diff options
Diffstat (limited to 'kernel/arch/arc/kernel/intc-arcv2.c')
| -rw-r--r-- | kernel/arch/arc/kernel/intc-arcv2.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/kernel/arch/arc/kernel/intc-arcv2.c b/kernel/arch/arc/kernel/intc-arcv2.c new file mode 100644 index 000000000..0394f9f61 --- /dev/null +++ b/kernel/arch/arc/kernel/intc-arcv2.c @@ -0,0 +1,153 @@ +/* + * 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> + +/* + * 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; + + 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); + + /* setup status32, don't enable intr yet as kernel doesn't want */ + tmp = read_aux_reg(0xa); + tmp |= ISA_INIT_STATUS_BITS; + tmp &= ~STATUS_IE_MASK; + asm volatile("flag %0 \n"::"r"(tmp)); + + /* + * 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 the intc BCR to confirm that Linux default priority is avail + * in h/w + * + * Note: + * IRQ_BCR[27..24] contains N-1 (for N priority levels) and prio level + * is 0 based. + */ + tmp = (read_aux_reg(ARC_REG_IRQ_BCR) >> 24 ) & 0xF; + if (ARCV2_IRQ_DEF_PRIO > tmp) + panic("Linux default irq prio incorrect\n"); +} + +static void arcv2_irq_mask(struct irq_data *data) +{ + write_aux_reg(AUX_IRQ_SELECT, data->irq); + write_aux_reg(AUX_IRQ_ENABLE, 0); +} + +static void arcv2_irq_unmask(struct irq_data *data) +{ + write_aux_reg(AUX_IRQ_SELECT, data->irq); + 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->irq); + 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 < 24) { + /* + * 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 struct irq_domain *root_domain; + +static int __init +init_onchip_IRQ(struct device_node *intc, struct device_node *parent) +{ + if (parent) + panic("DeviceTree incore intc not a root irq controller\n"); + + root_domain = irq_domain_add_legacy(intc, NR_CPU_IRQS, 0, 0, + &arcv2_irq_ops, NULL); + + if (!root_domain) + panic("root irq domain not avail\n"); + + /* with this we don't need to export root_domain */ + irq_set_default_host(root_domain); + + return 0; +} + +IRQCHIP_DECLARE(arc_intc, "snps,archs-intc", init_onchip_IRQ); |