50 files changed, 489 insertions, 23 deletions

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index b29f0280d712..8c4be1f301cf 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 8dfa009e0070..384f1842bfb1 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 000000000000..0f7f84accf9a
--- /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 5f4e49ba4713..da559249cc2f 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 24e0ad63980a..0b891a9c6253 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 08ea46863fe5..6cf29c26e873 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 9dc10df32078..b160a706795d 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 4f1eed107b08..09b08d05ff72 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 d7f3eb03ad12..d3bea88d8744 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 64ffc0290b84..fd545547b8aa 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 40e5ef1d4d26..aaa2d4ab26dc 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 3a56d90abfa6..2367b56dcdef 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 d9b6a5b5399d..7fd170d007e7 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 a5182a207696..e02f79b1eb51 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 0015e442572b..2652362ce047 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 340f53e5c6b1..ac5903d1b20e 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 df6f5bc60572..98bd7de75778 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 b13b8eb30596..1abe9905c9c1 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 ed20e7fe65e3..f7d8d5d0ddbf 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 3f43c2e3aa5a..39000f103f2c 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 6e152c80cd4a..50c9bb880667 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 1eaaa450e20c..c09d681b7181 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 f27beca4b26d..653be061b9ec 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 878e3733bbb2..2508d55d68fd 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 c937506a03aa..bc7d9b05e2f4 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 37d51cd124e9..8a0626cbb108 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 660e44ed44d7..cf3eb61fad12 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 881ecbc1fa23..0cea932f1241 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 44d01a0a8490..b165cdcb2818 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 5500c20c79ae..54e5f7b9f440 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 71fe4cb778cd..6721ee2b1e8b 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 f7c8f9ce39c1..6515b4418714 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/highmem.c b/arch/mips/mm/highmem.c
index 2b1309b2580a..e274fda329f4 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 c5511294a9ee..0e820508ff23 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 48060c635acd..f5c73754d664 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 1c0048a6f5cf..0f5ab236ab69 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 f60fe513eb60..cee502caf398 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 4ec95cc2df2f..2b82f23df1a1 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 8f606ead826e..9a17bf8395df 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 ea176113fea9..b4eaf137e4a7 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 dda6f2058665..a0e726eb039a 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 f78c29b68d77..8ace27716232 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 486bd3fd01a1..4b8174b382d7 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 4a500e8cd3cc..51d3a4f2d7e1 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 1bb692a3b319..c1c8e40d65d6 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 f10a7cd64f7e..6d0e59ffba2e 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 6ae64e8dfc40..5e871e75a8d9 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 690de06bde90..ba59839a021e 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 81e3d54376e9..1ad2da103fe9 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 69f5f88711cc..0d9ec1a5c24a 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>