linux-stable.git/arch/powerpc/kernel/vdso.c, branch linux-2.6.28.y

powerpc: Remove use of CONFIG_PPC_MERGE

2008-08-04T03:18:17+00:00

Now that arch/ppc is gone and CONFIG_PPC_MERGE is always set, remove
the dead code associated with !CONFIG_PPC_MERGE from arch/powerpc
and include/asm-powerpc.

Signed-off-by: Kumar Gala 
Signed-off-by: Paul Mackerras

powerpc: Fixup lwsync at runtime

2008-07-03T06:58:10+00:00

To allow for a single kernel image on e500 v1/v2/mc we need to fixup lwsync
at runtime.  On e500v1/v2 lwsync causes an illop so we need to patch up
the code.  We default to 'sync' since that is always safe and if the cpu
is capable we will replace 'sync' with 'lwsync'.

We introduce CPU_FTR_LWSYNC as a way to determine at runtime if this is
needed.  This flag could be moved elsewhere since we dont really use it
for the normal CPU_FTR purpose.

Finally we only store the relative offset in the fixup section to keep it
as small as possible rather than using a full fixup_entry.

Signed-off-by: Kumar Gala 
Signed-off-by: Paul Mackerras

Reinstate ZERO_PAGE optimization in 'get_user_pages()' and fix XIP

2008-06-20T18:18:25+00:00

KAMEZAWA Hiroyuki and Oleg Nesterov point out that since the commit
557ed1fa2620dc119adb86b34c614e152a629a80 ("remove ZERO_PAGE") removed
the ZERO_PAGE from the VM mappings, any users of get_user_pages() will
generally now populate the VM with real empty pages needlessly.

We used to get the ZERO_PAGE when we did the "handle_mm_fault()", but
since fault handling no longer uses ZERO_PAGE for new anonymous pages,
we now need to handle that special case in follow_page() instead.

In particular, the removal of ZERO_PAGE effectively removed the core
file writing optimization where we would skip writing pages that had not
been populated at all, and increased memory pressure a lot by allocating
all those useless newly zeroed pages.

This reinstates the optimization by making the unmapped PTE case the
same as for a non-existent page table, which already did this correctly.

While at it, this also fixes the XIP case for follow_page(), where the
caller could not differentiate between the case of a page that simply
could not be used (because it had no "struct page" associated with it)
and a page that just wasn't mapped.

We do that by simply returning an error pointer for pages that could not
be turned into a "struct page *".  The error is arbitrarily picked to be
EFAULT, since that was what get_user_pages() already used for the
equivalent IO-mapped page case.

[ Also removed an impossible test for pte_offset_map_lock() failing:
  that's not how that function works ]

Acked-by: Oleg Nesterov 
Acked-by: Nick Piggin 
Cc: KAMEZAWA Hiroyuki 
Cc: Hugh Dickins 
Cc: Andrew Morton 
Cc: Ingo Molnar 
Cc: Roland McGrath 
Signed-off-by: Linus Torvalds

Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/lmb-2.6

2008-02-26T10:08:45+00:00

[POWERPC] vdso_do_func_patch{32,64}() must be __init

2008-02-14T11:11:02+00:00

This fixes the following section mismatches:

<--  snip  -->

...
WARNING: vmlinux.o(.text+0xe49c): Section mismatch in reference from the function .vdso_do_func_patch64() to the function .init.text:.find_symbol64()
WARNING: vmlinux.o(.text+0xe4d0): Section mismatch in reference from the function .vdso_do_func_patch64() to the function .init.text:.find_symbol64()
WARNING: vmlinux.o(.text+0xe56c): Section mismatch in reference from the function .vdso_do_func_patch32() to the function .init.text:.find_symbol32()
WARNING: vmlinux.o(.text+0xe5a0): Section mismatch in reference from the function .vdso_do_func_patch32() to the function .init.text:.find_symbol32()
...

<--  snip  -->

Signed-off-by: Adrian Bunk 
Signed-off-by: Paul Mackerras

[LIB]: Make PowerPC LMB code generic so sparc64 can use it too.

2008-02-14T00:56:49+00:00

Signed-off-by: David S. Miller

[POWERPC] vdso: Fixes for cache block sizes

2007-11-20T02:56:31+00:00

The current VDSO implementation is hardcoded to 128 byte cache blocks,
which are only used on IBM's 64-bit processors.

Convert it to get the cache block sizes out of vdso_data instead,
similar to how the ppc64 in-kernel cache flush does it.

Signed-off-by: Olof Johansson 
Signed-off-by: Paul Mackerras

[POWERPC] Disable vDSO support for ARCH=ppc where it's not implemented

2007-10-11T10:25:25+00:00

Signed-off-by: Wolfgang Denk 
Signed-off-by: Paul Mackerras

[POWERPC] Don't expose clock vDSO functions when CPU has no timebase

2007-09-19T05:26:34+00:00

We forgot to remove the clock_gettime, clock_getres and get_tbfreq vDSO
calls on CPUs that have no timebase such as 601 or 403 (old CPUs that have
different mechanisms and for which the vDSO code will not work properly).
This fixes it.

Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Paul Mackerras

[POWERPC] Fix VDSO compile warning

2007-06-14T12:29:55+00:00

Maybe the type should have been char[] instead of __u8[]
in the first place, but this will do.

Signed-off-by: Segher Boessenkool 
Signed-off-by: Paul Mackerras