mm: cma: add functions to get region pages counters

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 <stefan.strogin@gmail.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pintu Kumar <pintu.k@samsung.com>
Cc: Weijie Yang <weijie.yang@samsung.com>
Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Cc: Vyacheslav Tyrtov <v.tyrtov@samsung.com>
Cc: Aleksei Mateosian <a.mateosian@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/cma.h b/include/linux/cma.h
index f7ef093ec49a2bbdd637aae6ab0f1bf0fa4e1e32..1231f50f865e28637ee30d3abbe3e25f39691762 100644 (file)
--- 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(const struct cma *cma);
 extern unsigned long cma_get_size(const 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 3a7a67b933942f5232091094f5d719d59bda13ab..d839011e8c6f41a9bb45cfc47b901381fdf56605 100644 (file)
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -53,6 +53,36 @@ unsigned long cma_get_size(const 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 << cma->order_per_bit;
+}
+
+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 << cma->order_per_bit;
+}
+
 static unsigned long cma_bitmap_aligned_mask(const struct cma *cma,
                                             int align_order)
 {

diff --git a/mm/cma_debug.c b/mm/cma_debug.c
index ec915e6f17ee93ffe223e2c5854d76c0bc2bbb24..984ceddf8d31e907a052c4c1754c9c94762a4acf 100644 (file)
--- a/mm/cma_debug.c
+++ b/mm/cma_debug.c
@@ -33,6 +33,28 @@ 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);
@@ -149,6 +171,8 @@ 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);
 
        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);