On Mon, Nov 04, 2019 at 06:38:01PM +0100, Daniel Vetter wrote:
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.
v2:
- Dont forget wu_mutex (Christian König)
- Keep the mmap_sem-less wait optimization (Thomas)
- Use _lock_interruptible to be good citizens (Thomas)
v3: Rebase over fault handler helperification.
Reviewed-by: Christian König christian.koenig@amd.com (v2) Reviewed-by: Thomas Hellström thellstrom@vmware.com (v2) 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
Entire series merged into drm-misc-next (probably for 5.6) with Dave's irc-ack for the nouveau patch. -Daniel
drivers/gpu/drm/ttm/ttm_bo.c | 36 ------------------------------- drivers/gpu/drm/ttm/ttm_bo_util.c | 1 - drivers/gpu/drm/ttm/ttm_bo_vm.c | 18 +++++----------- include/drm/ttm/ttm_bo_api.h | 4 ---- 4 files changed, 5 insertions(+), 54 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c index 8d91b0428af1..5df596fb0280 100644 --- a/drivers/gpu/drm/ttm/ttm_bo.c +++ b/drivers/gpu/drm/ttm/ttm_bo.c @@ -161,7 +161,6 @@ static void ttm_bo_release_list(struct kref *list_kref) dma_fence_put(bo->moving); if (!ttm_bo_uses_embedded_gem_object(bo)) dma_resv_fini(&bo->base._resv);
- mutex_destroy(&bo->wu_mutex); bo->destroy(bo); ttm_mem_global_free(&ttm_mem_glob, acc_size);
} @@ -1299,7 +1298,6 @@ int ttm_bo_init_reserved(struct ttm_bo_device *bdev, INIT_LIST_HEAD(&bo->ddestroy); INIT_LIST_HEAD(&bo->swap); INIT_LIST_HEAD(&bo->io_reserve_lru);
- mutex_init(&bo->wu_mutex); bo->bdev = bdev; bo->type = type; bo->num_pages = num_pages;
@@ -1903,37 +1901,3 @@ void ttm_bo_swapout_all(struct ttm_bo_device *bdev) while (ttm_bo_swapout(&ttm_bo_glob, &ctx) == 0); } 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_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c index 6b0883a1776e..2b0e5a088da0 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_util.c +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c @@ -504,7 +504,6 @@ static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo, INIT_LIST_HEAD(&fbo->base.lru); INIT_LIST_HEAD(&fbo->base.swap); INIT_LIST_HEAD(&fbo->base.io_reserve_lru);
- mutex_init(&fbo->base.wu_mutex); fbo->base.moving = NULL; drm_vma_node_reset(&fbo->base.base.vma_node);
diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c index 11863fbdd5d6..91466cfb6f16 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c @@ -128,30 +128,22 @@ static unsigned long ttm_bo_io_mem_pfn(struct ttm_buffer_object *bo, vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo, struct vm_fault *vmf) {
- /*
* 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.*/(void) ttm_bo_wait_unreserved(bo);
if (!dma_resv_lock_interruptible(bo->base.resv,NULL))dma_resv_unlock(bo->base.resv); 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;
if (dma_resv_lock_interruptible(bo->base.resv, NULL))return VM_FAULT_NOPAGE;}
return 0;
diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h index 65e399d280f7..e8b0f0c66059 100644 --- a/include/drm/ttm/ttm_bo_api.h +++ b/include/drm/ttm/ttm_bo_api.h @@ -154,7 +154,6 @@ struct ttm_tt;
- @offset: The current GPU offset, which can have different meanings
- depending on the memory type. For SYSTEM type memory, it should be 0.
- @cur_placement: Hint of current placement.
- @wu_mutex: Wait unreserved mutex.
- Base class for TTM buffer object, that deals with data placement and CPU
- mappings. GPU mappings are really up to the driver, but for simpler GPUs
@@ -222,8 +221,6 @@ struct ttm_buffer_object { uint64_t offset; /* GPU address space is independent of CPU word size */
struct sg_table *sg;
- struct mutex wu_mutex;
};
/** @@ -707,7 +704,6 @@ 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
-- 2.24.0.rc2