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authorMark Nelson <markn@au1.ibm.com>2010-02-07 16:45:12 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2010-02-08 15:29:19 +1100
commit36350e00696df148507246c817cf6f86329479fd (patch)
tree2a57c7ae1583006658eea1c35232caf5b7cef7ee /arch
parent1a45dcfe2525e9432cb4aba461d4994fc2befe42 (diff)
downloadlinux-linaro-stable-36350e00696df148507246c817cf6f86329479fd.tar.gz
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>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/platforms/pseries/xics.c14
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 */