[PATCH v2 1/3] drm/ttm: split BO structure initialization into a separate function
Nicolai Hähnle
nhaehnle at gmail.com
Wed Feb 15 19:10:54 UTC 2017
From: Nicolai Hähnle <nicolai.haehnle at amd.com>
Allow callers to opt out of calling ttm_bo_validate immediately. This
allows more flexibility in how locking of the reservation object is
done, which is needed to fix a locking bug (destroy locked mutex)
in amdgpu.
v2: callers of ttm_bo_init_top should use ttm_bo_unref for error
handling
Signed-off-by: Nicolai Hähnle <nicolai.haehnle at amd.com>
---
drivers/gpu/drm/ttm/ttm_bo.c | 89 ++++++++++++++++++++++++++++----------------
include/drm/ttm/ttm_bo_api.h | 44 ++++++++++++++++++++++
2 files changed, 100 insertions(+), 33 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index c438b04..390b763 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -1119,44 +1119,23 @@ int ttm_bo_validate(struct ttm_buffer_object *bo,
}
EXPORT_SYMBOL(ttm_bo_validate);
-int ttm_bo_init(struct ttm_bo_device *bdev,
- struct ttm_buffer_object *bo,
- unsigned long size,
- enum ttm_bo_type type,
- struct ttm_placement *placement,
- uint32_t page_alignment,
- bool interruptible,
- struct file *persistent_swap_storage,
- size_t acc_size,
- struct sg_table *sg,
- struct reservation_object *resv,
- void (*destroy) (struct ttm_buffer_object *))
+int ttm_bo_init_top(struct ttm_bo_device *bdev,
+ struct ttm_buffer_object *bo,
+ unsigned long size,
+ enum ttm_bo_type type,
+ uint32_t page_alignment,
+ struct file *persistent_swap_storage,
+ size_t acc_size,
+ struct sg_table *sg,
+ struct reservation_object *resv,
+ void (*destroy) (struct ttm_buffer_object *))
{
int ret = 0;
unsigned long num_pages;
struct ttm_mem_global *mem_glob = bdev->glob->mem_glob;
- bool locked;
-
- ret = ttm_mem_global_alloc(mem_glob, acc_size, false, false);
- if (ret) {
- pr_err("Out of kernel memory\n");
- if (destroy)
- (*destroy)(bo);
- else
- kfree(bo);
- return -ENOMEM;
- }
num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
- if (num_pages == 0) {
- pr_err("Illegal buffer object size\n");
- if (destroy)
- (*destroy)(bo);
- else
- kfree(bo);
- ttm_mem_global_free(mem_glob, acc_size);
- return -EINVAL;
- }
+
bo->destroy = destroy;
kref_init(&bo->kref);
@@ -1181,7 +1160,7 @@ int ttm_bo_init(struct ttm_bo_device *bdev,
bo->moving = NULL;
bo->mem.placement = (TTM_PL_FLAG_SYSTEM | TTM_PL_FLAG_CACHED);
bo->persistent_swap_storage = persistent_swap_storage;
- bo->acc_size = acc_size;
+ bo->acc_size = 0;
bo->sg = sg;
if (resv) {
bo->resv = resv;
@@ -1195,6 +1174,22 @@ int ttm_bo_init(struct ttm_bo_device *bdev,
bo->priority = 0;
/*
+ * Error checking comes after initialization, so that the regular
+ * buffer object cleanup code can be used safely by the caller.
+ */
+ if (num_pages == 0) {
+ pr_err("Illegal buffer object size\n");
+ return -EINVAL;
+ }
+
+ ret = ttm_mem_global_alloc(mem_glob, acc_size, false, false);
+ if (ret) {
+ pr_err("Out of kernel memory\n");
+ return -ENOMEM;
+ }
+ bo->acc_size = acc_size;
+
+ /*
* For ttm_bo_type_device buffers, allocate
* address space from the device.
*/
@@ -1203,6 +1198,34 @@ int ttm_bo_init(struct ttm_bo_device *bdev,
ret = drm_vma_offset_add(&bdev->vma_manager, &bo->vma_node,
bo->mem.num_pages);
+ return ret;
+}
+EXPORT_SYMBOL(ttm_bo_init_top);
+
+int ttm_bo_init(struct ttm_bo_device *bdev,
+ struct ttm_buffer_object *bo,
+ unsigned long size,
+ enum ttm_bo_type type,
+ struct ttm_placement *placement,
+ uint32_t page_alignment,
+ bool interruptible,
+ struct file *persistent_swap_storage,
+ size_t acc_size,
+ struct sg_table *sg,
+ struct reservation_object *resv,
+ void (*destroy) (struct ttm_buffer_object *))
+{
+ bool locked;
+ int ret;
+
+ ret = ttm_bo_init_top(bdev, bo, size, type, page_alignment,
+ persistent_swap_storage, acc_size, sg, resv,
+ destroy);
+ if (ret) {
+ ttm_bo_unref(&bo);
+ return ret;
+ }
+
/* passed reservation objects should already be locked,
* since otherwise lockdep will be angered in radeon.
*/
diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
index f195899..6e8eaee 100644
--- a/include/drm/ttm/ttm_bo_api.h
+++ b/include/drm/ttm/ttm_bo_api.h
@@ -453,6 +453,50 @@ size_t ttm_bo_dma_acc_size(struct ttm_bo_device *bdev,
unsigned struct_size);
/**
+ * ttm_bo_init_top
+ *
+ * @bdev: Pointer to a ttm_bo_device struct.
+ * @bo: Pointer to a ttm_buffer_object to be initialized.
+ * @size: Requested size of buffer object.
+ * @type: Requested type of buffer object.
+ * @flags: Initial placement flags.
+ * @page_alignment: Data alignment in pages.
+ * @persistent_swap_storage: Usually the swap storage is deleted for buffers
+ * pinned in physical memory. If this behaviour is not desired, this member
+ * holds a pointer to a persistent shmem object. Typically, this would
+ * point to the shmem object backing a GEM object if TTM is used to back a
+ * GEM user interface.
+ * @acc_size: Accounted size for this object.
+ * @resv: Pointer to a reservation_object, or NULL to let ttm allocate one.
+ * @destroy: Destroy function. Use NULL for kfree().
+ *
+ * This function initializes a pre-allocated struct ttm_buffer_object.
+ * As this object may be part of a larger structure, this function,
+ * together with the @destroy function,
+ * enables driver-specific objects derived from a ttm_buffer_object.
+ *
+ * Unlike ttm_bo_init, @bo is not validated, and when an error is returned,
+ * the caller is responsible for freeing @bo (using ttm_bo_unref).
+ *
+ * On successful return, the object kref and list_kref are set to 1.
+ *
+ * Returns
+ * -ENOMEM: Out of memory.
+ * -EINVAL: Invalid buffer size.
+ */
+
+extern int ttm_bo_init_top(struct ttm_bo_device *bdev,
+ struct ttm_buffer_object *bo,
+ unsigned long size,
+ enum ttm_bo_type type,
+ uint32_t page_alignment,
+ struct file *persistent_swap_storage,
+ size_t acc_size,
+ struct sg_table *sg,
+ struct reservation_object *resv,
+ void (*destroy) (struct ttm_buffer_object *));
+
+/**
* ttm_bo_init
*
* @bdev: Pointer to a ttm_bo_device struct.
--
2.9.3
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