From 6387a3c4b0c45a3932cc06daaf15727e7f83be43 Mon Sep 17 00:00:00 2001 From: Arunpravin Date: Tue, 18 Jan 2022 16:14:59 +0530 Subject: drm: move the buddy allocator from i915 into common drm MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Move the base i915 buddy allocator code into drm - Move i915_buddy.h to include/drm - Move i915_buddy.c to drm root folder - Rename "i915" string with "drm" string wherever applicable - Rename "I915" string with "DRM" string wherever applicable - Fix header file dependencies - Fix alignment issues - add Makefile support for drm buddy - export functions and write kerneldoc description - Remove i915 selftest config check condition as buddy selftest will be moved to drm selftest folder cleanup i915 buddy references in i915 driver module and replace with drm buddy v2: - include header file in alphabetical order(Thomas) - merged changes listed in the body section into a single patch to keep the build intact(Christian, Jani) v3: - make drm buddy a separate module(Thomas, Christian) v4: - Fix build error reported by kernel test robot - removed i915 buddy selftest from i915_mock_selftests.h to avoid build error - removed selftests/i915_buddy.c file as we create a new set of buddy test cases in drm/selftests folder v5: - Fix merge conflict issue v6: - replace drm_buddy_mm structure name as drm_buddy(Thomas, Christian) - replace drm_buddy_alloc() function name as drm_buddy_alloc_blocks() (Thomas) - replace drm_buddy_free() function name as drm_buddy_free_block() (Thomas) - export drm_buddy_free_block() function - fix multiple instances of KMEM_CACHE() entry v7: - fix warnings reported by kernel test robot - modify the license(Christian) v8: - fix warnings reported by kernel test robot Signed-off-by: Arunpravin Acked-by: Christian König Link: https://patchwork.freedesktop.org/patch/msgid/20220118104504.2349-1-Arunpravin.PaneerSelvam@amd.com Signed-off-by: Christian König --- include/drm/drm_buddy.h | 150 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 150 insertions(+) create mode 100644 include/drm/drm_buddy.h (limited to 'include/drm/drm_buddy.h') diff --git a/include/drm/drm_buddy.h b/include/drm/drm_buddy.h new file mode 100644 index 000000000000..f524db152413 --- /dev/null +++ b/include/drm/drm_buddy.h @@ -0,0 +1,150 @@ +/* SPDX-License-Identifier: MIT */ +/* + * Copyright © 2021 Intel Corporation + */ + +#ifndef __DRM_BUDDY_H__ +#define __DRM_BUDDY_H__ + +#include +#include +#include +#include + +#include + +#define range_overflows(start, size, max) ({ \ + typeof(start) start__ = (start); \ + typeof(size) size__ = (size); \ + typeof(max) max__ = (max); \ + (void)(&start__ == &size__); \ + (void)(&start__ == &max__); \ + start__ >= max__ || size__ > max__ - start__; \ +}) + +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) +/* Free to be used, if needed in the future */ +#define DRM_BUDDY_HEADER_UNUSED GENMASK_ULL(9, 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. + */ + struct list_head link; + struct list_head tmp_link; +}; + +/* Order-zero must be at least PAGE_SIZE */ +#define DRM_BUDDY_MAX_ORDER (63 - PAGE_SHIFT) + +/* + * 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 list_head *free_list; + + /* + * 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 PAGE_SIZE */ + u64 chunk_size; + u64 size; + u64 avail; +}; + +static inline u64 +drm_buddy_block_offset(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_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_buddy_alloc_blocks(struct drm_buddy *mm, unsigned int order); + +int drm_buddy_alloc_range(struct drm_buddy *mm, + struct list_head *blocks, + u64 start, u64 size); + +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); + +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 -- cgit v1.2.3