[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/dma-contiguous.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);

		if (dev_get_cma_area(NULL))
			page = dma_alloc_from_contiguous(NULL, 1 << order,
							 order, false);
		else
			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
	if (!dma_release_from_contiguous(NULL, page, 1 << order))
		__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 *dev_to_pool(struct device *dev)
{
	u64 phys_mask;
	gfp_t gfp;

	gfp = dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask,
					  &phys_mask);
	if (IS_ENABLED(CONFIG_ZONE_DMA) && gfp == GFP_DMA)
		return atomic_pool_dma;
	if (IS_ENABLED(CONFIG_ZONE_DMA32) && gfp == GFP_DMA32)
		return atomic_pool_dma32;
	return atomic_pool_kernel;
}

void *dma_alloc_from_pool(struct device *dev, size_t size,
			  struct page **ret_page, gfp_t flags)
{
	struct gen_pool *pool = dev_to_pool(dev);
	unsigned long val;
	void *ptr = NULL;

	if (!pool) {
		WARN(1, "%pGg atomic pool not initialised!\n", &flags);
		return NULL;
	}

	val = gen_pool_alloc(pool, size);
	if (likely(val)) {
		phys_addr_t phys = gen_pool_virt_to_phys(pool, val);

		*ret_page = pfn_to_page(__phys_to_pfn(phys));
		ptr = (void *)val;
		memset(ptr, 0, size);
	} else {
		WARN_ONCE(1, "DMA coherent pool depleted, increase size "
			     "(recommended min coherent_pool=%zuK)\n",
			  gen_pool_size(pool) >> 9);
	}
	if (gen_pool_avail(pool) < atomic_pool_size)
		schedule_work(&atomic_pool_work);

	return ptr;
}

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

	if (!pool || !gen_pool_has_addr(pool, (unsigned long)start, size))
		return false;
	gen_pool_free(pool, (unsigned long)start, size);
	return true;
}
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>
	8	#include <linux/dma-noncoherent.h>
	9	#include <linux/dma-contiguous.h>
	10	#include <linux/init.h>
	11	#include <linux/genalloc.h>
76a19940	12	#include <linux/set_memory.h>
e860c299	13	#include <linux/slab.h>
54adadf9	14	#include <linux/workqueue.h>
e860c299	15
c84dc6e6	16	static struct gen_pool *atomic_pool_dma __ro_after_init;
2edc5bb3	17	static unsigned long pool_size_dma;
c84dc6e6	18	static struct gen_pool *atomic_pool_dma32 __ro_after_init;
2edc5bb3	19	static unsigned long pool_size_dma32;
c84dc6e6	20	static struct gen_pool *atomic_pool_kernel __ro_after_init;
2edc5bb3	21	static unsigned long pool_size_kernel;
e860c299	22
1d659236 DR	23	/* Size can be defined by the coherent_pool command line */
1d659236 DR	24	static size_t atomic_pool_size;
54adadf9 DR	25
	26	/* Dynamic background expansion when the atomic pool is near capacity */
	27	static struct work_struct atomic_pool_work;
e860c299 DR	28
	29	static int __init early_coherent_pool(char *p)
	30	{
	31	atomic_pool_size = memparse(p, &p);
	32	return 0;
	33	}
	34	early_param("coherent_pool", early_coherent_pool);
	35
2edc5bb3 DR	36	static void __init dma_atomic_pool_debugfs_init(void)
	37	{
	38	struct dentry *root;
	39
	40	root = debugfs_create_dir("dma_pools", NULL);
	41	if (IS_ERR_OR_NULL(root))
	42	return;
	43
	44	debugfs_create_ulong("pool_size_dma", 0400, root, &pool_size_dma);
	45	debugfs_create_ulong("pool_size_dma32", 0400, root, &pool_size_dma32);
	46	debugfs_create_ulong("pool_size_kernel", 0400, root, &pool_size_kernel);
	47	}
	48
	49	static void dma_atomic_pool_size_add(gfp_t gfp, size_t size)
	50	{
	51	if (gfp & __GFP_DMA)
	52	pool_size_dma += size;
	53	else if (gfp & __GFP_DMA32)
	54	pool_size_dma32 += size;
	55	else
	56	pool_size_kernel += size;
	57	}
	58
54adadf9 DR	59	static int atomic_pool_expand(struct gen_pool *pool, size_t pool_size,
54adadf9 DR	60	gfp_t gfp)
e860c299	61	{
54adadf9	62	unsigned int order;
e860c299 DR	63	struct page *page;
e860c299 DR	64	void *addr;
54adadf9 DR	65	int ret = -ENOMEM;
	66
	67	/* Cannot allocate larger than MAX_ORDER-1 */
	68	order = min(get_order(pool_size), MAX_ORDER-1);
	69
	70	do {
	71	pool_size = 1 << (PAGE_SHIFT + order);
e860c299	72
54adadf9 DR	73	if (dev_get_cma_area(NULL))
	74	page = dma_alloc_from_contiguous(NULL, 1 << order,
	75	order, false);
	76	else
	77	page = alloc_pages(gfp, order);
	78	} while (!page && order-- > 0);
e860c299 DR	79	if (!page)
	80	goto out;
	81
c84dc6e6	82	arch_dma_prep_coherent(page, pool_size);
e860c299	83
76a19940	84	#ifdef CONFIG_DMA_DIRECT_REMAP
c84dc6e6	85	addr = dma_common_contiguous_remap(page, pool_size,
e860c299 DR	86	pgprot_dmacoherent(PAGE_KERNEL),
	87	__builtin_return_address(0));
	88	if (!addr)
54adadf9	89	goto free_page;
76a19940 DR	90	#else
	91	addr = page_to_virt(page);
	92	#endif
	93	/*
	94	* Memory in the atomic DMA pools must be unencrypted, the pools do not
	95	* shrink so no re-encryption occurs in dma_direct_free_pages().
	96	*/
	97	ret = set_memory_decrypted((unsigned long)page_to_virt(page),
	98	1 << order);
	99	if (ret)
	100	goto remove_mapping;
54adadf9 DR	101	ret = gen_pool_add_virt(pool, (unsigned long)addr, page_to_phys(page),
54adadf9 DR	102	pool_size, NUMA_NO_NODE);
e860c299	103	if (ret)
76a19940	104	goto encrypt_mapping;
e860c299	105
2edc5bb3	106	dma_atomic_pool_size_add(gfp, pool_size);
e860c299 DR	107	return 0;
e860c299 DR	108
76a19940 DR	109	encrypt_mapping:
	110	ret = set_memory_encrypted((unsigned long)page_to_virt(page),
	111	1 << order);
	112	if (WARN_ON_ONCE(ret)) {
	113	/* Decrypt succeeded but encrypt failed, purposely leak */
	114	goto out;
	115	}
e860c299	116	remove_mapping:
76a19940	117	#ifdef CONFIG_DMA_DIRECT_REMAP
c84dc6e6	118	dma_common_free_remap(addr, pool_size);
76a19940 DR	119	#endif
76a19940 DR	120	free_page: __maybe_unused
54adadf9	121	if (!dma_release_from_contiguous(NULL, page, 1 << order))
c84dc6e6	122	__free_pages(page, order);
e860c299	123	out:
54adadf9 DR	124	return ret;
	125	}
	126
	127	static void atomic_pool_resize(struct gen_pool *pool, gfp_t gfp)
	128	{
	129	if (pool && gen_pool_avail(pool) < atomic_pool_size)
	130	atomic_pool_expand(pool, gen_pool_size(pool), gfp);
	131	}
	132
	133	static void atomic_pool_work_fn(struct work_struct *work)
	134	{
	135	if (IS_ENABLED(CONFIG_ZONE_DMA))
	136	atomic_pool_resize(atomic_pool_dma,
	137	GFP_KERNEL \| GFP_DMA);
	138	if (IS_ENABLED(CONFIG_ZONE_DMA32))
	139	atomic_pool_resize(atomic_pool_dma32,
	140	GFP_KERNEL \| GFP_DMA32);
	141	atomic_pool_resize(atomic_pool_kernel, GFP_KERNEL);
	142	}
	143
	144	static __init struct gen_pool *__dma_atomic_pool_init(size_t pool_size,
	145	gfp_t gfp)
	146	{
	147	struct gen_pool *pool;
	148	int ret;
	149
	150	pool = gen_pool_create(PAGE_SHIFT, NUMA_NO_NODE);
	151	if (!pool)
	152	return NULL;
	153
	154	gen_pool_set_algo(pool, gen_pool_first_fit_order_align, NULL);
	155
	156	ret = atomic_pool_expand(pool, pool_size, gfp);
	157	if (ret) {
	158	gen_pool_destroy(pool);
	159	pr_err("DMA: failed to allocate %zu KiB %pGg pool for atomic allocation\n",
	160	pool_size >> 10, &gfp);
	161	return NULL;
	162	}
	163
	164	pr_info("DMA: preallocated %zu KiB %pGg pool for atomic allocations\n",
	165	gen_pool_size(pool) >> 10, &gfp);
	166	return pool;
e860c299	167	}
c84dc6e6 DR	168
	169	static int __init dma_atomic_pool_init(void)
	170	{
	171	int ret = 0;
c84dc6e6	172
1d659236 DR	173	/*
	174	* If coherent_pool was not used on the command line, default the pool
	175	* sizes to 128KB per 1GB of memory, min 128KB, max MAX_ORDER-1.
	176	*/
	177	if (!atomic_pool_size) {
3ee06a6d GU	178	unsigned long pages = totalram_pages() / (SZ_1G / SZ_128K);
	179	pages = min_t(unsigned long, pages, MAX_ORDER_NR_PAGES);
	180	atomic_pool_size = max_t(size_t, pages << PAGE_SHIFT, SZ_128K);
1d659236	181	}
54adadf9 DR	182	INIT_WORK(&atomic_pool_work, atomic_pool_work_fn);
	183
	184	atomic_pool_kernel = __dma_atomic_pool_init(atomic_pool_size,
	185	GFP_KERNEL);
	186	if (!atomic_pool_kernel)
	187	ret = -ENOMEM;
c84dc6e6	188	if (IS_ENABLED(CONFIG_ZONE_DMA)) {
54adadf9 DR	189	atomic_pool_dma = __dma_atomic_pool_init(atomic_pool_size,
	190	GFP_KERNEL \| GFP_DMA);
	191	if (!atomic_pool_dma)
	192	ret = -ENOMEM;
c84dc6e6 DR	193	}
c84dc6e6 DR	194	if (IS_ENABLED(CONFIG_ZONE_DMA32)) {
54adadf9 DR	195	atomic_pool_dma32 = __dma_atomic_pool_init(atomic_pool_size,
	196	GFP_KERNEL \| GFP_DMA32);
	197	if (!atomic_pool_dma32)
	198	ret = -ENOMEM;
c84dc6e6	199	}
2edc5bb3 DR	200
2edc5bb3 DR	201	dma_atomic_pool_debugfs_init();
c84dc6e6 DR	202	return ret;
c84dc6e6 DR	203	}
e860c299 DR	204	postcore_initcall(dma_atomic_pool_init);
e860c299 DR	205
c84dc6e6	206	static inline struct gen_pool dev_to_pool(struct device dev)
e860c299	207	{
c84dc6e6 DR	208	u64 phys_mask;
	209	gfp_t gfp;
	210
	211	gfp = dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask,
	212	&phys_mask);
	213	if (IS_ENABLED(CONFIG_ZONE_DMA) && gfp == GFP_DMA)
	214	return atomic_pool_dma;
	215	if (IS_ENABLED(CONFIG_ZONE_DMA32) && gfp == GFP_DMA32)
	216	return atomic_pool_dma32;
	217	return atomic_pool_kernel;
	218	}
e860c299	219
c84dc6e6 DR	220	void dma_alloc_from_pool(struct device dev, size_t size,
c84dc6e6 DR	221	struct page **ret_page, gfp_t flags)
e860c299	222	{
c84dc6e6	223	struct gen_pool *pool = dev_to_pool(dev);
e860c299 DR	224	unsigned long val;
	225	void *ptr = NULL;
	226
c84dc6e6 DR	227	if (!pool) {
c84dc6e6 DR	228	WARN(1, "%pGg atomic pool not initialised!\n", &flags);
e860c299 DR	229	return NULL;
	230	}
	231
c84dc6e6	232	val = gen_pool_alloc(pool, size);
71cdec4f	233	if (likely(val)) {
c84dc6e6	234	phys_addr_t phys = gen_pool_virt_to_phys(pool, val);
e860c299 DR	235
	236	*ret_page = pfn_to_page(__phys_to_pfn(phys));
	237	ptr = (void *)val;
	238	memset(ptr, 0, size);
71cdec4f DR	239	} else {
	240	WARN_ONCE(1, "DMA coherent pool depleted, increase size "
	241	"(recommended min coherent_pool=%zuK)\n",
	242	gen_pool_size(pool) >> 9);
e860c299	243	}
54adadf9 DR	244	if (gen_pool_avail(pool) < atomic_pool_size)
54adadf9 DR	245	schedule_work(&atomic_pool_work);
e860c299 DR	246
	247	return ptr;
	248	}
	249
c84dc6e6	250	bool dma_free_from_pool(struct device dev, void start, size_t size)
e860c299	251	{
c84dc6e6 DR	252	struct gen_pool *pool = dev_to_pool(dev);
c84dc6e6 DR	253
23e469be	254	if (!pool \|\| !gen_pool_has_addr(pool, (unsigned long)start, size))
e860c299	255	return false;
c84dc6e6	256	gen_pool_free(pool, (unsigned long)start, size);
e860c299 DR	257	return true;
e860c299 DR	258	}