Re: [PATCH] mmc: add wp_grp_size node

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Il 01/11/23 16:49, Bo Ye ha scritto:
From: "lin.gui" <lin.gui@xxxxxxxxxxxx>

Detail:
Add node "wp_grp_size", corresponding to WP_GRP_SIZE
(write protect group size) of eMMC's CSD register.

Scenario:
The eMMC card can be set into write-protected mode to
prevent data from being accidentally modified or deleted.
Wp_grp_size (Write Protect Group Size) refers to an
attribute of the eMMC card, used to manage write protection,
and is the CSD register  [36:32] of the eMMC device.
Wp_grp_size (Write Protect Group Size) indicates how many
eMMC blocks are contained in each write protection group on the eMMC card.

Final rendered file:
"/sys/class/mmc_host/mmc0/mmc0:0001/wp_grp_size"

Signed-off-by: lin.gui <lin.gui@xxxxxxxxxxxx>
Change-Id: I73952dbde2db375ba918daadb3264380b7863096

The change-id tag means nothing upstream. Please remove.

Also, the recipients list doesn't look right. Please use scripts/get_maintainer.pl
to get the right recipients list, or your patch will be ignored.

---
  drivers/mmc/core/mmc.c   | 16 +++++++++++++++-
  include/linux/mmc/card.h |  2 ++
  2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 4a4bab9aa726..9b67e49a9e63 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -136,6 +136,17 @@ static void mmc_set_erase_size(struct mmc_card *card)
  	mmc_init_erase(card);
  }
+
+static void mmc_set_wp_grp_size(struct mmc_card *card)
+{
+	if (card->ext_csd.erase_group_def & 1)
+		card->wp_grp_size = card->ext_csd.hc_erase_size *
+			card->ext_csd.raw_hc_erase_gap_size;
+	else
+		card->wp_grp_size = card->csd.erase_size *
+			(card->csd.wp_grp_size + 1);
+}
+
  /*
   * Given a 128-bit response, decode to our card CSD structure.
   */
@@ -186,6 +197,7 @@ static int mmc_decode_csd(struct mmc_card *card)
  		b = UNSTUFF_BITS(resp, 37, 5);
  		csd->erase_size = (a + 1) * (b + 1);
  		csd->erase_size <<= csd->write_blkbits - 9;
+		csd->wp_grp_size = UNSTUFF_BITS(resp, 32, 5);
  	}
return 0;
@@ -791,6 +803,7 @@ MMC_DEV_ATTR(csd, "%08x%08x%08x%08x\n", card->raw_csd[0], card->raw_csd[1],
  MMC_DEV_ATTR(date, "%02d/%04d\n", card->cid.month, card->cid.year);
  MMC_DEV_ATTR(erase_size, "%u\n", card->erase_size << 9);
  MMC_DEV_ATTR(preferred_erase_size, "%u\n", card->pref_erase << 9);
+MMC_DEV_ATTR(wp_grp_size, "%u\n", card->wp_grp_size << 9);
  MMC_DEV_ATTR(ffu_capable, "%d\n", card->ext_csd.ffu_capable);
  MMC_DEV_ATTR(hwrev, "0x%x\n", card->cid.hwrev);
  MMC_DEV_ATTR(manfid, "0x%06x\n", card->cid.manfid);
@@ -851,6 +864,7 @@ static struct attribute *mmc_std_attrs[] = {
  	&dev_attr_date.attr,
  	&dev_attr_erase_size.attr,
  	&dev_attr_preferred_erase_size.attr,
+	&dev_attr_wp_grp_size.attr,
  	&dev_attr_fwrev.attr,
  	&dev_attr_ffu_capable.attr,
  	&dev_attr_hwrev.attr,
@@ -1759,7 +1773,7 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
  			mmc_set_erase_size(card);
  		}
  	}
-
+	mmc_set_wp_grp_size(card);
  	/*
  	 * Ensure eMMC user default partition is enabled
  	 */
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index daa2f40d9ce6..62873ecc52f1 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -32,6 +32,7 @@ struct mmc_csd {
  	unsigned int		r2w_factor;
  	unsigned int		max_dtr;
  	unsigned int		erase_size;		/* In sectors */
+	unsigned int		wp_grp_size;
  	unsigned int		read_blkbits;
  	unsigned int		write_blkbits;
  	unsigned int		capacity;
@@ -304,6 +305,7 @@ struct mmc_card {
  	unsigned int		eg_boundary;	/* don't cross erase-group boundaries */
  	unsigned int		erase_arg;	/* erase / trim / discard */
   	u8			erased_byte;	/* value of erased bytes */
+	unsigned int		wp_grp_size; /* write group size in sectors */

There should be a tabulation before the comment, not a space.

Regards,
Angelo




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