mmc: core: expose info about enhanced rpmb support

Following eMMC JEDEC JESD84-B51 standard, an enhanced form of
rpmb is supported. What this enhanced mode supports is in addition
to be able to write one rpmb or two rpmb frames at a time,
32 frames can be written at a time.

Expose this information present in ext csd field so that the
user space application that wants to make use of this can do so.
Signed-off-by: Krishna Konda <kkonda@codeaurora.org>
Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
Link: https://lore.kernel.org/r/1588341189-4371-1-git-send-email-vbadigan@codeaurora.orgSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/core/mmc.c

@@ -647,6 +647,9 @@ static int mmc_decode_ext_csd(struct mmc_card *card, u8 *ext_csd)
 				 mmc_hostname(card->host),
 				 card->ext_csd.cmdq_depth);
 		}
+		card->ext_csd.enhanced_rpmb_supported =
+					(card->ext_csd.rel_param &
+					 EXT_CSD_WR_REL_PARAM_EN_RPMB_REL_WR);
 	}
 out:
 	return err;
@@ -786,6 +789,8 @@ 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);
 MMC_DEV_ATTR(raw_rpmb_size_mult, "%#x\n", card->ext_csd.raw_rpmb_size_mult);
+MMC_DEV_ATTR(enhanced_rpmb_supported, "%#x\n",
+	card->ext_csd.enhanced_rpmb_supported);
 MMC_DEV_ATTR(rel_sectors, "%#x\n", card->ext_csd.rel_sectors);
 MMC_DEV_ATTR(ocr, "0x%08x\n", card->ocr);
 MMC_DEV_ATTR(rca, "0x%04x\n", card->rca);
@@ -843,6 +848,7 @@ static struct attribute *mmc_std_attrs[] = {
 	&dev_attr_enhanced_area_offset.attr,
 	&dev_attr_enhanced_area_size.attr,
 	&dev_attr_raw_rpmb_size_mult.attr,
+	&dev_attr_enhanced_rpmb_supported.attr,
 	&dev_attr_rel_sectors.attr,
 	&dev_attr_ocr.attr,
 	&dev_attr_rca.attr,

include/linux/mmc/card.h

@@ -48,6 +48,7 @@ struct mmc_ext_csd {
 	u8			sec_feature_support;
 	u8			rel_sectors;
 	u8			rel_param;
+	bool			enhanced_rpmb_supported;
 	u8			part_config;
 	u8			cache_ctrl;
 	u8			rst_n_function;

include/linux/mmc/mmc.h

@@ -325,6 +325,7 @@ static inline bool mmc_ready_for_data(u32 status)
  */
 
 #define EXT_CSD_WR_REL_PARAM_EN		(1<<2)
+#define EXT_CSD_WR_REL_PARAM_EN_RPMB_REL_WR	(1<<4)
 
 #define EXT_CSD_BOOT_WP_B_PWR_WP_DIS	(0x40)
 #define EXT_CSD_BOOT_WP_B_PERM_WP_DIS	(0x10)