powerpc: NMI IPIs

index 0d02c11..055918d 100644
@@ -115,7 +115,7 @@ extern int cpu_to_core_id(int cpu);
 #define PPC_MSG_CALL_FUNCTION   0
 #define PPC_MSG_RESCHEDULE      1
 #define PPC_MSG_TICK_BROADCAST	2
-#define PPC_MSG_DEBUGGER_BREAK  3
+#define PPC_MSG_NMI_IPI_SAFE	3
 
 /* This is only used by the powernv kernel */
 #define PPC_MSG_RM_HOST_ACTION	4

335 lines not on this page · raw message

index a6bbbab..fcc94c8 100644
@@ -211,7 +211,7 @@ void iic_request_IPIs(void)
 	iic_request_ipi(PPC_MSG_CALL_FUNCTION);
 	iic_request_ipi(PPC_MSG_RESCHEDULE);
 	iic_request_ipi(PPC_MSG_TICK_BROADCAST);
-	iic_request_ipi(PPC_MSG_DEBUGGER_BREAK);
+	iic_request_ipi(PPC_MSG_NMI_IPI_SAFE);
 }
 
 #endif /* CONFIG_SMP */

index 60154d0..5b1fb70 100644
@@ -77,7 +77,7 @@ static void __init ps3_smp_probe(void)
 		BUILD_BUG_ON(PPC_MSG_CALL_FUNCTION    != 0);
 		BUILD_BUG_ON(PPC_MSG_RESCHEDULE       != 1);
 		BUILD_BUG_ON(PPC_MSG_TICK_BROADCAST   != 2);
-		BUILD_BUG_ON(PPC_MSG_DEBUGGER_BREAK   != 3);
+		BUILD_BUG_ON(PPC_MSG_NMI_IPI_SAFE   != 3);
 
 		for (i = 0; i < MSG_COUNT; i++) {
 			result = ps3_event_receive_port_setup(cpu, &virqs[i]);

@@ -96,7 +96,7 @@ static void __init ps3_smp_probe(void)
 				ps3_register_ipi_irq(cpu, virqs[i]);
 		}
 
-		ps3_register_ipi_debug_brk(cpu, virqs[PPC_MSG_DEBUGGER_BREAK]);
+		ps3_register_ipi_debug_brk(cpu, virqs[PPC_MSG_NMI_IPI_SAFE]);
 
 		DBG(" <- %s:%d: (%d)\n", __func__, __LINE__, cpu);
 	}

index 055918d..15521c1 100644
@@ -37,11 +37,15 @@ extern int cpu_to_chip_id(int cpu);
 
 #ifdef CONFIG_SMP
 
+#define SMP_OP_NMI_TYPE_SAFE	1
+#define SMP_OP_NMI_TYPE_HARD	2
+
 struct smp_ops_t {
 	void  (*message_pass)(int cpu, int msg);
 #ifdef CONFIG_PPC_SMP_MUXED_IPI
 	void  (*cause_ipi)(int cpu, unsigned long data);
 #endif
+	int   (*cause_nmi_ipi)(int cpu, int type);
 	void  (*probe)(void);
 	int   (*kick_cpu)(int nr);
 	void  (*setup_cpu)(int nr);

@@ -53,6 +57,7 @@ struct smp_ops_t {
 	int   (*cpu_bootable)(unsigned int nr);
 };
 
+extern int smp_handle_nmi_ipi(struct pt_regs *regs);
 extern void smp_send_debugger_break(void);
 extern void start_secondary_resume(void);
 extern void smp_generic_give_timebase(void);

index 959d9dc..b3133e9 100644
@@ -425,8 +425,10 @@ int smp_handle_nmi_ipi(struct pt_regs *regs)
 	return ret;
 }
 
-static void do_smp_send_nmi_ipi(int cpu)
+static void do_smp_send_nmi_ipi(int cpu, int type)
 {
+	if (smp_ops->cause_nmi_ipi && smp_ops->cause_nmi_ipi(cpu, type))
+		return;
 	do_message_pass(cpu, PPC_MSG_NMI_IPI_SAFE);
 }
 

@@ -453,9 +455,6 @@ int smp_send_nmi_ipi(int cpu, int function, void *data,
 	if (unlikely(!smp_ops))
 		return 0;
 
-	/* Have no real NMI capability yet */
-	safe_udelay += hard_udelay;
-
 	get_online_cpus();
 
 	/* Take the nmi_ipi_busy count/lock with interrupts hard disabled */

@@ -482,7 +481,7 @@ int smp_send_nmi_ipi(int cpu, int function, void *data,
 
 	if (safe_udelay) {
 		for_each_cpu(c, &nmi_ipi_pending_mask)
-			do_smp_send_nmi_ipi(c);
+			do_smp_send_nmi_ipi(c, SMP_OP_NMI_TYPE_SAFE);
 
 		do {
 			safe_udelay--;

@@ -492,6 +491,18 @@ int smp_send_nmi_ipi(int cpu, int function, void *data,
 		} while (safe_udelay);
 	}
 
+	if (hard_udelay) {
+		for_each_cpu(c, &nmi_ipi_pending_mask)
+			do_smp_send_nmi_ipi(c, SMP_OP_NMI_TYPE_HARD);
+
+		do {
+			hard_udelay--;
+			udelay(1);
+			if (cpumask_empty(&nmi_ipi_pending_mask))
+				goto done;
+		} while (hard_udelay);
+	}
+
 	ret = 0; /* Could not gather all CPUs */
 	cpumask_clear(&nmi_ipi_pending_mask);
 done:

index fe9f19e..cde7beb 100644
@@ -343,6 +343,7 @@ static int smp_85xx_kick_cpu(int nr)
 }
 
 struct smp_ops_t smp_85xx_ops = {
+	.cause_nmi_ipi = NULL,
 	.kick_cpu = smp_85xx_kick_cpu,
 	.cpu_bootable = smp_generic_cpu_bootable,
 #ifdef CONFIG_HOTPLUG_CPU

index af09bae..020e84a 100644
@@ -105,6 +105,7 @@ smp_86xx_setup_cpu(int cpu_nr)
 
 
 struct smp_ops_t smp_86xx_ops = {
+	.cause_nmi_ipi = NULL,
 	.message_pass = smp_mpic_message_pass,
 	.probe = smp_mpic_probe,
 	.kick_cpu = smp_86xx_kick_cpu,

index b6c9a0d..1451504 100644
@@ -44,6 +44,7 @@ static void smp_chrp_setup_cpu(int cpu_nr)
 
 /* CHRP with openpic */
 struct smp_ops_t chrp_smp_ops = {
+	.cause_nmi_ipi = NULL,
 	.message_pass = smp_mpic_message_pass,
 	.probe = smp_mpic_probe,
 	.kick_cpu = smp_chrp_kick_cpu,

index c9eb7d6..1d76e15 100644
@@ -446,6 +446,7 @@ void __init smp_psurge_give_timebase(void)
 struct smp_ops_t psurge_smp_ops = {
 	.message_pass	= NULL,	/* Use smp_muxed_ipi_message_pass */
 	.cause_ipi	= smp_psurge_cause_ipi,
+	.cause_nmi_ipi	= NULL,
 	.probe		= smp_psurge_probe,
 	.kick_cpu	= smp_psurge_kick_cpu,
 	.setup_cpu	= smp_psurge_setup_cpu,

index c789258..092ec1f 100644
@@ -244,6 +244,7 @@ static int pnv_cpu_bootable(unsigned int nr)
 static struct smp_ops_t pnv_smp_ops = {
 	.message_pass	= smp_muxed_ipi_message_pass,
 	.cause_ipi	= NULL,	/* Filled at runtime by xics_smp_probe() */
+	.cause_nmi_ipi	= NULL,
 	.probe		= xics_smp_probe,
 	.kick_cpu	= pnv_smp_kick_cpu,
 	.setup_cpu	= pnv_smp_setup_cpu,

index f6f83ae..0f6522c 100644
@@ -209,6 +209,7 @@ static __init void pSeries_smp_probe(void)
 static struct smp_ops_t pseries_smp_ops = {
 	.message_pass	= NULL,	/* Use smp_muxed_ipi_message_pass */
 	.cause_ipi	= NULL,	/* Filled at runtime by pSeries_smp_probe() */
+	.cause_nmi_ipi	= NULL,
 	.probe		= pSeries_smp_probe,
 	.kick_cpu	= smp_pSeries_kick_cpu,
 	.setup_cpu	= smp_setup_cpu,

index 023a462..d1d7fd4 100644
@@ -275,19 +275,22 @@ void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
 
 void system_reset_exception(struct pt_regs *regs)
 {
+	nmi_enter();
+
 	/* See if any machine dependent calls */
 	if (ppc_md.system_reset_exception) {
 		if (ppc_md.system_reset_exception(regs))
-			return;
+			goto done;
 	}
 
 	die("System Reset", regs, SIGABRT);
 
+done:
 	/* Must die if the interrupt is not recoverable */
 	if (!(regs->msr & MSR_RI))
 		panic("Unrecoverable System Reset");
 
-	/* What should we do here? We could issue a shutdown or hard reset. */
+	nmi_exit();
 }
 
 #ifdef CONFIG_PPC64

index 904a677..bb70b26 100644
@@ -386,6 +386,10 @@ int pSeries_system_reset_exception(struct pt_regs *regs)
 		}
 		fwnmi_release_errinfo();
 	}
+
+	if (smp_handle_nmi_ipi(regs))
+		return 1;
+
 	return 0; /* need to perform reset */
 }
 

index 0f6522c..4534c5a 100644
@@ -196,6 +196,16 @@ static void pSeries_cause_ipi_mux(int cpu, unsigned long data)
 		xics_cause_ipi(cpu, data);
 }
 
+static int pseries_cause_nmi_ipi(int cpu, int type)
+{
+	if (type == SMP_OP_NMI_TYPE_HARD) {
+		if (plapr_signal_sys_reset(cpu) == H_SUCCESS)
+			return 1;
+	}
+
+	return 0;
+}
+
 static __init void pSeries_smp_probe(void)
 {
 	xics_smp_probe();

@@ -209,7 +219,7 @@ static __init void pSeries_smp_probe(void)
 static struct smp_ops_t pseries_smp_ops = {
 	.message_pass	= NULL,	/* Use smp_muxed_ipi_message_pass */
 	.cause_ipi	= NULL,	/* Filled at runtime by pSeries_smp_probe() */
-	.cause_nmi_ipi	= NULL,
+	.cause_nmi_ipi	= pseries_cause_nmi_ipi,
 	.probe		= pSeries_smp_probe,
 	.kick_cpu	= smp_pSeries_kick_cpu,
 	.setup_cpu	= smp_setup_cpu,