v4.19.13 snapshot.
diff --git a/arch/ia64/kernel/irq.c b/arch/ia64/kernel/irq.c
new file mode 100644
index 0000000..8ed81b2
--- /dev/null
+++ b/arch/ia64/kernel/irq.c
@@ -0,0 +1,203 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/arch/ia64/kernel/irq.c
+ *
+ * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
+ *
+ * This file contains the code used by various IRQ handling routines:
+ * asking for different IRQs should be done through these routines
+ * instead of just grabbing them. Thus setups with different IRQ numbers
+ * shouldn't result in any weird surprises, and installing new handlers
+ * should be easier.
+ *
+ * Copyright (C) Ashok Raj<ashok.raj@intel.com>, Intel Corporation 2004
+ *
+ * 4/14/2004: Added code to handle cpu migration and do safe irq
+ * migration without losing interrupts for iosapic
+ * architecture.
+ */
+
+#include <asm/delay.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/seq_file.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
+
+#include <asm/mca.h>
+
+/*
+ * 'what should we do if we get a hw irq event on an illegal vector'.
+ * each architecture has to answer this themselves.
+ */
+void ack_bad_irq(unsigned int irq)
+{
+ printk(KERN_ERR "Unexpected irq vector 0x%x on CPU %u!\n", irq, smp_processor_id());
+}
+
+#ifdef CONFIG_IA64_GENERIC
+ia64_vector __ia64_irq_to_vector(int irq)
+{
+ return irq_cfg[irq].vector;
+}
+
+unsigned int __ia64_local_vector_to_irq (ia64_vector vec)
+{
+ return __this_cpu_read(vector_irq[vec]);
+}
+#endif
+
+/*
+ * Interrupt statistics:
+ */
+
+atomic_t irq_err_count;
+
+/*
+ * /proc/interrupts printing:
+ */
+int arch_show_interrupts(struct seq_file *p, int prec)
+{
+ seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
+ return 0;
+}
+
+#ifdef CONFIG_SMP
+static char irq_redir [NR_IRQS]; // = { [0 ... NR_IRQS-1] = 1 };
+
+void set_irq_affinity_info (unsigned int irq, int hwid, int redir)
+{
+ if (irq < NR_IRQS) {
+ cpumask_copy(irq_get_affinity_mask(irq),
+ cpumask_of(cpu_logical_id(hwid)));
+ irq_redir[irq] = (char) (redir & 0xff);
+ }
+}
+
+bool is_affinity_mask_valid(const struct cpumask *cpumask)
+{
+ if (ia64_platform_is("sn2")) {
+ /* Only allow one CPU to be specified in the smp_affinity mask */
+ if (cpumask_weight(cpumask) != 1)
+ return false;
+ }
+ return true;
+}
+
+#endif /* CONFIG_SMP */
+
+int __init arch_early_irq_init(void)
+{
+ ia64_mca_irq_init();
+ return 0;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+unsigned int vectors_in_migration[NR_IRQS];
+
+/*
+ * Since cpu_online_mask is already updated, we just need to check for
+ * affinity that has zeros
+ */
+static void migrate_irqs(void)
+{
+ int irq, new_cpu;
+
+ for (irq=0; irq < NR_IRQS; irq++) {
+ struct irq_desc *desc = irq_to_desc(irq);
+ struct irq_data *data = irq_desc_get_irq_data(desc);
+ struct irq_chip *chip = irq_data_get_irq_chip(data);
+
+ if (irqd_irq_disabled(data))
+ continue;
+
+ /*
+ * No handling for now.
+ * TBD: Implement a disable function so we can now
+ * tell CPU not to respond to these local intr sources.
+ * such as ITV,CPEI,MCA etc.
+ */
+ if (irqd_is_per_cpu(data))
+ continue;
+
+ if (cpumask_any_and(irq_data_get_affinity_mask(data),
+ cpu_online_mask) >= nr_cpu_ids) {
+ /*
+ * Save it for phase 2 processing
+ */
+ vectors_in_migration[irq] = irq;
+
+ new_cpu = cpumask_any(cpu_online_mask);
+
+ /*
+ * Al three are essential, currently WARN_ON.. maybe panic?
+ */
+ if (chip && chip->irq_disable &&
+ chip->irq_enable && chip->irq_set_affinity) {
+ chip->irq_disable(data);
+ chip->irq_set_affinity(data,
+ cpumask_of(new_cpu), false);
+ chip->irq_enable(data);
+ } else {
+ WARN_ON((!chip || !chip->irq_disable ||
+ !chip->irq_enable ||
+ !chip->irq_set_affinity));
+ }
+ }
+ }
+}
+
+void fixup_irqs(void)
+{
+ unsigned int irq;
+ extern void ia64_process_pending_intr(void);
+ extern volatile int time_keeper_id;
+
+ /* Mask ITV to disable timer */
+ ia64_set_itv(1 << 16);
+
+ /*
+ * Find a new timesync master
+ */
+ if (smp_processor_id() == time_keeper_id) {
+ time_keeper_id = cpumask_first(cpu_online_mask);
+ printk ("CPU %d is now promoted to time-keeper master\n", time_keeper_id);
+ }
+
+ /*
+ * Phase 1: Locate IRQs bound to this cpu and
+ * relocate them for cpu removal.
+ */
+ migrate_irqs();
+
+ /*
+ * Phase 2: Perform interrupt processing for all entries reported in
+ * local APIC.
+ */
+ ia64_process_pending_intr();
+
+ /*
+ * Phase 3: Now handle any interrupts not captured in local APIC.
+ * This is to account for cases that device interrupted during the time the
+ * rte was being disabled and re-programmed.
+ */
+ for (irq=0; irq < NR_IRQS; irq++) {
+ if (vectors_in_migration[irq]) {
+ struct pt_regs *old_regs = set_irq_regs(NULL);
+
+ vectors_in_migration[irq]=0;
+ generic_handle_irq(irq);
+ set_irq_regs(old_regs);
+ }
+ }
+
+ /*
+ * Now let processor die. We do irq disable and max_xtp() to
+ * ensure there is no more interrupts routed to this processor.
+ * But the local timer interrupt can have 1 pending which we
+ * take care in timer_interrupt().
+ */
+ max_xtp();
+ local_irq_disable();
+}
+#endif