Am 20.08.19 um 16:53 schrieb Daniel Vetter:
With nouveau fixed all ttm-using drives have the correct nesting of mmap_sem vs dma_resv, and we can just lock the buffer.
Assuming I didn't screw up anything with my audit of course.
Signed-off-by: Daniel Vetter daniel.vetter@intel.com Cc: Christian Koenig christian.koenig@amd.com Cc: Huang Rui ray.huang@amd.com Cc: Gerd Hoffmann kraxel@redhat.com Cc: "VMware Graphics" linux-graphics-maintainer@vmware.com Cc: Thomas Hellstrom thellstrom@vmware.com
Yes, please. But one more point: you can now remove bo->wu_mutex as well!
Apart from that Reviewed-by: Christian König christian.koenig@amd.com
drivers/gpu/drm/ttm/ttm_bo.c | 34 --------------------------------- drivers/gpu/drm/ttm/ttm_bo_vm.c | 26 +------------------------ include/drm/ttm/ttm_bo_api.h | 1 - 3 files changed, 1 insertion(+), 60 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c index 20ff56f27aa4..a952dd624b06 100644 --- a/drivers/gpu/drm/ttm/ttm_bo.c +++ b/drivers/gpu/drm/ttm/ttm_bo.c @@ -1954,37 +1954,3 @@ void ttm_bo_swapout_all(struct ttm_bo_device *bdev) ; } EXPORT_SYMBOL(ttm_bo_swapout_all);
-/**
- ttm_bo_wait_unreserved - interruptible wait for a buffer object to become
- unreserved
- @bo: Pointer to buffer
- */
-int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo) -{
- int ret;
- /*
* In the absense of a wait_unlocked API,* Use the bo::wu_mutex to avoid triggering livelocks due to* concurrent use of this function. Note that this use of* bo::wu_mutex can go away if we change locking order to* mmap_sem -> bo::reserve.*/- ret = mutex_lock_interruptible(&bo->wu_mutex);
- if (unlikely(ret != 0))
return -ERESTARTSYS;- if (!dma_resv_is_locked(bo->base.resv))
goto out_unlock;- ret = dma_resv_lock_interruptible(bo->base.resv, NULL);
- if (ret == -EINTR)
ret = -ERESTARTSYS;- if (unlikely(ret != 0))
goto out_unlock;- dma_resv_unlock(bo->base.resv);
-out_unlock:
- mutex_unlock(&bo->wu_mutex);
- return ret;
-} diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c index 76eedb963693..505e1787aeea 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c @@ -125,31 +125,7 @@ static vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf) &bdev->man[bo->mem.mem_type]; struct vm_area_struct cvma;
- /*
* Work around locking order reversal in fault / nopfn* between mmap_sem and bo_reserve: Perform a trylock operation* for reserve, and if it fails, retry the fault after waiting* for the buffer to become unreserved.*/- if (unlikely(!dma_resv_trylock(bo->base.resv))) {
if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {if (!(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {ttm_bo_get(bo);up_read(&vmf->vma->vm_mm->mmap_sem);(void) ttm_bo_wait_unreserved(bo);ttm_bo_put(bo);}return VM_FAULT_RETRY;}/** If we'd want to change locking order to* mmap_sem -> bo::reserve, we'd use a blocking reserve here* instead of retrying the fault...*/return VM_FAULT_NOPAGE;- }
dma_resv_lock(bo->base.resv, NULL);
/*
- Refuse to fault imported pages. This should be handled
diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h index 43c4929a2171..6b50e624e3e2 100644 --- a/include/drm/ttm/ttm_bo_api.h +++ b/include/drm/ttm/ttm_bo_api.h @@ -765,7 +765,6 @@ ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp, int ttm_bo_swapout(struct ttm_bo_global *glob, struct ttm_operation_ctx *ctx); void ttm_bo_swapout_all(struct ttm_bo_device *bdev); -int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo);
/**
- ttm_bo_uses_embedded_gem_object - check if the given bo uses the