4 files changed, 101 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-devices-mmc b/Documentation/ABI/testing/sysfs-devices-mmc
new file mode 100644
index 00000000000..5a50ab65584
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-devices-mmc
@@ -0,0 +1,21 @@
+What:           /sys/devices/.../mmc_host/mmcX/mmcX:XXXX/enhanced_area_offset
+Date:           January 2011
+Contact:        Chuanxiao Dong <chuanxiao.dong@intel.com>
+Description:
+                Enhanced area is a new feature defined in eMMC4.4 standard.
+                eMMC4.4 or later card can support such feature. This kind of
+                area can help to improve the card performance. If the feature
+                is enabled, this attribute will indicate the start address of
+                enhanced data area. If not, this attribute will be -EINVAL.
+                Unit Byte. Format decimal.
+
+What:           /sys/devices/.../mmc_host/mmcX/mmcX:XXXX/enhanced_area_size
+Date:           January 2011
+Contact:        Chuanxiao Dong <chuanxiao.dong@intel.com>
+Description:
+                Enhanced area is a new feature defined in eMMC4.4 standard.
+                eMMC4.4 or later card can support such feature. This kind of
+                area can help to improve the card performance. If the feature
+                is enabled, this attribute will indicate the size of enhanced
+                data area. If not, this attribute will be -EINVAL.
+                Unit KByte. Format decimal.
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 16006ef153f..6396c5d98e8 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -302,6 +302,44 @@ static int mmc_read_ext_csd(struct mmc_card *card)
         }
 
         if (card->ext_csd.rev >= 4) {
+                /*
+                 * Enhanced area feature support -- check whether the eMMC
+                 * card has the Enhanced area enabled.  If so, export enhanced
+                 * area offset and size to user by adding sysfs interface.
+                 */
+                if ((ext_csd[EXT_CSD_PARTITION_SUPPORT] & 0x2) &&
+                                (ext_csd[EXT_CSD_PARTITION_ATTRIBUTE] & 0x1)) {
+                        u8 hc_erase_grp_sz =
+                                ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE];
+                        u8 hc_wp_grp_sz =
+                                ext_csd[EXT_CSD_HC_WP_GRP_SIZE];
+
+                        card->ext_csd.enhanced_area_en = 1;
+                        /*
+                         * calculate the enhanced data area offset, in bytes
+                         */
+                        card->ext_csd.enhanced_area_offset =
+                                (ext_csd[139] << 24) + (ext_csd[138] << 16) +
+                                (ext_csd[137] << 8) + ext_csd[136];
+                        if (mmc_card_blockaddr(card))
+                                card->ext_csd.enhanced_area_offset <<= 9;
+                        /*
+                         * calculate the enhanced data area size, in kilobytes
+                         */
+                        card->ext_csd.enhanced_area_size =
+                                (ext_csd[142] << 16) + (ext_csd[141] << 8) +
+                                ext_csd[140];
+                        card->ext_csd.enhanced_area_size *=
+                                (size_t)(hc_erase_grp_sz * hc_wp_grp_sz);
+                        card->ext_csd.enhanced_area_size <<= 9;
+                } else {
+                        /*
+                         * If the enhanced area is not enabled, disable these
+                         * device attributes.
+                         */
+                        card->ext_csd.enhanced_area_offset = -EINVAL;
+                        card->ext_csd.enhanced_area_size = -EINVAL;
+                }
                 card->ext_csd.sec_trim_mult =
                         ext_csd[EXT_CSD_SEC_TRIM_MULT];
                 card->ext_csd.sec_erase_mult =
@@ -336,6 +374,9 @@ MMC_DEV_ATTR(manfid, "0x%06x\n", card->cid.manfid);
 MMC_DEV_ATTR(name, "%s\n", card->cid.prod_name);
 MMC_DEV_ATTR(oemid, "0x%04x\n", card->cid.oemid);
 MMC_DEV_ATTR(serial, "0x%08x\n", card->cid.serial);
+MMC_DEV_ATTR(enhanced_area_offset, "%llu\n",
+                card->ext_csd.enhanced_area_offset);
+MMC_DEV_ATTR(enhanced_area_size, "%u\n", card->ext_csd.enhanced_area_size);
 
 static struct attribute *mmc_std_attrs[] = {
         &dev_attr_cid.attr,
@@ -349,6 +390,8 @@ static struct attribute *mmc_std_attrs[] = {
         &dev_attr_name.attr,
         &dev_attr_oemid.attr,
         &dev_attr_serial.attr,
+        &dev_attr_enhanced_area_offset.attr,
+        &dev_attr_enhanced_area_size.attr,
         NULL,
 };
 
@@ -484,6 +527,37 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
         }
 
         /*
+         * If enhanced_area_en is TRUE, host needs to enable ERASE_GRP_DEF
+         * bit.  This bit will be lost everytime after a reset or power off.
+         */
+        if (card->ext_csd.enhanced_area_en) {
+                err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+                                EXT_CSD_ERASE_GROUP_DEF, 1);
+
+                if (err && err != -EBADMSG)
+                        goto free_card;
+
+                if (err) {
+                        err = 0;
+                        /*
+                         * Just disable enhanced area off & sz
+                         * will try to enable ERASE_GROUP_DEF
+                         * during next time reinit
+                         */
+                        card->ext_csd.enhanced_area_offset = -EINVAL;
+                        card->ext_csd.enhanced_area_size = -EINVAL;
+                } else {
+                        card->ext_csd.erase_group_def = 1;
+                        /*
+                         * enable ERASE_GRP_DEF successfully.
+                         * This will affect the erase size, so
+                         * here need to reset erase size
+                         */
+                        mmc_set_erase_size(card);
+                }
+        }
+
+        /*
          * Activate high speed (if supported)
          */
         if ((card->ext_csd.hs_max_dtr != 0) &&
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 8ce082781cc..4652cf9c544 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -54,6 +54,9 @@ struct mmc_ext_csd {
         unsigned int            sec_trim_mult;  /* Secure trim multiplier  */
         unsigned int            sec_erase_mult; /* Secure erase multiplier */
         unsigned int            trim_timeout;           /* In milliseconds */
+        bool                    enhanced_area_en;       /* enable bit */
+        unsigned long long      enhanced_area_offset;   /* Units: Byte */
+        unsigned int            enhanced_area_size;     /* Units: KB */
 };
 
 struct sd_scr {
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index 612301f85d1..264ba5451e3 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -253,6 +253,8 @@ struct _mmc_csd {
  * EXT_CSD fields
  */
 
+#define EXT_CSD_PARTITION_ATTRIBUTE     156     /* R/W */
+#define EXT_CSD_PARTITION_SUPPORT       160     /* RO */
 #define EXT_CSD_ERASE_GROUP_DEF         175     /* R/W */
 #define EXT_CSD_ERASED_MEM_CONT         181     /* RO */
 #define EXT_CSD_BUS_WIDTH               183     /* R/W */
@@ -262,6 +264,7 @@ struct _mmc_csd {
 #define EXT_CSD_CARD_TYPE               196     /* RO */
 #define EXT_CSD_SEC_CNT                 212     /* RO, 4 bytes */
 #define EXT_CSD_S_A_TIMEOUT             217     /* RO */
+#define EXT_CSD_HC_WP_GRP_SIZE          221     /* RO */
 #define EXT_CSD_ERASE_TIMEOUT_MULT      223     /* RO */
 #define EXT_CSD_HC_ERASE_GRP_SIZE       224     /* RO */
 #define EXT_CSD_SEC_TRIM_MULT           229     /* RO */