Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 471 insertions, 0 deletions

diff --git a/kernel/arch/x86/kernel/irq.c b/kernel/arch/x86/kernel/irq.c
new file mode 100644
index 000000000..e5952c225
--- /dev/null
+++ b/kernel/arch/x86/kernel/irq.c
@@ -0,0 +1,471 @@
+/*
+ * Common interrupt code for 32 and 64 bit
+ */
+#include <linux/cpu.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
+#include <linux/of.h>
+#include <linux/seq_file.h>
+#include <linux/smp.h>
+#include <linux/ftrace.h>
+#include <linux/delay.h>
+#include <linux/export.h>
+
+#include <asm/apic.h>
+#include <asm/io_apic.h>
+#include <asm/irq.h>
+#include <asm/idle.h>
+#include <asm/mce.h>
+#include <asm/hw_irq.h>
+#include <asm/desc.h>
+
+#define CREATE_TRACE_POINTS
+#include <asm/trace/irq_vectors.h>
+
+atomic_t irq_err_count;
+
+/* Function pointer for generic interrupt vector handling */
+void (*x86_platform_ipi_callback)(void) = NULL;
+
+/*
+ * '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)
+{
+	if (printk_ratelimit())
+		pr_err("unexpected IRQ trap at vector %02x\n", irq);
+
+	/*
+	 * Currently unexpected vectors happen only on SMP and APIC.
+	 * We _must_ ack these because every local APIC has only N
+	 * irq slots per priority level, and a 'hanging, unacked' IRQ
+	 * holds up an irq slot - in excessive cases (when multiple
+	 * unexpected vectors occur) that might lock up the APIC
+	 * completely.
+	 * But only ack when the APIC is enabled -AK
+	 */
+	ack_APIC_irq();
+}
+
+#define irq_stats(x)		(&per_cpu(irq_stat, x))
+/*
+ * /proc/interrupts printing for arch specific interrupts
+ */
+int arch_show_interrupts(struct seq_file *p, int prec)
+{
+	int j;
+
+	seq_printf(p, "%*s: ", prec, "NMI");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ", irq_stats(j)->__nmi_count);
+	seq_puts(p, "  Non-maskable interrupts\n");
+#ifdef CONFIG_X86_LOCAL_APIC
+	seq_printf(p, "%*s: ", prec, "LOC");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ", irq_stats(j)->apic_timer_irqs);
+	seq_puts(p, "  Local timer interrupts\n");
+
+	seq_printf(p, "%*s: ", prec, "SPU");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ", irq_stats(j)->irq_spurious_count);
+	seq_puts(p, "  Spurious interrupts\n");
+	seq_printf(p, "%*s: ", prec, "PMI");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ", irq_stats(j)->apic_perf_irqs);
+	seq_puts(p, "  Performance monitoring interrupts\n");
+	seq_printf(p, "%*s: ", prec, "IWI");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ", irq_stats(j)->apic_irq_work_irqs);
+	seq_puts(p, "  IRQ work interrupts\n");
+	seq_printf(p, "%*s: ", prec, "RTR");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ", irq_stats(j)->icr_read_retry_count);
+	seq_puts(p, "  APIC ICR read retries\n");
+#endif
+	if (x86_platform_ipi_callback) {
+		seq_printf(p, "%*s: ", prec, "PLT");
+		for_each_online_cpu(j)
+			seq_printf(p, "%10u ", irq_stats(j)->x86_platform_ipis);
+		seq_puts(p, "  Platform interrupts\n");
+	}
+#ifdef CONFIG_SMP
+	seq_printf(p, "%*s: ", prec, "RES");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ", irq_stats(j)->irq_resched_count);
+	seq_puts(p, "  Rescheduling interrupts\n");
+	seq_printf(p, "%*s: ", prec, "CAL");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ", irq_stats(j)->irq_call_count -
+					irq_stats(j)->irq_tlb_count);
+	seq_puts(p, "  Function call interrupts\n");
+	seq_printf(p, "%*s: ", prec, "TLB");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ", irq_stats(j)->irq_tlb_count);
+	seq_puts(p, "  TLB shootdowns\n");
+#endif
+#ifdef CONFIG_X86_THERMAL_VECTOR
+	seq_printf(p, "%*s: ", prec, "TRM");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ", irq_stats(j)->irq_thermal_count);
+	seq_puts(p, "  Thermal event interrupts\n");
+#endif
+#ifdef CONFIG_X86_MCE_THRESHOLD
+	seq_printf(p, "%*s: ", prec, "THR");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ", irq_stats(j)->irq_threshold_count);
+	seq_puts(p, "  Threshold APIC interrupts\n");
+#endif
+#ifdef CONFIG_X86_MCE
+	seq_printf(p, "%*s: ", prec, "MCE");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ", per_cpu(mce_exception_count, j));
+	seq_puts(p, "  Machine check exceptions\n");
+	seq_printf(p, "%*s: ", prec, "MCP");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ", per_cpu(mce_poll_count, j));
+	seq_puts(p, "  Machine check polls\n");
+#endif
+#if IS_ENABLED(CONFIG_HYPERV) || defined(CONFIG_XEN)
+	seq_printf(p, "%*s: ", prec, "HYP");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ", irq_stats(j)->irq_hv_callback_count);
+	seq_puts(p, "  Hypervisor callback interrupts\n");
+#endif
+	seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
+#if defined(CONFIG_X86_IO_APIC)
+	seq_printf(p, "%*s: %10u\n", prec, "MIS", atomic_read(&irq_mis_count));
+#endif
+	return 0;
+}
+
+/*
+ * /proc/stat helpers
+ */
+u64 arch_irq_stat_cpu(unsigned int cpu)
+{
+	u64 sum = irq_stats(cpu)->__nmi_count;
+
+#ifdef CONFIG_X86_LOCAL_APIC
+	sum += irq_stats(cpu)->apic_timer_irqs;
+	sum += irq_stats(cpu)->irq_spurious_count;
+	sum += irq_stats(cpu)->apic_perf_irqs;
+	sum += irq_stats(cpu)->apic_irq_work_irqs;
+	sum += irq_stats(cpu)->icr_read_retry_count;
+#endif
+	if (x86_platform_ipi_callback)
+		sum += irq_stats(cpu)->x86_platform_ipis;
+#ifdef CONFIG_SMP
+	sum += irq_stats(cpu)->irq_resched_count;
+	sum += irq_stats(cpu)->irq_call_count;
+#endif
+#ifdef CONFIG_X86_THERMAL_VECTOR
+	sum += irq_stats(cpu)->irq_thermal_count;
+#endif
+#ifdef CONFIG_X86_MCE_THRESHOLD
+	sum += irq_stats(cpu)->irq_threshold_count;
+#endif
+#ifdef CONFIG_X86_MCE
+	sum += per_cpu(mce_exception_count, cpu);
+	sum += per_cpu(mce_poll_count, cpu);
+#endif
+	return sum;
+}
+
+u64 arch_irq_stat(void)
+{
+	u64 sum = atomic_read(&irq_err_count);
+	return sum;
+}
+
+
+/*
+ * do_IRQ handles all normal device IRQ's (the special
+ * SMP cross-CPU interrupts have their own specific
+ * handlers).
+ */
+__visible unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
+{
+	struct pt_regs *old_regs = set_irq_regs(regs);
+
+	/* high bit used in ret_from_ code  */
+	unsigned vector = ~regs->orig_ax;
+	unsigned irq;
+
+	irq_enter();
+	exit_idle();
+
+	irq = __this_cpu_read(vector_irq[vector]);
+
+	if (!handle_irq(irq, regs)) {
+		ack_APIC_irq();
+
+		if (irq != VECTOR_RETRIGGERED) {
+			pr_emerg_ratelimited("%s: %d.%d No irq handler for vector (irq %d)\n",
+					     __func__, smp_processor_id(),
+					     vector, irq);
+		} else {
+			__this_cpu_write(vector_irq[vector], VECTOR_UNDEFINED);
+		}
+	}
+
+	irq_exit();
+
+	set_irq_regs(old_regs);
+	return 1;
+}
+
+/*
+ * Handler for X86_PLATFORM_IPI_VECTOR.
+ */
+void __smp_x86_platform_ipi(void)
+{
+	inc_irq_stat(x86_platform_ipis);
+
+	if (x86_platform_ipi_callback)
+		x86_platform_ipi_callback();
+}
+
+__visible void smp_x86_platform_ipi(struct pt_regs *regs)
+{
+	struct pt_regs *old_regs = set_irq_regs(regs);
+
+	entering_ack_irq();
+	__smp_x86_platform_ipi();
+	exiting_irq();
+	set_irq_regs(old_regs);
+}
+
+#ifdef CONFIG_HAVE_KVM
+/*
+ * Handler for POSTED_INTERRUPT_VECTOR.
+ */
+__visible void smp_kvm_posted_intr_ipi(struct pt_regs *regs)
+{
+	struct pt_regs *old_regs = set_irq_regs(regs);
+
+	ack_APIC_irq();
+
+	irq_enter();
+
+	exit_idle();
+
+	inc_irq_stat(kvm_posted_intr_ipis);
+
+	irq_exit();
+
+	set_irq_regs(old_regs);
+}
+#endif
+
+__visible void smp_trace_x86_platform_ipi(struct pt_regs *regs)
+{
+	struct pt_regs *old_regs = set_irq_regs(regs);
+
+	entering_ack_irq();
+	trace_x86_platform_ipi_entry(X86_PLATFORM_IPI_VECTOR);
+	__smp_x86_platform_ipi();
+	trace_x86_platform_ipi_exit(X86_PLATFORM_IPI_VECTOR);
+	exiting_irq();
+	set_irq_regs(old_regs);
+}
+
+EXPORT_SYMBOL_GPL(vector_used_by_percpu_irq);
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+/* These two declarations are only used in check_irq_vectors_for_cpu_disable()
+ * below, which is protected by stop_machine().  Putting them on the stack
+ * results in a stack frame overflow.  Dynamically allocating could result in a
+ * failure so declare these two cpumasks as global.
+ */
+static struct cpumask affinity_new, online_new;
+
+/*
+ * This cpu is going to be removed and its vectors migrated to the remaining
+ * online cpus.  Check to see if there are enough vectors in the remaining cpus.
+ * This function is protected by stop_machine().
+ */
+int check_irq_vectors_for_cpu_disable(void)
+{
+	int irq, cpu;
+	unsigned int this_cpu, vector, this_count, count;
+	struct irq_desc *desc;
+	struct irq_data *data;
+
+	this_cpu = smp_processor_id();
+	cpumask_copy(&online_new, cpu_online_mask);
+	cpumask_clear_cpu(this_cpu, &online_new);
+
+	this_count = 0;
+	for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
+		irq = __this_cpu_read(vector_irq[vector]);
+		if (irq >= 0) {
+			desc = irq_to_desc(irq);
+			if (!desc)
+				continue;
+
+			data = irq_desc_get_irq_data(desc);
+			cpumask_copy(&affinity_new, data->affinity);
+			cpumask_clear_cpu(this_cpu, &affinity_new);
+
+			/* Do not count inactive or per-cpu irqs. */
+			if (!irq_has_action(irq) || irqd_is_per_cpu(data))
+				continue;
+
+			/*
+			 * A single irq may be mapped to multiple
+			 * cpu's vector_irq[] (for example IOAPIC cluster
+			 * mode).  In this case we have two
+			 * possibilities:
+			 *
+			 * 1) the resulting affinity mask is empty; that is
+			 * this the down'd cpu is the last cpu in the irq's
+			 * affinity mask, or
+			 *
+			 * 2) the resulting affinity mask is no longer
+			 * a subset of the online cpus but the affinity
+			 * mask is not zero; that is the down'd cpu is the
+			 * last online cpu in a user set affinity mask.
+			 */
+			if (cpumask_empty(&affinity_new) ||
+			    !cpumask_subset(&affinity_new, &online_new))
+				this_count++;
+		}
+	}
+
+	count = 0;
+	for_each_online_cpu(cpu) {
+		if (cpu == this_cpu)
+			continue;
+		/*
+		 * We scan from FIRST_EXTERNAL_VECTOR to first system
+		 * vector. If the vector is marked in the used vectors
+		 * bitmap or an irq is assigned to it, we don't count
+		 * it as available.
+		 */
+		for (vector = FIRST_EXTERNAL_VECTOR;
+		     vector < first_system_vector; vector++) {
+			if (!test_bit(vector, used_vectors) &&
+			    per_cpu(vector_irq, cpu)[vector] < 0)
+					count++;
+		}
+	}
+
+	if (count < this_count) {
+		pr_warn("CPU %d disable failed: CPU has %u vectors assigned and there are only %u available.\n",
+			this_cpu, this_count, count);
+		return -ERANGE;
+	}
+	return 0;
+}
+
+/* A cpu has been removed from cpu_online_mask.  Reset irq affinities. */
+void fixup_irqs(void)
+{
+	unsigned int irq, vector;
+	static int warned;
+	struct irq_desc *desc;
+	struct irq_data *data;
+	struct irq_chip *chip;
+	int ret;
+
+	for_each_irq_desc(irq, desc) {
+		int break_affinity = 0;
+		int set_affinity = 1;
+		const struct cpumask *affinity;
+
+		if (!desc)
+			continue;
+		if (irq == 2)
+			continue;
+
+		/* interrupt's are disabled at this point */
+		raw_spin_lock(&desc->lock);
+
+		data = irq_desc_get_irq_data(desc);
+		affinity = data->affinity;
+		if (!irq_has_action(irq) || irqd_is_per_cpu(data) ||
+		    cpumask_subset(affinity, cpu_online_mask)) {
+			raw_spin_unlock(&desc->lock);
+			continue;
+		}
+
+		/*
+		 * Complete the irq move. This cpu is going down and for
+		 * non intr-remapping case, we can't wait till this interrupt
+		 * arrives at this cpu before completing the irq move.
+		 */
+		irq_force_complete_move(irq);
+
+		if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
+			break_affinity = 1;
+			affinity = cpu_online_mask;
+		}
+
+		chip = irq_data_get_irq_chip(data);
+		if (!irqd_can_move_in_process_context(data) && chip->irq_mask)
+			chip->irq_mask(data);
+
+		if (chip->irq_set_affinity) {
+			ret = chip->irq_set_affinity(data, affinity, true);
+			if (ret == -ENOSPC)
+				pr_crit("IRQ %d set affinity failed because there are no available vectors.  The device assigned to this IRQ is unstable.\n", irq);
+		} else {
+			if (!(warned++))
+				set_affinity = 0;
+		}
+
+		/*
+		 * We unmask if the irq was not marked masked by the
+		 * core code. That respects the lazy irq disable
+		 * behaviour.
+		 */
+		if (!irqd_can_move_in_process_context(data) &&
+		    !irqd_irq_masked(data) && chip->irq_unmask)
+			chip->irq_unmask(data);
+
+		raw_spin_unlock(&desc->lock);
+
+		if (break_affinity && set_affinity)
+			pr_notice("Broke affinity for irq %i\n", irq);
+		else if (!set_affinity)
+			pr_notice("Cannot set affinity for irq %i\n", irq);
+	}
+
+	/*
+	 * We can remove mdelay() and then send spuriuous interrupts to
+	 * new cpu targets for all the irqs that were handled previously by
+	 * this cpu. While it works, I have seen spurious interrupt messages
+	 * (nothing wrong but still...).
+	 *
+	 * So for now, retain mdelay(1) and check the IRR and then send those
+	 * interrupts to new targets as this cpu is already offlined...
+	 */
+	mdelay(1);
+
+	for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
+		unsigned int irr;
+
+		if (__this_cpu_read(vector_irq[vector]) <= VECTOR_UNDEFINED)
+			continue;
+
+		irr = apic_read(APIC_IRR + (vector / 32 * 0x10));
+		if (irr  & (1 << (vector % 32))) {
+			irq = __this_cpu_read(vector_irq[vector]);
+
+			desc = irq_to_desc(irq);
+			data = irq_desc_get_irq_data(desc);
+			chip = irq_data_get_irq_chip(data);
+			raw_spin_lock(&desc->lock);
+			if (chip->irq_retrigger) {
+				chip->irq_retrigger(data);
+				__this_cpu_write(vector_irq[vector], VECTOR_RETRIGGERED);
+			}
+			raw_spin_unlock(&desc->lock);
+		}
+		if (__this_cpu_read(vector_irq[vector]) != VECTOR_RETRIGGERED)
+			__this_cpu_write(vector_irq[vector], VECTOR_UNDEFINED);
+	}
+}
+#endif