v4.19.13 snapshot.
diff --git a/arch/arc/kernel/intc-arcv2.c b/arch/arc/kernel/intc-arcv2.c
new file mode 100644
index 0000000..067ea36
--- /dev/null
+++ b/arch/arc/kernel/intc-arcv2.c
@@ -0,0 +1,193 @@
+/*
+ * Copyright (C) 2014 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/irqdomain.h>
+#include <linux/irqchip.h>
+#include <asm/irq.h>
+
+#define NR_EXCEPTIONS 16
+
+struct bcr_irq_arcv2 {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+ unsigned int pad:3, firq:1, prio:4, exts:8, irqs:8, ver:8;
+#else
+ unsigned int ver:8, irqs:8, exts:8, prio:4, firq:1, pad:3;
+#endif
+};
+
+/*
+ * Early Hardware specific Interrupt setup
+ * -Called very early (start_kernel -> setup_arch -> setup_processor)
+ * -Platform Independent (must for any ARC Core)
+ * -Needed for each CPU (hence not foldable into init_IRQ)
+ */
+void arc_init_IRQ(void)
+{
+ unsigned int tmp, irq_prio, i;
+ struct bcr_irq_arcv2 irq_bcr;
+
+ struct aux_irq_ctrl {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+ unsigned int res3:18, save_idx_regs:1, res2:1,
+ save_u_to_u:1, save_lp_regs:1, save_blink:1,
+ res:4, save_nr_gpr_pairs:5;
+#else
+ unsigned int save_nr_gpr_pairs:5, res:4,
+ save_blink:1, save_lp_regs:1, save_u_to_u:1,
+ res2:1, save_idx_regs:1, res3:18;
+#endif
+ } ictrl;
+
+ *(unsigned int *)&ictrl = 0;
+
+ ictrl.save_nr_gpr_pairs = 6; /* r0 to r11 (r12 saved manually) */
+ ictrl.save_blink = 1;
+ ictrl.save_lp_regs = 1; /* LP_COUNT, LP_START, LP_END */
+ ictrl.save_u_to_u = 0; /* user ctxt saved on kernel stack */
+ ictrl.save_idx_regs = 1; /* JLI, LDI, EI */
+
+ WRITE_AUX(AUX_IRQ_CTRL, ictrl);
+
+ /*
+ * ARCv2 core intc provides multiple interrupt priorities (upto 16).
+ * Typical builds though have only two levels (0-high, 1-low)
+ * Linux by default uses lower prio 1 for most irqs, reserving 0 for
+ * NMI style interrupts in future (say perf)
+ */
+
+ READ_BCR(ARC_REG_IRQ_BCR, irq_bcr);
+
+ irq_prio = irq_bcr.prio; /* Encoded as N-1 for N levels */
+ pr_info("archs-intc\t: %d priority levels (default %d)%s\n",
+ irq_prio + 1, ARCV2_IRQ_DEF_PRIO,
+ irq_bcr.firq ? " FIRQ (not used)":"");
+
+ /*
+ * Set a default priority for all available interrupts to prevent
+ * switching of register banks if Fast IRQ and multiple register banks
+ * are supported by CPU.
+ * Also disable private-per-core IRQ lines so faulty external HW won't
+ * trigger interrupt that kernel is not ready to handle.
+ */
+ for (i = NR_EXCEPTIONS; i < irq_bcr.irqs + NR_EXCEPTIONS; i++) {
+ write_aux_reg(AUX_IRQ_SELECT, i);
+ write_aux_reg(AUX_IRQ_PRIORITY, ARCV2_IRQ_DEF_PRIO);
+
+ /*
+ * Only mask cpu private IRQs here.
+ * "common" interrupts are masked at IDU, otherwise it would
+ * need to be unmasked at each cpu, with IPIs
+ */
+ if (i < FIRST_EXT_IRQ)
+ write_aux_reg(AUX_IRQ_ENABLE, 0);
+ }
+
+ /* setup status32, don't enable intr yet as kernel doesn't want */
+ tmp = read_aux_reg(ARC_REG_STATUS32);
+ tmp |= STATUS_AD_MASK | (ARCV2_IRQ_DEF_PRIO << 1);
+ tmp &= ~STATUS_IE_MASK;
+ asm volatile("kflag %0 \n"::"r"(tmp));
+}
+
+static void arcv2_irq_mask(struct irq_data *data)
+{
+ write_aux_reg(AUX_IRQ_SELECT, data->hwirq);
+ write_aux_reg(AUX_IRQ_ENABLE, 0);
+}
+
+static void arcv2_irq_unmask(struct irq_data *data)
+{
+ write_aux_reg(AUX_IRQ_SELECT, data->hwirq);
+ write_aux_reg(AUX_IRQ_ENABLE, 1);
+}
+
+void arcv2_irq_enable(struct irq_data *data)
+{
+ /* set default priority */
+ write_aux_reg(AUX_IRQ_SELECT, data->hwirq);
+ write_aux_reg(AUX_IRQ_PRIORITY, ARCV2_IRQ_DEF_PRIO);
+
+ /*
+ * hw auto enables (linux unmask) all by default
+ * So no need to do IRQ_ENABLE here
+ * XXX: However OSCI LAN need it
+ */
+ write_aux_reg(AUX_IRQ_ENABLE, 1);
+}
+
+static struct irq_chip arcv2_irq_chip = {
+ .name = "ARCv2 core Intc",
+ .irq_mask = arcv2_irq_mask,
+ .irq_unmask = arcv2_irq_unmask,
+ .irq_enable = arcv2_irq_enable
+};
+
+static int arcv2_irq_map(struct irq_domain *d, unsigned int irq,
+ irq_hw_number_t hw)
+{
+ /*
+ * core intc IRQs [16, 23]:
+ * Statically assigned always private-per-core (Timers, WDT, IPI, PCT)
+ */
+ if (hw < FIRST_EXT_IRQ) {
+ /*
+ * A subsequent request_percpu_irq() fails if percpu_devid is
+ * not set. That in turns sets NOAUTOEN, meaning each core needs
+ * to call enable_percpu_irq()
+ */
+ irq_set_percpu_devid(irq);
+ irq_set_chip_and_handler(irq, &arcv2_irq_chip, handle_percpu_irq);
+ } else {
+ irq_set_chip_and_handler(irq, &arcv2_irq_chip, handle_level_irq);
+ }
+
+ return 0;
+}
+
+static const struct irq_domain_ops arcv2_irq_ops = {
+ .xlate = irq_domain_xlate_onecell,
+ .map = arcv2_irq_map,
+};
+
+
+static int __init
+init_onchip_IRQ(struct device_node *intc, struct device_node *parent)
+{
+ struct irq_domain *root_domain;
+ struct bcr_irq_arcv2 irq_bcr;
+ unsigned int nr_cpu_irqs;
+
+ READ_BCR(ARC_REG_IRQ_BCR, irq_bcr);
+ nr_cpu_irqs = irq_bcr.irqs + NR_EXCEPTIONS;
+
+ if (parent)
+ panic("DeviceTree incore intc not a root irq controller\n");
+
+ root_domain = irq_domain_add_linear(intc, nr_cpu_irqs, &arcv2_irq_ops, NULL);
+ if (!root_domain)
+ panic("root irq domain not avail\n");
+
+ /*
+ * Needed for primary domain lookup to succeed
+ * This is a primary irqchip, and can never have a parent
+ */
+ irq_set_default_host(root_domain);
+
+#ifdef CONFIG_SMP
+ irq_create_mapping(root_domain, IPI_IRQ);
+#endif
+ irq_create_mapping(root_domain, SOFTIRQ_IRQ);
+
+ return 0;
+}
+
+IRQCHIP_DECLARE(arc_intc, "snps,archs-intc", init_onchip_IRQ);