[PATCH 35/48] drm/i915: Piggy back hangstats off of contexts

Ben Widawsky
2013-12-06T22:15:00Z

To simplify the codepaths somewhat, we can simply always create a
context. Contexts already keep hangstat information. This prevents us
from having to differentiate at other parts in the code.

There is allocation overhead, but it should not be measurable.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
---
drivers/gpu/drm/i915/i915_drv.h | 7 ++++---
drivers/gpu/drm/i915/i915_gem.c | 2 +-
drivers/gpu/drm/i915/i915_gem_context.c | 26 ++++++++++++++------------
3 files changed, 19 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 94a6984..b071b00 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1756,7 +1756,6 @@ struct drm_i915_file_private {
} mm;
struct idr context_idr;

- struct i915_ctx_hang_stats hang_stats;
struct i915_hw_context *private_default_ctx;
atomic_t rps_wait_boost;
};
@@ -2241,12 +2240,14 @@ int i915_switch_context(struct intel_ring_buffer *ring,
void i915_gem_context_free(struct kref *ctx_ref);
static inline void i915_gem_context_reference(struct i915_hw_context *ctx)
{
- kref_get(&ctx->ref);
+ if (ctx->obj && HAS_HW_CONTEXTS(ctx->obj->base.dev))
+ kref_get(&ctx->ref);
}

static inline void i915_gem_context_unreference(struct i915_hw_context *ctx)
{
- kref_put(&ctx->ref, i915_gem_context_free);
+ if (ctx->obj && HAS_HW_CONTEXTS(ctx->obj->base.dev))
+ kref_put(&ctx->ref, i915_gem_context_free);
}

struct i915_ctx_hang_stats * __must_check
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index e7345a72..3a80d0f 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2323,7 +2323,7 @@ static void i915_set_reset_status(struct intel_ring_buffer *ring,
if (request->ctx && request->ctx->id != DEFAULT_CONTEXT_ID)
hs = &request->ctx->hang_stats;
else if (request->file_priv)
- hs = &request->file_priv->hang_stats;
+ hs = &request->file_priv->private_default_ctx->hang_stats;

if (hs) {
if (guilty) {
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 95f25a9..362de0d 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -490,15 +490,8 @@ i915_gem_context_get_hang_stats(struct drm_device *dev,
struct drm_file *file,
u32 id)
{
- struct drm_i915_file_private *file_priv = file->driver_priv;
struct i915_hw_context *ctx;

- if (id == DEFAULT_CONTEXT_ID)
- return &file_priv->hang_stats;
-
- if (!HAS_HW_CONTEXTS(dev))
- return ERR_PTR(-ENOENT);
-
ctx = i915_gem_context_get(file->driver_priv, id);
if (ctx == NULL)
return ERR_PTR(-ENOENT);
@@ -509,9 +502,15 @@ i915_gem_context_get_hang_stats(struct drm_device *dev,
int i915_gem_context_open(struct drm_device *dev, struct drm_file *file)
{
struct drm_i915_file_private *file_priv = file->driver_priv;
+ struct drm_i915_private *dev_priv = dev->dev_private;

- if (!HAS_HW_CONTEXTS(dev))
+ if (!HAS_HW_CONTEXTS(dev)) {
+ /* Cheat for hang stats */
+ file_priv->private_default_ctx =
+ kzalloc(sizeof(struct i915_hw_context), GFP_KERNEL);
+ file_priv->private_default_ctx->vm = &dev_priv->gtt.base;
return 0;
+ }

idr_init(&file_priv->context_idr);

@@ -532,8 +531,10 @@ void i915_gem_context_close(struct drm_device *dev, struct drm_file *file)
{
struct drm_i915_file_private *file_priv = file->driver_priv;

- if (!HAS_HW_CONTEXTS(dev))
+ if (!HAS_HW_CONTEXTS(dev)) {
+ kfree(file_priv->private_default_ctx);
return;
+ }

idr_for_each(&file_priv->context_idr, context_idr_cleanup, NULL);
i915_gem_context_unreference(file_priv->private_default_ctx);
@@ -722,9 +723,6 @@ int i915_switch_context(struct intel_ring_buffer *ring,

WARN_ON(!mutex_is_locked(&dev_priv->dev->struct_mutex));

- if (!HAS_HW_CONTEXTS(ring->dev))
- return 0;
-
if (file == NULL)
to = ring->default_context;
else
@@ -733,6 +731,10 @@ int i915_switch_context(struct intel_ring_buffer *ring,
if (to == NULL)
return -ENOENT;

+ /* We have the fake context, but don't supports switching. */
+ if (!HAS_HW_CONTEXTS(ring->dev))
+ return 0;
+
return do_switch(ring, to);
}

--
1.8.4.2