i915_ttm_buddy_manager.c | Explore in Territory

// SPDX-License-Identifier: MIT
/*
 * Copyright © 2021 Intel Corporation
 */

#include <linux/slab.h>

#include <drm/ttm/ttm_placement.h>
#include <drm/ttm/ttm_bo.h>

#include <drm/drm_buddy.h>

#include "i915_ttm_buddy_manager.h"

#include "i915_gem.h"

struct i915_ttm_buddy_manager { … };

static struct i915_ttm_buddy_manager *
to_buddy_manager(struct ttm_resource_manager *man)
{ … }

static int i915_ttm_buddy_man_alloc(struct ttm_resource_manager *man,
				    struct ttm_buffer_object *bo,
				    const struct ttm_place *place,
				    struct ttm_resource **res)
{ … }

static void i915_ttm_buddy_man_free(struct ttm_resource_manager *man,
				    struct ttm_resource *res)
{ … }

static bool i915_ttm_buddy_man_intersects(struct ttm_resource_manager *man,
					  struct ttm_resource *res,
					  const struct ttm_place *place,
					  size_t size)
{ … }

static bool i915_ttm_buddy_man_compatible(struct ttm_resource_manager *man,
					  struct ttm_resource *res,
					  const struct ttm_place *place,
					  size_t size)
{ … }

static void i915_ttm_buddy_man_debug(struct ttm_resource_manager *man,
				     struct drm_printer *printer)
{ … }

static const struct ttm_resource_manager_func i915_ttm_buddy_manager_func = …;

/**
 * i915_ttm_buddy_man_init - Setup buddy allocator based ttm manager
 * @bdev: The ttm device
 * @type: Memory type we want to manage
 * @use_tt: Set use_tt for the manager
 * @size: The size in bytes to manage
 * @visible_size: The CPU visible size in bytes to manage
 * @default_page_size: The default minimum page size in bytes for allocations,
 * this must be at least as large as @chunk_size, and can be overridden by
 * setting the BO page_alignment, to be larger or smaller as needed.
 * @chunk_size: The minimum page size in bytes for our allocations i.e
 * order-zero
 *
 * Note that the starting address is assumed to be zero here, since this
 * simplifies keeping the property where allocated blocks having natural
 * power-of-two alignment. So long as the real starting address is some large
 * power-of-two, or naturally start from zero, then this should be fine.  Also
 * the &i915_ttm_buddy_man_reserve interface can be used to preserve alignment
 * if say there is some unusable range from the start of the region. We can
 * revisit this in the future and make the interface accept an actual starting
 * offset and let it take care of the rest.
 *
 * Note that if the @size is not aligned to the @chunk_size then we perform the
 * required rounding to get the usable size. The final size in pages can be
 * taken from &ttm_resource_manager.size.
 *
 * Return: 0 on success, negative error code on failure.
 */
int i915_ttm_buddy_man_init(struct ttm_device *bdev,
			    unsigned int type, bool use_tt,
			    u64 size, u64 visible_size, u64 default_page_size,
			    u64 chunk_size)
{ … }

/**
 * i915_ttm_buddy_man_fini - Destroy the buddy allocator ttm manager
 * @bdev: The ttm device
 * @type: Memory type we want to manage
 *
 * Note that if we reserved anything with &i915_ttm_buddy_man_reserve, this will
 * also be freed for us here.
 *
 * Return: 0 on success, negative error code on failure.
 */
int i915_ttm_buddy_man_fini(struct ttm_device *bdev, unsigned int type)
{ … }

/**
 * i915_ttm_buddy_man_reserve - Reserve address range
 * @man: The buddy allocator ttm manager
 * @start: The offset in bytes, where the region start is assumed to be zero
 * @size: The size in bytes
 *
 * Note that the starting address for the region is always assumed to be zero.
 *
 * Return: 0 on success, negative error code on failure.
 */
int i915_ttm_buddy_man_reserve(struct ttm_resource_manager *man,
			       u64 start, u64 size)
{ … }

/**
 * i915_ttm_buddy_man_visible_size - Return the size of the CPU visible portion
 * in pages.
 * @man: The buddy allocator ttm manager
 */
u64 i915_ttm_buddy_man_visible_size(struct ttm_resource_manager *man)
{ … }

/**
 * i915_ttm_buddy_man_avail - Query the avail tracking for the manager.
 *
 * @man: The buddy allocator ttm manager
 * @avail: The total available memory in pages for the entire manager.
 * @visible_avail: The total available memory in pages for the CPU visible
 * portion. Note that this will always give the same value as @avail on
 * configurations that don't have a small BAR.
 */
void i915_ttm_buddy_man_avail(struct ttm_resource_manager *man,
			      u64 *avail, u64 *visible_avail)
{ … }

#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
void i915_ttm_buddy_man_force_visible_size(struct ttm_resource_manager *man,
					   u64 size)
{ … }
#endif
linux/drivers/gpu/drm/i915/i915_ttm_buddy_manager.c
