linux-toradex.git/include/asm-frv, branch v2.6.25-rc2

Fix FRV cmpxchg_local

2008-02-08T23:33:32+00:00

Fix the FRV cmpxchg_local by breaking the following header dependency loop :

linux/kernel.h -> linux/bitops.h -> asm-frv/bitops.h -> asm-frv/atomic.h
  -> asm-frv/system.h ->
  asm-generic/cmpxchg_local.h -> typecheck() defined in linux/kernel.h

and

linux/kernel.h -> linux/bitops.h -> asm-frv/bitops.h -> asm-frv/atomic.h ->
  asm-generic/cmpxchg_local.h -> typecheck() defined in linux/kernel.h

In order to fix this :
- Move the atomic_test_and_ *_mask inlines from asm-frv/atomic.h (why are they
  there at all anyway ? They are not touching atomic_t variables!) to
  asm-frv/bitops.h.

Also fix a build issue with cmpxchg : it does not cast to (unsigned long *)
like other architectures, to deal with it in the cmpxchg_local macro.

FRV builds fine with this patch.

Thanks to Adrian Bunk  for spotting this bug.

Signed-off-by: Mathieu Desnoyers 
Cc: Adrian Bunk 
Cc: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

CONFIG_HIGHPTE vs. sub-page page tables.

2008-02-08T17:22:42+00:00

Background: I've implemented 1K/2K page tables for s390.  These sub-page
page tables are required to properly support the s390 virtualization
instruction with KVM.  The SIE instruction requires that the page tables
have 256 page table entries (pte) followed by 256 page status table entries
(pgste).  The pgstes are only required if the process is using the SIE
instruction.  The pgstes are updated by the hardware and by the hypervisor
for a number of reasons, one of them is dirty and reference bit tracking.
To avoid wasting memory the standard pte table allocation should return
1K/2K (31/64 bit) and 2K/4K if the process is using SIE.

Problem: Page size on s390 is 4K, page table size is 1K or 2K.  That means
the s390 version for pte_alloc_one cannot return a pointer to a struct
page.  Trouble is that with the CONFIG_HIGHPTE feature on x86 pte_alloc_one
cannot return a pointer to a pte either, since that would require more than
32 bit for the return value of pte_alloc_one (and the pte * would not be
accessible since its not kmapped).

Solution: The only solution I found to this dilemma is a new typedef: a
pgtable_t.  For s390 pgtable_t will be a (pte *) - to be introduced with a
later patch.  For everybody else it will be a (struct page *).  The
additional problem with the initialization of the ptl lock and the
NR_PAGETABLE accounting is solved with a constructor pgtable_page_ctor and
a destructor pgtable_page_dtor.  The page table allocation and free
functions need to call these two whenever a page table page is allocated or
freed.  pmd_populate will get a pgtable_t instead of a struct page pointer.
 To get the pgtable_t back from a pmd entry that has been installed with
pmd_populate a new function pmd_pgtable is added.  It replaces the pmd_page
call in free_pte_range and apply_to_pte_range.

Signed-off-by: Martin Schwidefsky 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

avoid overflows in kernel/time.c

2008-02-08T17:22:39+00:00

When the conversion factor between jiffies and milli- or microseconds is
not a single multiply or divide, as for the case of HZ == 300, we currently
do a multiply followed by a divide.  The intervening result, however, is
subject to overflows, especially since the fraction is not simplified (for
HZ == 300, we multiply by 300 and divide by 1000).

This is exposed to the user when passing a large timeout to poll(), for
example.

This patch replaces the multiply-divide with a reciprocal multiplication on
32-bit platforms.  When the input is an unsigned long, there is no portable
way to do this on 64-bit platforms there is no portable way to do this
since it requires a 128-bit intermediate result (which gcc does support on
64-bit platforms but may generate libgcc calls, e.g.  on 64-bit s390), but
since the output is a 32-bit integer in the cases affected, just simplify
the multiply-divide (*3/10 instead of *300/1000).

The reciprocal multiply used can have off-by-one errors in the upper half
of the valid output range.  This could be avoided at the expense of having
to deal with a potential 65-bit intermediate result.  Since the intent is
to avoid overflow problems and most of the other time conversions are only
semiexact, the off-by-one errors were considered an acceptable tradeoff.

At Ralf Baechle's suggestion, this version uses a Perl script to compute
the necessary constants.  We already have dependencies on Perl for kernel
compiles.  This does, however, require the Perl module Math::BigInt, which
is included in the standard Perl distribution starting with version 5.8.0.
In order to support older versions of Perl, include a table of canned
constants in the script itself, and structure the script so that
Math::BigInt isn't required if pulling values from said table.

Running the script requires that the HZ value is available from the
Makefile.  Thus, this patch also adds the Kconfig variable CONFIG_HZ to the
architectures which didn't already have it (alpha, cris, frv, h8300, m32r,
m68k, m68knommu, sparc, v850, and xtensa.) It does *not* touch the sh or
sh64 architectures, since Paul Mundt has dealt with those separately in the
sh tree.

Signed-off-by: H. Peter Anvin 
Cc: Ralf Baechle ,
Cc: Sam Ravnborg ,
Cc: Paul Mundt ,
Cc: Richard Henderson ,
Cc: Michael Starvik ,
Cc: David Howells ,
Cc: Yoshinori Sato ,
Cc: Hirokazu Takata ,
Cc: Geert Uytterhoeven ,
Cc: Roman Zippel ,
Cc: William L. Irwin ,
Cc: Chris Zankel ,
Cc: H. Peter Anvin ,
Cc: Jan Engelhardt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

asm-*/posix_types.h: scrub GLIBC

2008-02-08T17:22:34+00:00

Some arches (like alpha and ia64) already have a clean posix_types.h header.
This brings all the others in line by removing all references to __GLIBC__
(and some undocumented __USE_ALL).

Signed-off-by: Mike Frysinger 
Acked-by: Ingo Molnar 
Cc: Ulrich Drepper 
Cc: Roland McGrath 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

aout: suppress A.OUT library support if !CONFIG_ARCH_SUPPORTS_AOUT

2008-02-08T17:22:30+00:00

Suppress A.OUT library support if CONFIG_ARCH_SUPPORTS_AOUT is not set.

Not all architectures support the A.OUT binfmt, so the ELF binfmt should not
be permitted to go looking for A.OUT libraries to load in such a case.  Not
only that, but under such conditions A.OUT core dumps are not produced either.

To make this work, this patch also does the following:

 (1) Makes the existence of the contents of linux/a.out.h contingent on
     CONFIG_ARCH_SUPPORTS_AOUT.

 (2) Renames dump_thread() to aout_dump_thread() as it's only called by A.OUT
     core dumping code.

 (3) Moves aout_dump_thread() into asm/a.out-core.h and makes it inline.  This
     is then included only where needed.  This means that this bit of arch
     code will be stored in the appropriate A.OUT binfmt module rather than
     the core kernel.

 (4) Drops A.OUT support for Blackfin (according to Mike Frysinger it's not
     needed) and FRV.

This patch depends on the previous patch to move STACK_TOP[_MAX] out of
asm/a.out.h and into asm/processor.h as they're required whether or not A.OUT
format is available.

[jdike@addtoit.com: uml: re-remove accidentally restored code]
Signed-off-by: David Howells 
Cc: 
Signed-off-by: Jeff Dike 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Add cmpxchg_local to frv

2008-02-07T16:42:32+00:00

Use the new generic cmpxchg_local (disables interrupt) for 8, 16 and 64 bits
arguments. Use the 32 bits cmpxchg available on the architecture for 32 bits
arguments.

Signed-off-by: Mathieu Desnoyers 
Cc: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Unexport asm/page.h

2008-02-07T16:42:30+00:00

Do not export asm/page.h during make headers_install.  This removes PAGE_SIZE
from userspace headers.

Signed-off-by: Kirill A. Shutemov 
Reviewed-by: David Woodhouse 
Cc: David Howells 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: H. Peter Anvin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Cleanup asm/{elf,page,user}.h: #ifdef KERNEL is no longer needed

2008-02-07T16:42:30+00:00

asm/elf.h, asm/page.h and asm/user.h don't export to userspace now, so we can
drop #ifdef __KERNEL__ for them.

[k.shutemov@gmail.com: remove #ifdef __KERNEL_]
Signed-off-by: Kirill A. Shutemov 
Reviewed-by: David Woodhouse 
Cc: 
Signed-off-by: Kirill A. Shutemov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

timerfd: fix remaining architectures

2008-02-05T22:37:15+00:00

Cc: David Howells 
Cc: Hirokazu Takata 
Cc: Paul Mundt 
Cc: Kazumoto Kojima 
Cc: Richard Curnow 
Cc: Davide Libenzi 
Cc: Michael Kerrisk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

frv: remove dead config symbol from FRV code

2008-02-05T17:44:20+00:00

Remove dead config symbol from FRV code.

Signed-off-by: Jiri Olsa 
Acked-by: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds