Add a test of the relative branch patching logic in the alternate
section feature fixup code. This tests that if we branch past the last
instruction of the alternate section, the branch is not patched.
That's because the assembler will have created a branch that already
points to the first instruction after the patched section, which is
correct and needs no further patching.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We want this to remain the last test (because it's disabled by
default), so give it a non-numbered name so we don't have to renumber
it when adding new tests before it.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The expected case for this test was wrong, the source of the alternate
code sequence is:
FTR_SECTION_ELSE
2: or 2,2,2
PPC_LCMPI r3,1
beq 3f
blt 2b
b 3f
b 1b
ALT_FTR_SECTION_END(0, 1)
3: or 1,1,1
or 2,2,2
4: or 3,3,3
So when it's patched the '3' label should still be on the 'or 1,1,1',
and the 4 label is irrelevant and can be removed.
Fixes: 362e7701fd ("powerpc: Add self-tests of the feature fixup code")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When we create an alternative feature section, the else case must be the
same size or smaller than the body. This is because when we patch the
else case in we just overwrite the body, so there must be room.
Up to now we just did this by inspection, but it's quite easy to enforce
it in the assembler, so we should.
The only change is to add the ifgt block, but that effects the alignment
of the tabs and so the whole macro is modified.
Also add a test, but #if 0 it because we don't want to break the build.
Anyone who's modifying the feature macros should enable the test.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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>
We need to use PPC_LCMPI otherwise we get compile errors like:
arch/powerpc/lib/feature-fixups-test.S: Assembler messages:
arch/powerpc/lib/feature-fixups-test.S:142: Error: Unrecognized opcode: `cmpdi'
arch/powerpc/lib/feature-fixups-test.S:149: Error: Unrecognized opcode: `cmpdi'
arch/powerpc/lib/feature-fixups-test.S:164: Error: Unrecognized opcode: `cmpdi'
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
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>
Michael Ellerman