// SPDX-License-Identifier: MIT
/*
 * Copyright © 2019 Intel Corporation
 */

#include "intel_memory_region.h"
#include "i915_drv.h"

/* XXX: Hysterical raisins. BIT(inst) needs to just be (inst) at some point. */
#define REGION_MAP(type, inst) \
	BIT((type) + INTEL_MEMORY_TYPE_SHIFT) | BIT(inst)

const u32 intel_region_map[] = {
	[INTEL_REGION_SMEM] = REGION_MAP(INTEL_MEMORY_SYSTEM, 0),
	[INTEL_REGION_LMEM] = REGION_MAP(INTEL_MEMORY_LOCAL, 0),
	[INTEL_REGION_STOLEN] = REGION_MAP(INTEL_MEMORY_STOLEN, 0),
};

static u64
intel_memory_region_free_pages(struct intel_memory_region *mem,
			       struct list_head *blocks)
{
	struct i915_buddy_block *block, *on;
	u64 size = 0;

	list_for_each_entry_safe(block, on, blocks, link) {
		size += i915_buddy_block_size(&mem->mm, block);
		i915_buddy_free(&mem->mm, block);
	}
	INIT_LIST_HEAD(blocks);

	return size;
}

void
__intel_memory_region_put_pages_buddy(struct intel_memory_region *mem,
				      struct list_head *blocks)
{
	mutex_lock(&mem->mm_lock);
	intel_memory_region_free_pages(mem, blocks);
	mutex_unlock(&mem->mm_lock);
}

void
__intel_memory_region_put_block_buddy(struct i915_buddy_block *block)
{
	struct list_head blocks;

	INIT_LIST_HEAD(&blocks);
	list_add(&block->link, &blocks);
	__intel_memory_region_put_pages_buddy(block->private, &blocks);
}

int
__intel_memory_region_get_pages_buddy(struct intel_memory_region *mem,
				      resource_size_t size,
				      unsigned int flags,
				      struct list_head *blocks)
{
	unsigned int min_order = 0;
	unsigned long n_pages;

	GEM_BUG_ON(!IS_ALIGNED(size, mem->mm.chunk_size));
	GEM_BUG_ON(!list_empty(blocks));

	if (flags & I915_ALLOC_MIN_PAGE_SIZE) {
		min_order = ilog2(mem->min_page_size) -
			    ilog2(mem->mm.chunk_size);
	}

	if (flags & I915_ALLOC_CONTIGUOUS) {
		size = roundup_pow_of_two(size);
		min_order = ilog2(size) - ilog2(mem->mm.chunk_size);
	}

	n_pages = size >> ilog2(mem->mm.chunk_size);

	mutex_lock(&mem->mm_lock);

	do {
		struct i915_buddy_block *block;
		unsigned int order;

		order = fls(n_pages) - 1;
		GEM_BUG_ON(order > mem->mm.max_order);
		GEM_BUG_ON(order < min_order);

		do {
			block = i915_buddy_alloc(&mem->mm, order);
			if (!IS_ERR(block))
				break;

			if (order-- == min_order)
				goto err_free_blocks;
		} while (1);

		n_pages -= BIT(order);

		block->private = mem;
		list_add(&block->link, blocks);

		if (!n_pages)
			break;
	} while (1);

	mutex_unlock(&mem->mm_lock);
	return 0;

err_free_blocks:
	intel_memory_region_free_pages(mem, blocks);
	mutex_unlock(&mem->mm_lock);
	return -ENXIO;
}

struct i915_buddy_block *
__intel_memory_region_get_block_buddy(struct intel_memory_region *mem,
				      resource_size_t size,
				      unsigned int flags)
{
	struct i915_buddy_block *block;
	LIST_HEAD(blocks);
	int ret;

	ret = __intel_memory_region_get_pages_buddy(mem, size, flags, &blocks);
	if (ret)
		return ERR_PTR(ret);

	block = list_first_entry(&blocks, typeof(*block), link);
	list_del_init(&block->link);
	return block;
}

int intel_memory_region_init_buddy(struct intel_memory_region *mem)
{
	return i915_buddy_init(&mem->mm, resource_size(&mem->region),
			       PAGE_SIZE);
}

void intel_memory_region_release_buddy(struct intel_memory_region *mem)
{
	i915_buddy_fini(&mem->mm);
}

struct intel_memory_region *
intel_memory_region_create(struct drm_i915_private *i915,
			   resource_size_t start,
			   resource_size_t size,
			   resource_size_t min_page_size,
			   resource_size_t io_start,
			   const struct intel_memory_region_ops *ops)
{
	struct intel_memory_region *mem;
	int err;

	mem = kzalloc(sizeof(*mem), GFP_KERNEL);
	if (!mem)
		return ERR_PTR(-ENOMEM);

	mem->i915 = i915;
	mem->region = (struct resource)DEFINE_RES_MEM(start, size);
	mem->io_start = io_start;
	mem->min_page_size = min_page_size;
	mem->ops = ops;

	mutex_init(&mem->objects.lock);
	INIT_LIST_HEAD(&mem->objects.list);
	INIT_LIST_HEAD(&mem->objects.purgeable);

	mutex_init(&mem->mm_lock);

	if (ops->init) {
		err = ops->init(mem);
		if (err)
			goto err_free;
	}

	kref_init(&mem->kref);
	return mem;

err_free:
	kfree(mem);
	return ERR_PTR(err);
}

static void __intel_memory_region_destroy(struct kref *kref)
{
	struct intel_memory_region *mem =
		container_of(kref, typeof(*mem), kref);

	if (mem->ops->release)
		mem->ops->release(mem);

	mutex_destroy(&mem->mm_lock);
	mutex_destroy(&mem->objects.lock);
	kfree(mem);
}

struct intel_memory_region *
intel_memory_region_get(struct intel_memory_region *mem)
{
	kref_get(&mem->kref);
	return mem;
}

void intel_memory_region_put(struct intel_memory_region *mem)
{
	kref_put(&mem->kref, __intel_memory_region_destroy);
}

#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
#include "selftests/intel_memory_region.c"
#include "selftests/mock_region.c"
#endif