@@ -14,6 +14,23 @@ config MMC_BLOCK
mount the filesystem. Almost everyone wishing MMC support
should say Y or M here.
+config MMC_BLOCK_MINORS
+ int "Number of minors per block device"
+ range 4 256
+ default 8
+ help
+ Number of minors per block device. One is needed for every
+ partition on the disk (plus one for the whole disk).
+
+ Number of total MMC minors available is 256, so your number
+ of supported block devices will be limited to 256 divided
+ by this number.
+
+ Default is 8 to be backwards compatible with previous
+ hardwired device numbering.
+
+ If unsure, say 8 here.
+
config MMC_BLOCK_BOUNCE
bool "Use bounce buffer for simple hosts"
depends on MMC_BLOCK
@@ -43,14 +43,26 @@
#include "queue.h"
MODULE_ALIAS("mmc:block");
+#ifdef MODULE_PARAM_PREFIX
+#undef MODULE_PARAM_PREFIX
+#endif
+#define MODULE_PARAM_PREFIX "mmcblk."
-/*
- * max 8 partitions per card
+
+/*
+ * The defaults come from config options but can be overriden by module
+ * or bootarg options.
+ */
+static int perdev_minors = CONFIG_MMC_BLOCK_MINORS;
+
+/*
+ * We've only got one major, so number of mmcblk devices is
+ * limited to 256 / number of minors per device.
*/
-#define MMC_SHIFT 3
-#define MMC_NUM_MINORS (256 >> MMC_SHIFT)
+static int max_devices = DIV_ROUND_UP(256, CONFIG_MMC_BLOCK_MINORS);
-static DECLARE_BITMAP(dev_use, MMC_NUM_MINORS);
+/* 256 minors, so at most 256 separate devices */
+static DECLARE_BITMAP(dev_use, 256);
/*
* There is one mmc_blk_data per slot.
@@ -66,6 +78,9 @@ struct mmc_blk_data {
static DEFINE_MUTEX(open_lock);
+module_param(perdev_minors, int, 0644);
+MODULE_PARM_DESC(perdev_minors, "Minors numbers to allocate per device");
+
static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
{
struct mmc_blk_data *md;
@@ -87,10 +102,10 @@ static void mmc_blk_put(struct mmc_blk_data *md)
md->usage--;
if (md->usage == 0) {
int devmaj = MAJOR(disk_devt(md->disk));
- int devidx = MINOR(disk_devt(md->disk)) >> MMC_SHIFT;
+ int devidx = MINOR(disk_devt(md->disk)) / perdev_minors;
if (!devmaj)
- devidx = md->disk->first_minor >> MMC_SHIFT;
+ devidx = md->disk->first_minor / perdev_minors;
blk_cleanup_queue(md->queue.queue);
@@ -482,8 +497,8 @@ static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
struct mmc_blk_data *md;
int devidx, ret;
- devidx = find_first_zero_bit(dev_use, MMC_NUM_MINORS);
- if (devidx >= MMC_NUM_MINORS)
+ devidx = find_first_zero_bit(dev_use, max_devices);
+ if (devidx >= max_devices)
return ERR_PTR(-ENOSPC);
__set_bit(devidx, dev_use);
@@ -500,7 +515,7 @@ static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
*/
md->read_only = mmc_blk_readonly(card);
- md->disk = alloc_disk(1 << MMC_SHIFT);
+ md->disk = alloc_disk(perdev_minors);
if (md->disk == NULL) {
ret = -ENOMEM;
goto err_kfree;
@@ -517,7 +532,7 @@ static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
md->queue.data = md;
md->disk->major = MMC_BLOCK_MAJOR;
- md->disk->first_minor = devidx << MMC_SHIFT;
+ md->disk->first_minor = devidx * perdev_minors;
md->disk->fops = &mmc_bdops;
md->disk->private_data = md;
md->disk->queue = md->queue.queue;
@@ -593,7 +608,6 @@ static int mmc_blk_probe(struct mmc_card *card)
{
struct mmc_blk_data *md;
int err;
-
char cap_str[10];
/*
@@ -683,6 +697,11 @@ static int __init mmc_blk_init(void)
{
int res;
+ if (perdev_minors != CONFIG_MMC_BLOCK_MINORS) {
+ pr_info("mmcblk: using %d minors per device\n", perdev_minors);
+ max_devices = DIV_ROUND_UP(256, perdev_minors);
+ }
+
res = register_blkdev(MMC_BLOCK_MAJOR, "mmc");
if (res)
goto out;