From a5f5774c55a2e3ed75f4d6c5556b7bfcb726e6f0 Mon Sep 17 00:00:00 2001 From: Jon Hunter Date: Tue, 22 Sep 2015 10:27:53 +0100 Subject: [PATCH] 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 . Signed-off-by: Seshagiri Holi Signed-off-by: Jon Hunter Signed-off-by: Ulf Hansson --- drivers/mmc/card/block.c | 206 ++++++++++++++++++++++++--------- include/uapi/linux/mmc/ioctl.h | 19 ++- 2 files changed, 169 insertions(+), 56 deletions(-) diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index c742cfd7674e..f6acf0f6c410 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -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 diff --git a/include/uapi/linux/mmc/ioctl.h b/include/uapi/linux/mmc/ioctl.h index 1f5e68923929..7e385b83b9d8 100644 --- a/include/uapi/linux/mmc/ioctl.h +++ b/include/uapi/linux/mmc/ioctl.h @@ -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 */ -- 2.30.2