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 */
21void __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 */
44void 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
66void 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}