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drm/i915: Track ggtt fence reservations under its own mutex

We can reduce the locking for fence registers from the dev->struct_mutex
to a local mutex. We could introduce a mutex for the sole purpose of
tracking the fence acquisition, except there is a little bit of overlap
with the fault tracking, so use the i915_ggtt.mutex as it covers both.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190822060914.2671-1-chris@chris-wilson.co.uk
alistair/sunxi64-5.4-dsi
Chris Wilson 2019-08-22 07:09:12 +01:00
parent 8e458fe2ee
commit e2ccc50a3a
6 changed files with 87 additions and 49 deletions

View File

@ -1157,7 +1157,14 @@ static int evict_fence(void *data)
goto out_unlock;
}
err = i915_vma_pin(arg->vma, 0, 0, PIN_GLOBAL | PIN_MAPPABLE);
if (err) {
pr_err("Unable to pin vma for Y-tiled fence; err:%d\n", err);
goto out_unlock;
}
err = i915_vma_pin_fence(arg->vma);
i915_vma_unpin(arg->vma);
if (err) {
pr_err("Unable to pin Y-tiled fence; err:%d\n", err);
goto out_unlock;

View File

@ -172,14 +172,14 @@ static void free_vgpu_fence(struct intel_vgpu *vgpu)
intel_runtime_pm_get(&dev_priv->runtime_pm);
mutex_lock(&dev_priv->drm.struct_mutex);
mutex_lock(&dev_priv->ggtt.vm.mutex);
_clear_vgpu_fence(vgpu);
for (i = 0; i < vgpu_fence_sz(vgpu); i++) {
reg = vgpu->fence.regs[i];
i915_unreserve_fence(reg);
vgpu->fence.regs[i] = NULL;
}
mutex_unlock(&dev_priv->drm.struct_mutex);
mutex_unlock(&dev_priv->ggtt.vm.mutex);
intel_runtime_pm_put_unchecked(&dev_priv->runtime_pm);
}
@ -195,7 +195,7 @@ static int alloc_vgpu_fence(struct intel_vgpu *vgpu)
intel_runtime_pm_get(rpm);
/* Request fences from host */
mutex_lock(&dev_priv->drm.struct_mutex);
mutex_lock(&dev_priv->ggtt.vm.mutex);
for (i = 0; i < vgpu_fence_sz(vgpu); i++) {
reg = i915_reserve_fence(dev_priv);
@ -207,7 +207,7 @@ static int alloc_vgpu_fence(struct intel_vgpu *vgpu)
_clear_vgpu_fence(vgpu);
mutex_unlock(&dev_priv->drm.struct_mutex);
mutex_unlock(&dev_priv->ggtt.vm.mutex);
intel_runtime_pm_put_unchecked(rpm);
return 0;
out_free_fence:
@ -220,7 +220,7 @@ out_free_fence:
i915_unreserve_fence(reg);
vgpu->fence.regs[i] = NULL;
}
mutex_unlock(&dev_priv->drm.struct_mutex);
mutex_unlock(&dev_priv->ggtt.vm.mutex);
intel_runtime_pm_put_unchecked(rpm);
return -ENOSPC;
}

View File

@ -652,10 +652,11 @@ static int i915_gem_fence_regs_info(struct seq_file *m, void *data)
rcu_read_lock();
for (i = 0; i < i915->ggtt.num_fences; i++) {
struct i915_vma *vma = i915->ggtt.fence_regs[i].vma;
struct i915_fence_reg *reg = &i915->ggtt.fence_regs[i];
struct i915_vma *vma = reg->vma;
seq_printf(m, "Fence %d, pin count = %d, object = ",
i, i915->ggtt.fence_regs[i].pin_count);
i, atomic_read(&reg->pin_count));
if (!vma)
seq_puts(m, "unused");
else

View File

@ -299,15 +299,24 @@ static int fence_update(struct i915_fence_reg *fence,
*/
int i915_vma_put_fence(struct i915_vma *vma)
{
struct i915_ggtt *ggtt = i915_vm_to_ggtt(vma->vm);
struct i915_fence_reg *fence = vma->fence;
int err;
if (!fence)
return 0;
if (fence->pin_count)
if (atomic_read(&fence->pin_count))
return -EBUSY;
return fence_update(fence, NULL);
err = mutex_lock_interruptible(&ggtt->vm.mutex);
if (err)
return err;
err = fence_update(fence, NULL);
mutex_unlock(&ggtt->vm.mutex);
return err;
}
static struct i915_fence_reg *fence_find(struct drm_i915_private *i915)
@ -317,7 +326,7 @@ static struct i915_fence_reg *fence_find(struct drm_i915_private *i915)
list_for_each_entry(fence, &i915->ggtt.fence_list, link) {
GEM_BUG_ON(fence->vma && fence->vma->fence != fence);
if (fence->pin_count)
if (atomic_read(&fence->pin_count))
continue;
return fence;
@ -330,6 +339,48 @@ static struct i915_fence_reg *fence_find(struct drm_i915_private *i915)
return ERR_PTR(-EDEADLK);
}
static int __i915_vma_pin_fence(struct i915_vma *vma)
{
struct i915_ggtt *ggtt = i915_vm_to_ggtt(vma->vm);
struct i915_fence_reg *fence;
struct i915_vma *set = i915_gem_object_is_tiled(vma->obj) ? vma : NULL;
int err;
/* 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);
atomic_inc(&fence->pin_count);
if (!fence->dirty) {
list_move_tail(&fence->link, &ggtt->fence_list);
return 0;
}
} else if (set) {
fence = fence_find(vma->vm->i915);
if (IS_ERR(fence))
return PTR_ERR(fence);
GEM_BUG_ON(atomic_read(&fence->pin_count));
atomic_inc(&fence->pin_count);
} else {
return 0;
}
err = fence_update(fence, set);
if (err)
goto out_unpin;
GEM_BUG_ON(fence->vma != set);
GEM_BUG_ON(vma->fence != (set ? fence : NULL));
if (set)
return 0;
out_unpin:
atomic_dec(&fence->pin_count);
return err;
}
/**
* i915_vma_pin_fence - set up fencing for a vma
* @vma: vma to map through a fence reg
@ -350,8 +401,6 @@ static struct i915_fence_reg *fence_find(struct drm_i915_private *i915)
*/
int i915_vma_pin_fence(struct i915_vma *vma)
{
struct i915_fence_reg *fence;
struct i915_vma *set = i915_gem_object_is_tiled(vma->obj) ? vma : NULL;
int err;
/*
@ -359,39 +408,16 @@ int i915_vma_pin_fence(struct i915_vma *vma)
* must keep the device awake whilst using the fence.
*/
assert_rpm_wakelock_held(&vma->vm->i915->runtime_pm);
GEM_BUG_ON(!i915_vma_is_pinned(vma));
GEM_BUG_ON(!i915_vma_is_ggtt(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->ggtt.fence_list);
return 0;
}
} else if (set) {
fence = fence_find(vma->vm->i915);
if (IS_ERR(fence))
return PTR_ERR(fence);
GEM_BUG_ON(fence->pin_count);
fence->pin_count++;
} else
return 0;
err = fence_update(fence, set);
err = mutex_lock_interruptible(&vma->vm->mutex);
if (err)
goto out_unpin;
return err;
GEM_BUG_ON(fence->vma != set);
GEM_BUG_ON(vma->fence != (set ? fence : NULL));
err = __i915_vma_pin_fence(vma);
mutex_unlock(&vma->vm->mutex);
if (set)
return 0;
out_unpin:
fence->pin_count--;
return err;
}
@ -404,16 +430,17 @@ out_unpin:
*/
struct i915_fence_reg *i915_reserve_fence(struct drm_i915_private *i915)
{
struct i915_ggtt *ggtt = &i915->ggtt;
struct i915_fence_reg *fence;
int count;
int ret;
lockdep_assert_held(&i915->drm.struct_mutex);
lockdep_assert_held(&ggtt->vm.mutex);
/* Keep at least one fence available for the display engine. */
count = 0;
list_for_each_entry(fence, &i915->ggtt.fence_list, link)
count += !fence->pin_count;
list_for_each_entry(fence, &ggtt->fence_list, link)
count += !atomic_read(&fence->pin_count);
if (count <= 1)
return ERR_PTR(-ENOSPC);
@ -429,6 +456,7 @@ struct i915_fence_reg *i915_reserve_fence(struct drm_i915_private *i915)
}
list_del(&fence->link);
return fence;
}
@ -440,9 +468,11 @@ struct i915_fence_reg *i915_reserve_fence(struct drm_i915_private *i915)
*/
void i915_unreserve_fence(struct i915_fence_reg *fence)
{
lockdep_assert_held(&fence->i915->drm.struct_mutex);
struct i915_ggtt *ggtt = &fence->i915->ggtt;
list_add(&fence->link, &fence->i915->ggtt.fence_list);
lockdep_assert_held(&ggtt->vm.mutex);
list_add(&fence->link, &ggtt->fence_list);
}
/**

View File

@ -41,7 +41,7 @@ struct i915_fence_reg {
struct list_head link;
struct drm_i915_private *i915;
struct i915_vma *vma;
int pin_count;
atomic_t pin_count;
int id;
/**
* Whether the tiling parameters for the currently

View File

@ -426,8 +426,8 @@ int __must_check i915_vma_put_fence(struct i915_vma *vma);
static inline void __i915_vma_unpin_fence(struct i915_vma *vma)
{
GEM_BUG_ON(vma->fence->pin_count <= 0);
vma->fence->pin_count--;
GEM_BUG_ON(atomic_read(&vma->fence->pin_count) <= 0);
atomic_dec(&vma->fence->pin_count);
}
/**