[linux-block.git] / kernel / dma / pool.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2012 ARM Ltd.
 * Copyright (C) 2020 Google LLC
 */
#include <linux/debugfs.h>
#include <linux/dma-direct.h>
#include <linux/dma-noncoherent.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)
{
	atomic_pool_size = memparse(p, &p);
	return 0;
}
early_param("coherent_pool", early_coherent_pool);

static void __init dma_atomic_pool_debugfs_init(void)
{
	struct dentry *root;

	root = debugfs_create_dir("dma_pools", NULL);
	if (IS_ERR_OR_NULL(root))
		return;

	debugfs_create_ulong("pool_size_dma", 0400, root, &pool_size_dma);
	debugfs_create_ulong("pool_size_dma32", 0400, root, &pool_size_dma32);
	debugfs_create_ulong("pool_size_kernel", 0400, root, &pool_size_kernel);
}

static void dma_atomic_pool_size_add(gfp_t gfp, size_t size)
{
	if (gfp & __GFP_DMA)
		pool_size_dma += size;
	else if (gfp & __GFP_DMA32)
		pool_size_dma32 += size;
	else
		pool_size_kernel += size;
}

static int atomic_pool_expand(struct gen_pool *pool, size_t pool_size,
			      gfp_t gfp)
{
	unsigned int order;
	struct page *page;
	void *addr;
	int ret = -ENOMEM;

	/* Cannot allocate larger than MAX_ORDER-1 */
	order = min(get_order(pool_size), MAX_ORDER-1);

	do {
		pool_size = 1 << (PAGE_SHIFT + order);
		page = alloc_pages(gfp, order);
	} while (!page && order-- > 0);
	if (!page)
		goto out;

	arch_dma_prep_coherent(page, pool_size);

#ifdef CONFIG_DMA_DIRECT_REMAP
	addr = dma_common_contiguous_remap(page, pool_size,
					   pgprot_dmacoherent(PAGE_KERNEL),
					   __builtin_return_address(0));
	if (!addr)
		goto free_page;
#else
	addr = page_to_virt(page);
#endif
	/*
	 * Memory in the atomic DMA pools must be unencrypted, the pools do not
	 * shrink so no re-encryption occurs in dma_direct_free_pages().
	 */
	ret = set_memory_decrypted((unsigned long)page_to_virt(page),
				   1 << order);
	if (ret)
		goto remove_mapping;
	ret = gen_pool_add_virt(pool, (unsigned long)addr, page_to_phys(page),
				pool_size, NUMA_NO_NODE);
	if (ret)
		goto encrypt_mapping;

	dma_atomic_pool_size_add(gfp, pool_size);
	return 0;

encrypt_mapping:
	ret = set_memory_encrypted((unsigned long)page_to_virt(page),
				   1 << order);
	if (WARN_ON_ONCE(ret)) {
		/* Decrypt succeeded but encrypt failed, purposely leak */
		goto out;
	}
remove_mapping:
#ifdef CONFIG_DMA_DIRECT_REMAP
	dma_common_free_remap(addr, pool_size);
#endif
free_page: __maybe_unused
	__free_pages(page, order);
out:
	return ret;
}

static void atomic_pool_resize(struct gen_pool *pool, gfp_t gfp)
{
	if (pool && gen_pool_avail(pool) < atomic_pool_size)
		atomic_pool_expand(pool, gen_pool_size(pool), gfp);
}

static void atomic_pool_work_fn(struct work_struct *work)
{
	if (IS_ENABLED(CONFIG_ZONE_DMA))
		atomic_pool_resize(atomic_pool_dma,
				   GFP_KERNEL | GFP_DMA);
	if (IS_ENABLED(CONFIG_ZONE_DMA32))
		atomic_pool_resize(atomic_pool_dma32,
				   GFP_KERNEL | GFP_DMA32);
	atomic_pool_resize(atomic_pool_kernel, GFP_KERNEL);
}

static __init struct gen_pool *__dma_atomic_pool_init(size_t pool_size,
						      gfp_t gfp)
{
	struct gen_pool *pool;
	int ret;

	pool = gen_pool_create(PAGE_SHIFT, NUMA_NO_NODE);
	if (!pool)
		return NULL;

	gen_pool_set_algo(pool, gen_pool_first_fit_order_align, NULL);

	ret = atomic_pool_expand(pool, pool_size, gfp);
	if (ret) {
		gen_pool_destroy(pool);
		pr_err("DMA: failed to allocate %zu KiB %pGg pool for atomic allocation\n",
		       pool_size >> 10, &gfp);
		return NULL;
	}

	pr_info("DMA: preallocated %zu KiB %pGg pool for atomic allocations\n",
		gen_pool_size(pool) >> 10, &gfp);
	return pool;
}

static int __init dma_atomic_pool_init(void)
{
	int ret = 0;

	/*
	 * If coherent_pool was not used on the command line, default the pool
	 * sizes to 128KB per 1GB of memory, min 128KB, max MAX_ORDER-1.
	 */
	if (!atomic_pool_size) {
		unsigned long pages = totalram_pages() / (SZ_1G / SZ_128K);
		pages = min_t(unsigned long, pages, MAX_ORDER_NR_PAGES);
		atomic_pool_size = max_t(size_t, pages << PAGE_SHIFT, SZ_128K);
	}
	INIT_WORK(&atomic_pool_work, atomic_pool_work_fn);

	atomic_pool_kernel = __dma_atomic_pool_init(atomic_pool_size,
						    GFP_KERNEL);
	if (!atomic_pool_kernel)
		ret = -ENOMEM;
	if (IS_ENABLED(CONFIG_ZONE_DMA)) {
		atomic_pool_dma = __dma_atomic_pool_init(atomic_pool_size,
						GFP_KERNEL | GFP_DMA);
		if (!atomic_pool_dma)
			ret = -ENOMEM;
	}
	if (IS_ENABLED(CONFIG_ZONE_DMA32)) {
		atomic_pool_dma32 = __dma_atomic_pool_init(atomic_pool_size,
						GFP_KERNEL | GFP_DMA32);
		if (!atomic_pool_dma32)
			ret = -ENOMEM;
	}

	dma_atomic_pool_debugfs_init();
	return ret;
}
postcore_initcall(dma_atomic_pool_init);

static inline struct gen_pool *dma_guess_pool(struct gen_pool *prev, gfp_t gfp)
{
	if (prev == NULL) {
		if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32))
			return atomic_pool_dma32;
		if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp & GFP_DMA))
			return atomic_pool_dma;
		return atomic_pool_kernel;
	}
	if (prev == atomic_pool_kernel)
		return atomic_pool_dma32 ? atomic_pool_dma32 : atomic_pool_dma;
	if (prev == atomic_pool_dma32)
		return atomic_pool_dma;
	return NULL;
}

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))
{
	unsigned long addr;
	phys_addr_t phys;

	addr = gen_pool_alloc(pool, size);
	if (!addr)
		return NULL;

	phys = gen_pool_virt_to_phys(pool, addr);
	if (phys_addr_ok && !phys_addr_ok(dev, phys, size)) {
		gen_pool_free(pool, addr, size);
		return NULL;
	}

	if (gen_pool_avail(pool) < atomic_pool_size)
		schedule_work(&atomic_pool_work);

	*cpu_addr = (void *)addr;
	memset(*cpu_addr, 0, size);
	return pfn_to_page(__phys_to_pfn(phys));
}

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))
{
	struct gen_pool *pool = NULL;
	struct page *page;

	while ((pool = dma_guess_pool(pool, gfp))) {
		page = __dma_alloc_from_pool(dev, size, pool, cpu_addr,
					     phys_addr_ok);
		if (page)
			return page;
	}

	WARN(1, "Failed to get suitable pool for %s\n", dev_name(dev));
	return NULL;
}

bool dma_free_from_pool(struct device *dev, void *start, size_t size)
{
	struct gen_pool *pool = NULL;

	while ((pool = dma_guess_pool(pool, 0))) {
		if (!gen_pool_has_addr(pool, (unsigned long)start, size))
			continue;
		gen_pool_free(pool, (unsigned long)start, size);
		return true;
	}

	return false;
}
Commit	Line	Data
e860c299 DR	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* Copyright (C) 2012 ARM Ltd.
	4	* Copyright (C) 2020 Google LLC
	5	*/
2edc5bb3	6	#include <linux/debugfs.h>
e860c299 DR	7	#include <linux/dma-direct.h>
e860c299 DR	8	#include <linux/dma-noncoherent.h>
e860c299 DR	9	#include <linux/init.h>
e860c299 DR	10	#include <linux/genalloc.h>
76a19940	11	#include <linux/set_memory.h>
e860c299	12	#include <linux/slab.h>
54adadf9	13	#include <linux/workqueue.h>
e860c299	14
c84dc6e6	15	static struct gen_pool *atomic_pool_dma __ro_after_init;
2edc5bb3	16	static unsigned long pool_size_dma;
c84dc6e6	17	static struct gen_pool *atomic_pool_dma32 __ro_after_init;
2edc5bb3	18	static unsigned long pool_size_dma32;
c84dc6e6	19	static struct gen_pool *atomic_pool_kernel __ro_after_init;
2edc5bb3	20	static unsigned long pool_size_kernel;
e860c299	21
1d659236 DR	22	/* Size can be defined by the coherent_pool command line */
1d659236 DR	23	static size_t atomic_pool_size;
54adadf9 DR	24
	25	/* Dynamic background expansion when the atomic pool is near capacity */
	26	static struct work_struct atomic_pool_work;
e860c299 DR	27
	28	static int __init early_coherent_pool(char *p)
	29	{
	30	atomic_pool_size = memparse(p, &p);
	31	return 0;
	32	}
	33	early_param("coherent_pool", early_coherent_pool);
	34
2edc5bb3 DR	35	static void __init dma_atomic_pool_debugfs_init(void)
	36	{
	37	struct dentry *root;
	38
	39	root = debugfs_create_dir("dma_pools", NULL);
	40	if (IS_ERR_OR_NULL(root))
	41	return;
	42
	43	debugfs_create_ulong("pool_size_dma", 0400, root, &pool_size_dma);
	44	debugfs_create_ulong("pool_size_dma32", 0400, root, &pool_size_dma32);
	45	debugfs_create_ulong("pool_size_kernel", 0400, root, &pool_size_kernel);
	46	}
	47
	48	static void dma_atomic_pool_size_add(gfp_t gfp, size_t size)
	49	{
	50	if (gfp & __GFP_DMA)
	51	pool_size_dma += size;
	52	else if (gfp & __GFP_DMA32)
	53	pool_size_dma32 += size;
	54	else
	55	pool_size_kernel += size;
	56	}
	57
54adadf9 DR	58	static int atomic_pool_expand(struct gen_pool *pool, size_t pool_size,
54adadf9 DR	59	gfp_t gfp)
e860c299	60	{
54adadf9	61	unsigned int order;
e860c299 DR	62	struct page *page;
e860c299 DR	63	void *addr;
54adadf9 DR	64	int ret = -ENOMEM;
	65
	66	/* Cannot allocate larger than MAX_ORDER-1 */
	67	order = min(get_order(pool_size), MAX_ORDER-1);
	68
	69	do {
	70	pool_size = 1 << (PAGE_SHIFT + order);
d9765e41	71	page = alloc_pages(gfp, order);
54adadf9	72	} while (!page && order-- > 0);
e860c299 DR	73	if (!page)
	74	goto out;
	75
c84dc6e6	76	arch_dma_prep_coherent(page, pool_size);
e860c299	77
76a19940	78	#ifdef CONFIG_DMA_DIRECT_REMAP
c84dc6e6	79	addr = dma_common_contiguous_remap(page, pool_size,
e860c299 DR	80	pgprot_dmacoherent(PAGE_KERNEL),
	81	__builtin_return_address(0));
	82	if (!addr)
54adadf9	83	goto free_page;
76a19940 DR	84	#else
	85	addr = page_to_virt(page);
	86	#endif
	87	/*
	88	* Memory in the atomic DMA pools must be unencrypted, the pools do not
	89	* shrink so no re-encryption occurs in dma_direct_free_pages().
	90	*/
	91	ret = set_memory_decrypted((unsigned long)page_to_virt(page),
	92	1 << order);
	93	if (ret)
	94	goto remove_mapping;
54adadf9 DR	95	ret = gen_pool_add_virt(pool, (unsigned long)addr, page_to_phys(page),
54adadf9 DR	96	pool_size, NUMA_NO_NODE);
e860c299	97	if (ret)
76a19940	98	goto encrypt_mapping;
e860c299	99
2edc5bb3	100	dma_atomic_pool_size_add(gfp, pool_size);
e860c299 DR	101	return 0;
e860c299 DR	102
76a19940 DR	103	encrypt_mapping:
	104	ret = set_memory_encrypted((unsigned long)page_to_virt(page),
	105	1 << order);
	106	if (WARN_ON_ONCE(ret)) {
	107	/* Decrypt succeeded but encrypt failed, purposely leak */
	108	goto out;
	109	}
e860c299	110	remove_mapping:
76a19940	111	#ifdef CONFIG_DMA_DIRECT_REMAP
c84dc6e6	112	dma_common_free_remap(addr, pool_size);
76a19940 DR	113	#endif
76a19940 DR	114	free_page: __maybe_unused
d9765e41	115	__free_pages(page, order);
e860c299	116	out:
54adadf9 DR	117	return ret;
	118	}
	119
	120	static void atomic_pool_resize(struct gen_pool *pool, gfp_t gfp)
	121	{
	122	if (pool && gen_pool_avail(pool) < atomic_pool_size)
	123	atomic_pool_expand(pool, gen_pool_size(pool), gfp);
	124	}
	125
	126	static void atomic_pool_work_fn(struct work_struct *work)
	127	{
	128	if (IS_ENABLED(CONFIG_ZONE_DMA))
	129	atomic_pool_resize(atomic_pool_dma,
	130	GFP_KERNEL \| GFP_DMA);
	131	if (IS_ENABLED(CONFIG_ZONE_DMA32))
	132	atomic_pool_resize(atomic_pool_dma32,
	133	GFP_KERNEL \| GFP_DMA32);
	134	atomic_pool_resize(atomic_pool_kernel, GFP_KERNEL);
	135	}
	136
	137	static __init struct gen_pool *__dma_atomic_pool_init(size_t pool_size,
	138	gfp_t gfp)
	139	{
	140	struct gen_pool *pool;
	141	int ret;
	142
	143	pool = gen_pool_create(PAGE_SHIFT, NUMA_NO_NODE);
	144	if (!pool)
	145	return NULL;
	146
	147	gen_pool_set_algo(pool, gen_pool_first_fit_order_align, NULL);
	148
	149	ret = atomic_pool_expand(pool, pool_size, gfp);
	150	if (ret) {
	151	gen_pool_destroy(pool);
	152	pr_err("DMA: failed to allocate %zu KiB %pGg pool for atomic allocation\n",
	153	pool_size >> 10, &gfp);
	154	return NULL;
	155	}
	156
	157	pr_info("DMA: preallocated %zu KiB %pGg pool for atomic allocations\n",
	158	gen_pool_size(pool) >> 10, &gfp);
	159	return pool;
e860c299	160	}
c84dc6e6 DR	161
	162	static int __init dma_atomic_pool_init(void)
	163	{
	164	int ret = 0;
c84dc6e6	165
1d659236 DR	166	/*
	167	* If coherent_pool was not used on the command line, default the pool
	168	* sizes to 128KB per 1GB of memory, min 128KB, max MAX_ORDER-1.
	169	*/
	170	if (!atomic_pool_size) {
3ee06a6d GU	171	unsigned long pages = totalram_pages() / (SZ_1G / SZ_128K);
	172	pages = min_t(unsigned long, pages, MAX_ORDER_NR_PAGES);
	173	atomic_pool_size = max_t(size_t, pages << PAGE_SHIFT, SZ_128K);
1d659236	174	}
54adadf9 DR	175	INIT_WORK(&atomic_pool_work, atomic_pool_work_fn);
	176
	177	atomic_pool_kernel = __dma_atomic_pool_init(atomic_pool_size,
	178	GFP_KERNEL);
	179	if (!atomic_pool_kernel)
	180	ret = -ENOMEM;
c84dc6e6	181	if (IS_ENABLED(CONFIG_ZONE_DMA)) {
54adadf9 DR	182	atomic_pool_dma = __dma_atomic_pool_init(atomic_pool_size,
	183	GFP_KERNEL \| GFP_DMA);
	184	if (!atomic_pool_dma)
	185	ret = -ENOMEM;
c84dc6e6 DR	186	}
c84dc6e6 DR	187	if (IS_ENABLED(CONFIG_ZONE_DMA32)) {
54adadf9 DR	188	atomic_pool_dma32 = __dma_atomic_pool_init(atomic_pool_size,
	189	GFP_KERNEL \| GFP_DMA32);
	190	if (!atomic_pool_dma32)
	191	ret = -ENOMEM;
c84dc6e6	192	}
2edc5bb3 DR	193
2edc5bb3 DR	194	dma_atomic_pool_debugfs_init();
c84dc6e6 DR	195	return ret;
c84dc6e6 DR	196	}
e860c299 DR	197	postcore_initcall(dma_atomic_pool_init);
e860c299 DR	198
9420139f	199	static inline struct gen_pool dma_guess_pool(struct gen_pool prev, gfp_t gfp)
e860c299	200	{
9420139f CH	201	if (prev == NULL) {
	202	if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32))
	203	return atomic_pool_dma32;
	204	if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp & GFP_DMA))
	205	return atomic_pool_dma;
	206	return atomic_pool_kernel;
	207	}
	208	if (prev == atomic_pool_kernel)
	209	return atomic_pool_dma32 ? atomic_pool_dma32 : atomic_pool_dma;
	210	if (prev == atomic_pool_dma32)
c84dc6e6	211	return atomic_pool_dma;
9420139f	212	return NULL;
c84dc6e6	213	}
e860c299	214
9420139f CH	215	static struct page __dma_alloc_from_pool(struct device dev, size_t size,
	216	struct gen_pool pool, void *cpu_addr,
	217	bool (phys_addr_ok)(struct device , phys_addr_t, size_t))
48b67038	218	{
9420139f CH	219	unsigned long addr;
9420139f CH	220	phys_addr_t phys;
48b67038	221
9420139f CH	222	addr = gen_pool_alloc(pool, size);
	223	if (!addr)
	224	return NULL;
48b67038	225
9420139f CH	226	phys = gen_pool_virt_to_phys(pool, addr);
	227	if (phys_addr_ok && !phys_addr_ok(dev, phys, size)) {
	228	gen_pool_free(pool, addr, size);
	229	return NULL;
	230	}
48b67038	231
9420139f CH	232	if (gen_pool_avail(pool) < atomic_pool_size)
9420139f CH	233	schedule_work(&atomic_pool_work);
48b67038	234
9420139f CH	235	cpu_addr = (void )addr;
	236	memset(*cpu_addr, 0, size);
	237	return pfn_to_page(__phys_to_pfn(phys));
48b67038 NSJ	238	}
48b67038 NSJ	239
9420139f CH	240	struct page dma_alloc_from_pool(struct device dev, size_t size,
	241	void **cpu_addr, gfp_t gfp,
	242	bool (phys_addr_ok)(struct device , phys_addr_t, size_t))
e860c299	243	{
81e9d894	244	struct gen_pool *pool = NULL;
9420139f	245	struct page *page;
81e9d894	246
9420139f CH	247	while ((pool = dma_guess_pool(pool, gfp))) {
	248	page = __dma_alloc_from_pool(dev, size, pool, cpu_addr,
	249	phys_addr_ok);
	250	if (page)
	251	return page;
e860c299 DR	252	}
e860c299 DR	253
9420139f CH	254	WARN(1, "Failed to get suitable pool for %s\n", dev_name(dev));
9420139f CH	255	return NULL;
e860c299 DR	256	}
e860c299 DR	257
c84dc6e6	258	bool dma_free_from_pool(struct device dev, void start, size_t size)
e860c299	259	{
81e9d894	260	struct gen_pool *pool = NULL;
c84dc6e6	261
9420139f CH	262	while ((pool = dma_guess_pool(pool, 0))) {
	263	if (!gen_pool_has_addr(pool, (unsigned long)start, size))
	264	continue;
	265	gen_pool_free(pool, (unsigned long)start, size);
	266	return true;
81e9d894	267	}
9420139f CH	268
9420139f CH	269	return false;
e860c299	270	}