diff options
Diffstat (limited to 'include/drm/drm_buddy.h')
| -rw-r--r-- | include/drm/drm_buddy.h | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/include/drm/drm_buddy.h b/include/drm/drm_buddy.h new file mode 100644 index 000000000000..b909fa8f810a --- /dev/null +++ b/include/drm/drm_buddy.h @@ -0,0 +1,171 @@ +/* SPDX-License-Identifier: MIT */ +/* + * Copyright © 2021 Intel Corporation + */ + +#ifndef __DRM_BUDDY_H__ +#define __DRM_BUDDY_H__ + +#include <linux/bitops.h> +#include <linux/list.h> +#include <linux/slab.h> +#include <linux/sched.h> +#include <linux/rbtree.h> + +struct drm_printer; + +#define DRM_BUDDY_RANGE_ALLOCATION BIT(0) +#define DRM_BUDDY_TOPDOWN_ALLOCATION BIT(1) +#define DRM_BUDDY_CONTIGUOUS_ALLOCATION BIT(2) +#define DRM_BUDDY_CLEAR_ALLOCATION BIT(3) +#define DRM_BUDDY_CLEARED BIT(4) +#define DRM_BUDDY_TRIM_DISABLE BIT(5) + +struct drm_buddy_block { +#define DRM_BUDDY_HEADER_OFFSET GENMASK_ULL(63, 12) +#define DRM_BUDDY_HEADER_STATE GENMASK_ULL(11, 10) +#define DRM_BUDDY_ALLOCATED (1 << 10) +#define DRM_BUDDY_FREE (2 << 10) +#define DRM_BUDDY_SPLIT (3 << 10) +#define DRM_BUDDY_HEADER_CLEAR GENMASK_ULL(9, 9) +/* Free to be used, if needed in the future */ +#define DRM_BUDDY_HEADER_UNUSED GENMASK_ULL(8, 6) +#define DRM_BUDDY_HEADER_ORDER GENMASK_ULL(5, 0) + u64 header; + + struct drm_buddy_block *left; + struct drm_buddy_block *right; + struct drm_buddy_block *parent; + + void *private; /* owned by creator */ + + /* + * While the block is allocated by the user through drm_buddy_alloc*, + * the user has ownership of the link, for example to maintain within + * a list, if so desired. As soon as the block is freed with + * drm_buddy_free* ownership is given back to the mm. + */ + union { + struct rb_node rb; + struct list_head link; + }; + + struct list_head tmp_link; +}; + +/* Order-zero must be at least SZ_4K */ +#define DRM_BUDDY_MAX_ORDER (63 - 12) + +/* + * Binary Buddy System. + * + * Locking should be handled by the user, a simple mutex around + * drm_buddy_alloc* and drm_buddy_free* should suffice. + */ +struct drm_buddy { + /* Maintain a free list for each order. */ + struct rb_root **free_trees; + + /* + * Maintain explicit binary tree(s) to track the allocation of the + * address space. This gives us a simple way of finding a buddy block + * and performing the potentially recursive merge step when freeing a + * block. Nodes are either allocated or free, in which case they will + * also exist on the respective free list. + */ + struct drm_buddy_block **roots; + + /* + * Anything from here is public, and remains static for the lifetime of + * the mm. Everything above is considered do-not-touch. + */ + unsigned int n_roots; + unsigned int max_order; + + /* Must be at least SZ_4K */ + u64 chunk_size; + u64 size; + u64 avail; + u64 clear_avail; +}; + +static inline u64 +drm_buddy_block_offset(const struct drm_buddy_block *block) +{ + return block->header & DRM_BUDDY_HEADER_OFFSET; +} + +static inline unsigned int +drm_buddy_block_order(struct drm_buddy_block *block) +{ + return block->header & DRM_BUDDY_HEADER_ORDER; +} + +static inline unsigned int +drm_buddy_block_state(struct drm_buddy_block *block) +{ + return block->header & DRM_BUDDY_HEADER_STATE; +} + +static inline bool +drm_buddy_block_is_allocated(struct drm_buddy_block *block) +{ + return drm_buddy_block_state(block) == DRM_BUDDY_ALLOCATED; +} + +static inline bool +drm_buddy_block_is_clear(struct drm_buddy_block *block) +{ + return block->header & DRM_BUDDY_HEADER_CLEAR; +} + +static inline bool +drm_buddy_block_is_free(struct drm_buddy_block *block) +{ + return drm_buddy_block_state(block) == DRM_BUDDY_FREE; +} + +static inline bool +drm_buddy_block_is_split(struct drm_buddy_block *block) +{ + return drm_buddy_block_state(block) == DRM_BUDDY_SPLIT; +} + +static inline u64 +drm_buddy_block_size(struct drm_buddy *mm, + struct drm_buddy_block *block) +{ + return mm->chunk_size << drm_buddy_block_order(block); +} + +int drm_buddy_init(struct drm_buddy *mm, u64 size, u64 chunk_size); + +void drm_buddy_fini(struct drm_buddy *mm); + +struct drm_buddy_block * +drm_get_buddy(struct drm_buddy_block *block); + +int drm_buddy_alloc_blocks(struct drm_buddy *mm, + u64 start, u64 end, u64 size, + u64 min_page_size, + struct list_head *blocks, + unsigned long flags); + +int drm_buddy_block_trim(struct drm_buddy *mm, + u64 *start, + u64 new_size, + struct list_head *blocks); + +void drm_buddy_reset_clear(struct drm_buddy *mm, bool is_clear); + +void drm_buddy_free_block(struct drm_buddy *mm, struct drm_buddy_block *block); + +void drm_buddy_free_list(struct drm_buddy *mm, + struct list_head *objects, + unsigned int flags); + +void drm_buddy_print(struct drm_buddy *mm, struct drm_printer *p); +void drm_buddy_block_print(struct drm_buddy *mm, + struct drm_buddy_block *block, + struct drm_printer *p); +#endif |