[PATCH v4 1/6] drm: move the buddy allocator from i915 into common drm
Christian König
ckoenig.leichtzumerken at gmail.com
Thu Dec 2 08:03:14 UTC 2021
Am 01.12.21 um 17:39 schrieb Arunpravin:
> 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)
I only skimmed over this, but this looks really good now.
Only remaining problem is that you need to fix the build error reported
by the kernel robot in drivers/gpu/drm/i915/selftests/intel_memory_region.c.
I strongly suggest that you use a build test config with all DRM drivers
and selftests enabled to narrow down things like that before sending it
out. I can help with that if necessary.
Regards,
Christian.
>
> Signed-off-by: Arunpravin <Arunpravin.PaneerSelvam at amd.com>
> ---
> drivers/gpu/drm/Kconfig | 6 +
> drivers/gpu/drm/Makefile | 2 +
> drivers/gpu/drm/drm_buddy.c | 516 ++++++++++++++++++
> drivers/gpu/drm/i915/Kconfig | 1 +
> drivers/gpu/drm/i915/Makefile | 1 -
> drivers/gpu/drm/i915/i915_buddy.c | 466 ----------------
> drivers/gpu/drm/i915/i915_buddy.h | 143 -----
> drivers/gpu/drm/i915/i915_module.c | 3 -
> drivers/gpu/drm/i915/i915_scatterlist.c | 11 +-
> drivers/gpu/drm/i915/i915_ttm_buddy_manager.c | 33 +-
> drivers/gpu/drm/i915/i915_ttm_buddy_manager.h | 4 +-
> include/drm/drm_buddy.h | 154 ++++++
> 12 files changed, 703 insertions(+), 637 deletions(-)
> create mode 100644 drivers/gpu/drm/drm_buddy.c
> delete mode 100644 drivers/gpu/drm/i915/i915_buddy.c
> delete mode 100644 drivers/gpu/drm/i915/i915_buddy.h
> create mode 100644 include/drm/drm_buddy.h
>
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index 0039df26854b..7a4a66d54782 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -197,6 +197,12 @@ config DRM_TTM
> GPU memory types. Will be enabled automatically if a device driver
> uses it.
>
> +config DRM_BUDDY
> + tristate
> + depends on DRM
> + help
> + A page based buddy allocator
> +
> config DRM_VRAM_HELPER
> tristate
> depends on DRM
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index 0dff40bb863c..e62e432bf1e5 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -35,6 +35,8 @@ drm-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o
>
> obj-$(CONFIG_DRM_DP_AUX_BUS) += drm_dp_aux_bus.o
>
> +obj-$(CONFIG_DRM_BUDDY) += drm_buddy.o
> +
> drm_vram_helper-y := drm_gem_vram_helper.o
> obj-$(CONFIG_DRM_VRAM_HELPER) += drm_vram_helper.o
>
> diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c
> new file mode 100644
> index 000000000000..9340a4b61c5a
> --- /dev/null
> +++ b/drivers/gpu/drm/drm_buddy.c
> @@ -0,0 +1,516 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright © 2021 Intel Corporation
> + */
> +
> +#include <linux/kmemleak.h>
> +#include <linux/module.h>
> +#include <linux/sizes.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;
> +
> + 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 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;
> +
> + list_add(&block->link,
> + &mm->free_list[drm_buddy_block_order(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);
> +}
> +
> +/**
> + * drm_buddy_init - init memory manager
> + *
> + * @mm: DRM buddy manager to initialize
> + * @size: size in bytes to manage
> + * @chunk_size: minimum page size in bytes for our allocations
> + *
> + * Initializes the memory manager and its resources.
> + *
> + * Returns:
> + * 0 on success, error code on failure.
> + */
> +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->avail = 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, 0);
> + 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);
> +
> +/**
> + * drm_buddy_fini - tear down the memory manager
> + *
> + * @mm: DRM buddy manager to free
> + *
> + * Cleanup memory manager resources and the freelist
> + */
> +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]);
> + }
> +
> + WARN_ON(mm->avail != mm->size);
> +
> + 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));
> + mm->avail += drm_buddy_block_size(mm, block);
> + __drm_buddy_free(mm, block);
> +}
> +
> +/**
> + * drm_buddy_free_list - free blocks
> + *
> + * @mm: DRM buddy manager
> + * @objects: input list head to free blocks
> + */
> +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);
> +
> +/**
> + * drm_buddy_alloc - allocate power-of-two blocks
> + *
> + * @mm: DRM buddy manager to allocate from
> + * @order: size of the allocation
> + *
> + * The order value here translates to:
> + *
> + * 0 = 2^0 * mm->chunk_size
> + * 1 = 2^1 * mm->chunk_size
> + * 2 = 2^2 * mm->chunk_size
> + *
> + * Returns:
> + * allocated ptr to the &drm_buddy_block on success
> + */
> +struct drm_buddy_block *
> +drm_buddy_alloc(struct drm_buddy_mm *mm, unsigned int order)
> +{
> + struct drm_buddy_block *block = NULL;
> + unsigned int i;
> + int err;
> +
> + for (i = order; i <= mm->max_order; ++i) {
> + block = list_first_entry_or_null(&mm->free_list[i],
> + struct drm_buddy_block,
> + link);
> + if (block)
> + 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 */
> + block = block->left;
> + i--;
> + }
> +
> + mark_allocated(block);
> + mm->avail -= drm_buddy_block_size(mm, 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;
> +}
> +
> +/**
> + * drm_buddy_alloc_range - allocate range
> + *
> + * @mm: DRM buddy manager to allocate from
> + * @blocks: output list head to add allocated blocks
> + * @start: start of the allowed range for this block
> + * @size: size of the allocation
> + *
> + * 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.
> + *
> + * Note that it's safe to chain together multiple alloc_ranges
> + * with the same blocks list
> + *
> + * Returns:
> + * 0 on success, error code on failure.
> + */
> +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);
> + mm->avail -= drm_buddy_block_size(mm, 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);
> +
> +/**
> + * drm_buddy_block_print - print block information
> + *
> + * @mm: DRM buddy manager
> + * @block: DRM buddy block
> + * @p: DRM printer to use
> + */
> +void drm_buddy_block_print(struct drm_buddy_mm *mm,
> + struct drm_buddy_block *block,
> + struct drm_printer *p)
> +{
> + u64 start = drm_buddy_block_offset(block);
> + u64 size = drm_buddy_block_size(mm, block);
> +
> + drm_printf(p, "%#018llx-%#018llx: %llu\n", start, start + size, size);
> +}
> +EXPORT_SYMBOL(drm_buddy_block_print);
> +
> +/**
> + * drm_buddy_print - print allocator state
> + *
> + * @mm: DRM buddy manager
> + * @p: DRM printer to use
> + */
> +void drm_buddy_print(struct drm_buddy_mm *mm, struct drm_printer *p)
> +{
> + int order;
> +
> + drm_printf(p, "chunk_size: %lluKiB, total: %lluMiB, free: %lluMiB\n",
> + mm->chunk_size >> 10, mm->size >> 20, mm->avail >> 20);
> +
> + for (order = mm->max_order; order >= 0; order--) {
> + struct drm_buddy_block *block;
> + u64 count = 0, free;
> +
> + list_for_each_entry(block, &mm->free_list[order], link) {
> + BUG_ON(!drm_buddy_block_is_free(block));
> + count++;
> + }
> +
> + drm_printf(p, "order-%d ", order);
> +
> + free = count * (mm->chunk_size << order);
> + if (free < SZ_1M)
> + drm_printf(p, "free: %lluKiB", free >> 10);
> + else
> + drm_printf(p, "free: %lluMiB", free >> 20);
> +
> + drm_printf(p, ", pages: %llu\n", count);
> + }
> +}
> +EXPORT_SYMBOL(drm_buddy_print);
> +
> +MODULE_DESCRIPTION("DRM Buddy Allocator");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig
> index a4c94dc2e216..64b5e0a44d4c 100644
> --- a/drivers/gpu/drm/i915/Kconfig
> +++ b/drivers/gpu/drm/i915/Kconfig
> @@ -27,6 +27,7 @@ config DRM_I915
> select CEC_CORE if CEC_NOTIFIER
> select VMAP_PFN
> select DRM_TTM
> + select DRM_BUDDY
> help
> Choose this option if you have a system that has "Intel Graphics
> Media Accelerator" or "HD Graphics" integrated graphics,
> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> index 568d711a3537..a5a0fb33c897 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -161,7 +161,6 @@ gem-y += \
> i915-y += \
> $(gem-y) \
> i915_active.o \
> - i915_buddy.o \
> i915_cmd_parser.o \
> i915_gem_evict.o \
> i915_gem_gtt.o \
> diff --git a/drivers/gpu/drm/i915/i915_buddy.c b/drivers/gpu/drm/i915/i915_buddy.c
> deleted file mode 100644
> index 6e2ad68f8f3f..000000000000
> --- a/drivers/gpu/drm/i915/i915_buddy.c
> +++ /dev/null
> @@ -1,466 +0,0 @@
> -// SPDX-License-Identifier: MIT
> -/*
> - * Copyright © 2021 Intel Corporation
> - */
> -
> -#include <linux/kmemleak.h>
> -#include <linux/sizes.h>
> -
> -#include "i915_buddy.h"
> -
> -#include "i915_gem.h"
> -#include "i915_utils.h"
> -
> -static struct kmem_cache *slab_blocks;
> -
> -static struct i915_buddy_block *i915_block_alloc(struct i915_buddy_mm *mm,
> - struct i915_buddy_block *parent,
> - unsigned int order,
> - u64 offset)
> -{
> - struct i915_buddy_block *block;
> -
> - GEM_BUG_ON(order > I915_BUDDY_MAX_ORDER);
> -
> - block = kmem_cache_zalloc(slab_blocks, GFP_KERNEL);
> - if (!block)
> - return NULL;
> -
> - block->header = offset;
> - block->header |= order;
> - block->parent = parent;
> -
> - GEM_BUG_ON(block->header & I915_BUDDY_HEADER_UNUSED);
> - return block;
> -}
> -
> -static void i915_block_free(struct i915_buddy_mm *mm,
> - struct i915_buddy_block *block)
> -{
> - kmem_cache_free(slab_blocks, block);
> -}
> -
> -static void mark_allocated(struct i915_buddy_block *block)
> -{
> - block->header &= ~I915_BUDDY_HEADER_STATE;
> - block->header |= I915_BUDDY_ALLOCATED;
> -
> - list_del(&block->link);
> -}
> -
> -static void mark_free(struct i915_buddy_mm *mm,
> - struct i915_buddy_block *block)
> -{
> - block->header &= ~I915_BUDDY_HEADER_STATE;
> - block->header |= I915_BUDDY_FREE;
> -
> - list_add(&block->link,
> - &mm->free_list[i915_buddy_block_order(block)]);
> -}
> -
> -static void mark_split(struct i915_buddy_block *block)
> -{
> - block->header &= ~I915_BUDDY_HEADER_STATE;
> - block->header |= I915_BUDDY_SPLIT;
> -
> - list_del(&block->link);
> -}
> -
> -int i915_buddy_init(struct i915_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->avail = size;
> - mm->chunk_size = chunk_size;
> - mm->max_order = ilog2(size) - ilog2(chunk_size);
> -
> - GEM_BUG_ON(mm->max_order > I915_BUDDY_MAX_ORDER);
> -
> - mm->free_list = kmalloc_array(mm->max_order + 1,
> - sizeof(struct list_head),
> - GFP_KERNEL);
> - if (!mm->free_list)
> - return -ENOMEM;
> -
> - 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 i915_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 i915_buddy_block *root;
> - unsigned int order;
> - u64 root_size;
> -
> - root_size = rounddown_pow_of_two(size);
> - order = ilog2(root_size) - ilog2(chunk_size);
> -
> - root = i915_block_alloc(mm, NULL, order, offset);
> - if (!root)
> - goto out_free_roots;
> -
> - mark_free(mm, root);
> -
> - GEM_BUG_ON(i > mm->max_order);
> - GEM_BUG_ON(i915_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--)
> - i915_block_free(mm, mm->roots[i]);
> - kfree(mm->roots);
> -out_free_list:
> - kfree(mm->free_list);
> - return -ENOMEM;
> -}
> -
> -void i915_buddy_fini(struct i915_buddy_mm *mm)
> -{
> - int i;
> -
> - for (i = 0; i < mm->n_roots; ++i) {
> - GEM_WARN_ON(!i915_buddy_block_is_free(mm->roots[i]));
> - i915_block_free(mm, mm->roots[i]);
> - }
> -
> - GEM_WARN_ON(mm->avail != mm->size);
> -
> - kfree(mm->roots);
> - kfree(mm->free_list);
> -}
> -
> -static int split_block(struct i915_buddy_mm *mm,
> - struct i915_buddy_block *block)
> -{
> - unsigned int block_order = i915_buddy_block_order(block) - 1;
> - u64 offset = i915_buddy_block_offset(block);
> -
> - GEM_BUG_ON(!i915_buddy_block_is_free(block));
> - GEM_BUG_ON(!i915_buddy_block_order(block));
> -
> - block->left = i915_block_alloc(mm, block, block_order, offset);
> - if (!block->left)
> - return -ENOMEM;
> -
> - block->right = i915_block_alloc(mm, block, block_order,
> - offset + (mm->chunk_size << block_order));
> - if (!block->right) {
> - i915_block_free(mm, block->left);
> - return -ENOMEM;
> - }
> -
> - mark_free(mm, block->left);
> - mark_free(mm, block->right);
> -
> - mark_split(block);
> -
> - return 0;
> -}
> -
> -static struct i915_buddy_block *
> -get_buddy(struct i915_buddy_block *block)
> -{
> - struct i915_buddy_block *parent;
> -
> - parent = block->parent;
> - if (!parent)
> - return NULL;
> -
> - if (parent->left == block)
> - return parent->right;
> -
> - return parent->left;
> -}
> -
> -static void __i915_buddy_free(struct i915_buddy_mm *mm,
> - struct i915_buddy_block *block)
> -{
> - struct i915_buddy_block *parent;
> -
> - while ((parent = block->parent)) {
> - struct i915_buddy_block *buddy;
> -
> - buddy = get_buddy(block);
> -
> - if (!i915_buddy_block_is_free(buddy))
> - break;
> -
> - list_del(&buddy->link);
> -
> - i915_block_free(mm, block);
> - i915_block_free(mm, buddy);
> -
> - block = parent;
> - }
> -
> - mark_free(mm, block);
> -}
> -
> -void i915_buddy_free(struct i915_buddy_mm *mm,
> - struct i915_buddy_block *block)
> -{
> - GEM_BUG_ON(!i915_buddy_block_is_allocated(block));
> - mm->avail += i915_buddy_block_size(mm, block);
> - __i915_buddy_free(mm, block);
> -}
> -
> -void i915_buddy_free_list(struct i915_buddy_mm *mm, struct list_head *objects)
> -{
> - struct i915_buddy_block *block, *on;
> -
> - list_for_each_entry_safe(block, on, objects, link) {
> - i915_buddy_free(mm, block);
> - cond_resched();
> - }
> - INIT_LIST_HEAD(objects);
> -}
> -
> -/*
> - * 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 i915_buddy_block *
> -i915_buddy_alloc(struct i915_buddy_mm *mm, unsigned int order)
> -{
> - struct i915_buddy_block *block = NULL;
> - unsigned int i;
> - int err;
> -
> - for (i = order; i <= mm->max_order; ++i) {
> - block = list_first_entry_or_null(&mm->free_list[i],
> - struct i915_buddy_block,
> - link);
> - if (block)
> - break;
> - }
> -
> - if (!block)
> - return ERR_PTR(-ENOSPC);
> -
> - GEM_BUG_ON(!i915_buddy_block_is_free(block));
> -
> - while (i != order) {
> - err = split_block(mm, block);
> - if (unlikely(err))
> - goto out_free;
> -
> - /* Go low */
> - block = block->left;
> - i--;
> - }
> -
> - mark_allocated(block);
> - mm->avail -= i915_buddy_block_size(mm, block);
> - kmemleak_update_trace(block);
> - return block;
> -
> -out_free:
> - if (i != order)
> - __i915_buddy_free(mm, block);
> - return ERR_PTR(err);
> -}
> -
> -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 i915_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 i915_buddy_alloc_range(struct i915_buddy_mm *mm,
> - struct list_head *blocks,
> - u64 start, u64 size)
> -{
> - struct i915_buddy_block *block;
> - struct i915_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 i915_buddy_block,
> - tmp_link);
> - if (!block)
> - break;
> -
> - list_del(&block->tmp_link);
> -
> - block_start = i915_buddy_block_offset(block);
> - block_end = block_start + i915_buddy_block_size(mm, block) - 1;
> -
> - if (!overlaps(start, end, block_start, block_end))
> - continue;
> -
> - if (i915_buddy_block_is_allocated(block)) {
> - err = -ENOSPC;
> - goto err_free;
> - }
> -
> - if (contains(start, end, block_start, block_end)) {
> - if (!i915_buddy_block_is_free(block)) {
> - err = -ENOSPC;
> - goto err_free;
> - }
> -
> - mark_allocated(block);
> - mm->avail -= i915_buddy_block_size(mm, block);
> - list_add_tail(&block->link, &allocated);
> - continue;
> - }
> -
> - if (!i915_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 &&
> - (i915_buddy_block_is_free(block) &&
> - i915_buddy_block_is_free(buddy)))
> - __i915_buddy_free(mm, block);
> -
> -err_free:
> - i915_buddy_free_list(mm, &allocated);
> - return err;
> -}
> -
> -void i915_buddy_block_print(struct i915_buddy_mm *mm,
> - struct i915_buddy_block *block,
> - struct drm_printer *p)
> -{
> - u64 start = i915_buddy_block_offset(block);
> - u64 size = i915_buddy_block_size(mm, block);
> -
> - drm_printf(p, "%#018llx-%#018llx: %llu\n", start, start + size, size);
> -}
> -
> -void i915_buddy_print(struct i915_buddy_mm *mm, struct drm_printer *p)
> -{
> - int order;
> -
> - drm_printf(p, "chunk_size: %lluKiB, total: %lluMiB, free: %lluMiB\n",
> - mm->chunk_size >> 10, mm->size >> 20, mm->avail >> 20);
> -
> - for (order = mm->max_order; order >= 0; order--) {
> - struct i915_buddy_block *block;
> - u64 count = 0, free;
> -
> - list_for_each_entry(block, &mm->free_list[order], link) {
> - GEM_BUG_ON(!i915_buddy_block_is_free(block));
> - count++;
> - }
> -
> - drm_printf(p, "order-%d ", order);
> -
> - free = count * (mm->chunk_size << order);
> - if (free < SZ_1M)
> - drm_printf(p, "free: %lluKiB", free >> 10);
> - else
> - drm_printf(p, "free: %lluMiB", free >> 20);
> -
> - drm_printf(p, ", pages: %llu\n", count);
> - }
> -}
> -
> -#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
> -#include "selftests/i915_buddy.c"
> -#endif
> -
> -void i915_buddy_module_exit(void)
> -{
> - kmem_cache_destroy(slab_blocks);
> -}
> -
> -int __init i915_buddy_module_init(void)
> -{
> - slab_blocks = KMEM_CACHE(i915_buddy_block, 0);
> - if (!slab_blocks)
> - return -ENOMEM;
> -
> - return 0;
> -}
> diff --git a/drivers/gpu/drm/i915/i915_buddy.h b/drivers/gpu/drm/i915/i915_buddy.h
> deleted file mode 100644
> index 7077742112ac..000000000000
> --- a/drivers/gpu/drm/i915/i915_buddy.h
> +++ /dev/null
> @@ -1,143 +0,0 @@
> -/* SPDX-License-Identifier: MIT */
> -/*
> - * Copyright © 2021 Intel Corporation
> - */
> -
> -#ifndef __I915_BUDDY_H__
> -#define __I915_BUDDY_H__
> -
> -#include <linux/bitops.h>
> -#include <linux/list.h>
> -#include <linux/slab.h>
> -
> -#include <drm/drm_print.h>
> -
> -struct i915_buddy_block {
> -#define I915_BUDDY_HEADER_OFFSET GENMASK_ULL(63, 12)
> -#define I915_BUDDY_HEADER_STATE GENMASK_ULL(11, 10)
> -#define I915_BUDDY_ALLOCATED (1 << 10)
> -#define I915_BUDDY_FREE (2 << 10)
> -#define I915_BUDDY_SPLIT (3 << 10)
> -/* Free to be used, if needed in the future */
> -#define I915_BUDDY_HEADER_UNUSED GENMASK_ULL(9, 6)
> -#define I915_BUDDY_HEADER_ORDER GENMASK_ULL(5, 0)
> - u64 header;
> -
> - struct i915_buddy_block *left;
> - struct i915_buddy_block *right;
> - struct i915_buddy_block *parent;
> -
> - void *private; /* owned by creator */
> -
> - /*
> - * While the block is allocated by the user through i915_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
> - * i915_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 I915_BUDDY_MAX_ORDER (63 - PAGE_SHIFT)
> -
> -/*
> - * Binary Buddy System.
> - *
> - * Locking should be handled by the user, a simple mutex around
> - * i915_buddy_alloc* and i915_buddy_free* should suffice.
> - */
> -struct i915_buddy_mm {
> - /* 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 i915_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
> -i915_buddy_block_offset(struct i915_buddy_block *block)
> -{
> - return block->header & I915_BUDDY_HEADER_OFFSET;
> -}
> -
> -static inline unsigned int
> -i915_buddy_block_order(struct i915_buddy_block *block)
> -{
> - return block->header & I915_BUDDY_HEADER_ORDER;
> -}
> -
> -static inline unsigned int
> -i915_buddy_block_state(struct i915_buddy_block *block)
> -{
> - return block->header & I915_BUDDY_HEADER_STATE;
> -}
> -
> -static inline bool
> -i915_buddy_block_is_allocated(struct i915_buddy_block *block)
> -{
> - return i915_buddy_block_state(block) == I915_BUDDY_ALLOCATED;
> -}
> -
> -static inline bool
> -i915_buddy_block_is_free(struct i915_buddy_block *block)
> -{
> - return i915_buddy_block_state(block) == I915_BUDDY_FREE;
> -}
> -
> -static inline bool
> -i915_buddy_block_is_split(struct i915_buddy_block *block)
> -{
> - return i915_buddy_block_state(block) == I915_BUDDY_SPLIT;
> -}
> -
> -static inline u64
> -i915_buddy_block_size(struct i915_buddy_mm *mm,
> - struct i915_buddy_block *block)
> -{
> - return mm->chunk_size << i915_buddy_block_order(block);
> -}
> -
> -int i915_buddy_init(struct i915_buddy_mm *mm, u64 size, u64 chunk_size);
> -
> -void i915_buddy_fini(struct i915_buddy_mm *mm);
> -
> -struct i915_buddy_block *
> -i915_buddy_alloc(struct i915_buddy_mm *mm, unsigned int order);
> -
> -int i915_buddy_alloc_range(struct i915_buddy_mm *mm,
> - struct list_head *blocks,
> - u64 start, u64 size);
> -
> -void i915_buddy_free(struct i915_buddy_mm *mm, struct i915_buddy_block *block);
> -
> -void i915_buddy_free_list(struct i915_buddy_mm *mm, struct list_head *objects);
> -
> -void i915_buddy_print(struct i915_buddy_mm *mm, struct drm_printer *p);
> -void i915_buddy_block_print(struct i915_buddy_mm *mm,
> - struct i915_buddy_block *block,
> - struct drm_printer *p);
> -
> -void i915_buddy_module_exit(void);
> -int i915_buddy_module_init(void);
> -
> -#endif
> diff --git a/drivers/gpu/drm/i915/i915_module.c b/drivers/gpu/drm/i915/i915_module.c
> index c7507266aa83..355681dbd7a8 100644
> --- a/drivers/gpu/drm/i915/i915_module.c
> +++ b/drivers/gpu/drm/i915/i915_module.c
> @@ -9,7 +9,6 @@
> #include "gem/i915_gem_context.h"
> #include "gem/i915_gem_object.h"
> #include "i915_active.h"
> -#include "i915_buddy.h"
> #include "i915_params.h"
> #include "i915_pci.h"
> #include "i915_perf.h"
> @@ -50,8 +49,6 @@ static const struct {
> { .init = i915_check_nomodeset },
> { .init = i915_active_module_init,
> .exit = i915_active_module_exit },
> - { .init = i915_buddy_module_init,
> - .exit = i915_buddy_module_exit },
> { .init = i915_context_module_init,
> .exit = i915_context_module_exit },
> { .init = i915_gem_context_module_init,
> diff --git a/drivers/gpu/drm/i915/i915_scatterlist.c b/drivers/gpu/drm/i915/i915_scatterlist.c
> index 4a6712dca838..84d622aa32d2 100644
> --- a/drivers/gpu/drm/i915/i915_scatterlist.c
> +++ b/drivers/gpu/drm/i915/i915_scatterlist.c
> @@ -5,10 +5,9 @@
> */
>
> #include "i915_scatterlist.h"
> -
> -#include "i915_buddy.h"
> #include "i915_ttm_buddy_manager.h"
>
> +#include <drm/drm_buddy.h>
> #include <drm/drm_mm.h>
>
> #include <linux/slab.h>
> @@ -126,9 +125,9 @@ struct sg_table *i915_sg_from_buddy_resource(struct ttm_resource *res,
> struct i915_ttm_buddy_resource *bman_res = to_ttm_buddy_resource(res);
> const u64 size = res->num_pages << PAGE_SHIFT;
> const u64 max_segment = rounddown(UINT_MAX, PAGE_SIZE);
> - struct i915_buddy_mm *mm = bman_res->mm;
> + struct drm_buddy_mm *mm = bman_res->mm;
> struct list_head *blocks = &bman_res->blocks;
> - struct i915_buddy_block *block;
> + struct drm_buddy_block *block;
> struct scatterlist *sg;
> struct sg_table *st;
> resource_size_t prev_end;
> @@ -151,8 +150,8 @@ struct sg_table *i915_sg_from_buddy_resource(struct ttm_resource *res,
> list_for_each_entry(block, blocks, link) {
> u64 block_size, offset;
>
> - block_size = min_t(u64, size, i915_buddy_block_size(mm, block));
> - offset = i915_buddy_block_offset(block);
> + block_size = min_t(u64, size, drm_buddy_block_size(mm, block));
> + offset = drm_buddy_block_offset(block);
>
> while (block_size) {
> u64 len;
> diff --git a/drivers/gpu/drm/i915/i915_ttm_buddy_manager.c b/drivers/gpu/drm/i915/i915_ttm_buddy_manager.c
> index d59fbb019032..c4b70cb8c248 100644
> --- a/drivers/gpu/drm/i915/i915_ttm_buddy_manager.c
> +++ b/drivers/gpu/drm/i915/i915_ttm_buddy_manager.c
> @@ -8,14 +8,15 @@
> #include <drm/ttm/ttm_bo_driver.h>
> #include <drm/ttm/ttm_placement.h>
>
> +#include <drm/drm_buddy.h>
> +
> #include "i915_ttm_buddy_manager.h"
>
> -#include "i915_buddy.h"
> #include "i915_gem.h"
>
> struct i915_ttm_buddy_manager {
> struct ttm_resource_manager manager;
> - struct i915_buddy_mm mm;
> + struct drm_buddy_mm mm;
> struct list_head reserved;
> struct mutex lock;
> u64 default_page_size;
> @@ -34,7 +35,7 @@ static int i915_ttm_buddy_man_alloc(struct ttm_resource_manager *man,
> {
> struct i915_ttm_buddy_manager *bman = to_buddy_manager(man);
> struct i915_ttm_buddy_resource *bman_res;
> - struct i915_buddy_mm *mm = &bman->mm;
> + struct drm_buddy_mm *mm = &bman->mm;
> unsigned long n_pages;
> unsigned int min_order;
> u64 min_page_size;
> @@ -73,7 +74,7 @@ static int i915_ttm_buddy_man_alloc(struct ttm_resource_manager *man,
> n_pages = size >> ilog2(mm->chunk_size);
>
> do {
> - struct i915_buddy_block *block;
> + struct drm_buddy_block *block;
> unsigned int order;
>
> order = fls(n_pages) - 1;
> @@ -82,7 +83,7 @@ static int i915_ttm_buddy_man_alloc(struct ttm_resource_manager *man,
>
> do {
> mutex_lock(&bman->lock);
> - block = i915_buddy_alloc(mm, order);
> + block = drm_buddy_alloc(mm, order);
> mutex_unlock(&bman->lock);
> if (!IS_ERR(block))
> break;
> @@ -106,7 +107,7 @@ static int i915_ttm_buddy_man_alloc(struct ttm_resource_manager *man,
>
> err_free_blocks:
> mutex_lock(&bman->lock);
> - i915_buddy_free_list(mm, &bman_res->blocks);
> + drm_buddy_free_list(mm, &bman_res->blocks);
> mutex_unlock(&bman->lock);
> err_free_res:
> kfree(bman_res);
> @@ -120,7 +121,7 @@ static void i915_ttm_buddy_man_free(struct ttm_resource_manager *man,
> struct i915_ttm_buddy_manager *bman = to_buddy_manager(man);
>
> mutex_lock(&bman->lock);
> - i915_buddy_free_list(&bman->mm, &bman_res->blocks);
> + drm_buddy_free_list(&bman->mm, &bman_res->blocks);
> mutex_unlock(&bman->lock);
>
> kfree(bman_res);
> @@ -130,17 +131,17 @@ static void i915_ttm_buddy_man_debug(struct ttm_resource_manager *man,
> struct drm_printer *printer)
> {
> struct i915_ttm_buddy_manager *bman = to_buddy_manager(man);
> - struct i915_buddy_block *block;
> + struct drm_buddy_block *block;
>
> mutex_lock(&bman->lock);
> drm_printf(printer, "default_page_size: %lluKiB\n",
> bman->default_page_size >> 10);
>
> - i915_buddy_print(&bman->mm, printer);
> + drm_buddy_print(&bman->mm, printer);
>
> drm_printf(printer, "reserved:\n");
> list_for_each_entry(block, &bman->reserved, link)
> - i915_buddy_block_print(&bman->mm, block, printer);
> + drm_buddy_block_print(&bman->mm, block, printer);
> mutex_unlock(&bman->lock);
> }
>
> @@ -190,7 +191,7 @@ int i915_ttm_buddy_man_init(struct ttm_device *bdev,
> if (!bman)
> return -ENOMEM;
>
> - err = i915_buddy_init(&bman->mm, size, chunk_size);
> + err = drm_buddy_init(&bman->mm, size, chunk_size);
> if (err)
> goto err_free_bman;
>
> @@ -228,7 +229,7 @@ int i915_ttm_buddy_man_fini(struct ttm_device *bdev, unsigned int type)
> {
> struct ttm_resource_manager *man = ttm_manager_type(bdev, type);
> struct i915_ttm_buddy_manager *bman = to_buddy_manager(man);
> - struct i915_buddy_mm *mm = &bman->mm;
> + struct drm_buddy_mm *mm = &bman->mm;
> int ret;
>
> ttm_resource_manager_set_used(man, false);
> @@ -240,8 +241,8 @@ int i915_ttm_buddy_man_fini(struct ttm_device *bdev, unsigned int type)
> ttm_set_driver_manager(bdev, type, NULL);
>
> mutex_lock(&bman->lock);
> - i915_buddy_free_list(mm, &bman->reserved);
> - i915_buddy_fini(mm);
> + drm_buddy_free_list(mm, &bman->reserved);
> + drm_buddy_fini(mm);
> mutex_unlock(&bman->lock);
>
> ttm_resource_manager_cleanup(man);
> @@ -264,11 +265,11 @@ int i915_ttm_buddy_man_reserve(struct ttm_resource_manager *man,
> u64 start, u64 size)
> {
> struct i915_ttm_buddy_manager *bman = to_buddy_manager(man);
> - struct i915_buddy_mm *mm = &bman->mm;
> + struct drm_buddy_mm *mm = &bman->mm;
> int ret;
>
> mutex_lock(&bman->lock);
> - ret = i915_buddy_alloc_range(mm, &bman->reserved, start, size);
> + ret = drm_buddy_alloc_range(mm, &bman->reserved, start, size);
> mutex_unlock(&bman->lock);
>
> return ret;
> diff --git a/drivers/gpu/drm/i915/i915_ttm_buddy_manager.h b/drivers/gpu/drm/i915/i915_ttm_buddy_manager.h
> index 0722d33f3e14..fa644b512c2e 100644
> --- a/drivers/gpu/drm/i915/i915_ttm_buddy_manager.h
> +++ b/drivers/gpu/drm/i915/i915_ttm_buddy_manager.h
> @@ -13,7 +13,7 @@
>
> struct ttm_device;
> struct ttm_resource_manager;
> -struct i915_buddy_mm;
> +struct drm_buddy_mm;
>
> /**
> * struct i915_ttm_buddy_resource
> @@ -28,7 +28,7 @@ struct i915_buddy_mm;
> struct i915_ttm_buddy_resource {
> struct ttm_resource base;
> struct list_head blocks;
> - struct i915_buddy_mm *mm;
> + struct drm_buddy_mm *mm;
> };
>
> /**
> diff --git a/include/drm/drm_buddy.h b/include/drm/drm_buddy.h
> new file mode 100644
> index 000000000000..f9ff48a3f3a6
> --- /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>
> +
> +#include <drm/drm_print.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__; \
> +})
> +
> +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_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;
> + 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 *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);
> +
> +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);
> +
> +void drm_buddy_print(struct drm_buddy_mm *mm, struct drm_printer *p);
> +void drm_buddy_block_print(struct drm_buddy_mm *mm,
> + struct drm_buddy_block *block,
> + struct drm_printer *p);
> +
> +void drm_buddy_module_exit(void);
> +int drm_buddy_module_init(void);
> +
> +#endif
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