linux-toradex.git/arch/m68k/kernel/process.c, branch v3.4.22

m68k: Add missing RCU idle APIs on idle loop

2012-10-12T20:38:54+00:00

commit 5b57ba37e82a15f345a6a2eb8c01a2b2d94c5eeb upstream.

In the old times, the whole idle task was considered
as an RCU quiescent state. But as RCU became more and
more successful overtime, some RCU read side critical
section have been added even in the code of some
architectures idle tasks, for tracing for example.

So nowadays, rcu_idle_enter() and rcu_idle_exit() must
be called by the architecture to tell RCU about the part
in the idle loop that doesn't make use of rcu read side
critical sections, typically the part that puts the CPU
in low power mode.

This is necessary for RCU to find the quiescent states in
idle in order to complete grace periods.

Add this missing pair of calls in the m68k's idle loop.

Reported-by: Paul E. McKenney 
Signed-off-by: Frederic Weisbecker 
Acked-by: Geert Uytterhoeven 
Cc: m68k 
Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett 
Signed-off-by: Greg Kroah-Hartman

Disintegrate asm/system.h for M68K

2012-03-28T17:30:02+00:00

Disintegrate asm/system.h for M68K.

Signed-off-by: David Howells 
Acked-by: Greg Ungerer 
cc: linux-m68k@lists.linux-m68k.org

Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu

2012-03-22T01:17:51+00:00

Pull m68knommu arch updates from Greg Ungerer:
 "Includes a cleanup of the non-MMU linker script (it now almost
  exclusively uses the well defined linker script support macros and
  definitions).  Some more merging of MMU and non-MMU common files
  (specifically the arch process.c, ptrace and time.c).  And a big
  cleanup of the massively duplicated ColdFire device definition code.

  Overall we remove about 2000 lines of code, and end up with a single
  set of platform device definitions for the serial ports, ethernet
  ports and QSPI ports common in most ColdFire SoCs.

  I expect you will get a merge conflict on arch/m68k/kernel/process.c,
  in cpu_idle().  It should be relatively strait forward to fixup."

And cpu_idle() conflict resolution was indeed trivial (merging the
nommu/mmu versions of process.c trivially conflicting with the
conversion to use the schedule_preempt_disabled() helper function)

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu: (57 commits)
  m68knommu: factor more common ColdFire cpu reset code
  m68knommu: make 528x CPU reset register addressing consistent
  m68knommu: make 527x CPU reset register addressing consistent
  m68knommu: make 523x CPU reset register addressing consistent
  m68knommu: factor some common ColdFire cpu reset code
  m68knommu: move old ColdFire timers init from CPU init to timers code
  m68knommu: clean up init code in ColdFire 532x startup
  m68knommu: clean up init code in ColdFire 528x startup
  m68knommu: clean up init code in ColdFire 523x startup
  m68knommu: merge common ColdFire QSPI platform setup code
  m68knommu: make 532x QSPI platform addressing consistent
  m68knommu: make 528x QSPI platform addressing consistent
  m68knommu: make 527x QSPI platform addressing consistent
  m68knommu: make 5249 QSPI platform addressing consistent
  m68knommu: make 523x QSPI platform addressing consistent
  m68knommu: make 520x QSPI platform addressing consistent
  m68knommu: merge common ColdFire FEC platform setup code
  m68knommu: make 532x FEC platform addressing consistent
  m68knommu: make 528x FEC platform addressing consistent
  m68knommu: make 527x FEC platform addressing consistent
  ...

m68k: merge the MMU and non-MMU versions of process.c

2012-03-04T23:43:05+00:00

The MMU and non-MMU varients of the m68k arch process.c code are pretty
much the same. Only a few minor details differ between the two. The
majority of the difference is to deal with having or wanting hardware FPU
support. So merge them back into a single process.c file.

Signed-off-by: Greg Ungerer 
Acked-by: Geert Uytterhoeven

m68k: merge m68k and m68knommu arch directories

2011-03-25T04:05:13+00:00

There is a lot of common code that could be shared between the m68k
and m68knommu arch branches. It makes sense to merge the two branches
into a single directory structure so that we can more easily share
that common code.

This is a brute force merge, based on a script from Stephen King
, which was originally written by Arnd Bergmann
.

> The script was inspired by the script Sam Ravnborg used to merge the
> includes from m68knommu. For those files common to both arches but
> differing in content, the m68k version of the file is renamed to
> _mm. and the m68knommu version of the file is moved into the
> corresponding m68k directory and renamed _no. and a small
> wrapper file . is used to select between the two version. Files
> that are common to both but don't differ are removed from the m68knommu
> tree and files and directories that are unique to the m68knommu tree are
> moved to the m68k tree. Finally, the arch/m68knommu tree is removed.
>
> To select between the the versions of the files, the wrapper uses
>
> #ifdef CONFIG_MMU
> #include _mm.
> #else
> #include _no.
> #endif

On top of this file merge I have done a simplistic merge of m68k and
m68knommu Kconfig, which primarily attempts to keep existing options and
menus in place. Other than a handful of options being moved it produces
identical .config outputs on m68k and m68knommu targets I tested it on.

With this in place there is now quite a bit of scope for merge cleanups
in future patches.

Signed-off-by: Greg Ungerer

BKL: remove extraneous #include

2010-11-17T16:59:32+00:00

The big kernel lock has been removed from all these files at some point,
leaving only the #include.

Remove this too as a cleanup.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Linus Torvalds

Make do_execve() take a const filename pointer

2010-08-18T01:07:43+00:00

Make do_execve() take a const filename pointer so that kernel_execve() compiles
correctly on ARM:

arch/arm/kernel/sys_arm.c:88: warning: passing argument 1 of 'do_execve' discards qualifiers from pointer target type

This also requires the argv and envp arguments to be consted twice, once for
the pointer array and once for the strings the array points to.  This is
because do_execve() passes a pointer to the filename (now const) to
copy_strings_kernel().  A simpler alternative would be to cast the filename
pointer in do_execve() when it's passed to copy_strings_kernel().

do_execve() may not change any of the strings it is passed as part of the argv
or envp lists as they are some of them in .rodata, so marking these strings as
const should be fine.

Further kernel_execve() and sys_execve() need to be changed to match.

This has been test built on x86_64, frv, arm and mips.

Signed-off-by: David Howells 
Tested-by: Ralf Baechle 
Acked-by: Russell King 
Signed-off-by: Linus Torvalds

Mark arguments to certain syscalls as being const

2010-08-13T23:53:13+00:00

Mark arguments to certain system calls as being const where they should be but
aren't.  The list includes:

 (*) The filename arguments of various stat syscalls, execve(), various utimes
     syscalls and some mount syscalls.

 (*) The filename arguments of some syscall helpers relating to the above.

 (*) The buffer argument of various write syscalls.

Signed-off-by: David Howells 
Acked-by: David S. Miller 
Signed-off-by: Linus Torvalds

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

2010-03-30T13:02:32+00:00

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: Tejun Heo 
Guess-its-ok-by: Christoph Lameter 
Cc: Ingo Molnar 
Cc: Lee Schermerhorn

m68k: Add NPTL support

2010-02-27T17:31:19+00:00

This patch adds several syscalls, that provide necessary
functionality to support NPTL on m68k/ColdFire.
The syscalls are get_thread_area, set_thread_area, atomic_cmpxchg_32 and
atomic_barrier.
The cmpxchg syscall is required for ColdFire as it doesn't support 'cas'
instruction.

Also a ptrace call PTRACE_GET_THREAD_AREA is added to allow debugger to
inspect the TLS storage.

Signed-off-by: Maxim Kuvyrkov 
Signed-off-by: Geert Uytterhoeven