diff --git a/arch/mips/kernel/smp-mt.c b/arch/mips/kernel/smp-mt.c
index 64b62bdfb4f6..b8fa7ddd78f6 100644
--- a/arch/mips/kernel/smp-mt.c
+++ b/arch/mips/kernel/smp-mt.c
@@ -129,13 +129,13 @@ static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)
 
 static struct irqaction irq_resched = {
 	.handler	= ipi_resched_interrupt,
-	.flags		= IRQF_DISABLED,
+	.flags		= IRQF_DISABLED|IRQF_PERCPU,
 	.name		= "IPI_resched"
 };
 
 static struct irqaction irq_call = {
 	.handler	= ipi_call_interrupt,
-	.flags		= IRQF_DISABLED,
+	.flags		= IRQF_DISABLED|IRQF_PERCPU,
 	.name		= "IPI_call"
 };
 
@@ -275,10 +275,7 @@ void __init plat_prepare_cpus(unsigned int max_cpus)
 	setup_irq(cpu_ipi_resched_irq, &irq_resched);
 	setup_irq(cpu_ipi_call_irq, &irq_call);
 
-	/* need to mark IPI's as IRQ_PER_CPU */
-	irq_desc[cpu_ipi_resched_irq].status |= IRQ_PER_CPU;
 	set_irq_handler(cpu_ipi_resched_irq, handle_percpu_irq);
-	irq_desc[cpu_ipi_call_irq].status |= IRQ_PER_CPU;
 	set_irq_handler(cpu_ipi_call_irq, handle_percpu_irq);
 }
 
@@ -326,8 +323,11 @@ void prom_boot_secondary(int cpu, struct task_struct *idle)
 
 void prom_init_secondary(void)
 {
+	/* Enable per-cpu interrupts */
+
+	/* This is Malta specific: IPI,performance and timer inetrrupts */
 	write_c0_status((read_c0_status() & ~ST0_IM ) |
-	                (STATUSF_IP0 | STATUSF_IP1 | STATUSF_IP7));
+	                (STATUSF_IP0 | STATUSF_IP1 | STATUSF_IP6 | STATUSF_IP7));
 }
 
 void prom_smp_finish(void)
diff --git a/arch/mips/kernel/time.c b/arch/mips/kernel/time.c
index 751b4a18b133..7def1ff3da94 100644
--- a/arch/mips/kernel/time.c
+++ b/arch/mips/kernel/time.c
@@ -199,6 +199,30 @@ int (*perf_irq)(void) = null_perf_irq;
 EXPORT_SYMBOL(null_perf_irq);
 EXPORT_SYMBOL(perf_irq);
 
+/*
+ * Performance counter IRQ or -1 if shared with timer
+ */
+int mipsxx_perfcount_irq;
+EXPORT_SYMBOL(mipsxx_perfcount_irq);
+
+/*
+ * Possibly handle a performance counter interrupt.
+ * Return true if the timer interrupt should not be checked
+ */
+static inline int handle_perf_irq (int r2)
+{
+	/*
+	 * The performance counter overflow interrupt may be shared with the
+	 * timer interrupt (mipsxx_perfcount_irq < 0). If it is and a
+	 * performance counter has overflowed (perf_irq() == IRQ_HANDLED)
+	 * and we can't reliably determine if a counter interrupt has also
+	 * happened (!r2) then don't check for a timer interrupt.
+	 */
+	return (mipsxx_perfcount_irq < 0) &&
+		perf_irq() == IRQ_HANDLED &&
+		!r2;
+}
+
 asmlinkage void ll_timer_interrupt(int irq)
 {
 	int r2 = cpu_has_mips_r2;
@@ -206,19 +230,13 @@ asmlinkage void ll_timer_interrupt(int irq)
 	irq_enter();
 	kstat_this_cpu.irqs[irq]++;
 
-	/*
-	 * Suckage alert:
-	 * Before R2 of the architecture there was no way to see if a
-	 * performance counter interrupt was pending, so we have to run the
-	 * performance counter interrupt handler anyway.
-	 */
-	if (!r2 || (read_c0_cause() & (1 << 26)))
-		if (perf_irq())
-			goto out;
+	if (handle_perf_irq(r2))
+		goto out;
 
-	/* we keep interrupt disabled all the time */
-	if (!r2 || (read_c0_cause() & (1 << 30)))
-		timer_interrupt(irq, NULL);
+	if (r2 && ((read_c0_cause() & (1 << 30)) == 0))
+		goto out;
+
+	timer_interrupt(irq, NULL);
 
 out:
 	irq_exit();
@@ -258,7 +276,7 @@ unsigned int mips_hpt_frequency;
 
 static struct irqaction timer_irqaction = {
 	.handler = timer_interrupt,
-	.flags = IRQF_DISABLED,
+	.flags = IRQF_DISABLED | IRQF_PERCPU,
 	.name = "timer",
 };
 
diff --git a/arch/mips/mips-boards/generic/init.c b/arch/mips/mips-boards/generic/init.c
index 88e9c2a7a2f9..4eabc1eadd23 100644
--- a/arch/mips/mips-boards/generic/init.c
+++ b/arch/mips/mips-boards/generic/init.c
@@ -57,7 +57,8 @@ int *_prom_argv, *_prom_envp;
 
 int init_debug = 0;
 
-unsigned int mips_revision_corid;
+int mips_revision_corid;
+int mips_revision_sconid;
 
 /* Bonito64 system controller register base. */
 unsigned long _pcictrl_bonito;
@@ -275,13 +276,38 @@ void __init prom_init(void)
 		else
 			mips_revision_corid = MIPS_REVISION_CORID_CORE_EMUL_MSC;
 	}
-	switch(mips_revision_corid) {
+
+	mips_revision_sconid = MIPS_REVISION_SCONID;
+	if (mips_revision_sconid == MIPS_REVISION_SCON_OTHER) {
+		switch (mips_revision_corid) {
+		case MIPS_REVISION_CORID_QED_RM5261:
+		case MIPS_REVISION_CORID_CORE_LV:
+		case MIPS_REVISION_CORID_CORE_FPGA:
+		case MIPS_REVISION_CORID_CORE_FPGAR2:
+			mips_revision_sconid = MIPS_REVISION_SCON_GT64120;
+			break;
+		case MIPS_REVISION_CORID_CORE_EMUL_BON:
+		case MIPS_REVISION_CORID_BONITO64:
+		case MIPS_REVISION_CORID_CORE_20K:
+			mips_revision_sconid = MIPS_REVISION_SCON_BONITO;
+			break;
+		case MIPS_REVISION_CORID_CORE_MSC:
+		case MIPS_REVISION_CORID_CORE_FPGA2:
+		case MIPS_REVISION_CORID_CORE_FPGA3:
+		case MIPS_REVISION_CORID_CORE_24K:
+		case MIPS_REVISION_CORID_CORE_EMUL_MSC:
+			mips_revision_sconid = MIPS_REVISION_SCON_SOCIT;
+			break;
+		default:
+			mips_display_message("CC Error");
+			while (1);   /* We die here... */
+		}
+	}
+
+	switch (mips_revision_sconid) {
 		u32 start, map, mask, data;
 
-	case MIPS_REVISION_CORID_QED_RM5261:
-	case MIPS_REVISION_CORID_CORE_LV:
-	case MIPS_REVISION_CORID_CORE_FPGA:
-	case MIPS_REVISION_CORID_CORE_FPGAR2:
+	case MIPS_REVISION_SCON_GT64120:
 		/*
 		 * Setup the North bridge to do Master byte-lane swapping
 		 * when running in bigendian.
@@ -305,9 +331,7 @@ void __init prom_init(void)
 		set_io_port_base(MALTA_GT_PORT_BASE);
 		break;
 
-	case MIPS_REVISION_CORID_CORE_EMUL_BON:
-	case MIPS_REVISION_CORID_BONITO64:
-	case MIPS_REVISION_CORID_CORE_20K:
+	case MIPS_REVISION_SCON_BONITO:
 		_pcictrl_bonito_pcicfg = (unsigned long)ioremap(BONITO_PCICFG_BASE, BONITO_PCICFG_SIZE);
 
 		/*
@@ -334,13 +358,10 @@ void __init prom_init(void)
 		set_io_port_base(MALTA_BONITO_PORT_BASE);
 		break;
 
-	case MIPS_REVISION_CORID_CORE_MSC:
-	case MIPS_REVISION_CORID_CORE_FPGA2:
-	case MIPS_REVISION_CORID_CORE_FPGA3:
-	case MIPS_REVISION_CORID_CORE_24K:
-	case MIPS_REVISION_CORID_CORE_EMUL_MSC:
+	case MIPS_REVISION_SCON_SOCIT:
+	case MIPS_REVISION_SCON_ROCIT:
 		_pcictrl_msc = (unsigned long)ioremap(MIPS_MSC01_PCI_REG_BASE, 0x2000);
-
+	mips_pci_controller:
 		mb();
 		MSC_READ(MSC01_PCI_CFG, data);
 		MSC_WRITE(MSC01_PCI_CFG, data & ~MSC01_PCI_CFG_EN_BIT);
@@ -374,10 +395,15 @@ void __init prom_init(void)
 		set_io_port_base(MALTA_MSC_PORT_BASE);
 		break;
 
+	case MIPS_REVISION_SCON_SOCITSC:
+	case MIPS_REVISION_SCON_SOCITSCP:
+		_pcictrl_msc = (unsigned long)ioremap(MIPS_SOCITSC_PCI_REG_BASE, 0x2000);
+		goto mips_pci_controller;
+
 	default:
-		/* Unknown Core card */
-		mips_display_message("CC Error");
-		while(1);   /* We die here... */
+		/* Unknown system controller */
+		mips_display_message("SC Error");
+		while (1);   /* We die here... */
 	}
 #endif
 	board_nmi_handler_setup = mips_nmi_setup;
diff --git a/arch/mips/mips-boards/generic/pci.c b/arch/mips/mips-boards/generic/pci.c
index f98d60f78658..c9852206890a 100644
--- a/arch/mips/mips-boards/generic/pci.c
+++ b/arch/mips/mips-boards/generic/pci.c
@@ -92,11 +92,8 @@ void __init mips_pcibios_init(void)
 	struct pci_controller *controller;
 	resource_size_t start, end, map, start1, end1, map1, map2, map3, mask;
 
-	switch (mips_revision_corid) {
-	case MIPS_REVISION_CORID_QED_RM5261:
-	case MIPS_REVISION_CORID_CORE_LV:
-	case MIPS_REVISION_CORID_CORE_FPGA:
-	case MIPS_REVISION_CORID_CORE_FPGAR2:
+	switch (mips_revision_sconid) {
+	case MIPS_REVISION_SCON_GT64120:
 		/*
 		 * Due to a bug in the Galileo system controller, we need
 		 * to setup the PCI BAR for the Galileo internal registers.
@@ -161,9 +158,7 @@ void __init mips_pcibios_init(void)
 		controller = &gt64120_controller;
 		break;
 
-	case MIPS_REVISION_CORID_BONITO64:
-	case MIPS_REVISION_CORID_CORE_20K:
-	case MIPS_REVISION_CORID_CORE_EMUL_BON:
+	case MIPS_REVISION_SCON_BONITO:
 		/* Set up resource ranges from the controller's registers.  */
 		map = BONITO_PCIMAP;
 		map1 = (BONITO_PCIMAP & BONITO_PCIMAP_PCIMAP_LO0) >>
@@ -195,11 +190,10 @@ void __init mips_pcibios_init(void)
 		controller = &bonito64_controller;
 		break;
 
-	case MIPS_REVISION_CORID_CORE_MSC:
-	case MIPS_REVISION_CORID_CORE_FPGA2:
-	case MIPS_REVISION_CORID_CORE_FPGA3:
-	case MIPS_REVISION_CORID_CORE_24K:
-	case MIPS_REVISION_CORID_CORE_EMUL_MSC:
+	case MIPS_REVISION_SCON_SOCIT:
+	case MIPS_REVISION_SCON_ROCIT:
+	case MIPS_REVISION_SCON_SOCITSC:
+	case MIPS_REVISION_SCON_SOCITSCP:
 		/* Set up resource ranges from the controller's registers.  */
 		MSC_READ(MSC01_PCI_SC2PMBASL, start);
 		MSC_READ(MSC01_PCI_SC2PMMSKL, mask);
diff --git a/arch/mips/mips-boards/generic/time.c b/arch/mips/mips-boards/generic/time.c
index b41db9e7ab1f..8f1000f51b3d 100644
--- a/arch/mips/mips-boards/generic/time.c
+++ b/arch/mips/mips-boards/generic/time.c
@@ -53,9 +53,8 @@
 
 unsigned long cpu_khz;
 
-#define CPUCTR_IMASKBIT (0x100 << MIPSCPU_INT_CPUCTR)
-
 static int mips_cpu_timer_irq;
+extern int mipsxx_perfcount_irq;
 extern void smtc_timer_broadcast(int);
 
 static void mips_timer_dispatch(void)
@@ -63,6 +62,11 @@ static void mips_timer_dispatch(void)
 	do_IRQ(mips_cpu_timer_irq);
 }
 
+static void mips_perf_dispatch(void)
+{
+	do_IRQ(mipsxx_perfcount_irq);
+}
+
 /*
  * Redeclare until I get around mopping the timer code insanity on MIPS.
  */
@@ -70,6 +74,24 @@ extern int null_perf_irq(void);
 
 extern int (*perf_irq)(void);
 
+/*
+ * Possibly handle a performance counter interrupt.
+ * Return true if the timer interrupt should not be checked
+ */
+static inline int handle_perf_irq (int r2)
+{
+	/*
+	 * The performance counter overflow interrupt may be shared with the
+	 * timer interrupt (mipsxx_perfcount_irq < 0). If it is and a
+	 * performance counter has overflowed (perf_irq() == IRQ_HANDLED)
+	 * and we can't reliably determine if a counter interrupt has also
+	 * happened (!r2) then don't check for a timer interrupt.
+	 */
+	return (mipsxx_perfcount_irq < 0) &&
+		perf_irq() == IRQ_HANDLED &&
+		!r2;
+}
+
 irqreturn_t mips_timer_interrupt(int irq, void *dev_id)
 {
 	int cpu = smp_processor_id();
@@ -92,8 +114,7 @@ irqreturn_t mips_timer_interrupt(int irq, void *dev_id)
 	 * We could be here due to timer interrupt,
 	 * perf counter overflow, or both.
 	 */
-	if (read_c0_cause() & (1 << 26))
-		perf_irq();
+	(void) handle_perf_irq(1);
 
 	if (read_c0_cause() & (1 << 30)) {
 		/*
@@ -115,19 +136,19 @@ irqreturn_t mips_timer_interrupt(int irq, void *dev_id)
 #else /* CONFIG_MIPS_MT_SMTC */
 	int r2 = cpu_has_mips_r2;
 
+	if (handle_perf_irq(r2))
+		goto out;
+
+	if (r2 && ((read_c0_cause() & (1 << 30)) == 0))
+		goto out;
+
 	if (cpu == 0) {
 		/*
 		 * CPU 0 handles the global timer interrupt job and process
 		 * accounting resets count/compare registers to trigger next
 		 * timer int.
 		 */
-		if (!r2 || (read_c0_cause() & (1 << 26)))
-			if (perf_irq())
-				goto out;
-
-		/* we keep interrupt disabled all the time */
-		if (!r2 || (read_c0_cause() & (1 << 30)))
-			timer_interrupt(irq, NULL);
+		timer_interrupt(irq, NULL);
 	} else {
 		/* Everyone else needs to reset the timer int here as
 		   ll_local_timer_interrupt doesn't */
@@ -225,35 +246,85 @@ void __init mips_time_init(void)
 	mips_scroll_message();
 }
 
+irqreturn_t mips_perf_interrupt(int irq, void *dev_id)
+{
+	return perf_irq();
+}
+
+static struct irqaction perf_irqaction = {
+	.handler = mips_perf_interrupt,
+	.flags = IRQF_DISABLED | IRQF_PERCPU,
+	.name = "performance",
+};
+
+void __init plat_perf_setup(struct irqaction *irq)
+{
+	int hwint = 0;
+	mipsxx_perfcount_irq = -1;
+
+#ifdef MSC01E_INT_BASE
+	if (cpu_has_veic) {
+		set_vi_handler (MSC01E_INT_PERFCTR, mips_perf_dispatch);
+		mipsxx_perfcount_irq = MSC01E_INT_BASE + MSC01E_INT_PERFCTR;
+	} else
+#endif
+	if (cpu_has_mips_r2) {
+		/*
+		 * Read IntCtl.IPPCI to determine the performance
+		 * counter interrupt
+		 */
+		hwint = (read_c0_intctl () >> 26) & 7;
+		if (hwint != MIPSCPU_INT_CPUCTR) {
+			if (cpu_has_vint)
+				set_vi_handler (hwint, mips_perf_dispatch);
+			mipsxx_perfcount_irq = MIPSCPU_INT_BASE + hwint;
+		}
+	}
+	if (mipsxx_perfcount_irq >= 0) {
+#ifdef CONFIG_MIPS_MT_SMTC
+		setup_irq_smtc(mipsxx_perfcount_irq, irq, 0x100 << hwint);
+#else
+		setup_irq(mipsxx_perfcount_irq, irq);
+#endif /* CONFIG_MIPS_MT_SMTC */
+#ifdef CONFIG_SMP
+		set_irq_handler(mipsxx_perfcount_irq, handle_percpu_irq);
+#endif
+	}
+}
+
 void __init plat_timer_setup(struct irqaction *irq)
 {
+	int hwint = 0;
 #ifdef MSC01E_INT_BASE
 	if (cpu_has_veic) {
 		set_vi_handler (MSC01E_INT_CPUCTR, mips_timer_dispatch);
 		mips_cpu_timer_irq = MSC01E_INT_BASE + MSC01E_INT_CPUCTR;
-	} else
+	}
+	else
 #endif
 	{
+		if (cpu_has_mips_r2)
+			/*
+			 * Read IntCtl.IPTI to determine the timer interrupt
+			 */
+			hwint = (read_c0_intctl () >> 29) & 7;
+		else
+			hwint = MIPSCPU_INT_CPUCTR;
 		if (cpu_has_vint)
-			set_vi_handler (MIPSCPU_INT_CPUCTR, mips_timer_dispatch);
-		mips_cpu_timer_irq = MIPSCPU_INT_BASE + MIPSCPU_INT_CPUCTR;
+			set_vi_handler (hwint, mips_timer_dispatch);
+		mips_cpu_timer_irq = MIPSCPU_INT_BASE + hwint;
 	}
 
-
 	/* we are using the cpu counter for timer interrupts */
 	irq->handler = mips_timer_interrupt;	/* we use our own handler */
 #ifdef CONFIG_MIPS_MT_SMTC
-	setup_irq_smtc(mips_cpu_timer_irq, irq, CPUCTR_IMASKBIT);
+	setup_irq_smtc(mips_cpu_timer_irq, irq, 0x100 << hwint);
 #else
 	setup_irq(mips_cpu_timer_irq, irq);
 #endif /* CONFIG_MIPS_MT_SMTC */
-
 #ifdef CONFIG_SMP
-	/* irq_desc(riptor) is a global resource, when the interrupt overlaps
-	   on seperate cpu's the first one tries to handle the second interrupt.
-	   The effect is that the int remains disabled on the second cpu.
-	   Mark the interrupt with IRQ_PER_CPU to avoid any confusion */
-	irq_desc[mips_cpu_timer_irq].status |= IRQ_PER_CPU;
 	set_irq_handler(mips_cpu_timer_irq, handle_percpu_irq);
 #endif
+
+	plat_perf_setup(&perf_irqaction);
 }
diff --git a/arch/mips/mips-boards/malta/malta_int.c b/arch/mips/mips-boards/malta/malta_int.c
index 1cd830e3d933..1668cc21d5b5 100644
--- a/arch/mips/mips-boards/malta/malta_int.c
+++ b/arch/mips/mips-boards/malta/malta_int.c
@@ -53,25 +53,19 @@ static inline int mips_pcibios_iack(void)
 	 * Determine highest priority pending interrupt by performing
 	 * a PCI Interrupt Acknowledge cycle.
 	 */
-	switch(mips_revision_corid) {
-	case MIPS_REVISION_CORID_CORE_MSC:
-	case MIPS_REVISION_CORID_CORE_FPGA2:
-	case MIPS_REVISION_CORID_CORE_FPGA3:
-	case MIPS_REVISION_CORID_CORE_24K:
-	case MIPS_REVISION_CORID_CORE_EMUL_MSC:
+	switch (mips_revision_sconid) {
+	case MIPS_REVISION_SCON_SOCIT:
+	case MIPS_REVISION_SCON_ROCIT:
+	case MIPS_REVISION_SCON_SOCITSC:
+	case MIPS_REVISION_SCON_SOCITSCP:
 	        MSC_READ(MSC01_PCI_IACK, irq);
 		irq &= 0xff;
 		break;
-	case MIPS_REVISION_CORID_QED_RM5261:
-	case MIPS_REVISION_CORID_CORE_LV:
-	case MIPS_REVISION_CORID_CORE_FPGA:
-	case MIPS_REVISION_CORID_CORE_FPGAR2:
+	case MIPS_REVISION_SCON_GT64120:
 		irq = GT_READ(GT_PCI0_IACK_OFS);
 		irq &= 0xff;
 		break;
-	case MIPS_REVISION_CORID_BONITO64:
-	case MIPS_REVISION_CORID_CORE_20K:
-	case MIPS_REVISION_CORID_CORE_EMUL_BON:
+	case MIPS_REVISION_SCON_BONITO:
 		/* The following will generate a PCI IACK cycle on the
 		 * Bonito controller. It's a little bit kludgy, but it
 		 * was the easiest way to implement it in hardware at
@@ -89,7 +83,7 @@ static inline int mips_pcibios_iack(void)
 		BONITO_PCIMAP_CFG = 0;
 		break;
 	default:
-	        printk("Unknown Core card, don't know the system controller.\n");
+	        printk("Unknown system controller.\n");
 		return -1;
 	}
 	return irq;
@@ -144,27 +138,21 @@ static void corehi_irqdispatch(void)
 	   Do it for the others too.
 	*/
 
-        switch(mips_revision_corid) {
-        case MIPS_REVISION_CORID_CORE_MSC:
-        case MIPS_REVISION_CORID_CORE_FPGA2:
-        case MIPS_REVISION_CORID_CORE_FPGA3:
-        case MIPS_REVISION_CORID_CORE_24K:
-        case MIPS_REVISION_CORID_CORE_EMUL_MSC:
+	switch (mips_revision_sconid) {
+        case MIPS_REVISION_SCON_SOCIT:
+	case MIPS_REVISION_SCON_ROCIT:
+	case MIPS_REVISION_SCON_SOCITSC:
+	case MIPS_REVISION_SCON_SOCITSCP:
                 ll_msc_irq();
                 break;
-        case MIPS_REVISION_CORID_QED_RM5261:
-        case MIPS_REVISION_CORID_CORE_LV:
-        case MIPS_REVISION_CORID_CORE_FPGA:
-        case MIPS_REVISION_CORID_CORE_FPGAR2:
+        case MIPS_REVISION_SCON_GT64120:
                 intrcause = GT_READ(GT_INTRCAUSE_OFS);
                 datalo = GT_READ(GT_CPUERR_ADDRLO_OFS);
                 datahi = GT_READ(GT_CPUERR_ADDRHI_OFS);
                 printk("GT_INTRCAUSE = %08x\n", intrcause);
                 printk("GT_CPUERR_ADDR = %02x%08x\n", datahi, datalo);
                 break;
-        case MIPS_REVISION_CORID_BONITO64:
-        case MIPS_REVISION_CORID_CORE_20K:
-        case MIPS_REVISION_CORID_CORE_EMUL_BON:
+        case MIPS_REVISION_SCON_BONITO:
                 pcibadaddr = BONITO_PCIBADADDR;
                 pcimstat = BONITO_PCIMSTAT;
                 intisr = BONITO_INTISR;
diff --git a/arch/mips/mips-boards/malta/malta_setup.c b/arch/mips/mips-boards/malta/malta_setup.c
index c14b7bf89950..8f1b78dfd89f 100644
--- a/arch/mips/mips-boards/malta/malta_setup.c
+++ b/arch/mips/mips-boards/malta/malta_setup.c
@@ -103,9 +103,7 @@ void __init plat_mem_setup(void)
 	kgdb_config ();
 #endif
 
-	if ((mips_revision_corid == MIPS_REVISION_CORID_BONITO64) ||
-	    (mips_revision_corid == MIPS_REVISION_CORID_CORE_20K) ||
-	    (mips_revision_corid == MIPS_REVISION_CORID_CORE_EMUL_BON)) {
+	if (mips_revision_sconid == MIPS_REVISION_SCON_BONITO) {
 		char *argptr;
 
 		argptr = prom_getcmdline();
diff --git a/arch/mips/oprofile/op_model_mipsxx.c b/arch/mips/oprofile/op_model_mipsxx.c
index 4f94fa261aae..1ea5c9c1010b 100644
--- a/arch/mips/oprofile/op_model_mipsxx.c
+++ b/arch/mips/oprofile/op_model_mipsxx.c
@@ -177,7 +177,10 @@ static int mipsxx_perfcount_handler(void)
 	unsigned int counters = op_model_mipsxx_ops.num_counters;
 	unsigned int control;
 	unsigned int counter;
-	int handled = 0;
+	int handled = IRQ_NONE;
+
+	if (cpu_has_mips_r2 && !(read_c0_cause() & (1 << 26)))
+		return handled;
 
 	switch (counters) {
 #define HANDLE_COUNTER(n)						\
@@ -188,7 +191,7 @@ static int mipsxx_perfcount_handler(void)
 		    (counter & M_COUNTER_OVERFLOW)) {			\
 			oprofile_add_sample(get_irq_regs(), n);		\
 			w_c0_perfcntr ## n(reg.counter[n]);		\
-			handled = 1;					\
+			handled = IRQ_HANDLED;				\
 		}
 	HANDLE_COUNTER(3)
 	HANDLE_COUNTER(2)
diff --git a/include/asm-mips/mips-boards/generic.h b/include/asm-mips/mips-boards/generic.h
index b98f1658cfd0..c8ebcc3e1267 100644
--- a/include/asm-mips/mips-boards/generic.h
+++ b/include/asm-mips/mips-boards/generic.h
@@ -73,12 +73,28 @@
  *  CoreEMUL with   Bonito   System Controller is treated like a Core20K
  *  CoreEMUL with SOC-it 101 System Controller is treated like a CoreMSC
  */
-#define MIPS_REVISION_CORID_CORE_EMUL_BON  0x63
-#define MIPS_REVISION_CORID_CORE_EMUL_MSC  0x65
+#define MIPS_REVISION_CORID_CORE_EMUL_BON  -1
+#define MIPS_REVISION_CORID_CORE_EMUL_MSC  -2
 
 #define MIPS_REVISION_CORID (((*(volatile u32 *)ioremap(MIPS_REVISION_REG, 4)) >> 10) & 0x3f)
 
-extern unsigned int mips_revision_corid;
+extern int mips_revision_corid;
+
+#define MIPS_REVISION_SCON_OTHER	   0
+#define MIPS_REVISION_SCON_SOCITSC	   1
+#define MIPS_REVISION_SCON_SOCITSCP	   2
+
+/* Artificial SCON defines for MIPS_REVISION_SCON_OTHER */
+#define MIPS_REVISION_SCON_UNKNOWN	   -1
+#define MIPS_REVISION_SCON_GT64120	   -2
+#define MIPS_REVISION_SCON_BONITO	   -3
+#define MIPS_REVISION_SCON_BRTL		   -4
+#define MIPS_REVISION_SCON_SOCIT	   -5
+#define MIPS_REVISION_SCON_ROCIT	   -6
+
+#define MIPS_REVISION_SCONID (((*(volatile u32 *)ioremap(MIPS_REVISION_REG, 4)) >> 24) & 0xff)
+
+extern int mips_revision_sconid;
 
 #ifdef CONFIG_PCI
 extern void mips_pcibios_init(void);
diff --git a/include/asm-mips/mips-boards/msc01_pci.h b/include/asm-mips/mips-boards/msc01_pci.h
index 8eaefb837b9d..e036b7dd6deb 100644
--- a/include/asm-mips/mips-boards/msc01_pci.h
+++ b/include/asm-mips/mips-boards/msc01_pci.h
@@ -208,6 +208,7 @@
  * latter, they should be moved elsewhere.
  */
 #define MIPS_MSC01_PCI_REG_BASE		0x1bd00000
+#define MIPS_SOCITSC_PCI_REG_BASE	0x1ff10000
 
 extern unsigned long _pcictrl_msc;