v4.19.13 snapshot.
diff --git a/arch/ia64/kernel/smp.c b/arch/ia64/kernel/smp.c
new file mode 100644
index 0000000..7f706d4
--- /dev/null
+++ b/arch/ia64/kernel/smp.c
@@ -0,0 +1,342 @@
+/*
+ * 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 <linux/kexec.h>
+
+#include <linux/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/tlbflush.h>
+#include <asm/unistd.h>
+#include <asm/mca.h>
+
+/*
+ * Note: alignment of 4 entries/cacheline was empirically determined
+ * to be a good tradeoff between hot cachelines & spreading the array
+ * across too many cacheline.
+ */
+static struct local_tlb_flush_counts {
+ unsigned int count;
+} __attribute__((__aligned__(32))) local_tlb_flush_counts[NR_CPUS];
+
+static DEFINE_PER_CPU_SHARED_ALIGNED(unsigned short [NR_CPUS],
+ shadow_flush_counts);
+
+#define IPI_CALL_FUNC 0
+#define IPI_CPU_STOP 1
+#define IPI_CALL_FUNC_SINGLE 2
+#define IPI_KDUMP_CPU_STOP 3
+
+/* This needs to be cacheline aligned because it is written to by *other* CPUs. */
+static DEFINE_PER_CPU_SHARED_ALIGNED(unsigned long, ipi_operation);
+
+extern void cpu_halt (void);
+
+static void
+stop_this_cpu(void)
+{
+ /*
+ * Remove this CPU:
+ */
+ set_cpu_online(smp_processor_id(), false);
+ 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)
+{
+ 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_CPU_STOP:
+ stop_this_cpu();
+ break;
+ case IPI_CALL_FUNC:
+ generic_smp_call_function_interrupt();
+ break;
+ case IPI_CALL_FUNC_SINGLE:
+ generic_smp_call_function_single_interrupt();
+ break;
+#ifdef CONFIG_KEXEC
+ case IPI_KDUMP_CPU_STOP:
+ unw_init_running(kdump_cpu_freeze, NULL);
+ break;
+#endif
+ 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 preemption 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 preemption disabled.
+ */
+static inline void
+send_IPI_allbutself (int op)
+{
+ unsigned int i;
+
+ for_each_online_cpu(i) {
+ if (i != smp_processor_id())
+ send_IPI_single(i, op);
+ }
+}
+
+/*
+ * Called with preemption disabled.
+ */
+static inline void
+send_IPI_mask(const struct cpumask *mask, int op)
+{
+ unsigned int cpu;
+
+ for_each_cpu(cpu, mask) {
+ send_IPI_single(cpu, op);
+ }
+}
+
+/*
+ * Called with preemption disabled.
+ */
+static inline void
+send_IPI_all (int op)
+{
+ int i;
+
+ for_each_online_cpu(i) {
+ send_IPI_single(i, op);
+ }
+}
+
+/*
+ * Called with preemption disabled.
+ */
+static inline void
+send_IPI_self (int op)
+{
+ send_IPI_single(smp_processor_id(), op);
+}
+
+#ifdef CONFIG_KEXEC
+void
+kdump_smp_send_stop(void)
+{
+ send_IPI_allbutself(IPI_KDUMP_CPU_STOP);
+}
+
+void
+kdump_smp_send_init(void)
+{
+ unsigned int cpu, self_cpu;
+ self_cpu = smp_processor_id();
+ for_each_online_cpu(cpu) {
+ if (cpu != self_cpu) {
+ if(kdump_status[cpu] == 0)
+ platform_send_ipi(cpu, 0, IA64_IPI_DM_INIT, 0);
+ }
+ }
+}
+#endif
+/*
+ * Called with preemption disabled.
+ */
+void
+smp_send_reschedule (int cpu)
+{
+ platform_send_ipi(cpu, IA64_IPI_RESCHEDULE, IA64_IPI_DM_INT, 0);
+}
+EXPORT_SYMBOL_GPL(smp_send_reschedule);
+
+/*
+ * Called with preemption disabled.
+ */
+static void
+smp_send_local_flush_tlb (int cpu)
+{
+ platform_send_ipi(cpu, IA64_IPI_LOCAL_TLB_FLUSH, IA64_IPI_DM_INT, 0);
+}
+
+void
+smp_local_flush_tlb(void)
+{
+ /*
+ * Use atomic ops. Otherwise, the load/increment/store sequence from
+ * a "++" operation can have the line stolen between the load & store.
+ * The overhead of the atomic op in negligible in this case & offers
+ * significant benefit for the brief periods where lots of cpus
+ * are simultaneously flushing TLBs.
+ */
+ ia64_fetchadd(1, &local_tlb_flush_counts[smp_processor_id()].count, acq);
+ local_flush_tlb_all();
+}
+
+#define FLUSH_DELAY 5 /* Usec backoff to eliminate excessive cacheline bouncing */
+
+void
+smp_flush_tlb_cpumask(cpumask_t xcpumask)
+{
+ unsigned short *counts = __ia64_per_cpu_var(shadow_flush_counts);
+ cpumask_t cpumask = xcpumask;
+ int mycpu, cpu, flush_mycpu = 0;
+
+ preempt_disable();
+ mycpu = smp_processor_id();
+
+ for_each_cpu(cpu, &cpumask)
+ counts[cpu] = local_tlb_flush_counts[cpu].count & 0xffff;
+
+ mb();
+ for_each_cpu(cpu, &cpumask) {
+ if (cpu == mycpu)
+ flush_mycpu = 1;
+ else
+ smp_send_local_flush_tlb(cpu);
+ }
+
+ if (flush_mycpu)
+ smp_local_flush_tlb();
+
+ for_each_cpu(cpu, &cpumask)
+ while(counts[cpu] == (local_tlb_flush_counts[cpu].count & 0xffff))
+ udelay(FLUSH_DELAY);
+
+ preempt_enable();
+}
+
+void
+smp_flush_tlb_all (void)
+{
+ on_each_cpu((void (*)(void *))local_flush_tlb_all, NULL, 1);
+}
+
+void
+smp_flush_tlb_mm (struct mm_struct *mm)
+{
+ cpumask_var_t cpus;
+ preempt_disable();
+ /* 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);
+ preempt_enable();
+ return;
+ }
+ if (!alloc_cpumask_var(&cpus, GFP_ATOMIC)) {
+ smp_call_function((void (*)(void *))local_finish_flush_tlb_mm,
+ mm, 1);
+ } else {
+ cpumask_copy(cpus, mm_cpumask(mm));
+ smp_call_function_many(cpus,
+ (void (*)(void *))local_finish_flush_tlb_mm, mm, 1);
+ free_cpumask_var(cpus);
+ }
+ local_irq_disable();
+ local_finish_flush_tlb_mm(mm);
+ local_irq_enable();
+ preempt_enable();
+}
+
+void arch_send_call_function_single_ipi(int cpu)
+{
+ send_IPI_single(cpu, IPI_CALL_FUNC_SINGLE);
+}
+
+void arch_send_call_function_ipi_mask(const struct cpumask *mask)
+{
+ send_IPI_mask(mask, IPI_CALL_FUNC);
+}
+
+/*
+ * 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
+setup_profiling_timer (unsigned int multiplier)
+{
+ return -EINVAL;
+}