7 files changed, 49 insertions, 1 deletions

diff --git a/arch/powerpc/include/asm/opal-api.h b/arch/powerpc/include/asm/opal-api.h
index e1d118ac61dc..234fde15b37c 100644
--- a/arch/powerpc/include/asm/opal-api.h
+++ b/arch/powerpc/include/asm/opal-api.h
@@ -209,6 +209,7 @@
 #define OPAL_SENSOR_GROUP_ENABLE		163
 #define OPAL_PCI_GET_PBCQ_TUNNEL_BAR		164
 #define OPAL_PCI_SET_PBCQ_TUNNEL_BAR		165
+#define OPAL_HANDLE_HMI2			166
 #define	OPAL_NX_COPROC_INIT			167
 #define OPAL_XIVE_GET_VP_STATE			170
 #define OPAL_LAST				170
@@ -635,6 +636,15 @@ struct OpalHMIEvent {
 	} u;
 };
 
+/* OPAL_HANDLE_HMI2 out_flags */
+enum {
+	OPAL_HMI_FLAGS_TB_RESYNC	= (1ull << 0), /* Timebase has been resynced */
+	OPAL_HMI_FLAGS_DEC_LOST		= (1ull << 1), /* DEC lost, needs to be reprogrammed */
+	OPAL_HMI_FLAGS_HDEC_LOST	= (1ull << 2), /* HDEC lost, needs to be reprogrammed */
+	OPAL_HMI_FLAGS_TOD_TB_FAIL	= (1ull << 3), /* TOD/TB recovery failed. */
+	OPAL_HMI_FLAGS_NEW_EVENT	= (1ull << 63), /* An event has been created */
+};
+
 enum {
 	OPAL_P7IOC_DIAG_TYPE_NONE	= 0,
 	OPAL_P7IOC_DIAG_TYPE_RGC	= 1,
diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index 4e978d4dea5c..4cc37e708bc7 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -203,6 +203,7 @@ int64_t opal_set_param(uint64_t token, uint32_t param_id, uint64_t buffer,
 int64_t opal_sensor_read(uint32_t sensor_hndl, int token, __be32 *sensor_data);
 int64_t opal_sensor_read_u64(u32 sensor_hndl, int token, __be64 *sensor_data);
 int64_t opal_handle_hmi(void);
+int64_t opal_handle_hmi2(__be64 *out_flags);
 int64_t opal_register_dump_region(uint32_t id, uint64_t start, uint64_t end);
 int64_t opal_unregister_dump_region(uint32_t id);
 int64_t opal_slw_set_reg(uint64_t cpu_pir, uint64_t sprn, uint64_t val);
@@ -359,6 +360,7 @@ int opal_power_control_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_hmi_exception_early2(struct pt_regs *regs);
 extern int opal_handle_hmi_exception(struct pt_regs *regs);
 
 extern void opal_shutdown(void);
diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h
index 54bf7e68a7e1..57e968413d1e 100644
--- a/arch/powerpc/include/asm/time.h
+++ b/arch/powerpc/include/asm/time.h
@@ -36,6 +36,8 @@ extern unsigned long ppc_proc_freq;
 extern unsigned long ppc_tb_freq;
 #define DEFAULT_TB_FREQ		125000000UL
 
+extern bool tb_invalid;
+
 struct div_result {
 	u64 result_high;
 	u64 result_low;
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 6ef32472ee1d..325d60633dfa 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -150,6 +150,8 @@ EXPORT_SYMBOL_GPL(ppc_proc_freq);
 unsigned long ppc_tb_freq;
 EXPORT_SYMBOL_GPL(ppc_tb_freq);
 
+bool tb_invalid;
+
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 /*
  * Factor for converting from cputime_t (timebase ticks) to
@@ -459,6 +461,13 @@ void __delay(unsigned long loops)
 				diff += 1000000000;
 			spin_cpu_relax();
 		} while (diff < loops);
+	} else if (tb_invalid) {
+		/*
+		 * TB is in error state and isn't ticking anymore.
+		 * HMI handler was unable to recover from TB error.
+		 * Return immediately, so that kernel won't get stuck here.
+		 */
+		spin_cpu_relax();
 	} else {
 		start = get_tbl();
 		while (get_tbl() - start < loops)
diff --git a/arch/powerpc/platforms/powernv/opal-call.c b/arch/powerpc/platforms/powernv/opal-call.c
index 7cba0d5da3ff..36c8fa3647a2 100644
--- a/arch/powerpc/platforms/powernv/opal-call.c
+++ b/arch/powerpc/platforms/powernv/opal-call.c
@@ -220,6 +220,7 @@ OPAL_CALL(opal_sensor_read,			OPAL_SENSOR_READ);
 OPAL_CALL(opal_get_param,			OPAL_GET_PARAM);
 OPAL_CALL(opal_set_param,			OPAL_SET_PARAM);
 OPAL_CALL(opal_handle_hmi,			OPAL_HANDLE_HMI);
+OPAL_CALL(opal_handle_hmi2,			OPAL_HANDLE_HMI2);
 OPAL_CALL(opal_config_cpu_idle_state,		OPAL_CONFIG_CPU_IDLE_STATE);
 OPAL_CALL(opal_slw_set_reg,			OPAL_SLW_SET_REG);
 OPAL_CALL(opal_register_dump_region,		OPAL_REGISTER_DUMP_REGION);
diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index 737c51d63480..f2b063b027f0 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -614,6 +614,27 @@ int opal_hmi_exception_early(struct pt_regs *regs)
 	return 0;
 }
 
+int opal_hmi_exception_early2(struct pt_regs *regs)
+{
+	s64 rc;
+	__be64 out_flags;
+
+	/*
+	 * call opal hmi handler.
+	 * Check 64-bit flag mask to find out if an event was generated,
+	 * and whether TB is still valid or not etc.
+	 */
+	rc = opal_handle_hmi2(&out_flags);
+	if (rc != OPAL_SUCCESS)
+		return 0;
+
+	if (be64_to_cpu(out_flags) & OPAL_HMI_FLAGS_NEW_EVENT)
+		local_paca->hmi_event_available = 1;
+	if (be64_to_cpu(out_flags) & OPAL_HMI_FLAGS_TOD_TB_FAIL)
+		tb_invalid = true;
+	return 1;
+}
+
 /* HMI exception handler called in virtual mode during check_irq_replay. */
 int opal_handle_hmi_exception(struct pt_regs *regs)
 {
diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
index 14befee4b3f1..3cf40f689aac 100644
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c
@@ -401,7 +401,10 @@ static void __init pnv_setup_machdep_opal(void)
 	/* ppc_md.system_reset_exception gets filled in by pnv_smp_init() */
 	ppc_md.machine_check_exception = opal_machine_check;
 	ppc_md.mce_check_early_recovery = opal_mce_check_early_recovery;
-	ppc_md.hmi_exception_early = opal_hmi_exception_early;
+	if (opal_check_token(OPAL_HANDLE_HMI2))
+		ppc_md.hmi_exception_early = opal_hmi_exception_early2;
+	else
+		ppc_md.hmi_exception_early = opal_hmi_exception_early;
 	ppc_md.handle_hmi_exception = opal_handle_hmi_exception;
 }