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drm/i915: Add ww locking to vm_fault_gtt

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We want to start requiring the reservation_lock instead of obj->mm.lock
for pinning objects, take the ww lock inside vm_fault_gtt as a first step
towards the legacy lock removal.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200819140904.1708856-23-maarten.lankhorst@linux.intel.com
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
This commit is contained in:
Maarten Lankhorst 2020-08-19 16:09:02 +02:00 committed by Joonas Lahtinen
parent 15b6c92498
commit 3c0ffa277e
1 changed files with 35 additions and 20 deletions
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55
drivers/gpu/drm/i915/gem/i915_gem_mman.c
View File

@ -283,37 +283,46 @@ static vm_fault_t vm_fault_gtt(struct vm_fault *vmf)
struct intel_runtime_pm *rpm = &i915->runtime_pm;
struct i915_ggtt *ggtt = &i915->ggtt;
bool write = area->vm_flags & VM_WRITE;
struct i915_gem_ww_ctx ww;
intel_wakeref_t wakeref;
struct i915_vma *vma;
pgoff_t page_offset;
int srcu;
int ret;
/* Sanity check that we allow writing into this object */
if (i915_gem_object_is_readonly(obj) && write)
return VM_FAULT_SIGBUS;
/* We don't use vmf->pgoff since that has the fake offset */
page_offset = (vmf->address - area->vm_start) >> PAGE_SHIFT;
trace_i915_gem_object_fault(obj, page_offset, true, write);
ret = i915_gem_object_pin_pages(obj);
if (ret)
goto err;
wakeref = intel_runtime_pm_get(rpm);
ret = intel_gt_reset_trylock(ggtt->vm.gt, &srcu);
i915_gem_ww_ctx_init(&ww, true);
retry:
ret = i915_gem_object_lock(obj, &ww);
if (ret)
goto err_rpm;
/* Sanity check that we allow writing into this object */
if (i915_gem_object_is_readonly(obj) && write) {
ret = -EFAULT;
goto err_rpm;
}
ret = i915_gem_object_pin_pages(obj);
if (ret)
goto err_rpm;
ret = intel_gt_reset_trylock(ggtt->vm.gt, &srcu);
if (ret)
goto err_pages;
/* Now pin it into the GTT as needed */
vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0,
PIN_MAPPABLE |
PIN_NONBLOCK /* NOWARN */ |
PIN_NOEVICT);
if (IS_ERR(vma)) {
vma = i915_gem_object_ggtt_pin_ww(obj, &ww, NULL, 0, 0,
PIN_MAPPABLE |
PIN_NONBLOCK /* NOWARN */ |
PIN_NOEVICT);
if (IS_ERR(vma) && vma != ERR_PTR(-EDEADLK)) {
/* Use a partial view if it is bigger than available space */
struct i915_ggtt_view view =
compute_partial_view(obj, page_offset, MIN_CHUNK_PAGES);
@ -328,11 +337,11 @@ static vm_fault_t vm_fault_gtt(struct vm_fault *vmf)
* all hope that the hardware is able to track future writes.
*/
vma = i915_gem_object_ggtt_pin(obj, &view, 0, 0, flags);
if (IS_ERR(vma)) {
vma = i915_gem_object_ggtt_pin_ww(obj, &ww, &view, 0, 0, flags);
if (IS_ERR(vma) && vma != ERR_PTR(-EDEADLK)) {
flags = PIN_MAPPABLE;
view.type = I915_GGTT_VIEW_PARTIAL;
vma = i915_gem_object_ggtt_pin(obj, &view, 0, 0, flags);
vma = i915_gem_object_ggtt_pin_ww(obj, &ww, &view, 0, 0, flags);
}
/* The entire mappable GGTT is pinned? Unexpected! */
@ -389,10 +398,16 @@ err_unpin:
__i915_vma_unpin(vma);
err_reset:
intel_gt_reset_unlock(ggtt->vm.gt, srcu);
err_rpm:
intel_runtime_pm_put(rpm, wakeref);
err_pages:
i915_gem_object_unpin_pages(obj);
err:
err_rpm:
if (ret == -EDEADLK) {
ret = i915_gem_ww_ctx_backoff(&ww);
if (!ret)
goto retry;
}
i915_gem_ww_ctx_fini(&ww);
intel_runtime_pm_put(rpm, wakeref);
return i915_error_to_vmf_fault(ret);
}