1. 22 2月, 2012 1 次提交
    • H
      asm-generic: architecture independent readq/writeq for 32bit environment · 797a796a
      Hitoshi Mitake 提交于
      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 dbee8a0a ("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: NHitoshi Mitake <h.mitake@gmail.com>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      797a796a
  2. 25 5月, 2011 1 次提交
  3. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo 提交于
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  4. 24 9月, 2009 1 次提交