[PATCH 4/6] drm/panthor: Use guards for resv locking

[Boris Brezillon <boris.brezillon@collabora.com>]

Now that we have guards for resv locks, we can use them to simplify the
core. The only manual lock/unlock remaining are the ones in
panthor_gem_try_evict_no_resv_wait(), because the lock/unlock are
in different for_each() loop scopes.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
---
 drivers/gpu/drm/panthor/panthor_gem.c | 77 ++++++++++++-----------------------
 drivers/gpu/drm/panthor/panthor_mmu.c | 16 ++++----
 2 files changed, 32 insertions(+), 61 deletions(-)

diff --git a/drivers/gpu/drm/panthor/panthor_gem.c b/drivers/gpu/drm/panthor/panthor_gem.c
index a6fddc380e7d..94facdc8cfe1 100644
--- a/drivers/gpu/drm/panthor/panthor_gem.c
+++ b/drivers/gpu/drm/panthor/panthor_gem.c
@@ -339,13 +339,9 @@ panthor_gem_dev_map_get_sgt_locked(struct panthor_gem_object *bo)
 struct sg_table *
 panthor_gem_get_dev_sgt(struct panthor_gem_object *bo)
 {
-	struct sg_table *sgt;
+	guard(dma_resv)(bo->base.resv);
 
-	dma_resv_lock(bo->base.resv, NULL);
-	sgt = panthor_gem_dev_map_get_sgt_locked(bo);
-	dma_resv_unlock(bo->base.resv);
-
-	return sgt;
+	return panthor_gem_dev_map_get_sgt_locked(bo);
 }
 
 static void
@@ -497,7 +493,7 @@ panthor_gem_prime_begin_cpu_access(struct dma_buf *dma_buf,
 	struct panthor_gem_object *bo = to_panthor_bo(obj);
 	struct dma_buf_attachment *attach;
 
-	dma_resv_lock(obj->resv, NULL);
+	guard(dma_resv)(obj->resv);
 	if (bo->dmap.sgt)
 		dma_sync_sgtable_for_cpu(drm_dev_dma_dev(dev), bo->dmap.sgt, dir);
 
@@ -510,7 +506,6 @@ panthor_gem_prime_begin_cpu_access(struct dma_buf *dma_buf,
 		if (sgt)
 			dma_sync_sgtable_for_cpu(attach->dev, sgt, dir);
 	}
-	dma_resv_unlock(obj->resv);
 
 	return 0;
 }
@@ -524,7 +519,7 @@ panthor_gem_prime_end_cpu_access(struct dma_buf *dma_buf,
 	struct panthor_gem_object *bo = to_panthor_bo(obj);
 	struct dma_buf_attachment *attach;
 
-	dma_resv_lock(obj->resv, NULL);
+	guard(dma_resv)(obj->resv);
 	list_for_each_entry(attach, &dma_buf->attachments, node) {
 		struct sg_table *sgt = attach->priv;
 
@@ -538,7 +533,6 @@ panthor_gem_prime_end_cpu_access(struct dma_buf *dma_buf,
 	if (bo->dmap.sgt)
 		dma_sync_sgtable_for_device(drm_dev_dma_dev(dev), bo->dmap.sgt, dir);
 
-	dma_resv_unlock(obj->resv);
 	return 0;
 }
 
@@ -625,19 +619,15 @@ static void panthor_gem_unpin_locked(struct drm_gem_object *obj)
 
 int panthor_gem_pin(struct panthor_gem_object *bo)
 {
-	int ret = 0;
-
 	if (drm_gem_is_imported(&bo->base))
 		return 0;
 
 	if (refcount_inc_not_zero(&bo->backing.pin_count))
 		return 0;
 
-	dma_resv_lock(bo->base.resv, NULL);
-	ret = panthor_gem_backing_pin_locked(bo);
-	dma_resv_unlock(bo->base.resv);
+	guard(dma_resv)(bo->base.resv);
 
-	return ret;
+	return panthor_gem_backing_pin_locked(bo);
 }
 
 void panthor_gem_unpin(struct panthor_gem_object *bo)
@@ -648,9 +638,8 @@ void panthor_gem_unpin(struct panthor_gem_object *bo)
 	if (refcount_dec_not_one(&bo->backing.pin_count))
 		return;
 
-	dma_resv_lock(bo->base.resv, NULL);
+	guard(dma_resv)(bo->base.resv);
 	panthor_gem_backing_unpin_locked(bo);
-	dma_resv_unlock(bo->base.resv);
 }
 
 int panthor_gem_swapin_locked(struct panthor_gem_object *bo)
@@ -759,13 +748,12 @@ static int panthor_gem_mmap(struct drm_gem_object *obj, struct vm_area_struct *v
 		return -EINVAL;
 
 	if (!refcount_inc_not_zero(&bo->cmap.mmap_count)) {
-		dma_resv_lock(obj->resv, NULL);
+		guard(dma_resv)(obj->resv);
 		if (!refcount_inc_not_zero(&bo->cmap.mmap_count)) {
 			refcount_set(&bo->cmap.mmap_count, 1);
 			guard(mutex)(&bo->base.gpuva.lock);
 			panthor_gem_update_reclaim_state_locked(bo, NULL);
 		}
-		dma_resv_unlock(obj->resv);
 	}
 
 	vm_flags_set(vma, VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP);
@@ -814,18 +802,12 @@ static vm_fault_t nonblocking_page_setup(struct vm_fault *vmf,
 {
 	struct vm_area_struct *vma = vmf->vma;
 	struct panthor_gem_object *bo = to_panthor_bo(vma->vm_private_data);
-	vm_fault_t ret;
 
-	if (!dma_resv_trylock(bo->base.resv))
+	ACQUIRE(dma_resv_try, resv_guard)(bo->base.resv);
+	if (ACQUIRE_ERR(dma_resv_try, &resv_guard) || !bo->backing.pages)
 		return VM_FAULT_RETRY;
 
-	if (bo->backing.pages)
-		ret = insert_page(vmf, order, bo->backing.pages[page_offset]);
-	else
-		ret = VM_FAULT_RETRY;
-
-	dma_resv_unlock(bo->base.resv);
-	return ret;
+	return insert_page(vmf, order, bo->backing.pages[page_offset]);
 }
 
 static vm_fault_t blocking_page_setup(struct vm_fault *vmf, unsigned int order,
@@ -835,8 +817,8 @@ static vm_fault_t blocking_page_setup(struct vm_fault *vmf, unsigned int order,
 	vm_fault_t ret;
 	int err;
 
-	err = dma_resv_lock_interruptible(bo->base.resv, NULL);
-	if (err)
+	ACQUIRE(dma_resv_intr, resv_guard)(bo->base.resv);
+	if (ACQUIRE_ERR(dma_resv_intr, &resv_guard))
 		return mmap_lock_held ? VM_FAULT_NOPAGE : VM_FAULT_RETRY;
 
 	err = panthor_gem_backing_get_pages_locked(bo);
@@ -857,8 +839,6 @@ static vm_fault_t blocking_page_setup(struct vm_fault *vmf, unsigned int order,
 			ret = VM_FAULT_RETRY;
 	}
 
-	dma_resv_unlock(bo->base.resv);
-
 	return ret;
 }
 
@@ -932,12 +912,12 @@ static void panthor_gem_vm_close(struct vm_area_struct *vma)
 	if (refcount_dec_not_one(&bo->cmap.mmap_count))
 		goto out;
 
-	dma_resv_lock(bo->base.resv, NULL);
-	if (refcount_dec_and_test(&bo->cmap.mmap_count)) {
-		guard(mutex)(&bo->base.gpuva.lock);
-		panthor_gem_update_reclaim_state_locked(bo, NULL);
+	scoped_guard(dma_resv, bo->base.resv) {
+		if (refcount_dec_and_test(&bo->cmap.mmap_count)) {
+			guard(mutex)(&bo->base.gpuva.lock);
+			panthor_gem_update_reclaim_state_locked(bo, NULL);
+		}
 	}
-	dma_resv_unlock(bo->base.resv);
 
 out:
 	drm_gem_object_put(&bo->base);
@@ -1161,21 +1141,18 @@ panthor_gem_sync(struct drm_gem_object *obj, u32 type,
 	if (size == 0)
 		return 0;
 
-	ret = dma_resv_lock_interruptible(bo->base.resv, NULL);
+	ACQUIRE(dma_resv_intr, resv_guard)(bo->base.resv);
+	ret = ACQUIRE_ERR(dma_resv_intr, &resv_guard);
 	if (ret)
 		return ret;
 
 	/* If there's no pages, there's no point pulling those back, bail out early. */
-	if (!bo->backing.pages) {
-		ret = 0;
-		goto out_unlock;
-	}
+	if (!bo->backing.pages)
+		return 0;
 
 	sgt = panthor_gem_dev_map_get_sgt_locked(bo);
-	if (IS_ERR(sgt)) {
-		ret = PTR_ERR(sgt);
-		goto out_unlock;
-	}
+	if (IS_ERR(sgt))
+		return PTR_ERR(sgt);
 
 	for_each_sgtable_dma_sg(sgt, sgl, count) {
 		if (size == 0)
@@ -1219,11 +1196,7 @@ panthor_gem_sync(struct drm_gem_object *obj, u32 type,
 			dma_sync_single_for_cpu(dma_dev, paddr, len, DMA_FROM_DEVICE);
 	}
 
-	ret = 0;
-
-out_unlock:
-	dma_resv_unlock(bo->base.resv);
-	return ret;
+	return 0;
 }
 
 /**
diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c
index 157eef286cb9..ab9a77e6a145 100644
--- a/drivers/gpu/drm/panthor/panthor_mmu.c
+++ b/drivers/gpu/drm/panthor/panthor_mmu.c
@@ -1118,10 +1118,10 @@ static void panthor_vm_bo_free(struct drm_gpuvm_bo *vm_bo)
 	/* We couldn't call this when we unlinked, because the resv lock can't
 	 * be taken in the dma signalling path, so call it now.
 	 */
-	dma_resv_lock(bo->base.resv, NULL);
-	scoped_guard(mutex, &bo->base.gpuva.lock)
+	scoped_guard(dma_resv, bo->base.resv) {
+		guard(mutex)(&bo->base.gpuva.lock);
 		panthor_gem_update_reclaim_state_locked(bo, NULL);
-	dma_resv_unlock(bo->base.resv);
+	}
 
 	kfree(vm_bo);
 }
@@ -1342,16 +1342,14 @@ static int panthor_vm_prepare_map_op_ctx(struct panthor_vm_op_ctx *op_ctx,
 
 	/* Insert BO into the extobj list last, when we know nothing can fail. */
 	if (bo->base.resv != panthor_vm_resv(vm)) {
-		dma_resv_lock(panthor_vm_resv(vm), NULL);
+		guard(dma_resv)(panthor_vm_resv(vm));
 		drm_gpuvm_bo_extobj_add(op_ctx->map.vm_bo);
-		dma_resv_unlock(panthor_vm_resv(vm));
 	}
 
 	/* And finally update the BO state. */
-	dma_resv_lock(bo->base.resv, NULL);
-	scoped_guard(mutex, &bo->base.gpuva.lock)
-		panthor_gem_update_reclaim_state_locked(bo, NULL);
-	dma_resv_unlock(bo->base.resv);
+	guard(dma_resv)(bo->base.resv);
+	guard(mutex)(&bo->base.gpuva.lock);
+	panthor_gem_update_reclaim_state_locked(bo, NULL);
 
 	return 0;
 

-- 
2.54.0