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mm: cma: debugfs interface

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I've noticed that there is no interfaces exposed by CMA which would let me
fuzz what's going on in there.

This small patchset exposes some information out to userspace, plus adds
the ability to trigger allocation and freeing from userspace.

This patch (of 3):

Implement a simple debugfs interface to expose information about CMA areas
in the system.

Useful for testing/sanity checks for CMA since it was impossible to
previously retrieve this information in userspace.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Sasha Levin
2015-04-14 15:44:57 -07:00
committed by Linus Torvalds
parent 19c07d5e04
commit 28b24c1fc8
5 changed files with 90 additions and 14 deletions
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60
mm/cma_debug.c Normal file
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@@ -0,0 +1,60 @@
/*
* CMA DebugFS Interface
*
* Copyright (c) 2015 Sasha Levin <sasha.levin@oracle.com>
*/
#include <linux/debugfs.h>
#include <linux/cma.h>
#include "cma.h"
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 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("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);
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);