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-rw-r--r--arch/arm/kernel/smp.c409
1 files changed, 157 insertions, 252 deletions
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index b6b78b22031b..5ec79b4ff950 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -25,6 +25,7 @@
#include <linux/irq.h>
#include <linux/percpu.h>
#include <linux/clockchips.h>
+#include <linux/completion.h>
#include <asm/atomic.h>
#include <asm/cacheflush.h>
@@ -38,7 +39,6 @@
#include <asm/tlbflush.h>
#include <asm/ptrace.h>
#include <asm/localtimer.h>
-#include <asm/smp_plat.h>
/*
* as from 2.5, kernels no longer have an init_tasks structure
@@ -47,22 +47,8 @@
*/
struct secondary_data secondary_data;
-/*
- * structures for inter-processor calls
- * - A collection of single bit ipi messages.
- */
-struct ipi_data {
- spinlock_t lock;
- unsigned long ipi_count;
- unsigned long bits;
-};
-
-static DEFINE_PER_CPU(struct ipi_data, ipi_data) = {
- .lock = SPIN_LOCK_UNLOCKED,
-};
-
enum ipi_msg_type {
- IPI_TIMER,
+ IPI_TIMER = 2,
IPI_RESCHEDULE,
IPI_CALL_FUNC,
IPI_CALL_FUNC_SINGLE,
@@ -178,8 +164,12 @@ int __cpuinit __cpu_up(unsigned int cpu)
barrier();
}
- if (!cpu_online(cpu))
+ if (!cpu_online(cpu)) {
+ pr_crit("CPU%u: failed to come online\n", cpu);
ret = -EIO;
+ }
+ } else {
+ pr_err("CPU%u: failed to boot: %d\n", cpu, ret);
}
secondary_data.stack = NULL;
@@ -195,18 +185,12 @@ int __cpuinit __cpu_up(unsigned int cpu)
pgd_free(&init_mm, pgd);
- if (ret) {
- printk(KERN_CRIT "CPU%u: processor failed to boot\n", cpu);
-
- /*
- * FIXME: We need to clean up the new idle thread. --rmk
- */
- }
-
return ret;
}
#ifdef CONFIG_HOTPLUG_CPU
+static void percpu_timer_stop(void);
+
/*
* __cpu_disable runs on the processor to be shutdown.
*/
@@ -234,7 +218,7 @@ int __cpu_disable(void)
/*
* Stop the local timer for this CPU.
*/
- local_timer_stop();
+ percpu_timer_stop();
/*
* Flush user cache and TLB mappings, and then remove this CPU
@@ -253,12 +237,20 @@ int __cpu_disable(void)
return 0;
}
+static DECLARE_COMPLETION(cpu_died);
+
/*
* called on the thread which is asking for a CPU to be shutdown -
* waits until shutdown has completed, or it is timed out.
*/
void __cpu_die(unsigned int cpu)
{
+ if (!wait_for_completion_timeout(&cpu_died, msecs_to_jiffies(5000))) {
+ pr_err("CPU%u: cpu didn't die\n", cpu);
+ return;
+ }
+ printk(KERN_NOTICE "CPU%u: shutdown\n", cpu);
+
if (!platform_cpu_kill(cpu))
printk("CPU%u: unable to kill\n", cpu);
}
@@ -275,12 +267,17 @@ void __ref cpu_die(void)
{
unsigned int cpu = smp_processor_id();
- local_irq_disable();
idle_task_exit();
+ local_irq_disable();
+ mb();
+
+ /* Tell __cpu_die() that this CPU is now safe to dispose of */
+ complete(&cpu_died);
+
/*
* actual CPU shutdown procedure is at least platform (if not
- * CPU) specific
+ * CPU) specific.
*/
platform_cpu_die(cpu);
@@ -290,6 +287,7 @@ void __ref cpu_die(void)
* to be repeated to undo the effects of taking the CPU offline.
*/
__asm__("mov sp, %0\n"
+ " mov fp, #0\n"
" b secondary_start_kernel"
:
: "r" (task_stack_page(current) + THREAD_SIZE - 8));
@@ -297,6 +295,17 @@ void __ref cpu_die(void)
#endif /* CONFIG_HOTPLUG_CPU */
/*
+ * Called by both boot and secondaries to move global data into
+ * per-processor storage.
+ */
+static void __cpuinit smp_store_cpu_info(unsigned int cpuid)
+{
+ struct cpuinfo_arm *cpu_info = &per_cpu(cpu_data, cpuid);
+
+ cpu_info->loops_per_jiffy = loops_per_jiffy;
+}
+
+/*
* This is the secondary CPU boot entry. We're using this CPUs
* idle thread stack, but a set of temporary page tables.
*/
@@ -320,6 +329,7 @@ asmlinkage void __cpuinit secondary_start_kernel(void)
cpu_init();
preempt_disable();
+ trace_hardirqs_off();
/*
* Give the platform a chance to do its own initialisation.
@@ -353,17 +363,6 @@ asmlinkage void __cpuinit secondary_start_kernel(void)
cpu_idle();
}
-/*
- * Called by both boot and secondaries to move global data into
- * per-processor storage.
- */
-void __cpuinit smp_store_cpu_info(unsigned int cpuid)
-{
- struct cpuinfo_arm *cpu_info = &per_cpu(cpu_data, cpuid);
-
- cpu_info->loops_per_jiffy = loops_per_jiffy;
-}
-
void __init smp_cpus_done(unsigned int max_cpus)
{
int cpu;
@@ -386,61 +385,80 @@ void __init smp_prepare_boot_cpu(void)
per_cpu(cpu_data, cpu).idle = current;
}
-static void send_ipi_message(const struct cpumask *mask, enum ipi_msg_type msg)
+void __init smp_prepare_cpus(unsigned int max_cpus)
{
- unsigned long flags;
- unsigned int cpu;
-
- local_irq_save(flags);
+ unsigned int ncores = num_possible_cpus();
- for_each_cpu(cpu, mask) {
- struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
-
- spin_lock(&ipi->lock);
- ipi->bits |= 1 << msg;
- spin_unlock(&ipi->lock);
- }
+ smp_store_cpu_info(smp_processor_id());
/*
- * Call the platform specific cross-CPU call function.
+ * are we trying to boot more cores than exist?
*/
- smp_cross_call(mask);
+ if (max_cpus > ncores)
+ max_cpus = ncores;
+
+ if (max_cpus > 1) {
+ /*
+ * Enable the local timer or broadcast device for the
+ * boot CPU, but only if we have more than one CPU.
+ */
+ percpu_timer_setup();
- local_irq_restore(flags);
+ /*
+ * Initialise the SCU if there are more than one CPU
+ * and let them know where to start.
+ */
+ platform_smp_prepare_cpus(max_cpus);
+ }
}
void arch_send_call_function_ipi_mask(const struct cpumask *mask)
{
- send_ipi_message(mask, IPI_CALL_FUNC);
+ smp_cross_call(mask, IPI_CALL_FUNC);
}
void arch_send_call_function_single_ipi(int cpu)
{
- send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE);
+ smp_cross_call(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE);
}
-void show_ipi_list(struct seq_file *p)
+static const char *ipi_types[NR_IPI] = {
+#define S(x,s) [x - IPI_TIMER] = s
+ S(IPI_TIMER, "Timer broadcast interrupts"),
+ S(IPI_RESCHEDULE, "Rescheduling interrupts"),
+ S(IPI_CALL_FUNC, "Function call interrupts"),
+ S(IPI_CALL_FUNC_SINGLE, "Single function call interrupts"),
+ S(IPI_CPU_STOP, "CPU stop interrupts"),
+};
+
+void show_ipi_list(struct seq_file *p, int prec)
{
- unsigned int cpu;
+ unsigned int cpu, i;
- seq_puts(p, "IPI:");
+ for (i = 0; i < NR_IPI; i++) {
+ seq_printf(p, "%*s%u: ", prec - 1, "IPI", i);
- for_each_present_cpu(cpu)
- seq_printf(p, " %10lu", per_cpu(ipi_data, cpu).ipi_count);
+ for_each_present_cpu(cpu)
+ seq_printf(p, "%10u ",
+ __get_irq_stat(cpu, ipi_irqs[i]));
- seq_putc(p, '\n');
+ seq_printf(p, " %s\n", ipi_types[i]);
+ }
}
-void show_local_irqs(struct seq_file *p)
+u64 smp_irq_stat_cpu(unsigned int cpu)
{
- unsigned int cpu;
+ u64 sum = 0;
+ int i;
- seq_printf(p, "LOC: ");
+ for (i = 0; i < NR_IPI; i++)
+ sum += __get_irq_stat(cpu, ipi_irqs[i]);
- for_each_present_cpu(cpu)
- seq_printf(p, "%10u ", irq_stat[cpu].local_timer_irqs);
+#ifdef CONFIG_LOCAL_TIMERS
+ sum += __get_irq_stat(cpu, local_timer_irqs);
+#endif
- seq_putc(p, '\n');
+ return sum;
}
/*
@@ -463,18 +481,30 @@ asmlinkage void __exception_irq_entry do_local_timer(struct pt_regs *regs)
int cpu = smp_processor_id();
if (local_timer_ack()) {
- irq_stat[cpu].local_timer_irqs++;
+ __inc_irq_stat(cpu, local_timer_irqs);
ipi_timer();
}
set_irq_regs(old_regs);
}
+
+void show_local_irqs(struct seq_file *p, int prec)
+{
+ unsigned int cpu;
+
+ seq_printf(p, "%*s: ", prec, "LOC");
+
+ for_each_present_cpu(cpu)
+ seq_printf(p, "%10u ", __get_irq_stat(cpu, local_timer_irqs));
+
+ seq_printf(p, " Local timer interrupts\n");
+}
#endif
#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
static void smp_timer_broadcast(const struct cpumask *mask)
{
- send_ipi_message(mask, IPI_TIMER);
+ smp_cross_call(mask, IPI_TIMER);
}
#else
#define smp_timer_broadcast NULL
@@ -511,6 +541,21 @@ void __cpuinit percpu_timer_setup(void)
local_timer_setup(evt);
}
+#ifdef CONFIG_HOTPLUG_CPU
+/*
+ * The generic clock events code purposely does not stop the local timer
+ * on CPU_DEAD/CPU_DEAD_FROZEN hotplug events, so we have to do it
+ * manually here.
+ */
+static void percpu_timer_stop(void)
+{
+ unsigned int cpu = smp_processor_id();
+ struct clock_event_device *evt = &per_cpu(percpu_clockevent, cpu);
+
+ evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt);
+}
+#endif
+
static DEFINE_SPINLOCK(stop_lock);
/*
@@ -537,216 +582,76 @@ static void ipi_cpu_stop(unsigned int cpu)
/*
* Main handler for inter-processor interrupts
- *
- * For ARM, the ipimask now only identifies a single
- * category of IPI (Bit 1 IPIs have been replaced by a
- * different mechanism):
- *
- * Bit 0 - Inter-processor function call
*/
-asmlinkage void __exception_irq_entry do_IPI(struct pt_regs *regs)
+asmlinkage void __exception_irq_entry do_IPI(int ipinr, struct pt_regs *regs)
{
unsigned int cpu = smp_processor_id();
- struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
struct pt_regs *old_regs = set_irq_regs(regs);
- ipi->ipi_count++;
-
- for (;;) {
- unsigned long msgs;
+ if (ipinr >= IPI_TIMER && ipinr < IPI_TIMER + NR_IPI)
+ __inc_irq_stat(cpu, ipi_irqs[ipinr - IPI_TIMER]);
- spin_lock(&ipi->lock);
- msgs = ipi->bits;
- ipi->bits = 0;
- spin_unlock(&ipi->lock);
-
- if (!msgs)
- break;
-
- do {
- unsigned nextmsg;
-
- nextmsg = msgs & -msgs;
- msgs &= ~nextmsg;
- nextmsg = ffz(~nextmsg);
-
- switch (nextmsg) {
- case IPI_TIMER:
- ipi_timer();
- break;
+ switch (ipinr) {
+ case IPI_TIMER:
+ ipi_timer();
+ break;
- case IPI_RESCHEDULE:
- /*
- * nothing more to do - eveything is
- * done on the interrupt return path
- */
- break;
+ case IPI_RESCHEDULE:
+ /*
+ * nothing more to do - eveything is
+ * done on the interrupt return path
+ */
+ break;
- case IPI_CALL_FUNC:
- generic_smp_call_function_interrupt();
- break;
+ case IPI_CALL_FUNC:
+ generic_smp_call_function_interrupt();
+ break;
- case IPI_CALL_FUNC_SINGLE:
- generic_smp_call_function_single_interrupt();
- break;
+ case IPI_CALL_FUNC_SINGLE:
+ generic_smp_call_function_single_interrupt();
+ break;
- case IPI_CPU_STOP:
- ipi_cpu_stop(cpu);
- break;
+ case IPI_CPU_STOP:
+ ipi_cpu_stop(cpu);
+ break;
- default:
- printk(KERN_CRIT "CPU%u: Unknown IPI message 0x%x\n",
- cpu, nextmsg);
- break;
- }
- } while (msgs);
+ default:
+ printk(KERN_CRIT "CPU%u: Unknown IPI message 0x%x\n",
+ cpu, ipinr);
+ break;
}
-
set_irq_regs(old_regs);
}
void smp_send_reschedule(int cpu)
{
- send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE);
+ smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE);
}
void smp_send_stop(void)
{
- cpumask_t mask = cpu_online_map;
- cpu_clear(smp_processor_id(), mask);
- if (!cpus_empty(mask))
- send_ipi_message(&mask, IPI_CPU_STOP);
-}
+ unsigned long timeout;
-/*
- * not supported here
- */
-int setup_profiling_timer(unsigned int multiplier)
-{
- return -EINVAL;
-}
+ if (num_online_cpus() > 1) {
+ cpumask_t mask = cpu_online_map;
+ cpu_clear(smp_processor_id(), mask);
-static void
-on_each_cpu_mask(void (*func)(void *), void *info, int wait,
- const struct cpumask *mask)
-{
- preempt_disable();
+ smp_cross_call(&mask, IPI_CPU_STOP);
+ }
- smp_call_function_many(mask, func, info, wait);
- if (cpumask_test_cpu(smp_processor_id(), mask))
- func(info);
+ /* Wait up to one second for other CPUs to stop */
+ timeout = USEC_PER_SEC;
+ while (num_online_cpus() > 1 && timeout--)
+ udelay(1);
- preempt_enable();
+ if (num_online_cpus() > 1)
+ pr_warning("SMP: failed to stop secondary CPUs\n");
}
-/**********************************************************************/
-
/*
- * TLB operations
+ * not supported here
*/
-struct tlb_args {
- struct vm_area_struct *ta_vma;
- unsigned long ta_start;
- unsigned long ta_end;
-};
-
-static inline void ipi_flush_tlb_all(void *ignored)
-{
- local_flush_tlb_all();
-}
-
-static inline void ipi_flush_tlb_mm(void *arg)
-{
- struct mm_struct *mm = (struct mm_struct *)arg;
-
- local_flush_tlb_mm(mm);
-}
-
-static inline void ipi_flush_tlb_page(void *arg)
-{
- struct tlb_args *ta = (struct tlb_args *)arg;
-
- local_flush_tlb_page(ta->ta_vma, ta->ta_start);
-}
-
-static inline void ipi_flush_tlb_kernel_page(void *arg)
-{
- struct tlb_args *ta = (struct tlb_args *)arg;
-
- local_flush_tlb_kernel_page(ta->ta_start);
-}
-
-static inline void ipi_flush_tlb_range(void *arg)
-{
- struct tlb_args *ta = (struct tlb_args *)arg;
-
- local_flush_tlb_range(ta->ta_vma, ta->ta_start, ta->ta_end);
-}
-
-static inline void ipi_flush_tlb_kernel_range(void *arg)
-{
- struct tlb_args *ta = (struct tlb_args *)arg;
-
- local_flush_tlb_kernel_range(ta->ta_start, ta->ta_end);
-}
-
-void flush_tlb_all(void)
-{
- if (tlb_ops_need_broadcast())
- on_each_cpu(ipi_flush_tlb_all, NULL, 1);
- else
- local_flush_tlb_all();
-}
-
-void flush_tlb_mm(struct mm_struct *mm)
-{
- if (tlb_ops_need_broadcast())
- on_each_cpu_mask(ipi_flush_tlb_mm, mm, 1, mm_cpumask(mm));
- else
- local_flush_tlb_mm(mm);
-}
-
-void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)
-{
- if (tlb_ops_need_broadcast()) {
- struct tlb_args ta;
- ta.ta_vma = vma;
- ta.ta_start = uaddr;
- on_each_cpu_mask(ipi_flush_tlb_page, &ta, 1, mm_cpumask(vma->vm_mm));
- } else
- local_flush_tlb_page(vma, uaddr);
-}
-
-void flush_tlb_kernel_page(unsigned long kaddr)
-{
- if (tlb_ops_need_broadcast()) {
- struct tlb_args ta;
- ta.ta_start = kaddr;
- on_each_cpu(ipi_flush_tlb_kernel_page, &ta, 1);
- } else
- local_flush_tlb_kernel_page(kaddr);
-}
-
-void flush_tlb_range(struct vm_area_struct *vma,
- unsigned long start, unsigned long end)
-{
- if (tlb_ops_need_broadcast()) {
- struct tlb_args ta;
- ta.ta_vma = vma;
- ta.ta_start = start;
- ta.ta_end = end;
- on_each_cpu_mask(ipi_flush_tlb_range, &ta, 1, mm_cpumask(vma->vm_mm));
- } else
- local_flush_tlb_range(vma, start, end);
-}
-
-void flush_tlb_kernel_range(unsigned long start, unsigned long end)
+int setup_profiling_timer(unsigned int multiplier)
{
- if (tlb_ops_need_broadcast()) {
- struct tlb_args ta;
- ta.ta_start = start;
- ta.ta_end = end;
- on_each_cpu(ipi_flush_tlb_kernel_range, &ta, 1);
- } else
- local_flush_tlb_kernel_range(start, end);
+ return -EINVAL;
}