From: Arnd Bergmann <arnd@arndb.de>
To: linux-scsi@vger.kernel.org
Cc: jbottomley@odin.com, martin.petersen@oracle.com,
nico@fluxnic.net, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH] scsi: use sector_div instead of do_div
Date: Fri, 20 Nov 2015 17:38:28 +0100 [thread overview]
Message-ID: <24882658.08y4bWL6tn@wuerfel> (raw)
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;
}
WARNING: multiple messages have this Message-ID (diff)
From: arnd@arndb.de (Arnd Bergmann)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] scsi: use sector_div instead of do_div
Date: Fri, 20 Nov 2015 17:38:28 +0100 [thread overview]
Message-ID: <24882658.08y4bWL6tn@wuerfel> (raw)
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;
}
next reply other threads:[~2015-11-20 16:39 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-20 16:38 Arnd Bergmann [this message]
2015-11-20 16:38 ` [PATCH] scsi: use sector_div instead of do_div Arnd Bergmann
2015-11-24 12:48 ` Johannes Thumshirn
2015-11-24 12:48 ` Johannes Thumshirn
2015-11-24 12:48 ` Johannes Thumshirn
2015-11-24 12:50 ` Sagi Grimberg
2015-11-24 12:50 ` Sagi Grimberg
2015-11-24 15:03 ` Hannes Reinecke
2015-11-24 15:03 ` Hannes Reinecke
2015-11-26 3:28 ` Martin K. Petersen
2015-11-26 3:28 ` Martin K. Petersen
2015-11-26 3:28 ` Martin K. Petersen
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