aboutsummaryrefslogtreecommitdiff
path: root/arch
diff options
context:
space:
mode:
authorPaul Mackerras <paulus@samba.org>2012-07-26 13:56:11 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2012-09-05 16:05:19 +1000
commitdabe859ec6360a12e71f39bf695d174e19ff2688 (patch)
treeea6312a3280966141e3bdf4c643f4ffad4506606 /arch
parent79c5fcebfe4021f326a6715009f0b6b622d5df92 (diff)
downloadlinux-linaro-stable-dabe859ec6360a12e71f39bf695d174e19ff2688.tar.gz
powerpc: Give hypervisor decrementer interrupts their own handler
At the moment the handler for hypervisor decrementer interrupts is the same as for decrementer interrupts, i.e. timer_interrupt(). This is bogus; if we ever do get a hypervisor decrementer interrupt it won't have anything to do with the next timer event. In fact the only time we get hypervisor decrementer interrupts is when one is left pending on exit from a KVM guest. When we get a hypervisor decrementer interrupt we don't need to do anything special to clear it, since they are edge-triggered on the transition of HDEC from 0 to -1. Thus this adds an empty handler function for them. We don't need to have them masked when interrupts are soft-disabled, so we use STD_EXCEPTION_HV instead of MASKABLE_EXCEPTION_HV. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/kernel/exceptions-64s.S3
-rw-r--r--arch/powerpc/kernel/time.c9
2 files changed, 11 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index e894515e77bb..39aa97d3ff88 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -186,7 +186,7 @@ hardware_interrupt_hv:
KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0x800)
MASKABLE_EXCEPTION_PSERIES(0x900, 0x900, decrementer)
- MASKABLE_EXCEPTION_HV(0x980, 0x982, decrementer)
+ STD_EXCEPTION_HV(0x980, 0x982, hdecrementer)
STD_EXCEPTION_PSERIES(0xa00, 0xa00, trap_0a)
KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0xa00)
@@ -486,6 +486,7 @@ machine_check_common:
STD_EXCEPTION_COMMON_ASYNC(0x500, hardware_interrupt, do_IRQ)
STD_EXCEPTION_COMMON_ASYNC(0x900, decrementer, .timer_interrupt)
+ STD_EXCEPTION_COMMON(0x980, hdecrementer, .hdec_interrupt)
STD_EXCEPTION_COMMON(0xa00, trap_0a, .unknown_exception)
STD_EXCEPTION_COMMON(0xb00, trap_0b, .unknown_exception)
STD_EXCEPTION_COMMON(0xd00, single_step, .single_step_exception)
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index be171ee73bf8..e49e93191b69 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -535,6 +535,15 @@ void timer_interrupt(struct pt_regs * regs)
trace_timer_interrupt_exit(regs);
}
+/*
+ * Hypervisor decrementer interrupts shouldn't occur but are sometimes
+ * left pending on exit from a KVM guest. We don't need to do anything
+ * to clear them, as they are edge-triggered.
+ */
+void hdec_interrupt(struct pt_regs *regs)
+{
+}
+
#ifdef CONFIG_SUSPEND
static void generic_suspend_disable_irqs(void)
{