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| author | Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp> | 2012-02-07 11:45:33 +0900 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-02-21 16:47:28 -0800 |
| commit | 797a796a13df6b84a4791e57306737059b5b2384 (patch) | |
| tree | 400d13deef98fdf3fc893e9e55f208c5716b8ba9 /drivers/block | |
| parent | 27e74da9800289e69ba907777df1e2085231eff7 (diff) | |
| download | linux-797a796a13df6b84a4791e57306737059b5b2384.tar.bz2 | |
asm-generic: architecture independent readq/writeq for 32bit environment
This provides unified readq()/writeq() helper functions for 32-bit
drivers.
For some cases, readq/writeq without atomicity is harmful, and order of
io access has to be specified explicitly. So in this patch, new two
header files which contain non-atomic readq/writeq are added.
- <asm-generic/io-64-nonatomic-lo-hi.h> provides non-atomic readq/
writeq with the order of lower address -> higher address
- <asm-generic/io-64-nonatomic-hi-lo.h> provides non-atomic readq/
writeq with reversed order
This allows us to remove some readq()s that were added drivers when the
default non-atomic ones were removed in commit dbee8a0affd5 ("x86:
remove 32-bit versions of readq()/writeq()")
The drivers which need readq/writeq but can do with the non-atomic ones
must add the line:
#include <asm-generic/io-64-nonatomic-lo-hi.h> /* or hi-lo.h */
But this will be nop in 64-bit environments, and no other #ifdefs are
required. So I believe that this patch can solve the problem of
1. driver-specific readq/writeq
2. atomicity and order of io access
This patch is tested with building allyesconfig and allmodconfig as
ARCH=x86 and ARCH=i386 on top of tip/master.
Cc: Kashyap Desai <Kashyap.Desai@lsi.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Ravi Anand <ravi.anand@qlogic.com>
Cc: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Jason Uhlenkott <juhlenko@akamai.com>
Cc: James Bottomley <James.Bottomley@parallels.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Roland Dreier <roland@purestorage.com>
Cc: James Bottomley <jbottomley@parallels.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Hitoshi Mitake <h.mitake@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/nvme.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/block/nvme.c b/drivers/block/nvme.c index c1dc4d86c221..1f3c1a7d132a 100644 --- a/drivers/block/nvme.c +++ b/drivers/block/nvme.c @@ -41,6 +41,8 @@ #include <linux/types.h> #include <linux/version.h> +#include <asm-generic/io-64-nonatomic-lo-hi.h> + #define NVME_Q_DEPTH 1024 #define SQ_SIZE(depth) (depth * sizeof(struct nvme_command)) #define CQ_SIZE(depth) (depth * sizeof(struct nvme_completion)) |