drm/ttm: remove io_reserve_lru handling v3

That is not used any more.

v2: keep the NULL checks in TTM.
v3: remove unused variable
Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Ben Skeggs <bskeggs@redhat.com>
Link: https://patchwork.freedesktop.org/patch/388646/

drivers/gpu/drm/ttm/ttm_bo.c

@@ -263,11 +263,7 @@ static int ttm_bo_handle_move_mem(struct ttm_buffer_object *bo,
 	struct ttm_resource_manager *new_man = ttm_manager_type(bdev, mem->mem_type);
 	int ret;
 
-	ret = ttm_mem_io_lock(old_man, true);
-	if (unlikely(ret != 0))
-		goto out_err;
-	ttm_bo_unmap_virtual_locked(bo);
-	ttm_mem_io_unlock(old_man);
+	ttm_bo_unmap_virtual(bo);
 
 	/*
 	 * Create and bind a ttm if required.
@@ -538,7 +534,6 @@ static void ttm_bo_release(struct kref *kref)
 	struct ttm_buffer_object *bo =
 	    container_of(kref, struct ttm_buffer_object, kref);
 	struct ttm_bo_device *bdev = bo->bdev;
-	struct ttm_resource_manager *man = ttm_manager_type(bdev, bo->mem.mem_type);
 	size_t acc_size = bo->acc_size;
 	int ret;
 
@@ -556,9 +551,7 @@ static void ttm_bo_release(struct kref *kref)
 			bo->bdev->driver->release_notify(bo);
 
 		drm_vma_offset_remove(bdev->vma_manager, &bo->base.vma_node);
-		ttm_mem_io_lock(man, false);
-		ttm_mem_io_free_vm(bo);
-		ttm_mem_io_unlock(man);
+		ttm_mem_io_free(bdev, &bo->mem);
 	}
 
 	if (!dma_resv_test_signaled_rcu(bo->base.resv, true) ||
@@ -648,8 +641,6 @@ static int ttm_bo_evict(struct ttm_buffer_object *bo,
 
 	evict_mem = bo->mem;
 	evict_mem.mm_node = NULL;
-	evict_mem.bus.io_reserved_vm = false;
-	evict_mem.bus.io_reserved_count = 0;
 	evict_mem.bus.base = 0;
 	evict_mem.bus.offset = 0;
 	evict_mem.bus.addr = NULL;
@@ -1085,8 +1076,6 @@ static int ttm_bo_move_buffer(struct ttm_buffer_object *bo,
 	mem.num_pages = bo->num_pages;
 	mem.size = mem.num_pages << PAGE_SHIFT;
 	mem.page_alignment = bo->mem.page_alignment;
-	mem.bus.io_reserved_vm = false;
-	mem.bus.io_reserved_count = 0;
 	mem.bus.base = 0;
 	mem.bus.offset = 0;
 	mem.bus.addr = NULL;
@@ -1238,7 +1227,6 @@ int ttm_bo_init_reserved(struct ttm_bo_device *bdev,
 	INIT_LIST_HEAD(&bo->lru);
 	INIT_LIST_HEAD(&bo->ddestroy);
 	INIT_LIST_HEAD(&bo->swap);
-	INIT_LIST_HEAD(&bo->io_reserve_lru);
 	bo->bdev = bdev;
 	bo->type = type;
 	bo->num_pages = num_pages;
@@ -1247,8 +1235,6 @@ int ttm_bo_init_reserved(struct ttm_bo_device *bdev,
 	bo->mem.num_pages = bo->num_pages;
 	bo->mem.mm_node = NULL;
 	bo->mem.page_alignment = page_alignment;
-	bo->mem.bus.io_reserved_vm = false;
-	bo->mem.bus.io_reserved_count = 0;
 	bo->mem.bus.base = 0;
 	bo->mem.bus.offset = 0;
 	bo->mem.bus.addr = NULL;
@@ -1554,25 +1540,13 @@ EXPORT_SYMBOL(ttm_bo_device_init);
  * buffer object vm functions.
  */
 
-void ttm_bo_unmap_virtual_locked(struct ttm_buffer_object *bo)
-{
-	struct ttm_bo_device *bdev = bo->bdev;
-
-	drm_vma_node_unmap(&bo->base.vma_node, bdev->dev_mapping);
-	ttm_mem_io_free_vm(bo);
-}
-
 void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo)
 {
 	struct ttm_bo_device *bdev = bo->bdev;
-	struct ttm_resource_manager *man = ttm_manager_type(bdev, bo->mem.mem_type);
 
-	ttm_mem_io_lock(man, false);
-	ttm_bo_unmap_virtual_locked(bo);
-	ttm_mem_io_unlock(man);
+	drm_vma_node_unmap(&bo->base.vma_node, bdev->dev_mapping);
+	ttm_mem_io_free(bdev, &bo->mem);
 }
-
-
 EXPORT_SYMBOL(ttm_bo_unmap_virtual);
 
 int ttm_bo_wait(struct ttm_buffer_object *bo,

drivers/gpu/drm/ttm/ttm_bo_util.c

@@ -91,122 +91,42 @@ int ttm_bo_move_ttm(struct ttm_buffer_object *bo,
 }
 EXPORT_SYMBOL(ttm_bo_move_ttm);
 
-int ttm_mem_io_lock(struct ttm_resource_manager *man, bool interruptible)
-{
-	if (likely(!man->use_io_reserve_lru))
-		return 0;
-
-	if (interruptible)
-		return mutex_lock_interruptible(&man->io_reserve_mutex);
-
-	mutex_lock(&man->io_reserve_mutex);
-	return 0;
-}
-
-void ttm_mem_io_unlock(struct ttm_resource_manager *man)
-{
-	if (likely(!man->use_io_reserve_lru))
-		return;
-
-	mutex_unlock(&man->io_reserve_mutex);
-}
-
-static int ttm_mem_io_evict(struct ttm_resource_manager *man)
-{
-	struct ttm_buffer_object *bo;
-
-	bo = list_first_entry_or_null(&man->io_reserve_lru,
-				      struct ttm_buffer_object,
-				      io_reserve_lru);
-	if (!bo)
-		return -ENOSPC;
-
-	list_del_init(&bo->io_reserve_lru);
-	ttm_bo_unmap_virtual_locked(bo);
-	return 0;
-}
-
 int ttm_mem_io_reserve(struct ttm_bo_device *bdev,
 		       struct ttm_resource *mem)
 {
-	struct ttm_resource_manager *man = ttm_manager_type(bdev, mem->mem_type);
-	int ret;
-
-	if (mem->bus.io_reserved_count++)
+	if (mem->bus.base || mem->bus.offset || mem->bus.addr)
 		return 0;
 
+	mem->bus.is_iomem = false;
 	if (!bdev->driver->io_mem_reserve)
 		return 0;
 
-	mem->bus.addr = NULL;
-	mem->bus.offset = 0;
-	mem->bus.base = 0;
-	mem->bus.is_iomem = false;
-retry:
-	ret = bdev->driver->io_mem_reserve(bdev, mem);
-	if (ret == -ENOSPC) {
-		ret = ttm_mem_io_evict(man);
-		if (ret == 0)
-			goto retry;
-	}
-	return ret;
+	return bdev->driver->io_mem_reserve(bdev, mem);
 }
 
 void ttm_mem_io_free(struct ttm_bo_device *bdev,
 		     struct ttm_resource *mem)
 {
-	if (--mem->bus.io_reserved_count)
-		return;
-
-	if (!bdev->driver->io_mem_free)
+	if (!mem->bus.base && !mem->bus.offset && !mem->bus.addr)
 		return;
 
-	bdev->driver->io_mem_free(bdev, mem);
-}
-
-int ttm_mem_io_reserve_vm(struct ttm_buffer_object *bo)
-{
-	struct ttm_resource_manager *man = ttm_manager_type(bo->bdev, bo->mem.mem_type);
-	struct ttm_resource *mem = &bo->mem;
-	int ret;
-
-	if (mem->bus.io_reserved_vm)
-		return 0;
-
-	ret = ttm_mem_io_reserve(bo->bdev, mem);
-	if (unlikely(ret != 0))
-		return ret;
-	mem->bus.io_reserved_vm = true;
-	if (man->use_io_reserve_lru)
-		list_add_tail(&bo->io_reserve_lru,
-			      &man->io_reserve_lru);
-	return 0;
-}
-
-void ttm_mem_io_free_vm(struct ttm_buffer_object *bo)
-{
-	struct ttm_resource *mem = &bo->mem;
-
-	if (!mem->bus.io_reserved_vm)
-		return;
+	if (bdev->driver->io_mem_free)
+		bdev->driver->io_mem_free(bdev, mem);
 
-	mem->bus.io_reserved_vm = false;
-	list_del_init(&bo->io_reserve_lru);
-	ttm_mem_io_free(bo->bdev, mem);
+	mem->bus.base = 0;
+	mem->bus.offset = 0;
+	mem->bus.addr = NULL;
 }
 
 static int ttm_resource_ioremap(struct ttm_bo_device *bdev,
 			       struct ttm_resource *mem,
 			       void **virtual)
 {
-	struct ttm_resource_manager *man = ttm_manager_type(bdev, mem->mem_type);
 	int ret;
 	void *addr;
 
 	*virtual = NULL;
-	(void) ttm_mem_io_lock(man, false);
 	ret = ttm_mem_io_reserve(bdev, mem);
-	ttm_mem_io_unlock(man);
 	if (ret || !mem->bus.is_iomem)
 		return ret;
 
@@ -222,9 +142,7 @@ static int ttm_resource_ioremap(struct ttm_bo_device *bdev,
 			addr = ioremap(mem->bus.base + mem->bus.offset,
 				       bus_size);
 		if (!addr) {
-			(void) ttm_mem_io_lock(man, false);
 			ttm_mem_io_free(bdev, mem);
-			ttm_mem_io_unlock(man);
 			return -ENOMEM;
 		}
 	}
@@ -236,15 +154,9 @@ static void ttm_resource_iounmap(struct ttm_bo_device *bdev,
 				struct ttm_resource *mem,
 				void *virtual)
 {
-	struct ttm_resource_manager *man;
-
-	man = ttm_manager_type(bdev, mem->mem_type);
-
 	if (virtual && mem->bus.addr == NULL)
 		iounmap(virtual);
-	(void) ttm_mem_io_lock(man, false);
 	ttm_mem_io_free(bdev, mem);
-	ttm_mem_io_unlock(man);
 }
 
 static int ttm_copy_io_page(void *dst, void *src, unsigned long page)
@@ -458,7 +370,6 @@ static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo,
 	INIT_LIST_HEAD(&fbo->base.ddestroy);
 	INIT_LIST_HEAD(&fbo->base.lru);
 	INIT_LIST_HEAD(&fbo->base.swap);
-	INIT_LIST_HEAD(&fbo->base.io_reserve_lru);
 	fbo->base.moving = NULL;
 	drm_vma_node_reset(&fbo->base.base.vma_node);
 
@@ -573,8 +484,6 @@ int ttm_bo_kmap(struct ttm_buffer_object *bo,
 		unsigned long start_page, unsigned long num_pages,
 		struct ttm_bo_kmap_obj *map)
 {
-	struct ttm_resource_manager *man =
-		ttm_manager_type(bo->bdev, bo->mem.mem_type);
 	unsigned long offset, size;
 	int ret;
 
@@ -585,9 +494,7 @@ int ttm_bo_kmap(struct ttm_buffer_object *bo,
 	if (start_page > bo->num_pages)
 		return -EINVAL;
 
-	(void) ttm_mem_io_lock(man, false);
 	ret = ttm_mem_io_reserve(bo->bdev, &bo->mem);
-	ttm_mem_io_unlock(man);
 	if (ret)
 		return ret;
 	if (!bo->mem.bus.is_iomem) {
@@ -602,10 +509,6 @@ EXPORT_SYMBOL(ttm_bo_kmap);
 
 void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map)
 {
-	struct ttm_buffer_object *bo = map->bo;
-	struct ttm_resource_manager *man =
-		ttm_manager_type(bo->bdev, bo->mem.mem_type);
-
 	if (!map->virtual)
 		return;
 	switch (map->bo_kmap_type) {
@@ -623,9 +526,7 @@ void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map)
 	default:
 		BUG();
 	}
-	(void) ttm_mem_io_lock(man, false);
 	ttm_mem_io_free(map->bo->bdev, &map->bo->mem);
-	ttm_mem_io_unlock(man);
 	map->virtual = NULL;
 	map->page = NULL;
 }

drivers/gpu/drm/ttm/ttm_bo_vm.c

@@ -281,8 +281,6 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
 	pgoff_t i;
 	vm_fault_t ret = VM_FAULT_NOPAGE;
 	unsigned long address = vmf->address;
-	struct ttm_resource_manager *man =
-		ttm_manager_type(bdev, bo->mem.mem_type);
 
 	/*
 	 * Refuse to fault imported pages. This should be handled
@@ -321,24 +319,17 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
 	if (unlikely(ret != 0))
 		return ret;
 
-	err = ttm_mem_io_lock(man, true);
+	err = ttm_mem_io_reserve(bdev, &bo->mem);
 	if (unlikely(err != 0))
-		return VM_FAULT_NOPAGE;
-	err = ttm_mem_io_reserve_vm(bo);
-	if (unlikely(err != 0)) {
-		ret = VM_FAULT_SIGBUS;
-		goto out_io_unlock;
-	}
+		return VM_FAULT_SIGBUS;
 
 	page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
 		vma->vm_pgoff - drm_vma_node_start(&bo->base.vma_node);
 	page_last = vma_pages(vma) + vma->vm_pgoff -
 		drm_vma_node_start(&bo->base.vma_node);
 
-	if (unlikely(page_offset >= bo->num_pages)) {
-		ret = VM_FAULT_SIGBUS;
-		goto out_io_unlock;
-	}
+	if (unlikely(page_offset >= bo->num_pages))
+		return VM_FAULT_SIGBUS;
 
 	prot = ttm_io_prot(bo->mem.placement, prot);
 	if (!bo->mem.bus.is_iomem) {
@@ -350,21 +341,17 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
 		};
 
 		ttm = bo->ttm;
-		if (ttm_tt_populate(bo->ttm, &ctx)) {
-			ret = VM_FAULT_OOM;
-			goto out_io_unlock;
-		}
+		if (ttm_tt_populate(bo->ttm, &ctx))
+			return VM_FAULT_OOM;
 	} else {
 		/* Iomem should not be marked encrypted */
 		prot = pgprot_decrypted(prot);
 	}
 
 	/* We don't prefault on huge faults. Yet. */
-	if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && fault_page_size != 1) {
-		ret = ttm_bo_vm_insert_huge(vmf, bo, page_offset,
-					    fault_page_size, prot);
-		goto out_io_unlock;
-	}
+	if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && fault_page_size != 1)
+		return ttm_bo_vm_insert_huge(vmf, bo, page_offset,
+					     fault_page_size, prot);
 
 	/*
 	 * Speculatively prefault a number of pages. Only error on
@@ -376,8 +363,7 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
 		} else {
 			page = ttm->pages[page_offset];
 			if (unlikely(!page && i == 0)) {
-				ret = VM_FAULT_OOM;
-				goto out_io_unlock;
+				return VM_FAULT_OOM;
 			} else if (unlikely(!page)) {
 				break;
 			}
@@ -404,7 +390,7 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
 		/* Never error on prefaulted PTEs */
 		if (unlikely((ret & VM_FAULT_ERROR))) {
 			if (i == 0)
-				goto out_io_unlock;
+				return VM_FAULT_NOPAGE;
 			else
 				break;
 		}
@@ -413,9 +399,6 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
 		if (unlikely(++page_offset >= page_last))
 			break;
 	}
-	ret = VM_FAULT_NOPAGE;
-out_io_unlock:
-	ttm_mem_io_unlock(man);
 	return ret;
 }
 EXPORT_SYMBOL(ttm_bo_vm_fault_reserved);

drivers/gpu/drm/ttm/ttm_resource.c

@@ -65,10 +65,7 @@ void ttm_resource_manager_init(struct ttm_resource_manager *man,
 {
 	unsigned i;
 
-	man->use_io_reserve_lru = false;
-	mutex_init(&man->io_reserve_mutex);
 	spin_lock_init(&man->move_lock);
-	INIT_LIST_HEAD(&man->io_reserve_lru);
 	man->size = p_size;
 
 	for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i)

include/drm/ttm/ttm_bo_api.h

@@ -151,7 +151,6 @@ struct ttm_buffer_object {
 	struct list_head lru;
 	struct list_head ddestroy;
 	struct list_head swap;
-	struct list_head io_reserve_lru;
 
 	/**
 	 * Members protected by a bo reservation.

include/drm/ttm/ttm_bo_driver.h

@@ -441,11 +441,6 @@ void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo);
  */
 void ttm_bo_unmap_virtual_locked(struct ttm_buffer_object *bo);
 
-int ttm_mem_io_reserve_vm(struct ttm_buffer_object *bo);
-void ttm_mem_io_free_vm(struct ttm_buffer_object *bo);
-int ttm_mem_io_lock(struct ttm_resource_manager *man, bool interruptible);
-void ttm_mem_io_unlock(struct ttm_resource_manager *man);
-
 /**
  * ttm_bo_reserve:
  *

include/drm/ttm/ttm_resource.h

@@ -113,10 +113,6 @@ struct ttm_resource_manager_func {
  * @default_caching: The default caching policy used for a buffer object
  * placed in this memory type if the user doesn't provide one.
  * @func: structure pointer implementing the range manager. See above
- * @io_reserve_mutex: Mutex optionally protecting shared io_reserve structures
- * @use_io_reserve_lru: Use an lru list to try to unreserve io_mem_regions
- * reserved by the TTM vm system.
- * @io_reserve_lru: Optional lru list for unreserving io mem regions.
  * @move_lock: lock for move fence
  * static information. bdev::driver::io_mem_free is never used.
  * @lru: The lru list for this memory type.
@@ -134,16 +130,8 @@ struct ttm_resource_manager {
 	uint32_t available_caching;
 	uint32_t default_caching;
 	const struct ttm_resource_manager_func *func;
-	struct mutex io_reserve_mutex;
-	bool use_io_reserve_lru;
 	spinlock_t move_lock;
 
-	/*
-	 * Protected by @io_reserve_mutex:
-	 */
-
-	struct list_head io_reserve_lru;
-
 	/*
 	 * Protected by the global->lru_lock.
 	 */
@@ -163,8 +151,6 @@ struct ttm_resource_manager {
  * @base:		bus base address
  * @is_iomem:		is this io memory ?
  * @offset:		offset from the base address
- * @io_reserved_vm:     The VM system has a refcount in @io_reserved_count
- * @io_reserved_count:  Refcounting the numbers of callers to ttm_mem_io_reserve
  *
  * Structure indicating the bus placement of an object.
  */
@@ -173,8 +159,6 @@ struct ttm_bus_placement {
 	phys_addr_t	base;
 	unsigned long	offset;
 	bool		is_iomem;
-	bool		io_reserved_vm;
-	uint64_t        io_reserved_count;
 };
 
 /**