[linux-2.6-block.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->count);
	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;

	mutex_lock(&cma->lock);
	for (;;) {
		start = find_next_zero_bit(cma->bitmap, cma->count, end);
		if (start >= cma->count)
			break;
		end = find_next_bit(cma->bitmap, cma->count, 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, cma_debugfs_root, cma,
				&cma_alloc_fops);

	debugfs_create_file("free", S_IWUSR, cma_debugfs_root, 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) */
	42	used = bitmap_weight(cma->bitmap, (int)cma->count);
	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;
	55
	56	mutex_lock(&cma->lock);
	57	for (;;) {
	58	start = find_next_zero_bit(cma->bitmap, cma->count, end);
	59	if (start >= cma->count)
	60	break;
	61	end = find_next_bit(cma->bitmap, cma->count, start);
	62	maxchunk = max(end - start, maxchunk);
	63	}
	64	mutex_unlock(&cma->lock);
	65	*val = (u64)maxchunk << cma->order_per_bit;
	66
	67	return 0;
	68	}
2e32b947 DS	69	DEFINE_SIMPLE_ATTRIBUTE(cma_maxchunk_fops, cma_maxchunk_get, NULL, "%llu\n");
2e32b947 DS	70
26b02a1f SL	71	static void cma_add_to_cma_mem_list(struct cma cma, struct cma_mem mem)
	72	{
	73	spin_lock(&cma->mem_head_lock);
	74	hlist_add_head(&mem->node, &cma->mem_head);
	75	spin_unlock(&cma->mem_head_lock);
	76	}
	77
8325330b SL	78	static struct cma_mem cma_get_entry_from_list(struct cma cma)
	79	{
	80	struct cma_mem *mem = NULL;
	81
	82	spin_lock(&cma->mem_head_lock);
	83	if (!hlist_empty(&cma->mem_head)) {
	84	mem = hlist_entry(cma->mem_head.first, struct cma_mem, node);
	85	hlist_del_init(&mem->node);
	86	}
	87	spin_unlock(&cma->mem_head_lock);
	88
	89	return mem;
	90	}
	91
	92	static int cma_free_mem(struct cma *cma, int count)
	93	{
	94	struct cma_mem *mem = NULL;
	95
	96	while (count) {
	97	mem = cma_get_entry_from_list(cma);
	98	if (mem == NULL)
	99	return 0;
	100
	101	if (mem->n <= count) {
	102	cma_release(cma, mem->p, mem->n);
	103	count -= mem->n;
	104	kfree(mem);
	105	} else if (cma->order_per_bit == 0) {
	106	cma_release(cma, mem->p, count);
	107	mem->p += count;
	108	mem->n -= count;
	109	count = 0;
	110	cma_add_to_cma_mem_list(cma, mem);
	111	} else {
	112	pr_debug("cma: cannot release partial block when order_per_bit != 0\n");
	113	cma_add_to_cma_mem_list(cma, mem);
	114	break;
	115	}
	116	}
	117
	118	return 0;
	119
	120	}
	121
	122	static int cma_free_write(void *data, u64 val)
	123	{
	124	int pages = val;
	125	struct cma *cma = data;
	126
	127	return cma_free_mem(cma, pages);
	128	}
8325330b SL	129	DEFINE_SIMPLE_ATTRIBUTE(cma_free_fops, NULL, cma_free_write, "%llu\n");
8325330b SL	130
26b02a1f SL	131	static int cma_alloc_mem(struct cma *cma, int count)
	132	{
	133	struct cma_mem *mem;
	134	struct page *p;
	135
	136	mem = kzalloc(sizeof(*mem), GFP_KERNEL);
	137	if (!mem)
	138	return -ENOMEM;
	139
875abdb6	140	p = cma_alloc(cma, count, 0);
26b02a1f SL	141	if (!p) {
	142	kfree(mem);
	143	return -ENOMEM;
	144	}
	145
	146	mem->p = p;
	147	mem->n = count;
	148
	149	cma_add_to_cma_mem_list(cma, mem);
	150
	151	return 0;
	152	}
	153
	154	static int cma_alloc_write(void *data, u64 val)
	155	{
	156	int pages = val;
	157	struct cma *cma = data;
	158
	159	return cma_alloc_mem(cma, pages);
	160	}
26b02a1f SL	161	DEFINE_SIMPLE_ATTRIBUTE(cma_alloc_fops, NULL, cma_alloc_write, "%llu\n");
26b02a1f SL	162
28b24c1f SL	163	static void cma_debugfs_add_one(struct cma *cma, int idx)
	164	{
	165	struct dentry *tmp;
	166	char name[16];
	167	int u32s;
	168
	169	sprintf(name, "cma-%d", idx);
	170
	171	tmp = debugfs_create_dir(name, cma_debugfs_root);
	172
26b02a1f SL	173	debugfs_create_file("alloc", S_IWUSR, cma_debugfs_root, cma,
	174	&cma_alloc_fops);
	175
8325330b SL	176	debugfs_create_file("free", S_IWUSR, cma_debugfs_root, cma,
	177	&cma_free_fops);
	178
28b24c1f SL	179	debugfs_create_file("base_pfn", S_IRUGO, tmp,
	180	&cma->base_pfn, &cma_debugfs_fops);
	181	debugfs_create_file("count", S_IRUGO, tmp,
	182	&cma->count, &cma_debugfs_fops);
	183	debugfs_create_file("order_per_bit", S_IRUGO, tmp,
26b02a1f	184	&cma->order_per_bit, &cma_debugfs_fops);
2e32b947 DS	185	debugfs_create_file("used", S_IRUGO, tmp, cma, &cma_used_fops);
2e32b947 DS	186	debugfs_create_file("maxchunk", S_IRUGO, tmp, cma, &cma_maxchunk_fops);
28b24c1f SL	187
	188	u32s = DIV_ROUND_UP(cma_bitmap_maxno(cma), BITS_PER_BYTE * sizeof(u32));
	189	debugfs_create_u32_array("bitmap", S_IRUGO, tmp, (u32*)cma->bitmap, u32s);
	190	}
	191
	192	static int __init cma_debugfs_init(void)
	193	{
	194	int i;
	195
	196	cma_debugfs_root = debugfs_create_dir("cma", NULL);
	197	if (!cma_debugfs_root)
	198	return -ENOMEM;
	199
	200	for (i = 0; i < cma_area_count; i++)
	201	cma_debugfs_add_one(&cma_areas[i], i);
	202
	203	return 0;
	204	}
	205	late_initcall(cma_debugfs_init);