[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/cma.h>
#include <linux/debugfs.h>
#include <linux/dma-contiguous.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 bool cma_in_zone(gfp_t gfp)
{
	unsigned long size;
	phys_addr_t end;
	struct cma *cma;

	cma = dev_get_cma_area(NULL);
	if (!cma)
		return false;

	size = cma_get_size(cma);
	if (!size)
		return false;

	/* CMA can't cross zone boundaries, see cma_activate_area() */
	end = cma_get_base(cma) + size - 1;
	if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp & GFP_DMA))
		return end <= DMA_BIT_MASK(zone_dma_bits);
	if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32))
		return end <= DMA_BIT_MASK(32);
	return true;
}

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);
		if (cma_in_zone(gfp))
			page = dma_alloc_from_contiguous(NULL, 1 << order,
							 order, false);
		if (!page)
			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	*/
d7e673ec	6	#include <linux/cma.h>
2edc5bb3	7	#include <linux/debugfs.h>
d7e673ec	8	#include <linux/dma-contiguous.h>
e860c299 DR	9	#include <linux/dma-direct.h>
e860c299 DR	10	#include <linux/dma-noncoherent.h>
e860c299 DR	11	#include <linux/init.h>
e860c299 DR	12	#include <linux/genalloc.h>
76a19940	13	#include <linux/set_memory.h>
e860c299	14	#include <linux/slab.h>
54adadf9	15	#include <linux/workqueue.h>
e860c299	16
c84dc6e6	17	static struct gen_pool *atomic_pool_dma __ro_after_init;
2edc5bb3	18	static unsigned long pool_size_dma;
c84dc6e6	19	static struct gen_pool *atomic_pool_dma32 __ro_after_init;
2edc5bb3	20	static unsigned long pool_size_dma32;
c84dc6e6	21	static struct gen_pool *atomic_pool_kernel __ro_after_init;
2edc5bb3	22	static unsigned long pool_size_kernel;
e860c299	23
1d659236 DR	24	/* Size can be defined by the coherent_pool command line */
1d659236 DR	25	static size_t atomic_pool_size;
54adadf9 DR	26
	27	/* Dynamic background expansion when the atomic pool is near capacity */
	28	static struct work_struct atomic_pool_work;
e860c299 DR	29
	30	static int __init early_coherent_pool(char *p)
	31	{
	32	atomic_pool_size = memparse(p, &p);
	33	return 0;
	34	}
	35	early_param("coherent_pool", early_coherent_pool);
	36
2edc5bb3 DR	37	static void __init dma_atomic_pool_debugfs_init(void)
	38	{
	39	struct dentry *root;
	40
	41	root = debugfs_create_dir("dma_pools", NULL);
	42	if (IS_ERR_OR_NULL(root))
	43	return;
	44
	45	debugfs_create_ulong("pool_size_dma", 0400, root, &pool_size_dma);
	46	debugfs_create_ulong("pool_size_dma32", 0400, root, &pool_size_dma32);
	47	debugfs_create_ulong("pool_size_kernel", 0400, root, &pool_size_kernel);
	48	}
	49
	50	static void dma_atomic_pool_size_add(gfp_t gfp, size_t size)
	51	{
	52	if (gfp & __GFP_DMA)
	53	pool_size_dma += size;
	54	else if (gfp & __GFP_DMA32)
	55	pool_size_dma32 += size;
	56	else
	57	pool_size_kernel += size;
	58	}
	59
d7e673ec NSJ	60	static bool cma_in_zone(gfp_t gfp)
	61	{
	62	unsigned long size;
	63	phys_addr_t end;
	64	struct cma *cma;
	65
	66	cma = dev_get_cma_area(NULL);
	67	if (!cma)
	68	return false;
	69
	70	size = cma_get_size(cma);
	71	if (!size)
	72	return false;
	73
	74	/* CMA can't cross zone boundaries, see cma_activate_area() */
	75	end = cma_get_base(cma) + size - 1;
	76	if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp & GFP_DMA))
	77	return end <= DMA_BIT_MASK(zone_dma_bits);
	78	if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32))
	79	return end <= DMA_BIT_MASK(32);
	80	return true;
	81	}
	82
54adadf9 DR	83	static int atomic_pool_expand(struct gen_pool *pool, size_t pool_size,
54adadf9 DR	84	gfp_t gfp)
e860c299	85	{
54adadf9	86	unsigned int order;
e860c299 DR	87	struct page *page;
e860c299 DR	88	void *addr;
54adadf9 DR	89	int ret = -ENOMEM;
	90
	91	/* Cannot allocate larger than MAX_ORDER-1 */
	92	order = min(get_order(pool_size), MAX_ORDER-1);
	93
	94	do {
	95	pool_size = 1 << (PAGE_SHIFT + order);
d7e673ec NSJ	96	if (cma_in_zone(gfp))
	97	page = dma_alloc_from_contiguous(NULL, 1 << order,
	98	order, false);
	99	if (!page)
	100	page = alloc_pages(gfp, order);
54adadf9	101	} while (!page && order-- > 0);
e860c299 DR	102	if (!page)
	103	goto out;
	104
c84dc6e6	105	arch_dma_prep_coherent(page, pool_size);
e860c299	106
76a19940	107	#ifdef CONFIG_DMA_DIRECT_REMAP
c84dc6e6	108	addr = dma_common_contiguous_remap(page, pool_size,
e860c299 DR	109	pgprot_dmacoherent(PAGE_KERNEL),
	110	__builtin_return_address(0));
	111	if (!addr)
54adadf9	112	goto free_page;
76a19940 DR	113	#else
	114	addr = page_to_virt(page);
	115	#endif
	116	/*
	117	* Memory in the atomic DMA pools must be unencrypted, the pools do not
	118	* shrink so no re-encryption occurs in dma_direct_free_pages().
	119	*/
	120	ret = set_memory_decrypted((unsigned long)page_to_virt(page),
	121	1 << order);
	122	if (ret)
	123	goto remove_mapping;
54adadf9 DR	124	ret = gen_pool_add_virt(pool, (unsigned long)addr, page_to_phys(page),
54adadf9 DR	125	pool_size, NUMA_NO_NODE);
e860c299	126	if (ret)
76a19940	127	goto encrypt_mapping;
e860c299	128
2edc5bb3	129	dma_atomic_pool_size_add(gfp, pool_size);
e860c299 DR	130	return 0;
e860c299 DR	131
76a19940 DR	132	encrypt_mapping:
	133	ret = set_memory_encrypted((unsigned long)page_to_virt(page),
	134	1 << order);
	135	if (WARN_ON_ONCE(ret)) {
	136	/* Decrypt succeeded but encrypt failed, purposely leak */
	137	goto out;
	138	}
e860c299	139	remove_mapping:
76a19940	140	#ifdef CONFIG_DMA_DIRECT_REMAP
c84dc6e6	141	dma_common_free_remap(addr, pool_size);
76a19940 DR	142	#endif
76a19940 DR	143	free_page: __maybe_unused
d9765e41	144	__free_pages(page, order);
e860c299	145	out:
54adadf9 DR	146	return ret;
	147	}
	148
	149	static void atomic_pool_resize(struct gen_pool *pool, gfp_t gfp)
	150	{
	151	if (pool && gen_pool_avail(pool) < atomic_pool_size)
	152	atomic_pool_expand(pool, gen_pool_size(pool), gfp);
	153	}
	154
	155	static void atomic_pool_work_fn(struct work_struct *work)
	156	{
	157	if (IS_ENABLED(CONFIG_ZONE_DMA))
	158	atomic_pool_resize(atomic_pool_dma,
	159	GFP_KERNEL \| GFP_DMA);
	160	if (IS_ENABLED(CONFIG_ZONE_DMA32))
	161	atomic_pool_resize(atomic_pool_dma32,
	162	GFP_KERNEL \| GFP_DMA32);
	163	atomic_pool_resize(atomic_pool_kernel, GFP_KERNEL);
	164	}
	165
	166	static __init struct gen_pool *__dma_atomic_pool_init(size_t pool_size,
	167	gfp_t gfp)
	168	{
	169	struct gen_pool *pool;
	170	int ret;
	171
	172	pool = gen_pool_create(PAGE_SHIFT, NUMA_NO_NODE);
	173	if (!pool)
	174	return NULL;
	175
	176	gen_pool_set_algo(pool, gen_pool_first_fit_order_align, NULL);
	177
	178	ret = atomic_pool_expand(pool, pool_size, gfp);
	179	if (ret) {
	180	gen_pool_destroy(pool);
	181	pr_err("DMA: failed to allocate %zu KiB %pGg pool for atomic allocation\n",
	182	pool_size >> 10, &gfp);
	183	return NULL;
	184	}
	185
	186	pr_info("DMA: preallocated %zu KiB %pGg pool for atomic allocations\n",
	187	gen_pool_size(pool) >> 10, &gfp);
	188	return pool;
e860c299	189	}
c84dc6e6 DR	190
	191	static int __init dma_atomic_pool_init(void)
	192	{
	193	int ret = 0;
c84dc6e6	194
1d659236 DR	195	/*
	196	* If coherent_pool was not used on the command line, default the pool
	197	* sizes to 128KB per 1GB of memory, min 128KB, max MAX_ORDER-1.
	198	*/
	199	if (!atomic_pool_size) {
3ee06a6d GU	200	unsigned long pages = totalram_pages() / (SZ_1G / SZ_128K);
	201	pages = min_t(unsigned long, pages, MAX_ORDER_NR_PAGES);
	202	atomic_pool_size = max_t(size_t, pages << PAGE_SHIFT, SZ_128K);
1d659236	203	}
54adadf9 DR	204	INIT_WORK(&atomic_pool_work, atomic_pool_work_fn);
	205
	206	atomic_pool_kernel = __dma_atomic_pool_init(atomic_pool_size,
	207	GFP_KERNEL);
	208	if (!atomic_pool_kernel)
	209	ret = -ENOMEM;
c84dc6e6	210	if (IS_ENABLED(CONFIG_ZONE_DMA)) {
54adadf9 DR	211	atomic_pool_dma = __dma_atomic_pool_init(atomic_pool_size,
	212	GFP_KERNEL \| GFP_DMA);
	213	if (!atomic_pool_dma)
	214	ret = -ENOMEM;
c84dc6e6 DR	215	}
c84dc6e6 DR	216	if (IS_ENABLED(CONFIG_ZONE_DMA32)) {
54adadf9 DR	217	atomic_pool_dma32 = __dma_atomic_pool_init(atomic_pool_size,
	218	GFP_KERNEL \| GFP_DMA32);
	219	if (!atomic_pool_dma32)
	220	ret = -ENOMEM;
c84dc6e6	221	}
2edc5bb3 DR	222
2edc5bb3 DR	223	dma_atomic_pool_debugfs_init();
c84dc6e6 DR	224	return ret;
c84dc6e6 DR	225	}
e860c299 DR	226	postcore_initcall(dma_atomic_pool_init);
e860c299 DR	227
9420139f	228	static inline struct gen_pool dma_guess_pool(struct gen_pool prev, gfp_t gfp)
e860c299	229	{
9420139f CH	230	if (prev == NULL) {
	231	if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32))
	232	return atomic_pool_dma32;
	233	if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp & GFP_DMA))
	234	return atomic_pool_dma;
	235	return atomic_pool_kernel;
	236	}
	237	if (prev == atomic_pool_kernel)
	238	return atomic_pool_dma32 ? atomic_pool_dma32 : atomic_pool_dma;
	239	if (prev == atomic_pool_dma32)
c84dc6e6	240	return atomic_pool_dma;
9420139f	241	return NULL;
c84dc6e6	242	}
e860c299	243
9420139f CH	244	static struct page __dma_alloc_from_pool(struct device dev, size_t size,
	245	struct gen_pool pool, void *cpu_addr,
	246	bool (phys_addr_ok)(struct device , phys_addr_t, size_t))
48b67038	247	{
9420139f CH	248	unsigned long addr;
9420139f CH	249	phys_addr_t phys;
48b67038	250
9420139f CH	251	addr = gen_pool_alloc(pool, size);
	252	if (!addr)
	253	return NULL;
48b67038	254
9420139f CH	255	phys = gen_pool_virt_to_phys(pool, addr);
	256	if (phys_addr_ok && !phys_addr_ok(dev, phys, size)) {
	257	gen_pool_free(pool, addr, size);
	258	return NULL;
	259	}
48b67038	260
9420139f CH	261	if (gen_pool_avail(pool) < atomic_pool_size)
9420139f CH	262	schedule_work(&atomic_pool_work);
48b67038	263
9420139f CH	264	cpu_addr = (void )addr;
	265	memset(*cpu_addr, 0, size);
	266	return pfn_to_page(__phys_to_pfn(phys));
48b67038 NSJ	267	}
48b67038 NSJ	268
9420139f CH	269	struct page dma_alloc_from_pool(struct device dev, size_t size,
	270	void **cpu_addr, gfp_t gfp,
	271	bool (phys_addr_ok)(struct device , phys_addr_t, size_t))
e860c299	272	{
81e9d894	273	struct gen_pool *pool = NULL;
9420139f	274	struct page *page;
81e9d894	275
9420139f CH	276	while ((pool = dma_guess_pool(pool, gfp))) {
	277	page = __dma_alloc_from_pool(dev, size, pool, cpu_addr,
	278	phys_addr_ok);
	279	if (page)
	280	return page;
e860c299 DR	281	}
e860c299 DR	282
9420139f CH	283	WARN(1, "Failed to get suitable pool for %s\n", dev_name(dev));
9420139f CH	284	return NULL;
e860c299 DR	285	}
e860c299 DR	286
c84dc6e6	287	bool dma_free_from_pool(struct device dev, void start, size_t size)
e860c299	288	{
81e9d894	289	struct gen_pool *pool = NULL;
c84dc6e6	290
9420139f CH	291	while ((pool = dma_guess_pool(pool, 0))) {
	292	if (!gen_pool_has_addr(pool, (unsigned long)start, size))
	293	continue;
	294	gen_pool_free(pool, (unsigned long)start, size);
	295	return true;
81e9d894	296	}
9420139f CH	297
9420139f CH	298	return false;
e860c299	299	}