RE: [PATCH v1] mmc: card: Adding support for sanitize in eMMC 4.5

Luca Porzio (lporzio)
2013-03-11T18:36:55Z

Hi Yaniv,

> -----Original Message-----
> From: linux-mmc-owner@vger.kernel.org [mailto:linux-mmc-
> owner@vger.kernel.org] On Behalf Of Yaniv Gardi
> Sent: Sunday, February 24, 2013 12:39 PM
> To: linux-mmc@vger.kernel.org; vgoyal@redhat.com; tj@kernel.org; linux-
> kernel@vger.kernel.org
> Cc: linux-arm-msm@vger.kernel.org; Yaniv Gardi
> Subject: [PATCH v1] mmc: card: Adding support for sanitize in eMMC 4.5
>
> The sanitize support is added as a user-app ioctl call, and
> was removed from the block-device request, since its purpose is
> to be invoked not via File-System but by a user.
> This feature deletes the unmap memory region of the eMMC card,
> by writing to a specific register in the EXT_CSD.
> unmap region is the memory region that was previously deleted
> (by erase, trim or discard operation).
> In order to avoid timeout when sanitizing large-scale cards,
> the timeout for sanitize operation is 240 seconds.
>
> Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
>
> ---
> drivers/mmc/card/block.c | 68 +++++++++++++++++++++++++++++++-----------
> ---
> drivers/mmc/card/queue.c | 2 +-
> include/linux/mmc/host.h | 1 +
> 3 files changed, 49 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
> index 21056b9..21bb8b4 100644
> --- a/drivers/mmc/card/block.c
> +++ b/drivers/mmc/card/block.c
> @@ -58,6 +58,8 @@ MODULE_ALIAS("mmc:block");
> #define INAND_CMD38_ARG_SECTRIM1 0x81
> #define INAND_CMD38_ARG_SECTRIM2 0x88
> #define MMC_BLK_TIMEOUT_MS (10 * 60 * 1000) /* 10 minute timeout
> */
> +#define MMC_SANITIZE_REQ_TIMEOUT 240000

Though I would agree that 4 minutes is a reasonable sanitize time,
the sanitize command may also depend on card size.
As such I am not sure whether it can be regarded as a constant or
needs to be proportional to card size.

> +#define MMC_EXTRACT_INDEX_FROM_ARG(x) ((x & 0x00FF0000) >> 16)
>
> static DEFINE_MUTEX(block_mutex);
>
> @@ -394,6 +396,35 @@ static int ioctl_rpmb_card_status_poll(struct mmc_card
> *card, u32 *status,
> return err;
> }
>
> +static int ioctl_do_sanitize(struct mmc_card *card)
> +{
> + int err;
> +
> + if (!(mmc_can_sanitize(card) &&
> + (card->host->caps2 & MMC_CAP2_SANITIZE))) {
> + 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);
> +

In case of Sanitize timeout, the eMMC might go in an unclear state.
May I suggest to:
- issue an HPI before leaving thus bring the eMMC back into safe status
- report the 'sanitize not complete error' and let the user decide on
Whether he wants to re-issue (i.e. continue) the sanitize or just let
it go.

Thanks,
Luca

> + pr_debug("%s: %s - SANITIZE COMPLETED\n", mmc_hostname(card->host),
> + __func__);
> +out:
> + return err;
> +}
> +
> static int mmc_blk_ioctl_cmd(struct block_device *bdev,
> struct mmc_ioc_cmd __user *ic_ptr)
> {
> @@ -496,6 +527,16 @@ static int mmc_blk_ioctl_cmd(struct block_device
> *bdev,
> goto cmd_rel_host;
> }
>
> + if (MMC_EXTRACT_INDEX_FROM_ARG(cmd.arg) == EXT_CSD_SANITIZE_START) {
> + err = ioctl_do_sanitize(card);
> +
> + if (err)
> + pr_err("%s: ioctl_do_sanitize() failed. err = %d",
> + __func__, err);
> +
> + goto cmd_rel_host;
> + }
> +
> mmc_wait_for_req(card->host, &mrq);
>
> if (cmd.error) {
> @@ -925,10 +966,10 @@ static int mmc_blk_issue_secdiscard_rq(struct
> mmc_queue *mq,
> {
> struct mmc_blk_data *md = mq->data;
> struct mmc_card *card = md->queue.card;
> - unsigned int from, nr, arg, trim_arg, erase_arg;
> + unsigned int from, nr, arg;
> int err = 0, type = MMC_BLK_SECDISCARD;
>
> - if (!(mmc_can_secure_erase_trim(card) || mmc_can_sanitize(card))) {
> + if (!(mmc_can_secure_erase_trim(card))) {
> err = -EOPNOTSUPP;
> goto out;
> }
> @@ -936,23 +977,11 @@ static int mmc_blk_issue_secdiscard_rq(struct
> mmc_queue *mq,
> from = blk_rq_pos(req);
> nr = blk_rq_sectors(req);
>
> - /* The sanitize operation is supported at v4.5 only */
> - if (mmc_can_sanitize(card)) {
> - erase_arg = MMC_ERASE_ARG;
> - trim_arg = MMC_TRIM_ARG;
> - } else {
> - erase_arg = MMC_SECURE_ERASE_ARG;
> - trim_arg = MMC_SECURE_TRIM1_ARG;
> - }
> + if (mmc_can_trim(card) && !mmc_erase_group_aligned(card, from, nr))
> + arg = MMC_SECURE_TRIM1_ARG;
> + else
> + arg = MMC_SECURE_ERASE_ARG;
>
> - if (mmc_erase_group_aligned(card, from, nr))
> - arg = erase_arg;
> - else if (mmc_can_trim(card))
> - arg = trim_arg;
> - else {
> - err = -EINVAL;
> - goto out;
> - }
> retry:
> if (card->quirks & MMC_QUIRK_INAND_CMD38) {
> err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
> @@ -988,9 +1017,6 @@ retry:
> goto out;
> }
>
> - if (mmc_can_sanitize(card))
> - err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
> - EXT_CSD_SANITIZE_START, 1, 0);
> out_retry:
> if (err && !mmc_blk_reset(md, card->host, type))
> goto retry;
> diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
> index fadf52e..483f0e8 100644
> --- a/drivers/mmc/card/queue.c
> +++ b/drivers/mmc/card/queue.c
> @@ -148,7 +148,7 @@ static void mmc_queue_setup_discard(struct
> request_queue *q,
> /* granularity must not be greater than max. discard */
> if (card->pref_erase > max_discard)
> q->limits.discard_granularity = 0;
> - if (mmc_can_secure_erase_trim(card) || mmc_can_sanitize(card))
> + if (mmc_can_secure_erase_trim(card))
> queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD, q);
> }
>
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index 61a10c1..045e9f7 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -258,6 +258,7 @@ struct mmc_host {
> #define MMC_CAP2_HC_ERASE_SZ (1 << 9) /* High-capacity erase size */
> #define MMC_CAP2_CD_ACTIVE_HIGH (1 << 10) /* Card-detect signal active
> high */
> #define MMC_CAP2_RO_ACTIVE_HIGH (1 << 11) /* Write-protect signal active
> high */
> +#define MMC_CAP2_SANITIZE (1 << 12) /* Support Sanitize */
>
> mmc_pm_flag_t pm_caps; /* supported pm features */
>
> --
> 1.7.6
> --
> Sent by a consultant of the Qualcomm Innovation Center, Inc.
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum