powerpc/book3s: Add basic infrastructure to handle HMI in Linux.

Handle Hypervisor Maintenance Interrupt (HMI) in Linux. This patch implements
basic infrastructure to handle HMI in Linux host. The design is to invoke
opal handle hmi in real mode for recovery and set irq_pending when we hit HMI.
During check_irq_replay pull opal hmi event and print hmi info on console.

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

6 files changed, 11 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index 13a63379e496..77f52b26dad6 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -425,6 +425,8 @@ label##_relon_hv:						\
 #define SOFTEN_VALUE_0xa00	PACA_IRQ_DBELL
 #define SOFTEN_VALUE_0xe80	PACA_IRQ_DBELL
 #define SOFTEN_VALUE_0xe82	PACA_IRQ_DBELL
+#define SOFTEN_VALUE_0xe60	PACA_IRQ_HMI
+#define SOFTEN_VALUE_0xe62	PACA_IRQ_HMI
 
 #define __SOFTEN_TEST(h, vec)						\
 	lbz	r10,PACASOFTIRQEN(r13);					\
diff --git a/arch/powerpc/include/asm/hardirq.h b/arch/powerpc/include/asm/hardirq.h
index 418fb654370d..1bbb3013d6aa 100644
--- a/arch/powerpc/include/asm/hardirq.h
+++ b/arch/powerpc/include/asm/hardirq.h
@@ -11,6 +11,7 @@ typedef struct {
 	unsigned int pmu_irqs;
 	unsigned int mce_exceptions;
 	unsigned int spurious_irqs;
+	unsigned int hmi_exceptions;
 #ifdef CONFIG_PPC_DOORBELL
 	unsigned int doorbell_irqs;
 #endif
diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
index 10be1dd01c6b..b59ac27a6b7d 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h
@@ -25,6 +25,7 @@
 #define PACA_IRQ_EE		0x04
 #define PACA_IRQ_DEC		0x08 /* Or FIT */
 #define PACA_IRQ_EE_EDGE	0x10 /* BookE only */
+#define PACA_IRQ_HMI		0x20
 
 #endif /* CONFIG_PPC64 */
 
diff --git a/arch/powerpc/include/asm/kvm_asm.h b/arch/powerpc/include/asm/kvm_asm.h
index 9601741080e5..ecf7e133a4f2 100644
--- a/arch/powerpc/include/asm/kvm_asm.h
+++ b/arch/powerpc/include/asm/kvm_asm.h
@@ -98,6 +98,7 @@
 #define BOOK3S_INTERRUPT_H_DATA_STORAGE	0xe00
 #define BOOK3S_INTERRUPT_H_INST_STORAGE	0xe20
 #define BOOK3S_INTERRUPT_H_EMUL_ASSIST	0xe40
+#define BOOK3S_INTERRUPT_HMI		0xe60
 #define BOOK3S_INTERRUPT_H_DOORBELL	0xe80
 #define BOOK3S_INTERRUPT_PERFMON	0xf00
 #define BOOK3S_INTERRUPT_ALTIVEC	0xf20
diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h
index 5c7e74ddee4c..44e90516519b 100644
--- a/arch/powerpc/include/asm/machdep.h
+++ b/arch/powerpc/include/asm/machdep.h
@@ -174,6 +174,10 @@ struct machdep_calls {
 	/* Exception handlers */
 	int		(*system_reset_exception)(struct pt_regs *regs);
 	int 		(*machine_check_exception)(struct pt_regs *regs);
+	int		(*handle_hmi_exception)(struct pt_regs *regs);
+
+	/* Early exception handlers called in realmode */
+	int		(*hmi_exception_early)(struct pt_regs *regs);
 
 	/* Called during machine check exception to retrive fixup address. */
 	bool		(*mce_check_early_recovery)(struct pt_regs *regs);
diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index 7f5fd5396261..efc16c37b959 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -915,6 +915,8 @@ extern void opal_msglog_init(void);
 
 extern int opal_machine_check(struct pt_regs *regs);
 extern bool opal_mce_check_early_recovery(struct pt_regs *regs);
+extern int opal_hmi_exception_early(struct pt_regs *regs);
+extern int opal_handle_hmi_exception(struct pt_regs *regs);
 
 extern void opal_shutdown(void);
 extern int opal_resync_timebase(void);