mm/cma_debug.c

/*
 * 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 "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 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 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, CONFIG_CMA_ALIGNMENT);
	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("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);