From 15f8b6cda53848ced93a20554584dc860baab8b7 Mon Sep 17 00:00:00 2001
From: Adrian Hunter <[email protected]> Date: Thu, 3 Jun 2010 10:47:12 +0300 Subject: [PATCH 3/4] mmc_block: Add BLKDISCARD, BLKSECDISCARD and BLKDISCARDZEROES support
Add implementations for ioctls BLKDISCARD and BLKSECDISCARD, and flag the I/O queue if the SD/MMC card zeroes erased sectors. N.B. SD/MMC cards set erased sectors either to ones or zeroes. Signed-off-by: Adrian Hunter <[email protected]> --- drivers/mmc/card/block.c | 152 ++++++++++++++++++++++++++++++++++++++++++++++ drivers/mmc/card/queue.c | 2 + 2 files changed, 154 insertions(+), 0 deletions(-) diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index cb9fbc8..67f59bc 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -31,6 +31,7 @@ #include <linux/mutex.h> #include <linux/scatterlist.h> #include <linux/string_helpers.h> +#include <linux/delay.h> #include <linux/mmc/card.h> #include <linux/mmc/host.h> @@ -138,9 +139,160 @@ mmc_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo) return 0; } +static int mmc_blk_check_eod(struct block_device *bdev, unsigned int from, + unsigned int nr) +{ + unsigned int maxsector; + + if (!nr) + return 0; + + maxsector = bdev->bd_inode->i_size >> 9; + if (maxsector && (maxsector < nr || maxsector - nr < from)) + return 1; + + return 0; +} + +static void mmc_blk_erase_throttle(struct mmc_blk_data *md) +{ + struct mmc_card *card = md->queue.card; + struct request_queue *q = md->queue.queue; + int i, ok; + + for (i = 0; i < 40; i++) { + spin_lock_irq(q->queue_lock); + ok = elv_queue_empty(q); + spin_unlock_irq(q->queue_lock); + if (ok) + break; + mmc_release_host(card->host); + msleep(50); + mmc_claim_host(card->host); + } +} + +static int mmc_blk_erase(struct mmc_blk_data *md, unsigned int from, + unsigned int nr) +{ + struct mmc_card *card = md->queue.card; + unsigned int n, arg; + int err; + + if (!mmc_can_erase(card)) + return -EOPNOTSUPP; + + if (mmc_can_trim(card)) + arg = MMC_TRIM_ARG; + else + arg = MMC_ERASE_ARG; + + mmc_claim_host(card->host); + n = card->max_erase - (from % card->max_erase); + do { + /* + * Do not allow the BLKDISCARD ioctl to have priority over + * scheduled I/O. + */ + mmc_blk_erase_throttle(md); + if (n > nr) + n = nr; + err = mmc_erase(card, from, n, arg); + if (err) + break; + from += n; + nr -= n; + n = card->max_erase; + } while (nr); + mmc_release_host(card->host); + + return err; +} + +static int mmc_blk_secure_erase(struct mmc_blk_data *md, unsigned int from, + unsigned int nr) +{ + struct mmc_card *card = md->queue.card; + unsigned int arg; + int err; + + if (!mmc_can_secure_erase_trim(card)) + return -EOPNOTSUPP; + + if (mmc_can_trim(card) && !mmc_erase_group_aligned(card, from, nr)) + arg = MMC_SECURE_TRIM1_ARG; + else + arg = MMC_SECURE_ERASE_ARG; + + mmc_claim_host(card->host); + /* + * Secure erase can be very inefficient when used with any size + * significantly smaller than the size of the whole card, so do not + * break up the original request, but still wait for scheduled I/O + * in case the user is trying to securely erase one partition in + * small pieces while still using another partition on the same card. + */ + mmc_blk_erase_throttle(md); + err = mmc_erase(card, from, nr, arg); + if (!err && arg == MMC_SECURE_TRIM1_ARG) + err = mmc_erase(card, from, nr, MMC_SECURE_TRIM2_ARG); + mmc_release_host(card->host); + + return err; +} + +static int mmc_blk_ioctl_discard(struct block_device *bdev, uint64_t start, + uint64_t len, int secure) +{ + struct mmc_blk_data *md = bdev->bd_disk->private_data; + unsigned int from, nr; + + if ((start & 511) || (len & 511)) + return -EINVAL; + + start >>= 9; + len >>= 9; + + if (start > UINT_MAX || len > UINT_MAX) + return -EINVAL; + + from = start; + nr = len; + + if (mmc_blk_check_eod(bdev, from, nr)) + return -EINVAL; + + if (bdev != bdev->bd_contains) + from += bdev->bd_part->start_sect; + + if (secure) + return mmc_blk_secure_erase(md, from, nr); + else + return mmc_blk_erase(md, from, nr); +} + +static int mmc_blk_ioctl(struct block_device *bdev, fmode_t mode, + unsigned cmd, unsigned long arg) +{ + uint64_t range[2]; + int secure = 0; + + switch (cmd) { + case BLKSECDISCARD: + secure = 1; + case BLKDISCARD: + if (copy_from_user(range, (void __user *)arg, sizeof(range))) + return -EFAULT; + + return mmc_blk_ioctl_discard(bdev, range[0], range[1], secure); + } + return -ENOTTY; +} + static const struct block_device_operations mmc_bdops = { .open = mmc_blk_open, .release = mmc_blk_release, + .ioctl = mmc_blk_ioctl, .getgeo = mmc_blk_getgeo, .owner = THIS_MODULE, }; diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c index d6ded24..9b760d7 100644 --- a/drivers/mmc/card/queue.c +++ b/drivers/mmc/card/queue.c @@ -130,6 +130,8 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock blk_queue_prep_rq(mq->queue, mmc_prep_request); blk_queue_ordered(mq->queue, QUEUE_ORDERED_DRAIN, NULL); queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue); + if (card->erased_byte == 0) + mq->queue->limits.discard_zeroes_data = 1; #ifdef CONFIG_MMC_BLOCK_BOUNCE if (host->max_hw_segs == 1) { -- 1.6.3.3 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
