linux.git/arch/powerpc/kernel/vdso64, branch v2.6.30

powerpc/mm: Introduce MMU features

2008-12-21T03:21:16+00:00

We're soon running out of CPU features and I need to add some new
ones for various MMU related bits, so this patch separates the MMU
features from the CPU features.  I moved over the 32-bit MMU related
ones, added base features for MMU type families, but didn't move
over any 64-bit only feature yet.

Signed-off-by: Benjamin Herrenschmidt 
Acked-by: Kumar Gala 
Signed-off-by: Paul Mackerras

powerpc: Improve resolution of VDSO clock_gettime

2008-11-05T22:49:22+00:00

Currently the clock_gettime implementation in the VDSO produces a
result with microsecond resolution for the cases that are handled
without a system call, i.e. CLOCK_REALTIME and CLOCK_MONOTONIC.  The
nanoseconds field of the result is obtained by computing a
microseconds value and multiplying by 1000.

This changes the code in the VDSO to do the computation for
clock_gettime with nanosecond resolution.  That means that the
resolution of the result will ultimately depend on the timebase
frequency.

Because the timestamp in the VDSO datapage (stamp_xsec, the real time
corresponding to the timebase count in tb_orig_stamp) is in units of
2^-20 seconds, it doesn't have sufficient resolution for computing a
result with nanosecond resolution.  Therefore this adds a copy of
xtime to the VDSO datapage and updates it in update_gtod() along with
the other time-related fields.

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

powerpc: Introduce infrastructure for feature sections with alternatives

2008-07-01T01:28:28+00:00

The current feature section logic only supports nop'ing out code, this means
if you want to choose at runtime between instruction sequences, one or both
cases will have to execute the nop'ed out contents of the other section, eg:

BEGIN_FTR_SECTION
	or	1,1,1
END_FTR_SECTION_IFSET(FOO)
BEGIN_FTR_SECTION
	or	2,2,2
END_FTR_SECTION_IFCLR(FOO)

and the resulting code will be either,

	or	1,1,1
	nop

or,
	nop
	or	2,2,2

For small code segments this is fine, but for larger code blocks and in
performance criticial code segments, it would be nice to avoid the nops.
This commit starts to implement logic to allow the following:

BEGIN_FTR_SECTION
	or	1,1,1
FTR_SECTION_ELSE
	or	2,2,2
ALT_FTR_SECTION_END_IFSET(FOO)

and the resulting code will be:

	or	1,1,1
or,
	or	2,2,2

We achieve this by extending the existing FTR macros. The current feature
section semantic just becomes a special case, ie. if the else case is empty
we nop out the default case.

The key limitation is that the size of the else case must be less than or
equal to the size of the default case. If the else case is smaller the
remainder of the section is nop'ed.

We let the linker put the else case code in with the rest of the text,
so that relative branches from the else case are more likley to link,
this has the disadvantage that we can't free the unused else cases.

This commit introduces the required macro and linker script changes, but
does not enable the patching of the alternative sections.

We also need to update two hand-made section entries in reg.h and timex.h

Signed-off-by: Michael Ellerman 
Signed-off-by: Paul Mackerras

[POWERPC] Tweak VDSO linker script to avoid upsetting old binutils

2008-05-23T05:27:23+00:00

This works around bugs in older binutils' objcopy.
The placement of these sections does not really matter,
but it confused the buggy old BFD libraries.

Signed-off-by: Roland McGrath 
Signed-off-by: Paul Mackerras

[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] Fix 64 bits vDSO DWARF info for CR register

2007-10-17T12:30:09+00:00

The current DWARF info for CR are incorrect, causing the gcc unwinder to
go to lunch if we take a segfault in the vdso.  This fixes it.

Problem identified by Andrew Haley, and fix provided by Jakub Jelinek
(thanks !).

Unfortunately, a bug in gcc cause it to not quite work either, but that
is being fixed separately with something around the lines of:

linux-unwind.h:

     fs->regs.reg[R_CR2].loc.offset = (long) ®s->ccr - new_cfa;
+    /* CR? regs are just 32-bit and PPC is big-endian.  */
+    fs->regs.reg[R_CR2].loc.offset += sizeof (long) - 4;

(According to Jakub)

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

powerpc64 vDSO: linker script indentation

2007-10-16T17:01:50+00:00

This cleans up the formatting in the vDSO linker script, mostly just the
use of whitespace.  It's intended to approximate the kernel standard
conventions for indenting C, treating elements of the linker script about
like initialized variable definitions.

Signed-off-by: Roland McGrath 
Acked-by: Benjamin Herrenschmidt 
Cc: Sam Ravnborg 
Signed-off-by: Linus Torvalds

[POWERPC] Update .gitignore for new vdso generated files

2007-10-08T13:38:12+00:00

We now generate vdso[32,64].so.dbg as part of the build so
add them to .gitignore

Signed-off-by: Kumar Gala

[POWERPC] powerpc vDSO: install unstripped copies on disk

2007-10-03T02:02:43+00:00

This keeps an unstripped copy of the vDSO images built before they are
stripped and embedded in the kernel.  The unstripped copies get installed in
$(MODLIB)/vdso/ by "make install".  These files can be useful when they
contain source-level debugging information.

Signed-off-by: Roland McGrath 
Cc: Sam Ravnborg 
Cc: Benjamin Herrenschmidt 
Signed-off-by: Andrew Morton 
Signed-off-by: Paul Mackerras