1 files changed, 197 insertions, 0 deletions
diff --git a/mm/cma_debug.c b/mm/cma_debug.c
new file mode 100644
index 0000000000..602fff89b1
--- /dev/null
+++ b/mm/cma_debug.c
@@ -0,0 +1,197 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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 int cma_debugfs_get(void *data, u64 *val)
+{
+	unsigned long *p = data;
+
+	*val = *p;
+
+	return 0;
+}
+DEFINE_DEBUGFS_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;
+
+	spin_lock_irq(&cma->lock);
+	/* pages counter is smaller than sizeof(int) */
+	used = bitmap_weight(cma->bitmap, (int)cma_bitmap_maxno(cma));
+	spin_unlock_irq(&cma->lock);
+	*val = (u64)used << cma->order_per_bit;
+
+	return 0;
+}
+DEFINE_DEBUGFS_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;
+	unsigned long bitmap_maxno = cma_bitmap_maxno(cma);
+
+	spin_lock_irq(&cma->lock);
+	for (;;) {
+		start = find_next_zero_bit(cma->bitmap, bitmap_maxno, end);
+		if (start >= bitmap_maxno)
+			break;
+		end = find_next_bit(cma->bitmap, bitmap_maxno, start);
+		maxchunk = max(end - start, maxchunk);
+	}
+	spin_unlock_irq(&cma->lock);
+	*val = (u64)maxchunk << cma->order_per_bit;
+
+	return 0;
+}
+DEFINE_DEBUGFS_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_DEBUGFS_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, false);
+	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_DEBUGFS_ATTRIBUTE(cma_alloc_fops, NULL, cma_alloc_write, "%llu\n");
+
+static void cma_debugfs_add_one(struct cma *cma, struct dentry *root_dentry)
+{
+	struct dentry *tmp;
+
+	tmp = debugfs_create_dir(cma->name, root_dentry);
+
+	debugfs_create_file("alloc", 0200, tmp, cma, &cma_alloc_fops);
+	debugfs_create_file("free", 0200, tmp, cma, &cma_free_fops);
+	debugfs_create_file("base_pfn", 0444, tmp,
+			    &cma->base_pfn, &cma_debugfs_fops);
+	debugfs_create_file("count", 0444, tmp, &cma->count, &cma_debugfs_fops);
+	debugfs_create_file("order_per_bit", 0444, tmp,
+			    &cma->order_per_bit, &cma_debugfs_fops);
+	debugfs_create_file("used", 0444, tmp, cma, &cma_used_fops);
+	debugfs_create_file("maxchunk", 0444, tmp, cma, &cma_maxchunk_fops);
+
+	cma->dfs_bitmap.array = (u32 *)cma->bitmap;
+	cma->dfs_bitmap.n_elements = DIV_ROUND_UP(cma_bitmap_maxno(cma),
+						  BITS_PER_BYTE * sizeof(u32));
+	debugfs_create_u32_array("bitmap", 0444, tmp, &cma->dfs_bitmap);
+}
+
+static int __init cma_debugfs_init(void)
+{
+	struct dentry *cma_debugfs_root;
+	int i;
+
+	cma_debugfs_root = debugfs_create_dir("cma", NULL);
+
+	for (i = 0; i < cma_area_count; i++)
+		cma_debugfs_add_one(&cma_areas[i], cma_debugfs_root);
+
+	return 0;
+}
+late_initcall(cma_debugfs_init);