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Diffstat (limited to 'arch/i386/kernel/smpboot.c')
-rw-r--r--arch/i386/kernel/smpboot.c349
1 files changed, 282 insertions, 67 deletions
diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c
index c20d96d5c15..d66bf489a2e 100644
--- a/arch/i386/kernel/smpboot.c
+++ b/arch/i386/kernel/smpboot.c
@@ -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>
@@ -56,18 +59,28 @@
#include <smpboot_hooks.h>
/* Set if we find a B stepping CPU */
-static int __initdata smp_b_stepping;
+static int __devinitdata smp_b_stepping;
/* Number of siblings per CPU package */
int smp_num_siblings = 1;
#ifdef CONFIG_X86_HT
EXPORT_SYMBOL(smp_num_siblings);
#endif
-int phys_proc_id[NR_CPUS]; /* Package ID of each logical CPU */
+
+/* Package ID of each logical CPU */
+int phys_proc_id[NR_CPUS] = {[0 ... NR_CPUS-1] = BAD_APICID};
EXPORT_SYMBOL(phys_proc_id);
-int cpu_core_id[NR_CPUS]; /* Core ID of each logical CPU */
+
+/* Core ID of each logical CPU */
+int cpu_core_id[NR_CPUS] = {[0 ... NR_CPUS-1] = BAD_APICID};
EXPORT_SYMBOL(cpu_core_id);
+cpumask_t cpu_sibling_map[NR_CPUS];
+EXPORT_SYMBOL(cpu_sibling_map);
+
+cpumask_t cpu_core_map[NR_CPUS];
+EXPORT_SYMBOL(cpu_core_map);
+
/* bitmap of online cpus */
cpumask_t cpu_online_map;
EXPORT_SYMBOL(cpu_online_map);
@@ -77,6 +90,12 @@ cpumask_t cpu_callout_map;
EXPORT_SYMBOL(cpu_callout_map);
static cpumask_t smp_commenced_mask;
+/* TSC's upper 32 bits can't be written in eariler CPU (before prescott), there
+ * is no way to resync one AP against BP. TBD: for prescott and above, we
+ * should use IA64's algorithm
+ */
+static int __devinitdata tsc_sync_disabled;
+
/* Per CPU bogomips and other parameters */
struct cpuinfo_x86 cpu_data[NR_CPUS] __cacheline_aligned;
EXPORT_SYMBOL(cpu_data);
@@ -96,13 +115,16 @@ static int trampoline_exec;
static void map_cpu_to_logical_apicid(void);
+/* 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
* has made sure it's suitably aligned.
*/
-static unsigned long __init setup_trampoline(void)
+static unsigned long __devinit setup_trampoline(void)
{
memcpy(trampoline_base, trampoline_data, trampoline_end - trampoline_data);
return virt_to_phys(trampoline_base);
@@ -132,7 +154,7 @@ void __init smp_alloc_memory(void)
* a given CPU
*/
-static void __init smp_store_cpu_info(int id)
+static void __devinit smp_store_cpu_info(int id)
{
struct cpuinfo_x86 *c = cpu_data + id;
@@ -326,7 +348,7 @@ extern void calibrate_delay(void);
static atomic_t init_deasserted;
-static void __init smp_callin(void)
+static void __devinit smp_callin(void)
{
int cpuid, phys_id;
unsigned long timeout;
@@ -411,16 +433,48 @@ static void __init smp_callin(void)
/*
* Synchronize the TSC with the BP
*/
- if (cpu_has_tsc && cpu_khz)
+ if (cpu_has_tsc && cpu_khz && !tsc_sync_disabled)
synchronize_tsc_ap();
}
static int cpucount;
+static inline void
+set_cpu_sibling_map(int cpu)
+{
+ int i;
+
+ if (smp_num_siblings > 1) {
+ for (i = 0; i < NR_CPUS; i++) {
+ if (!cpu_isset(i, cpu_callout_map))
+ continue;
+ if (cpu_core_id[cpu] == cpu_core_id[i]) {
+ cpu_set(i, cpu_sibling_map[cpu]);
+ cpu_set(cpu, cpu_sibling_map[i]);
+ }
+ }
+ } else {
+ cpu_set(cpu, cpu_sibling_map[cpu]);
+ }
+
+ if (current_cpu_data.x86_num_cores > 1) {
+ for (i = 0; i < NR_CPUS; i++) {
+ if (!cpu_isset(i, cpu_callout_map))
+ continue;
+ if (phys_proc_id[cpu] == phys_proc_id[i]) {
+ cpu_set(i, cpu_core_map[cpu]);
+ cpu_set(cpu, cpu_core_map[i]);
+ }
+ }
+ } else {
+ cpu_core_map[cpu] = cpu_sibling_map[cpu];
+ }
+}
+
/*
* Activate a secondary processor.
*/
-static void __init start_secondary(void *unused)
+static void __devinit start_secondary(void *unused)
{
/*
* Dont put anything before smp_callin(), SMP
@@ -443,7 +497,23 @@ static void __init start_secondary(void *unused)
* the local TLBs too.
*/
local_flush_tlb();
+
+ /* This must be done before setting cpu_online_map */
+ set_cpu_sibling_map(raw_smp_processor_id());
+ wmb();
+
+ /*
+ * We need to hold call_lock, so there is no inconsistency
+ * between the time smp_call_function() determines number of
+ * IPI receipients, and the time when the determination is made
+ * for which cpus receive the IPI. Holding this
+ * lock helps us to not include this cpu in a currently in progress
+ * smp_call_function().
+ */
+ lock_ipi_call_lock();
cpu_set(smp_processor_id(), cpu_online_map);
+ unlock_ipi_call_lock();
+ per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
/* We can take interrupts now: we're officially "up". */
local_irq_enable();
@@ -458,7 +528,7 @@ static void __init start_secondary(void *unused)
* from the task structure
* This function must not return.
*/
-void __init initialize_secondary(void)
+void __devinit initialize_secondary(void)
{
/*
* We don't actually need to load the full TSS,
@@ -572,7 +642,7 @@ static inline void __inquire_remote_apic(int apicid)
* INIT, INIT, STARTUP sequence will reset the chip hard for us, and this
* won't ... remember to clear down the APIC, etc later.
*/
-static int __init
+static int __devinit
wakeup_secondary_cpu(int logical_apicid, unsigned long start_eip)
{
unsigned long send_status = 0, accept_status = 0;
@@ -618,7 +688,7 @@ wakeup_secondary_cpu(int logical_apicid, unsigned long start_eip)
#endif /* WAKE_SECONDARY_VIA_NMI */
#ifdef WAKE_SECONDARY_VIA_INIT
-static int __init
+static int __devinit
wakeup_secondary_cpu(int phys_apicid, unsigned long start_eip)
{
unsigned long send_status = 0, accept_status = 0;
@@ -753,8 +823,43 @@ wakeup_secondary_cpu(int phys_apicid, unsigned long start_eip)
#endif /* WAKE_SECONDARY_VIA_INIT */
extern cpumask_t cpu_initialized;
+static inline int alloc_cpu_id(void)
+{
+ cpumask_t tmp_map;
+ int cpu;
+ cpus_complement(tmp_map, cpu_present_map);
+ cpu = first_cpu(tmp_map);
+ if (cpu >= NR_CPUS)
+ return -ENODEV;
+ return cpu;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static struct task_struct * __devinitdata cpu_idle_tasks[NR_CPUS];
+static inline struct task_struct * alloc_idle_task(int cpu)
+{
+ struct task_struct *idle;
+
+ if ((idle = cpu_idle_tasks[cpu]) != NULL) {
+ /* initialize thread_struct. we really want to avoid destroy
+ * idle tread
+ */
+ idle->thread.esp = (unsigned long)(((struct pt_regs *)
+ (THREAD_SIZE + (unsigned long) idle->thread_info)) - 1);
+ init_idle(idle, cpu);
+ return idle;
+ }
+ idle = fork_idle(cpu);
+
+ if (!IS_ERR(idle))
+ cpu_idle_tasks[cpu] = idle;
+ return idle;
+}
+#else
+#define alloc_idle_task(cpu) fork_idle(cpu)
+#endif
-static int __init do_boot_cpu(int apicid)
+static int __devinit do_boot_cpu(int apicid, int cpu)
/*
* NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
* (ie clustered apic addressing mode), this is a LOGICAL apic ID.
@@ -763,16 +868,17 @@ static int __init do_boot_cpu(int apicid)
{
struct task_struct *idle;
unsigned long boot_error;
- int timeout, cpu;
+ int timeout;
unsigned long start_eip;
unsigned short nmi_high = 0, nmi_low = 0;
- cpu = ++cpucount;
+ ++cpucount;
+
/*
* We can't use kernel_thread since we must avoid to
* reschedule the child.
*/
- idle = fork_idle(cpu);
+ idle = alloc_idle_task(cpu);
if (IS_ERR(idle))
panic("failed fork for CPU %d", cpu);
idle->thread.eip = (unsigned long) start_secondary;
@@ -839,13 +945,16 @@ static int __init do_boot_cpu(int apicid)
inquire_remote_apic(apicid);
}
}
- x86_cpu_to_apicid[cpu] = apicid;
+
if (boot_error) {
/* Try to put things back the way they were before ... */
unmap_cpu_to_logical_apicid(cpu);
cpu_clear(cpu, cpu_callout_map); /* was set here (do_boot_cpu()) */
cpu_clear(cpu, cpu_initialized); /* was set by cpu_init() */
cpucount--;
+ } else {
+ x86_cpu_to_apicid[cpu] = apicid;
+ cpu_set(cpu, cpu_present_map);
}
/* mark "stuck" area as not stuck */
@@ -854,6 +963,75 @@ static int __init do_boot_cpu(int apicid)
return boot_error;
}
+#ifdef CONFIG_HOTPLUG_CPU
+void cpu_exit_clear(void)
+{
+ int cpu = raw_smp_processor_id();
+
+ idle_task_exit();
+
+ cpucount --;
+ cpu_uninit();
+ irq_ctx_exit(cpu);
+
+ cpu_clear(cpu, cpu_callout_map);
+ cpu_clear(cpu, cpu_callin_map);
+ cpu_clear(cpu, cpu_present_map);
+
+ cpu_clear(cpu, smp_commenced_mask);
+ unmap_cpu_to_logical_apicid(cpu);
+}
+
+struct warm_boot_cpu_info {
+ struct completion *complete;
+ int apicid;
+ int cpu;
+};
+
+static void __devinit do_warm_boot_cpu(void *p)
+{
+ struct warm_boot_cpu_info *info = p;
+ do_boot_cpu(info->apicid, info->cpu);
+ complete(info->complete);
+}
+
+int __devinit smp_prepare_cpu(int cpu)
+{
+ DECLARE_COMPLETION(done);
+ struct warm_boot_cpu_info info;
+ struct work_struct task;
+ int apicid, ret;
+
+ lock_cpu_hotplug();
+ apicid = x86_cpu_to_apicid[cpu];
+ if (apicid == BAD_APICID) {
+ ret = -ENODEV;
+ goto exit;
+ }
+
+ info.complete = &done;
+ info.apicid = apicid;
+ info.cpu = cpu;
+ INIT_WORK(&task, do_warm_boot_cpu, &info);
+
+ tsc_sync_disabled = 1;
+
+ /* init low mem mapping */
+ memcpy(swapper_pg_dir, swapper_pg_dir + USER_PGD_PTRS,
+ sizeof(swapper_pg_dir[0]) * KERNEL_PGD_PTRS);
+ flush_tlb_all();
+ schedule_work(&task);
+ wait_for_completion(&done);
+
+ tsc_sync_disabled = 0;
+ zap_low_mappings();
+ ret = 0;
+exit:
+ unlock_cpu_hotplug();
+ return ret;
+}
+#endif
+
static void smp_tune_scheduling (void)
{
unsigned long cachesize; /* kB */
@@ -895,13 +1073,6 @@ void *xquad_portio;
EXPORT_SYMBOL(xquad_portio);
#endif
-cpumask_t cpu_sibling_map[NR_CPUS] __cacheline_aligned;
-#ifdef CONFIG_X86_HT
-EXPORT_SYMBOL(cpu_sibling_map);
-#endif
-cpumask_t cpu_core_map[NR_CPUS] __cacheline_aligned;
-EXPORT_SYMBOL(cpu_core_map);
-
static void __init smp_boot_cpus(unsigned int max_cpus)
{
int apicid, cpu, bit, kicked;
@@ -1013,7 +1184,7 @@ static void __init smp_boot_cpus(unsigned int max_cpus)
if (max_cpus <= cpucount+1)
continue;
- if (do_boot_cpu(apicid))
+ if (((cpu = alloc_cpu_id()) <= 0) || do_boot_cpu(apicid, cpu))
printk("CPU #%d not responding - cannot use it.\n",
apicid);
else
@@ -1065,44 +1236,8 @@ static void __init smp_boot_cpus(unsigned int max_cpus)
cpus_clear(cpu_core_map[cpu]);
}
- for (cpu = 0; cpu < NR_CPUS; cpu++) {
- struct cpuinfo_x86 *c = cpu_data + cpu;
- int siblings = 0;
- int i;
- if (!cpu_isset(cpu, cpu_callout_map))
- continue;
-
- if (smp_num_siblings > 1) {
- for (i = 0; i < NR_CPUS; i++) {
- if (!cpu_isset(i, cpu_callout_map))
- continue;
- if (cpu_core_id[cpu] == cpu_core_id[i]) {
- siblings++;
- cpu_set(i, cpu_sibling_map[cpu]);
- }
- }
- } else {
- siblings++;
- cpu_set(cpu, cpu_sibling_map[cpu]);
- }
-
- if (siblings != smp_num_siblings) {
- printk(KERN_WARNING "WARNING: %d siblings found for CPU%d, should be %d\n", siblings, cpu, smp_num_siblings);
- smp_num_siblings = siblings;
- }
-
- if (c->x86_num_cores > 1) {
- for (i = 0; i < NR_CPUS; i++) {
- if (!cpu_isset(i, cpu_callout_map))
- continue;
- if (phys_proc_id[cpu] == phys_proc_id[i]) {
- cpu_set(i, cpu_core_map[cpu]);
- }
- }
- } else {
- cpu_core_map[cpu] = cpu_sibling_map[cpu];
- }
- }
+ cpu_set(0, cpu_sibling_map[0]);
+ cpu_set(0, cpu_core_map[0]);
smpboot_setup_io_apic();
@@ -1119,6 +1254,9 @@ static void __init smp_boot_cpus(unsigned int max_cpus)
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);
}
@@ -1126,23 +1264,98 @@ void __devinit smp_prepare_boot_cpu(void)
{
cpu_set(smp_processor_id(), cpu_online_map);
cpu_set(smp_processor_id(), cpu_callout_map);
+ cpu_set(smp_processor_id(), cpu_present_map);
+ per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
}
-int __devinit __cpu_up(unsigned int cpu)
+#ifdef CONFIG_HOTPLUG_CPU
+static void
+remove_siblinginfo(int cpu)
{
- /* This only works at boot for x86. See "rewrite" above. */
- if (cpu_isset(cpu, smp_commenced_mask)) {
- local_irq_enable();
- return -ENOSYS;
+ int sibling;
+
+ for_each_cpu_mask(sibling, cpu_sibling_map[cpu])
+ cpu_clear(cpu, cpu_sibling_map[sibling]);
+ for_each_cpu_mask(sibling, cpu_core_map[cpu])
+ cpu_clear(cpu, cpu_core_map[sibling]);
+ cpus_clear(cpu_sibling_map[cpu]);
+ cpus_clear(cpu_core_map[cpu]);
+ phys_proc_id[cpu] = BAD_APICID;
+ cpu_core_id[cpu] = BAD_APICID;
+}
+
+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();
+
+ remove_siblinginfo(cpu);
+
+ 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) {
+ printk ("CPU %d is now offline\n", cpu);
+ 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;
}
local_irq_enable();
+ per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
/* Unleash the CPU! */
cpu_set(cpu, smp_commenced_mask);
while (!cpu_isset(cpu, cpu_online_map))
@@ -1156,10 +1369,12 @@ void __init smp_cpus_done(unsigned int max_cpus)
setup_ioapic_dest();
#endif
zap_low_mappings();
+#ifndef CONFIG_HOTPLUG_CPU
/*
* Disable executability of the SMP trampoline:
*/
set_kernel_exec((unsigned long)trampoline_base, trampoline_exec);
+#endif
}
void __init smp_intr_init(void)
generated by cgit v1.2.3 (git 2.25.1) at 2024-08-10 14:11:12 +0000