Merge branch 'x86-reboot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 reboot changes from Ingo Molnar:
 "The biggest change is a gentler method of rebooting/stopping via IRQs
  first and then via NMIs.  There are several cleanups in the tree as
  well."

* 'x86-reboot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/reboot: Update nonmi_ipi parameter
  x86/reboot: Use NMI to assist in shutting down if IRQ fails
  Revert "x86, reboot: Use NMI instead of REBOOT_VECTOR to stop cpus"
  x86/reboot: Clean up coding style
  x86/reboot: Reduce to a single DMI table for reboot quirks

2 files changed, 185 insertions, 192 deletions

diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index d840e69a853c..77215c23fba1 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -39,7 +39,8 @@ static int reboot_mode;
 enum reboot_type reboot_type = BOOT_ACPI;
 int reboot_force;
 
-/* This variable is used privately to keep track of whether or not
+/*
+ * This variable is used privately to keep track of whether or not
  * reboot_type is still set to its default value (i.e., reboot= hasn't
  * been set on the command line).  This is needed so that we can
  * suppress DMI scanning for reboot quirks.  Without it, it's
@@ -51,7 +52,8 @@ static int reboot_default = 1;
 static int reboot_cpu = -1;
 #endif
 
-/* This is set if we need to go through the 'emergency' path.
+/*
+ * This is set if we need to go through the 'emergency' path.
  * When machine_emergency_restart() is called, we may be on
  * an inconsistent state and won't be able to do a clean cleanup
  */
@@ -60,22 +62,24 @@ static int reboot_emergency;
 /* This is set by the PCI code if either type 1 or type 2 PCI is detected */
 bool port_cf9_safe = false;
 
-/* reboot=b[ios] | s[mp] | t[riple] | k[bd] | e[fi] [, [w]arm | [c]old] | p[ci]
-   warm   Don't set the cold reboot flag
-   cold   Set the cold reboot flag
-   bios   Reboot by jumping through the BIOS (only for X86_32)
-   smp    Reboot by executing reset on BSP or other CPU (only for X86_32)
-   triple Force a triple fault (init)
-   kbd    Use the keyboard controller. cold reset (default)
-   acpi   Use the RESET_REG in the FADT
-   efi    Use efi reset_system runtime service
-   pci    Use the so-called "PCI reset register", CF9
-   force  Avoid anything that could hang.
+/*
+ * reboot=b[ios] | s[mp] | t[riple] | k[bd] | e[fi] [, [w]arm | [c]old] | p[ci]
+ * warm   Don't set the cold reboot flag
+ * cold   Set the cold reboot flag
+ * bios   Reboot by jumping through the BIOS (only for X86_32)
+ * smp    Reboot by executing reset on BSP or other CPU (only for X86_32)
+ * triple Force a triple fault (init)
+ * kbd    Use the keyboard controller. cold reset (default)
+ * acpi   Use the RESET_REG in the FADT
+ * efi    Use efi reset_system runtime service
+ * pci    Use the so-called "PCI reset register", CF9
+ * force  Avoid anything that could hang.
  */
 static int __init reboot_setup(char *str)
 {
         for (;;) {
-                /* Having anything passed on the command line via
+                /*
+                 * Having anything passed on the command line via
                  * reboot= will cause us to disable DMI checking
                  * below.
                  */
@@ -98,9 +102,11 @@ static int __init reboot_setup(char *str)
                                 if (isdigit(*(str+2)))
                                         reboot_cpu = reboot_cpu*10 + (int)(*(str+2) - '0');
                         }
-                                /* we will leave sorting out the final value
-                                   when we are ready to reboot, since we might not
-                                   have detected BSP APIC ID or smp_num_cpu */
+                        /*
+                         * We will leave sorting out the final value
+                         * when we are ready to reboot, since we might not
+                         * have detected BSP APIC ID or smp_num_cpu
+                         */
                         break;
 #endif /* CONFIG_SMP */
 
@@ -150,6 +156,82 @@ static int __init set_bios_reboot(const struct dmi_system_id *d)
         return 0;
 }
 
+extern const unsigned char machine_real_restart_asm[];
+extern const u64 machine_real_restart_gdt[3];
+
+void machine_real_restart(unsigned int type)
+{
+        void *restart_va;
+        unsigned long restart_pa;
+        void (*restart_lowmem)(unsigned int);
+        u64 *lowmem_gdt;
+
+        local_irq_disable();
+
+        /*
+         * Write zero to CMOS register number 0x0f, which the BIOS POST
+         * routine will recognize as telling it to do a proper reboot.  (Well
+         * that's what this book in front of me says -- it may only apply to
+         * the Phoenix BIOS though, it's not clear).  At the same time,
+         * disable NMIs by setting the top bit in the CMOS address register,
+         * as we're about to do peculiar things to the CPU.  I'm not sure if
+         * `outb_p' is needed instead of just `outb'.  Use it to be on the
+         * safe side.  (Yes, CMOS_WRITE does outb_p's. -  Paul G.)
+         */
+        spin_lock(&rtc_lock);
+        CMOS_WRITE(0x00, 0x8f);
+        spin_unlock(&rtc_lock);
+
+        /*
+         * Switch back to the initial page table.
+         */
+        load_cr3(initial_page_table);
+
+        /*
+         * Write 0x1234 to absolute memory location 0x472.  The BIOS reads
+         * this on booting to tell it to "Bypass memory test (also warm
+         * boot)".  This seems like a fairly standard thing that gets set by
+         * REBOOT.COM programs, and the previous reset routine did this
+         * too. */
+        *((unsigned short *)0x472) = reboot_mode;
+
+        /* Patch the GDT in the low memory trampoline */
+        lowmem_gdt = TRAMPOLINE_SYM(machine_real_restart_gdt);
+
+        restart_va = TRAMPOLINE_SYM(machine_real_restart_asm);
+        restart_pa = virt_to_phys(restart_va);
+        restart_lowmem = (void (*)(unsigned int))restart_pa;
+
+        /* GDT[0]: GDT self-pointer */
+        lowmem_gdt[0] =
+                (u64)(sizeof(machine_real_restart_gdt) - 1) +
+                ((u64)virt_to_phys(lowmem_gdt) << 16);
+        /* GDT[1]: 64K real mode code segment */
+        lowmem_gdt[1] =
+                GDT_ENTRY(0x009b, restart_pa, 0xffff);
+
+        /* Jump to the identity-mapped low memory code */
+        restart_lowmem(type);
+}
+#ifdef CONFIG_APM_MODULE
+EXPORT_SYMBOL(machine_real_restart);
+#endif
+
+#endif /* CONFIG_X86_32 */
+
+/*
+ * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
+ */
+static int __init set_pci_reboot(const struct dmi_system_id *d)
+{
+        if (reboot_type != BOOT_CF9) {
+                reboot_type = BOOT_CF9;
+                printk(KERN_INFO "%s series board detected. "
+                       "Selecting PCI-method for reboots.\n", d->ident);
+        }
+        return 0;
+}
+
 static int __init set_kbd_reboot(const struct dmi_system_id *d)
 {
         if (reboot_type != BOOT_KBD) {
@@ -159,7 +241,12 @@ static int __init set_kbd_reboot(const struct dmi_system_id *d)
         return 0;
 }
 
+/*
+ * This is a single dmi_table handling all reboot quirks.  Note that
+ * REBOOT_BIOS is only available for 32bit
+ */
 static struct dmi_system_id __initdata reboot_dmi_table[] = {
+#ifdef CONFIG_X86_32
         {       /* Handle problems with rebooting on Dell E520's */
                 .callback = set_bios_reboot,
                 .ident = "Dell E520",
@@ -184,7 +271,7 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
                 },
         },
-        {       /* Handle problems with rebooting on Dell Optiplex 745's SFF*/
+        {       /* Handle problems with rebooting on Dell Optiplex 745's SFF */
                 .callback = set_bios_reboot,
                 .ident = "Dell OptiPlex 745",
                 .matches = {
@@ -192,7 +279,7 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
                 },
         },
-        {       /* Handle problems with rebooting on Dell Optiplex 745's DFF*/
+        {       /* Handle problems with rebooting on Dell Optiplex 745's DFF */
                 .callback = set_bios_reboot,
                 .ident = "Dell OptiPlex 745",
                 .matches = {
@@ -201,7 +288,7 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
                         DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
                 },
         },
-        {       /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
+        {       /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
                 .callback = set_bios_reboot,
                 .ident = "Dell OptiPlex 745",
                 .matches = {
@@ -210,7 +297,7 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
                         DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
                 },
         },
-        {   /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
+        {       /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
                 .callback = set_bios_reboot,
                 .ident = "Dell OptiPlex 330",
                 .matches = {
@@ -219,7 +306,7 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
                         DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
                 },
         },
-        {   /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
+        {       /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
                 .callback = set_bios_reboot,
                 .ident = "Dell OptiPlex 360",
                 .matches = {
@@ -228,7 +315,7 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
                         DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
                 },
         },
-        {       /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G*/
+        {       /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G */
                 .callback = set_bios_reboot,
                 .ident = "Dell OptiPlex 760",
                 .matches = {
@@ -301,7 +388,7 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
                         DMI_MATCH(DMI_PRODUCT_NAME, "SBC-FITPC2"),
                 },
         },
-        {       /* Handle problems with rebooting on ASUS P4S800 */
+        {       /* Handle problems with rebooting on ASUS P4S800 */
                 .callback = set_bios_reboot,
                 .ident = "ASUS P4S800",
                 .matches = {
@@ -309,7 +396,9 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
                         DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
                 },
         },
-        { /* Handle reboot issue on Acer Aspire one */
+#endif /* CONFIG_X86_32 */
+
+        {       /* Handle reboot issue on Acer Aspire one */
                 .callback = set_kbd_reboot,
                 .ident = "Acer Aspire One A110",
                 .matches = {
@@ -317,96 +406,6 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
                         DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"),
                 },
         },
-        { }
-};
-
-static int __init reboot_init(void)
-{
-        /* Only do the DMI check if reboot_type hasn't been overridden
-         * on the command line
-         */
-        if (reboot_default) {
-                dmi_check_system(reboot_dmi_table);
-        }
-        return 0;
-}
-core_initcall(reboot_init);
-
-extern const unsigned char machine_real_restart_asm[];
-extern const u64 machine_real_restart_gdt[3];
-
-void machine_real_restart(unsigned int type)
-{
-        void *restart_va;
-        unsigned long restart_pa;
-        void (*restart_lowmem)(unsigned int);
-        u64 *lowmem_gdt;
-
-        local_irq_disable();
-
-        /* Write zero to CMOS register number 0x0f, which the BIOS POST
-           routine will recognize as telling it to do a proper reboot.  (Well
-           that's what this book in front of me says -- it may only apply to
-           the Phoenix BIOS though, it's not clear).  At the same time,
-           disable NMIs by setting the top bit in the CMOS address register,
-           as we're about to do peculiar things to the CPU.  I'm not sure if
-           `outb_p' is needed instead of just `outb'.  Use it to be on the
-           safe side.  (Yes, CMOS_WRITE does outb_p's. -  Paul G.)
-         */
-        spin_lock(&rtc_lock);
-        CMOS_WRITE(0x00, 0x8f);
-        spin_unlock(&rtc_lock);
-
-        /*
-         * Switch back to the initial page table.
-         */
-        load_cr3(initial_page_table);
-
-        /* Write 0x1234 to absolute memory location 0x472.  The BIOS reads
-           this on booting to tell it to "Bypass memory test (also warm
-           boot)".  This seems like a fairly standard thing that gets set by
-           REBOOT.COM programs, and the previous reset routine did this
-           too. */
-        *((unsigned short *)0x472) = reboot_mode;
-
-        /* Patch the GDT in the low memory trampoline */
-        lowmem_gdt = TRAMPOLINE_SYM(machine_real_restart_gdt);
-
-        restart_va = TRAMPOLINE_SYM(machine_real_restart_asm);
-        restart_pa = virt_to_phys(restart_va);
-        restart_lowmem = (void (*)(unsigned int))restart_pa;
-
-        /* GDT[0]: GDT self-pointer */
-        lowmem_gdt[0] =
-                (u64)(sizeof(machine_real_restart_gdt) - 1) +
-                ((u64)virt_to_phys(lowmem_gdt) << 16);
-        /* GDT[1]: 64K real mode code segment */
-        lowmem_gdt[1] =
-                GDT_ENTRY(0x009b, restart_pa, 0xffff);
-
-        /* Jump to the identity-mapped low memory code */
-        restart_lowmem(type);
-}
-#ifdef CONFIG_APM_MODULE
-EXPORT_SYMBOL(machine_real_restart);
-#endif
-
-#endif /* CONFIG_X86_32 */
-
-/*
- * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
- */
-static int __init set_pci_reboot(const struct dmi_system_id *d)
-{
-        if (reboot_type != BOOT_CF9) {
-                reboot_type = BOOT_CF9;
-                printk(KERN_INFO "%s series board detected. "
-                       "Selecting PCI-method for reboots.\n", d->ident);
-        }
-        return 0;
-}
-
-static struct dmi_system_id __initdata pci_reboot_dmi_table[] = {
         {       /* Handle problems with rebooting on Apple MacBook5 */
                 .callback = set_pci_reboot,
                 .ident = "Apple MacBook5",
@@ -474,17 +473,17 @@ static struct dmi_system_id __initdata pci_reboot_dmi_table[] = {
         { }
 };
 
-static int __init pci_reboot_init(void)
+static int __init reboot_init(void)
 {
-        /* Only do the DMI check if reboot_type hasn't been overridden
+        /*
+         * Only do the DMI check if reboot_type hasn't been overridden
          * on the command line
          */
-        if (reboot_default) {
-                dmi_check_system(pci_reboot_dmi_table);
-        }
+        if (reboot_default)
+                dmi_check_system(reboot_dmi_table);
         return 0;
 }
-core_initcall(pci_reboot_init);
+core_initcall(reboot_init);
 
 static inline void kb_wait(void)
 {
@@ -502,14 +501,14 @@ static void vmxoff_nmi(int cpu, struct pt_regs *regs)
         cpu_emergency_vmxoff();
 }
 
-/* Use NMIs as IPIs to tell all CPUs to disable virtualization
- */
+/* Use NMIs as IPIs to tell all CPUs to disable virtualization */
 static void emergency_vmx_disable_all(void)
 {
         /* Just make sure we won't change CPUs while doing this */
         local_irq_disable();
 
-        /* We need to disable VMX on all CPUs before rebooting, otherwise
+        /*
+         * We need to disable VMX on all CPUs before rebooting, otherwise
          * we risk hanging up the machine, because the CPU ignore INIT
          * signals when VMX is enabled.
          *
@@ -528,8 +527,7 @@ static void emergency_vmx_disable_all(void)
          * is still enabling VMX.
          */
         if (cpu_has_vmx() && cpu_vmx_enabled()) {
-                /* Disable VMX on this CPU.
-                 */
+                /* Disable VMX on this CPU. */
                 cpu_vmxoff();
 
                 /* Halt and disable VMX on the other CPUs */
@@ -574,12 +572,12 @@ static void native_machine_emergency_restart(void)
                 /* Could also try the reset bit in the Hammer NB */
                 switch (reboot_type) {
                 case BOOT_KBD:
-                        mach_reboot_fixups(); /* for board specific fixups */
+                        mach_reboot_fixups(); /* For board specific fixups */
 
                         for (i = 0; i < 10; i++) {
                                 kb_wait();
                                 udelay(50);
-                                outb(0xfe, 0x64); /* pulse reset low */
+                                outb(0xfe, 0x64); /* Pulse reset low */
                                 udelay(50);
                         }
                         if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
@@ -621,7 +619,7 @@ static void native_machine_emergency_restart(void)
 
                 case BOOT_CF9:
                         port_cf9_safe = true;
-                        /* fall through */
+                        /* Fall through */
 
                 case BOOT_CF9_COND:
                         if (port_cf9_safe) {
@@ -659,7 +657,8 @@ void native_machine_shutdown(void)
         /* Make certain I only run on the appropriate processor */
         set_cpus_allowed_ptr(current, cpumask_of(reboot_cpu_id));
 
-        /* O.K Now that I'm on the appropriate processor,
+        /*
+         * O.K Now that I'm on the appropriate processor,
          * stop all of the others.
          */
         stop_other_cpus();
@@ -697,12 +696,11 @@ static void native_machine_restart(char *__unused)
 
 static void native_machine_halt(void)
 {
-        /* stop other cpus and apics */
+        /* Stop other cpus and apics */
         machine_shutdown();
 
         tboot_shutdown(TB_SHUTDOWN_HALT);
 
-        /* stop this cpu */
         stop_this_cpu(NULL);
 }
 
@@ -713,7 +711,7 @@ static void native_machine_power_off(void)
                         machine_shutdown();
                 pm_power_off();
         }
-        /* a fallback in case there is no PM info available */
+        /* A fallback in case there is no PM info available */
         tboot_shutdown(TB_SHUTDOWN_HALT);
 }
 
@@ -775,7 +773,8 @@ static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
 
         cpu = raw_smp_processor_id();
 
-        /* Don't do anything if this handler is invoked on crashing cpu.
+        /*
+         * Don't do anything if this handler is invoked on crashing cpu.
          * Otherwise, system will completely hang. Crashing cpu can get
          * an NMI if system was initially booted with nmi_watchdog parameter.
          */
@@ -799,7 +798,8 @@ static void smp_send_nmi_allbutself(void)
         apic->send_IPI_allbutself(NMI_VECTOR);
 }
 
-/* Halt all other CPUs, calling the specified function on each of them
+/*
+ * Halt all other CPUs, calling the specified function on each of them
  *
  * This function can be used to halt all other CPUs on crash
  * or emergency reboot time. The function passed as parameter
@@ -810,7 +810,7 @@ void nmi_shootdown_cpus(nmi_shootdown_cb callback)
         unsigned long msecs;
         local_irq_disable();
 
-        /* Make a note of crashing cpu. Will be used in NMI callback.*/
+        /* Make a note of crashing cpu. Will be used in NMI callback. */
         crashing_cpu = safe_smp_processor_id();
 
         shootdown_callback = callback;
@@ -819,8 +819,9 @@ void nmi_shootdown_cpus(nmi_shootdown_cb callback)
         /* Would it be better to replace the trap vector here? */
         if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
                                  NMI_FLAG_FIRST, "crash"))
-                return;         /* return what? */
-        /* Ensure the new callback function is set before sending
+                return;         /* Return what? */
+        /*
+         * Ensure the new callback function is set before sending
          * out the NMI
          */
         wmb();
diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
index 66c74f481cab..48d2b7ded422 100644
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -109,6 +109,9 @@
  *      about nothing of note with C stepping upwards.
  */
 
+static atomic_t stopping_cpu = ATOMIC_INIT(-1);
+static bool smp_no_nmi_ipi = false;
+
 /*
  * this function sends a 'reschedule' IPI to another CPU.
  * it goes straight through and wastes no time serializing
@@ -149,8 +152,6 @@ void native_send_call_func_ipi(const struct cpumask *mask)
         free_cpumask_var(allbutself);
 }
 
-static atomic_t stopping_cpu = ATOMIC_INIT(-1);
-
 static int smp_stop_nmi_callback(unsigned int val, struct pt_regs *regs)
 {
         /* We are registered on stopping cpu too, avoid spurious NMI */
@@ -162,7 +163,19 @@ static int smp_stop_nmi_callback(unsigned int val, struct pt_regs *regs)
         return NMI_HANDLED;
 }
 
-static void native_nmi_stop_other_cpus(int wait)
+/*
+ * this function calls the 'stop' function on all other CPUs in the system.
+ */
+
+asmlinkage void smp_reboot_interrupt(void)
+{
+        ack_APIC_irq();
+        irq_enter();
+        stop_this_cpu(NULL);
+        irq_exit();
+}
+
+static void native_stop_other_cpus(int wait)
 {
         unsigned long flags;
         unsigned long timeout;
@@ -174,20 +187,25 @@ static void native_nmi_stop_other_cpus(int wait)
          * Use an own vector here because smp_call_function
          * does lots of things not suitable in a panic situation.
          */
+
+        /*
+         * We start by using the REBOOT_VECTOR irq.
+         * The irq is treated as a sync point to allow critical
+         * regions of code on other cpus to release their spin locks
+         * and re-enable irqs.  Jumping straight to an NMI might
+         * accidentally cause deadlocks with further shutdown/panic
+         * code.  By syncing, we give the cpus up to one second to
+         * finish their work before we force them off with the NMI.
+         */
         if (num_online_cpus() > 1) {
                 /* did someone beat us here? */
                 if (atomic_cmpxchg(&stopping_cpu, -1, safe_smp_processor_id()) != -1)
                         return;
 
-                if (register_nmi_handler(NMI_LOCAL, smp_stop_nmi_callback,
-                                         NMI_FLAG_FIRST, "smp_stop"))
-                        /* Note: we ignore failures here */
-                        return;
-
-                /* sync above data before sending NMI */
+                /* sync above data before sending IRQ */
                 wmb();
 
-                apic->send_IPI_allbutself(NMI_VECTOR);
+                apic->send_IPI_allbutself(REBOOT_VECTOR);
 
                 /*
                  * Don't wait longer than a second if the caller
@@ -197,63 +215,37 @@ static void native_nmi_stop_other_cpus(int wait)
                 while (num_online_cpus() > 1 && (wait || timeout--))
                         udelay(1);
         }
+        
+        /* if the REBOOT_VECTOR didn't work, try with the NMI */
+        if ((num_online_cpus() > 1) && (!smp_no_nmi_ipi))  {
+                if (register_nmi_handler(NMI_LOCAL, smp_stop_nmi_callback,
+                                         NMI_FLAG_FIRST, "smp_stop"))
+                        /* Note: we ignore failures here */
+                        /* Hope the REBOOT_IRQ is good enough */
+                        goto finish;
 
-        local_irq_save(flags);
-        disable_local_APIC();
-        local_irq_restore(flags);
-}
-
-/*
- * this function calls the 'stop' function on all other CPUs in the system.
- */
-
-asmlinkage void smp_reboot_interrupt(void)
-{
-        ack_APIC_irq();
-        irq_enter();
-        stop_this_cpu(NULL);
-        irq_exit();
-}
-
-static void native_irq_stop_other_cpus(int wait)
-{
-        unsigned long flags;
-        unsigned long timeout;
+                /* sync above data before sending IRQ */
+                wmb();
 
-        if (reboot_force)
-                return;
+                pr_emerg("Shutting down cpus with NMI\n");
 
-        /*
-         * Use an own vector here because smp_call_function
-         * does lots of things not suitable in a panic situation.
-         * On most systems we could also use an NMI here,
-         * but there are a few systems around where NMI
-         * is problematic so stay with an non NMI for now
-         * (this implies we cannot stop CPUs spinning with irq off
-         * currently)
-         */
-        if (num_online_cpus() > 1) {
-                apic->send_IPI_allbutself(REBOOT_VECTOR);
+                apic->send_IPI_allbutself(NMI_VECTOR);
 
                 /*
-                 * Don't wait longer than a second if the caller
+                 * Don't wait longer than a 10 ms if the caller
                  * didn't ask us to wait.
                  */
-                timeout = USEC_PER_SEC;
+                timeout = USEC_PER_MSEC * 10;
                 while (num_online_cpus() > 1 && (wait || timeout--))
                         udelay(1);
         }
 
+finish:
         local_irq_save(flags);
         disable_local_APIC();
         local_irq_restore(flags);
 }
 
-static void native_smp_disable_nmi_ipi(void)
-{
-        smp_ops.stop_other_cpus = native_irq_stop_other_cpus;
-}
-
 /*
  * Reschedule call back.
  */
@@ -287,8 +279,8 @@ void smp_call_function_single_interrupt(struct pt_regs *regs)
 
 static int __init nonmi_ipi_setup(char *str)
 {
-        native_smp_disable_nmi_ipi();
-        return 1;
+        smp_no_nmi_ipi = true;
+        return 1;
 }
 
 __setup("nonmi_ipi", nonmi_ipi_setup);
@@ -298,7 +290,7 @@ struct smp_ops smp_ops = {
         .smp_prepare_cpus       = native_smp_prepare_cpus,
         .smp_cpus_done          = native_smp_cpus_done,
 
-        .stop_other_cpus        = native_nmi_stop_other_cpus,
+        .stop_other_cpus        = native_stop_other_cpus,
         .smp_send_reschedule    = native_smp_send_reschedule,
 
         .cpu_up                 = native_cpu_up,