Merge branch 'linus' into perfcounters/urgent

Merge reason: this branch was on a .30-ish base before, update
              it to an almost-.31-rc2 upstream base to pick up fixes.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

51 files changed, 490 insertions, 24 deletions

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index b29f028..8c4be1f 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -601,6 +601,7 @@ config CAVIUM_OCTEON_SIMULATOR
 	select SYS_SUPPORTS_64BIT_KERNEL
 	select SYS_SUPPORTS_BIG_ENDIAN
 	select SYS_SUPPORTS_HIGHMEM
+	select SYS_SUPPORTS_HOTPLUG_CPU
 	select SYS_HAS_CPU_CAVIUM_OCTEON
 	help
 	  The Octeon simulator is software performance model of the Cavium
@@ -615,6 +616,7 @@ config CAVIUM_OCTEON_REFERENCE_BOARD
 	select SYS_SUPPORTS_64BIT_KERNEL
 	select SYS_SUPPORTS_BIG_ENDIAN
 	select SYS_SUPPORTS_HIGHMEM
+	select SYS_SUPPORTS_HOTPLUG_CPU
 	select SYS_HAS_EARLY_PRINTK
 	select SYS_HAS_CPU_CAVIUM_OCTEON
 	select SWAP_IO_SPACE
@@ -784,8 +786,17 @@ config SYS_HAS_EARLY_PRINTK
 	bool
 
 config HOTPLUG_CPU
+	bool "Support for hot-pluggable CPUs"
+	depends on SMP && HOTPLUG && SYS_SUPPORTS_HOTPLUG_CPU
+	help
+	  Say Y here to allow turning CPUs off and on. CPUs can be
+	  controlled through /sys/devices/system/cpu.
+	  (Note: power management support will enable this option
+	    automatically on SMP systems. )
+	  Say N if you want to disable CPU hotplug.
+
+config SYS_SUPPORTS_HOTPLUG_CPU
 	bool
-	default n
 
 config I8259
 	bool
@@ -2136,11 +2147,11 @@ menu "Power management options"
 
 config ARCH_HIBERNATION_POSSIBLE
 	def_bool y
-	depends on !SMP
+	depends on SYS_SUPPORTS_HOTPLUG_CPU
 
 config ARCH_SUSPEND_POSSIBLE
 	def_bool y
-	depends on !SMP
+	depends on SYS_SUPPORTS_HOTPLUG_CPU
 
 source "kernel/power/Kconfig"
 
diff --git a/arch/mips/cavium-octeon/octeon-irq.c b/arch/mips/cavium-octeon/octeon-irq.c
index 8dfa009..384f184 100644
--- a/arch/mips/cavium-octeon/octeon-irq.c
+++ b/arch/mips/cavium-octeon/octeon-irq.c
@@ -7,7 +7,7 @@
  */
 #include <linux/irq.h>
 #include <linux/interrupt.h>
-#include <linux/hardirq.h>
+#include <linux/smp.h>
 
 #include <asm/octeon/octeon.h>
 #include <asm/octeon/cvmx-pexp-defs.h>
@@ -501,3 +501,62 @@ asmlinkage void plat_irq_dispatch(void)
 		}
 	}
 }
+
+#ifdef CONFIG_HOTPLUG_CPU
+static int is_irq_enabled_on_cpu(unsigned int irq, unsigned int cpu)
+{
+       unsigned int isset;
+#ifdef CONFIG_SMP
+       int coreid = cpu_logical_map(cpu);
+#else
+	int coreid = cvmx_get_core_num();
+#endif
+	int bit = (irq < OCTEON_IRQ_WDOG0) ?
+		irq - OCTEON_IRQ_WORKQ0 : irq - OCTEON_IRQ_WDOG0;
+       if (irq < 64) {
+		isset = (cvmx_read_csr(CVMX_CIU_INTX_EN0(coreid * 2)) &
+			(1ull << bit)) >> bit;
+       } else {
+	       isset = (cvmx_read_csr(CVMX_CIU_INTX_EN1(coreid * 2 + 1)) &
+			(1ull << bit)) >> bit;
+       }
+       return isset;
+}
+
+void fixup_irqs(void)
+{
+       int irq;
+
+	for (irq = OCTEON_IRQ_SW0; irq <= OCTEON_IRQ_TIMER; irq++)
+		octeon_irq_core_disable_local(irq);
+
+	for (irq = OCTEON_IRQ_WORKQ0; irq <= OCTEON_IRQ_GPIO15; irq++) {
+		if (is_irq_enabled_on_cpu(irq, smp_processor_id())) {
+			/* ciu irq migrates to next cpu */
+			octeon_irq_chip_ciu0.disable(irq);
+			octeon_irq_ciu0_set_affinity(irq, &cpu_online_map);
+		}
+	}
+
+#if 0
+	for (irq = OCTEON_IRQ_MBOX0; irq <= OCTEON_IRQ_MBOX1; irq++)
+		octeon_irq_mailbox_mask(irq);
+#endif
+	for (irq = OCTEON_IRQ_UART0; irq <= OCTEON_IRQ_BOOTDMA; irq++) {
+		if (is_irq_enabled_on_cpu(irq, smp_processor_id())) {
+			/* ciu irq migrates to next cpu */
+			octeon_irq_chip_ciu0.disable(irq);
+			octeon_irq_ciu0_set_affinity(irq, &cpu_online_map);
+		}
+	}
+
+	for (irq = OCTEON_IRQ_UART2; irq <= OCTEON_IRQ_RESERVED135; irq++) {
+		if (is_irq_enabled_on_cpu(irq, smp_processor_id())) {
+			/* ciu irq migrates to next cpu */
+			octeon_irq_chip_ciu1.disable(irq);
+			octeon_irq_ciu1_set_affinity(irq, &cpu_online_map);
+		}
+	}
+}
+
+#endif /* CONFIG_HOTPLUG_CPU */
diff --git a/arch/mips/cavium-octeon/octeon_boot.h b/arch/mips/cavium-octeon/octeon_boot.h
new file mode 100644
index 0000000..0f7f84a
--- /dev/null
+++ b/arch/mips/cavium-octeon/octeon_boot.h
@@ -0,0 +1,70 @@
+/*
+ * (C) Copyright 2004, 2005 Cavium Networks
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#ifndef __OCTEON_BOOT_H__
+#define __OCTEON_BOOT_H__
+
+#include <linux/types.h>
+
+struct boot_init_vector {
+	uint32_t stack_addr;
+	uint32_t code_addr;
+	uint32_t app_start_func_addr;
+	uint32_t k0_val;
+	uint32_t flags;
+	uint32_t boot_info_addr;
+	uint32_t pad;
+	uint32_t pad2;
+};
+
+/* similar to bootloader's linux_app_boot_info but without global data */
+struct linux_app_boot_info {
+	uint32_t labi_signature;
+	uint32_t start_core0_addr;
+	uint32_t avail_coremask;
+	uint32_t pci_console_active;
+	uint32_t icache_prefetch_disable;
+	uint32_t InitTLBStart_addr;
+	uint32_t start_app_addr;
+	uint32_t cur_exception_base;
+	uint32_t no_mark_private_data;
+	uint32_t compact_flash_common_base_addr;
+	uint32_t compact_flash_attribute_base_addr;
+	uint32_t led_display_base_addr;
+};
+
+/* If not to copy a lot of bootloader's structures
+   here is only offset of requested member */
+#define AVAIL_COREMASK_OFFSET_IN_LINUX_APP_BOOT_BLOCK    0x765c
+
+/* hardcoded in bootloader */
+#define  LABI_ADDR_IN_BOOTLOADER                         0x700
+
+#define LINUX_APP_BOOT_BLOCK_NAME "linux-app-boot"
+
+#define LABI_SIGNATURE 0xAABBCCDD
+
+/*  from uboot-headers/octeon_mem_map.h */
+#define EXCEPTION_BASE_INCR     (4 * 1024)
+			       /* Increment size for exception base addresses (4k minimum) */
+#define EXCEPTION_BASE_BASE     0
+#define BOOTLOADER_PRIV_DATA_BASE       (EXCEPTION_BASE_BASE + 0x800)
+#define BOOTLOADER_BOOT_VECTOR          (BOOTLOADER_PRIV_DATA_BASE)
+
+#endif /* __OCTEON_BOOT_H__ */
diff --git a/arch/mips/cavium-octeon/setup.c b/arch/mips/cavium-octeon/setup.c
index 5f4e49b..da55924 100644
--- a/arch/mips/cavium-octeon/setup.c
+++ b/arch/mips/cavium-octeon/setup.c
@@ -13,6 +13,7 @@
 #include <linux/io.h>
 #include <linux/irq.h>
 #include <linux/serial.h>
+#include <linux/smp.h>
 #include <linux/types.h>
 #include <linux/string.h>	/* for memset */
 #include <linux/tty.h>
diff --git a/arch/mips/cavium-octeon/smp.c b/arch/mips/cavium-octeon/smp.c
index 24e0ad6..0b891a9 100644
--- a/arch/mips/cavium-octeon/smp.c
+++ b/arch/mips/cavium-octeon/smp.c
@@ -5,6 +5,7 @@
  *
  * Copyright (C) 2004-2008 Cavium Networks
  */
+#include <linux/cpu.h>
 #include <linux/init.h>
 #include <linux/delay.h>
 #include <linux/smp.h>
@@ -19,10 +20,16 @@
 
 #include <asm/octeon/octeon.h>
 
+#include "octeon_boot.h"
+
 volatile unsigned long octeon_processor_boot = 0xff;
 volatile unsigned long octeon_processor_sp;
 volatile unsigned long octeon_processor_gp;
 
+#ifdef CONFIG_HOTPLUG_CPU
+static unsigned int InitTLBStart_addr;
+#endif
+
 static irqreturn_t mailbox_interrupt(int irq, void *dev_id)
 {
 	const int coreid = cvmx_get_core_num();
@@ -67,8 +74,28 @@ static inline void octeon_send_ipi_mask(cpumask_t mask, unsigned int action)
 }
 
 /**
- * Detect available CPUs, populate phys_cpu_present_map
+ * Detect available CPUs, populate cpu_possible_map
  */
+static void octeon_smp_hotplug_setup(void)
+{
+#ifdef CONFIG_HOTPLUG_CPU
+	uint32_t labi_signature;
+
+	labi_signature =
+		cvmx_read64_uint32(CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS,
+					LABI_ADDR_IN_BOOTLOADER +
+					offsetof(struct linux_app_boot_info,
+						    labi_signature)));
+	if (labi_signature != LABI_SIGNATURE)
+		pr_err("The bootloader version on this board is incorrect\n");
+	InitTLBStart_addr =
+		cvmx_read64_uint32(CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS,
+				   LABI_ADDR_IN_BOOTLOADER +
+					   offsetof(struct linux_app_boot_info,
+						    InitTLBStart_addr)));
+#endif
+}
+
 static void octeon_smp_setup(void)
 {
 	const int coreid = cvmx_get_core_num();
@@ -91,6 +118,9 @@ static void octeon_smp_setup(void)
 			cpus++;
 		}
 	}
+	cpu_present_map = cpu_possible_map;
+
+	octeon_smp_hotplug_setup();
 }
 
 /**
@@ -128,6 +158,17 @@ static void octeon_init_secondary(void)
 	const int coreid = cvmx_get_core_num();
 	union cvmx_ciu_intx_sum0 interrupt_enable;
 
+#ifdef CONFIG_HOTPLUG_CPU
+	unsigned int cur_exception_base;
+
+	cur_exception_base = cvmx_read64_uint32(
+		CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS,
+			     LABI_ADDR_IN_BOOTLOADER +
+			     offsetof(struct linux_app_boot_info,
+				      cur_exception_base)));
+	/* cur_exception_base is incremented in bootloader after setting */
+	write_c0_ebase((unsigned int)(cur_exception_base - EXCEPTION_BASE_INCR));
+#endif
 	octeon_check_cpu_bist();
 	octeon_init_cvmcount();
 	/*
@@ -199,6 +240,193 @@ static void octeon_cpus_done(void)
 #endif
 }
 
+#ifdef CONFIG_HOTPLUG_CPU
+
+/* State of each CPU. */
+DEFINE_PER_CPU(int, cpu_state);
+
+extern void fixup_irqs(void);
+
+static DEFINE_SPINLOCK(smp_reserve_lock);
+
+static int octeon_cpu_disable(void)
+{
+	unsigned int cpu = smp_processor_id();
+
+	if (cpu == 0)
+		return -EBUSY;
+
+	spin_lock(&smp_reserve_lock);
+
+	cpu_clear(cpu, cpu_online_map);
+	cpu_clear(cpu, cpu_callin_map);
+	local_irq_disable();
+	fixup_irqs();
+	local_irq_enable();
+
+	flush_cache_all();
+	local_flush_tlb_all();
+
+	spin_unlock(&smp_reserve_lock);
+
+	return 0;
+}
+
+static void octeon_cpu_die(unsigned int cpu)
+{
+	int coreid = cpu_logical_map(cpu);
+	uint32_t avail_coremask;
+	struct cvmx_bootmem_named_block_desc *block_desc;
+
+#ifdef CONFIG_CAVIUM_OCTEON_WATCHDOG
+	/* Disable the watchdog */
+	cvmx_ciu_wdogx_t ciu_wdog;
+	ciu_wdog.u64 = cvmx_read_csr(CVMX_CIU_WDOGX(cpu));
+	ciu_wdog.s.mode = 0;
+	cvmx_write_csr(CVMX_CIU_WDOGX(cpu), ciu_wdog.u64);
+#endif
+
+	while (per_cpu(cpu_state, cpu) != CPU_DEAD)
+		cpu_relax();
+
+	/*
+	 * This is a bit complicated strategics of getting/settig available
+	 * cores mask, copied from bootloader
+	 */
+	/* LINUX_APP_BOOT_BLOCK is initialized in bootoct binary */
+	block_desc = cvmx_bootmem_find_named_block(LINUX_APP_BOOT_BLOCK_NAME);
+
+	if (!block_desc) {
+		avail_coremask =
+			cvmx_read64_uint32(CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS,
+						   LABI_ADDR_IN_BOOTLOADER +
+						   offsetof
+						   (struct linux_app_boot_info,
+						    avail_coremask)));
+	} else {		       /* alternative, already initialized */
+	       avail_coremask =
+		   cvmx_read64_uint32(CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS,
+						   block_desc->base_addr +
+						  AVAIL_COREMASK_OFFSET_IN_LINUX_APP_BOOT_BLOCK));
+	}
+
+	avail_coremask |= 1 << coreid;
+
+	/* Setting avail_coremask for bootoct binary */
+	if (!block_desc) {
+		cvmx_write64_uint32(CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS,
+						LABI_ADDR_IN_BOOTLOADER +
+						offsetof(struct linux_app_boot_info,
+							 avail_coremask)),
+				   avail_coremask);
+	} else {
+		cvmx_write64_uint32(CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS,
+						block_desc->base_addr +
+						AVAIL_COREMASK_OFFSET_IN_LINUX_APP_BOOT_BLOCK),
+				   avail_coremask);
+	}
+
+	pr_info("Reset core %d. Available Coremask = %x \n", coreid,
+		avail_coremask);
+	cvmx_write_csr(CVMX_CIU_PP_RST, 1 << coreid);
+	cvmx_write_csr(CVMX_CIU_PP_RST, 0);
+}
+
+void play_dead(void)
+{
+	int coreid = cvmx_get_core_num();
+
+	idle_task_exit();
+	octeon_processor_boot = 0xff;
+	per_cpu(cpu_state, coreid) = CPU_DEAD;
+
+	while (1)	/* core will be reset here */
+		;
+}
+
+extern void kernel_entry(unsigned long arg1, ...);
+
+static void start_after_reset(void)
+{
+	kernel_entry(0, 0, 0);  /* set a2 = 0 for secondary core */
+}
+
+int octeon_update_boot_vector(unsigned int cpu)
+{
+
+	int coreid = cpu_logical_map(cpu);
+	unsigned int avail_coremask;
+	struct cvmx_bootmem_named_block_desc *block_desc;
+	struct boot_init_vector *boot_vect =
+		(struct boot_init_vector *) cvmx_phys_to_ptr(0x0 +
+						  BOOTLOADER_BOOT_VECTOR);
+
+	block_desc = cvmx_bootmem_find_named_block(LINUX_APP_BOOT_BLOCK_NAME);
+
+	if (!block_desc) {
+		avail_coremask =
+			cvmx_read64_uint32(CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS,
+					   LABI_ADDR_IN_BOOTLOADER +
+						offsetof(struct linux_app_boot_info,
+						avail_coremask)));
+	} else {		       /* alternative, already initialized */
+	       avail_coremask =
+		   cvmx_read64_uint32(CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS,
+						   block_desc->base_addr +
+						   AVAIL_COREMASK_OFFSET_IN_LINUX_APP_BOOT_BLOCK));
+	}
+
+	if (!(avail_coremask & (1 << coreid))) {
+		/* core not available, assume, that catched by simple-executive */
+		cvmx_write_csr(CVMX_CIU_PP_RST, 1 << coreid);
+		cvmx_write_csr(CVMX_CIU_PP_RST, 0);
+	}
+
+	boot_vect[coreid].app_start_func_addr =
+		(uint32_t) (unsigned long) start_after_reset;
+	boot_vect[coreid].code_addr = InitTLBStart_addr;
+
+	CVMX_SYNC;
+
+	cvmx_write_csr(CVMX_CIU_NMI, (1 << coreid) & avail_coremask);
+
+	return 0;
+}
+
+static int __cpuinit octeon_cpu_callback(struct notifier_block *nfb,
+	unsigned long action, void *hcpu)
+{
+	unsigned int cpu = (unsigned long)hcpu;
+
+	switch (action) {
+	case CPU_UP_PREPARE:
+		octeon_update_boot_vector(cpu);
+		break;
+	case CPU_ONLINE:
+		pr_info("Cpu %d online\n", cpu);
+		break;
+	case CPU_DEAD:
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block __cpuinitdata octeon_cpu_notifier = {
+	.notifier_call = octeon_cpu_callback,
+};
+
+static int __cpuinit register_cavium_notifier(void)
+{
+	register_hotcpu_notifier(&octeon_cpu_notifier);
+
+	return 0;
+}
+
+late_initcall(register_cavium_notifier);
+
+#endif  /* CONFIG_HOTPLUG_CPU */
+
 struct plat_smp_ops octeon_smp_ops = {
 	.send_ipi_single	= octeon_send_ipi_single,
 	.send_ipi_mask		= octeon_send_ipi_mask,
@@ -208,4 +436,8 @@ struct plat_smp_ops octeon_smp_ops = {
 	.boot_secondary		= octeon_boot_secondary,
 	.smp_setup		= octeon_smp_setup,
 	.prepare_cpus		= octeon_prepare_cpus,
+#ifdef CONFIG_HOTPLUG_CPU
+	.cpu_disable		= octeon_cpu_disable,
+	.cpu_die		= octeon_cpu_die,
+#endif
 };
diff --git a/arch/mips/include/asm/bug.h b/arch/mips/include/asm/bug.h
index 08ea468..6cf29c2 100644
--- a/arch/mips/include/asm/bug.h
+++ b/arch/mips/include/asm/bug.h
@@ -1,6 +1,7 @@
 #ifndef __ASM_BUG_H
 #define __ASM_BUG_H
 
+#include <linux/compiler.h>
 #include <asm/sgidefs.h>
 
 #ifdef CONFIG_BUG
diff --git a/arch/mips/include/asm/bugs.h b/arch/mips/include/asm/bugs.h
index 9dc10df..b160a70 100644
--- a/arch/mips/include/asm/bugs.h
+++ b/arch/mips/include/asm/bugs.h
@@ -11,6 +11,7 @@
 
 #include <linux/bug.h>
 #include <linux/delay.h>
+#include <linux/smp.h>
 
 #include <asm/cpu.h>
 #include <asm/cpu-info.h>
diff --git a/arch/mips/include/asm/irq.h b/arch/mips/include/asm/irq.h
index 4f1eed1..09b08d0 100644
--- a/arch/mips/include/asm/irq.h
+++ b/arch/mips/include/asm/irq.h
@@ -10,6 +10,7 @@
 #define _ASM_IRQ_H
 
 #include <linux/linkage.h>
+#include <linux/smp.h>
 
 #include <asm/mipsmtregs.h>
 
diff --git a/arch/mips/include/asm/mmu_context.h b/arch/mips/include/asm/mmu_context.h
index d7f3eb0..d3bea88 100644
--- a/arch/mips/include/asm/mmu_context.h
+++ b/arch/mips/include/asm/mmu_context.h
@@ -13,6 +13,7 @@
 
 #include <linux/errno.h>
 #include <linux/sched.h>
+#include <linux/smp.h>
 #include <linux/slab.h>
 #include <asm/cacheflush.h>
 #include <asm/tlbflush.h>
diff --git a/arch/mips/include/asm/smp-ops.h b/arch/mips/include/asm/smp-ops.h
index 64ffc02..fd54554 100644
--- a/arch/mips/include/asm/smp-ops.h
+++ b/arch/mips/include/asm/smp-ops.h
@@ -26,6 +26,10 @@ struct plat_smp_ops {
 	void (*boot_secondary)(int cpu, struct task_struct *idle);
 	void (*smp_setup)(void);
 	void (*prepare_cpus)(unsigned int max_cpus);
+#ifdef CONFIG_HOTPLUG_CPU
+	int (*cpu_disable)(void);
+	void (*cpu_die)(unsigned int cpu);
+#endif
 };
 
 extern void register_smp_ops(struct plat_smp_ops *ops);
diff --git a/arch/mips/include/asm/smp.h b/arch/mips/include/asm/smp.h
index 40e5ef1..aaa2d4a 100644
--- a/arch/mips/include/asm/smp.h
+++ b/arch/mips/include/asm/smp.h
@@ -13,6 +13,7 @@
 
 #include <linux/bitops.h>
 #include <linux/linkage.h>
+#include <linux/smp.h>
 #include <linux/threads.h>
 #include <linux/cpumask.h>
 
@@ -40,6 +41,7 @@ extern int __cpu_logical_map[NR_CPUS];
 /* Octeon - Tell another core to flush its icache */
 #define SMP_ICACHE_FLUSH	0x4
 
+extern volatile cpumask_t cpu_callin_map;
 
 extern void asmlinkage smp_bootstrap(void);
 
@@ -55,6 +57,24 @@ static inline void smp_send_reschedule(int cpu)
 	mp_ops->send_ipi_single(cpu, SMP_RESCHEDULE_YOURSELF);
 }
 
+#ifdef CONFIG_HOTPLUG_CPU
+static inline int __cpu_disable(void)
+{
+	extern struct plat_smp_ops *mp_ops;     /* private */
+
+	return mp_ops->cpu_disable();
+}
+
+static inline void __cpu_die(unsigned int cpu)
+{
+	extern struct plat_smp_ops *mp_ops;     /* private */
+
+	mp_ops->cpu_die(cpu);
+}
+
+extern void play_dead(void);
+#endif
+
 extern asmlinkage void smp_call_function_interrupt(void);
 
 extern void arch_send_call_function_single_ipi(int cpu);
diff --git a/arch/mips/include/asm/sn/addrs.h b/arch/mips/include/asm/sn/addrs.h
index 3a56d90..2367b56 100644
--- a/arch/mips/include/asm/sn/addrs.h
+++ b/arch/mips/include/asm/sn/addrs.h
@@ -11,6 +11,7 @@
 
 
 #ifndef __ASSEMBLY__
+#include <linux/smp.h>
 #include <linux/types.h>
 #endif /* !__ASSEMBLY__ */
 
diff --git a/arch/mips/jazz/irq.c b/arch/mips/jazz/irq.c
index d9b6a5b..7fd170d 100644
--- a/arch/mips/jazz/irq.c
+++ b/arch/mips/jazz/irq.c
@@ -10,6 +10,7 @@
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
+#include <linux/smp.h>
 #include <linux/spinlock.h>
 
 #include <asm/irq_cpu.h>
diff --git a/arch/mips/kernel/cevt-bcm1480.c b/arch/mips/kernel/cevt-bcm1480.c
index a5182a2..e02f79b 100644
--- a/arch/mips/kernel/cevt-bcm1480.c
+++ b/arch/mips/kernel/cevt-bcm1480.c
@@ -18,6 +18,7 @@
 #include <linux/clockchips.h>
 #include <linux/interrupt.h>
 #include <linux/percpu.h>
+#include <linux/smp.h>
 
 #include <asm/addrspace.h>
 #include <asm/io.h>
diff --git a/arch/mips/kernel/cevt-r4k.c b/arch/mips/kernel/cevt-r4k.c
index 0015e44..2652362 100644
--- a/arch/mips/kernel/cevt-r4k.c
+++ b/arch/mips/kernel/cevt-r4k.c
@@ -9,6 +9,7 @@
 #include <linux/clockchips.h>
 #include <linux/interrupt.h>
 #include <linux/percpu.h>
+#include <linux/smp.h>
 
 #include <asm/smtc_ipi.h>
 #include <asm/time.h>
diff --git a/arch/mips/kernel/cevt-sb1250.c b/arch/mips/kernel/cevt-sb1250.c
index 340f53e..ac5903d 100644
--- a/arch/mips/kernel/cevt-sb1250.c
+++ b/arch/mips/kernel/cevt-sb1250.c
@@ -18,6 +18,7 @@
 #include <linux/clockchips.h>
 #include <linux/interrupt.h>
 #include <linux/percpu.h>
+#include <linux/smp.h>
 
 #include <asm/addrspace.h>
 #include <asm/io.h>
diff --git a/arch/mips/kernel/cevt-smtc.c b/arch/mips/kernel/cevt-smtc.c
index df6f5bc..98bd7de 100644
--- a/arch/mips/kernel/cevt-smtc.c
+++ b/arch/mips/kernel/cevt-smtc.c
@@ -10,6 +10,7 @@
 #include <linux/clockchips.h>
 #include <linux/interrupt.h>
 #include <linux/percpu.h>
+#include <linux/smp.h>
 
 #include <asm/smtc_ipi.h>
 #include <asm/time.h>
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index b13b8eb..1abe990 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -14,6 +14,7 @@
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/ptrace.h>
+#include <linux/smp.h>
 #include <linux/stddef.h>
 
 #include <asm/bugs.h>
diff --git a/arch/mips/kernel/i8253.c b/arch/mips/kernel/i8253.c
index ed20e7f..f7d8d5d 100644
--- a/arch/mips/kernel/i8253.c
+++ b/arch/mips/kernel/i8253.c
@@ -7,6 +7,7 @@
 #include <linux/interrupt.h>
 #include <linux/jiffies.h>
 #include <linux/module.h>
+#include <linux/smp.h>
 #include <linux/spinlock.h>
 
 #include <asm/delay.h>
diff --git a/arch/mips/kernel/irq-gic.c b/arch/mips/kernel/irq-gic.c
index 3f43c2e..39000f1 100644
--- a/arch/mips/kernel/irq-gic.c
+++ b/arch/mips/kernel/irq-gic.c
@@ -2,6 +2,7 @@
 
 #include <linux/bitmap.h>
 #include <linux/init.h>
+#include <linux/smp.h>
 
 #include <asm/io.h>
 #include <asm/gic.h>
diff --git a/arch/mips/kernel/kgdb.c b/arch/mips/kernel/kgdb.c
index 6e152c8..50c9bb8 100644
--- a/arch/mips/kernel/kgdb.c
+++ b/arch/mips/kernel/kgdb.c
@@ -26,6 +26,7 @@
 #include <linux/kgdb.h>
 #include <linux/kdebug.h>
 #include <linux/sched.h>
+#include <linux/smp.h>
 #include <asm/inst.h>
 #include <asm/fpu.h>
 #include <asm/cacheflush.h>
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index 1eaaa45..c09d681 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -50,10 +50,15 @@
  */
 void __noreturn cpu_idle(void)
 {
+	int cpu;
+
+	/* CPU is going idle. */
+	cpu = smp_processor_id();
+
 	/* endless idle loop with no priority at all */
 	while (1) {
 		tick_nohz_stop_sched_tick(1);
-		while (!need_resched()) {
+		while (!need_resched() && cpu_online(cpu)) {
 #ifdef CONFIG_MIPS_MT_SMTC
 			extern void smtc_idle_loop_hook(void);
 
@@ -62,6 +67,12 @@ void __noreturn cpu_idle(void)
 			if (cpu_wait)
 				(*cpu_wait)();
 		}
+#ifdef CONFIG_HOTPLUG_CPU
+		if (!cpu_online(cpu) && !cpu_isset(cpu, cpu_callin_map) &&
+		    (system_state == SYSTEM_RUNNING ||
+		     system_state == SYSTEM_BOOTING))
+			play_dead();
+#endif
 		tick_nohz_restart_sched_tick();
 		preempt_enable_no_resched();
 		schedule();
diff --git a/arch/mips/kernel/smp-cmp.c b/arch/mips/kernel/smp-cmp.c
index f27beca..653be06 100644
--- a/arch/mips/kernel/smp-cmp.c
+++ b/arch/mips/kernel/smp-cmp.c
@@ -20,6 +20,7 @@
 
 #include <linux/kernel.h>
 #include <linux/sched.h>
+#include <linux/smp.h>
 #include <linux/cpumask.h>
 #include <linux/interrupt.h>
 #include <linux/compiler.h>
diff --git a/arch/mips/kernel/smp-up.c b/arch/mips/kernel/smp-up.c
index 878e373..2508d55 100644
--- a/arch/mips/kernel/smp-up.c
+++ b/arch/mips/kernel/smp-up.c
@@ -55,6 +55,18 @@ static void __init up_prepare_cpus(unsigned int max_cpus)
 {
 }
 
+#ifdef CONFIG_HOTPLUG_CPU
+static int up_cpu_disable(void)
+{
+	return -ENOSYS;
+}
+
+static void up_cpu_die(unsigned int cpu)
+{
+	BUG();
+}
+#endif
+
 struct plat_smp_ops up_smp_ops = {
 	.send_ipi_single	= up_send_ipi_single,
 	.send_ipi_mask		= up_send_ipi_mask,
@@ -64,4 +76,8 @@ struct plat_smp_ops up_smp_ops = {
 	.boot_secondary		= up_boot_secondary,
 	.smp_setup		= up_smp_setup,
 	.prepare_cpus		= up_prepare_cpus,
+#ifdef CONFIG_HOTPLUG_CPU
+	.cpu_disable		= up_cpu_disable,
+	.cpu_die		= up_cpu_die,
+#endif
 };
diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index c937506..bc7d9b0 100644
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -22,6 +22,7 @@
 #include <linux/delay.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
+#include <linux/smp.h>
 #include <linux/spinlock.h>
 #include <linux/threads.h>
 #include <linux/module.h>
@@ -44,7 +45,7 @@
 #include <asm/mipsmtregs.h>
 #endif /* CONFIG_MIPS_MT_SMTC */
 
-static volatile cpumask_t cpu_callin_map;	/* Bitmask of started secondaries */
+volatile cpumask_t cpu_callin_map;	/* Bitmask of started secondaries */
 int __cpu_number_map[NR_CPUS];		/* Map physical to logical */
 int __cpu_logical_map[NR_CPUS];		/* Map logical to physical */
 
@@ -200,6 +201,8 @@ void __devinit smp_prepare_boot_cpu(void)
  * and keep control until "cpu_online(cpu)" is set.  Note: cpu is
  * physical, not logical.
  */
+static struct task_struct *cpu_idle_thread[NR_CPUS];
+
 int __cpuinit __cpu_up(unsigned int cpu)
 {
 	struct task_struct *idle;
@@ -209,9 +212,16 @@ int __cpuinit __cpu_up(unsigned int cpu)
 	 * The following code is purely to make sure
 	 * Linux can schedule processes on this slave.
 	 */
-	idle = fork_idle(cpu);
-	if (IS_ERR(idle))
-		panic(KERN_ERR "Fork failed for CPU %d", cpu);
+	if (!cpu_idle_thread[cpu]) {
+		idle = fork_idle(cpu);
+		cpu_idle_thread[cpu] = idle;
+
+		if (IS_ERR(idle))
+			panic(KERN_ERR "Fork failed for CPU %d", cpu);
+	} else {
+		idle = cpu_idle_thread[cpu];
+		init_idle(idle, cpu);
+	}
 
 	mp_ops->boot_secondary(cpu, idle);
 
diff --git a/arch/mips/kernel/smtc.c b/arch/mips/kernel/smtc.c
index 37d51cd..8a0626c 100644
--- a/arch/mips/kernel/smtc.c
+++ b/arch/mips/kernel/smtc.c
@@ -20,6 +20,7 @@
 #include <linux/clockchips.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
+#include <linux/smp.h>
 #include <linux/cpumask.h>
 #include <linux/interrupt.h>
 #include <linux/kernel_stat.h>
diff --git a/arch/mips/kernel/topology.c b/arch/mips/kernel/topology.c
index 660e44e..cf3eb61 100644
--- a/arch/mips/kernel/topology.c
+++ b/arch/mips/kernel/topology.c
@@ -17,7 +17,10 @@ static int __init topology_init(void)
 #endif /* CONFIG_NUMA */
 
 	for_each_present_cpu(i) {
-		ret = register_cpu(&per_cpu(cpu_devices, i), i);
+		struct cpu *c = &per_cpu(cpu_devices, i);
+
+		c->hotpluggable = 1;
+		ret = register_cpu(c, i);
 		if (ret)
 			printk(KERN_WARNING "topology_init: register_cpu %d "
 			       "failed (%d)\n", i, ret);
diff --git a/arch/mips/mipssim/sim_time.c b/arch/mips/mipssim/sim_time.c
index 881ecbc..0cea932 100644
--- a/arch/mips/mipssim/sim_time.c
+++ b/arch/mips/mipssim/sim_time.c
@@ -91,6 +91,7 @@ unsigned __cpuinit get_c0_compare_int(void)
 		mips_cpu_timer_irq = MSC01E_INT_BASE + MSC01E_INT_CPUCTR;
 	} else {
 #endif
+	       {
 		if (cpu_has_vint)
 			set_vi_handler(cp0_compare_irq, mips_timer_dispatch);
 		mips_cpu_timer_irq = MIPS_CPU_IRQ_BASE + cp0_compare_irq;
diff --git a/arch/mips/mm/c-octeon.c b/arch/mips/mm/c-octeon.c
index 44d01a0..b165cdc 100644
--- a/arch/mips/mm/c-octeon.c
+++ b/arch/mips/mm/c-octeon.c
@@ -8,6 +8,7 @@
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
+#include <linux/smp.h>
 #include <linux/mm.h>
 #include <linux/bitops.h>
 #include <linux/cpu.h>
diff --git a/arch/mips/mm/c-r3k.c b/arch/mips/mm/c-r3k.c
index 5500c20..54e5f7b 100644
--- a/arch/mips/mm/c-r3k.c
+++ b/arch/mips/mm/c-r3k.c
@@ -12,6 +12,7 @@
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
+#include <linux/smp.h>
 #include <linux/mm.h>
 
 #include <asm/page.h>
diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c
index 71fe4cb..6721ee2 100644
--- a/arch/mips/mm/c-r4k.c
+++ b/arch/mips/mm/c-r4k.c
@@ -13,6 +13,7 @@
 #include <linux/kernel.h>
 #include <linux/linkage.h>
 #include <linux/sched.h>
+#include <linux/smp.h>
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/bitops.h>
diff --git a/arch/mips/mm/c-tx39.c b/arch/mips/mm/c-tx39.c
index f7c8f9c..6515b44 100644
--- a/arch/mips/mm/c-tx39.c
+++ b/arch/mips/mm/c-tx39.c
@@ -11,6 +11,7 @@
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
+#include <linux/smp.h>
 #include <linux/mm.h>
 
 #include <asm/cacheops.h>
diff --git a/arch/mips/mm/fault.c b/arch/mips/mm/fault.c
index 55767ad..6751ce9 100644
--- a/arch/mips/mm/fault.c
+++ b/arch/mips/mm/fault.c
@@ -102,7 +102,7 @@ good_area:
 	 * make sure we exit gracefully rather than endlessly redo
 	 * the fault.
 	 */
-	fault = handle_mm_fault(mm, vma, address, write);
+	fault = handle_mm_fault(mm, vma, address, write ? FAULT_FLAG_WRITE : 0);
 	if (unlikely(fault & VM_FAULT_ERROR)) {
 		if (fault & VM_FAULT_OOM)
 			goto out_of_memory;
diff --git a/arch/mips/mm/highmem.c b/arch/mips/mm/highmem.c
index 2b1309b..e274fda 100644
--- a/arch/mips/mm/highmem.c
+++ b/arch/mips/mm/highmem.c
@@ -1,5 +1,6 @@
 #include <linux/module.h>
 #include <linux/highmem.h>
+#include <linux/smp.h>
 #include <asm/fixmap.h>
 #include <asm/tlbflush.h>
 
diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index c551129..0e82050 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <linux/signal.h>
 #include <linux/sched.h>
+#include <linux/smp.h>
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/string.h>
diff --git a/arch/mips/mm/page.c b/arch/mips/mm/page.c
index 48060c6..f5c7375 100644
--- a/arch/mips/mm/page.c
+++ b/arch/mips/mm/page.c
@@ -10,6 +10,7 @@
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
+#include <linux/smp.h>
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/proc_fs.h>
diff --git a/arch/mips/mm/tlb-r3k.c b/arch/mips/mm/tlb-r3k.c
index 1c0048a..0f5ab23 100644
--- a/arch/mips/mm/tlb-r3k.c
+++ b/arch/mips/mm/tlb-r3k.c
@@ -13,6 +13,7 @@
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
+#include <linux/smp.h>
 #include <linux/mm.h>
 
 #include <asm/page.h>
diff --git a/arch/mips/mm/tlb-r4k.c b/arch/mips/mm/tlb-r4k.c
index f60fe51..cee502c 100644
--- a/arch/mips/mm/tlb-r4k.c
+++ b/arch/mips/mm/tlb-r4k.c
@@ -10,6 +10,7 @@
  */
 #include <linux/init.h>
 #include <linux/sched.h>
+#include <linux/smp.h>
 #include <linux/mm.h>
 #include <linux/hugetlb.h>
 
diff --git a/arch/mips/mm/tlb-r8k.c b/arch/mips/mm/tlb-r8k.c
index 4ec95cc..2b82f23 100644
--- a/arch/mips/mm/tlb-r8k.c
+++ b/arch/mips/mm/tlb-r8k.c
@@ -10,6 +10,7 @@
  */
 #include <linux/init.h>
 #include <linux/sched.h>
+#include <linux/smp.h>
 #include <linux/mm.h>
 
 #include <asm/cpu.h>
diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index 8f606ea..9a17bf8 100644
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -23,6 +23,7 @@
 #include <linux/bug.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
+#include <linux/smp.h>
 #include <linux/string.h>
 #include <linux/init.h>
 
diff --git a/arch/mips/mti-malta/malta-int.c b/arch/mips/mti-malta/malta-int.c
index ea17611..b4eaf13 100644
--- a/arch/mips/mti-malta/malta-int.c
+++ b/arch/mips/mti-malta/malta-int.c
@@ -24,6 +24,7 @@
 #include <linux/init.h>
 #include <linux/irq.h>
 #include <linux/sched.h>
+#include <linux/smp.h>
 #include <linux/slab.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
diff --git a/arch/mips/pci/pci-ip27.c b/arch/mips/pci/pci-ip27.c
index dda6f20..a0e726e 100644
--- a/arch/mips/pci/pci-ip27.c
+++ b/arch/mips/pci/pci-ip27.c
@@ -10,6 +10,7 @@
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/pci.h>
+#include <linux/smp.h>
 #include <asm/sn/arch.h>
 #include <asm/pci/bridge.h>
 #include <asm/paccess.h>
diff --git a/arch/mips/pmc-sierra/yosemite/smp.c b/arch/mips/pmc-sierra/yosemite/smp.c
index f78c29b..8ace277 100644
--- a/arch/mips/pmc-sierra/yosemite/smp.c
+++ b/arch/mips/pmc-sierra/yosemite/smp.c
@@ -1,5 +1,6 @@
 #include <linux/linkage.h>
 #include <linux/sched.h>
+#include <linux/smp.h>
 
 #include <asm/pmon.h>
 #include <asm/titan_dep.h>
diff --git a/arch/mips/power/hibernate.S b/arch/mips/power/hibernate.S
index 486bd3f..4b8174b 100644
--- a/arch/mips/power/hibernate.S
+++ b/arch/mips/power/hibernate.S
@@ -43,15 +43,6 @@ LEAF(swsusp_arch_resume)
 	bne t1, t3, 1b
 	PTR_L t0, PBE_NEXT(t0)
 	bnez t0, 0b
-	/* flush caches to make sure context is in memory */
-	PTR_L t0, __flush_cache_all
-	jalr t0
-	/* flush tlb entries */
-#ifdef CONFIG_SMP
-	jal	flush_tlb_all
-#else
-	jal	local_flush_tlb_all
-#endif
 	PTR_LA t0, saved_regs
 	PTR_L ra, PT_R31(t0)
 	PTR_L sp, PT_R29(t0)
diff --git a/arch/mips/sgi-ip27/ip27-init.c b/arch/mips/sgi-ip27/ip27-init.c
index 4a500e8..51d3a4f 100644
--- a/arch/mips/sgi-ip27/ip27-init.c
+++ b/arch/mips/sgi-ip27/ip27-init.c
@@ -9,6 +9,7 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/sched.h>
+#include <linux/smp.h>
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/cpumask.h>
diff --git a/arch/mips/sgi-ip27/ip27-irq.c b/arch/mips/sgi-ip27/ip27-irq.c
index 1bb692a..c1c8e40 100644
--- a/arch/mips/sgi-ip27/ip27-irq.c
+++ b/arch/mips/sgi-ip27/ip27-irq.c
@@ -18,6 +18,7 @@
 #include <linux/ioport.h>
 #include <linux/timex.h>
 #include <linux/slab.h>
+#include <linux/smp.h>
 #include <linux/random.h>
 #include <linux/kernel.h>
 #include <linux/kernel_stat.h>
diff --git a/arch/mips/sgi-ip27/ip27-timer.c b/arch/mips/sgi-ip27/ip27-timer.c
index f10a7cd..6d0e59f 100644
--- a/arch/mips/sgi-ip27/ip27-timer.c
+++ b/arch/mips/sgi-ip27/ip27-timer.c
@@ -10,6 +10,7 @@
 #include <linux/interrupt.h>
 #include <linux/kernel_stat.h>
 #include <linux/param.h>
+#include <linux/smp.h>
 #include <linux/time.h>
 #include <linux/timex.h>
 #include <linux/mm.h>
diff --git a/arch/mips/sgi-ip27/ip27-xtalk.c b/arch/mips/sgi-ip27/ip27-xtalk.c
index 6ae64e8..5e871e7 100644
--- a/arch/mips/sgi-ip27/ip27-xtalk.c
+++ b/arch/mips/sgi-ip27/ip27-xtalk.c
@@ -9,6 +9,7 @@
 
 #include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/smp.h>
 #include <asm/sn/types.h>
 #include <asm/sn/klconfig.h>
 #include <asm/sn/hub.h>
diff --git a/arch/mips/sibyte/bcm1480/irq.c b/arch/mips/sibyte/bcm1480/irq.c
index 690de06..ba59839 100644
--- a/arch/mips/sibyte/bcm1480/irq.c
+++ b/arch/mips/sibyte/bcm1480/irq.c
@@ -19,6 +19,7 @@
 #include <linux/init.h>
 #include <linux/linkage.h>
 #include <linux/interrupt.h>
+#include <linux/smp.h>
 #include <linux/spinlock.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
diff --git a/arch/mips/sibyte/common/cfe_console.c b/arch/mips/sibyte/common/cfe_console.c
index 81e3d54..1ad2da1 100644
--- a/arch/mips/sibyte/common/cfe_console.c
+++ b/arch/mips/sibyte/common/cfe_console.c
@@ -51,12 +51,13 @@ static int cfe_console_setup(struct console *cons, char *str)
 			setleds("u0cn");
 		} else if (!strcmp(consdev, "uart1")) {
 			setleds("u1cn");
+		} else
 #endif
 #ifdef CONFIG_VGA_CONSOLE
-		} else if (!strcmp(consdev, "pcconsole0")) {
-			setleds("pccn");
-#endif
+		       if (!strcmp(consdev, "pcconsole0")) {
+				setleds("pccn");
 		} else
+#endif
 			return -ENODEV;
 	}
 	return 0;
diff --git a/arch/mips/sni/time.c b/arch/mips/sni/time.c
index 69f5f88..0d9ec1a 100644
--- a/arch/mips/sni/time.c
+++ b/arch/mips/sni/time.c
@@ -1,5 +1,6 @@
 #include <linux/types.h>
 #include <linux/interrupt.h>
+#include <linux/smp.h>
 #include <linux/time.h>
 #include <linux/clockchips.h>