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Subject[PATCH v5 1/2] mmc: core: Factor out the alignment of erase size
Date
In order to clean up the mmc_erase() function and do some optimization
for erase size alignment, factor out the guts of erase size alignment
into mmc_align_erase_size() function.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Tested-by: Shawn Lin <shawn.lin@rock-chips.com>
---
Changes since v4:
- Abandon the patch removing the checking if mmc can erase.
- Add missing validations in mmc_erase().

Changes since v3:
- Split into 3 separate patches.
- Add test tag by Shawn.

Changes since v2:
- Add nr checking and other optimization in mmc_erase() function.

Changes since v1:
- Add the alignment if card->erase_size is not power of 2.
---
drivers/mmc/core/core.c | 48 +++++++++++++++++++++++++++++++----------------
1 file changed, 32 insertions(+), 16 deletions(-)

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index e55cde6..11b4897 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2202,6 +2202,36 @@ out:
return err;
}

+static unsigned int mmc_align_erase_size(struct mmc_card *card,
+ unsigned int *from,
+ unsigned int *to,
+ unsigned int nr)
+{
+ unsigned int from_new = *from, nr_new = nr, rem;
+
+ rem = from_new % card->erase_size;
+ if (rem) {
+ rem = card->erase_size - rem;
+ from_new += rem;
+ if (nr_new > rem)
+ nr_new -= rem;
+ else
+ return 0;
+ }
+
+ rem = nr_new % card->erase_size;
+ if (rem)
+ nr_new -= rem;
+
+ if (nr_new == 0)
+ return 0;
+
+ *to = from_new + nr_new;
+ *from = from_new;
+
+ return nr_new;
+}
+
/**
* mmc_erase - erase sectors.
* @card: card to erase
@@ -2240,26 +2270,12 @@ int mmc_erase(struct mmc_card *card, unsigned int from, unsigned int nr,
return -EINVAL;
}

- if (arg == MMC_ERASE_ARG) {
- rem = from % card->erase_size;
- if (rem) {
- rem = card->erase_size - rem;
- from += rem;
- if (nr > rem)
- nr -= rem;
- else
- return 0;
- }
- rem = nr % card->erase_size;
- if (rem)
- nr -= rem;
- }
+ if (arg == MMC_ERASE_ARG)
+ nr = mmc_align_erase_size(card, &from, &to, nr);

if (nr == 0)
return 0;

- to = from + nr;
-
if (to <= from)
return -EINVAL;

--
1.7.9.5
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