linux_dsm_epyc7002/drivers/gpu/drm/i915/i915_buddy.h
Matthew Auld 14d1b9a624 drm/i915: buddy allocator
Simple buddy allocator. We want to allocate properly aligned
power-of-two blocks to promote usage of huge-pages for the GTT, so 64K,
2M and possibly even 1G. While we do support allocating stuff at a
specific offset, it is more intended for preallocating portions of the
address space, say for an initial framebuffer, for other uses drm_mm is
probably a much better fit. Anyway, hopefully this can all be thrown
away if we eventually move to having the core MM manage device memory.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190809202926.14545-2-matthew.auld@intel.com
2019-08-10 19:47:40 +01:00

129 lines
3.3 KiB
C

/* SPDX-License-Identifier: MIT */
/*
* Copyright © 2019 Intel Corporation
*/
#ifndef __I915_BUDDY_H__
#define __I915_BUDDY_H__
#include <linux/bitops.h>
#include <linux/list.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)
#define I915_BUDDY_HEADER_ORDER GENMASK_ULL(9, 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;
};
#define I915_BUDDY_MAX_ORDER I915_BUDDY_HEADER_ORDER
/*
* 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;
};
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);
#endif