[Intel-gfx] [PATCH 2/4] drm/i915: Consolidate get_fence with pin_fence
Tvrtko Ursulin
tvrtko.ursulin at linux.intel.com
Tue Jul 4 14:47:13 UTC 2017
On 03/07/2017 11:14, Chris Wilson wrote:
> Following the pattern now used for obj->mm.pages, use just pin_fence and
> unpin_fence to control access to the fence registers. I.e. instead of
> calling get_fence(); pin_fence(), we now just need to call pin_fence().
> This will make it easier to reduce the locking requirements around
> fence registers.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
> drivers/gpu/drm/i915/i915_drv.h | 4 ----
> drivers/gpu/drm/i915/i915_gem.c | 3 ++-
> drivers/gpu/drm/i915/i915_gem_execbuffer.c | 10 +++++-----
> drivers/gpu/drm/i915/i915_gem_fence_reg.c | 27 ++++++++++++++++++++++-----
> drivers/gpu/drm/i915/i915_vma.c | 3 +--
> drivers/gpu/drm/i915/i915_vma.h | 20 ++++++++------------
> drivers/gpu/drm/i915/intel_display.c | 3 +--
> 7 files changed, 39 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 0029bb949e90..b08b56a2e680 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -3545,10 +3545,6 @@ i915_vm_to_ppgtt(struct i915_address_space *vm)
> return container_of(vm, struct i915_hw_ppgtt, base);
> }
>
> -/* i915_gem_fence_reg.c */
> -int __must_check i915_vma_get_fence(struct i915_vma *vma);
> -int __must_check i915_vma_put_fence(struct i915_vma *vma);
> -
> void i915_gem_revoke_fences(struct drm_i915_private *dev_priv);
> void i915_gem_restore_fences(struct drm_i915_private *dev_priv);
>
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 1b2dfa8bdeef..939a299260e9 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -1941,7 +1941,7 @@ int i915_gem_fault(struct vm_fault *vmf)
> if (ret)
> goto err_unpin;
>
> - ret = i915_vma_get_fence(vma);
> + ret = i915_vma_pin_fence(vma);
Hm, I think fence stealing stops working with this change?
Regards,
Tvrtko
> if (ret)
> goto err_unpin;
>
> @@ -1957,6 +1957,7 @@ int i915_gem_fault(struct vm_fault *vmf)
> min_t(u64, vma->size, area->vm_end - area->vm_start),
> &ggtt->mappable);
>
> + i915_vma_unpin_fence(vma);
> err_unpin:
> __i915_vma_unpin(vma);
> err_unlock:
> diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> index 929f275e67aa..22a9f5358322 100644
> --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> @@ -365,12 +365,12 @@ eb_pin_vma(struct i915_execbuffer *eb,
> return;
>
> if (unlikely(entry->flags & EXEC_OBJECT_NEEDS_FENCE)) {
> - if (unlikely(i915_vma_get_fence(vma))) {
> + if (unlikely(i915_vma_pin_fence(vma))) {
> i915_vma_unpin(vma);
> return;
> }
>
> - if (i915_vma_pin_fence(vma))
> + if (vma->fence)
> entry->flags |= __EXEC_OBJECT_HAS_FENCE;
> }
>
> @@ -384,7 +384,7 @@ __eb_unreserve_vma(struct i915_vma *vma,
> GEM_BUG_ON(!(entry->flags & __EXEC_OBJECT_HAS_PIN));
>
> if (unlikely(entry->flags & __EXEC_OBJECT_HAS_FENCE))
> - i915_vma_unpin_fence(vma);
> + __i915_vma_unpin_fence(vma);
>
> __i915_vma_unpin(vma);
> }
> @@ -564,13 +564,13 @@ static int eb_reserve_vma(const struct i915_execbuffer *eb,
> GEM_BUG_ON(eb_vma_misplaced(entry, vma));
>
> if (unlikely(entry->flags & EXEC_OBJECT_NEEDS_FENCE)) {
> - err = i915_vma_get_fence(vma);
> + err = i915_vma_pin_fence(vma);
> if (unlikely(err)) {
> i915_vma_unpin(vma);
> return err;
> }
>
> - if (i915_vma_pin_fence(vma))
> + if (vma->fence)
> entry->flags |= __EXEC_OBJECT_HAS_FENCE;
> }
>
> diff --git a/drivers/gpu/drm/i915/i915_gem_fence_reg.c b/drivers/gpu/drm/i915/i915_gem_fence_reg.c
> index 5fe2cd8c8f28..55ac7bc14fce 100644
> --- a/drivers/gpu/drm/i915/i915_gem_fence_reg.c
> +++ b/drivers/gpu/drm/i915/i915_gem_fence_reg.c
> @@ -280,8 +280,7 @@ static int fence_update(struct drm_i915_fence_reg *fence,
> *
> * 0 on success, negative error code on failure.
> */
> -int
> -i915_vma_put_fence(struct i915_vma *vma)
> +int i915_vma_put_fence(struct i915_vma *vma)
> {
> struct drm_i915_fence_reg *fence = vma->fence;
>
> @@ -299,6 +298,8 @@ static struct drm_i915_fence_reg *fence_find(struct drm_i915_private *dev_priv)
> struct drm_i915_fence_reg *fence;
>
> list_for_each_entry(fence, &dev_priv->mm.fence_list, link) {
> + GEM_BUG_ON(fence->vma && fence->vma->fence != fence);
> +
> if (fence->pin_count)
> continue;
>
> @@ -313,7 +314,7 @@ static struct drm_i915_fence_reg *fence_find(struct drm_i915_private *dev_priv)
> }
>
> /**
> - * i915_vma_get_fence - set up fencing for a vma
> + * i915_vma_pin_fence - set up fencing for a vma
> * @vma: vma to map through a fence reg
> *
> * When mapping objects through the GTT, userspace wants to be able to write
> @@ -331,10 +332,11 @@ static struct drm_i915_fence_reg *fence_find(struct drm_i915_private *dev_priv)
> * 0 on success, negative error code on failure.
> */
> int
> -i915_vma_get_fence(struct i915_vma *vma)
> +i915_vma_pin_fence(struct i915_vma *vma)
> {
> struct drm_i915_fence_reg *fence;
> struct i915_vma *set = i915_gem_object_is_tiled(vma->obj) ? vma : NULL;
> + int err;
>
> /* Note that we revoke fences on runtime suspend. Therefore the user
> * must keep the device awake whilst using the fence.
> @@ -344,6 +346,8 @@ i915_vma_get_fence(struct i915_vma *vma)
> /* Just update our place in the LRU if our fence is getting reused. */
> if (vma->fence) {
> fence = vma->fence;
> + GEM_BUG_ON(fence->vma != vma);
> + fence->pin_count++;
> if (!fence->dirty) {
> list_move_tail(&fence->link,
> &fence->i915->mm.fence_list);
> @@ -353,10 +357,19 @@ i915_vma_get_fence(struct i915_vma *vma)
> fence = fence_find(vma->vm->i915);
> if (IS_ERR(fence))
> return PTR_ERR(fence);
> + fence->pin_count++;
> } else
> return 0;
>
> - return fence_update(fence, set);
> + err = fence_update(fence, set);
> + if (err)
> + goto err_unpin;
> +
> + return 0;
> +
> +err_unpin:
> + fence->pin_count--;
> + return err;
> }
>
> /**
> @@ -378,6 +391,8 @@ void i915_gem_revoke_fences(struct drm_i915_private *dev_priv)
> for (i = 0; i < dev_priv->num_fence_regs; i++) {
> struct drm_i915_fence_reg *fence = &dev_priv->fence_regs[i];
>
> + GEM_BUG_ON(fence->vma && fence->vma->fence != fence);
> +
> if (fence->vma)
> i915_gem_release_mmap(fence->vma->obj);
> }
> @@ -399,6 +414,8 @@ void i915_gem_restore_fences(struct drm_i915_private *dev_priv)
> struct drm_i915_fence_reg *reg = &dev_priv->fence_regs[i];
> struct i915_vma *vma = reg->vma;
>
> + GEM_BUG_ON(vma && vma->fence != reg);
> +
> /*
> * Commit delayed tiling changes if we have an object still
> * attached to the fence, otherwise just clear the fence.
> diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
> index d7330d3eeab6..efbfee8eac99 100644
> --- a/drivers/gpu/drm/i915/i915_vma.c
> +++ b/drivers/gpu/drm/i915/i915_vma.c
> @@ -303,12 +303,11 @@ void __iomem *i915_vma_pin_iomap(struct i915_vma *vma)
>
> __i915_vma_pin(vma);
>
> - ret = i915_vma_get_fence(vma);
> + ret = i915_vma_pin_fence(vma);
> if (ret) {
> __i915_vma_unpin(vma);
> return IO_ERR_PTR(ret);
> }
> - i915_vma_pin_fence(vma);
>
> return ptr;
> }
> diff --git a/drivers/gpu/drm/i915/i915_vma.h b/drivers/gpu/drm/i915/i915_vma.h
> index 15e86e50a825..19f58af4f1bf 100644
> --- a/drivers/gpu/drm/i915/i915_vma.h
> +++ b/drivers/gpu/drm/i915/i915_vma.h
> @@ -342,15 +342,13 @@ static inline struct page *i915_vma_first_page(struct i915_vma *vma)
> *
> * True if the vma has a fence, false otherwise.
> */
> -static inline bool
> -i915_vma_pin_fence(struct i915_vma *vma)
> +int i915_vma_pin_fence(struct i915_vma *vma);
> +int __must_check i915_vma_put_fence(struct i915_vma *vma);
> +
> +static inline void __i915_vma_unpin_fence(struct i915_vma *vma)
> {
> - lockdep_assert_held(&vma->obj->base.dev->struct_mutex);
> - if (vma->fence) {
> - vma->fence->pin_count++;
> - return true;
> - } else
> - return false;
> + GEM_BUG_ON(vma->fence->pin_count <= 0);
> + vma->fence->pin_count--;
> }
>
> /**
> @@ -365,10 +363,8 @@ static inline void
> i915_vma_unpin_fence(struct i915_vma *vma)
> {
> lockdep_assert_held(&vma->obj->base.dev->struct_mutex);
> - if (vma->fence) {
> - GEM_BUG_ON(vma->fence->pin_count <= 0);
> - vma->fence->pin_count--;
> - }
> + if (vma->fence)
> + __i915_vma_unpin_fence(vma);
> }
>
> #endif
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 4e03ca6c946f..432bbaf460b4 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -2183,8 +2183,7 @@ intel_pin_and_fence_fb_obj(struct drm_framebuffer *fb, unsigned int rotation)
> * something and try to run the system in a "less than optimal"
> * mode that matches the user configuration.
> */
> - if (i915_vma_get_fence(vma) == 0)
> - i915_vma_pin_fence(vma);
> + i915_vma_pin_fence(vma);
> }
>
> i915_vma_get(vma);
>
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