From 3205bc242b5e3950c808049dbf199fca91f2c844 Mon Sep 17 00:00:00 2001 From: Thomas Hellstrom Date: Fri, 29 Oct 2010 10:46:44 +0200 Subject: drm/ttm: Documentation update Remove an obsolete comment about mm nodes. Document the new bo range manager interface. Signed-off-by: Thomas Hellstrom Signed-off-by: Dave Airlie --- include/drm/ttm/ttm_bo_driver.h | 79 ++++++++++++++++++++++++++++++++++++++--- 1 file changed, 74 insertions(+), 5 deletions(-) (limited to 'include') diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h index d01b4ddbdc5..8e0c848326b 100644 --- a/include/drm/ttm/ttm_bo_driver.h +++ b/include/drm/ttm/ttm_bo_driver.h @@ -206,14 +206,84 @@ struct ttm_tt { struct ttm_mem_type_manager; struct ttm_mem_type_manager_func { + /** + * struct ttm_mem_type_manager member init + * + * @man: Pointer to a memory type manager. + * @p_size: Implementation dependent, but typically the size of the + * range to be managed in pages. + * + * Called to initialize a private range manager. The function is + * expected to initialize the man::priv member. + * Returns 0 on success, negative error code on failure. + */ int (*init)(struct ttm_mem_type_manager *man, unsigned long p_size); + + /** + * struct ttm_mem_type_manager member takedown + * + * @man: Pointer to a memory type manager. + * + * Called to undo the setup done in init. All allocated resources + * should be freed. + */ int (*takedown)(struct ttm_mem_type_manager *man); + + /** + * struct ttm_mem_type_manager member get_node + * + * @man: Pointer to a memory type manager. + * @bo: Pointer to the buffer object we're allocating space for. + * @placement: Placement details. + * @mem: Pointer to a struct ttm_mem_reg to be filled in. + * + * This function should allocate space in the memory type managed + * by @man. Placement details if + * applicable are given by @placement. If successful, + * @mem::mm_node should be set to a non-null value, and + * @mem::start should be set to a value identifying the beginning + * of the range allocated, and the function should return zero. + * If the memory region accomodate the buffer object, @mem::mm_node + * should be set to NULL, and the function should return 0. + * If a system error occured, preventing the request to be fulfilled, + * the function should return a negative error code. + * + * Note that @mem::mm_node will only be dereferenced by + * struct ttm_mem_type_manager functions and optionally by the driver, + * which has knowledge of the underlying type. + * + * This function may not be called from within atomic context, so + * an implementation can and must use either a mutex or a spinlock to + * protect any data structures managing the space. + */ int (*get_node)(struct ttm_mem_type_manager *man, struct ttm_buffer_object *bo, struct ttm_placement *placement, struct ttm_mem_reg *mem); + + /** + * struct ttm_mem_type_manager member put_node + * + * @man: Pointer to a memory type manager. + * @mem: Pointer to a struct ttm_mem_reg to be filled in. + * + * This function frees memory type resources previously allocated + * and that are identified by @mem::mm_node and @mem::start. May not + * be called from within atomic context. + */ void (*put_node)(struct ttm_mem_type_manager *man, struct ttm_mem_reg *mem); + + /** + * struct ttm_mem_type_manager member debug + * + * @man: Pointer to a memory type manager. + * @prefix: Prefix to be used in printout to identify the caller. + * + * This function is called to print out the state of the memory + * type manager to aid debugging of out-of-memory conditions. + * It may not be called from within atomic context. + */ void (*debug)(struct ttm_mem_type_manager *man, const char *prefix); }; @@ -231,14 +301,13 @@ struct ttm_mem_type_manager { uint64_t size; uint32_t available_caching; uint32_t default_caching; + const struct ttm_mem_type_manager_func *func; + void *priv; /* - * Protected by the bdev->lru_lock. - * TODO: Consider one lru_lock per ttm_mem_type_manager. - * Plays ill with list removal, though. + * Protected by the global->lru_lock. */ - const struct ttm_mem_type_manager_func *func; - void *priv; + struct list_head lru; }; -- cgit v1.2.3-70-g09d2 From 7dfbbdcffebc41441e64278961f57d2840a76259 Mon Sep 17 00:00:00 2001 From: Thomas Hellstrom Date: Tue, 9 Nov 2010 21:31:44 +0100 Subject: drm/ttm: Be consistent on ttm_bo_init() failures Call destroy() on _all_ ttm_bo_init() failures, and make sure that behavior is documented in the function description. Signed-off-by: Thomas Hellstrom Signed-off-by: Dave Airlie --- drivers/gpu/drm/ttm/ttm_bo.c | 4 ++++ include/drm/ttm/ttm_bo_api.h | 4 ++++ 2 files changed, 8 insertions(+) (limited to 'include') diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c index ce464579c48..3ca77dc0391 100644 --- a/drivers/gpu/drm/ttm/ttm_bo.c +++ b/drivers/gpu/drm/ttm/ttm_bo.c @@ -1144,6 +1144,10 @@ int ttm_bo_init(struct ttm_bo_device *bdev, num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; if (num_pages == 0) { printk(KERN_ERR TTM_PFX "Illegal buffer object size.\n"); + if (destroy) + (*destroy)(bo); + else + kfree(bo); return -EINVAL; } bo->destroy = destroy; diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h index 5afa5b52063..beafc156a53 100644 --- a/include/drm/ttm/ttm_bo_api.h +++ b/include/drm/ttm/ttm_bo_api.h @@ -432,6 +432,10 @@ extern void ttm_bo_synccpu_write_release(struct ttm_buffer_object *bo); * together with the @destroy function, * enables driver-specific objects derived from a ttm_buffer_object. * On successful return, the object kref and list_kref are set to 1. + * If a failure occurs, the function will call the @destroy function, or + * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is + * illegal and will likely cause memory corruption. + * * Returns * -ENOMEM: Out of memory. * -EINVAL: Invalid placement flags. -- cgit v1.2.3-70-g09d2