linux-stable.git/include/asm-frv, branch linux-2.6.25.y

FRV: Don't make smp_{r, w, }mb() interpolate MEMBAR when CONFIG_SMP=n [try #2]

2008-04-10T20:41:29+00:00

Don't make smp_{r,w,}mb() interpolate a MEMBAR instruction when CONFIG_SMP=n as
SMP memory barries on UP systems should interpolate a compiler barrier only.

Signed-off-by: David Howells 
Signed-off-by: Linus Torvalds

FRV: Add support for emulation of userspace atomic ops [try #2]

2008-04-10T20:41:29+00:00

Use traps 120-126 to emulate atomic cmpxchg32, xchg32, and XOR-, OR-, AND-, SUB-
and ADD-to-memory operations for userspace.

Signed-off-by: David Howells 
Signed-off-by: Linus Torvalds

FRV: Move STACK_TOP_MAX up [try #2]

2008-04-10T20:41:28+00:00

Move STACK_TOP_MAX up so that we don't try moving the stack above it as that
causes setup_arg_pages() to malfunction.

Signed-off-by: David Howells 
Signed-off-by: Linus Torvalds

FRV: Handle update_mmu_cache() being called when current->mm is NULL [try #2]

2008-04-10T20:41:28+00:00

Handle update_mmu_cache() being called when current->mm is NULL.

We cache static TLB mappings for the current page table in DAMPR4 and DAMPR5
on the theory that the next data lookup is likely to be in the same general
region, and thus is likely to be mapped by the same page table.  However, we
can't get this information if we can't access the appropriate mm_struct.

If current->mm is NULL, we just clear the cache in the knowledge that the TLB
miss handlers will load it.

Signed-off-by: David Howells 
Signed-off-by: Linus Torvalds

kvm: provide kvm.h for all architecture: fixes headers_install

2008-04-02T22:28:18+00:00

Currently include/linux/kvm.h is not considered by make headers_install,
because Kbuild cannot handle " unifdef-$(CONFIG_FOO) += foo.h.  This problem
was introduced by

commit fb56dbb31c4738a3918db81fd24da732ce3b4ae6
Author: Avi Kivity 
Date:   Sun Dec 2 10:50:06 2007 +0200

    KVM: Export include/linux/kvm.h only if $ARCH actually supports KVM

    Currently, make headers_check barfs due to , which 
    includes, not existing.  Rather than add a zillion s, export kvm.
    only if the arch actually supports it.

    Signed-off-by: Avi Kivity 

which makes this an 2.6.25 regression.

One way of solving the issue is to enhance Kbuild, but Avi and David conviced
me, that changing headers_install is not the way to go.  This patch changes
the definition for linux/kvm.h to unifdef-y.

If  unifdef-y is used for linux/kvm.h "make headers_check" will fail on all
architectures without asm/kvm.h.  Therefore, this patch also provides
asm/kvm.h on all architectures.

Signed-off-by: Christian Borntraeger 
Acked-by: Avi Kivity 
Cc: Sam Ravnborg 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

NULL noise: frv cmpxchg()

2008-03-30T21:20:23+00:00

Signed-off-by: Al Viro 
Acked-by: Harvey Harrison 
Signed-off-by: Linus Torvalds

FRV: Change the timerfd syscalls to be the same as i386

2008-02-21T03:58:16+00:00

Change the FRV timerfd syscalls to be the same as i386 timerfd syscalls.

Signed-off-by: David Howells 
Signed-off-by: Linus Torvalds

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