Re: [PATCH v10] mmc : general purpose partition support.
From: Adrian Hunter
Date: Wed Oct 05 2011 - 07:37:17 EST
On 05/10/11 14:22, NamJae Jeon wrote:
2011/10/5 NamJae Jeon<linkinjeon@xxxxxxxxx>:
2011/10/5 Adrian Hunter<adrian.hunter@xxxxxxxxx>:
On 05/10/11 13:21, NamJae Jeon wrote:
2011/10/5 Adrian Hunter<adrian.hunter@xxxxxxxxx>:
On 04/10/11 20:45, Namjae Jeon wrote:
It allows gerneral purpose partitions in MMC Device.
And I try to simpliy make mmc_blk_alloc_parts using mmc_part structure
suggested by Andrei Warkentin.
After patching, we can see general purpose partitions like this.
cat /proc/partitions
179 0 847872 mmcblk0
179 192 4096 mmcblk0gp3
179 160 4096 mmcblk0gp2
179 128 4096 mmcblk0gp1
179 96 1052672 mmcblk0gp0
179 64 1024 mmcblk0boot1
179 32 1024 mmcblk0boot0
Signed-off-by: Namjae Jeon<linkinjeon@xxxxxxxxx>
---
drivers/mmc/card/block.c | 34 +++++++++++++++++------------
drivers/mmc/core/mmc.c | 52
++++++++++++++++++++++++++++++++++++++++++---
include/linux/mmc/card.h | 34 +++++++++++++++++++++++++++++-
include/linux/mmc/mmc.h | 5 +++-
4 files changed, 105 insertions(+), 20 deletions(-)
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 782d5f8..fb6f1e9 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -1470,26 +1470,32 @@ static int mmc_blk_alloc_part(struct mmc_card
*card,
return 0;
}
+/* MMC Physical partition consist of two boot partitions and
+ * up to four general purpose partitions.
+ * For each partitions enabled in EXT_CSD
+ * The block device will allocated to provide access to the partition.
+ */
+
static int mmc_blk_alloc_parts(struct mmc_card *card, struct
mmc_blk_data
*md)
{
- int ret = 0;
+ int idx, ret = 0;
if (!mmc_card_mmc(card))
return 0;
- if (card->ext_csd.boot_size&&
mmc_boot_partition_access(card->host)) {
- ret = mmc_blk_alloc_part(card, md,
EXT_CSD_PART_CONFIG_ACC_BOOT0,
- card->ext_csd.boot_size>> 9,
- true,
- "boot0");
- if (ret)
- return ret;
- ret = mmc_blk_alloc_part(card, md,
EXT_CSD_PART_CONFIG_ACC_BOOT1,
- card->ext_csd.boot_size>> 9,
- true,
- "boot1");
- if (ret)
- return ret;
+ for (idx = 0; idx< card->nr_parts; idx++) {
+ if ((idx == 0 || idx == 1)&&
+ !mmc_boot_partition_access(card->host))
+ continue;
Seems a bit fragile. What if someone decided to put the gp
partitions before the boot partitions. What about:
There are the default two boot partition in mmc spec. I think that
this case can not be happened.
And boot partition size of EXT CSD is read-only.
Can you explain which is case put to gp partitions before the boot
partition ?
Relying on the partition order in the partition array is fragile.
You cannot predict how someone may want to change it in the future,
and that person will not expect that certain positions have certain meaning.
0,1 of Boot partition is fixed if spec is not changed over. but gp
No. 0,1 are an accidental result of the order in which ext-csd is
parsed.
partition is variable in 2,3,4,5,6 of array.
If How someone change code, problem occur ?
If you move code around in mmc_read_ext_csd() the order can change,
hence it is fragile.
if (mmc_is_boot_partition(&part[idx])&&
!mmc_boot_partition_access(card->host)
continue;
And:
int mmc_is_boot_partition(struct mmc_part *part)
{
return part->part_cfg>= EXT_CSD_PART_CONFIG_ACC_BOOT0&&
part->part_cfg<= EXT_CSD_PART_CONFIG_ACC_BOOT0 +
MMC_NUM_BOOT_PARTITION;
}
+ if (card->part[idx].size) {
+ ret = mmc_blk_alloc_part(card, md,
+ card->part[idx].part_cfg,
+ card->part[idx].size>> 9,
+ card->part[idx].force_ro,
+ card->part[idx].name);
+ if (ret)
+ return ret;
+ }
}
return ret;
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index c632b1f..2f458a0 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -239,7 +239,9 @@ static int mmc_get_ext_csd(struct mmc_card *card, u8
**new_ext_csd)
*/
static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
{
- int err = 0;
+ int err = 0, idx;
+ unsigned int part_size;
+ u8 hc_erase_grp_sz = 0, hc_wp_grp_sz = 0;
BUG_ON(!card);
@@ -340,7 +342,14 @@ static int mmc_read_ext_csd(struct mmc_card *card,
u8
*ext_csd)
* There are two boot regions of equal size, defined in
* multiples of 128K.
*/
- card->ext_csd.boot_size = ext_csd[EXT_CSD_BOOT_MULT]<<
17;
+ if (ext_csd[EXT_CSD_BOOT_MULT]) {
+ for (idx = 0; idx< MMC_NUM_BOOT_PARTITION;
idx++)
{
+ part_size = ext_csd[EXT_CSD_BOOT_MULT]<<
17;
+ mmc_part_add(card, part_size,
+ EXT_CSD_PART_CONFIG_ACC_BOOT0 +
idx,
+ "boot%d", idx, true);
+ }
+ }
}
card->ext_csd.raw_hc_erase_gap_size =
@@ -362,9 +371,9 @@ static int mmc_read_ext_csd(struct mmc_card *card,
u8
*ext_csd)
card->ext_csd.raw_partition_support =
ext_csd[EXT_CSD_PARTITION_SUPPORT];
if ((ext_csd[EXT_CSD_PARTITION_SUPPORT]& 0x2)&&
(ext_csd[EXT_CSD_PARTITION_ATTRIBUTE]& 0x1)) {
- u8 hc_erase_grp_sz =
+ hc_erase_grp_sz =
ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE];
- u8 hc_wp_grp_sz =
+ hc_wp_grp_sz =
ext_csd[EXT_CSD_HC_WP_GRP_SIZE];
card->ext_csd.enhanced_area_en = 1;
@@ -393,6 +402,41 @@ static int mmc_read_ext_csd(struct mmc_card *card,
u8
*ext_csd)
card->ext_csd.enhanced_area_offset = -EINVAL;
card->ext_csd.enhanced_area_size = -EINVAL;
}
+
+ /*
+ * General purpose partition feature support --
+ * If ext_csd have the size of general purpose
partitions,
+ * set size, part_cfg, partition name in mmc_part.
+ */
+ if (ext_csd[EXT_CSD_PARTITION_SUPPORT]&
+ EXT_CSD_PART_SUPPORT_PART_EN) {
+ if (card->ext_csd.enhanced_area_en != 1) {
+ hc_erase_grp_sz =
+
ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE];
+ hc_wp_grp_sz =
+ ext_csd[EXT_CSD_HC_WP_GRP_SIZE];
+
+ card->ext_csd.enhanced_area_en = 1;
+ }
+
+ for (idx = 0; idx< MMC_NUM_GP_PARTITION;
idx++) {
+ if (!ext_csd[EXT_CSD_GP_SIZE_MULT + idx
*
3]&&
+ !ext_csd[EXT_CSD_GP_SIZE_MULT + idx * 3
+
1]&&
+ !ext_csd[EXT_CSD_GP_SIZE_MULT + idx * 3
+
2])
+ continue;
+ part_size =
+ (ext_csd[EXT_CSD_GP_SIZE_MULT + idx * 3
+
2]
+<< 16) +
+ (ext_csd[EXT_CSD_GP_SIZE_MULT + idx * 3
+
1]
+<< 8) +
+ ext_csd[EXT_CSD_GP_SIZE_MULT + idx * 3];
+ part_size *= (size_t)(hc_erase_grp_sz *
+ hc_wp_grp_sz);
+ mmc_part_add(card, part_size<< 19,
+ EXT_CSD_PART_CONFIG_ACC_GP0 +
idx,
+ "gp%d", idx, false);
+ }
+ }
card->ext_csd.sec_trim_mult =
ext_csd[EXT_CSD_SEC_TRIM_MULT];
card->ext_csd.sec_erase_mult =
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 5294ddf..0522627 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -12,6 +12,7 @@
#include<linux/mmc/core.h>
#include<linux/mod_devicetable.h>
+#include<linux/genhd.h>
struct mmc_cid {
unsigned int manfid;
@@ -64,7 +65,6 @@ struct mmc_ext_csd {
bool enhanced_area_en; /* enable bit */
unsigned long long enhanced_area_offset; /* Units: Byte */
unsigned int enhanced_area_size; /* Units: KB */
- unsigned int boot_size; /* in bytes */
u8 raw_partition_support; /* 160 */
u8 raw_erased_mem_count; /* 181 */
u8 raw_ext_csd_structure; /* 194 */
@@ -158,6 +158,23 @@ struct sdio_func_tuple;
#define SDIO_MAX_FUNCS 7
+/* The number of MMC physical partitions
+ * It consist of boot partitions(2), general purpose partitions(4) in
MMC
v4.4
+ */
+#define MMC_NUM_BOOT_PARTITION 2
+#define MMC_NUM_GP_PARTITION 4
+#define MMC_NUM_PHY_PARTITION 6
+
+/*
+ * MMC Physical partitions
+ */
+struct mmc_part {
+ unsigned int size; /* partition size (in bytes) */
+ unsigned int part_cfg; /* it used to part_type */
+ char name[DISK_NAME_LEN];
+ bool force_ro; /* to make boot parts RO by default */
+};
+
/*
* MMC device
*/
@@ -219,9 +236,24 @@ struct mmc_card {
unsigned int sd_bus_speed; /* Bus Speed Mode set for
the card */
struct dentry *debugfs_root;
+ struct mmc_part part[MMC_NUM_PHY_PARTITION]; /* physical
partitions */
+ unsigned int nr_parts;
};
/*
+ * This function fill contents in mmc_part.
+ */
+static inline void mmc_part_add(struct mmc_card *card, unsigned int
size,
+ unsigned int part_cfg, char *name, int idx, bool
ro)
+{
+ card->part[card->nr_parts].size = size;
+ card->part[card->nr_parts].part_cfg = part_cfg;
+ sprintf(card->part[card->nr_parts].name, name, idx);
+ card->part[card->nr_parts].force_ro = ro;
+ card->nr_parts++;
+}
+
+/*
* The world is not perfect and supplies us with broken mmc/sdio
devices.
* For at least some of these bugs we need a work-around.
*/
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index 50af227..ea558eb 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -270,6 +270,7 @@ struct _mmc_csd {
* EXT_CSD fields
*/
+#define EXT_CSD_GP_SIZE_MULT 143 /* R/W */
#define EXT_CSD_PARTITION_ATTRIBUTE 156 /* R/W */
#define EXT_CSD_PARTITION_SUPPORT 160 /* RO */
#define EXT_CSD_RST_N_FUNCTION 162 /* R/W */
@@ -313,7 +314,9 @@ struct _mmc_csd {
#define EXT_CSD_PART_CONFIG_ACC_MASK (0x7)
#define EXT_CSD_PART_CONFIG_ACC_BOOT0 (0x1)
-#define EXT_CSD_PART_CONFIG_ACC_BOOT1 (0x2)
+#define EXT_CSD_PART_CONFIG_ACC_GP0 (0x4)
+
+#define EXT_CSD_PART_SUPPORT_PART_EN (0x1)
#define EXT_CSD_CMD_SET_NORMAL (1<<0)
#define EXT_CSD_CMD_SET_SECURE (1<<1)
--
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