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linux-next/drivers/mmc/card/block.c
Christoph Hellwig 65299a3b78 block: separate priority boosting from REQ_META
Add a new REQ_PRIO to let requests preempt others in the cfq I/O schedule,
and lave REQ_META purely for marking requests as metadata in blktrace.

All existing callers of REQ_META except for XFS are updated to also
set REQ_PRIO for now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-08-23 14:50:29 +02:00

1643 lines
40 KiB
C

/*
* Block driver for media (i.e., flash cards)
*
* Copyright 2002 Hewlett-Packard Company
* Copyright 2005-2008 Pierre Ossman
*
* Use consistent with the GNU GPL is permitted,
* provided that this copyright notice is
* preserved in its entirety in all copies and derived works.
*
* HEWLETT-PACKARD COMPANY MAKES NO WARRANTIES, EXPRESSED OR IMPLIED,
* AS TO THE USEFULNESS OR CORRECTNESS OF THIS CODE OR ITS
* FITNESS FOR ANY PARTICULAR PURPOSE.
*
* Many thanks to Alessandro Rubini and Jonathan Corbet!
*
* Author: Andrew Christian
* 28 May 2002
*/
#include <linux/moduleparam.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/hdreg.h>
#include <linux/kdev_t.h>
#include <linux/blkdev.h>
#include <linux/mutex.h>
#include <linux/scatterlist.h>
#include <linux/string_helpers.h>
#include <linux/delay.h>
#include <linux/capability.h>
#include <linux/compat.h>
#include <linux/mmc/ioctl.h>
#include <linux/mmc/card.h>
#include <linux/mmc/host.h>
#include <linux/mmc/mmc.h>
#include <linux/mmc/sd.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include "queue.h"
MODULE_ALIAS("mmc:block");
#ifdef MODULE_PARAM_PREFIX
#undef MODULE_PARAM_PREFIX
#endif
#define MODULE_PARAM_PREFIX "mmcblk."
#define INAND_CMD38_ARG_EXT_CSD 113
#define INAND_CMD38_ARG_ERASE 0x00
#define INAND_CMD38_ARG_TRIM 0x01
#define INAND_CMD38_ARG_SECERASE 0x80
#define INAND_CMD38_ARG_SECTRIM1 0x81
#define INAND_CMD38_ARG_SECTRIM2 0x88
static DEFINE_MUTEX(block_mutex);
/*
* The defaults come from config options but can be overriden by module
* or bootarg options.
*/
static int perdev_minors = CONFIG_MMC_BLOCK_MINORS;
/*
* We've only got one major, so number of mmcblk devices is
* limited to 256 / number of minors per device.
*/
static int max_devices;
/* 256 minors, so at most 256 separate devices */
static DECLARE_BITMAP(dev_use, 256);
static DECLARE_BITMAP(name_use, 256);
/*
* There is one mmc_blk_data per slot.
*/
struct mmc_blk_data {
spinlock_t lock;
struct gendisk *disk;
struct mmc_queue queue;
struct list_head part;
unsigned int flags;
#define MMC_BLK_CMD23 (1 << 0) /* Can do SET_BLOCK_COUNT for multiblock */
#define MMC_BLK_REL_WR (1 << 1) /* MMC Reliable write support */
unsigned int usage;
unsigned int read_only;
unsigned int part_type;
unsigned int name_idx;
/*
* Only set in main mmc_blk_data associated
* with mmc_card with mmc_set_drvdata, and keeps
* track of the current selected device partition.
*/
unsigned int part_curr;
struct device_attribute force_ro;
};
static DEFINE_MUTEX(open_lock);
enum mmc_blk_status {
MMC_BLK_SUCCESS = 0,
MMC_BLK_PARTIAL,
MMC_BLK_RETRY,
MMC_BLK_RETRY_SINGLE,
MMC_BLK_DATA_ERR,
MMC_BLK_CMD_ERR,
MMC_BLK_ABORT,
};
module_param(perdev_minors, int, 0444);
MODULE_PARM_DESC(perdev_minors, "Minors numbers to allocate per device");
static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
{
struct mmc_blk_data *md;
mutex_lock(&open_lock);
md = disk->private_data;
if (md && md->usage == 0)
md = NULL;
if (md)
md->usage++;
mutex_unlock(&open_lock);
return md;
}
static inline int mmc_get_devidx(struct gendisk *disk)
{
int devmaj = MAJOR(disk_devt(disk));
int devidx = MINOR(disk_devt(disk)) / perdev_minors;
if (!devmaj)
devidx = disk->first_minor / perdev_minors;
return devidx;
}
static void mmc_blk_put(struct mmc_blk_data *md)
{
mutex_lock(&open_lock);
md->usage--;
if (md->usage == 0) {
int devidx = mmc_get_devidx(md->disk);
blk_cleanup_queue(md->queue.queue);
__clear_bit(devidx, dev_use);
put_disk(md->disk);
kfree(md);
}
mutex_unlock(&open_lock);
}
static ssize_t force_ro_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
int ret;
struct mmc_blk_data *md = mmc_blk_get(dev_to_disk(dev));
ret = snprintf(buf, PAGE_SIZE, "%d",
get_disk_ro(dev_to_disk(dev)) ^
md->read_only);
mmc_blk_put(md);
return ret;
}
static ssize_t force_ro_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
int ret;
char *end;
struct mmc_blk_data *md = mmc_blk_get(dev_to_disk(dev));
unsigned long set = simple_strtoul(buf, &end, 0);
if (end == buf) {
ret = -EINVAL;
goto out;
}
set_disk_ro(dev_to_disk(dev), set || md->read_only);
ret = count;
out:
mmc_blk_put(md);
return ret;
}
static int mmc_blk_open(struct block_device *bdev, fmode_t mode)
{
struct mmc_blk_data *md = mmc_blk_get(bdev->bd_disk);
int ret = -ENXIO;
mutex_lock(&block_mutex);
if (md) {
if (md->usage == 2)
check_disk_change(bdev);
ret = 0;
if ((mode & FMODE_WRITE) && md->read_only) {
mmc_blk_put(md);
ret = -EROFS;
}
}
mutex_unlock(&block_mutex);
return ret;
}
static int mmc_blk_release(struct gendisk *disk, fmode_t mode)
{
struct mmc_blk_data *md = disk->private_data;
mutex_lock(&block_mutex);
mmc_blk_put(md);
mutex_unlock(&block_mutex);
return 0;
}
static int
mmc_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
geo->cylinders = get_capacity(bdev->bd_disk) / (4 * 16);
geo->heads = 4;
geo->sectors = 16;
return 0;
}
struct mmc_blk_ioc_data {
struct mmc_ioc_cmd ic;
unsigned char *buf;
u64 buf_bytes;
};
static struct mmc_blk_ioc_data *mmc_blk_ioctl_copy_from_user(
struct mmc_ioc_cmd __user *user)
{
struct mmc_blk_ioc_data *idata;
int err;
idata = kzalloc(sizeof(*idata), GFP_KERNEL);
if (!idata) {
err = -ENOMEM;
goto out;
}
if (copy_from_user(&idata->ic, user, sizeof(idata->ic))) {
err = -EFAULT;
goto idata_err;
}
idata->buf_bytes = (u64) idata->ic.blksz * idata->ic.blocks;
if (idata->buf_bytes > MMC_IOC_MAX_BYTES) {
err = -EOVERFLOW;
goto idata_err;
}
idata->buf = kzalloc(idata->buf_bytes, GFP_KERNEL);
if (!idata->buf) {
err = -ENOMEM;
goto idata_err;
}
if (copy_from_user(idata->buf, (void __user *)(unsigned long)
idata->ic.data_ptr, idata->buf_bytes)) {
err = -EFAULT;
goto copy_err;
}
return idata;
copy_err:
kfree(idata->buf);
idata_err:
kfree(idata);
out:
return ERR_PTR(err);
}
static int mmc_blk_ioctl_cmd(struct block_device *bdev,
struct mmc_ioc_cmd __user *ic_ptr)
{
struct mmc_blk_ioc_data *idata;
struct mmc_blk_data *md;
struct mmc_card *card;
struct mmc_command cmd = {0};
struct mmc_data data = {0};
struct mmc_request mrq = {0};
struct scatterlist sg;
int err;
/*
* The caller must have CAP_SYS_RAWIO, and must be calling this on the
* whole block device, not on a partition. This prevents overspray
* between sibling partitions.
*/
if ((!capable(CAP_SYS_RAWIO)) || (bdev != bdev->bd_contains))
return -EPERM;
idata = mmc_blk_ioctl_copy_from_user(ic_ptr);
if (IS_ERR(idata))
return PTR_ERR(idata);
cmd.opcode = idata->ic.opcode;
cmd.arg = idata->ic.arg;
cmd.flags = idata->ic.flags;
data.sg = &sg;
data.sg_len = 1;
data.blksz = idata->ic.blksz;
data.blocks = idata->ic.blocks;
sg_init_one(data.sg, idata->buf, idata->buf_bytes);
if (idata->ic.write_flag)
data.flags = MMC_DATA_WRITE;
else
data.flags = MMC_DATA_READ;
mrq.cmd = &cmd;
mrq.data = &data;
md = mmc_blk_get(bdev->bd_disk);
if (!md) {
err = -EINVAL;
goto cmd_done;
}
card = md->queue.card;
if (IS_ERR(card)) {
err = PTR_ERR(card);
goto cmd_done;
}
mmc_claim_host(card->host);
if (idata->ic.is_acmd) {
err = mmc_app_cmd(card->host, card);
if (err)
goto cmd_rel_host;
}
/* data.flags must already be set before doing this. */
mmc_set_data_timeout(&data, card);
/* Allow overriding the timeout_ns for empirical tuning. */
if (idata->ic.data_timeout_ns)
data.timeout_ns = idata->ic.data_timeout_ns;
if ((cmd.flags & MMC_RSP_R1B) == MMC_RSP_R1B) {
/*
* Pretend this is a data transfer and rely on the host driver
* to compute timeout. When all host drivers support
* cmd.cmd_timeout for R1B, this can be changed to:
*
* mrq.data = NULL;
* cmd.cmd_timeout = idata->ic.cmd_timeout_ms;
*/
data.timeout_ns = idata->ic.cmd_timeout_ms * 1000000;
}
mmc_wait_for_req(card->host, &mrq);
if (cmd.error) {
dev_err(mmc_dev(card->host), "%s: cmd error %d\n",
__func__, cmd.error);
err = cmd.error;
goto cmd_rel_host;
}
if (data.error) {
dev_err(mmc_dev(card->host), "%s: data error %d\n",
__func__, data.error);
err = data.error;
goto cmd_rel_host;
}
/*
* According to the SD specs, some commands require a delay after
* issuing the command.
*/
if (idata->ic.postsleep_min_us)
usleep_range(idata->ic.postsleep_min_us, idata->ic.postsleep_max_us);
if (copy_to_user(&(ic_ptr->response), cmd.resp, sizeof(cmd.resp))) {
err = -EFAULT;
goto cmd_rel_host;
}
if (!idata->ic.write_flag) {
if (copy_to_user((void __user *)(unsigned long) idata->ic.data_ptr,
idata->buf, idata->buf_bytes)) {
err = -EFAULT;
goto cmd_rel_host;
}
}
cmd_rel_host:
mmc_release_host(card->host);
cmd_done:
mmc_blk_put(md);
kfree(idata->buf);
kfree(idata);
return err;
}
static int mmc_blk_ioctl(struct block_device *bdev, fmode_t mode,
unsigned int cmd, unsigned long arg)
{
int ret = -EINVAL;
if (cmd == MMC_IOC_CMD)
ret = mmc_blk_ioctl_cmd(bdev, (struct mmc_ioc_cmd __user *)arg);
return ret;
}
#ifdef CONFIG_COMPAT
static int mmc_blk_compat_ioctl(struct block_device *bdev, fmode_t mode,
unsigned int cmd, unsigned long arg)
{
return mmc_blk_ioctl(bdev, mode, cmd, (unsigned long) compat_ptr(arg));
}
#endif
static const struct block_device_operations mmc_bdops = {
.open = mmc_blk_open,
.release = mmc_blk_release,
.getgeo = mmc_blk_getgeo,
.owner = THIS_MODULE,
.ioctl = mmc_blk_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = mmc_blk_compat_ioctl,
#endif
};
static inline int mmc_blk_part_switch(struct mmc_card *card,
struct mmc_blk_data *md)
{
int ret;
struct mmc_blk_data *main_md = mmc_get_drvdata(card);
if (main_md->part_curr == md->part_type)
return 0;
if (mmc_card_mmc(card)) {
card->ext_csd.part_config &= ~EXT_CSD_PART_CONFIG_ACC_MASK;
card->ext_csd.part_config |= md->part_type;
ret = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
EXT_CSD_PART_CONFIG, card->ext_csd.part_config,
card->ext_csd.part_time);
if (ret)
return ret;
}
main_md->part_curr = md->part_type;
return 0;
}
static u32 mmc_sd_num_wr_blocks(struct mmc_card *card)
{
int err;
u32 result;
__be32 *blocks;
struct mmc_request mrq = {0};
struct mmc_command cmd = {0};
struct mmc_data data = {0};
unsigned int timeout_us;
struct scatterlist sg;
cmd.opcode = MMC_APP_CMD;
cmd.arg = card->rca << 16;
cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
err = mmc_wait_for_cmd(card->host, &cmd, 0);
if (err)
return (u32)-1;
if (!mmc_host_is_spi(card->host) && !(cmd.resp[0] & R1_APP_CMD))
return (u32)-1;
memset(&cmd, 0, sizeof(struct mmc_command));
cmd.opcode = SD_APP_SEND_NUM_WR_BLKS;
cmd.arg = 0;
cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
data.timeout_ns = card->csd.tacc_ns * 100;
data.timeout_clks = card->csd.tacc_clks * 100;
timeout_us = data.timeout_ns / 1000;
timeout_us += data.timeout_clks * 1000 /
(card->host->ios.clock / 1000);
if (timeout_us > 100000) {
data.timeout_ns = 100000000;
data.timeout_clks = 0;
}
data.blksz = 4;
data.blocks = 1;
data.flags = MMC_DATA_READ;
data.sg = &sg;
data.sg_len = 1;
mrq.cmd = &cmd;
mrq.data = &data;
blocks = kmalloc(4, GFP_KERNEL);
if (!blocks)
return (u32)-1;
sg_init_one(&sg, blocks, 4);
mmc_wait_for_req(card->host, &mrq);
result = ntohl(*blocks);
kfree(blocks);
if (cmd.error || data.error)
result = (u32)-1;
return result;
}
static int send_stop(struct mmc_card *card, u32 *status)
{
struct mmc_command cmd = {0};
int err;
cmd.opcode = MMC_STOP_TRANSMISSION;
cmd.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
err = mmc_wait_for_cmd(card->host, &cmd, 5);
if (err == 0)
*status = cmd.resp[0];
return err;
}
static int get_card_status(struct mmc_card *card, u32 *status, int retries)
{
struct mmc_command cmd = {0};
int err;
cmd.opcode = MMC_SEND_STATUS;
if (!mmc_host_is_spi(card->host))
cmd.arg = card->rca << 16;
cmd.flags = MMC_RSP_SPI_R2 | MMC_RSP_R1 | MMC_CMD_AC;
err = mmc_wait_for_cmd(card->host, &cmd, retries);
if (err == 0)
*status = cmd.resp[0];
return err;
}
#define ERR_RETRY 2
#define ERR_ABORT 1
#define ERR_CONTINUE 0
static int mmc_blk_cmd_error(struct request *req, const char *name, int error,
bool status_valid, u32 status)
{
switch (error) {
case -EILSEQ:
/* response crc error, retry the r/w cmd */
pr_err("%s: %s sending %s command, card status %#x\n",
req->rq_disk->disk_name, "response CRC error",
name, status);
return ERR_RETRY;
case -ETIMEDOUT:
pr_err("%s: %s sending %s command, card status %#x\n",
req->rq_disk->disk_name, "timed out", name, status);
/* If the status cmd initially failed, retry the r/w cmd */
if (!status_valid)
return ERR_RETRY;
/*
* If it was a r/w cmd crc error, or illegal command
* (eg, issued in wrong state) then retry - we should
* have corrected the state problem above.
*/
if (status & (R1_COM_CRC_ERROR | R1_ILLEGAL_COMMAND))
return ERR_RETRY;
/* Otherwise abort the command */
return ERR_ABORT;
default:
/* We don't understand the error code the driver gave us */
pr_err("%s: unknown error %d sending read/write command, card status %#x\n",
req->rq_disk->disk_name, error, status);
return ERR_ABORT;
}
}
/*
* Initial r/w and stop cmd error recovery.
* We don't know whether the card received the r/w cmd or not, so try to
* restore things back to a sane state. Essentially, we do this as follows:
* - Obtain card status. If the first attempt to obtain card status fails,
* the status word will reflect the failed status cmd, not the failed
* r/w cmd. If we fail to obtain card status, it suggests we can no
* longer communicate with the card.
* - Check the card state. If the card received the cmd but there was a
* transient problem with the response, it might still be in a data transfer
* mode. Try to send it a stop command. If this fails, we can't recover.
* - If the r/w cmd failed due to a response CRC error, it was probably
* transient, so retry the cmd.
* - If the r/w cmd timed out, but we didn't get the r/w cmd status, retry.
* - If the r/w cmd timed out, and the r/w cmd failed due to CRC error or
* illegal cmd, retry.
* Otherwise we don't understand what happened, so abort.
*/
static int mmc_blk_cmd_recovery(struct mmc_card *card, struct request *req,
struct mmc_blk_request *brq)
{
bool prev_cmd_status_valid = true;
u32 status, stop_status = 0;
int err, retry;
/*
* Try to get card status which indicates both the card state
* and why there was no response. If the first attempt fails,
* we can't be sure the returned status is for the r/w command.
*/
for (retry = 2; retry >= 0; retry--) {
err = get_card_status(card, &status, 0);
if (!err)
break;
prev_cmd_status_valid = false;
pr_err("%s: error %d sending status command, %sing\n",
req->rq_disk->disk_name, err, retry ? "retry" : "abort");
}
/* We couldn't get a response from the card. Give up. */
if (err)
return ERR_ABORT;
/*
* Check the current card state. If it is in some data transfer
* mode, tell it to stop (and hopefully transition back to TRAN.)
*/
if (R1_CURRENT_STATE(status) == R1_STATE_DATA ||
R1_CURRENT_STATE(status) == R1_STATE_RCV) {
err = send_stop(card, &stop_status);
if (err)
pr_err("%s: error %d sending stop command\n",
req->rq_disk->disk_name, err);
/*
* If the stop cmd also timed out, the card is probably
* not present, so abort. Other errors are bad news too.
*/
if (err)
return ERR_ABORT;
}
/* Check for set block count errors */
if (brq->sbc.error)
return mmc_blk_cmd_error(req, "SET_BLOCK_COUNT", brq->sbc.error,
prev_cmd_status_valid, status);
/* Check for r/w command errors */
if (brq->cmd.error)
return mmc_blk_cmd_error(req, "r/w cmd", brq->cmd.error,
prev_cmd_status_valid, status);
/* Now for stop errors. These aren't fatal to the transfer. */
pr_err("%s: error %d sending stop command, original cmd response %#x, card status %#x\n",
req->rq_disk->disk_name, brq->stop.error,
brq->cmd.resp[0], status);
/*
* Subsitute in our own stop status as this will give the error
* state which happened during the execution of the r/w command.
*/
if (stop_status) {
brq->stop.resp[0] = stop_status;
brq->stop.error = 0;
}
return ERR_CONTINUE;
}
static int mmc_blk_issue_discard_rq(struct mmc_queue *mq, struct request *req)
{
struct mmc_blk_data *md = mq->data;
struct mmc_card *card = md->queue.card;
unsigned int from, nr, arg;
int err = 0;
if (!mmc_can_erase(card)) {
err = -EOPNOTSUPP;
goto out;
}
from = blk_rq_pos(req);
nr = blk_rq_sectors(req);
if (mmc_can_trim(card))
arg = MMC_TRIM_ARG;
else
arg = MMC_ERASE_ARG;
if (card->quirks & MMC_QUIRK_INAND_CMD38) {
err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
INAND_CMD38_ARG_EXT_CSD,
arg == MMC_TRIM_ARG ?
INAND_CMD38_ARG_TRIM :
INAND_CMD38_ARG_ERASE,
0);
if (err)
goto out;
}
err = mmc_erase(card, from, nr, arg);
out:
spin_lock_irq(&md->lock);
__blk_end_request(req, err, blk_rq_bytes(req));
spin_unlock_irq(&md->lock);
return err ? 0 : 1;
}
static int mmc_blk_issue_secdiscard_rq(struct mmc_queue *mq,
struct request *req)
{
struct mmc_blk_data *md = mq->data;
struct mmc_card *card = md->queue.card;
unsigned int from, nr, arg;
int err = 0;
if (!mmc_can_secure_erase_trim(card)) {
err = -EOPNOTSUPP;
goto out;
}
from = blk_rq_pos(req);
nr = blk_rq_sectors(req);
if (mmc_can_trim(card) && !mmc_erase_group_aligned(card, from, nr))
arg = MMC_SECURE_TRIM1_ARG;
else
arg = MMC_SECURE_ERASE_ARG;
if (card->quirks & MMC_QUIRK_INAND_CMD38) {
err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
INAND_CMD38_ARG_EXT_CSD,
arg == MMC_SECURE_TRIM1_ARG ?
INAND_CMD38_ARG_SECTRIM1 :
INAND_CMD38_ARG_SECERASE,
0);
if (err)
goto out;
}
err = mmc_erase(card, from, nr, arg);
if (!err && arg == MMC_SECURE_TRIM1_ARG) {
if (card->quirks & MMC_QUIRK_INAND_CMD38) {
err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
INAND_CMD38_ARG_EXT_CSD,
INAND_CMD38_ARG_SECTRIM2,
0);
if (err)
goto out;
}
err = mmc_erase(card, from, nr, MMC_SECURE_TRIM2_ARG);
}
out:
spin_lock_irq(&md->lock);
__blk_end_request(req, err, blk_rq_bytes(req));
spin_unlock_irq(&md->lock);
return err ? 0 : 1;
}
static int mmc_blk_issue_flush(struct mmc_queue *mq, struct request *req)
{
struct mmc_blk_data *md = mq->data;
/*
* No-op, only service this because we need REQ_FUA for reliable
* writes.
*/
spin_lock_irq(&md->lock);
__blk_end_request_all(req, 0);
spin_unlock_irq(&md->lock);
return 1;
}
/*
* Reformat current write as a reliable write, supporting
* both legacy and the enhanced reliable write MMC cards.
* In each transfer we'll handle only as much as a single
* reliable write can handle, thus finish the request in
* partial completions.
*/
static inline void mmc_apply_rel_rw(struct mmc_blk_request *brq,
struct mmc_card *card,
struct request *req)
{
if (!(card->ext_csd.rel_param & EXT_CSD_WR_REL_PARAM_EN)) {
/* Legacy mode imposes restrictions on transfers. */
if (!IS_ALIGNED(brq->cmd.arg, card->ext_csd.rel_sectors))
brq->data.blocks = 1;
if (brq->data.blocks > card->ext_csd.rel_sectors)
brq->data.blocks = card->ext_csd.rel_sectors;
else if (brq->data.blocks < card->ext_csd.rel_sectors)
brq->data.blocks = 1;
}
}
#define CMD_ERRORS \
(R1_OUT_OF_RANGE | /* Command argument out of range */ \
R1_ADDRESS_ERROR | /* Misaligned address */ \
R1_BLOCK_LEN_ERROR | /* Transferred block length incorrect */\
R1_WP_VIOLATION | /* Tried to write to protected block */ \
R1_CC_ERROR | /* Card controller error */ \
R1_ERROR) /* General/unknown error */
static int mmc_blk_err_check(struct mmc_card *card,
struct mmc_async_req *areq)
{
enum mmc_blk_status ret = MMC_BLK_SUCCESS;
struct mmc_queue_req *mq_mrq = container_of(areq, struct mmc_queue_req,
mmc_active);
struct mmc_blk_request *brq = &mq_mrq->brq;
struct request *req = mq_mrq->req;
/*
* sbc.error indicates a problem with the set block count
* command. No data will have been transferred.
*
* cmd.error indicates a problem with the r/w command. No
* data will have been transferred.
*
* stop.error indicates a problem with the stop command. Data
* may have been transferred, or may still be transferring.
*/
if (brq->sbc.error || brq->cmd.error || brq->stop.error) {
switch (mmc_blk_cmd_recovery(card, req, brq)) {
case ERR_RETRY:
return MMC_BLK_RETRY;
case ERR_ABORT:
return MMC_BLK_ABORT;
case ERR_CONTINUE:
break;
}
}
/*
* Check for errors relating to the execution of the
* initial command - such as address errors. No data
* has been transferred.
*/
if (brq->cmd.resp[0] & CMD_ERRORS) {
pr_err("%s: r/w command failed, status = %#x\n",
req->rq_disk->disk_name, brq->cmd.resp[0]);
return MMC_BLK_ABORT;
}
/*
* Everything else is either success, or a data error of some
* kind. If it was a write, we may have transitioned to
* program mode, which we have to wait for it to complete.
*/
if (!mmc_host_is_spi(card->host) && rq_data_dir(req) != READ) {
u32 status;
do {
int err = get_card_status(card, &status, 5);
if (err) {
printk(KERN_ERR "%s: error %d requesting status\n",
req->rq_disk->disk_name, err);
return MMC_BLK_CMD_ERR;
}
/*
* Some cards mishandle the status bits,
* so make sure to check both the busy
* indication and the card state.
*/
} while (!(status & R1_READY_FOR_DATA) ||
(R1_CURRENT_STATE(status) == R1_STATE_PRG));
}
if (brq->data.error) {
pr_err("%s: error %d transferring data, sector %u, nr %u, cmd response %#x, card status %#x\n",
req->rq_disk->disk_name, brq->data.error,
(unsigned)blk_rq_pos(req),
(unsigned)blk_rq_sectors(req),
brq->cmd.resp[0], brq->stop.resp[0]);
if (rq_data_dir(req) == READ) {
if (brq->data.blocks > 1) {
/* Redo read one sector at a time */
pr_warning("%s: retrying using single block read\n",
req->rq_disk->disk_name);
return MMC_BLK_RETRY_SINGLE;
}
return MMC_BLK_DATA_ERR;
} else {
return MMC_BLK_CMD_ERR;
}
}
if (ret == MMC_BLK_SUCCESS &&
blk_rq_bytes(req) != brq->data.bytes_xfered)
ret = MMC_BLK_PARTIAL;
return ret;
}
static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq,
struct mmc_card *card,
int disable_multi,
struct mmc_queue *mq)
{
u32 readcmd, writecmd;
struct mmc_blk_request *brq = &mqrq->brq;
struct request *req = mqrq->req;
struct mmc_blk_data *md = mq->data;
/*
* Reliable writes are used to implement Forced Unit Access and
* REQ_META accesses, and are supported only on MMCs.
*
* XXX: this really needs a good explanation of why REQ_META
* is treated special.
*/
bool do_rel_wr = ((req->cmd_flags & REQ_FUA) ||
(req->cmd_flags & REQ_META)) &&
(rq_data_dir(req) == WRITE) &&
(md->flags & MMC_BLK_REL_WR);
memset(brq, 0, sizeof(struct mmc_blk_request));
brq->mrq.cmd = &brq->cmd;
brq->mrq.data = &brq->data;
brq->cmd.arg = blk_rq_pos(req);
if (!mmc_card_blockaddr(card))
brq->cmd.arg <<= 9;
brq->cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
brq->data.blksz = 512;
brq->stop.opcode = MMC_STOP_TRANSMISSION;
brq->stop.arg = 0;
brq->stop.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
brq->data.blocks = blk_rq_sectors(req);
/*
* The block layer doesn't support all sector count
* restrictions, so we need to be prepared for too big
* requests.
*/
if (brq->data.blocks > card->host->max_blk_count)
brq->data.blocks = card->host->max_blk_count;
/*
* After a read error, we redo the request one sector at a time
* in order to accurately determine which sectors can be read
* successfully.
*/
if (disable_multi && brq->data.blocks > 1)
brq->data.blocks = 1;
if (brq->data.blocks > 1 || do_rel_wr) {
/* SPI multiblock writes terminate using a special
* token, not a STOP_TRANSMISSION request.
*/
if (!mmc_host_is_spi(card->host) ||
rq_data_dir(req) == READ)
brq->mrq.stop = &brq->stop;
readcmd = MMC_READ_MULTIPLE_BLOCK;
writecmd = MMC_WRITE_MULTIPLE_BLOCK;
} else {
brq->mrq.stop = NULL;
readcmd = MMC_READ_SINGLE_BLOCK;
writecmd = MMC_WRITE_BLOCK;
}
if (rq_data_dir(req) == READ) {
brq->cmd.opcode = readcmd;
brq->data.flags |= MMC_DATA_READ;
} else {
brq->cmd.opcode = writecmd;
brq->data.flags |= MMC_DATA_WRITE;
}
if (do_rel_wr)
mmc_apply_rel_rw(brq, card, req);
/*
* Pre-defined multi-block transfers are preferable to
* open ended-ones (and necessary for reliable writes).
* However, it is not sufficient to just send CMD23,
* and avoid the final CMD12, as on an error condition
* CMD12 (stop) needs to be sent anyway. This, coupled
* with Auto-CMD23 enhancements provided by some
* hosts, means that the complexity of dealing
* with this is best left to the host. If CMD23 is
* supported by card and host, we'll fill sbc in and let
* the host deal with handling it correctly. This means
* that for hosts that don't expose MMC_CAP_CMD23, no
* change of behavior will be observed.
*
* N.B: Some MMC cards experience perf degradation.
* We'll avoid using CMD23-bounded multiblock writes for
* these, while retaining features like reliable writes.
*/
if ((md->flags & MMC_BLK_CMD23) &&
mmc_op_multi(brq->cmd.opcode) &&
(do_rel_wr || !(card->quirks & MMC_QUIRK_BLK_NO_CMD23))) {
brq->sbc.opcode = MMC_SET_BLOCK_COUNT;
brq->sbc.arg = brq->data.blocks |
(do_rel_wr ? (1 << 31) : 0);
brq->sbc.flags = MMC_RSP_R1 | MMC_CMD_AC;
brq->mrq.sbc = &brq->sbc;
}
mmc_set_data_timeout(&brq->data, card);
brq->data.sg = mqrq->sg;
brq->data.sg_len = mmc_queue_map_sg(mq, mqrq);
/*
* Adjust the sg list so it is the same size as the
* request.
*/
if (brq->data.blocks != blk_rq_sectors(req)) {
int i, data_size = brq->data.blocks << 9;
struct scatterlist *sg;
for_each_sg(brq->data.sg, sg, brq->data.sg_len, i) {
data_size -= sg->length;
if (data_size <= 0) {
sg->length += data_size;
i++;
break;
}
}
brq->data.sg_len = i;
}
mqrq->mmc_active.mrq = &brq->mrq;
mqrq->mmc_active.err_check = mmc_blk_err_check;
mmc_queue_bounce_pre(mqrq);
}
static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
{
struct mmc_blk_data *md = mq->data;
struct mmc_card *card = md->queue.card;
struct mmc_blk_request *brq = &mq->mqrq_cur->brq;
int ret = 1, disable_multi = 0, retry = 0;
enum mmc_blk_status status;
struct mmc_queue_req *mq_rq;
struct request *req;
struct mmc_async_req *areq;
if (!rqc && !mq->mqrq_prev->req)
return 0;
do {
if (rqc) {
mmc_blk_rw_rq_prep(mq->mqrq_cur, card, 0, mq);
areq = &mq->mqrq_cur->mmc_active;
} else
areq = NULL;
areq = mmc_start_req(card->host, areq, (int *) &status);
if (!areq)
return 0;
mq_rq = container_of(areq, struct mmc_queue_req, mmc_active);
brq = &mq_rq->brq;
req = mq_rq->req;
mmc_queue_bounce_post(mq_rq);
switch (status) {
case MMC_BLK_SUCCESS:
case MMC_BLK_PARTIAL:
/*
* A block was successfully transferred.
*/
spin_lock_irq(&md->lock);
ret = __blk_end_request(req, 0,
brq->data.bytes_xfered);
spin_unlock_irq(&md->lock);
if (status == MMC_BLK_SUCCESS && ret) {
/*
* The blk_end_request has returned non zero
* even though all data is transfered and no
* erros returned by host.
* If this happen it's a bug.
*/
printk(KERN_ERR "%s BUG rq_tot %d d_xfer %d\n",
__func__, blk_rq_bytes(req),
brq->data.bytes_xfered);
rqc = NULL;
goto cmd_abort;
}
break;
case MMC_BLK_CMD_ERR:
goto cmd_err;
case MMC_BLK_RETRY_SINGLE:
disable_multi = 1;
break;
case MMC_BLK_RETRY:
if (retry++ < 5)
break;
case MMC_BLK_ABORT:
goto cmd_abort;
case MMC_BLK_DATA_ERR:
/*
* After an error, we redo I/O one sector at a
* time, so we only reach here after trying to
* read a single sector.
*/
spin_lock_irq(&md->lock);
ret = __blk_end_request(req, -EIO,
brq->data.blksz);
spin_unlock_irq(&md->lock);
if (!ret)
goto start_new_req;
break;
}
if (ret) {
/*
* In case of a none complete request
* prepare it again and resend.
*/
mmc_blk_rw_rq_prep(mq_rq, card, disable_multi, mq);
mmc_start_req(card->host, &mq_rq->mmc_active, NULL);
}
} while (ret);
return 1;
cmd_err:
/*
* If this is an SD card and we're writing, we can first
* mark the known good sectors as ok.
*
* If the card is not SD, we can still ok written sectors
* as reported by the controller (which might be less than
* the real number of written sectors, but never more).
*/
if (mmc_card_sd(card)) {
u32 blocks;
blocks = mmc_sd_num_wr_blocks(card);
if (blocks != (u32)-1) {
spin_lock_irq(&md->lock);
ret = __blk_end_request(req, 0, blocks << 9);
spin_unlock_irq(&md->lock);
}
} else {
spin_lock_irq(&md->lock);
ret = __blk_end_request(req, 0, brq->data.bytes_xfered);
spin_unlock_irq(&md->lock);
}
cmd_abort:
spin_lock_irq(&md->lock);
while (ret)
ret = __blk_end_request(req, -EIO, blk_rq_cur_bytes(req));
spin_unlock_irq(&md->lock);
start_new_req:
if (rqc) {
mmc_blk_rw_rq_prep(mq->mqrq_cur, card, 0, mq);
mmc_start_req(card->host, &mq->mqrq_cur->mmc_active, NULL);
}
return 0;
}
static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
{
int ret;
struct mmc_blk_data *md = mq->data;
struct mmc_card *card = md->queue.card;
if (req && !mq->mqrq_prev->req)
/* claim host only for the first request */
mmc_claim_host(card->host);
ret = mmc_blk_part_switch(card, md);
if (ret) {
ret = 0;
goto out;
}
if (req && req->cmd_flags & REQ_DISCARD) {
/* complete ongoing async transfer before issuing discard */
if (card->host->areq)
mmc_blk_issue_rw_rq(mq, NULL);
if (req->cmd_flags & REQ_SECURE)
ret = mmc_blk_issue_secdiscard_rq(mq, req);
else
ret = mmc_blk_issue_discard_rq(mq, req);
} else if (req && req->cmd_flags & REQ_FLUSH) {
/* complete ongoing async transfer before issuing flush */
if (card->host->areq)
mmc_blk_issue_rw_rq(mq, NULL);
ret = mmc_blk_issue_flush(mq, req);
} else {
ret = mmc_blk_issue_rw_rq(mq, req);
}
out:
if (!req)
/* release host only when there are no more requests */
mmc_release_host(card->host);
return ret;
}
static inline int mmc_blk_readonly(struct mmc_card *card)
{
return mmc_card_readonly(card) ||
!(card->csd.cmdclass & CCC_BLOCK_WRITE);
}
static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
struct device *parent,
sector_t size,
bool default_ro,
const char *subname)
{
struct mmc_blk_data *md;
int devidx, ret;
devidx = find_first_zero_bit(dev_use, max_devices);
if (devidx >= max_devices)
return ERR_PTR(-ENOSPC);
__set_bit(devidx, dev_use);
md = kzalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
if (!md) {
ret = -ENOMEM;
goto out;
}
/*
* !subname implies we are creating main mmc_blk_data that will be
* associated with mmc_card with mmc_set_drvdata. Due to device
* partitions, devidx will not coincide with a per-physical card
* index anymore so we keep track of a name index.
*/
if (!subname) {
md->name_idx = find_first_zero_bit(name_use, max_devices);
__set_bit(md->name_idx, name_use);
}
else
md->name_idx = ((struct mmc_blk_data *)
dev_to_disk(parent)->private_data)->name_idx;
/*
* Set the read-only status based on the supported commands
* and the write protect switch.
*/
md->read_only = mmc_blk_readonly(card);
md->disk = alloc_disk(perdev_minors);
if (md->disk == NULL) {
ret = -ENOMEM;
goto err_kfree;
}
spin_lock_init(&md->lock);
INIT_LIST_HEAD(&md->part);
md->usage = 1;
ret = mmc_init_queue(&md->queue, card, &md->lock, subname);
if (ret)
goto err_putdisk;
md->queue.issue_fn = mmc_blk_issue_rq;
md->queue.data = md;
md->disk->major = MMC_BLOCK_MAJOR;
md->disk->first_minor = devidx * perdev_minors;
md->disk->fops = &mmc_bdops;
md->disk->private_data = md;
md->disk->queue = md->queue.queue;
md->disk->driverfs_dev = parent;
set_disk_ro(md->disk, md->read_only || default_ro);
/*
* As discussed on lkml, GENHD_FL_REMOVABLE should:
*
* - be set for removable media with permanent block devices
* - be unset for removable block devices with permanent media
*
* Since MMC block devices clearly fall under the second
* case, we do not set GENHD_FL_REMOVABLE. Userspace
* should use the block device creation/destruction hotplug
* messages to tell when the card is present.
*/
snprintf(md->disk->disk_name, sizeof(md->disk->disk_name),
"mmcblk%d%s", md->name_idx, subname ? subname : "");
blk_queue_logical_block_size(md->queue.queue, 512);
set_capacity(md->disk, size);
if (mmc_host_cmd23(card->host)) {
if (mmc_card_mmc(card) ||
(mmc_card_sd(card) &&
card->scr.cmds & SD_SCR_CMD23_SUPPORT))
md->flags |= MMC_BLK_CMD23;
}
if (mmc_card_mmc(card) &&
md->flags & MMC_BLK_CMD23 &&
((card->ext_csd.rel_param & EXT_CSD_WR_REL_PARAM_EN) ||
card->ext_csd.rel_sectors)) {
md->flags |= MMC_BLK_REL_WR;
blk_queue_flush(md->queue.queue, REQ_FLUSH | REQ_FUA);
}
return md;
err_putdisk:
put_disk(md->disk);
err_kfree:
kfree(md);
out:
return ERR_PTR(ret);
}
static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
{
sector_t size;
struct mmc_blk_data *md;
if (!mmc_card_sd(card) && mmc_card_blockaddr(card)) {
/*
* The EXT_CSD sector count is in number or 512 byte
* sectors.
*/
size = card->ext_csd.sectors;
} else {
/*
* The CSD capacity field is in units of read_blkbits.
* set_capacity takes units of 512 bytes.
*/
size = card->csd.capacity << (card->csd.read_blkbits - 9);
}
md = mmc_blk_alloc_req(card, &card->dev, size, false, NULL);
return md;
}
static int mmc_blk_alloc_part(struct mmc_card *card,
struct mmc_blk_data *md,
unsigned int part_type,
sector_t size,
bool default_ro,
const char *subname)
{
char cap_str[10];
struct mmc_blk_data *part_md;
part_md = mmc_blk_alloc_req(card, disk_to_dev(md->disk), size, default_ro,
subname);
if (IS_ERR(part_md))
return PTR_ERR(part_md);
part_md->part_type = part_type;
list_add(&part_md->part, &md->part);
string_get_size((u64)get_capacity(part_md->disk) << 9, STRING_UNITS_2,
cap_str, sizeof(cap_str));
printk(KERN_INFO "%s: %s %s partition %u %s\n",
part_md->disk->disk_name, mmc_card_id(card),
mmc_card_name(card), part_md->part_type, cap_str);
return 0;
}
static int mmc_blk_alloc_parts(struct mmc_card *card, struct mmc_blk_data *md)
{
int ret = 0;
if (!mmc_card_mmc(card))
return 0;
if (card->ext_csd.boot_size) {
ret = mmc_blk_alloc_part(card, md, EXT_CSD_PART_CONFIG_ACC_BOOT0,
card->ext_csd.boot_size >> 9,
true,
"boot0");
if (ret)
return ret;
ret = mmc_blk_alloc_part(card, md, EXT_CSD_PART_CONFIG_ACC_BOOT1,
card->ext_csd.boot_size >> 9,
true,
"boot1");
if (ret)
return ret;
}
return ret;
}
static int
mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
{
int err;
mmc_claim_host(card->host);
err = mmc_set_blocklen(card, 512);
mmc_release_host(card->host);
if (err) {
printk(KERN_ERR "%s: unable to set block size to 512: %d\n",
md->disk->disk_name, err);
return -EINVAL;
}
return 0;
}
static void mmc_blk_remove_req(struct mmc_blk_data *md)
{
if (md) {
if (md->disk->flags & GENHD_FL_UP) {
device_remove_file(disk_to_dev(md->disk), &md->force_ro);
/* Stop new requests from getting into the queue */
del_gendisk(md->disk);
}
/* Then flush out any already in there */
mmc_cleanup_queue(&md->queue);
mmc_blk_put(md);
}
}
static void mmc_blk_remove_parts(struct mmc_card *card,
struct mmc_blk_data *md)
{
struct list_head *pos, *q;
struct mmc_blk_data *part_md;
__clear_bit(md->name_idx, name_use);
list_for_each_safe(pos, q, &md->part) {
part_md = list_entry(pos, struct mmc_blk_data, part);
list_del(pos);
mmc_blk_remove_req(part_md);
}
}
static int mmc_add_disk(struct mmc_blk_data *md)
{
int ret;
add_disk(md->disk);
md->force_ro.show = force_ro_show;
md->force_ro.store = force_ro_store;
sysfs_attr_init(&md->force_ro.attr);
md->force_ro.attr.name = "force_ro";
md->force_ro.attr.mode = S_IRUGO | S_IWUSR;
ret = device_create_file(disk_to_dev(md->disk), &md->force_ro);
if (ret)
del_gendisk(md->disk);
return ret;
}
static const struct mmc_fixup blk_fixups[] =
{
MMC_FIXUP("SEM02G", 0x2, 0x100, add_quirk, MMC_QUIRK_INAND_CMD38),
MMC_FIXUP("SEM04G", 0x2, 0x100, add_quirk, MMC_QUIRK_INAND_CMD38),
MMC_FIXUP("SEM08G", 0x2, 0x100, add_quirk, MMC_QUIRK_INAND_CMD38),
MMC_FIXUP("SEM16G", 0x2, 0x100, add_quirk, MMC_QUIRK_INAND_CMD38),
MMC_FIXUP("SEM32G", 0x2, 0x100, add_quirk, MMC_QUIRK_INAND_CMD38),
/*
* Some MMC cards experience performance degradation with CMD23
* instead of CMD12-bounded multiblock transfers. For now we'll
* black list what's bad...
* - Certain Toshiba cards.
*
* N.B. This doesn't affect SD cards.
*/
MMC_FIXUP("MMC08G", 0x11, CID_OEMID_ANY, add_quirk_mmc,
MMC_QUIRK_BLK_NO_CMD23),
MMC_FIXUP("MMC16G", 0x11, CID_OEMID_ANY, add_quirk_mmc,
MMC_QUIRK_BLK_NO_CMD23),
MMC_FIXUP("MMC32G", 0x11, CID_OEMID_ANY, add_quirk_mmc,
MMC_QUIRK_BLK_NO_CMD23),
END_FIXUP
};
static int mmc_blk_probe(struct mmc_card *card)
{
struct mmc_blk_data *md, *part_md;
int err;
char cap_str[10];
/*
* Check that the card supports the command class(es) we need.
*/
if (!(card->csd.cmdclass & CCC_BLOCK_READ))
return -ENODEV;
md = mmc_blk_alloc(card);
if (IS_ERR(md))
return PTR_ERR(md);
err = mmc_blk_set_blksize(md, card);
if (err)
goto out;
string_get_size((u64)get_capacity(md->disk) << 9, STRING_UNITS_2,
cap_str, sizeof(cap_str));
printk(KERN_INFO "%s: %s %s %s %s\n",
md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
cap_str, md->read_only ? "(ro)" : "");
if (mmc_blk_alloc_parts(card, md))
goto out;
mmc_set_drvdata(card, md);
mmc_fixup_device(card, blk_fixups);
if (mmc_add_disk(md))
goto out;
list_for_each_entry(part_md, &md->part, part) {
if (mmc_add_disk(part_md))
goto out;
}
return 0;
out:
mmc_blk_remove_parts(card, md);
mmc_blk_remove_req(md);
return err;
}
static void mmc_blk_remove(struct mmc_card *card)
{
struct mmc_blk_data *md = mmc_get_drvdata(card);
mmc_blk_remove_parts(card, md);
mmc_claim_host(card->host);
mmc_blk_part_switch(card, md);
mmc_release_host(card->host);
mmc_blk_remove_req(md);
mmc_set_drvdata(card, NULL);
}
#ifdef CONFIG_PM
static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
{
struct mmc_blk_data *part_md;
struct mmc_blk_data *md = mmc_get_drvdata(card);
if (md) {
mmc_queue_suspend(&md->queue);
list_for_each_entry(part_md, &md->part, part) {
mmc_queue_suspend(&part_md->queue);
}
}
return 0;
}
static int mmc_blk_resume(struct mmc_card *card)
{
struct mmc_blk_data *part_md;
struct mmc_blk_data *md = mmc_get_drvdata(card);
if (md) {
mmc_blk_set_blksize(md, card);
/*
* Resume involves the card going into idle state,
* so current partition is always the main one.
*/
md->part_curr = md->part_type;
mmc_queue_resume(&md->queue);
list_for_each_entry(part_md, &md->part, part) {
mmc_queue_resume(&part_md->queue);
}
}
return 0;
}
#else
#define mmc_blk_suspend NULL
#define mmc_blk_resume NULL
#endif
static struct mmc_driver mmc_driver = {
.drv = {
.name = "mmcblk",
},
.probe = mmc_blk_probe,
.remove = mmc_blk_remove,
.suspend = mmc_blk_suspend,
.resume = mmc_blk_resume,
};
static int __init mmc_blk_init(void)
{
int res;
if (perdev_minors != CONFIG_MMC_BLOCK_MINORS)
pr_info("mmcblk: using %d minors per device\n", perdev_minors);
max_devices = 256 / perdev_minors;
res = register_blkdev(MMC_BLOCK_MAJOR, "mmc");
if (res)
goto out;
res = mmc_register_driver(&mmc_driver);
if (res)
goto out2;
return 0;
out2:
unregister_blkdev(MMC_BLOCK_MAJOR, "mmc");
out:
return res;
}
static void __exit mmc_blk_exit(void)
{
mmc_unregister_driver(&mmc_driver);
unregister_blkdev(MMC_BLOCK_MAJOR, "mmc");
}
module_init(mmc_blk_init);
module_exit(mmc_blk_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");