/*
* Copyright (C) 2017 Facebook
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#include <linux/kernel.h>
#include <linux/blkdev.h>
#include <linux/debugfs.h>
#include <linux/blk-mq.h>
#include "blk-mq.h"
struct blk_mq_debugfs_attr {
const char *name;
umode_t mode;
const struct file_operations *fops;
};
static struct dentry *block_debugfs_root;
static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
};
static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
};
int blk_mq_debugfs_register(struct request_queue *q, const char *name)
{
if (!block_debugfs_root)
return -ENOENT;
q->debugfs_dir = debugfs_create_dir(name, block_debugfs_root);
if (!q->debugfs_dir)
goto err;
if (blk_mq_debugfs_register_hctxs(q))
goto err;
return 0;
err:
blk_mq_debugfs_unregister(q);
return -ENOMEM;
}
void blk_mq_debugfs_unregister(struct request_queue *q)
{
debugfs_remove_recursive(q->debugfs_dir);
q->mq_debugfs_dir = NULL;
q->debugfs_dir = NULL;
}
static int blk_mq_debugfs_register_ctx(struct request_queue *q,
struct blk_mq_ctx *ctx,
struct dentry *hctx_dir)
{
struct dentry *ctx_dir;
char name[20];
int i;
snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
ctx_dir = debugfs_create_dir(name, hctx_dir);
if (!ctx_dir)
return -ENOMEM;
for (i = 0; i < ARRAY_SIZE(blk_mq_debugfs_ctx_attrs); i++) {
const struct blk_mq_debugfs_attr *attr;
attr = &blk_mq_debugfs_ctx_attrs[i];
if (!debugfs_create_file(attr->name, attr->mode, ctx_dir, ctx,
attr->fops))
return -ENOMEM;
}
return 0;
}
static int blk_mq_debugfs_register_hctx(struct request_queue *q,
struct blk_mq_hw_ctx *hctx)
{
struct blk_mq_ctx *ctx;
struct dentry *hctx_dir;
char name[20];
int i;
snprintf(name, sizeof(name), "%u", hctx->queue_num);
hctx_dir = debugfs_create_dir(name, q->mq_debugfs_dir);
if (!hctx_dir)
return -ENOMEM;
for (i = 0; i < ARRAY_SIZE(blk_mq_debugfs_hctx_attrs); i++) {
const struct blk_mq_debugfs_attr *attr;
attr = &blk_mq_debugfs_hctx_attrs[i];
if (!debugfs_create_file(attr->name, attr->mode, hctx_dir, hctx,
attr->fops))
return -ENOMEM;
}
hctx_for_each_ctx(hctx, ctx, i) {
if (blk_mq_debugfs_register_ctx(q, ctx, hctx_dir))
return -ENOMEM;
}
return 0;
}
int blk_mq_debugfs_register_hctxs(struct request_queue *q)
{
struct blk_mq_hw_ctx *hctx;
int i;
if (!q->debugfs_dir)
return -ENOENT;
q->mq_debugfs_dir = debugfs_create_dir("mq", q->debugfs_dir);
if (!q->mq_debugfs_dir)
goto err;
queue_for_each_hw_ctx(q, hctx, i) {
if (blk_mq_debugfs_register_hctx(q, hctx))
goto err;
}
return 0;
err:
blk_mq_debugfs_unregister_hctxs(q);
return -ENOMEM;
}
void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
{
debugfs_remove_recursive(q->mq_debugfs_dir);
q->mq_debugfs_dir = NULL;
}
void blk_mq_debugfs_init(void)
{
block_debugfs_root = debugfs_create_dir("block", NULL);
}
