* Andi Kleen : Converted to new state machine.
* Various cleanups.
* Probably mostly hotplug CPU ready now.
+ * Ashok Raj : CPU hotplug support
*/
#include <asm/proto.h>
#include <asm/nmi.h>
-/* Change for real CPU hotplug. Note other files need to be fixed
- first too. */
-#define __cpuinit __init
-#define __cpuinitdata __initdata
-
/* Number of siblings per CPU package */
int smp_num_siblings = 1;
/* Package ID of each logical CPU */
extern unsigned char trampoline_data[];
extern unsigned char trampoline_end[];
+/* State of each CPU */
+DEFINE_PER_CPU(int, cpu_state) = { 0 };
+
+/*
+ * 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] __cpuinitdata ;
+
+#define get_idle_for_cpu(x) (idle_thread_array[(x)])
+#define set_idle_for_cpu(x,p) (idle_thread_array[(x)] = (p))
+
/*
* Currently trivial. Write the real->protected mode
* bootstrap into the page concerned. The caller
{
unsigned long flags, i;
- if (smp_processor_id() != boot_cpu_id)
- return;
-
go[MASTER] = 0;
local_irq_save(flags);
return tcenter - best_tm;
}
-static __cpuinit void sync_tsc(void)
+static __cpuinit void sync_tsc(unsigned int master)
{
int i, done = 0;
long delta, adj, adjust_latency = 0;
unsigned long flags, rt, master_time_stamp, bound;
-#if DEBUG_TSC_SYNC
+#ifdef DEBUG_TSC_SYNC
static struct syncdebug {
long rt; /* roundtrip time */
long master; /* master's timestamp */
} t[NUM_ROUNDS] __cpuinitdata;
#endif
+ printk(KERN_INFO "CPU %d: Syncing TSC to CPU %u.\n",
+ smp_processor_id(), master);
+
go[MASTER] = 1;
- smp_call_function(sync_master, NULL, 1, 0);
+ /* It is dangerous to broadcast IPI as cpus are coming up,
+ * as they may not be ready to accept them. So since
+ * we only need to send the ipi to the boot cpu direct
+ * the message, and avoid the race.
+ */
+ smp_call_function_single(master, sync_master, NULL, 1, 0);
while (go[MASTER]) /* wait for master to be ready */
no_cpu_relax();
rdtscll(t);
wrmsrl(MSR_IA32_TSC, t + adj);
}
-#if DEBUG_TSC_SYNC
+#ifdef DEBUG_TSC_SYNC
t[i].rt = rt;
t[i].master = master_time_stamp;
t[i].diff = delta;
}
spin_unlock_irqrestore(&tsc_sync_lock, flags);
-#if DEBUG_TSC_SYNC
+#ifdef DEBUG_TSC_SYNC
for (i = 0; i < NUM_ROUNDS; ++i)
printk("rt=%5ld master=%5ld diff=%5ld adjlat=%5ld\n",
t[i].rt, t[i].master, t[i].diff, t[i].lat);
printk(KERN_INFO
"CPU %d: synchronized TSC with CPU %u (last diff %ld cycles, "
"maxerr %lu cycles)\n",
- smp_processor_id(), boot_cpu_id, delta, rt);
+ smp_processor_id(), master, delta, rt);
}
static void __cpuinit tsc_sync_wait(void)
{
if (notscsync || !cpu_has_tsc)
return;
- printk(KERN_INFO "CPU %d: Syncing TSC to CPU %u.\n", smp_processor_id(),
- boot_cpu_id);
- sync_tsc();
+ sync_tsc(0);
}
static __init int notscsync_setup(char *s)
cpu_set(cpuid, cpu_callin_map);
}
+static inline void set_cpu_sibling_map(int cpu)
+{
+ int i;
+
+ if (smp_num_siblings > 1) {
+ for_each_cpu(i) {
+ 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_each_cpu(i) {
+ 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];
+ }
+}
+
/*
* Setup code on secondary processor (after comming out of the trampoline)
*/
enable_APIC_timer();
+ /*
+ * The sibling maps must be set before turing the online map on for
+ * this cpu
+ */
+ set_cpu_sibling_map(smp_processor_id());
+
+ /*
+ * Wait for TSC sync to not schedule things before.
+ * We still process interrupts, which could see an inconsistent
+ * time in that window unfortunately.
+ * Do this here because TSC sync has global unprotected state.
+ */
+ tsc_sync_wait();
+
+ /*
+ * 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 in genapic_flat.c. Holding this
+ * lock helps us to not include this cpu in a currently in progress
+ * smp_call_function().
+ */
+ lock_ipi_call_lock();
+
/*
* Allow the master to continue.
*/
cpu_set(smp_processor_id(), cpu_online_map);
- mb();
-
- /* Wait for TSC sync to not schedule things before.
- We still process interrupts, which could see an inconsistent
- time in that window unfortunately. */
- tsc_sync_wait();
+ per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
+ unlock_ipi_call_lock();
cpu_idle();
}
extern volatile unsigned long init_rsp;
extern void (*initial_code)(void);
-#if APIC_DEBUG
+#ifdef APIC_DEBUG
static void inquire_remote_apic(int apicid)
{
unsigned i, regs[] = { APIC_ID >> 4, APIC_LVR >> 4, APIC_SPIV >> 4 };
return (send_status | accept_status);
}
+struct create_idle {
+ struct task_struct *idle;
+ struct completion done;
+ int cpu;
+};
+
+void do_fork_idle(void *_c_idle)
+{
+ struct create_idle *c_idle = _c_idle;
+
+ c_idle->idle = fork_idle(c_idle->cpu);
+ complete(&c_idle->done);
+}
+
/*
* Boot one CPU.
*/
static int __cpuinit do_boot_cpu(int cpu, int apicid)
{
- struct task_struct *idle;
unsigned long boot_error;
int timeout;
unsigned long start_rip;
+ struct create_idle c_idle = {
+ .cpu = 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) {
+ c_idle.idle->thread.rsp = (unsigned long) (((struct pt_regs *)
+ (THREAD_SIZE + (unsigned long) c_idle.idle->thread_info)) - 1);
+ init_idle(c_idle.idle, cpu);
+ goto do_rest;
+ }
+
/*
- * We can't use kernel_thread since we must avoid to
- * reschedule the child.
+ * During cold boot process, keventd thread is not spun up yet.
+ * When we do cpu hot-add, we create idle threads on the fly, we should
+ * not acquire any attributes from the calling context. Hence the clean
+ * way to create kernel_threads() is to do that from keventd().
+ * We do the current_is_keventd() due to the fact that ACPI notifier
+ * was also queuing to keventd() and when the caller is already running
+ * in context of keventd(), we would end up with locking up the keventd
+ * thread.
*/
- idle = fork_idle(cpu);
- if (IS_ERR(idle)) {
+ if (!keventd_up() || current_is_keventd())
+ work.func(work.data);
+ else {
+ schedule_work(&work);
+ wait_for_completion(&c_idle.done);
+ }
+
+ if (IS_ERR(c_idle.idle)) {
printk("failed fork for CPU %d\n", cpu);
- return PTR_ERR(idle);
+ return PTR_ERR(c_idle.idle);
}
- cpu_pda[cpu].pcurrent = idle;
+ set_idle_for_cpu(cpu, c_idle.idle);
+
+do_rest:
+
+ cpu_pda[cpu].pcurrent = c_idle.idle;
start_rip = setup_trampoline();
- init_rsp = idle->thread.rsp;
+ init_rsp = c_idle.idle->thread.rsp;
per_cpu(init_tss,cpu).rsp0 = init_rsp;
initial_code = start_secondary;
- clear_ti_thread_flag(idle->thread_info, TIF_FORK);
+ clear_ti_thread_flag(c_idle.idle->thread_info, TIF_FORK);
- printk(KERN_INFO "Booting processor %d/%d rip %lx rsp %lx\n", cpu, apicid,
- start_rip, init_rsp);
+ printk(KERN_INFO "Booting processor %d/%d APIC 0x%x\n", cpu,
+ cpus_weight(cpu_present_map),
+ apicid);
/*
* This grunge runs the startup process for
else
/* trampoline code not run */
printk("Not responding.\n");
-#if APIC_DEBUG
+#ifdef APIC_DEBUG
inquire_remote_apic(apicid);
#endif
}
cycles_t cacheflush_time;
unsigned long cache_decay_ticks;
-/*
- * Construct cpu_sibling_map[], so that we can tell the sibling CPU
- * on SMT systems efficiently.
- */
-static __cpuinit void detect_siblings(void)
-{
- int cpu;
-
- for (cpu = 0; cpu < NR_CPUS; cpu++) {
- cpus_clear(cpu_sibling_map[cpu]);
- cpus_clear(cpu_core_map[cpu]);
- }
-
- for_each_online_cpu (cpu) {
- struct cpuinfo_x86 *c = cpu_data + cpu;
- int siblings = 0;
- int i;
- if (smp_num_siblings > 1) {
- for_each_online_cpu (i) {
- 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_each_online_cpu(i) {
- 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];
- }
-}
-
/*
* Cleanup possible dangling ends...
*/
*
* RED-PEN audit/test this more. I bet there is more state messed up here.
*/
-static __cpuinit void disable_smp(void)
+static __init void disable_smp(void)
{
cpu_present_map = cpumask_of_cpu(0);
cpu_possible_map = cpumask_of_cpu(0);
/*
* Handle user cpus=... parameter.
*/
-static __cpuinit void enforce_max_cpus(unsigned max_cpus)
+static __init void enforce_max_cpus(unsigned max_cpus)
{
int i, k;
k = 0;
}
}
+#ifdef CONFIG_HOTPLUG_CPU
+/*
+ * cpu_possible_map should be static, it cannot change as cpu's
+ * are onlined, or offlined. The reason is per-cpu data-structures
+ * are allocated by some modules at init time, and dont expect to
+ * do this dynamically on cpu arrival/departure.
+ * cpu_present_map on the other hand can change dynamically.
+ * In case when cpu_hotplug is not compiled, then we resort to current
+ * behaviour, which is cpu_possible == cpu_present.
+ * If cpu-hotplug is supported, then we need to preallocate for all
+ * those NR_CPUS, hence cpu_possible_map represents entire NR_CPUS range.
+ * - Ashok Raj
+ */
+static void prefill_possible_map(void)
+{
+ int i;
+ for (i = 0; i < NR_CPUS; i++)
+ cpu_set(i, cpu_possible_map);
+}
+#endif
+
/*
* Various sanity checks.
*/
-static int __cpuinit smp_sanity_check(unsigned max_cpus)
+static int __init smp_sanity_check(unsigned max_cpus)
{
if (!physid_isset(hard_smp_processor_id(), phys_cpu_present_map)) {
printk("weird, boot CPU (#%d) not listed by the BIOS.\n",
* Prepare for SMP bootup. The MP table or ACPI has been read
* earlier. Just do some sanity checking here and enable APIC mode.
*/
-void __cpuinit smp_prepare_cpus(unsigned int max_cpus)
+void __init smp_prepare_cpus(unsigned int max_cpus)
{
- int i;
-
nmi_watchdog_default();
current_cpu_data = boot_cpu_data;
current_thread_info()->cpu = 0; /* needed? */
enforce_max_cpus(max_cpus);
- /*
- * Fill in cpu_present_mask
- */
- for (i = 0; i < NR_CPUS; i++) {
- int apicid = cpu_present_to_apicid(i);
- if (physid_isset(apicid, phys_cpu_present_map)) {
- cpu_set(i, cpu_present_map);
- /* possible map would be different if we supported real
- CPU hotplug. */
- cpu_set(i, cpu_possible_map);
- }
- }
+#ifdef CONFIG_HOTPLUG_CPU
+ prefill_possible_map();
+#endif
if (smp_sanity_check(max_cpus) < 0) {
printk(KERN_INFO "SMP disabled\n");
int me = smp_processor_id();
cpu_set(me, cpu_online_map);
cpu_set(me, cpu_callout_map);
+ cpu_set(0, cpu_sibling_map[0]);
+ cpu_set(0, cpu_core_map[0]);
+ per_cpu(cpu_state, me) = CPU_ONLINE;
}
/*
* Entry point to boot a CPU.
- *
- * This is all __cpuinit, not __devinit for now because we don't support
- * CPU hotplug (yet).
*/
int __cpuinit __cpu_up(unsigned int cpu)
{
return -EINVAL;
}
+ /*
+ * Already booted CPU?
+ */
+ if (cpu_isset(cpu, cpu_callin_map)) {
+ Dprintk("do_boot_cpu %d Already started\n", cpu);
+ return -ENOSYS;
+ }
+
+ per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
/* Boot it! */
err = do_boot_cpu(cpu, apicid);
if (err < 0) {
while (!cpu_isset(cpu, cpu_online_map))
cpu_relax();
- return 0;
+ err = 0;
+
+ return err;
}
/*
* Finish the SMP boot.
*/
-void __cpuinit smp_cpus_done(unsigned int max_cpus)
+void __init smp_cpus_done(unsigned int max_cpus)
{
+#ifndef CONFIG_HOTPLUG_CPU
zap_low_mappings();
+#endif
smp_cleanup_boot();
#ifdef CONFIG_X86_IO_APIC
setup_ioapic_dest();
#endif
- detect_siblings();
time_init_gtod();
check_nmi_watchdog();
}
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+static void remove_siblinginfo(int cpu)
+{
+ 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;
+}
+
+void remove_cpu_from_maps(void)
+{
+ int cpu = smp_processor_id();
+
+ cpu_clear(cpu, cpu_callout_map);
+ cpu_clear(cpu, cpu_callin_map);
+ clear_bit(cpu, &cpu_initialized); /* was set by cpu_init() */
+}
+
+int __cpu_disable(void)
+{
+ 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;
+
+ disable_APIC_timer();
+
+ /*
+ * HACK:
+ * Allow any queued timer interrupts to get serviced
+ * This is only a temporary solution until we cleanup
+ * fixup_irqs as we do for IA64.
+ */
+ local_irq_enable();
+ mdelay(1);
+
+ local_irq_disable();
+ remove_siblinginfo(cpu);
+
+ /* It's now safe to remove this processor from the online map */
+ cpu_clear(cpu, cpu_online_map);
+ remove_cpu_from_maps();
+ fixup_irqs(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;
+ }
+ msleep(100);
+ }
+ 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 */
git.openpandora.org / pandora-kernel.git / blobdiff