Add bounce_size under /sys/block/mmcblk0/bouncesz.
Support dynamic adjustment of bounce buffer in run-time (include mounted or
unmounted filesystem).
/sys/block/mmcblk0/bouncesz should be integer multiple of 512, the
value should be range from 4096 to 4194304.
Signed-off-by: Qiang Liu <qiang.liu@xxxxxxxxxxxxx>
---
drivers/mmc/card/block.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 44 insertions(+), 0 deletions(-)
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index a1cb21f..649bfed 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -59,6 +59,9 @@ MODULE_ALIAS("mmc:block");
#define INAND_CMD38_ARG_SECTRIM1 0x81
#define INAND_CMD38_ARG_SECTRIM2 0x88
+#define MMC_MIN_QUEUE_BOUNCESZ 4096
+#define MMC_MAX_QUEUE_BOUNCESZ 4194304
+
static DEFINE_MUTEX(block_mutex);
/*
@@ -107,6 +110,7 @@ struct mmc_blk_data {
*/
unsigned int part_curr;
struct device_attribute force_ro;
+ struct device_attribute bouncesz;
};
static DEFINE_MUTEX(open_lock);
@@ -1547,6 +1551,7 @@ static void mmc_blk_remove_req(struct mmc_blk_data *md)
del_gendisk(md->disk);
}
+ device_remove_file(disk_to_dev(md->disk), &md->bouncesz);
/* Then flush out any already in there */
mmc_cleanup_queue(&md->queue);
mmc_blk_put(md);
@@ -1609,6 +1614,33 @@ static const struct mmc_fixup blk_fixups[] =
END_FIXUP
};
+#ifdef CONFIG_MMC_BLOCK_BOUNCE
+static ssize_t mmc_bouncesz_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%u\n", mmc_queue_bouncesz);
+}
+
+static ssize_t mmc_bouncesz_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ unsigned int bouncesz;
+ struct mmc_blk_data *md;
+
+ if ((sscanf(buf, "%d", &bouncesz) != 1) ||
+ (bouncesz < MMC_MIN_QUEUE_BOUNCESZ) ||
+ (bouncesz > MMC_MAX_QUEUE_BOUNCESZ) ||
+ (bouncesz % 512 != 0))
+ return -EINVAL;
+
+ md = mmc_blk_get(dev_to_disk(dev));
+ mmc_reinit_bounce_queue(&md->queue, md->queue.card, bouncesz);
+ mmc_blk_put(md);
+ return mmc_queue_bouncesz;
+}
+#endif
+
static int mmc_blk_probe(struct mmc_card *card)
{
struct mmc_blk_data *md, *part_md;
@@ -1648,6 +1680,18 @@ static int mmc_blk_probe(struct mmc_card *card)
if (mmc_add_disk(part_md))
goto out;
}
+
+#ifdef CONFIG_MMC_BLOCK_BOUNCE
+ md->bouncesz.show = mmc_bouncesz_show;
+ md->bouncesz.store = mmc_bouncesz_store;
+ sysfs_attr_init(&md->bouncesz.attr);
+ md->bouncesz.attr.name = "bouncesz";
+ md->bouncesz.attr.mode = S_IRUGO | S_IWUSR;
+ err = device_create_file(disk_to_dev(md->disk), &md->bouncesz);
+ if (err)
+ goto out;
+#endif
+
return 0;
out:
--
1.6.4
--
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