diff mbox series

[V2,1/2] mmc: block: Support Host to control FUA

Message ID 20221021073025.18831-2-wenchao.chen666@gmail.com
State New
Headers
Series mmc: block: Support Host to control FUA |

Commit Message

Wenchao Chen Oct. 21, 2022, 7:30 a.m. UTC 
  From: Wenchao Chen <wenchao.chen@unisoc.com>

This patch introduces host->fua_disable for MMC host controller.
The host can turn off FUA to improve performance.

Signed-off-by: Wenchao Chen <wenchao.chen@unisoc.com>
---
V1 -> V2
Address Chaitanyak's suggestions
Address Avri's suggestions
---
 drivers/mmc/core/block.c | 3 ++-
 include/linux/mmc/host.h | 3 +++
 2 files changed, 5 insertions(+), 1 deletion(-)

Comments

Wenchao Chen Oct. 21, 2022, 8:47 a.m. UTC | #1 
Avri Altman <Avri.Altman@wdc.com> 于2022年10月21日周五 15:53写道：
>
> > From: Wenchao Chen <wenchao.chen@unisoc.com>
> >
> > This patch introduces host->fua_disable for MMC host controller.
> > The host can turn off FUA to improve performance.
> >
> > Signed-off-by: Wenchao Chen <wenchao.chen@unisoc.com>
> > ---
> > V1 -> V2
> > Address Chaitanyak's suggestions
> > Address Avri's suggestions
> > ---
> >  drivers/mmc/core/block.c | 3 ++-
> >  include/linux/mmc/host.h | 3 +++
> >  2 files changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c index
> > 54cd009aee50..333e819e077a 100644
> > --- a/drivers/mmc/core/block.c
> > +++ b/drivers/mmc/core/block.c
> > @@ -2490,7 +2490,8 @@ static struct mmc_blk_data
> > *mmc_blk_alloc_req(struct mmc_card *card,
> >             ((card->ext_csd.rel_param & EXT_CSD_WR_REL_PARAM_EN) ||
> >              card->ext_csd.rel_sectors)) {
> >                 md->flags |= MMC_BLK_REL_WR;
> > -               fua_enabled = true;
> > +               if (!card->host->fua_disable)
> > +                       fua_enabled = true;
> >                 cache_enabled = true;
> >         }
> >         if (mmc_cache_enabled(card->host)) diff --git a/include/linux/mmc/host.h
> > b/include/linux/mmc/host.h index 8fdd3cf971a3..16a5bee3eeae 100644
> > --- a/include/linux/mmc/host.h
> > +++ b/include/linux/mmc/host.h
> > @@ -517,6 +517,9 @@ struct mmc_host {
> >         struct blk_crypto_profile crypto_profile;  #endif
> >
> > +       /* Host FUA support */
> > +       bool                    fua_disable;
> Why do you need to invent a LLD mechanism, when you already have a block api (QUEUE_FLAG_FUA) for that?
> Which is actually misleading, since /sys/block/mmcblk0/queue/fua will still reads 0.
>
> Thanks,
> Avri
>
Hi Avri
The code expands as follows:
static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
      struct device *parent,
      sector_t size,
      bool default_ro,
      const char *subname,
      int area_type,
      unsigned int part_type)
{
...
if (md->flags & MMC_BLK_CMD23 &&
    ((card->ext_csd.rel_param & EXT_CSD_WR_REL_PARAM_EN) ||
     card->ext_csd.rel_sectors)) {
md->flags |= MMC_BLK_REL_WR;
if (!card->host->fua_disable) <<<Allow chip manufacturers whether to use FUA.
fua_enabled = true;
cache_enabled = true;
}
if (mmc_cache_enabled(card->host))
cache_enabled  = true;

blk_queue_write_cache(md->queue.queue, cache_enabled, fua_enabled); <<<
...
}

void blk_queue_write_cache(struct request_queue *q, bool wc, bool fua)
{
if (wc)
blk_queue_flag_set(QUEUE_FLAG_WC, q);
else
blk_queue_flag_clear(QUEUE_FLAG_WC, q);
if (fua)
blk_queue_flag_set(QUEUE_FLAG_FUA, q);  <<<
else
blk_queue_flag_clear(QUEUE_FLAG_FUA, q);

wbt_set_write_cache(q, test_bit(QUEUE_FLAG_WC, &q->queue_flags));
}

Also, echo 0 > fua is forbidden regardless of permissions.
Do you have any better suggestions?

> > +
> >         /* Host Software Queue support */
> >         bool                    hsq_enabled;
> >
> > --
> > 2.17.1
>
diff mbox series

Patch

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index 54cd009aee50..333e819e077a 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -2490,7 +2490,8 @@  static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
 	    ((card->ext_csd.rel_param & EXT_CSD_WR_REL_PARAM_EN) ||
 	     card->ext_csd.rel_sectors)) {
 		md->flags |= MMC_BLK_REL_WR;
-		fua_enabled = true;
+		if (!card->host->fua_disable)
+			fua_enabled = true;
 		cache_enabled = true;
 	}
 	if (mmc_cache_enabled(card->host))
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 8fdd3cf971a3..16a5bee3eeae 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -517,6 +517,9 @@  struct mmc_host {
 	struct blk_crypto_profile crypto_profile;
 #endif
 
+	/* Host FUA support */
+	bool			fua_disable;
+
 	/* Host Software Queue support */
 	bool			hsq_enabled;