Port Intel buddy system manager to drm root folder Add CPU mappable/non-mappable region support to the drm buddy manager
Signed-off-by: Arunpravin <arunpravin.paneersel...@amd.com> --- drivers/gpu/drm/Makefile | 2 +- drivers/gpu/drm/drm_buddy.c | 465 ++++++++++++++++++++++++++++++++++++ include/drm/drm_buddy.h | 154 ++++++++++++ 3 files changed, 620 insertions(+), 1 deletion(-) create mode 100644 drivers/gpu/drm/drm_buddy.c create mode 100644 include/drm/drm_buddy.h diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index a118692a6df7..fe1a2fc09675 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -18,7 +18,7 @@ drm-y := drm_aperture.o drm_auth.o drm_cache.o \ drm_dumb_buffers.o drm_mode_config.o drm_vblank.o \ drm_syncobj.o drm_lease.o drm_writeback.o drm_client.o \ drm_client_modeset.o drm_atomic_uapi.o drm_hdcp.o \ - drm_managed.o drm_vblank_work.o + drm_managed.o drm_vblank_work.o drm_buddy.o drm-$(CONFIG_DRM_LEGACY) += drm_agpsupport.o drm_bufs.o drm_context.o drm_dma.o \ drm_legacy_misc.o drm_lock.o drm_memory.o drm_scatter.o \ diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c new file mode 100644 index 000000000000..f07919a004b6 --- /dev/null +++ b/drivers/gpu/drm/drm_buddy.c @@ -0,0 +1,465 @@ +// SPDX-License-Identifier: MIT +/* + * Copyright � 2021 Intel Corporation + */ + +#include <linux/kmemleak.h> +#include <drm/drm_buddy.h> + +static struct drm_buddy_block *drm_block_alloc(struct drm_buddy_mm *mm, + struct drm_buddy_block *parent, unsigned int order, + u64 offset) +{ + struct drm_buddy_block *block; + + BUG_ON(order > DRM_BUDDY_MAX_ORDER); + + block = kmem_cache_zalloc(mm->slab_blocks, GFP_KERNEL); + if (!block) + return NULL; + + block->header = offset; + block->header |= order; + block->parent = parent; + block->start = offset >> PAGE_SHIFT; + block->size = (mm->chunk_size << order) >> PAGE_SHIFT; + + BUG_ON(block->header & DRM_BUDDY_HEADER_UNUSED); + return block; +} + +static void drm_block_free(struct drm_buddy_mm *mm, struct drm_buddy_block *block) +{ + kmem_cache_free(mm->slab_blocks, block); +} + +static void add_ordered(struct drm_buddy_mm *mm, struct drm_buddy_block *block) +{ + struct drm_buddy_block *node; + + if (list_empty(&mm->free_list[drm_buddy_block_order(block)])) { + list_add(&block->link, + &mm->free_list[drm_buddy_block_order(block)]); + return; + } + + list_for_each_entry(node, &mm->free_list[drm_buddy_block_order(block)], link) + if (block->start > node->start) + break; + + __list_add(&block->link, node->link.prev, &node->link); +} + +static void mark_allocated(struct drm_buddy_block *block) +{ + block->header &= ~DRM_BUDDY_HEADER_STATE; + block->header |= DRM_BUDDY_ALLOCATED; + + list_del(&block->link); +} + +static void mark_free(struct drm_buddy_mm *mm, + struct drm_buddy_block *block) +{ + block->header &= ~DRM_BUDDY_HEADER_STATE; + block->header |= DRM_BUDDY_FREE; + + add_ordered(mm, block); +} + +static void mark_split(struct drm_buddy_block *block) +{ + block->header &= ~DRM_BUDDY_HEADER_STATE; + block->header |= DRM_BUDDY_SPLIT; + + list_del(&block->link); +} + +int drm_buddy_init(struct drm_buddy_mm *mm, u64 size, u64 chunk_size) +{ + unsigned int i; + u64 offset; + + if (size < chunk_size) + return -EINVAL; + + if (chunk_size < PAGE_SIZE) + return -EINVAL; + + if (!is_power_of_2(chunk_size)) + return -EINVAL; + + size = round_down(size, chunk_size); + + mm->size = size; + mm->chunk_size = chunk_size; + mm->max_order = ilog2(size) - ilog2(chunk_size); + + BUG_ON(mm->max_order > DRM_BUDDY_MAX_ORDER); + + mm->slab_blocks = KMEM_CACHE(drm_buddy_block, SLAB_HWCACHE_ALIGN); + + if (!mm->slab_blocks) + return -ENOMEM; + + mm->free_list = kmalloc_array(mm->max_order + 1, + sizeof(struct list_head), + GFP_KERNEL); + if (!mm->free_list) + goto out_destroy_slab; + + for (i = 0; i <= mm->max_order; ++i) + INIT_LIST_HEAD(&mm->free_list[i]); + + mm->n_roots = hweight64(size); + + mm->roots = kmalloc_array(mm->n_roots, + sizeof(struct drm_buddy_block *), + GFP_KERNEL); + if (!mm->roots) + goto out_free_list; + + offset = 0; + i = 0; + + /* + * Split into power-of-two blocks, in case we are given a size that is + * not itself a power-of-two. + */ + do { + struct drm_buddy_block *root; + unsigned int order; + u64 root_size; + + root_size = rounddown_pow_of_two(size); + order = ilog2(root_size) - ilog2(chunk_size); + + root = drm_block_alloc(mm, NULL, order, offset); + if (!root) + goto out_free_roots; + + mark_free(mm, root); + + BUG_ON(i > mm->max_order); + BUG_ON(drm_buddy_block_size(mm, root) < chunk_size); + + mm->roots[i] = root; + + offset += root_size; + size -= root_size; + i++; + } while (size); + + return 0; + +out_free_roots: + while (i--) + drm_block_free(mm, mm->roots[i]); + kfree(mm->roots); +out_free_list: + kfree(mm->free_list); +out_destroy_slab: + kmem_cache_destroy(mm->slab_blocks); + return -ENOMEM; +} +EXPORT_SYMBOL(drm_buddy_init); + +void drm_buddy_fini(struct drm_buddy_mm *mm) +{ + int i; + + for (i = 0; i < mm->n_roots; ++i) { + WARN_ON(!drm_buddy_block_is_free(mm->roots[i])); + drm_block_free(mm, mm->roots[i]); + } + + kfree(mm->roots); + kfree(mm->free_list); + kmem_cache_destroy(mm->slab_blocks); +} +EXPORT_SYMBOL(drm_buddy_fini); + +static int split_block(struct drm_buddy_mm *mm, + struct drm_buddy_block *block) +{ + unsigned int block_order = drm_buddy_block_order(block) - 1; + u64 offset = drm_buddy_block_offset(block); + + BUG_ON(!drm_buddy_block_is_free(block)); + BUG_ON(!drm_buddy_block_order(block)); + + block->left = drm_block_alloc(mm, block, block_order, offset); + if (!block->left) + return -ENOMEM; + + block->right = drm_block_alloc(mm, block, block_order, + offset + (mm->chunk_size << block_order)); + if (!block->right) { + drm_block_free(mm, block->left); + return -ENOMEM; + } + + mark_free(mm, block->left); + mark_free(mm, block->right); + + mark_split(block); + + return 0; +} + +static struct drm_buddy_block * +get_buddy(struct drm_buddy_block *block) +{ + struct drm_buddy_block *parent; + + parent = block->parent; + if (!parent) + return NULL; + + if (parent->left == block) + return parent->right; + + return parent->left; +} + +static void __drm_buddy_free(struct drm_buddy_mm *mm, + struct drm_buddy_block *block) +{ + struct drm_buddy_block *parent; + + while ((parent = block->parent)) { + struct drm_buddy_block *buddy; + + buddy = get_buddy(block); + + if (!drm_buddy_block_is_free(buddy)) + break; + + list_del(&buddy->link); + + drm_block_free(mm, block); + drm_block_free(mm, buddy); + + block = parent; + } + + mark_free(mm, block); +} + +void drm_buddy_free(struct drm_buddy_mm *mm, + struct drm_buddy_block *block) +{ + BUG_ON(!drm_buddy_block_is_allocated(block)); + __drm_buddy_free(mm, block); +} +EXPORT_SYMBOL(drm_buddy_free); + +void drm_buddy_free_list(struct drm_buddy_mm *mm, struct list_head *objects) +{ + struct drm_buddy_block *block, *on; + + list_for_each_entry_safe(block, on, objects, link) { + drm_buddy_free(mm, block); + cond_resched(); + } + INIT_LIST_HEAD(objects); +} +EXPORT_SYMBOL(drm_buddy_free_list); + +/* + * Allocate power-of-two block. The order value here translates to: + * + * 0 = 2^0 * mm->chunk_size + * 1 = 2^1 * mm->chunk_size + * 2 = 2^2 * mm->chunk_size + * ... + */ +struct drm_buddy_block * +drm_buddy_alloc(struct drm_buddy_mm *mm, unsigned int order, + bool bar_enabled, unsigned int limit, + enum drm_buddy_alloc_mode mode) +{ + struct drm_buddy_block *block = NULL; + unsigned int pages; + unsigned int i; + int err; + + pages = (mm->chunk_size << order) >> PAGE_SHIFT; + + for (i = order; i <= mm->max_order; ++i) { + if (mode == DRM_BUDDY_TOP_DOWN) { + if (!list_empty(&mm->free_list[i])) { + block = list_first_entry(&mm->free_list[i], + struct drm_buddy_block, link); + + if (bar_enabled) { + if (!(block->start > limit)) + continue; + } + + break; + } + } else if (mode == DRM_BUDDY_BOTTOM_UP) { + if (!list_empty(&mm->free_list[i])) { + block = list_last_entry(&mm->free_list[i], + struct drm_buddy_block, link); + + if (bar_enabled) { + if (!(block->start < limit && + (block->start + pages) < limit)) + continue; + } + + break; + } + } + } + + if (!block) + return ERR_PTR(-ENOSPC); + + BUG_ON(!drm_buddy_block_is_free(block)); + + while (i != order) { + err = split_block(mm, block); + if (unlikely(err)) + goto out_free; + + /* Go low */ + if (mode == DRM_BUDDY_TOP_DOWN) + block = block->right; + else + block = block->left; + i--; + } + + if (mode == DRM_BUDDY_TOP_DOWN && bar_enabled) { + if (!(block->start > limit)) + return ERR_PTR(-ENOSPC); + } else if (mode == DRM_BUDDY_BOTTOM_UP && bar_enabled) { + if (!(block->start < limit && + (block->start + pages) < limit)) + return ERR_PTR(-ENOSPC); + } + + mark_allocated(block); + kmemleak_update_trace(block); + return block; + +out_free: + if (i != order) + __drm_buddy_free(mm, block); + return ERR_PTR(err); +} +EXPORT_SYMBOL(drm_buddy_alloc); + +static inline bool overlaps(u64 s1, u64 e1, u64 s2, u64 e2) +{ + return s1 <= e2 && e1 >= s2; +} + +static inline bool contains(u64 s1, u64 e1, u64 s2, u64 e2) +{ + return s1 <= s2 && e1 >= e2; +} + +/* + * Allocate range. Note that it's safe to chain together multiple alloc_ranges + * with the same blocks list. + * + * Intended for pre-allocating portions of the address space, for example to + * reserve a block for the initial framebuffer or similar, hence the expectation + * here is that drm_buddy_alloc() is still the main vehicle for + * allocations, so if that's not the case then the drm_mm range allocator is + * probably a much better fit, and so you should probably go use that instead. + */ +int drm_buddy_alloc_range(struct drm_buddy_mm *mm, + struct list_head *blocks, + u64 start, u64 size) +{ + struct drm_buddy_block *block; + struct drm_buddy_block *buddy; + LIST_HEAD(allocated); + LIST_HEAD(dfs); + u64 end; + int err; + int i; + + if (size < mm->chunk_size) + return -EINVAL; + + if (!IS_ALIGNED(size | start, mm->chunk_size)) + return -EINVAL; + + if (range_overflows(start, size, mm->size)) + return -EINVAL; + + for (i = 0; i < mm->n_roots; ++i) + list_add_tail(&mm->roots[i]->tmp_link, &dfs); + + end = start + size - 1; + + do { + u64 block_start; + u64 block_end; + + block = list_first_entry_or_null(&dfs, + struct drm_buddy_block, + tmp_link); + if (!block) + break; + + list_del(&block->tmp_link); + + block_start = drm_buddy_block_offset(block); + block_end = block_start + drm_buddy_block_size(mm, block) - 1; + + if (!overlaps(start, end, block_start, block_end)) + continue; + + if (drm_buddy_block_is_allocated(block)) { + err = -ENOSPC; + goto err_free; + } + + if (contains(start, end, block_start, block_end)) { + if (!drm_buddy_block_is_free(block)) { + err = -ENOSPC; + goto err_free; + } + + mark_allocated(block); + list_add_tail(&block->link, &allocated); + continue; + } + + if (!drm_buddy_block_is_split(block)) { + err = split_block(mm, block); + if (unlikely(err)) + goto err_undo; + } + + list_add(&block->right->tmp_link, &dfs); + list_add(&block->left->tmp_link, &dfs); + } while (1); + + list_splice_tail(&allocated, blocks); + return 0; + +err_undo: + /* + * We really don't want to leave around a bunch of split blocks, since + * bigger is better, so make sure we merge everything back before we + * free the allocated blocks. + */ + buddy = get_buddy(block); + if (buddy && + (drm_buddy_block_is_free(block) && + drm_buddy_block_is_free(buddy))) + __drm_buddy_free(mm, block); + +err_free: + drm_buddy_free_list(mm, &allocated); + return err; +} +EXPORT_SYMBOL(drm_buddy_alloc_range); diff --git a/include/drm/drm_buddy.h b/include/drm/drm_buddy.h new file mode 100644 index 000000000000..50e4d819a3dd --- /dev/null +++ b/include/drm/drm_buddy.h @@ -0,0 +1,154 @@ +/* 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> + +#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__; \ +}) + +enum drm_buddy_alloc_mode { + DRM_BUDDY_TOP_DOWN = 0, + DRM_BUDDY_BOTTOM_UP, + DRM_BUDDY_ALLOC_RANGE +}; + +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; + /* Store start and size fields in pages */ + u64 start; + u64 size; + + 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_mm { + struct kmem_cache *slab_blocks; + /* 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; +}; + +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 *mm, + struct drm_buddy_block *block) +{ + return mm->chunk_size << drm_buddy_block_order(block); +} + +int drm_buddy_init(struct drm_buddy_mm *mm, u64 size, u64 chunk_size); + +void drm_buddy_fini(struct drm_buddy_mm *mm); + +struct drm_buddy_block * +drm_buddy_alloc(struct drm_buddy_mm *mm, unsigned int order, + bool bar_limit_enabled, unsigned int limit, + enum drm_buddy_alloc_mode mode); + +int drm_buddy_alloc_range(struct drm_buddy_mm *mm, + struct list_head *blocks, + u64 start, u64 size); + +void drm_buddy_free(struct drm_buddy_mm *mm, struct drm_buddy_block *block); + +void drm_buddy_free_list(struct drm_buddy_mm *mm, struct list_head *objects); + +#endif -- 2.25.1