Gitiles
Code Review Sign In
gerrit-public.fairphone.software / kernel / msm-4.19 / 8f90409f91e338fc8b026bffafe7a3877d1a5ac7 / . / drivers / mmc / core / block.c
blob: 80d1ec693d2d7d798b1f3315b3c205b529f9a382 [file] [log] [blame]
/*
* 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/pm_runtime.h>
#include <linux/idr.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 <linux/uaccess.h>
#include "queue.h"
#include "block.h"
#include "core.h"
#include "card.h"
#include "host.h"
#include "bus.h"
#include "mmc_ops.h"
#include "quirks.h"
#include "sd_ops.h"
MODULE_ALIAS("mmc:block");
#ifdef MODULE_PARAM_PREFIX
#undef MODULE_PARAM_PREFIX
#endif
#define MODULE_PARAM_PREFIX "mmcblk."
#define MMC_BLK_TIMEOUT_MS (10 * 60 * 1000) /* 10 minute timeout */
#define MMC_SANITIZE_REQ_TIMEOUT 240000
#define MMC_EXTRACT_INDEX_FROM_ARG(x) ((x & 0x00FF0000) >> 16)
#define mmc_req_rel_wr(req) ((req->cmd_flags & REQ_FUA) && \
(rq_data_dir(req) == WRITE))
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 (1 << 20) / number of minors per device. It is also
* limited by the MAX_DEVICES below.
*/
static int max_devices;
#define MAX_DEVICES 256
static DEFINE_IDA(mmc_blk_ida);
/*
* There is one mmc_blk_data per slot.
*/
struct mmc_blk_data {
spinlock_t lock;
struct device *parent;
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 reset_done;
#define MMC_BLK_READ BIT(0)
#define MMC_BLK_WRITE BIT(1)
#define MMC_BLK_DISCARD BIT(2)
#define MMC_BLK_SECDISCARD BIT(3)
/*
* Only set in main mmc_blk_data associated
* with mmc_card with dev_set_drvdata, and keeps
* track of the current selected device partition.
*/
unsigned int part_curr;
struct device_attribute force_ro;
struct device_attribute power_ro_lock;
int area_type;
};
static DEFINE_MUTEX(open_lock);
module_param(perdev_minors, int, 0444);
MODULE_PARM_DESC(perdev_minors, "Minors numbers to allocate per device");
static inline int mmc_blk_part_switch(struct mmc_card *card,
struct mmc_blk_data *md);
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 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);
ida_simple_remove(&mmc_blk_ida, devidx);
put_disk(md->disk);
kfree(md);
}
mutex_unlock(&open_lock);
}
static ssize_t power_ro_lock_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
int ret;
struct mmc_blk_data *md = mmc_blk_get(dev_to_disk(dev));
struct mmc_card *card = md->queue.card;
int locked = 0;
if (card->ext_csd.boot_ro_lock & EXT_CSD_BOOT_WP_B_PERM_WP_EN)
locked = 2;
else if (card->ext_csd.boot_ro_lock & EXT_CSD_BOOT_WP_B_PWR_WP_EN)
locked = 1;
ret = snprintf(buf, PAGE_SIZE, "%d\n", locked);
mmc_blk_put(md);
return ret;
}
static ssize_t power_ro_lock_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
int ret;
struct mmc_blk_data *md, *part_md;
struct mmc_card *card;
struct mmc_queue *mq;
struct request *req;
unsigned long set;
if (kstrtoul(buf, 0, &set))
return -EINVAL;
if (set != 1)
return count;
md = mmc_blk_get(dev_to_disk(dev));
mq = &md->queue;
card = md->queue.card;
/* Dispatch locking to the block layer */
req = blk_get_request(mq->queue, REQ_OP_DRV_OUT, __GFP_RECLAIM);
req_to_mmc_queue_req(req)->drv_op = MMC_DRV_OP_BOOT_WP;
blk_execute_rq(mq->queue, NULL, req, 0);
ret = req_to_mmc_queue_req(req)->drv_op_result;
if (!ret) {
pr_info("%s: Locking boot partition ro until next power on\n",
md->disk->disk_name);
set_disk_ro(md->disk, 1);
list_for_each_entry(part_md, &md->part, part)
if (part_md->area_type == MMC_BLK_DATA_AREA_BOOT) {
pr_info("%s: Locking boot partition ro until next power on\n", part_md->disk->disk_name);
set_disk_ro(part_md->disk, 1);
}
}
mmc_blk_put(md);
return count;
}
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\n",
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 void 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);
}
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 = kmalloc(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;
}
if (!idata->buf_bytes) {
idata->buf = NULL;
return idata;
}
idata->buf = kmalloc(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_copy_to_user(struct mmc_ioc_cmd __user *ic_ptr,
struct mmc_blk_ioc_data *idata)
{
struct mmc_ioc_cmd *ic = &idata->ic;
if (copy_to_user(&(ic_ptr->response), ic->response,
sizeof(ic->response)))
return -EFAULT;
if (!idata->ic.write_flag) {
if (copy_to_user((void __user *)(unsigned long)ic->data_ptr,
idata->buf, idata->buf_bytes))
return -EFAULT;
}
return 0;
}
static int ioctl_rpmb_card_status_poll(struct mmc_card *card, u32 *status,
u32 retries_max)
{
int err;
u32 retry_count = 0;
if (!status || !retries_max)
return -EINVAL;
do {
err = __mmc_send_status(card, status, 5);
if (err)
break;
if (!R1_STATUS(*status) &&
(R1_CURRENT_STATE(*status) != R1_STATE_PRG))
break; /* RPMB programming operation complete */
/*
* Rechedule to give the MMC device a chance to continue
* processing the previous command without being polled too
* frequently.
*/
usleep_range(1000, 5000);
} while (++retry_count < retries_max);
if (retry_count == retries_max)
err = -EPERM;
return err;
}
static int ioctl_do_sanitize(struct mmc_card *card)
{
int err;
if (!mmc_can_sanitize(card)) {
pr_warn("%s: %s - SANITIZE is not supported\n",
mmc_hostname(card->host), __func__);
err = -EOPNOTSUPP;
goto out;
}
pr_debug("%s: %s - SANITIZE IN PROGRESS...\n",
mmc_hostname(card->host), __func__);
err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
EXT_CSD_SANITIZE_START, 1,
MMC_SANITIZE_REQ_TIMEOUT);
if (err)
pr_err("%s: %s - EXT_CSD_SANITIZE_START failed. err=%d\n",
mmc_hostname(card->host), __func__, err);
pr_debug("%s: %s - SANITIZE COMPLETED\n", mmc_hostname(card->host),
__func__);
out:
return err;
}
static int __mmc_blk_ioctl_cmd(struct mmc_card *card, struct mmc_blk_data *md,
struct mmc_blk_ioc_data *idata)
{
struct mmc_command cmd = {};
struct mmc_data data = {};
struct mmc_request mrq = {};
struct scatterlist sg;
int err;
bool is_rpmb = false;
u32 status = 0;
if (!card || !md || !idata)
return -EINVAL;
if (md->area_type & MMC_BLK_DATA_AREA_RPMB)
is_rpmb = true;
cmd.opcode = idata->ic.opcode;
cmd.arg = idata->ic.arg;
cmd.flags = idata->ic.flags;
if (idata->buf_bytes) {
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;
/* 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;
}
mrq.data = &data;
}
mrq.cmd = &cmd;
err = mmc_blk_part_switch(card, md);
if (err)
return err;
if (idata->ic.is_acmd) {
err = mmc_app_cmd(card->host, card);
if (err)
return err;
}
if (is_rpmb) {
err = mmc_set_blockcount(card, data.blocks,
idata->ic.write_flag & (1 << 31));
if (err)
return err;
}
if ((MMC_EXTRACT_INDEX_FROM_ARG(cmd.arg) == EXT_CSD_SANITIZE_START) &&
(cmd.opcode == MMC_SWITCH)) {
err = ioctl_do_sanitize(card);
if (err)
pr_err("%s: ioctl_do_sanitize() failed. err = %d",
__func__, err);
return err;
}
mmc_wait_for_req(card->host, &mrq);
if (cmd.error) {
dev_err(mmc_dev(card->host), "%s: cmd error %d\n",
__func__, cmd.error);
return cmd.error;
}
if (data.error) {
dev_err(mmc_dev(card->host), "%s: data error %d\n",
__func__, data.error);
return data.error;
}
/*
* 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);
memcpy(&(idata->ic.response), cmd.resp, sizeof(cmd.resp));
if (is_rpmb) {
/*
* Ensure RPMB command has completed by polling CMD13
* "Send Status".
*/
err = ioctl_rpmb_card_status_poll(card, &status, 5);
if (err)
dev_err(mmc_dev(card->host),
"%s: Card Status=0x%08X, error %d\n",
__func__, status, err);
}
return 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_ioc_data *idatas[1];
struct mmc_blk_data *md;
struct mmc_queue *mq;
struct mmc_card *card;
int err = 0, ioc_err = 0;
struct request *req;
/*
* 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);
md = mmc_blk_get(bdev->bd_disk);
if (!md) {
err = -EINVAL;
goto cmd_err;
}
card = md->queue.card;
if (IS_ERR(card)) {
err = PTR_ERR(card);
goto cmd_done;
}
/*
* Dispatch the ioctl() into the block request queue.
*/
mq = &md->queue;
req = blk_get_request(mq->queue,
idata->ic.write_flag ? REQ_OP_DRV_OUT : REQ_OP_DRV_IN,
__GFP_RECLAIM);
idatas[0] = idata;
req_to_mmc_queue_req(req)->drv_op = MMC_DRV_OP_IOCTL;
req_to_mmc_queue_req(req)->idata = idatas;
req_to_mmc_queue_req(req)->ioc_count = 1;
blk_execute_rq(mq->queue, NULL, req, 0);
ioc_err = req_to_mmc_queue_req(req)->drv_op_result;
err = mmc_blk_ioctl_copy_to_user(ic_ptr, idata);
blk_put_request(req);
cmd_done:
mmc_blk_put(md);
cmd_err:
kfree(idata->buf);
kfree(idata);
return ioc_err ? ioc_err : err;
}
static int mmc_blk_ioctl_multi_cmd(struct block_device *bdev,
struct mmc_ioc_multi_cmd __user *user)
{
struct mmc_blk_ioc_data **idata = NULL;
struct mmc_ioc_cmd __user *cmds = user->cmds;
struct mmc_card *card;
struct mmc_blk_data *md;
struct mmc_queue *mq;
int i, err = 0, ioc_err = 0;
__u64 num_of_cmds;
struct request *req;
/*
* 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;
if (copy_from_user(&num_of_cmds, &user->num_of_cmds,
sizeof(num_of_cmds)))
return -EFAULT;
if (!num_of_cmds)
return 0;
if (num_of_cmds > MMC_IOC_MAX_CMDS)
return -EINVAL;
idata = kcalloc(num_of_cmds, sizeof(*idata), GFP_KERNEL);
if (!idata)
return -ENOMEM;
for (i = 0; i < num_of_cmds; i++) {
idata[i] = mmc_blk_ioctl_copy_from_user(&cmds[i]);
if (IS_ERR(idata[i])) {
err = PTR_ERR(idata[i]);
num_of_cmds = i;
goto cmd_err;
}
}
md = mmc_blk_get(bdev->bd_disk);
if (!md) {
err = -EINVAL;
goto cmd_err;
}
card = md->queue.card;
if (IS_ERR(card)) {
err = PTR_ERR(card);
goto cmd_done;
}
/*
* Dispatch the ioctl()s into the block request queue.
*/
mq = &md->queue;
req = blk_get_request(mq->queue,
idata[0]->ic.write_flag ? REQ_OP_DRV_OUT : REQ_OP_DRV_IN,
__GFP_RECLAIM);
req_to_mmc_queue_req(req)->drv_op = MMC_DRV_OP_IOCTL;
req_to_mmc_queue_req(req)->idata = idata;
req_to_mmc_queue_req(req)->ioc_count = num_of_cmds;
blk_execute_rq(mq->queue, NULL, req, 0);
ioc_err = req_to_mmc_queue_req(req)->drv_op_result;
/* copy to user if data and response */
for (i = 0; i < num_of_cmds && !err; i++)
err = mmc_blk_ioctl_copy_to_user(&cmds[i], idata[i]);
blk_put_request(req);
cmd_done:
mmc_blk_put(md);
cmd_err:
for (i = 0; i < num_of_cmds; i++) {
kfree(idata[i]->buf);
kfree(idata[i]);
}
kfree(idata);
return ioc_err ? ioc_err : err;
}
static int mmc_blk_ioctl(struct block_device *bdev, fmode_t mode,
unsigned int cmd, unsigned long arg)
{
switch (cmd) {
case MMC_IOC_CMD:
return mmc_blk_ioctl_cmd(bdev,
(struct mmc_ioc_cmd __user *)arg);
case MMC_IOC_MULTI_CMD:
return mmc_blk_ioctl_multi_cmd(bdev,
(struct mmc_ioc_multi_cmd __user *)arg);
default:
return -EINVAL;
}
}
#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 int mmc_blk_part_switch_pre(struct mmc_card *card,
unsigned int part_type)
{
int ret = 0;
if (part_type == EXT_CSD_PART_CONFIG_ACC_RPMB) {
if (card->ext_csd.cmdq_en) {
ret = mmc_cmdq_disable(card);
if (ret)
return ret;
}
mmc_retune_pause(card->host);
}
return ret;
}
static int mmc_blk_part_switch_post(struct mmc_card *card,
unsigned int part_type)
{
int ret = 0;
if (part_type == EXT_CSD_PART_CONFIG_ACC_RPMB) {
mmc_retune_unpause(card->host);
if (card->reenable_cmdq && !card->ext_csd.cmdq_en)
ret = mmc_cmdq_enable(card);
}
return ret;
}
static inline int mmc_blk_part_switch(struct mmc_card *card,
struct mmc_blk_data *md)
{
int ret = 0;
struct mmc_blk_data *main_md = dev_get_drvdata(&card->dev);
if (main_md->part_curr == md->part_type)
return 0;
if (mmc_card_mmc(card)) {
u8 part_config = card->ext_csd.part_config;
ret = mmc_blk_part_switch_pre(card, md->part_type);
if (ret)
return ret;
part_config &= ~EXT_CSD_PART_CONFIG_ACC_MASK;
part_config |= md->part_type;
ret = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
EXT_CSD_PART_CONFIG, part_config,
card->ext_csd.part_time);
if (ret) {
mmc_blk_part_switch_post(card, md->part_type);
return ret;
}
card->ext_csd.part_config = part_config;
ret = mmc_blk_part_switch_post(card, main_md->part_curr);
}
main_md->part_curr = md->part_type;
return ret;
}
static int mmc_sd_num_wr_blocks(struct mmc_card *card, u32 *written_blocks)
{
int err;
u32 result;
__be32 *blocks;
struct mmc_request mrq = {};
struct mmc_command cmd = {};
struct mmc_data data = {};
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 err;
if (!mmc_host_is_spi(card->host) && !(cmd.resp[0] & R1_APP_CMD))
return -EIO;
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.blksz = 4;
data.blocks = 1;
data.flags = MMC_DATA_READ;
data.sg = &sg;
data.sg_len = 1;
mmc_set_data_timeout(&data, card);
mrq.cmd = &cmd;
mrq.data = &data;
blocks = kmalloc(4, GFP_KERNEL);
if (!blocks)
return -ENOMEM;
sg_init_one(&sg, blocks, 4);
mmc_wait_for_req(card->host, &mrq);
result = ntohl(*blocks);
kfree(blocks);
if (cmd.error || data.error)
return -EIO;
*written_blocks = result;
return 0;
}
static int card_busy_detect(struct mmc_card *card, unsigned int timeout_ms,
bool hw_busy_detect, struct request *req, bool *gen_err)
{
unsigned long timeout = jiffies + msecs_to_jiffies(timeout_ms);
int err = 0;
u32 status;
do {
err = __mmc_send_status(card, &status, 5);
if (err) {
pr_err("%s: error %d requesting status\n",
req->rq_disk->disk_name, err);
return err;
}
if (status & R1_ERROR) {
pr_err("%s: %s: error sending status cmd, status %#x\n",
req->rq_disk->disk_name, __func__, status);
*gen_err = true;
}
/* We may rely on the host hw to handle busy detection.*/
if ((card->host->caps & MMC_CAP_WAIT_WHILE_BUSY) &&
hw_busy_detect)
break;
/*
* Timeout if the device never becomes ready for data and never
* leaves the program state.
*/
if (time_after(jiffies, timeout)) {
pr_err("%s: Card stuck in programming state! %s %s\n",
mmc_hostname(card->host),
req->rq_disk->disk_name, __func__);
return -ETIMEDOUT;
}
/*
* 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));
return err;
}
static int send_stop(struct mmc_card *card, unsigned int timeout_ms,
struct request *req, bool *gen_err, u32 *stop_status)
{
struct mmc_host *host = card->host;
struct mmc_command cmd = {};
int err;
bool use_r1b_resp = rq_data_dir(req) == WRITE;
/*
* Normally we use R1B responses for WRITE, but in cases where the host
* has specified a max_busy_timeout we need to validate it. A failure
* means we need to prevent the host from doing hw busy detection, which
* is done by converting to a R1 response instead.
*/
if (host->max_busy_timeout && (timeout_ms > host->max_busy_timeout))
use_r1b_resp = false;
cmd.opcode = MMC_STOP_TRANSMISSION;
if (use_r1b_resp) {
cmd.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
cmd.busy_timeout = timeout_ms;
} else {
cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
}
err = mmc_wait_for_cmd(host, &cmd, 5);
if (err)
return err;
*stop_status = cmd.resp[0];
/* No need to check card status in case of READ. */
if (rq_data_dir(req) == READ)
return 0;
if (!mmc_host_is_spi(host) &&
(*stop_status & R1_ERROR)) {
pr_err("%s: %s: general error sending stop command, resp %#x\n",
req->rq_disk->disk_name, __func__, *stop_status);
*gen_err = true;
}
return card_busy_detect(card, timeout_ms, use_r1b_resp, req, gen_err);
}
#define ERR_NOMEDIUM 3
#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) {
pr_err("%s: status not valid, retrying timeout\n",
req->rq_disk->disk_name);
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)) {
pr_err("%s: command error, retrying timeout\n",
req->rq_disk->disk_name);
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 *ecc_err, bool *gen_err)
{
bool prev_cmd_status_valid = true;
u32 status, stop_status = 0;
int err, retry;
if (mmc_card_removed(card))
return ERR_NOMEDIUM;
/*
* 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 = __mmc_send_status(card, &status, 0);
if (!err)
break;
/* Re-tune if needed */
mmc_retune_recheck(card->host);
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) {
/* Check if the card is removed */
if (mmc_detect_card_removed(card->host))
return ERR_NOMEDIUM;
return ERR_ABORT;
}
/* Flag ECC errors */
if ((status & R1_CARD_ECC_FAILED) ||
(brq->stop.resp[0] & R1_CARD_ECC_FAILED) ||
(brq->cmd.resp[0] & R1_CARD_ECC_FAILED))
*ecc_err = true;
/* Flag General errors */
if (!mmc_host_is_spi(card->host) && rq_data_dir(req) != READ)
if ((status & R1_ERROR) ||
(brq->stop.resp[0] & R1_ERROR)) {
pr_err("%s: %s: general error sending stop or status command, stop cmd response %#x, card status %#x\n",
req->rq_disk->disk_name, __func__,
brq->stop.resp[0], status);
*gen_err = true;
}
/*
* 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,
DIV_ROUND_UP(brq->data.timeout_ns, 1000000),
req, gen_err, &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.
*/
return ERR_ABORT;
}
if (stop_status & R1_CARD_ECC_FAILED)
*ecc_err = true;
}
/* 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);
/* Data errors */
if (!brq->stop.error)
return ERR_CONTINUE;
/* Now for stop errors. These aren't fatal to the transfer. */
pr_info("%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_reset(struct mmc_blk_data *md, struct mmc_host *host,
int type)
{
int err;
if (md->reset_done & type)
return -EEXIST;
md->reset_done |= type;
err = mmc_hw_reset(host);
/* Ensure we switch back to the correct partition */
if (err != -EOPNOTSUPP) {
struct mmc_blk_data *main_md =
dev_get_drvdata(&host->card->dev);
int part_err;
main_md->part_curr = main_md->part_type;
part_err = mmc_blk_part_switch(host->card, md);
if (part_err) {
/*
* We have failed to get back into the correct
* partition, so we need to abort the whole request.
*/
return -ENODEV;
}
}
return err;
}
static inline void mmc_blk_reset_success(struct mmc_blk_data *md, int type)
{
md->reset_done &= ~type;
}
int mmc_access_rpmb(struct mmc_queue *mq)
{
struct mmc_blk_data *md = mq->blkdata;
/*
* If this is a RPMB partition access, return ture
*/
if (md && md->part_type == EXT_CSD_PART_CONFIG_ACC_RPMB)
return true;
return false;
}
/*
* The non-block commands come back from the block layer after it queued it and
* processed it with all other requests and then they get issued in this
* function.
*/
static void mmc_blk_issue_drv_op(struct mmc_queue *mq, struct request *req)
{
struct mmc_queue_req *mq_rq;
struct mmc_card *card = mq->card;
struct mmc_blk_data *md = mq->blkdata;
int ret;
int i;
mq_rq = req_to_mmc_queue_req(req);
switch (mq_rq->drv_op) {
case MMC_DRV_OP_IOCTL:
for (i = 0, ret = 0; i < mq_rq->ioc_count; i++) {
ret = __mmc_blk_ioctl_cmd(card, md, mq_rq->idata[i]);
if (ret)
break;
}
/* Always switch back to main area after RPMB access */
if (md->area_type & MMC_BLK_DATA_AREA_RPMB)
mmc_blk_part_switch(card, dev_get_drvdata(&card->dev));
break;
case MMC_DRV_OP_BOOT_WP:
ret = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_BOOT_WP,
card->ext_csd.boot_ro_lock |
EXT_CSD_BOOT_WP_B_PWR_WP_EN,
card->ext_csd.part_time);
if (ret)
pr_err("%s: Locking boot partition ro until next power on failed: %d\n",
md->disk->disk_name, ret);
else
card->ext_csd.boot_ro_lock |=
EXT_CSD_BOOT_WP_B_PWR_WP_EN;
break;
default:
pr_err("%s: unknown driver specific operation\n",
md->disk->disk_name);
ret = -EINVAL;
break;
}
mq_rq->drv_op_result = ret;
blk_end_request_all(req, ret);
}
static void mmc_blk_issue_discard_rq(struct mmc_queue *mq, struct request *req)
{
struct mmc_blk_data *md = mq->blkdata;
struct mmc_card *card = md->queue.card;
unsigned int from, nr, arg;
int err = 0, type = MMC_BLK_DISCARD;
blk_status_t status = BLK_STS_OK;
if (!mmc_can_erase(card)) {
status = BLK_STS_NOTSUPP;
goto fail;
}
from = blk_rq_pos(req);
nr = blk_rq_sectors(req);
if (mmc_can_discard(card))
arg = MMC_DISCARD_ARG;
else if (mmc_can_trim(card))
arg = MMC_TRIM_ARG;
else
arg = MMC_ERASE_ARG;
do {
err = 0;
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)
err = mmc_erase(card, from, nr, arg);
} while (err == -EIO && !mmc_blk_reset(md, card->host, type));
if (err)
status = BLK_STS_IOERR;
else
mmc_blk_reset_success(md, type);
fail:
blk_end_request(req, status, blk_rq_bytes(req));
}
static void mmc_blk_issue_secdiscard_rq(struct mmc_queue *mq,
struct request *req)
{
struct mmc_blk_data *md = mq->blkdata;
struct mmc_card *card = md->queue.card;
unsigned int from, nr, arg;
int err = 0, type = MMC_BLK_SECDISCARD;
blk_status_t status = BLK_STS_OK;
if (!(mmc_can_secure_erase_trim(card))) {
status = BLK_STS_NOTSUPP;
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;
retry:
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_retry;
}
err = mmc_erase(card, from, nr, arg);
if (err == -EIO)
goto out_retry;
if (err) {
status = BLK_STS_IOERR;
goto out;
}
if (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_retry;
}
err = mmc_erase(card, from, nr, MMC_SECURE_TRIM2_ARG);
if (err == -EIO)
goto out_retry;
if (err) {
status = BLK_STS_IOERR;
goto out;
}
}
out_retry:
if (err && !mmc_blk_reset(md, card->host, type))
goto retry;
if (!err)
mmc_blk_reset_success(md, type);
out:
blk_end_request(req, status, blk_rq_bytes(req));
}
static void mmc_blk_issue_flush(struct mmc_queue *mq, struct request *req)
{
struct mmc_blk_data *md = mq->blkdata;
struct mmc_card *card = md->queue.card;
int ret = 0;
ret = mmc_flush_cache(card);
blk_end_request_all(req, ret ? BLK_STS_IOERR : BLK_STS_OK);
}
/*
* 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(blk_rq_pos(req), 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_CARD_ECC_FAILED | /* Card ECC failed */ \
R1_CC_ERROR | /* Card controller error */ \
R1_ERROR) /* General/unknown error */
static void mmc_blk_eval_resp_error(struct mmc_blk_request *brq)
{
u32 val;
/*
* Per the SD specification(physical layer version 4.10)[1],
* section 4.3.3, it explicitly states that "When the last
* block of user area is read using CMD18, the host should
* ignore OUT_OF_RANGE error that may occur even the sequence
* is correct". And JESD84-B51 for eMMC also has a similar
* statement on section 6.8.3.
*
* Multiple block read/write could be done by either predefined
* method, namely CMD23, or open-ending mode. For open-ending mode,
* we should ignore the OUT_OF_RANGE error as it's normal behaviour.
*
* However the spec[1] doesn't tell us whether we should also
* ignore that for predefined method. But per the spec[1], section
* 4.15 Set Block Count Command, it says"If illegal block count
* is set, out of range error will be indicated during read/write
* operation (For example, data transfer is stopped at user area
* boundary)." In another word, we could expect a out of range error
* in the response for the following CMD18/25. And if argument of
* CMD23 + the argument of CMD18/25 exceed the max number of blocks,
* we could also expect to get a -ETIMEDOUT or any error number from
* the host drivers due to missing data response(for write)/data(for
* read), as the cards will stop the data transfer by itself per the
* spec. So we only need to check R1_OUT_OF_RANGE for open-ending mode.
*/
if (!brq->stop.error) {
bool oor_with_open_end;
/* If there is no error yet, check R1 response */
val = brq->stop.resp[0] & CMD_ERRORS;
oor_with_open_end = val & R1_OUT_OF_RANGE && !brq->mrq.sbc;
if (val && !oor_with_open_end)
brq->stop.error = -EIO;
}
}
static enum mmc_blk_status mmc_blk_err_check(struct mmc_card *card,
struct mmc_async_req *areq)
{
struct mmc_queue_req *mq_mrq = container_of(areq, struct mmc_queue_req,
areq);
struct mmc_blk_request *brq = &mq_mrq->brq;
struct request *req = mmc_queue_req_to_req(mq_mrq);
int need_retune = card->host->need_retune;
bool ecc_err = false;
bool gen_err = false;
/*
* 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.
*/
mmc_blk_eval_resp_error(brq);
if (brq->sbc.error || brq->cmd.error ||
brq->stop.error || brq->data.error) {
switch (mmc_blk_cmd_recovery(card, req, brq, &ecc_err, &gen_err)) {
case ERR_RETRY:
return MMC_BLK_RETRY;
case ERR_ABORT:
return MMC_BLK_ABORT;
case ERR_NOMEDIUM:
return MMC_BLK_NOMEDIUM;
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) {
int err;
/* Check stop command response */
if (brq->stop.resp[0] & R1_ERROR) {
pr_err("%s: %s: general error sending stop command, stop cmd response %#x\n",
req->rq_disk->disk_name, __func__,
brq->stop.resp[0]);
gen_err = true;
}
err = card_busy_detect(card, MMC_BLK_TIMEOUT_MS, false, req,
&gen_err);
if (err)
return MMC_BLK_CMD_ERR;
}
/* if general error occurs, retry the write operation. */
if (gen_err) {
pr_warn("%s: retrying write for general error\n",
req->rq_disk->disk_name);
return MMC_BLK_RETRY;
}
/* Some errors (ECC) are flagged on the next commmand, so check stop, too */
if (brq->data.error || brq->stop.error) {
if (need_retune && !brq->retune_retry_done) {
pr_debug("%s: retrying because a re-tune was needed\n",
req->rq_disk->disk_name);
brq->retune_retry_done = 1;
return MMC_BLK_RETRY;
}
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 ?: brq->stop.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 (ecc_err)
return MMC_BLK_ECC_ERR;
return MMC_BLK_DATA_ERR;
} else {
return MMC_BLK_CMD_ERR;
}
}
if (!brq->data.bytes_xfered)
return MMC_BLK_RETRY;
if (blk_rq_bytes(req) != brq->data.bytes_xfered)
return MMC_BLK_PARTIAL;
return MMC_BLK_SUCCESS;
}
static void mmc_blk_data_prep(struct mmc_queue *mq, struct mmc_queue_req *mqrq,
int disable_multi, bool *do_rel_wr,
bool *do_data_tag)
{
struct mmc_blk_data *md = mq->blkdata;
struct mmc_card *card = md->queue.card;
struct mmc_blk_request *brq = &mqrq->brq;
struct request *req = mmc_queue_req_to_req(mqrq);
/*
* Reliable writes are used to implement Forced Unit Access and
* are supported only on MMCs.
*/
*do_rel_wr = (req->cmd_flags & REQ_FUA) &&
rq_data_dir(req) == WRITE &&
(md->flags & MMC_BLK_REL_WR);
memset(brq, 0, sizeof(struct mmc_blk_request));
brq->mrq.data = &brq->data;
brq->stop.opcode = MMC_STOP_TRANSMISSION;
brq->stop.arg = 0;
if (rq_data_dir(req) == READ) {
brq->data.flags = MMC_DATA_READ;
brq->stop.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
} else {
brq->data.flags = MMC_DATA_WRITE;
brq->stop.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
}
brq->data.blksz = 512;
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;
if (brq->data.blocks > 1) {
/*
* 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;
/*
* Some controllers have HW issues while operating
* in multiple I/O mode
*/
if (card->host->ops->multi_io_quirk)
brq->data.blocks = card->host->ops->multi_io_quirk(card,
(rq_data_dir(req) == READ) ?
MMC_DATA_READ : MMC_DATA_WRITE,
brq->data.blocks);
}
if (*do_rel_wr)
mmc_apply_rel_rw(brq, card, req);
/*
* Data tag is used only during writing meta data to speed
* up write and any subsequent read of this meta data
*/
*do_data_tag = card->ext_csd.data_tag_unit_size &&
(req->cmd_flags & REQ_META) &&
(rq_data_dir(req) == WRITE) &&
((brq->data.blocks * brq->data.blksz) >=
card->ext_csd.data_tag_unit_size);
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->areq.mrq = &brq->mrq;
mmc_queue_bounce_pre(mqrq);
}
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 = mmc_queue_req_to_req(mqrq);
struct mmc_blk_data *md = mq->blkdata;
bool do_rel_wr, do_data_tag;
mmc_blk_data_prep(mq, mqrq, disable_multi, &do_rel_wr, &do_data_tag);
brq->mrq.cmd = &brq->cmd;
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;
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;
}
brq->cmd.opcode = rq_data_dir(req) == READ ? readcmd : writecmd;
/*
* 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) ||
do_data_tag)) {
brq->sbc.opcode = MMC_SET_BLOCK_COUNT;
brq->sbc.arg = brq->data.blocks |
(do_rel_wr ? (1 << 31) : 0) |
(do_data_tag ? (1 << 29) : 0);
brq->sbc.flags = MMC_RSP_R1 | MMC_CMD_AC;
brq->mrq.sbc = &brq->sbc;
}
mqrq->areq.err_check = mmc_blk_err_check;
}
static bool mmc_blk_rw_cmd_err(struct mmc_blk_data *md, struct mmc_card *card,
struct mmc_blk_request *brq, struct request *req,
bool old_req_pending)
{
bool req_pending;
/*
* 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;
int err;
err = mmc_sd_num_wr_blocks(card, &blocks);
if (err)
req_pending = old_req_pending;
else
req_pending = blk_end_request(req, 0, blocks << 9);
} else {
req_pending = blk_end_request(req, 0, brq->data.bytes_xfered);
}
return req_pending;
}
static void mmc_blk_rw_cmd_abort(struct mmc_queue *mq, struct mmc_card *card,
struct request *req,
struct mmc_queue_req *mqrq)
{
if (mmc_card_removed(card))
req->rq_flags |= RQF_QUIET;
while (blk_end_request(req, BLK_STS_IOERR, blk_rq_cur_bytes(req)));
mq->qcnt--;
}
/**
* mmc_blk_rw_try_restart() - tries to restart the current async request
* @mq: the queue with the card and host to restart
* @req: a new request that want to be started after the current one
*/
static void mmc_blk_rw_try_restart(struct mmc_queue *mq, struct request *req,
struct mmc_queue_req *mqrq)
{
if (!req)
return;
/*
* If the card was removed, just cancel everything and return.
*/
if (mmc_card_removed(mq->card)) {
req->rq_flags |= RQF_QUIET;
blk_end_request_all(req, BLK_STS_IOERR);
mq->qcnt--; /* FIXME: just set to 0? */
return;
}
/* Else proceed and try to restart the current async request */
mmc_blk_rw_rq_prep(mqrq, mq->card, 0, mq);
mmc_start_areq(mq->card->host, &mqrq->areq, NULL);
}
static void mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *new_req)
{
struct mmc_blk_data *md = mq->blkdata;
struct mmc_card *card = md->queue.card;
struct mmc_blk_request *brq;
int disable_multi = 0, retry = 0, type, retune_retry_done = 0;
enum mmc_blk_status status;
struct mmc_queue_req *mqrq_cur = NULL;
struct mmc_queue_req *mq_rq;
struct request *old_req;
struct mmc_async_req *new_areq;
struct mmc_async_req *old_areq;
bool req_pending = true;
if (new_req) {
mqrq_cur = req_to_mmc_queue_req(new_req);
mq->qcnt++;
}
if (!mq->qcnt)
return;
do {
if (new_req) {
/*
* When 4KB native sector is enabled, only 8 blocks
* multiple read or write is allowed
*/
if (mmc_large_sector(card) &&
!IS_ALIGNED(blk_rq_sectors(new_req), 8)) {
pr_err("%s: Transfer size is not 4KB sector size aligned\n",
new_req->rq_disk->disk_name);
mmc_blk_rw_cmd_abort(mq, card, new_req, mqrq_cur);
return;
}
mmc_blk_rw_rq_prep(mqrq_cur, card, 0, mq);
new_areq = &mqrq_cur->areq;
} else
new_areq = NULL;
old_areq = mmc_start_areq(card->host, new_areq, &status);
if (!old_areq) {
/*
* We have just put the first request into the pipeline
* and there is nothing more to do until it is
* complete.
*/
return;
}
/*
* An asynchronous request has been completed and we proceed
* to handle the result of it.
*/
mq_rq = container_of(old_areq, struct mmc_queue_req, areq);
brq = &mq_rq->brq;
old_req = mmc_queue_req_to_req(mq_rq);
type = rq_data_dir(old_req) == READ ? MMC_BLK_READ : MMC_BLK_WRITE;
mmc_queue_bounce_post(mq_rq);
switch (status) {
case MMC_BLK_SUCCESS:
case MMC_BLK_PARTIAL:
/*
* A block was successfully transferred.
*/
mmc_blk_reset_success(md, type);
req_pending = blk_end_request(old_req, BLK_STS_OK,
brq->data.bytes_xfered);
/*
* If the blk_end_request function returns non-zero even
* though all data has been transferred and no errors
* were returned by the host controller, it's a bug.
*/
if (status == MMC_BLK_SUCCESS && req_pending) {
pr_err("%s BUG rq_tot %d d_xfer %d\n",
__func__, blk_rq_bytes(old_req),
brq->data.bytes_xfered);
mmc_blk_rw_cmd_abort(mq, card, old_req, mq_rq);
return;
}
break;
case MMC_BLK_CMD_ERR:
req_pending = mmc_blk_rw_cmd_err(md, card, brq, old_req, req_pending);
if (mmc_blk_reset(md, card->host, type)) {
if (req_pending)
mmc_blk_rw_cmd_abort(mq, card, old_req, mq_rq);
else
mq->qcnt--;
mmc_blk_rw_try_restart(mq, new_req, mqrq_cur);
return;
}
if (!req_pending) {
mq->qcnt--;
mmc_blk_rw_try_restart(mq, new_req, mqrq_cur);
return;
}
break;
case MMC_BLK_RETRY:
retune_retry_done = brq->retune_retry_done;
if (retry++ < 5)
break;
/* Fall through */
case MMC_BLK_ABORT:
if (!mmc_blk_reset(md, card->host, type))
break;
mmc_blk_rw_cmd_abort(mq, card, old_req, mq_rq);
mmc_blk_rw_try_restart(mq, new_req, mqrq_cur);
return;
case MMC_BLK_DATA_ERR: {
int err;
err = mmc_blk_reset(md, card->host, type);
if (!err)
break;
if (err == -ENODEV) {
mmc_blk_rw_cmd_abort(mq, card, old_req, mq_rq);
mmc_blk_rw_try_restart(mq, new_req, mqrq_cur);
return;
}
/* Fall through */
}
case MMC_BLK_ECC_ERR:
if (brq->data.blocks > 1) {
/* Redo read one sector at a time */
pr_warn("%s: retrying using single block read\n",
old_req->rq_disk->disk_name);
disable_multi = 1;
break;
}
/*
* After an error, we redo I/O one sector at a
* time, so we only reach here after trying to
* read a single sector.
*/
req_pending = blk_end_request(old_req, BLK_STS_IOERR,
brq->data.blksz);
if (!req_pending) {
mq->qcnt--;
mmc_blk_rw_try_restart(mq, new_req, mqrq_cur);
return;
}
break;
case MMC_BLK_NOMEDIUM:
mmc_blk_rw_cmd_abort(mq, card, old_req, mq_rq);
mmc_blk_rw_try_restart(mq, new_req, mqrq_cur);
return;
default:
pr_err("%s: Unhandled return value (%d)",
old_req->rq_disk->disk_name, status);
mmc_blk_rw_cmd_abort(mq, card, old_req, mq_rq);
mmc_blk_rw_try_restart(mq, new_req, mqrq_cur);
return;
}
if (req_pending) {
/*
* In case of a incomplete request
* prepare it again and resend.
*/
mmc_blk_rw_rq_prep(mq_rq, card,
disable_multi, mq);
mmc_start_areq(card->host,
&mq_rq->areq, NULL);
mq_rq->brq.retune_retry_done = retune_retry_done;
}
} while (req_pending);
mq->qcnt--;
}
void mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
{
int ret;
struct mmc_blk_data *md = mq->blkdata;
struct mmc_card *card = md->queue.card;
if (req && !mq->qcnt)
/* claim host only for the first request */
mmc_get_card(card);
ret = mmc_blk_part_switch(card, md);
if (ret) {
if (req) {
blk_end_request_all(req, BLK_STS_IOERR);
}
goto out;
}
if (req) {
switch (req_op(req)) {
case REQ_OP_DRV_IN:
case REQ_OP_DRV_OUT:
/*
* Complete ongoing async transfer before issuing
* ioctl()s
*/
if (mq->qcnt)
mmc_blk_issue_rw_rq(mq, NULL);
mmc_blk_issue_drv_op(mq, req);
break;
case REQ_OP_DISCARD:
/*
* Complete ongoing async transfer before issuing
* discard.
*/
if (mq->qcnt)
mmc_blk_issue_rw_rq(mq, NULL);
mmc_blk_issue_discard_rq(mq, req);
break;
case REQ_OP_SECURE_ERASE:
/*
* Complete ongoing async transfer before issuing
* secure erase.
*/
if (mq->qcnt)
mmc_blk_issue_rw_rq(mq, NULL);
mmc_blk_issue_secdiscard_rq(mq, req);
break;
case REQ_OP_FLUSH:
/*
* Complete ongoing async transfer before issuing
* flush.
*/
if (mq->qcnt)
mmc_blk_issue_rw_rq(mq, NULL);
mmc_blk_issue_flush(mq, req);
break;
default:
/* Normal request, just issue it */
mmc_blk_issue_rw_rq(mq, req);
card->host->context_info.is_waiting_last_req = false;
break;
}
} else {
/* No request, flushing the pipeline with NULL */
mmc_blk_issue_rw_rq(mq, NULL);
card->host->context_info.is_waiting_last_req = false;
}
out:
if (!mq->qcnt)
mmc_put_card(card);
}
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,
int area_type)
{
struct mmc_blk_data *md;
int devidx, ret;
devidx = ida_simple_get(&mmc_blk_ida, 0, max_devices, GFP_KERNEL);
if (devidx < 0)
return ERR_PTR(devidx);
md = kzalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
if (!md) {
ret = -ENOMEM;
goto out;
}
md->area_type = area_type;
/*
* 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.blkdata = 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->parent = parent;
set_disk_ro(md->disk, md->read_only || default_ro);
md->disk->flags = GENHD_FL_EXT_DEVT;
if (area_type & (MMC_BLK_DATA_AREA_RPMB | MMC_BLK_DATA_AREA_BOOT))
md->disk->flags |= GENHD_FL_NO_PART_SCAN;
/*
* 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%u%s", card->host->index, subname ? subname : "");
if (mmc_card_mmc(card))
blk_queue_logical_block_size(md->queue.queue,
card->ext_csd.data_sector_size);
else
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) &&
card->csd.mmca_vsn >= CSD_SPEC_VER_3) ||
(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_write_cache(md->queue.queue, true, true);
}
return md;
err_putdisk:
put_disk(md->disk);
err_kfree:
kfree(md);
out:
ida_simple_remove(&mmc_blk_ida, devidx);
return ERR_PTR(ret);
}
static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
{
sector_t size;
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 = (typeof(sector_t))card->csd.capacity
<< (card->csd.read_blkbits - 9);
}
return mmc_blk_alloc_req(card, &card->dev, size, false, NULL,
MMC_BLK_DATA_AREA_MAIN);
}
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,
int area_type)
{
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, area_type);
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), 512, STRING_UNITS_2,
cap_str, sizeof(cap_str));
pr_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;
}
/* MMC Physical partitions consist of two boot partitions and
* up to four general purpose partitions.
* For each partition enabled in EXT_CSD a block device will be allocatedi
* to provide access to the partition.
*/
static int mmc_blk_alloc_parts(struct mmc_card *card, struct mmc_blk_data *md)
{
int idx, ret = 0;
if (!mmc_card_mmc(card))
return 0;
for (idx = 0; idx < card->nr_parts; idx++) {
if (card->part[idx].size) {
ret = mmc_blk_alloc_part(card, md,
card->part[idx].part_cfg,
card->part[idx].size >> 9,
card->part[idx].force_ro,
card->part[idx].name,
card->part[idx].area_type);
if (ret)
return ret;
}
}
return ret;
}
static void mmc_blk_remove_req(struct mmc_blk_data *md)
{
struct mmc_card *card;
if (md) {
/*
* Flush remaining requests and free queues. It
* is freeing the queue that stops new requests
* from being accepted.
*/
card = md->queue.card;
spin_lock_irq(md->queue.queue->queue_lock);
queue_flag_set(QUEUE_FLAG_BYPASS, md->queue.queue);
spin_unlock_irq(md->queue.queue->queue_lock);
blk_set_queue_dying(md->queue.queue);
mmc_cleanup_queue(&md->queue);
if (md->disk->flags & GENHD_FL_UP) {
device_remove_file(disk_to_dev(md->disk), &md->force_ro);
if ((md->area_type & MMC_BLK_DATA_AREA_BOOT) &&
card->ext_csd.boot_ro_lockable)
device_remove_file(disk_to_dev(md->disk),
&md->power_ro_lock);
del_gendisk(md->disk);
}
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;
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;
struct mmc_card *card = md->queue.card;
device_add_disk(md->parent, 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)
goto force_ro_fail;
if ((md->area_type & MMC_BLK_DATA_AREA_BOOT) &&
card->ext_csd.boot_ro_lockable) {
umode_t mode;
if (card->ext_csd.boot_ro_lock & EXT_CSD_BOOT_WP_B_PWR_WP_DIS)
mode = S_IRUGO;
else
mode = S_IRUGO | S_IWUSR;
md->power_ro_lock.show = power_ro_lock_show;
md->power_ro_lock.store = power_ro_lock_store;
sysfs_attr_init(&md->power_ro_lock.attr);
md->power_ro_lock.attr.mode = mode;
md->power_ro_lock.attr.name =
"ro_lock_until_next_power_on";
ret = device_create_file(disk_to_dev(md->disk),
&md->power_ro_lock);
if (ret)
goto power_ro_lock_fail;
}
return ret;
power_ro_lock_fail:
device_remove_file(disk_to_dev(md->disk), &md->force_ro);
force_ro_fail:
del_gendisk(md->disk);
return ret;
}
static int mmc_blk_probe(struct mmc_card *card)
{
struct mmc_blk_data *md, *part_md;
char cap_str[10];
/*
* Check that the card supports the command class(es) we need.
*/
if (!(card->csd.cmdclass & CCC_BLOCK_READ))
return -ENODEV;
mmc_fixup_device(card, mmc_blk_fixups);
md = mmc_blk_alloc(card);
if (IS_ERR(md))
return PTR_ERR(md);
string_get_size((u64)get_capacity(md->disk), 512, STRING_UNITS_2,
cap_str, sizeof(cap_str));
pr_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;
dev_set_drvdata(&card->dev, md);
if (mmc_add_disk(md))
goto out;
list_for_each_entry(part_md, &md->part, part) {
if (mmc_add_disk(part_md))
goto out;
}
pm_runtime_set_autosuspend_delay(&card->dev, 3000);
pm_runtime_use_autosuspend(&card->dev);
/*
* Don't enable runtime PM for SD-combo cards here. Leave that
* decision to be taken during the SDIO init sequence instead.
*/
if (card->type != MMC_TYPE_SD_COMBO) {
pm_runtime_set_active(&card->dev);
pm_runtime_enable(&card->dev);
}
return 0;
out:
mmc_blk_remove_parts(card, md);
mmc_blk_remove_req(md);
return 0;
}
static void mmc_blk_remove(struct mmc_card *card)
{
struct mmc_blk_data *md = dev_get_drvdata(&card->dev);
mmc_blk_remove_parts(card, md);
pm_runtime_get_sync(&card->dev);
mmc_claim_host(card->host);
mmc_blk_part_switch(card, md);
mmc_release_host(card->host);
if (card->type != MMC_TYPE_SD_COMBO)
pm_runtime_disable(&card->dev);
pm_runtime_put_noidle(&card->dev);
mmc_blk_remove_req(md);
dev_set_drvdata(&card->dev, NULL);
}
static int _mmc_blk_suspend(struct mmc_card *card)
{
struct mmc_blk_data *part_md;
struct mmc_blk_data *md = dev_get_drvdata(&card->dev);
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 void mmc_blk_shutdown(struct mmc_card *card)
{
_mmc_blk_suspend(card);
}
#ifdef CONFIG_PM_SLEEP
static int mmc_blk_suspend(struct device *dev)
{
struct mmc_card *card = mmc_dev_to_card(dev);
return _mmc_blk_suspend(card);
}
static int mmc_blk_resume(struct device *dev)
{
struct mmc_blk_data *part_md;
struct mmc_blk_data *md = dev_get_drvdata(dev);
if (md) {
/*
* 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;
}
#endif
static SIMPLE_DEV_PM_OPS(mmc_blk_pm_ops, mmc_blk_suspend, mmc_blk_resume);
static struct mmc_driver mmc_driver = {
.drv = {
.name = "mmcblk",
.pm = &mmc_blk_pm_ops,
},
.probe = mmc_blk_probe,
.remove = mmc_blk_remove,
.shutdown = mmc_blk_shutdown,
};
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 = min(MAX_DEVICES, (1 << MINORBITS) / 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");