&dev_priv->perf.poll_wq[stream->engine]);
}
+ mutex_unlock(&dev_priv->perf.streams_lock);
+}
+
+static enum hrtimer_restart poll_check_timer_cb(struct hrtimer *hrtimer)
+{
+ struct drm_i915_private *dev_priv =
+ container_of(hrtimer, typeof(*dev_priv),
+ perf.poll_check_timer);
+
+ async_schedule(wake_up_perf_streams, dev_priv);

hrtimer_forward_now(hrtimer, ns_to_ktime(POLL_PERIOD));