On 17/08/2022 16:09, Anshuman Gupta wrote:
Runtime resume the dgpu(when gem object lies in lmem).
This will transition the dgpu graphics function to D0
state if it was in D3 in order to access the mmap memory
mappings.
Cc: Matthew Auld <matthew.auld@xxxxxxxxx>
Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
Signed-off-by: Anshuman Gupta <anshuman.gupta@xxxxxxxxx>
---
drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 25 +++++++++++++++++++------
1 file changed, 19 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
index b49823d599e7..1e9b07473a8f 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
@@ -1020,6 +1020,7 @@ static vm_fault_t vm_fault_ttm(struct vm_fault *vmf)
struct ttm_buffer_object *bo = area->vm_private_data;
struct drm_device *dev = bo->base.dev;
struct drm_i915_gem_object *obj;
+ intel_wakeref_t wakeref = 0;
vm_fault_t ret;
int idx;
@@ -1027,18 +1028,24 @@ static vm_fault_t vm_fault_ttm(struct vm_fault *vmf)
if (!obj)
return VM_FAULT_SIGBUS;
+ if (i915_gem_object_is_lmem(obj))
We shouldn't call this without first locking the object (see
bo_vm_reserve below), since it could be in the process of being moved to
system memory or vice versa. For example, below we check is_lmem() again
(this time with the lock held), which might return true, even though
here it returned false, which means we can now race against the
i915_gem_runtime_suspend() modifying the list as we add something.
We ofc still need to audit all the kernel internal users that are
touching lmem though a CPU mapping, and making sure we have the right
pm_get/put wrapping those accesses.
+ wakeref = intel_runtime_pm_get(&to_i915(obj->base.dev)->runtime_pm);
+
/* Sanity check that we allow writing into this object */
if (unlikely(i915_gem_object_is_readonly(obj) &&
- area->vm_flags & VM_WRITE))
- return VM_FAULT_SIGBUS;
+ area->vm_flags & VM_WRITE)) {
+ ret = VM_FAULT_SIGBUS;
+ goto out_rpm;
+ }
ret = ttm_bo_vm_reserve(bo, vmf);
if (ret)
- return ret;
+ goto out_rpm;
if (obj->mm.madv != I915_MADV_WILLNEED) {
dma_resv_unlock(bo->base.resv);
- return VM_FAULT_SIGBUS;
+ ret = VM_FAULT_SIGBUS;
+ goto out_rpm;
}
if (!i915_ttm_resource_mappable(bo->resource)) {
@@ -1062,7 +1069,8 @@ static vm_fault_t vm_fault_ttm(struct vm_fault *vmf)
if (err) {
drm_dbg(dev, "Unable to make resource CPU accessible\n");
dma_resv_unlock(bo->base.resv);
- return VM_FAULT_SIGBUS;
+ ret = VM_FAULT_SIGBUS;
+ goto out_rpm;
}
}
@@ -1078,11 +1086,16 @@ static vm_fault_t vm_fault_ttm(struct vm_fault *vmf)
list_add(&obj->userfault_link, &to_gt(to_i915(obj->base.dev))->lmem_userfault_list);
if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT))
- return ret;
+ goto out_rpm;
i915_ttm_adjust_lru(obj);
dma_resv_unlock(bo->base.resv);
+
+out_rpm:
+ if (wakeref)
+ intel_runtime_pm_put(&to_i915(obj->base.dev)->runtime_pm, wakeref);
Do we need something like DRM_I915_USERFAULT_AUTOSUSPEND here?
+
return ret;
}
