History log of /arch/powerpc/lib/feature-fixups.c
Revision Date Author Comments
d715e433b7ad19c02fc4becf0d5e9a59f97925de 14-Nov-2011 Anton Blanchard <anton@samba.org> powerpc: Copy down exception vectors after feature fixups

kdump fails because we try to execute an HV only instruction. Feature
fixups are being applied after we copy the exception vectors down to 0
so they miss out on any updates.

We have always had this issue but it only became critical in v3.0
when we added CFAR support (breaks POWER5) and v3.1 when we added
POWERNV (breaks everyone).

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: <stable@kernel.org> [v3.0+]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
3880ecb05bc5ece4c6e392a21ea77518e55b4935 28-Jun-2010 Stephen Rothwell <sfr@canb.auug.org.au> powerpc: Fix feature-fixup tests for gcc 4.5

The feature-fixup test declare some extern void variables and then take
their addresses. Fix this by declaring them as extern u8 instead.

Fixes these warnings (treated as errors):

CC arch/powerpc/lib/feature-fixups.o
cc1: warnings being treated as errors
arch/powerpc/lib/feature-fixups.c: In function 'test_cpu_macros':
arch/powerpc/lib/feature-fixups.c:293:23: error: taking address of expression of type 'void'
arch/powerpc/lib/feature-fixups.c:294:9: error: taking address of expression of type 'void'
arch/powerpc/lib/feature-fixups.c:297:2: error: taking address of expression of type 'void'
arch/powerpc/lib/feature-fixups.c:297:2: error: taking address of expression of type 'void'
arch/powerpc/lib/feature-fixups.c: In function 'test_fw_macros':
arch/powerpc/lib/feature-fixups.c:306:23: error: taking address of expression of type 'void'
arch/powerpc/lib/feature-fixups.c:307:9: error: taking address of expression of type 'void'
arch/powerpc/lib/feature-fixups.c:310:2: error: taking address of expression of type 'void'
arch/powerpc/lib/feature-fixups.c:310:2: error: taking address of expression of type 'void'
arch/powerpc/lib/feature-fixups.c: In function 'test_lwsync_macros':
arch/powerpc/lib/feature-fixups.c:321:23: error: taking address of expression of type 'void'
arch/powerpc/lib/feature-fixups.c:322:9: error: taking address of expression of type 'void'
arch/powerpc/lib/feature-fixups.c:326:3: error: taking address of expression of type 'void'
arch/powerpc/lib/feature-fixups.c:326:3: error: taking address of expression of type 'void'
arch/powerpc/lib/feature-fixups.c:329:3: error: taking address of expression of type 'void'
arch/powerpc/lib/feature-fixups.c:329:3: error: taking address of expression of type 'void'

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
3d98ffbffb16f2a1569b83cb78db0b5100e6c937 26-Feb-2010 Benjamin Herrenschmidt <benh@kernel.crashing.org> powerpc: Fix lwsync feature fixup vs. modules on 64-bit

Anton's commit enabling the use of the lwsync fixup mechanism on 64-bit
breaks modules. The lwsync fixup section uses .long instead of the
FTR_ENTRY_OFFSET macro used by other fixups sections, and thus will
generate 32-bit relocations that our module loader cannot resolve.

This changes it to use the same type as other feature sections.

Note however that we might want to consider using 32-bit for all the
feature fixup offsets and add support for R_PPC_REL32 to module_64.c
instead as that would reduce the size of the kernel image. I'll leave
that as an exercise for the reader for now...

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
53eae2281ad2607fa66a8ad1cb06186c8900da56 10-Feb-2010 Anton Blanchard <anton@samba.org> powerpc: Fix lwsync patching code on 64bit

do_lwsync_fixups doesn't work on 64bit, we end up writing lwsyncs to the
wrong addresses:

0:mon> di c0000001000bfacc
c0000001000bfacc 7c2004ac lwsync

Since the lwsync section has negative offsets we need to use a signed int
pointer so we sign extend the value.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
16c57b3620d77e0bc981da5ef32beae730512684 10-Feb-2009 Kumar Gala <galak@kernel.crashing.org> powerpc: Unify opcode definitions and support

Create a new header that becomes a single location for defining PowerPC
opcodes used by code that is either generationg instructions
at runtime (fixups, debug, etc.), emulating instructions, or just
compiling instructions old assemblers don't know about.

We currently don't handle the floating point emulation or alignment decode
as both are better handled by the specific decode support they already
have.

Added support for the new dcbzl, dcbal, msgsnd, tlbilx, & wait instructions
since older assemblers don't know about them.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
1856c020402f602b2bd26bcc9b77250304565b7e 17-Jul-2008 Michael Ellerman <michael@ellerman.id.au> powerpc: Use WARN_ON(1) instead of __WARN()

__WARN() is not defined for all configs, use WARN_ON(1) instead.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2d1b2027626d5151fff8ef7c06ca8e7876a1a510 01-Jul-2008 Kumar Gala <galak@kernel.crashing.org> powerpc: Fixup lwsync at runtime

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 <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
362e7701fd183d990e0863883461edef61392710 24-Jun-2008 Michael Ellerman <michael@ellerman.id.au> powerpc: Add self-tests of the feature fixup code

This commit adds tests of the feature fixup code, they are run during
boot if CONFIG_FTR_FIXUP_SELFTEST=y. Some of the tests manually invoke
the patching routines to check their behaviour, and others use the
macros and so are patched during the normal patching done during boot.

Because we have two sets of macros with different names, we use a macro
to generate the test of the macros, very niiiice.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
9b1a735de64cc975c31a1642ec55e082ddbdfeaf 24-Jun-2008 Michael Ellerman <michael@ellerman.id.au> powerpc: Add logic to patch alternative feature sections

This commit adds the logic to patch alternative sections. This is fairly
straightforward, except for branches. Relative branches that jump from
inside the else section to outside of it need to be translated as they're
moved, otherwise they will jump to the wrong location.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
fac23fe4be23259a8eaa9bad822f5b14dd07d15c 24-Jun-2008 Michael Ellerman <michael@ellerman.id.au> powerpc: Introduce infrastructure for feature sections with alternatives

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 <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
51c52e86694f19e84600a40f6156889feafd8ae9 24-Jun-2008 Michael Ellerman <michael@ellerman.id.au> powerpc: Split out do_feature_fixups() from cputable.c

The logic to patch CPU feature sections lives in cputable.c, but these days
it's used for CPU features as well as firmware features. Move it into
it's own file for neatness and as preparation for some additions.

While we're moving the code, we pull the loop body logic into a separate
routine, and remove a comment which doesn't apply anymore.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>