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* [PATCH v5 1/2] mmc: core: Factor out the alignment of erase size
@ 2016-09-07  2:38 Baolin Wang
  2016-09-07  2:38 ` [PATCH v5 2/2] mmc: core: Optimize the mmc erase size alignment Baolin Wang
  2016-09-09  9:46 ` [PATCH v5 1/2] mmc: core: Factor out the alignment of erase size Ulf Hansson
  0 siblings, 2 replies; 4+ messages in thread
From: Baolin Wang @ 2016-09-07  2:38 UTC (permalink / raw)
  To: ulf.hansson
  Cc: adrian.hunter, rmk+kernel, shawn.lin, dianders, heiko, david,
	hdegoede, linux-mmc, linux-kernel, broonie, linus.walleij,
	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.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

^ permalink raw reply related	[flat|nested] 4+ messages in thread
* [PATCH v5 2/2] mmc: core: Optimize the mmc erase size alignment
  2016-09-07  2:38 [PATCH v5 1/2] mmc: core: Factor out the alignment of erase size Baolin Wang
@ 2016-09-07  2:38 ` Baolin Wang
  2016-09-09  9:46   ` Ulf Hansson
  2016-09-09  9:46 ` [PATCH v5 1/2] mmc: core: Factor out the alignment of erase size Ulf Hansson
  1 sibling, 1 reply; 4+ messages in thread
From: Baolin Wang @ 2016-09-07  2:38 UTC (permalink / raw)
  To: ulf.hansson
  Cc: adrian.hunter, rmk+kernel, shawn.lin, dianders, heiko, david,
	hdegoede, linux-mmc, linux-kernel, broonie, linus.walleij,
	baolin.wang

In most cases the 'card->erase_size' is power of 2, then the round_up/down()
function is more efficient than '%' operation when the 'card->erase_size' is
power of 2.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Tested-by: Shawn Lin <shawn.lin@rock-chips.com>
---
 drivers/mmc/core/core.c |   34 ++++++++++++++++++++++++++--------
 1 file changed, 26 insertions(+), 8 deletions(-)

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 11b4897..4264ac6 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2209,19 +2209,37 @@ static unsigned int mmc_align_erase_size(struct mmc_card *card,
 {
 	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;
+	/*
+	 * When the 'card->erase_size' is power of 2, we can use round_up/down()
+	 * to align the erase size efficiently.
+	 */
+	if (is_power_of_2(card->erase_size)) {
+		unsigned int temp = from_new;
+
+		from_new = round_up(temp, card->erase_size);
+		rem = from_new - temp;
+
 		if (nr_new > rem)
 			nr_new -= rem;
 		else
 			return 0;
-	}
 
-	rem = nr_new % card->erase_size;
-	if (rem)
-		nr_new -= rem;
+		nr_new = round_down(nr_new, card->erase_size);
+	} else {
+		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;
-- 
1.7.9.5

^ permalink raw reply related	[flat|nested] 4+ messages in thread
* Re: [PATCH v5 1/2] mmc: core: Factor out the alignment of erase size
  2016-09-07  2:38 [PATCH v5 1/2] mmc: core: Factor out the alignment of erase size Baolin Wang
  2016-09-07  2:38 ` [PATCH v5 2/2] mmc: core: Optimize the mmc erase size alignment Baolin Wang
@ 2016-09-09  9:46 ` Ulf Hansson
  1 sibling, 0 replies; 4+ messages in thread
From: Ulf Hansson @ 2016-09-09  9:46 UTC (permalink / raw)
  To: Baolin Wang
  Cc: Adrian Hunter, Russell King, Shawn Lin, Doug Anderson,
	Heiko Stübner, David Jander, Hans de Goede, linux-mmc,
	linux-kernel, Mark Brown, Linus Walleij

On 7 September 2016 at 04:38, Baolin Wang <baolin.wang@linaro.org> wrote:
> 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>

Thanks, applied for next!

Kind regards
Uffe

> ---
> 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
>

^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: [PATCH v5 2/2] mmc: core: Optimize the mmc erase size alignment
  2016-09-07  2:38 ` [PATCH v5 2/2] mmc: core: Optimize the mmc erase size alignment Baolin Wang
@ 2016-09-09  9:46   ` Ulf Hansson
  0 siblings, 0 replies; 4+ messages in thread
From: Ulf Hansson @ 2016-09-09  9:46 UTC (permalink / raw)
  To: Baolin Wang
  Cc: Adrian Hunter, Russell King, Shawn Lin, Doug Anderson,
	Heiko Stübner, David Jander, Hans de Goede, linux-mmc,
	linux-kernel, Mark Brown, Linus Walleij

On 7 September 2016 at 04:38, Baolin Wang <baolin.wang@linaro.org> wrote:
> In most cases the 'card->erase_size' is power of 2, then the round_up/down()
> function is more efficient than '%' operation when the 'card->erase_size' is
> power of 2.
>
> Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
> Tested-by: Shawn Lin <shawn.lin@rock-chips.com>

Thanks, applied for next!

Kind regards
Uffe

> ---
>  drivers/mmc/core/core.c |   34 ++++++++++++++++++++++++++--------
>  1 file changed, 26 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index 11b4897..4264ac6 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -2209,19 +2209,37 @@ static unsigned int mmc_align_erase_size(struct mmc_card *card,
>  {
>         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;
> +       /*
> +        * When the 'card->erase_size' is power of 2, we can use round_up/down()
> +        * to align the erase size efficiently.
> +        */
> +       if (is_power_of_2(card->erase_size)) {
> +               unsigned int temp = from_new;
> +
> +               from_new = round_up(temp, card->erase_size);
> +               rem = from_new - temp;
> +
>                 if (nr_new > rem)
>                         nr_new -= rem;
>                 else
>                         return 0;
> -       }
>
> -       rem = nr_new % card->erase_size;
> -       if (rem)
> -               nr_new -= rem;
> +               nr_new = round_down(nr_new, card->erase_size);
> +       } else {
> +               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;
> --
> 1.7.9.5
>

^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2016-09-09  9:46 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-09-07  2:38 [PATCH v5 1/2] mmc: core: Factor out the alignment of erase size Baolin Wang
2016-09-07  2:38 ` [PATCH v5 2/2] mmc: core: Optimize the mmc erase size alignment Baolin Wang
2016-09-09  9:46   ` Ulf Hansson
2016-09-09  9:46 ` [PATCH v5 1/2] mmc: core: Factor out the alignment of erase size Ulf Hansson

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