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Diffstat (limited to 'arch/ia64/kernel/smpboot.c')
-rw-r--r--arch/ia64/kernel/smpboot.c81
1 files changed, 50 insertions, 31 deletions
diff --git a/arch/ia64/kernel/smpboot.c b/arch/ia64/kernel/smpboot.c
index 5318f0c..ca1536d 100644
--- a/arch/ia64/kernel/smpboot.c
+++ b/arch/ia64/kernel/smpboot.c
@@ -9,6 +9,7 @@
* 02/07/31 David Mosberger <davidm@hpl.hp.com> Switch over to hotplug-CPU boot-sequence.
* smp_boot_cpus()/smp_commence() is replaced by
* smp_prepare_cpus()/__cpu_up()/smp_cpus_done().
+ * 04/06/21 Ashok Raj <ashok.raj@intel.com> Added CPU Hotplug Support
*/
#include <linux/config.h>
@@ -58,6 +59,37 @@
#define Dprintk(x...)
#endif
+#ifdef CONFIG_HOTPLUG_CPU
+/*
+ * Store all idle threads, this can be reused instead of creating
+ * a new thread. Also avoids complicated thread destroy functionality
+ * for idle threads.
+ */
+struct task_struct *idle_thread_array[NR_CPUS];
+
+/*
+ * Global array allocated for NR_CPUS at boot time
+ */
+struct sal_to_os_boot sal_boot_rendez_state[NR_CPUS];
+
+/*
+ * start_ap in head.S uses this to store current booting cpu
+ * info.
+ */
+struct sal_to_os_boot *sal_state_for_booting_cpu = &sal_boot_rendez_state[0];
+
+#define set_brendez_area(x) (sal_state_for_booting_cpu = &sal_boot_rendez_state[(x)]);
+
+#define get_idle_for_cpu(x) (idle_thread_array[(x)])
+#define set_idle_for_cpu(x,p) (idle_thread_array[(x)] = (p))
+
+#else
+
+#define get_idle_for_cpu(x) (NULL)
+#define set_idle_for_cpu(x,p)
+#define set_brendez_area(x)
+#endif
+
/*
* ITC synchronization related stuff:
@@ -345,7 +377,6 @@ start_secondary (void *unused)
{
/* Early console may use I/O ports */
ia64_set_kr(IA64_KR_IO_BASE, __pa(ia64_iobase));
-
Dprintk("start_secondary: starting CPU 0x%x\n", hard_smp_processor_id());
efi_map_pal_code();
cpu_init();
@@ -384,6 +415,13 @@ do_boot_cpu (int sapicid, int cpu)
.done = COMPLETION_INITIALIZER(c_idle.done),
};
DECLARE_WORK(work, do_fork_idle, &c_idle);
+
+ c_idle.idle = get_idle_for_cpu(cpu);
+ if (c_idle.idle) {
+ init_idle(c_idle.idle, cpu);
+ goto do_rest;
+ }
+
/*
* We can't use kernel_thread since we must avoid to reschedule the child.
*/
@@ -396,10 +434,15 @@ do_boot_cpu (int sapicid, int cpu)
if (IS_ERR(c_idle.idle))
panic("failed fork for CPU %d", cpu);
+
+ set_idle_for_cpu(cpu, c_idle.idle);
+
+do_rest:
task_for_booting_cpu = c_idle.idle;
Dprintk("Sending wakeup vector %lu to AP 0x%x/0x%x.\n", ap_wakeup_vector, cpu, sapicid);
+ set_brendez_area(cpu);
platform_send_ipi(cpu, ap_wakeup_vector, IA64_IPI_DM_INT, 0);
/*
@@ -555,16 +598,6 @@ void __devinit smp_prepare_boot_cpu(void)
#ifdef CONFIG_HOTPLUG_CPU
extern void fixup_irqs(void);
/* must be called with cpucontrol mutex held */
-static int __devinit cpu_enable(unsigned int cpu)
-{
- per_cpu(cpu_state,cpu) = CPU_UP_PREPARE;
- wmb();
-
- while (!cpu_online(cpu))
- cpu_relax();
- return 0;
-}
-
int __cpu_disable(void)
{
int cpu = smp_processor_id();
@@ -577,7 +610,7 @@ int __cpu_disable(void)
fixup_irqs();
local_flush_tlb_all();
- printk ("Disabled cpu %u\n", smp_processor_id());
+ cpu_clear(cpu, cpu_callin_map);
return 0;
}
@@ -589,12 +622,7 @@ void __cpu_die(unsigned int cpu)
/* They ack this in play_dead by setting CPU_DEAD */
if (per_cpu(cpu_state, cpu) == CPU_DEAD)
{
- /*
- * TBD: Enable this when physical removal
- * or when we put the processor is put in
- * SAL_BOOT_RENDEZ mode
- * cpu_clear(cpu, cpu_callin_map);
- */
+ printk ("CPU %d is now offline\n", cpu);
return;
}
msleep(100);
@@ -602,11 +630,6 @@ void __cpu_die(unsigned int cpu)
printk(KERN_ERR "CPU %u didn't die...\n", cpu);
}
#else /* !CONFIG_HOTPLUG_CPU */
-static int __devinit cpu_enable(unsigned int cpu)
-{
- return 0;
-}
-
int __cpu_disable(void)
{
return -ENOSYS;
@@ -648,16 +671,12 @@ __cpu_up (unsigned int cpu)
return -EINVAL;
/*
- * Already booted.. just enable and get outa idle lool
+ * Already booted cpu? not valid anymore since we dont
+ * do idle loop tightspin anymore.
*/
if (cpu_isset(cpu, cpu_callin_map))
- {
- cpu_enable(cpu);
- local_irq_enable();
- while (!cpu_isset(cpu, cpu_online_map))
- mb();
- return 0;
- }
+ return -EINVAL;
+
/* Processor goes to start_secondary(), sets online flag */
ret = do_boot_cpu(sapicid, cpu);
if (ret < 0)
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