From 5d82e3e6427d407e5e4713a2f73210b4e7801ad3 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Sat, 21 Apr 2012 16:23:23 +0100 Subject: [PATCH] drm/i915: Clarify the semantics of tiling_changed Rename obj->tiling_changed to obj->fence_dirty so that it is clear that it flags when the parameters for an active fence (including the no-fence) register are changed. Also, do not set this flag when the object does not have a fence register allocated currently and the gpu does not depend upon the unfence. This case works exactly like when a tiled object lost its fence and hence does not need additional handling for the tiling change in the code. v2: Use fence_dirty to better express what the flag tracks and add a few more details to the comments to serve as a reminder of how the GPU also uses the unfenced register slot. Signed-off-by: Chris Wilson [danvet: Add some bikeshed to the commit message about the stricter use of fence_dirty.] Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_drv.h | 9 ++++++++- drivers/gpu/drm/i915/i915_gem.c | 8 ++++---- drivers/gpu/drm/i915/i915_gem_tiling.c | 10 +++++++++- 3 files changed, 21 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 4cbc45f..faea1b6 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -869,7 +869,14 @@ struct drm_i915_gem_object { * Current tiling mode for the object. */ unsigned int tiling_mode:2; - unsigned int tiling_changed:1; + /** + * Whether the tiling parameters for the currently associated fence + * register have changed. Note that for the purposes of tracking + * tiling changes we also treat the unfenced register, the register + * slot that the object occupies whilst it executes a fenced + * command (such as BLT on gen2/3), as a "fence". + */ + unsigned int fence_dirty:1; /** How many users have pinned this object in GTT space. The following * users can each hold at most one reference: pwrite/pread, pin_ioctl diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 9e9ea75..38490cd 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -66,7 +66,7 @@ static inline void i915_gem_object_fence_lost(struct drm_i915_gem_object *obj) /* As we do not have an associated fence register, we will force * a tiling change if we ever need to acquire one. */ - obj->tiling_changed = false; + obj->fence_dirty = false; obj->fence_reg = I915_FENCE_REG_NONE; } @@ -2459,7 +2459,7 @@ i915_gem_object_get_fence(struct drm_i915_gem_object *obj) /* Have we updated the tiling parameters upon the object and so * will need to serialise the write to the associated fence register? */ - if (obj->tiling_changed) { + if (obj->fence_dirty) { ret = i915_gem_object_flush_fence(obj); if (ret) return ret; @@ -2468,7 +2468,7 @@ i915_gem_object_get_fence(struct drm_i915_gem_object *obj) /* Just update our place in the LRU if our fence is getting reused. */ if (obj->fence_reg != I915_FENCE_REG_NONE) { reg = &dev_priv->fence_regs[obj->fence_reg]; - if (!obj->tiling_changed) { + if (!obj->fence_dirty) { list_move_tail(®->lru_list, &dev_priv->mm.fence_list); return 0; @@ -2491,7 +2491,7 @@ i915_gem_object_get_fence(struct drm_i915_gem_object *obj) return 0; i915_gem_object_update_fence(obj, reg, enable); - obj->tiling_changed = false; + obj->fence_dirty = false; return 0; } diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c index 1a93066..c9786cd 100644 --- a/drivers/gpu/drm/i915/i915_gem_tiling.c +++ b/drivers/gpu/drm/i915/i915_gem_tiling.c @@ -355,6 +355,11 @@ i915_gem_set_tiling(struct drm_device *dev, void *data, * no longer meets the alignment restrictions for its new * tiling mode. Otherwise we can just leave it alone, but * need to ensure that any fence register is cleared. + * + * After updating the tiling parameters, we then flag whether + * we need to update an associated fence register. Note this + * has to also include the unfenced register the GPU uses + * whilst executing a fenced command for an untiled object. */ i915_gem_release_mmap(obj); @@ -374,7 +379,10 @@ i915_gem_set_tiling(struct drm_device *dev, void *data, } if (ret == 0) { - obj->tiling_changed = true; + obj->fence_dirty = + obj->fenced_gpu_access || + obj->fence_reg != I915_FENCE_REG_NONE; + obj->tiling_mode = args->tiling_mode; obj->stride = args->stride; } -- 2.7.4