Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 195 insertions, 0 deletions

diff --git a/arch/arc/kernel/intc-arcv2.c b/arch/arc/kernel/intc-arcv2.c
new file mode 100644
index 000000000..cf18b3e5a
--- /dev/null
+++ b/arch/arc/kernel/intc-arcv2.c
@@ -0,0 +1,195 @@
+/*
+ * 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;
+
+#ifndef CONFIG_ARC_IRQ_NO_AUTOSAVE
+	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 */
+#endif
+
+	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);