1 files changed, 67 insertions, 9 deletions

diff --git a/arch/powerpc/sysdev/xics/icp-opal.c b/arch/powerpc/sysdev/xics/icp-opal.c
index d38e86fd5720..b53f80f0b4d8 100644
--- a/arch/powerpc/sysdev/xics/icp-opal.c
+++ b/arch/powerpc/sysdev/xics/icp-opal.c
@@ -20,6 +20,7 @@
 #include <asm/xics.h>
 #include <asm/io.h>
 #include <asm/opal.h>
+#include <asm/kvm_ppc.h>
 
 static void icp_opal_teardown_cpu(void)
 {
@@ -39,7 +40,26 @@ static void icp_opal_flush_ipi(void)
 	 * Should we be flagging idle loop instead?
 	 * Or creating some task to be scheduled?
 	 */
-	opal_int_eoi((0x00 << 24) | XICS_IPI);
+	if (opal_int_eoi((0x00 << 24) | XICS_IPI) > 0)
+		force_external_irq_replay();
+}
+
+static unsigned int icp_opal_get_xirr(void)
+{
+	unsigned int kvm_xirr;
+	__be32 hw_xirr;
+	int64_t rc;
+
+	/* Handle an interrupt latched by KVM first */
+	kvm_xirr = kvmppc_get_xics_latch();
+	if (kvm_xirr)
+		return kvm_xirr;
+
+	/* Then ask OPAL */
+	rc = opal_int_get_xirr(&hw_xirr, false);
+	if (rc < 0)
+		return 0;
+	return be32_to_cpu(hw_xirr);
 }
 
 static unsigned int icp_opal_get_irq(void)
@@ -47,12 +67,8 @@ static unsigned int icp_opal_get_irq(void)
 	unsigned int xirr;
 	unsigned int vec;
 	unsigned int irq;
-	int64_t rc;
 
-	rc = opal_int_get_xirr(&xirr, false);
-	if (rc < 0)
-		return 0;
-	xirr = be32_to_cpu(xirr);
+	xirr = icp_opal_get_xirr();
 	vec = xirr & 0x00ffffff;
 	if (vec == XICS_IRQ_SPURIOUS)
 		return 0;
@@ -67,13 +83,24 @@ static unsigned int icp_opal_get_irq(void)
 	xics_mask_unknown_vec(vec);
 
 	/* We might learn about it later, so EOI it */
-	opal_int_eoi(xirr);
+	if (opal_int_eoi(xirr) > 0)
+		force_external_irq_replay();
 
 	return 0;
 }
 
 static void icp_opal_set_cpu_priority(unsigned char cppr)
 {
+	/*
+	 * Here be dragons. The caller has asked to allow only IPI's and not
+	 * external interrupts. But OPAL XIVE doesn't support that. So instead
+	 * of allowing no interrupts allow all. That's still not right, but
+	 * currently the only caller who does this is xics_migrate_irqs_away()
+	 * and it works in that case.
+	 */
+	if (cppr >= DEFAULT_PRIORITY)
+		cppr = LOWEST_PRIORITY;
+
 	xics_set_base_cppr(cppr);
 	opal_int_set_cppr(cppr);
 	iosync();
@@ -103,18 +130,49 @@ static void icp_opal_cause_ipi(int cpu, unsigned long data)
 {
 	int hw_cpu = get_hard_smp_processor_id(cpu);
 
+	kvmppc_set_host_ipi(cpu, 1);
 	opal_int_set_mfrr(hw_cpu, IPI_PRIORITY);
 }
 
 static irqreturn_t icp_opal_ipi_action(int irq, void *dev_id)
 {
-	int hw_cpu = hard_smp_processor_id();
+	int cpu = smp_processor_id();
 
-	opal_int_set_mfrr(hw_cpu, 0xff);
+	kvmppc_set_host_ipi(cpu, 0);
+	opal_int_set_mfrr(get_hard_smp_processor_id(cpu), 0xff);
 
 	return smp_ipi_demux();
 }
 
+/*
+ * Called when an interrupt is received on an off-line CPU to
+ * clear the interrupt, so that the CPU can go back to nap mode.
+ */
+void icp_opal_flush_interrupt(void)
+{
+	unsigned int xirr;
+	unsigned int vec;
+
+	do {
+		xirr = icp_opal_get_xirr();
+		vec = xirr & 0x00ffffff;
+		if (vec == XICS_IRQ_SPURIOUS)
+			break;
+		if (vec == XICS_IPI) {
+			/* Clear pending IPI */
+			int cpu = smp_processor_id();
+			kvmppc_set_host_ipi(cpu, 0);
+			opal_int_set_mfrr(get_hard_smp_processor_id(cpu), 0xff);
+		} else {
+			pr_err("XICS: hw interrupt 0x%x to offline cpu, "
+			       "disabling\n", vec);
+			xics_mask_unknown_vec(vec);
+		}
+
+		/* EOI the interrupt */
+	} while (opal_int_eoi(xirr) > 0);
+}
+
 #endif /* CONFIG_SMP */
 
 static const struct icp_ops icp_opal_ops = {