]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
asm-generic: architecture independent readq/writeq for 32bit environment
authorHitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Tue, 7 Feb 2012 02:45:33 +0000 (11:45 +0900)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 22 Feb 2012 00:47:28 +0000 (16:47 -0800)
commit797a796a13df6b84a4791e57306737059b5b2384
tree400d13deef98fdf3fc893e9e55f208c5716b8ba9
parent27e74da9800289e69ba907777df1e2085231eff7
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>
drivers/block/nvme.c
drivers/edac/i3200_edac.c
drivers/platform/x86/ibm_rtl.c
drivers/platform/x86/intel_ips.c
drivers/scsi/qla4xxx/ql4_nx.c
include/asm-generic/io-64-nonatomic-hi-lo.h [new file with mode: 0644]
include/asm-generic/io-64-nonatomic-lo-hi.h [new file with mode: 0644]