summaryrefslogtreecommitdiff
path: root/arch/ia64/kernel/smp.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/ia64/kernel/smp.c')
-rw-r--r--arch/ia64/kernel/smp.c376
1 files changed, 376 insertions, 0 deletions
diff --git a/arch/ia64/kernel/smp.c b/arch/ia64/kernel/smp.c
new file mode 100644
index 000000000000..953095e2ce15
--- /dev/null
+++ b/arch/ia64/kernel/smp.c
@@ -0,0 +1,376 @@
+/*
+ * SMP Support
+ *
+ * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
+ * Copyright (C) 1999, 2001, 2003 David Mosberger-Tang <davidm@hpl.hp.com>
+ *
+ * Lots of stuff stolen from arch/alpha/kernel/smp.c
+ *
+ * 01/05/16 Rohit Seth <rohit.seth@intel.com> IA64-SMP functions. Reorganized
+ * the existing code (on the lines of x86 port).
+ * 00/09/11 David Mosberger <davidm@hpl.hp.com> Do loops_per_jiffy
+ * calibration on each CPU.
+ * 00/08/23 Asit Mallick <asit.k.mallick@intel.com> fixed logical processor id
+ * 00/03/31 Rohit Seth <rohit.seth@intel.com> Fixes for Bootstrap Processor
+ * & cpu_online_map now gets done here (instead of setup.c)
+ * 99/10/05 davidm Update to bring it in sync with new command-line processing
+ * scheme.
+ * 10/13/00 Goutham Rao <goutham.rao@intel.com> Updated smp_call_function and
+ * smp_call_function_single to resend IPI on timeouts
+ */
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/smp.h>
+#include <linux/kernel_stat.h>
+#include <linux/mm.h>
+#include <linux/cache.h>
+#include <linux/delay.h>
+#include <linux/efi.h>
+#include <linux/bitops.h>
+
+#include <asm/atomic.h>
+#include <asm/current.h>
+#include <asm/delay.h>
+#include <asm/machvec.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/page.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+#include <asm/processor.h>
+#include <asm/ptrace.h>
+#include <asm/sal.h>
+#include <asm/system.h>
+#include <asm/tlbflush.h>
+#include <asm/unistd.h>
+#include <asm/mca.h>
+
+/*
+ * Structure and data for smp_call_function(). This is designed to minimise static memory
+ * requirements. It also looks cleaner.
+ */
+static __cacheline_aligned DEFINE_SPINLOCK(call_lock);
+
+struct call_data_struct {
+ void (*func) (void *info);
+ void *info;
+ long wait;
+ atomic_t started;
+ atomic_t finished;
+};
+
+static volatile struct call_data_struct *call_data;
+
+#define IPI_CALL_FUNC 0
+#define IPI_CPU_STOP 1
+
+/* This needs to be cacheline aligned because it is written to by *other* CPUs. */
+static DEFINE_PER_CPU(u64, ipi_operation) ____cacheline_aligned;
+
+extern void cpu_halt (void);
+
+void
+lock_ipi_calllock(void)
+{
+ spin_lock_irq(&call_lock);
+}
+
+void
+unlock_ipi_calllock(void)
+{
+ spin_unlock_irq(&call_lock);
+}
+
+static void
+stop_this_cpu (void)
+{
+ /*
+ * Remove this CPU:
+ */
+ cpu_clear(smp_processor_id(), cpu_online_map);
+ max_xtp();
+ local_irq_disable();
+ cpu_halt();
+}
+
+void
+cpu_die(void)
+{
+ max_xtp();
+ local_irq_disable();
+ cpu_halt();
+ /* Should never be here */
+ BUG();
+ for (;;);
+}
+
+irqreturn_t
+handle_IPI (int irq, void *dev_id, struct pt_regs *regs)
+{
+ int this_cpu = get_cpu();
+ unsigned long *pending_ipis = &__ia64_per_cpu_var(ipi_operation);
+ unsigned long ops;
+
+ mb(); /* Order interrupt and bit testing. */
+ while ((ops = xchg(pending_ipis, 0)) != 0) {
+ mb(); /* Order bit clearing and data access. */
+ do {
+ unsigned long which;
+
+ which = ffz(~ops);
+ ops &= ~(1 << which);
+
+ switch (which) {
+ case IPI_CALL_FUNC:
+ {
+ struct call_data_struct *data;
+ void (*func)(void *info);
+ void *info;
+ int wait;
+
+ /* release the 'pointer lock' */
+ data = (struct call_data_struct *) call_data;
+ func = data->func;
+ info = data->info;
+ wait = data->wait;
+
+ mb();
+ atomic_inc(&data->started);
+ /*
+ * At this point the structure may be gone unless
+ * wait is true.
+ */
+ (*func)(info);
+
+ /* Notify the sending CPU that the task is done. */
+ mb();
+ if (wait)
+ atomic_inc(&data->finished);
+ }
+ break;
+
+ case IPI_CPU_STOP:
+ stop_this_cpu();
+ break;
+
+ default:
+ printk(KERN_CRIT "Unknown IPI on CPU %d: %lu\n", this_cpu, which);
+ break;
+ }
+ } while (ops);
+ mb(); /* Order data access and bit testing. */
+ }
+ put_cpu();
+ return IRQ_HANDLED;
+}
+
+/*
+ * Called with preeemption disabled.
+ */
+static inline void
+send_IPI_single (int dest_cpu, int op)
+{
+ set_bit(op, &per_cpu(ipi_operation, dest_cpu));
+ platform_send_ipi(dest_cpu, IA64_IPI_VECTOR, IA64_IPI_DM_INT, 0);
+}
+
+/*
+ * Called with preeemption disabled.
+ */
+static inline void
+send_IPI_allbutself (int op)
+{
+ unsigned int i;
+
+ for (i = 0; i < NR_CPUS; i++) {
+ if (cpu_online(i) && i != smp_processor_id())
+ send_IPI_single(i, op);
+ }
+}
+
+/*
+ * Called with preeemption disabled.
+ */
+static inline void
+send_IPI_all (int op)
+{
+ int i;
+
+ for (i = 0; i < NR_CPUS; i++)
+ if (cpu_online(i))
+ send_IPI_single(i, op);
+}
+
+/*
+ * Called with preeemption disabled.
+ */
+static inline void
+send_IPI_self (int op)
+{
+ send_IPI_single(smp_processor_id(), op);
+}
+
+/*
+ * Called with preeemption disabled.
+ */
+void
+smp_send_reschedule (int cpu)
+{
+ platform_send_ipi(cpu, IA64_IPI_RESCHEDULE, IA64_IPI_DM_INT, 0);
+}
+
+void
+smp_flush_tlb_all (void)
+{
+ on_each_cpu((void (*)(void *))local_flush_tlb_all, NULL, 1, 1);
+}
+
+void
+smp_flush_tlb_mm (struct mm_struct *mm)
+{
+ /* this happens for the common case of a single-threaded fork(): */
+ if (likely(mm == current->active_mm && atomic_read(&mm->mm_users) == 1))
+ {
+ local_finish_flush_tlb_mm(mm);
+ return;
+ }
+
+ /*
+ * We could optimize this further by using mm->cpu_vm_mask to track which CPUs
+ * have been running in the address space. It's not clear that this is worth the
+ * trouble though: to avoid races, we have to raise the IPI on the target CPU
+ * anyhow, and once a CPU is interrupted, the cost of local_flush_tlb_all() is
+ * rather trivial.
+ */
+ on_each_cpu((void (*)(void *))local_finish_flush_tlb_mm, mm, 1, 1);
+}
+
+/*
+ * Run a function on another CPU
+ * <func> The function to run. This must be fast and non-blocking.
+ * <info> An arbitrary pointer to pass to the function.
+ * <nonatomic> Currently unused.
+ * <wait> If true, wait until function has completed on other CPUs.
+ * [RETURNS] 0 on success, else a negative status code.
+ *
+ * Does not return until the remote CPU is nearly ready to execute <func>
+ * or is or has executed.
+ */
+
+int
+smp_call_function_single (int cpuid, void (*func) (void *info), void *info, int nonatomic,
+ int wait)
+{
+ struct call_data_struct data;
+ int cpus = 1;
+ int me = get_cpu(); /* prevent preemption and reschedule on another processor */
+
+ if (cpuid == me) {
+ printk("%s: trying to call self\n", __FUNCTION__);
+ put_cpu();
+ return -EBUSY;
+ }
+
+ data.func = func;
+ data.info = info;
+ atomic_set(&data.started, 0);
+ data.wait = wait;
+ if (wait)
+ atomic_set(&data.finished, 0);
+
+ spin_lock_bh(&call_lock);
+
+ call_data = &data;
+ mb(); /* ensure store to call_data precedes setting of IPI_CALL_FUNC */
+ send_IPI_single(cpuid, IPI_CALL_FUNC);
+
+ /* Wait for response */
+ while (atomic_read(&data.started) != cpus)
+ cpu_relax();
+
+ if (wait)
+ while (atomic_read(&data.finished) != cpus)
+ cpu_relax();
+ call_data = NULL;
+
+ spin_unlock_bh(&call_lock);
+ put_cpu();
+ return 0;
+}
+EXPORT_SYMBOL(smp_call_function_single);
+
+/*
+ * this function sends a 'generic call function' IPI to all other CPUs
+ * in the system.
+ */
+
+/*
+ * [SUMMARY] Run a function on all other CPUs.
+ * <func> The function to run. This must be fast and non-blocking.
+ * <info> An arbitrary pointer to pass to the function.
+ * <nonatomic> currently unused.
+ * <wait> If true, wait (atomically) until function has completed on other CPUs.
+ * [RETURNS] 0 on success, else a negative status code.
+ *
+ * Does not return until remote CPUs are nearly ready to execute <func> or are or have
+ * executed.
+ *
+ * You must not call this function with disabled interrupts or from a
+ * hardware interrupt handler or from a bottom half handler.
+ */
+int
+smp_call_function (void (*func) (void *info), void *info, int nonatomic, int wait)
+{
+ struct call_data_struct data;
+ int cpus = num_online_cpus()-1;
+
+ if (!cpus)
+ return 0;
+
+ /* Can deadlock when called with interrupts disabled */
+ WARN_ON(irqs_disabled());
+
+ data.func = func;
+ data.info = info;
+ atomic_set(&data.started, 0);
+ data.wait = wait;
+ if (wait)
+ atomic_set(&data.finished, 0);
+
+ spin_lock(&call_lock);
+
+ call_data = &data;
+ mb(); /* ensure store to call_data precedes setting of IPI_CALL_FUNC */
+ send_IPI_allbutself(IPI_CALL_FUNC);
+
+ /* Wait for response */
+ while (atomic_read(&data.started) != cpus)
+ cpu_relax();
+
+ if (wait)
+ while (atomic_read(&data.finished) != cpus)
+ cpu_relax();
+ call_data = NULL;
+
+ spin_unlock(&call_lock);
+ return 0;
+}
+EXPORT_SYMBOL(smp_call_function);
+
+/*
+ * this function calls the 'stop' function on all other CPUs in the system.
+ */
+void
+smp_send_stop (void)
+{
+ send_IPI_allbutself(IPI_CPU_STOP);
+}
+
+int __init
+setup_profiling_timer (unsigned int multiplier)
+{
+ return -EINVAL;
+}