[mirror_ubuntu-zesty-kernel.git] / mm / cma_debug.c

/*
 * CMA DebugFS Interface
 *
 * Copyright (c) 2015 Sasha Levin <sasha.levin@oracle.com>
 */


#include <linux/debugfs.h>
#include <linux/cma.h>
#include <linux/list.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/mm_types.h>

#include "cma.h"

struct cma_mem {
	struct hlist_node node;
	struct page *p;
	unsigned long n;
};

static struct dentry *cma_debugfs_root;

static int cma_debugfs_get(void *data, u64 *val)
{
	unsigned long *p = data;

	*val = *p;

	return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(cma_debugfs_fops, cma_debugfs_get, NULL, "%llu\n");

static int cma_used_get(void *data, u64 *val)
{
	struct cma *cma = data;
	unsigned long used;

	mutex_lock(&cma->lock);
	/* pages counter is smaller than sizeof(int) */
	used = bitmap_weight(cma->bitmap, (int)cma_bitmap_maxno(cma));
	mutex_unlock(&cma->lock);
	*val = (u64)used << cma->order_per_bit;

	return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(cma_used_fops, cma_used_get, NULL, "%llu\n");

static int cma_maxchunk_get(void *data, u64 *val)
{
	struct cma *cma = data;
	unsigned long maxchunk = 0;
	unsigned long start, end = 0;
	unsigned long bitmap_maxno = cma_bitmap_maxno(cma);

	mutex_lock(&cma->lock);
	for (;;) {
		start = find_next_zero_bit(cma->bitmap, bitmap_maxno, end);
		if (start >= cma->count)
			break;
		end = find_next_bit(cma->bitmap, bitmap_maxno, start);
		maxchunk = max(end - start, maxchunk);
	}
	mutex_unlock(&cma->lock);
	*val = (u64)maxchunk << cma->order_per_bit;

	return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(cma_maxchunk_fops, cma_maxchunk_get, NULL, "%llu\n");

static void cma_add_to_cma_mem_list(struct cma *cma, struct cma_mem *mem)
{
	spin_lock(&cma->mem_head_lock);
	hlist_add_head(&mem->node, &cma->mem_head);
	spin_unlock(&cma->mem_head_lock);
}

static struct cma_mem *cma_get_entry_from_list(struct cma *cma)
{
	struct cma_mem *mem = NULL;

	spin_lock(&cma->mem_head_lock);
	if (!hlist_empty(&cma->mem_head)) {
		mem = hlist_entry(cma->mem_head.first, struct cma_mem, node);
		hlist_del_init(&mem->node);
	}
	spin_unlock(&cma->mem_head_lock);

	return mem;
}

static int cma_free_mem(struct cma *cma, int count)
{
	struct cma_mem *mem = NULL;

	while (count) {
		mem = cma_get_entry_from_list(cma);
		if (mem == NULL)
			return 0;

		if (mem->n <= count) {
			cma_release(cma, mem->p, mem->n);
			count -= mem->n;
			kfree(mem);
		} else if (cma->order_per_bit == 0) {
			cma_release(cma, mem->p, count);
			mem->p += count;
			mem->n -= count;
			count = 0;
			cma_add_to_cma_mem_list(cma, mem);
		} else {
			pr_debug("cma: cannot release partial block when order_per_bit != 0\n");
			cma_add_to_cma_mem_list(cma, mem);
			break;
		}
	}

	return 0;

}

static int cma_free_write(void *data, u64 val)
{
	int pages = val;
	struct cma *cma = data;

	return cma_free_mem(cma, pages);
}
DEFINE_SIMPLE_ATTRIBUTE(cma_free_fops, NULL, cma_free_write, "%llu\n");

static int cma_alloc_mem(struct cma *cma, int count)
{
	struct cma_mem *mem;
	struct page *p;

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

	p = cma_alloc(cma, count, 0);
	if (!p) {
		kfree(mem);
		return -ENOMEM;
	}

	mem->p = p;
	mem->n = count;

	cma_add_to_cma_mem_list(cma, mem);

	return 0;
}

static int cma_alloc_write(void *data, u64 val)
{
	int pages = val;
	struct cma *cma = data;

	return cma_alloc_mem(cma, pages);
}
DEFINE_SIMPLE_ATTRIBUTE(cma_alloc_fops, NULL, cma_alloc_write, "%llu\n");

static void cma_debugfs_add_one(struct cma *cma, int idx)
{
	struct dentry *tmp;
	char name[16];
	int u32s;

	sprintf(name, "cma-%d", idx);

	tmp = debugfs_create_dir(name, cma_debugfs_root);

	debugfs_create_file("alloc", S_IWUSR, tmp, cma,
				&cma_alloc_fops);

	debugfs_create_file("free", S_IWUSR, tmp, cma,
				&cma_free_fops);

	debugfs_create_file("base_pfn", S_IRUGO, tmp,
				&cma->base_pfn, &cma_debugfs_fops);
	debugfs_create_file("count", S_IRUGO, tmp,
				&cma->count, &cma_debugfs_fops);
	debugfs_create_file("order_per_bit", S_IRUGO, tmp,
				&cma->order_per_bit, &cma_debugfs_fops);
	debugfs_create_file("used", S_IRUGO, tmp, cma, &cma_used_fops);
	debugfs_create_file("maxchunk", S_IRUGO, tmp, cma, &cma_maxchunk_fops);

	u32s = DIV_ROUND_UP(cma_bitmap_maxno(cma), BITS_PER_BYTE * sizeof(u32));
	debugfs_create_u32_array("bitmap", S_IRUGO, tmp, (u32*)cma->bitmap, u32s);
}

static int __init cma_debugfs_init(void)
{
	int i;

	cma_debugfs_root = debugfs_create_dir("cma", NULL);
	if (!cma_debugfs_root)
		return -ENOMEM;

	for (i = 0; i < cma_area_count; i++)
		cma_debugfs_add_one(&cma_areas[i], i);

	return 0;
}
late_initcall(cma_debugfs_init);
Commit	Line	Data
28b24c1f SL	1	/*
	2	* CMA DebugFS Interface
	3	*
	4	* Copyright (c) 2015 Sasha Levin <sasha.levin@oracle.com>
	5	*/
	6
	7
	8	#include <linux/debugfs.h>
	9	#include <linux/cma.h>
26b02a1f SL	10	#include <linux/list.h>
	11	#include <linux/kernel.h>
	12	#include <linux/slab.h>
8325330b	13	#include <linux/mm_types.h>
28b24c1f SL	14
	15	#include "cma.h"
	16
26b02a1f SL	17	struct cma_mem {
	18	struct hlist_node node;
	19	struct page *p;
	20	unsigned long n;
	21	};
	22
28b24c1f SL	23	static struct dentry *cma_debugfs_root;
	24
	25	static int cma_debugfs_get(void data, u64 val)
	26	{
	27	unsigned long *p = data;
	28
	29	val = p;
	30
	31	return 0;
	32	}
28b24c1f SL	33	DEFINE_SIMPLE_ATTRIBUTE(cma_debugfs_fops, cma_debugfs_get, NULL, "%llu\n");
28b24c1f SL	34
2e32b947 DS	35	static int cma_used_get(void data, u64 val)
	36	{
	37	struct cma *cma = data;
	38	unsigned long used;
	39
	40	mutex_lock(&cma->lock);
	41	/* pages counter is smaller than sizeof(int) */
d56e84b4	42	used = bitmap_weight(cma->bitmap, (int)cma_bitmap_maxno(cma));
2e32b947 DS	43	mutex_unlock(&cma->lock);
	44	*val = (u64)used << cma->order_per_bit;
	45
	46	return 0;
	47	}
2e32b947 DS	48	DEFINE_SIMPLE_ATTRIBUTE(cma_used_fops, cma_used_get, NULL, "%llu\n");
	49
	50	static int cma_maxchunk_get(void data, u64 val)
	51	{
	52	struct cma *cma = data;
	53	unsigned long maxchunk = 0;
	54	unsigned long start, end = 0;
d56e84b4	55	unsigned long bitmap_maxno = cma_bitmap_maxno(cma);
2e32b947 DS	56
	57	mutex_lock(&cma->lock);
	58	for (;;) {
d56e84b4	59	start = find_next_zero_bit(cma->bitmap, bitmap_maxno, end);
2e32b947 DS	60	if (start >= cma->count)
2e32b947 DS	61	break;
d56e84b4	62	end = find_next_bit(cma->bitmap, bitmap_maxno, start);
2e32b947 DS	63	maxchunk = max(end - start, maxchunk);
	64	}
	65	mutex_unlock(&cma->lock);
	66	*val = (u64)maxchunk << cma->order_per_bit;
	67
	68	return 0;
	69	}
2e32b947 DS	70	DEFINE_SIMPLE_ATTRIBUTE(cma_maxchunk_fops, cma_maxchunk_get, NULL, "%llu\n");
2e32b947 DS	71
26b02a1f SL	72	static void cma_add_to_cma_mem_list(struct cma cma, struct cma_mem mem)
	73	{
	74	spin_lock(&cma->mem_head_lock);
	75	hlist_add_head(&mem->node, &cma->mem_head);
	76	spin_unlock(&cma->mem_head_lock);
	77	}
	78
8325330b SL	79	static struct cma_mem cma_get_entry_from_list(struct cma cma)
	80	{
	81	struct cma_mem *mem = NULL;
	82
	83	spin_lock(&cma->mem_head_lock);
	84	if (!hlist_empty(&cma->mem_head)) {
	85	mem = hlist_entry(cma->mem_head.first, struct cma_mem, node);
	86	hlist_del_init(&mem->node);
	87	}
	88	spin_unlock(&cma->mem_head_lock);
	89
	90	return mem;
	91	}
	92
	93	static int cma_free_mem(struct cma *cma, int count)
	94	{
	95	struct cma_mem *mem = NULL;
	96
	97	while (count) {
	98	mem = cma_get_entry_from_list(cma);
	99	if (mem == NULL)
	100	return 0;
	101
	102	if (mem->n <= count) {
	103	cma_release(cma, mem->p, mem->n);
	104	count -= mem->n;
	105	kfree(mem);
	106	} else if (cma->order_per_bit == 0) {
	107	cma_release(cma, mem->p, count);
	108	mem->p += count;
	109	mem->n -= count;
	110	count = 0;
	111	cma_add_to_cma_mem_list(cma, mem);
	112	} else {
	113	pr_debug("cma: cannot release partial block when order_per_bit != 0\n");
	114	cma_add_to_cma_mem_list(cma, mem);
	115	break;
	116	}
	117	}
	118
	119	return 0;
	120
	121	}
	122
	123	static int cma_free_write(void *data, u64 val)
	124	{
	125	int pages = val;
	126	struct cma *cma = data;
	127
	128	return cma_free_mem(cma, pages);
	129	}
8325330b SL	130	DEFINE_SIMPLE_ATTRIBUTE(cma_free_fops, NULL, cma_free_write, "%llu\n");
8325330b SL	131
26b02a1f SL	132	static int cma_alloc_mem(struct cma *cma, int count)
	133	{
	134	struct cma_mem *mem;
	135	struct page *p;
	136
	137	mem = kzalloc(sizeof(*mem), GFP_KERNEL);
	138	if (!mem)
	139	return -ENOMEM;
	140
875abdb6	141	p = cma_alloc(cma, count, 0);
26b02a1f SL	142	if (!p) {
	143	kfree(mem);
	144	return -ENOMEM;
	145	}
	146
	147	mem->p = p;
	148	mem->n = count;
	149
	150	cma_add_to_cma_mem_list(cma, mem);
	151
	152	return 0;
	153	}
	154
	155	static int cma_alloc_write(void *data, u64 val)
	156	{
	157	int pages = val;
	158	struct cma *cma = data;
	159
	160	return cma_alloc_mem(cma, pages);
	161	}
26b02a1f SL	162	DEFINE_SIMPLE_ATTRIBUTE(cma_alloc_fops, NULL, cma_alloc_write, "%llu\n");
26b02a1f SL	163
28b24c1f SL	164	static void cma_debugfs_add_one(struct cma *cma, int idx)
	165	{
	166	struct dentry *tmp;
	167	char name[16];
	168	int u32s;
	169
	170	sprintf(name, "cma-%d", idx);
	171
	172	tmp = debugfs_create_dir(name, cma_debugfs_root);
	173
2292c0b1	174	debugfs_create_file("alloc", S_IWUSR, tmp, cma,
26b02a1f SL	175	&cma_alloc_fops);
26b02a1f SL	176
2292c0b1	177	debugfs_create_file("free", S_IWUSR, tmp, cma,
8325330b SL	178	&cma_free_fops);
8325330b SL	179
28b24c1f SL	180	debugfs_create_file("base_pfn", S_IRUGO, tmp,
	181	&cma->base_pfn, &cma_debugfs_fops);
	182	debugfs_create_file("count", S_IRUGO, tmp,
	183	&cma->count, &cma_debugfs_fops);
	184	debugfs_create_file("order_per_bit", S_IRUGO, tmp,
26b02a1f	185	&cma->order_per_bit, &cma_debugfs_fops);
2e32b947 DS	186	debugfs_create_file("used", S_IRUGO, tmp, cma, &cma_used_fops);
2e32b947 DS	187	debugfs_create_file("maxchunk", S_IRUGO, tmp, cma, &cma_maxchunk_fops);
28b24c1f SL	188
	189	u32s = DIV_ROUND_UP(cma_bitmap_maxno(cma), BITS_PER_BYTE * sizeof(u32));
	190	debugfs_create_u32_array("bitmap", S_IRUGO, tmp, (u32*)cma->bitmap, u32s);
	191	}
	192
	193	static int __init cma_debugfs_init(void)
	194	{
	195	int i;
	196
	197	cma_debugfs_root = debugfs_create_dir("cma", NULL);
	198	if (!cma_debugfs_root)
	199	return -ENOMEM;
	200
	201	for (i = 0; i < cma_area_count; i++)
	202	cma_debugfs_add_one(&cma_areas[i], i);
	203
	204	return 0;
	205	}
	206	late_initcall(cma_debugfs_init);