[PATCH v4 2/3] mmc: core: Factor out the alignment of erase size

[Baolin Wang]

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.w...@linaro.org>
Tested-by: Shawn Lin <shawn....@rock-chips.com>
---
 drivers/mmc/core/core.c |   60 +++++++++++++++++++++++++++++------------------
 1 file changed, 37 insertions(+), 23 deletions(-)

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 7d7209d..5f93eef 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2202,6 +2202,37 @@ 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;
+
+       /* 'from' and 'to' are inclusive */
+       *to = from_new + nr_new - 1;
+       *from = from_new;
+
+       return nr_new;
+}
+
 /**
  * mmc_erase - erase sectors.
  * @card: card to erase
@@ -2234,31 +2265,14 @@ int mmc_erase(struct mmc_card *card, unsigned int from, 
unsigned int nr,
        }
 
        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;
+               nr = mmc_align_erase_size(card, &from, &to, nr);
+               if (nr == 0)
+                       return 0;
+       } else {
+               /* 'from' and 'to' are inclusive */
+               to -= 1;
        }
 
-       if (nr == 0)
-               return 0;
-
-       to = from + nr;
-
-       if (to <= from)
-               return -EINVAL;
-
-       /* 'from' and 'to' are inclusive */
-       to -= 1;
-
        /*
         * Special case where only one erase-group fits in the timeout budget:
         * If the region crosses an erase-group boundary on this particular
-- 
1.7.9.5