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r: 219032
b: refs/heads/master
c: 5e71b7a
h: refs/heads/master
v: v3
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Olof Johansson authored and Chris Ball committed Oct 25, 2010
1 parent 3332acd commit 1110806
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Showing 4 changed files with 55 additions and 13 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 061c6c847eeb11743e489a16e907b41c6f9042b6
refs/heads/master: 5e71b7a64cb4c6cff75ca42b535d8227526ec592
6 changes: 6 additions & 0 deletions trunk/Documentation/devices.txt
Original file line number Diff line number Diff line change
Expand Up @@ -2520,6 +2520,12 @@ Your cooperation is appreciated.
8 = /dev/mmcblk1 Second SD/MMC card
...

The start of next SD/MMC card can be configured with
CONFIG_MMC_BLOCK_MINORS, or overridden at boot/modprobe
time using the mmcblk.perdev_minors option. That would
bump the offset between each card to be the configured
value instead of the default 8.

179 char CCube DVXChip-based PCI products
0 = /dev/dvxirq0 First DVX device
1 = /dev/dvxirq1 Second DVX device
Expand Down
17 changes: 17 additions & 0 deletions trunk/drivers/mmc/card/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down
43 changes: 31 additions & 12 deletions trunk/drivers/mmc/card/block.c
Original file line number Diff line number Diff line change
Expand Up @@ -43,15 +43,27 @@
#include "queue.h"

MODULE_ALIAS("mmc:block");
#ifdef MODULE_PARAM_PREFIX
#undef MODULE_PARAM_PREFIX
#endif
#define MODULE_PARAM_PREFIX "mmcblk."

static DEFINE_MUTEX(block_mutex);

/*
* max 8 partitions per card
* The defaults come from config options but can be overriden by module
* or bootarg options.
*/
#define MMC_SHIFT 3
#define MMC_NUM_MINORS (256 >> MMC_SHIFT)
static int perdev_minors = CONFIG_MMC_BLOCK_MINORS;

static DEFINE_MUTEX(block_mutex);
static DECLARE_BITMAP(dev_use, MMC_NUM_MINORS);
/*
* We've only got one major, so number of mmcblk devices is
* limited to 256 / number of minors per device.
*/
static int max_devices;

/* 256 minors, so at most 256 separate devices */
static DECLARE_BITMAP(dev_use, 256);

/*
* There is one mmc_blk_data per slot.
Expand All @@ -67,6 +79,9 @@ struct mmc_blk_data {

static DEFINE_MUTEX(open_lock);

module_param(perdev_minors, int, 0444);
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;
Expand All @@ -88,10 +103,10 @@ 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);

Expand Down Expand Up @@ -566,8 +581,8 @@ 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);

Expand All @@ -584,7 +599,7 @@ 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;
Expand All @@ -601,7 +616,7 @@ 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;
Expand Down Expand Up @@ -670,7 +685,6 @@ static int mmc_blk_probe(struct mmc_card *card)
{
struct mmc_blk_data *md;
int err;

char cap_str[10];

/*
Expand Down Expand Up @@ -760,6 +774,11 @@ 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 = 256 / perdev_minors;

res = register_blkdev(MMC_BLOCK_MAJOR, "mmc");
if (res)
goto out;
Expand Down

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