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| author | Mark Nelson <markn@au1.ibm.com> | 2010-02-07 16:45:12 +0000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2010-02-08 15:29:19 +1100 |
| commit | 36350e00696df148507246c817cf6f86329479fd (patch) | |
| tree | 2a57c7ae1583006658eea1c35232caf5b7cef7ee | |
| parent | 1a45dcfe2525e9432cb4aba461d4994fc2befe42 (diff) | |
| download | linux-36350e00696df148507246c817cf6f86329479fd.tar.gz linux-36350e00696df148507246c817cf6f86329479fd.tar.bz2 linux-36350e00696df148507246c817cf6f86329479fd.zip | |
powerpc/pseries: Fix kexec regression caused by CPPR tracking
The code to track the CPPR values added by commit
49bd3647134ea47420067aea8d1401e722bf2aac ("powerpc/pseries: Track previous
CPPR values to correctly EOI interrupts") broke kexec on pseries because
the kexec code in xics.c calls xics_set_cpu_priority() before the IPI has
been EOI'ed. This wasn't a problem previously but it now triggers a BUG_ON
in xics_set_cpu_priority() because os_cppr->index isn't 0.
Fix this problem by setting the index on the CPPR stack to 0 before calling
xics_set_cpu_priority() in xics_teardown_cpu().
Also make it clear that we only want to set the priority when there's just
one CPPR value in the stack, and enforce it by updating the value of
os_cppr->stack[0] rather than os_cppr->stack[os_cppr->index].
While we're at it change the BUG_ON to a WARN_ON.
Reported-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Mark Nelson <markn@au1.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| -rw-r--r-- | arch/powerpc/platforms/pseries/xics.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/arch/powerpc/platforms/pseries/xics.c b/arch/powerpc/platforms/pseries/xics.c index 1ee66db003be..f5f79196721c 100644 --- a/arch/powerpc/platforms/pseries/xics.c +++ b/arch/powerpc/platforms/pseries/xics.c @@ -784,9 +784,13 @@ static void xics_set_cpu_priority(unsigned char cppr) { struct xics_cppr *os_cppr = &__get_cpu_var(xics_cppr); - BUG_ON(os_cppr->index != 0); + /* + * we only really want to set the priority when there's + * just one cppr value on the stack + */ + WARN_ON(os_cppr->index != 0); - os_cppr->stack[os_cppr->index] = cppr; + os_cppr->stack[0] = cppr; if (firmware_has_feature(FW_FEATURE_LPAR)) lpar_cppr_info(cppr); @@ -821,8 +825,14 @@ void xics_setup_cpu(void) void xics_teardown_cpu(void) { + struct xics_cppr *os_cppr = &__get_cpu_var(xics_cppr); int cpu = smp_processor_id(); + /* + * we have to reset the cppr index to 0 because we're + * not going to return from the IPI + */ + os_cppr->index = 0; xics_set_cpu_priority(0); /* Clear any pending IPI request */ |