linux/kernel/dma/pool.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2012 ARM Ltd.
 * Copyright (C) 2020 Google LLC
 */
#include <linux/cma.h>
#include <linux/debugfs.h>
#include <linux/dma-map-ops.h>
#include <linux/dma-direct.h>
#include <linux/init.h>
#include <linux/genalloc.h>
#include <linux/set_memory.h>
#include <linux/slab.h>
#include <linux/workqueue.h>

static struct gen_pool *atomic_pool_dma __ro_after_init;
static unsigned long pool_size_dma;
static struct gen_pool *atomic_pool_dma32 __ro_after_init;
static unsigned long pool_size_dma32;
static struct gen_pool *atomic_pool_kernel __ro_after_init;
static unsigned long pool_size_kernel;

/* Size can be defined by the coherent_pool command line */
static size_t atomic_pool_size;

/* Dynamic background expansion when the atomic pool is near capacity */
static struct work_struct atomic_pool_work;

static int __init early_coherent_pool(char *p)
{ … }
early_param(…);

static void __init dma_atomic_pool_debugfs_init(void)
{ … }

static void dma_atomic_pool_size_add(gfp_t gfp, size_t size)
{ … }

static bool cma_in_zone(gfp_t gfp)
{ … }

static int atomic_pool_expand(struct gen_pool *pool, size_t pool_size,
			      gfp_t gfp)
{ … }

static void atomic_pool_resize(struct gen_pool *pool, gfp_t gfp)
{ … }

static void atomic_pool_work_fn(struct work_struct *work)
{ … }

static __init struct gen_pool *__dma_atomic_pool_init(size_t pool_size,
						      gfp_t gfp)
{ … }

static int __init dma_atomic_pool_init(void)
{ … }
postcore_initcall(dma_atomic_pool_init);

static inline struct gen_pool *dma_guess_pool(struct gen_pool *prev, gfp_t gfp)
{ … }

static struct page *__dma_alloc_from_pool(struct device *dev, size_t size,
		struct gen_pool *pool, void **cpu_addr,
		bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t))
{ … }

struct page *dma_alloc_from_pool(struct device *dev, size_t size,
		void **cpu_addr, gfp_t gfp,
		bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t))
{ … }

bool dma_free_from_pool(struct device *dev, void *start, size_t size)
{ … }