From patchwork Mon Apr 11 21:55:59 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Calixto X-Patchwork-Id: 698941 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id p3BLu3td016154 for ; Mon, 11 Apr 2011 21:56:09 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754404Ab1DKV4J (ORCPT ); Mon, 11 Apr 2011 17:56:09 -0400 Received: from elasmtp-banded.atl.sa.earthlink.net ([209.86.89.70]:41348 "EHLO elasmtp-banded.atl.sa.earthlink.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751986Ab1DKV4I (ORCPT ); Mon, 11 Apr 2011 17:56:08 -0400 Received: from [24.41.60.94] (helo=peruna) by elasmtp-banded.atl.sa.earthlink.net with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.67) (envelope-from ) id 1Q9P5a-0001cj-SO; Mon, 11 Apr 2011 17:56:07 -0400 Date: Mon, 11 Apr 2011 14:55:59 -0700 (PDT) From: John Calixto To: linux-mmc@vger.kernel.org cc: =?ISO-8859-2?Q?Micha=B3_Miros=B3aw?= , Arnd Bergmann , Chris Ball , Andrei Warkentin Subject: [PATCH v4] mmc: Add ioctl to let userspace apps send ACMDs In-Reply-To: Message-ID: References: User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 X-ELNK-Trace: 27f846e6922d8dd3bccdfc2343d5c9349ef193a6bfc3dd48374bad54a3d87b0191ac94f1c10e0943387f7b89c61deb1d350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 24.41.60.94 Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Mon, 11 Apr 2011 21:56:10 +0000 (UTC) Sending ACMDs from userspace is useful for such things as: - The security application of an SD card (SD Specification, Part 3, Security) - SD passthrough for virtual machines Tested on TI PCIxx12 (SDHCI), Sigma Designs SMP8652 SoC, TI OMAP3621 SoC, TI OMAP3630 SoC, Samsung S5PC110 SoC, Qualcomm MSM7200A SoC. Signed-off-by: John Calixto Reviewed-by: Andrei Warkentin --- drivers/mmc/card/block.c | 196 +++++++++++++++++++++++++++++++++++++++++++++ drivers/mmc/core/sd_ops.c | 3 +- include/linux/Kbuild | 1 + include/linux/mmc/Kbuild | 1 + include/linux/mmc/core.h | 1 + include/linux/mmc/ioctl.h | 32 +++++++ 6 files changed, 233 insertions(+), 1 deletions(-) create mode 100644 include/linux/mmc/Kbuild create mode 100644 include/linux/mmc/ioctl.h diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index 61d233a..5e09801 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -31,7 +31,10 @@ #include #include #include +#include +#include +#include #include #include #include @@ -158,11 +161,204 @@ mmc_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo) return 0; } +struct mmc_blk_ioc_data { + struct mmc_ioc_cmd ic; + unsigned char *buf; + size_t 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 copy_err; + } + + if (copy_from_user(&idata->ic, user, sizeof(idata->ic))) { + err = -EFAULT; + goto copy_err; + } + + idata->buf_bytes = idata->ic.blksz * idata->ic.blocks; + + idata->buf = kzalloc(idata->buf_bytes, GFP_KERNEL); + if (!idata->buf) { + err = -ENOMEM; + goto copy_err; + } + + if (copy_from_user(idata->buf, (u8 *) user->data_ptr, idata->buf_bytes)) { + err = -EFAULT; + goto copy_err; + } + + return idata; + +copy_err: + kfree(idata->buf); + kfree(idata); + return ERR_PTR(err); + +} + +static int mmc_blk_ioctl_acmd(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 acmd_done; + } + + card = md->queue.card; + if (IS_ERR(card)) { + err = PTR_ERR(card); + goto acmd_done; + } + + mmc_claim_host(card->host); + + err = mmc_app_cmd(card->host, card); + if (err) + goto acmd_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 acmd_rel_host; + } + if (data.error) { + dev_err(mmc_dev(card->host), "%s: data error %d\n", + __func__, data.error); + err = data.error; + goto acmd_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 acmd_rel_host; + } + + if (!idata->ic.write_flag) { + if (copy_to_user((u8 *) ic_ptr->data_ptr, idata->buf, idata->buf_bytes)) { + err = -EFAULT; + goto acmd_rel_host; + } + } + +acmd_rel_host: + mmc_release_host(card->host); + +acmd_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; + mutex_lock(&block_mutex); + if (cmd == MMC_IOC_ACMD) + ret = mmc_blk_ioctl_acmd(bdev, (struct mmc_ioc_cmd __user *)arg); + mutex_unlock(&block_mutex); + return ret; +} + +#ifdef CONFIG_COMPAT +static int mmc_blk_compat_ioctl(struct block_device *bdev, fmode_t mode, + unsigned int cmd, unsigned long arg) +{ + struct mmc_ioc_cmd __user *ic = (struct mmc_ioc_cmd __user *) arg; + ic->data_ptr = ic->data_ptr & 0xffffffff; + return mmc_blk_ioctl(bdev, mode, cmd, 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 }; struct mmc_blk_request { diff --git a/drivers/mmc/core/sd_ops.c b/drivers/mmc/core/sd_ops.c index 797cdb5..990dd43 100644 --- a/drivers/mmc/core/sd_ops.c +++ b/drivers/mmc/core/sd_ops.c @@ -20,7 +20,7 @@ #include "core.h" #include "sd_ops.h" -static int mmc_app_cmd(struct mmc_host *host, struct mmc_card *card) +int mmc_app_cmd(struct mmc_host *host, struct mmc_card *card) { int err; struct mmc_command cmd; @@ -48,6 +48,7 @@ static int mmc_app_cmd(struct mmc_host *host, struct mmc_card *card) return 0; } +EXPORT_SYMBOL_GPL(mmc_app_cmd); /** * mmc_wait_for_app_cmd - start an application command and wait for diff --git a/include/linux/Kbuild b/include/linux/Kbuild index 75cf611..ed38527 100644 --- a/include/linux/Kbuild +++ b/include/linux/Kbuild @@ -4,6 +4,7 @@ header-y += caif/ header-y += dvb/ header-y += hdlc/ header-y += isdn/ +header-y += mmc/ header-y += nfsd/ header-y += raid/ header-y += spi/ diff --git a/include/linux/mmc/Kbuild b/include/linux/mmc/Kbuild new file mode 100644 index 0000000..1fb2644 --- /dev/null +++ b/include/linux/mmc/Kbuild @@ -0,0 +1 @@ +header-y += ioctl.h diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h index 07f27af..bfc6127 100644 --- a/include/linux/mmc/core.h +++ b/include/linux/mmc/core.h @@ -133,6 +133,7 @@ struct mmc_card; extern void mmc_wait_for_req(struct mmc_host *, struct mmc_request *); extern int mmc_wait_for_cmd(struct mmc_host *, struct mmc_command *, int); +extern int mmc_app_cmd(struct mmc_host *, struct mmc_card *); extern int mmc_wait_for_app_cmd(struct mmc_host *, struct mmc_card *, struct mmc_command *, int); diff --git a/include/linux/mmc/ioctl.h b/include/linux/mmc/ioctl.h new file mode 100644 index 0000000..d0f11fb --- /dev/null +++ b/include/linux/mmc/ioctl.h @@ -0,0 +1,32 @@ +#ifndef _MMC_IOCTL_H +#define _MMC_IOCTL_H +struct mmc_ioc_cmd { + /* implies direction of data. true = write, false = read */ + int write_flag; + + __u32 opcode; + __u32 arg; + __u32 response[4]; /* CMD response */ + unsigned int flags; + unsigned int blksz; + unsigned int blocks; + + /* + * Sleep at least postsleep_min_us useconds, and at most + * postsleep_max_us useconds *after* issuing command. Needed for some + * read commands for which cards have no other way of indicating + * they're ready for the next command (i.e. there is no equivalent of a + * "busy" indicator for read operations). + */ + unsigned int postsleep_min_us; + unsigned int postsleep_max_us; + + /* + * Override driver-computed timeouts. Note the difference in units! + */ + unsigned int data_timeout_ns; + unsigned int cmd_timeout_ms; + __u64 data_ptr; /* DAT buffer */ +}; +#define MMC_IOC_ACMD _IOWR(MMC_BLOCK_MAJOR, 0, struct mmc_ioc_cmd) +#endif /* _MMC_IOCTL_H */