[PATCH] kexec: x86: factor out apic shutdown code

Factor out the apic and smp shutdown code from machine_restart so it can be
called by in the kexec reboot path as well.

By switching to the bootstrap cpu by default on reboot I can delete/simplify
some motherboard fixups well.

Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 26 insertions, 56 deletions

diff --git a/arch/i386/kernel/reboot.c b/arch/i386/kernel/reboot.c
index db912209a8d3..b3e584849961 100644
--- a/arch/i386/kernel/reboot.c
+++ b/arch/i386/kernel/reboot.c
@@ -26,7 +26,6 @@ static int reboot_mode;
 static int reboot_thru_bios;
 
 #ifdef CONFIG_SMP
-int reboot_smp = 0;
 static int reboot_cpu = -1;
 /* shamelessly grabbed from lib/vsprintf.c for readability */
 #define is_digit(c)     ((c) >= '0' && (c) <= '9')
@@ -49,7 +48,6 @@ static int __init reboot_setup(char *str)
                         break;
 #ifdef CONFIG_SMP
                 case 's': /* "smp" reboot by executing reset on BSP or other CPU*/
-                        reboot_smp = 1;
                         if (is_digit(*(str+1))) {
                                 reboot_cpu = (int) (*(str+1) - '0');
                                 if (is_digit(*(str+2))) 
@@ -88,33 +86,9 @@ static int __init set_bios_reboot(struct dmi_system_id *d)
         return 0;
 }
 
-/*
- * Some machines require the "reboot=s"  commandline option, this quirk makes that automatic.
- */
-static int __init set_smp_reboot(struct dmi_system_id *d)
-{
-#ifdef CONFIG_SMP
-        if (!reboot_smp) {
-                reboot_smp = 1;
-                printk(KERN_INFO "%s series board detected. Selecting SMP-method for reboots.\n", d->ident);
-        }
-#endif
-        return 0;
-}
-
-/*
- * Some machines require the "reboot=b,s"  commandline option, this quirk makes that automatic.
- */
-static int __init set_smp_bios_reboot(struct dmi_system_id *d)
-{
-        set_smp_reboot(d);
-        set_bios_reboot(d);
-        return 0;
-}
-
 static struct dmi_system_id __initdata reboot_dmi_table[] = {
         {       /* Handle problems with rebooting on Dell 1300's */
-                .callback = set_smp_bios_reboot,
+                .callback = set_bios_reboot,
                 .ident = "Dell PowerEdge 1300",
                 .matches = {
                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
@@ -301,41 +275,32 @@ void machine_real_restart(unsigned char *code, int length)
 EXPORT_SYMBOL(machine_real_restart);
 #endif
 
-void machine_restart(char * __unused)
+void machine_shutdown(void)
 {
 #ifdef CONFIG_SMP
-        int cpuid;
-        
-        cpuid = GET_APIC_ID(apic_read(APIC_ID));
-
-        if (reboot_smp) {
-
-                /* check to see if reboot_cpu is valid 
-                   if its not, default to the BSP */
-                if ((reboot_cpu == -1) ||  
-                      (reboot_cpu > (NR_CPUS -1))  || 
-                      !physid_isset(cpuid, phys_cpu_present_map))
-                        reboot_cpu = boot_cpu_physical_apicid;
-
-                reboot_smp = 0;  /* use this as a flag to only go through this once*/
-                /* re-run this function on the other CPUs
-                   it will fall though this section since we have 
-                   cleared reboot_smp, and do the reboot if it is the
-                   correct CPU, otherwise it halts. */
-                if (reboot_cpu != cpuid)
-                        smp_call_function((void *)machine_restart , NULL, 1, 0);
+        int reboot_cpu_id;
+
+        /* The boot cpu is always logical cpu 0 */
+        reboot_cpu_id = 0;
+
+        /* See if there has been given a command line override */
+        if ((reboot_cpu_id != -1) && (reboot_cpu < NR_CPUS) &&
+                cpu_isset(reboot_cpu, cpu_online_map)) {
+                reboot_cpu_id = reboot_cpu;
         }
 
-        /* if reboot_cpu is still -1, then we want a tradional reboot, 
-           and if we are not running on the reboot_cpu,, halt */
-        if ((reboot_cpu != -1) && (cpuid != reboot_cpu)) {
-                for (;;)
-                __asm__ __volatile__ ("hlt");
+        /* Make certain the cpu I'm rebooting on is online */
+        if (!cpu_isset(reboot_cpu_id, cpu_online_map)) {
+                reboot_cpu_id = smp_processor_id();
         }
-        /*
-         * Stop all CPUs and turn off local APICs and the IO-APIC, so
-         * other OSs see a clean IRQ state.
+
+        /* Make certain I only run on the appropriate processor */
+        set_cpus_allowed(current, cpumask_of_cpu(reboot_cpu_id));
+
+        /* O.K. Now that I'm on the appropriate processor, stop
+         * all of the others, and disable their local APICs.
          */
+
         smp_send_stop();
 #endif /* CONFIG_SMP */
 
@@ -344,6 +309,11 @@ void machine_restart(char * __unused)
 #ifdef CONFIG_X86_IO_APIC
         disable_IO_APIC();
 #endif
+}
+
+void machine_restart(char * __unused)
+{
+        machine_shutdown();
 
         if (!reboot_thru_bios) {
                 if (efi_enabled) {