--- /dev/null
+
+From: Zwane Mwaikambo <zwane@linuxpower.ca>
+
+Find attached the i386 cpu hotplug patch updated for Ingo's latest round of
+goodies. In order to avoid dumping cpu hotplug code into kernel/irq/* i
+dropped the cpu_online check in do_IRQ() by modifying fixup_irqs(). The
+difference being that on cpu offline, fixup_irqs() is called before we
+clear the cpu from cpu_online_map and a long delay in order to ensure that
+we never have any queued external interrupts on the APICs. Due to my usual
+test victims being in boxes a continent away this hasn't been tested, but
+i'll cover bug reports (nudge, Nathan! ;)
+
+1) Add CONFIG_HOTPLUG_CPU
+2) disable local APIC timer on dead cpus.
+3) Disable preempt around irq balancing to prevent CPUs going down.
+4) Print irq stats for all possible cpus.
+5) Debugging check for interrupts on offline cpus.
+6) Hacky fixup_irqs() to redirect irqs when cpus go off/online.
+7) play_dead() for offline cpus to spin inside.
+8) Handle offline cpus set in flush_tlb_others().
+9) Grab lock earlier in smp_call_function() to prevent CPUs going down.
+10) Implement __cpu_disable() and __cpu_die().
+11) Enable local interrupts in cpu_enable() after fixup_irqs()
+12) Don't fiddle with NMI on dead cpu, but leave intact on other cpus.
+13) Program IRQ affinity whilst cpu is still in cpu_online_map on offline.
+
+Signed-off-by: Zwane Mwaikambo <zwane@linuxpower.ca>
+DESC
+ppc64: fix hotplug cpu
+EDESC
+From: Zwane Mwaikambo <zwane@fsmlabs.com>
+
+I seem to have broken this when I moved the clearing of the dying cpu to
+arch specific code.
+
+Signed-off-by: Zwane Mwaikambo <zwane@fsmlabs.com>
+Signed-off-by: Andrew Morton <akpm@osdl.org>
+---
+
+ 25-akpm/arch/i386/Kconfig | 9 ++
+ 25-akpm/arch/i386/kernel/apic.c | 3
+ 25-akpm/arch/i386/kernel/io_apic.c | 2
+ 25-akpm/arch/i386/kernel/irq.c | 66 +++++++++++++++++----
+ 25-akpm/arch/i386/kernel/msr.c | 2
+ 25-akpm/arch/i386/kernel/process.c | 35 +++++++++++
+ 25-akpm/arch/i386/kernel/smp.c | 25 +++++---
+ 25-akpm/arch/i386/kernel/smpboot.c | 98 ++++++++++++++++++++++++++++++--
+ 25-akpm/arch/i386/kernel/traps.c | 8 ++
+ 25-akpm/arch/ia64/kernel/smpboot.c | 3
+ 25-akpm/arch/ppc64/kernel/pSeries_smp.c | 5 +
+ 25-akpm/arch/s390/kernel/smp.c | 4 -
+ 25-akpm/include/asm-i386/cpu.h | 2
+ 25-akpm/include/asm-i386/irq.h | 4 +
+ 25-akpm/include/asm-i386/smp.h | 3
+ 25-akpm/kernel/cpu.c | 14 +---
+ arch/ppc64/kernel/smp.c | 0
+ 17 files changed, 242 insertions(+), 41 deletions(-)
+
+diff -puN arch/i386/Kconfig~i386-cpu-hotplug-updated-for-mm arch/i386/Kconfig
+--- 25/arch/i386/Kconfig~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800
++++ 25-akpm/arch/i386/Kconfig 2005-02-23 02:20:06.000000000 -0800
+@@ -1205,6 +1205,15 @@ config SCx200
+ This support is also available as a module. If compiled as a
+ module, it will be called scx200.
+
++config HOTPLUG_CPU
++ bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
++ depends on SMP && HOTPLUG && EXPERIMENTAL
++ ---help---
++ Say Y here to experiment with turning CPUs off and on. CPUs
++ can be controlled through /sys/devices/system/cpu.
++
++ Say N.
++
+ source "drivers/pcmcia/Kconfig"
+
+ source "drivers/pci/hotplug/Kconfig"
+diff -puN arch/i386/kernel/apic.c~i386-cpu-hotplug-updated-for-mm arch/i386/kernel/apic.c
+--- 25/arch/i386/kernel/apic.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800
++++ 25-akpm/arch/i386/kernel/apic.c 2005-02-23 02:20:06.000000000 -0800
+@@ -26,6 +26,7 @@
+ #include <linux/mc146818rtc.h>
+ #include <linux/kernel_stat.h>
+ #include <linux/sysdev.h>
++#include <linux/cpu.h>
+
+ #include <asm/atomic.h>
+ #include <asm/smp.h>
+@@ -1048,7 +1049,7 @@ void __init setup_secondary_APIC_clock(v
+ setup_APIC_timer(calibration_result);
+ }
+
+-void __init disable_APIC_timer(void)
++void __devinit disable_APIC_timer(void)
+ {
+ if (using_apic_timer) {
+ unsigned long v;
+diff -puN arch/i386/kernel/io_apic.c~i386-cpu-hotplug-updated-for-mm arch/i386/kernel/io_apic.c
+--- 25/arch/i386/kernel/io_apic.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800
++++ 25-akpm/arch/i386/kernel/io_apic.c 2005-02-23 02:20:06.000000000 -0800
+@@ -576,9 +576,11 @@ static int balanced_irq(void *unused)
+ try_to_freeze(PF_FREEZE);
+ if (time_after(jiffies,
+ prev_balance_time+balanced_irq_interval)) {
++ preempt_disable();
+ do_irq_balance();
+ prev_balance_time = jiffies;
+ time_remaining = balanced_irq_interval;
++ preempt_enable();
+ }
+ }
+ return 0;
+diff -puN arch/i386/kernel/irq.c~i386-cpu-hotplug-updated-for-mm arch/i386/kernel/irq.c
+--- 25/arch/i386/kernel/irq.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800
++++ 25-akpm/arch/i386/kernel/irq.c 2005-02-23 02:20:06.000000000 -0800
+@@ -15,6 +15,9 @@
+ #include <linux/seq_file.h>
+ #include <linux/interrupt.h>
+ #include <linux/kernel_stat.h>
++#include <linux/notifier.h>
++#include <linux/cpu.h>
++#include <linux/delay.h>
+
+ #ifndef CONFIG_X86_LOCAL_APIC
+ /*
+@@ -209,9 +212,8 @@ int show_interrupts(struct seq_file *p,
+
+ if (i == 0) {
+ seq_printf(p, " ");
+- for (j=0; j<NR_CPUS; j++)
+- if (cpu_online(j))
+- seq_printf(p, "CPU%d ",j);
++ for_each_cpu(j)
++ seq_printf(p, "CPU%d ",j);
+ seq_putc(p, '\n');
+ }
+
+@@ -224,9 +226,8 @@ int show_interrupts(struct seq_file *p,
+ #ifndef CONFIG_SMP
+ seq_printf(p, "%10u ", kstat_irqs(i));
+ #else
+- for (j = 0; j < NR_CPUS; j++)
+- if (cpu_online(j))
+- seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
++ for_each_cpu(j)
++ seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
+ #endif
+ seq_printf(p, " %14s", irq_desc[i].handler->typename);
+ seq_printf(p, " %s", action->name);
+@@ -239,16 +240,13 @@ skip:
+ spin_unlock_irqrestore(&irq_desc[i].lock, flags);
+ } else if (i == NR_IRQS) {
+ seq_printf(p, "NMI: ");
+- for (j = 0; j < NR_CPUS; j++)
+- if (cpu_online(j))
+- seq_printf(p, "%10u ", nmi_count(j));
++ for_each_cpu(j)
++ seq_printf(p, "%10u ", nmi_count(j));
+ seq_putc(p, '\n');
+ #ifdef CONFIG_X86_LOCAL_APIC
+ seq_printf(p, "LOC: ");
+- for (j = 0; j < NR_CPUS; j++)
+- if (cpu_online(j))
+- seq_printf(p, "%10u ",
+- irq_stat[j].apic_timer_irqs);
++ for_each_cpu(j)
++ seq_printf(p, "%10u ", irq_stat[j].apic_timer_irqs);
+ seq_putc(p, '\n');
+ #endif
+ seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
+@@ -258,3 +256,45 @@ skip:
+ }
+ return 0;
+ }
++
++#ifdef CONFIG_HOTPLUG_CPU
++#include <mach_apic.h>
++
++void fixup_irqs(cpumask_t map)
++{
++ unsigned int irq;
++ static int warned;
++
++ for (irq = 0; irq < NR_IRQS; irq++) {
++ cpumask_t mask;
++ if (irq == 2)
++ continue;
++
++ cpus_and(mask, irq_affinity[irq], map);
++ if (any_online_cpu(mask) == NR_CPUS) {
++ printk("Breaking affinity for irq %i\n", irq);
++ mask = map;
++ }
++ if (irq_desc[irq].handler->set_affinity)
++ irq_desc[irq].handler->set_affinity(irq, mask);
++ else if (irq_desc[irq].action && !(warned++))
++ printk("Cannot set affinity for irq %i\n", irq);
++ }
++
++#if 0
++ barrier();
++ /* Ingo Molnar says: "after the IO-APIC masks have been redirected
++ [note the nop - the interrupt-enable boundary on x86 is two
++ instructions from sti] - to flush out pending hardirqs and
++ IPIs. After this point nothing is supposed to reach this CPU." */
++ __asm__ __volatile__("sti; nop; cli");
++ barrier();
++#else
++ /* That doesn't seem sufficient. Give it 1ms. */
++ local_irq_enable();
++ mdelay(1);
++ local_irq_disable();
++#endif
++}
++#endif
++
+diff -puN arch/i386/kernel/msr.c~i386-cpu-hotplug-updated-for-mm arch/i386/kernel/msr.c
+--- 25/arch/i386/kernel/msr.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800
++++ 25-akpm/arch/i386/kernel/msr.c 2005-02-23 02:20:06.000000000 -0800
+@@ -260,7 +260,7 @@ static struct file_operations msr_fops =
+ .open = msr_open,
+ };
+
+-static int msr_class_simple_device_add(int i)
++static int __devinit msr_class_simple_device_add(int i)
+ {
+ int err = 0;
+ struct class_device *class_err;
+diff -puN arch/i386/kernel/process.c~i386-cpu-hotplug-updated-for-mm arch/i386/kernel/process.c
+--- 25/arch/i386/kernel/process.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800
++++ 25-akpm/arch/i386/kernel/process.c 2005-02-23 02:20:06.000000000 -0800
+@@ -13,6 +13,7 @@
+
+ #include <stdarg.h>
+
++#include <linux/cpu.h>
+ #include <linux/errno.h>
+ #include <linux/sched.h>
+ #include <linux/fs.h>
+@@ -55,6 +56,9 @@
+ #include <linux/irq.h>
+ #include <linux/err.h>
+
++#include <asm/tlbflush.h>
++#include <asm/cpu.h>
++
+ asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
+
+ int hlt_counter;
+@@ -139,6 +143,34 @@ static void poll_idle (void)
+ }
+ }
+
++#ifdef CONFIG_HOTPLUG_CPU
++#include <asm/nmi.h>
++/* We don't actually take CPU down, just spin without interrupts. */
++static inline void play_dead(void)
++{
++ /* Ack it */
++ __get_cpu_var(cpu_state) = CPU_DEAD;
++
++ /* We shouldn't have to disable interrupts while dead, but
++ * some interrupts just don't seem to go away, and this makes
++ * it "work" for testing purposes. */
++ /* Death loop */
++ while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE)
++ cpu_relax();
++
++ local_irq_disable();
++ __flush_tlb_all();
++ cpu_set(smp_processor_id(), cpu_online_map);
++ enable_APIC_timer();
++ local_irq_enable();
++}
++#else
++static inline void play_dead(void)
++{
++ BUG();
++}
++#endif /* CONFIG_HOTPLUG_CPU */
++
+ /*
+ * The idle thread. There's no useful work to be
+ * done, so just try to conserve power and have a
+@@ -162,6 +194,9 @@ void cpu_idle (void)
+ if (!idle)
+ idle = default_idle;
+
++ if (cpu_is_offline(cpu))
++ play_dead();
++
+ irq_stat[cpu].idle_timestamp = jiffies;
+ idle();
+ }
+diff -puN arch/i386/kernel/smpboot.c~i386-cpu-hotplug-updated-for-mm arch/i386/kernel/smpboot.c
+--- 25/arch/i386/kernel/smpboot.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800
++++ 25-akpm/arch/i386/kernel/smpboot.c 2005-02-23 02:20:06.000000000 -0800
+@@ -44,6 +44,9 @@
+ #include <linux/smp_lock.h>
+ #include <linux/irq.h>
+ #include <linux/bootmem.h>
++#include <linux/notifier.h>
++#include <linux/cpu.h>
++#include <linux/percpu.h>
+
+ #include <linux/delay.h>
+ #include <linux/mc146818rtc.h>
+@@ -89,6 +92,9 @@ extern unsigned char trampoline_end [];
+ static unsigned char *trampoline_base;
+ static int trampoline_exec;
+
++/* State of each CPU. */
++DEFINE_PER_CPU(int, cpu_state) = { 0 };
++
+ /*
+ * Currently trivial. Write the real->protected mode
+ * bootstrap into the page concerned. The caller
+@@ -1095,6 +1101,9 @@ static void __init smp_boot_cpus(unsigne
+ who understands all this stuff should rewrite it properly. --RR 15/Jul/02 */
+ void __init smp_prepare_cpus(unsigned int max_cpus)
+ {
++ smp_commenced_mask = cpumask_of_cpu(0);
++ cpu_callin_map = cpumask_of_cpu(0);
++ mb();
+ smp_boot_cpus(max_cpus);
+ }
+
+@@ -1104,20 +1113,99 @@ void __devinit smp_prepare_boot_cpu(void
+ cpu_set(smp_processor_id(), cpu_callout_map);
+ }
+
+-int __devinit __cpu_up(unsigned int cpu)
++#ifdef CONFIG_HOTPLUG_CPU
++
++/* must be called with the cpucontrol mutex held */
++static int __devinit cpu_enable(unsigned int cpu)
+ {
+- /* This only works at boot for x86. See "rewrite" above. */
+- if (cpu_isset(cpu, smp_commenced_mask)) {
+- local_irq_enable();
+- return -ENOSYS;
++ /* get the target out of its holding state */
++ per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
++ wmb();
++
++ /* wait for the processor to ack it. timeout? */
++ while (!cpu_online(cpu))
++ cpu_relax();
++
++ fixup_irqs(cpu_online_map);
++ /* counter the disable in fixup_irqs() */
++ local_irq_enable();
++ return 0;
++}
++
++int __cpu_disable(void)
++{
++ cpumask_t map = cpu_online_map;
++ int cpu = smp_processor_id();
++
++ /*
++ * Perhaps use cpufreq to drop frequency, but that could go
++ * into generic code.
++ *
++ * We won't take down the boot processor on i386 due to some
++ * interrupts only being able to be serviced by the BSP.
++ * Especially so if we're not using an IOAPIC -zwane
++ */
++ if (cpu == 0)
++ return -EBUSY;
++
++ /* We enable the timer again on the exit path of the death loop */
++ disable_APIC_timer();
++ /* Allow any queued timer interrupts to get serviced */
++ local_irq_enable();
++ mdelay(1);
++ local_irq_disable();
++
++ cpu_clear(cpu, map);
++ fixup_irqs(map);
++ /* It's now safe to remove this processor from the online map */
++ cpu_clear(cpu, cpu_online_map);
++ return 0;
++}
++
++void __cpu_die(unsigned int cpu)
++{
++ /* We don't do anything here: idle task is faking death itself. */
++ unsigned int i;
++
++ for (i = 0; i < 10; i++) {
++ /* They ack this in play_dead by setting CPU_DEAD */
++ if (per_cpu(cpu_state, cpu) == CPU_DEAD)
++ return;
++ current->state = TASK_UNINTERRUPTIBLE;
++ schedule_timeout(HZ/10);
+ }
++ printk(KERN_ERR "CPU %u didn't die...\n", cpu);
++}
++#else /* ... !CONFIG_HOTPLUG_CPU */
++int __cpu_disable(void)
++{
++ return -ENOSYS;
++}
+
++void __cpu_die(unsigned int cpu)
++{
++ /* We said "no" in __cpu_disable */
++ BUG();
++}
++#endif /* CONFIG_HOTPLUG_CPU */
++
++int __devinit __cpu_up(unsigned int cpu)
++{
+ /* In case one didn't come up */
+ if (!cpu_isset(cpu, cpu_callin_map)) {
++ printk(KERN_DEBUG "skipping cpu%d, didn't come online\n", cpu);
+ local_irq_enable();
+ return -EIO;
+ }
+
++#ifdef CONFIG_HOTPLUG_CPU
++ /* Already up, and in cpu_quiescent now? */
++ if (cpu_isset(cpu, smp_commenced_mask)) {
++ cpu_enable(cpu);
++ return 0;
++ }
++#endif
++
+ local_irq_enable();
+ /* Unleash the CPU! */
+ cpu_set(cpu, smp_commenced_mask);
+diff -puN arch/i386/kernel/smp.c~i386-cpu-hotplug-updated-for-mm arch/i386/kernel/smp.c
+--- 25/arch/i386/kernel/smp.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800
++++ 25-akpm/arch/i386/kernel/smp.c 2005-02-23 02:20:06.000000000 -0800
+@@ -19,6 +19,7 @@
+ #include <linux/mc146818rtc.h>
+ #include <linux/cache.h>
+ #include <linux/interrupt.h>
++#include <linux/cpu.h>
+
+ #include <asm/mtrr.h>
+ #include <asm/tlbflush.h>
+@@ -163,7 +164,7 @@ void send_IPI_mask_bitmask(cpumask_t cpu
+ unsigned long flags;
+
+ local_irq_save(flags);
+-
++ WARN_ON(mask & ~cpus_addr(cpu_online_map)[0]);
+ /*
+ * Wait for idle.
+ */
+@@ -345,21 +346,21 @@ out:
+ static void flush_tlb_others(cpumask_t cpumask, struct mm_struct *mm,
+ unsigned long va)
+ {
+- cpumask_t tmp;
+ /*
+ * A couple of (to be removed) sanity checks:
+ *
+- * - we do not send IPIs to not-yet booted CPUs.
+ * - current CPU must not be in mask
+ * - mask must exist :)
+ */
+ BUG_ON(cpus_empty(cpumask));
+-
+- cpus_and(tmp, cpumask, cpu_online_map);
+- BUG_ON(!cpus_equal(cpumask, tmp));
+ BUG_ON(cpu_isset(smp_processor_id(), cpumask));
+ BUG_ON(!mm);
+
++ /* If a CPU which we ran on has gone down, OK. */
++ cpus_and(cpumask, cpumask, cpu_online_map);
++ if (cpus_empty(cpumask))
++ return;
++
+ /*
+ * i'm not happy about this global shared spinlock in the
+ * MM hot path, but we'll see how contended it is.
+@@ -484,6 +485,7 @@ void smp_send_nmi_allbutself(void)
+ */
+ void smp_send_reschedule(int cpu)
+ {
++ WARN_ON(cpu_is_offline(cpu));
+ send_IPI_mask(cpumask_of_cpu(cpu), RESCHEDULE_VECTOR);
+ }
+
+@@ -524,10 +526,16 @@ int smp_call_function (void (*func) (voi
+ */
+ {
+ struct call_data_struct data;
+- int cpus = num_online_cpus()-1;
++ int cpus;
+
+- if (!cpus)
++ /* Holding any lock stops cpus from going down. */
++ spin_lock(&call_lock);
++ cpus = num_online_cpus()-1;
++
++ if (!cpus) {
++ spin_unlock(&call_lock);
+ return 0;
++ }
+
+ /* Can deadlock when called with interrupts disabled */
+ WARN_ON(irqs_disabled());
+@@ -539,7 +547,6 @@ int smp_call_function (void (*func) (voi
+ if (wait)
+ atomic_set(&data.finished, 0);
+
+- spin_lock(&call_lock);
+ call_data = &data;
+ mb();
+
+diff -puN arch/i386/kernel/traps.c~i386-cpu-hotplug-updated-for-mm arch/i386/kernel/traps.c
+--- 25/arch/i386/kernel/traps.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800
++++ 25-akpm/arch/i386/kernel/traps.c 2005-02-23 02:20:06.000000000 -0800
+@@ -669,6 +669,14 @@ fastcall void do_nmi(struct pt_regs * re
+ nmi_enter();
+
+ cpu = smp_processor_id();
++
++#ifdef CONFIG_HOTPLUG_CPU
++ if (!cpu_online(cpu)) {
++ nmi_exit();
++ return;
++ }
++#endif
++
+ ++nmi_count(cpu);
+
+ if (!nmi_callback(regs, cpu))
+diff -puN arch/ia64/kernel/smpboot.c~i386-cpu-hotplug-updated-for-mm arch/ia64/kernel/smpboot.c
+--- 25/arch/ia64/kernel/smpboot.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800
++++ 25-akpm/arch/ia64/kernel/smpboot.c 2005-02-23 02:20:06.000000000 -0800
+@@ -590,9 +590,10 @@ int __cpu_disable(void)
+ if (cpu == 0)
+ return -EBUSY;
+
++ cpu_clear(cpu, cpu_online_map);
+ fixup_irqs();
+ local_flush_tlb_all();
+- printk ("Disabled cpu %u\n", smp_processor_id());
++ printk("Disabled cpu %u\n", cpu);
+ return 0;
+ }
+
+diff -puN arch/ppc64/kernel/smp.c~i386-cpu-hotplug-updated-for-mm arch/ppc64/kernel/smp.c
+diff -puN arch/s390/kernel/smp.c~i386-cpu-hotplug-updated-for-mm arch/s390/kernel/smp.c
+--- 25/arch/s390/kernel/smp.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800
++++ 25-akpm/arch/s390/kernel/smp.c 2005-02-23 02:20:06.000000000 -0800
+@@ -679,12 +679,14 @@ __cpu_disable(void)
+ {
+ unsigned long flags;
+ ec_creg_mask_parms cr_parms;
++ int cpu = smp_processor_id();
+
+ spin_lock_irqsave(&smp_reserve_lock, flags);
+- if (smp_cpu_reserved[smp_processor_id()] != 0) {
++ if (smp_cpu_reserved[cpu] != 0) {
+ spin_unlock_irqrestore(&smp_reserve_lock, flags);
+ return -EBUSY;
+ }
++ cpu_clear(cpu, cpu_online_map);
+
+ #ifdef CONFIG_PFAULT
+ /* Disable pfault pseudo page faults on this cpu. */
+diff -puN include/asm-i386/cpu.h~i386-cpu-hotplug-updated-for-mm include/asm-i386/cpu.h
+--- 25/include/asm-i386/cpu.h~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800
++++ 25-akpm/include/asm-i386/cpu.h 2005-02-23 02:20:06.000000000 -0800
+@@ -5,6 +5,7 @@
+ #include <linux/cpu.h>
+ #include <linux/topology.h>
+ #include <linux/nodemask.h>
++#include <linux/percpu.h>
+
+ #include <asm/node.h>
+
+@@ -17,4 +18,5 @@ extern int arch_register_cpu(int num);
+ extern void arch_unregister_cpu(int);
+ #endif
+
++DECLARE_PER_CPU(int, cpu_state);
+ #endif /* _ASM_I386_CPU_H_ */
+diff -puN include/asm-i386/irq.h~i386-cpu-hotplug-updated-for-mm include/asm-i386/irq.h
+--- 25/include/asm-i386/irq.h~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800
++++ 25-akpm/include/asm-i386/irq.h 2005-02-23 02:20:06.000000000 -0800
+@@ -38,4 +38,8 @@ extern void release_vm86_irqs(struct tas
+ extern int irqbalance_disable(char *str);
+ #endif
+
++#ifdef CONFIG_HOTPLUG_CPU
++extern void fixup_irqs(cpumask_t map);
++#endif
++
+ #endif /* _ASM_IRQ_H */
+diff -puN include/asm-i386/smp.h~i386-cpu-hotplug-updated-for-mm include/asm-i386/smp.h
+--- 25/include/asm-i386/smp.h~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800
++++ 25-akpm/include/asm-i386/smp.h 2005-02-23 02:20:06.000000000 -0800
+@@ -85,6 +85,9 @@ static __inline int logical_smp_processo
+ }
+
+ #endif
++
++extern int __cpu_disable(void);
++extern void __cpu_die(unsigned int cpu);
+ #endif /* !__ASSEMBLY__ */
+
+ #define NO_PROC_ID 0xFF /* No processor magic marker */
+diff -puN kernel/cpu.c~i386-cpu-hotplug-updated-for-mm kernel/cpu.c
+--- 25/kernel/cpu.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800
++++ 25-akpm/kernel/cpu.c 2005-02-23 02:20:06.000000000 -0800
+@@ -63,19 +63,15 @@ static int take_cpu_down(void *unused)
+ {
+ int err;
+
+- /* Take offline: makes arch_cpu_down somewhat easier. */
+- cpu_clear(smp_processor_id(), cpu_online_map);
+-
+ /* Ensure this CPU doesn't handle any more interrupts. */
+ err = __cpu_disable();
+ if (err < 0)
+- cpu_set(smp_processor_id(), cpu_online_map);
+- else
+- /* Force idle task to run as soon as we yield: it should
+- immediately notice cpu is offline and die quickly. */
+- sched_idle_next();
++ return err;
+
+- return err;
++ /* Force idle task to run as soon as we yield: it should
++ immediately notice cpu is offline and die quickly. */
++ sched_idle_next();
++ return 0;
+ }
+
+ int cpu_down(unsigned int cpu)
+diff -puN arch/ppc64/kernel/pSeries_smp.c~i386-cpu-hotplug-updated-for-mm arch/ppc64/kernel/pSeries_smp.c
+--- 25/arch/ppc64/kernel/pSeries_smp.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:08.000000000 -0800
++++ 25-akpm/arch/ppc64/kernel/pSeries_smp.c 2005-02-23 02:20:08.000000000 -0800
+@@ -86,10 +86,13 @@ static int query_cpu_stopped(unsigned in
+
+ int pSeries_cpu_disable(void)
+ {
++ int cpu = smp_processor_id();
++
++ cpu_clear(cpu, cpu_online_map);
+ systemcfg->processorCount--;
+
+ /*fix boot_cpuid here*/
+- if (smp_processor_id() == boot_cpuid)
++ if (cpu == boot_cpuid)
+ boot_cpuid = any_online_cpu(cpu_online_map);
+
+ /* FIXME: abstract this to not be platform specific later on */
+_
projects / xen.git / commitdiff