1 /* 2 * Copyright (C) 2011-12 Synopsys, Inc. (www.synopsys.com) 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 * 8 */ 9 10 #include <linux/interrupt.h> 11 #include <linux/irqchip.h> 12 #include <asm/mach_desc.h> 13 #include <asm/smp.h> 14 15 /* 16 * Late Interrupt system init called from start_kernel for Boot CPU only 17 * 18 * Since slab must already be initialized, platforms can start doing any 19 * needed request_irq( )s 20 */ 21 void __init init_IRQ(void) 22 { 23 /* 24 * process the entire interrupt tree in one go 25 * Any external intc will be setup provided DT chains them 26 * properly 27 */ 28 irqchip_init(); 29 30 #ifdef CONFIG_SMP 31 /* a SMP H/w block could do IPI IRQ request here */ 32 if (plat_smp_ops.init_per_cpu) 33 plat_smp_ops.init_per_cpu(smp_processor_id()); 34 35 if (machine_desc->init_per_cpu) 36 machine_desc->init_per_cpu(smp_processor_id()); 37 #endif 38 } 39 40 /* 41 * "C" Entry point for any ARC ISR, called from low level vector handler 42 * @irq is the vector number read from ICAUSE reg of on-chip intc 43 */ 44 void arch_do_IRQ(unsigned int irq, struct pt_regs *regs) 45 { 46 struct pt_regs *old_regs = set_irq_regs(regs); 47 48 irq_enter(); 49 generic_handle_irq(irq); 50 irq_exit(); 51 set_irq_regs(old_regs); 52 } 53 54 /* 55 * API called for requesting percpu interrupts - called by each CPU 56 * - For boot CPU, actually request the IRQ with genirq core + enables 57 * - For subsequent callers only enable called locally 58 * 59 * Relies on being called by boot cpu first (i.e. request called ahead) of 60 * any enable as expected by genirq. Hence Suitable only for TIMER, IPI 61 * which are guaranteed to be setup on boot core first. 62 * Late probed peripherals such as perf can't use this as there no guarantee 63 * of being called on boot CPU first. 64 */ 65 66 void arc_request_percpu_irq(int irq, int cpu, 67 irqreturn_t (*isr)(int irq, void *dev), 68 const char *irq_nm, 69 void *percpu_dev) 70 { 71 /* Boot cpu calls request, all call enable */ 72 if (!cpu) { 73 int rc; 74 75 #ifdef CONFIG_ISA_ARCOMPACT 76 /* 77 * A subsequent request_percpu_irq() fails if percpu_devid is 78 * not set. That in turns sets NOAUTOEN, meaning each core needs 79 * to call enable_percpu_irq() 80 * 81 * For ARCv2, this is done in irq map function since we know 82 * which irqs are strictly per cpu 83 */ 84 irq_set_percpu_devid(irq); 85 #endif 86 87 rc = request_percpu_irq(irq, isr, irq_nm, percpu_dev); 88 if (rc) 89 panic("Percpu IRQ request failed for %d\n", irq); 90 } 91 92 enable_percpu_irq(irq, 0); 93 } 94