198 lines · c
1// SPDX-License-Identifier: GPL-2.02/*3 * CMA DebugFS Interface4 *5 * Copyright (c) 2015 Sasha Levin <sasha.levin@oracle.com>6 */7 8 9#include <linux/debugfs.h>10#include <linux/cma.h>11#include <linux/list.h>12#include <linux/kernel.h>13#include <linux/slab.h>14#include <linux/mm_types.h>15 16#include "cma.h"17 18struct cma_mem {19 struct hlist_node node;20 struct page *p;21 unsigned long n;22};23 24static int cma_debugfs_get(void *data, u64 *val)25{26 unsigned long *p = data;27 28 *val = *p;29 30 return 0;31}32DEFINE_DEBUGFS_ATTRIBUTE(cma_debugfs_fops, cma_debugfs_get, NULL, "%llu\n");33 34static int cma_used_get(void *data, u64 *val)35{36 struct cma *cma = data;37 unsigned long used;38 39 spin_lock_irq(&cma->lock);40 /* pages counter is smaller than sizeof(int) */41 used = bitmap_weight(cma->bitmap, (int)cma_bitmap_maxno(cma));42 spin_unlock_irq(&cma->lock);43 *val = (u64)used << cma->order_per_bit;44 45 return 0;46}47DEFINE_DEBUGFS_ATTRIBUTE(cma_used_fops, cma_used_get, NULL, "%llu\n");48 49static 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;54 unsigned long bitmap_maxno = cma_bitmap_maxno(cma);55 56 spin_lock_irq(&cma->lock);57 for (;;) {58 start = find_next_zero_bit(cma->bitmap, bitmap_maxno, end);59 if (start >= bitmap_maxno)60 break;61 end = find_next_bit(cma->bitmap, bitmap_maxno, start);62 maxchunk = max(end - start, maxchunk);63 }64 spin_unlock_irq(&cma->lock);65 *val = (u64)maxchunk << cma->order_per_bit;66 67 return 0;68}69DEFINE_DEBUGFS_ATTRIBUTE(cma_maxchunk_fops, cma_maxchunk_get, NULL, "%llu\n");70 71static 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 78static 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 92static 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 122static 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}129DEFINE_DEBUGFS_ATTRIBUTE(cma_free_fops, NULL, cma_free_write, "%llu\n");130 131static 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;139 140 p = cma_alloc(cma, count, 0, false);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 154static 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}161DEFINE_DEBUGFS_ATTRIBUTE(cma_alloc_fops, NULL, cma_alloc_write, "%llu\n");162 163static void cma_debugfs_add_one(struct cma *cma, struct dentry *root_dentry)164{165 struct dentry *tmp;166 167 tmp = debugfs_create_dir(cma->name, root_dentry);168 169 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);178 179 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);183}184 185static int __init cma_debugfs_init(void)186{187 struct dentry *cma_debugfs_root;188 int i;189 190 cma_debugfs_root = debugfs_create_dir("cma", NULL);191 192 for (i = 0; i < cma_area_count; i++)193 cma_debugfs_add_one(&cma_areas[i], cma_debugfs_root);194 195 return 0;196}197late_initcall(cma_debugfs_init);198