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