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Release 4.14 arch/arc/kernel/intc-compact.c

Directory: arch/arc/kernel
/*
 * Copyright (C) 2011-12 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_CPU_IRQS	32	
/* number of irq lines coming in */

#define TIMER0_IRQ	3	
/* Fixed by ISA */

/*
 * Early Hardware specific Interrupt setup
 * -Platform independent, needed for each CPU (not foldable into init_IRQ)
 * -Called very early (start_kernel -> setup_arch -> setup_processor)
 *
 * what it does ?
 * -Optionally, setup the High priority Interrupts as Level 2 IRQs
 */

void arc_init_IRQ(void) { unsigned int level_mask = 0, i; /* Is timer high priority Interrupt (Level2 in ARCompact jargon) */ level_mask |= IS_ENABLED(CONFIG_ARC_COMPACT_IRQ_LEVELS) << TIMER0_IRQ; /* * Write to register, even if no LV2 IRQs configured to reset it * in case bootloader had mucked with it */ write_aux_reg(AUX_IRQ_LEV, level_mask); if (level_mask) pr_info("Level-2 interrupts bitset %x\n", level_mask); /* * Disable all IRQ lines so faulty external hardware won't * trigger interrupt that kernel is not ready to handle. */ for (i = TIMER0_IRQ; i < NR_CPU_IRQS; i++) { unsigned int ienb; ienb = read_aux_reg(AUX_IENABLE); ienb &= ~(1 << i); write_aux_reg(AUX_IENABLE, ienb); } }

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Alexey Brodkin4652.87%250.00%
Vineet Gupta4147.13%250.00%
Total87100.00%4100.00%

/* * ARC700 core includes a simple on-chip intc supporting * -per IRQ enable/disable * -2 levels of interrupts (high/low) * -all interrupts being level triggered * * To reduce platform code, we assume all IRQs directly hooked-up into intc. * Platforms with external intc, hence cascaded IRQs, are free to over-ride * below, per IRQ. */
static void arc_irq_mask(struct irq_data *data) { unsigned int ienb; ienb = read_aux_reg(AUX_IENABLE); ienb &= ~(1 << data->hwirq); write_aux_reg(AUX_IENABLE, ienb); }

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Vineet Gupta3997.50%150.00%
Yuriy Kolerov12.50%150.00%
Total40100.00%2100.00%


static void arc_irq_unmask(struct irq_data *data) { unsigned int ienb; ienb = read_aux_reg(AUX_IENABLE); ienb |= (1 << data->hwirq); write_aux_reg(AUX_IENABLE, ienb); }

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Vineet Gupta3897.44%150.00%
Yuriy Kolerov12.56%150.00%
Total39100.00%2100.00%

static struct irq_chip onchip_intc = { .name = "ARC In-core Intc", .irq_mask = arc_irq_mask, .irq_unmask = arc_irq_unmask, };
static int arc_intc_domain_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw) { switch (hw) { case TIMER0_IRQ: irq_set_percpu_devid(irq); irq_set_chip_and_handler(irq, &onchip_intc, handle_percpu_irq); break; default: irq_set_chip_and_handler(irq, &onchip_intc, handle_level_irq); } return 0; }

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Vineet Gupta57100.00%3100.00%
Total57100.00%3100.00%

static const struct irq_domain_ops arc_intc_domain_ops = { .xlate = irq_domain_xlate_onecell, .map = arc_intc_domain_map, };
static int __init init_onchip_IRQ(struct device_node *intc, struct device_node *parent) { struct irq_domain *root_domain; if (parent) panic("DeviceTree incore intc not a root irq controller\n"); root_domain = irq_domain_add_linear(intc, NR_CPU_IRQS, &arc_intc_domain_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); return 0; }

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Vineet Gupta64100.00%3100.00%
Total64100.00%3100.00%

IRQCHIP_DECLARE(arc_intc, "snps,arc700-intc", init_onchip_IRQ); /* * arch_local_irq_enable - Enable interrupts. * * 1. Explicitly called to re-enable interrupts * 2. Implicitly called from spin_unlock_irq, write_unlock_irq etc * which maybe in hard ISR itself * * Semantics of this function change depending on where it is called from: * * -If called from hard-ISR, it must not invert interrupt priorities * e.g. suppose TIMER is high priority (Level 2) IRQ * Time hard-ISR, timer_interrupt( ) calls spin_unlock_irq several times. * Here local_irq_enable( ) shd not re-enable lower priority interrupts * -If called from soft-ISR, it must re-enable all interrupts * soft ISR are low prioity jobs which can be very slow, thus all IRQs * must be enabled while they run. * Now hardware context wise we may still be in L2 ISR (not done rtie) * still we must re-enable both L1 and L2 IRQs * Another twist is prev scenario with flow being * L1 ISR ==> interrupted by L2 ISR ==> L2 soft ISR * here we must not re-enable Ll as prev Ll Interrupt's h/w context will get * over-written (this is deficiency in ARC700 Interrupt mechanism) */ #ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS /* Complex version for 2 IRQ levels */
void arch_local_irq_enable(void) { unsigned long flags = arch_local_save_flags(); if (flags & STATUS_A2_MASK) flags |= STATUS_E2_MASK; else if (flags & STATUS_A1_MASK) flags |= STATUS_E1_MASK; arch_local_irq_restore(flags); }

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Vineet Gupta40100.00%2100.00%
Total40100.00%2100.00%

EXPORT_SYMBOL(arch_local_irq_enable); #endif

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PersonTokensPropCommitsCommitProp
Vineet Gupta37188.54%975.00%
Alexey Brodkin4610.98%216.67%
Yuriy Kolerov20.48%18.33%
Total419100.00%12100.00%
Directory: arch/arc/kernel
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