Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / mm / cma_debug.c

diff --git a/kernel/mm/cma_debug.c b/kernel/mm/cma_debug.c
new file mode 100644 (file)
index 0000000..7621ee3
--- /dev/null
+++ b/kernel/mm/cma_debug.c
@@ -0,0 +1,205 @@
+/*
+ * 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->count);
+       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;
+
+       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);
+       *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);
+       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;
+
+       sprintf(name, "cma-%d", idx);
+
+       tmp = debugfs_create_dir(name, cma_debugfs_root);
+
+       debugfs_create_file("alloc", S_IWUSR, cma_debugfs_root, cma,
+                               &cma_alloc_fops);
+
+       debugfs_create_file("free", S_IWUSR, cma_debugfs_root, cma,
+                               &cma_free_fops);
+
+       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);
+       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);
+}
+
+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);