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mmc: block: Add new ioctl to send multi commands 

Certain eMMC devices allow vendor specific device information to be read
via a sequence of vendor commands. These vendor commands must be issued
in sequence and an atomic fashion. One way to support this would be to
add an ioctl function for sending a sequence of commands to the device
atomically as proposed here. These multi commands are simple array of
the existing mmc_ioc_cmd structure.

The structure passed via the ioctl uses a __u64 type to specify the number
of commands (so that the structure is aligned on a 64-bit boundary) and a
zero length array as a header for list of commands to be issued. The
maximum number of commands that can be sent is determined by
MMC_IOC_MAX_CMDS (which defaults to 255 and should be more than
sufficient).

This based upon work by Seshagiri Holi <sholi@nvidia.com>.

Signed-off-by: Seshagiri Holi <sholi@nvidia.com>
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Jon Hunter 2015-09-22 10:27:53 +01:00 committed by Ulf Hansson
parent aaa58d0e93
commit a5f5774c55
2 changed files with 169 additions and 56 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

206
drivers/mmc/card/block.c
View File

@ -387,6 +387,24 @@ 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)
{
@ -447,12 +465,9 @@ out:
return err;
}
static int mmc_blk_ioctl_cmd(struct block_device *bdev,
struct mmc_ioc_cmd __user *ic_ptr)
static int __mmc_blk_ioctl_cmd(struct mmc_card *card, struct mmc_blk_data *md,
struct mmc_blk_ioc_data *idata)
{
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 = {NULL};
@ -461,33 +476,12 @@ static int mmc_blk_ioctl_cmd(struct block_device *bdev,
int is_rpmb = false;
u32 status = 0;
/*
* 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;
}
if (!card || !md || !idata)
return -EINVAL;
if (md->area_type & MMC_BLK_DATA_AREA_RPMB)
is_rpmb = true;
card = md->queue.card;
if (IS_ERR(card)) {
err = PTR_ERR(card);
goto cmd_done;
}
cmd.opcode = idata->ic.opcode;
cmd.arg = idata->ic.arg;
cmd.flags = idata->ic.flags;
@ -530,23 +524,21 @@ static int mmc_blk_ioctl_cmd(struct block_device *bdev,
mrq.cmd = &cmd;
mmc_get_card(card);
err = mmc_blk_part_switch(card, md);
if (err)
goto cmd_rel_host;
return err;
if (idata->ic.is_acmd) {
err = mmc_app_cmd(card->host, card);
if (err)
goto cmd_rel_host;
return err;
}
if (is_rpmb) {
err = mmc_set_blockcount(card, data.blocks,
idata->ic.write_flag & (1 << 31));
if (err)
goto cmd_rel_host;
return err;
}
if ((MMC_EXTRACT_INDEX_FROM_ARG(cmd.arg) == EXT_CSD_SANITIZE_START) &&
@ -557,7 +549,7 @@ static int mmc_blk_ioctl_cmd(struct block_device *bdev,
pr_err("%s: ioctl_do_sanitize() failed. err = %d",
__func__, err);
goto cmd_rel_host;
return err;
}
mmc_wait_for_req(card->host, &mrq);
@ -565,14 +557,12 @@ static int mmc_blk_ioctl_cmd(struct block_device *bdev,
if (cmd.error) {
dev_err(mmc_dev(card->host), "%s: cmd error %d\n",
__func__, cmd.error);
err = cmd.error;
goto cmd_rel_host;
return cmd.error;
}
if (data.error) {
dev_err(mmc_dev(card->host), "%s: data error %d\n",
__func__, data.error);
err = data.error;
goto cmd_rel_host;
return data.error;
}
/*
@ -582,18 +572,7 @@ static int mmc_blk_ioctl_cmd(struct block_device *bdev,
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;
}
}
memcpy(&(idata->ic.response), cmd.resp, sizeof(cmd.resp));
if (is_rpmb) {
/*
@ -607,9 +586,42 @@ static int mmc_blk_ioctl_cmd(struct block_device *bdev,
__func__, status, err);
}
cmd_rel_host:
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_data *md;
struct mmc_card *card;
int err;
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;
}
mmc_get_card(card);
err = __mmc_blk_ioctl_cmd(card, md, idata);
mmc_put_card(card);
if (!err)
err = mmc_blk_ioctl_copy_to_user(ic_ptr, idata);
cmd_done:
mmc_blk_put(md);
cmd_err:
@ -618,13 +630,97 @@ cmd_err:
return 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;
int i, err = -EFAULT;
__u64 num_of_cmds;
if (copy_from_user(&num_of_cmds, &user->num_of_cmds,
sizeof(num_of_cmds)))
return -EFAULT;
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)
goto cmd_err;
card = md->queue.card;
if (IS_ERR(card)) {
err = PTR_ERR(card);
goto cmd_done;
}
mmc_get_card(card);
for (i = 0; i < num_of_cmds; i++) {
err = __mmc_blk_ioctl_cmd(card, md, idata[i]);
if (err) {
mmc_put_card(card);
goto cmd_done;
}
}
mmc_put_card(card);
/* copy to user if data and response */
for (i = 0; i < num_of_cmds; i++) {
err = mmc_blk_ioctl_copy_to_user(&cmds[i], idata[i]);
if (err)
break;
}
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 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;
/*
* 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;
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

19
include/uapi/linux/mmc/ioctl.h
View File

@ -45,8 +45,24 @@ struct mmc_ioc_cmd {
};
#define mmc_ioc_cmd_set_data(ic, ptr) ic.data_ptr = (__u64)(unsigned long) ptr
#define MMC_IOC_CMD _IOWR(MMC_BLOCK_MAJOR, 0, struct mmc_ioc_cmd)
/**
* struct mmc_ioc_multi_cmd - multi command information
* @num_of_cmds: Number of commands to send. Must be equal to or less than
* MMC_IOC_MAX_CMDS.
* @cmds: Array of commands with length equal to 'num_of_cmds'
*/
struct mmc_ioc_multi_cmd {
__u64 num_of_cmds;
struct mmc_ioc_cmd cmds[0];
};
#define MMC_IOC_CMD _IOWR(MMC_BLOCK_MAJOR, 0, struct mmc_ioc_cmd)
/*
* MMC_IOC_MULTI_CMD: Used to send an array of MMC commands described by
* the structure mmc_ioc_multi_cmd. The MMC driver will issue all
* commands in array in sequence to card.
*/
#define MMC_IOC_MULTI_CMD _IOWR(MMC_BLOCK_MAJOR, 1, struct mmc_ioc_multi_cmd)
/*
* Since this ioctl is only meant to enhance (and not replace) normal access
* to the mmc bus device, an upper data transfer limit of MMC_IOC_MAX_BYTES
@ -54,4 +70,5 @@ struct mmc_ioc_cmd {
* block device operations.
*/
#define MMC_IOC_MAX_BYTES (512L * 256)
#define MMC_IOC_MAX_CMDS 255
#endif /* LINUX_MMC_IOCTL_H */