diff options
Diffstat (limited to 'arch/ia64/kernel/smpboot.c')
| -rw-r--r-- | arch/ia64/kernel/smpboot.c | 81 |
1 files changed, 50 insertions, 31 deletions
diff --git a/arch/ia64/kernel/smpboot.c b/arch/ia64/kernel/smpboot.c index 5318f0cbfc2..ca1536db339 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) |