diff options
Diffstat (limited to 'mm/cma_debug.c')
| -rw-r--r-- | mm/cma_debug.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/mm/cma_debug.c b/mm/cma_debug.c new file mode 100644 index 000000000..3e0415076 --- /dev/null +++ b/mm/cma_debug.c @@ -0,0 +1,202 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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 >= bitmap_maxno) + 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, 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_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; + + scnprintf(name, sizeof(name), "cma-%s", cma->name); + + tmp = debugfs_create_dir(name, cma_debugfs_root); + + 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); + + u32s = DIV_ROUND_UP(cma_bitmap_maxno(cma), BITS_PER_BYTE * sizeof(u32)); + debugfs_create_u32_array("bitmap", 0444, 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); |