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authorSasha Levin <sasha.levin@oracle.com>2015-04-14 15:44:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-14 16:49:00 -0700
commit28b24c1fc8c22cabe5b8a16ffe6a61dfce51a1f2 (patch)
tree2a6127decc749a3aea6a50123855ba73013fd082 /mm/cma_debug.c
parent19c07d5e0414261bd7ec3d8419dd26f468ef69d9 (diff)
downloadlinux-28b24c1fc8c22cabe5b8a16ffe6a61dfce51a1f2.tar.bz2
mm: cma: debugfs interface
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>
Diffstat (limited to 'mm/cma_debug.c')
-rw-r--r--mm/cma_debug.c60
1 files changed, 60 insertions, 0 deletions
diff --git a/mm/cma_debug.c b/mm/cma_debug.c
new file mode 100644
index 000000000000..3af2de6d4e5f
--- /dev/null
+++ b/mm/cma_debug.c
@@ -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);