[linux.git] / mm / cma_debug.c

// SPDX-License-Identifier: GPL-2.0
/*
 * CMA DebugFS Interface
 *
 * Copyright (c) 2015 Sasha Levin <[email protected]>
 */


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

	*val = *p;

	return 0;
}
DEFINE_DEBUGFS_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;

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

	return 0;
}
DEFINE_DEBUGFS_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);

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

	return 0;
}
DEFINE_DEBUGFS_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_DEBUGFS_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, false);
	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_DEBUGFS_ATTRIBUTE(cma_alloc_fops, NULL, cma_alloc_write, "%llu\n");

static void cma_debugfs_add_one(struct cma *cma, struct dentry *root_dentry)
{
	struct dentry *tmp;

	tmp = debugfs_create_dir(cma->name, root_dentry);

	debugfs_create_file("alloc", 0200, tmp, cma, &cma_alloc_fops);
	debugfs_create_file("free", 0200, tmp, cma, &cma_free_fops);
	debugfs_create_file("base_pfn", 0444, tmp,
			    &cma->base_pfn, &cma_debugfs_fops);
	debugfs_create_file("count", 0444, tmp, &cma->count, &cma_debugfs_fops);
	debugfs_create_file("order_per_bit", 0444, tmp,
			    &cma->order_per_bit, &cma_debugfs_fops);
	debugfs_create_file("used", 0444, tmp, cma, &cma_used_fops);
	debugfs_create_file("maxchunk", 0444, tmp, cma, &cma_maxchunk_fops);

	cma->dfs_bitmap.array = (u32 *)cma->bitmap;
	cma->dfs_bitmap.n_elements = DIV_ROUND_UP(cma_bitmap_maxno(cma),
						  BITS_PER_BYTE * sizeof(u32));
	debugfs_create_u32_array("bitmap", 0444, tmp, &cma->dfs_bitmap);
}

static int __init cma_debugfs_init(void)
{
	struct dentry *cma_debugfs_root;
	int i;

	cma_debugfs_root = debugfs_create_dir("cma", NULL);

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

	return 0;
}
late_initcall(cma_debugfs_init);
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
28b24c1f SL	2	/*
	3	* CMA DebugFS Interface
	4	*
	5	* Copyright (c) 2015 Sasha Levin <[email protected]>
	6	*/
	7
	8
	9	#include <linux/debugfs.h>
	10	#include <linux/cma.h>
26b02a1f SL	11	#include <linux/list.h>
	12	#include <linux/kernel.h>
	13	#include <linux/slab.h>
8325330b	14	#include <linux/mm_types.h>
28b24c1f SL	15
	16	#include "cma.h"
	17
26b02a1f SL	18	struct cma_mem {
	19	struct hlist_node node;
	20	struct page *p;
	21	unsigned long n;
	22	};
	23
28b24c1f SL	24	static int cma_debugfs_get(void data, u64 val)
	25	{
	26	unsigned long *p = data;
	27
	28	val = p;
	29
	30	return 0;
	31	}
a9ea242a	32	DEFINE_DEBUGFS_ATTRIBUTE(cma_debugfs_fops, cma_debugfs_get, NULL, "%llu\n");
28b24c1f	33
2e32b947 DS	34	static int cma_used_get(void data, u64 val)
	35	{
	36	struct cma *cma = data;
	37	unsigned long used;
	38
0ef7dcac	39	spin_lock_irq(&cma->lock);
2e32b947	40	/* pages counter is smaller than sizeof(int) */
d56e84b4	41	used = bitmap_weight(cma->bitmap, (int)cma_bitmap_maxno(cma));
0ef7dcac	42	spin_unlock_irq(&cma->lock);
2e32b947 DS	43	*val = (u64)used << cma->order_per_bit;
	44
	45	return 0;
	46	}
a9ea242a	47	DEFINE_DEBUGFS_ATTRIBUTE(cma_used_fops, cma_used_get, NULL, "%llu\n");
2e32b947 DS	48
	49	static int cma_maxchunk_get(void data, u64 val)
	50	{
	51	struct cma *cma = data;
	52	unsigned long maxchunk = 0;
	53	unsigned long start, end = 0;
d56e84b4	54	unsigned long bitmap_maxno = cma_bitmap_maxno(cma);
2e32b947	55
0ef7dcac	56	spin_lock_irq(&cma->lock);
2e32b947	57	for (;;) {
d56e84b4	58	start = find_next_zero_bit(cma->bitmap, bitmap_maxno, end);
f0fd5050	59	if (start >= bitmap_maxno)
2e32b947	60	break;
d56e84b4	61	end = find_next_bit(cma->bitmap, bitmap_maxno, start);
2e32b947 DS	62	maxchunk = max(end - start, maxchunk);
2e32b947 DS	63	}
0ef7dcac	64	spin_unlock_irq(&cma->lock);
2e32b947 DS	65	*val = (u64)maxchunk << cma->order_per_bit;
	66
	67	return 0;
	68	}
a9ea242a	69	DEFINE_DEBUGFS_ATTRIBUTE(cma_maxchunk_fops, cma_maxchunk_get, NULL, "%llu\n");
2e32b947	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	}
a9ea242a	129	DEFINE_DEBUGFS_ATTRIBUTE(cma_free_fops, NULL, cma_free_write, "%llu\n");
8325330b	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
65182029	140	p = cma_alloc(cma, count, 0, false);
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	}
a9ea242a	161	DEFINE_DEBUGFS_ATTRIBUTE(cma_alloc_fops, NULL, cma_alloc_write, "%llu\n");
26b02a1f	162
5a7f1b2f	163	static void cma_debugfs_add_one(struct cma cma, struct dentry root_dentry)
28b24c1f SL	164	{
28b24c1f SL	165	struct dentry *tmp;
28b24c1f	166
9a79443d	167	tmp = debugfs_create_dir(cma->name, root_dentry);
28b24c1f	168
0825a6f9 JP	169	debugfs_create_file("alloc", 0200, tmp, cma, &cma_alloc_fops);
	170	debugfs_create_file("free", 0200, tmp, cma, &cma_free_fops);
	171	debugfs_create_file("base_pfn", 0444, tmp,
	172	&cma->base_pfn, &cma_debugfs_fops);
	173	debugfs_create_file("count", 0444, tmp, &cma->count, &cma_debugfs_fops);
	174	debugfs_create_file("order_per_bit", 0444, tmp,
	175	&cma->order_per_bit, &cma_debugfs_fops);
	176	debugfs_create_file("used", 0444, tmp, cma, &cma_used_fops);
	177	debugfs_create_file("maxchunk", 0444, tmp, cma, &cma_maxchunk_fops);
28b24c1f	178
a2b992c8 JK	179	cma->dfs_bitmap.array = (u32 *)cma->bitmap;
	180	cma->dfs_bitmap.n_elements = DIV_ROUND_UP(cma_bitmap_maxno(cma),
	181	BITS_PER_BYTE * sizeof(u32));
	182	debugfs_create_u32_array("bitmap", 0444, tmp, &cma->dfs_bitmap);
28b24c1f SL	183	}
	184
	185	static int __init cma_debugfs_init(void)
	186	{
5a7f1b2f	187	struct dentry *cma_debugfs_root;
28b24c1f SL	188	int i;
	189
	190	cma_debugfs_root = debugfs_create_dir("cma", NULL);
28b24c1f SL	191
28b24c1f SL	192	for (i = 0; i < cma_area_count; i++)
5a7f1b2f	193	cma_debugfs_add_one(&cma_areas[i], cma_debugfs_root);
28b24c1f SL	194
	195	return 0;
	196	}
	197	late_initcall(cma_debugfs_init);