linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: jthumshirn@suse.de (Johannes Thumshirn)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] scsi: use sector_div instead of do_div
Date: Tue, 24 Nov 2015 13:48:59 +0100	[thread overview]
Message-ID: <1448369339.2877.30.camel@suse.de> (raw)
In-Reply-To: <24882658.08y4bWL6tn@wuerfel>

On Fri, 2015-11-20 at 17:38 +0100, Arnd Bergmann wrote:
> do_div is the wrong way to divide a sector_t, as it is less
> efficient when sector_t is 32-bit wide. With the upcoming
> do_div optimizations, the kernel starts warning about this:
> 
> drivers/scsi/scsi_debug.c: In function 'dif_store':
> include/asm-generic/div64.h:207:28: warning: comparison of distinct
> pointer types lacks a cast
> 
> This changes the code to use sector_div instead, which always
> produces optimal code.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> Found on the ARM randconfig build today, after I merged Nico's
> patches
> for linux-next
> 
> diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
> index dfcc45bb03b1..ec622ba9864a 100644
> --- a/drivers/scsi/scsi_debug.c
> +++ b/drivers/scsi/scsi_debug.c
> @@ -678,7 +678,7 @@ static void *fake_store(unsigned long long lba)
> ?
> ?static struct sd_dif_tuple *dif_store(sector_t sector)
> ?{
> -	sector = do_div(sector, sdebug_store_sectors);
> +	sector = sector_div(sector, sdebug_store_sectors);
> ?
> ?	return dif_storep + sector;
> ?}
> @@ -2780,7 +2780,7 @@ static unsigned long lba_to_map_index(sector_t
> lba)
> ?		lba += scsi_debug_unmap_granularity -
> ?			scsi_debug_unmap_alignment;
> ?	}
> -	do_div(lba, scsi_debug_unmap_granularity);
> +	sector_div(lba, scsi_debug_unmap_granularity);
> ?
> ?	return lba;
> ?}
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-scsi" 
> in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at??http://vger.kernel.org/majordomo-info.html


Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>

  reply	other threads:[~2015-11-24 12:48 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-20 16:38 [PATCH] scsi: use sector_div instead of do_div Arnd Bergmann
2015-11-24 12:48 ` Johannes Thumshirn [this message]
2015-11-24 12:50 ` Sagi Grimberg
2015-11-24 15:03 ` Hannes Reinecke
2015-11-26  3:28 ` Martin K. Petersen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1448369339.2877.30.camel@suse.de \
    --to=jthumshirn@suse.de \
    --cc=linux-arm-kernel@lists.infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).