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Subject[PATCH 2/4] mm: cma: add functions to get region pages counters
Date
From: Dmitry Safonov <d.safonov@partner.samsung.com>

Here are two functions that provide interface to compute/get used size
and size of biggest free chunk in cma region.
Add that information to debugfs.

Signed-off-by: Dmitry Safonov <d.safonov@partner.samsung.com>
Signed-off-by: Stefan Strogin <s.strogin@partner.samsung.com>
---
include/linux/cma.h | 2 ++
mm/cma.c | 30 ++++++++++++++++++++++++++++++
mm/cma_debug.c | 24 ++++++++++++++++++++++++
3 files changed, 56 insertions(+)

diff --git a/include/linux/cma.h b/include/linux/cma.h
index 4c2c83c..54a2c4d 100644
--- a/include/linux/cma.h
+++ b/include/linux/cma.h
@@ -18,6 +18,8 @@ struct cma;
extern unsigned long totalcma_pages;
extern phys_addr_t cma_get_base(struct cma *cma);
extern unsigned long cma_get_size(struct cma *cma);
+extern unsigned long cma_get_used(struct cma *cma);
+extern unsigned long cma_get_maxchunk(struct cma *cma);

extern int __init cma_declare_contiguous(phys_addr_t base,
phys_addr_t size, phys_addr_t limit,
diff --git a/mm/cma.c b/mm/cma.c
index ed269b0..95e8121 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -54,6 +54,36 @@ unsigned long cma_get_size(struct cma *cma)
return cma->count << PAGE_SHIFT;
}

+unsigned long cma_get_used(struct cma *cma)
+{
+ unsigned long ret = 0;
+
+ mutex_lock(&cma->lock);
+ /* pages counter is smaller than sizeof(int) */
+ ret = bitmap_weight(cma->bitmap, (int)cma->count);
+ mutex_unlock(&cma->lock);
+
+ return ret;
+}
+
+unsigned long cma_get_maxchunk(struct cma *cma)
+{
+ unsigned long maxchunk = 0;
+ unsigned long start, end = 0;
+
+ mutex_lock(&cma->lock);
+ for (;;) {
+ start = find_next_zero_bit(cma->bitmap, cma->count, end);
+ if (start >= cma->count)
+ break;
+ end = find_next_bit(cma->bitmap, cma->count, start);
+ maxchunk = max(end - start, maxchunk);
+ }
+ mutex_unlock(&cma->lock);
+
+ return maxchunk;
+}
+
static unsigned long cma_bitmap_aligned_mask(struct cma *cma, int align_order)
{
if (align_order <= cma->order_per_bit)
diff --git a/mm/cma_debug.c b/mm/cma_debug.c
index 5acd937..9705e86 100644
--- a/mm/cma_debug.c
+++ b/mm/cma_debug.c
@@ -128,6 +128,28 @@ static int cma_debugfs_get(void *data, u64 *val)

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;
+
+ *val = cma_get_used(cma);
+
+ 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;
+
+ *val = cma_get_maxchunk(cma);
+
+ 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);
@@ -289,6 +311,8 @@ static void cma_debugfs_add_one(struct cma *cma, int idx)
&cma->count, &cma_debugfs_fops);
debugfs_create_file("order_per_bit", S_IRUGO, tmp,
&cma->order_per_bit, &cma_debugfs_fops);
+ debugfs_create_file("used", S_IRUGO, tmp, cma, &cma_used_fops);
+ debugfs_create_file("maxchunk", S_IRUGO, tmp, cma, &cma_maxchunk_fops);

debugfs_create_file("buffers", S_IRUGO, tmp, cma, &cma_buffers_fops);

--
2.1.0


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