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>
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index c742cfd..f6acf0f 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -387,6 +387,24 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
__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 @@
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
