Blame view

kernel/linux-rt-4.4.41/arch/mips/loongson64/lemote-2f/irq.c 3.22 KB
5113f6f70   김현기   kernel add
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
  /*
   * Copyright (C) 2007 Lemote Inc.
   * Author: Fuxin Zhang, zhangfx@lemote.com
   *
   *  This program is free software; you can redistribute	 it and/or modify it
   *  under  the terms of	 the GNU General  Public License as published by the
   *  Free Software Foundation;  either version 2 of the	License, or (at your
   *  option) any later version.
   */
  
  #include <linux/interrupt.h>
  #include <linux/module.h>
  
  #include <asm/irq_cpu.h>
  #include <asm/i8259.h>
  #include <asm/mipsregs.h>
  
  #include <loongson.h>
  #include <machine.h>
  
  #define LOONGSON_TIMER_IRQ	(MIPS_CPU_IRQ_BASE + 7) /* cpu timer */
  #define LOONGSON_NORTH_BRIDGE_IRQ	(MIPS_CPU_IRQ_BASE + 6) /* bonito */
  #define LOONGSON_UART_IRQ	(MIPS_CPU_IRQ_BASE + 3) /* cpu serial port */
  #define LOONGSON_SOUTH_BRIDGE_IRQ	(MIPS_CPU_IRQ_BASE + 2) /* i8259 */
  
  #define LOONGSON_INT_BIT_INT0		(1 << 11)
  #define LOONGSON_INT_BIT_INT1		(1 << 12)
  
  /*
   * The generic i8259_irq() make the kernel hang on booting.  Since we cannot
   * get the irq via the IRR directly, we access the ISR instead.
   */
  int mach_i8259_irq(void)
  {
  	int irq, isr;
  
  	irq = -1;
  
  	if ((LOONGSON_INTISR & LOONGSON_INTEN) & LOONGSON_INT_BIT_INT0) {
  		raw_spin_lock(&i8259A_lock);
  		isr = inb(PIC_MASTER_CMD) &
  			~inb(PIC_MASTER_IMR) & ~(1 << PIC_CASCADE_IR);
  		if (!isr)
  			isr = (inb(PIC_SLAVE_CMD) & ~inb(PIC_SLAVE_IMR)) << 8;
  		irq = ffs(isr) - 1;
  		if (unlikely(irq == 7)) {
  			/*
  			 * This may be a spurious interrupt.
  			 *
  			 * Read the interrupt status register (ISR). If the most
  			 * significant bit is not set then there is no valid
  			 * interrupt.
  			 */
  			outb(0x0B, PIC_MASTER_ISR);	/* ISR register */
  			if (~inb(PIC_MASTER_ISR) & 0x80)
  				irq = -1;
  		}
  		raw_spin_unlock(&i8259A_lock);
  	}
  
  	return irq;
  }
  EXPORT_SYMBOL(mach_i8259_irq);
  
  static void i8259_irqdispatch(void)
  {
  	int irq;
  
  	irq = mach_i8259_irq();
  	if (irq >= 0)
  		do_IRQ(irq);
  	else
  		spurious_interrupt();
  }
  
  void mach_irq_dispatch(unsigned int pending)
  {
  	if (pending & CAUSEF_IP7)
  		do_IRQ(LOONGSON_TIMER_IRQ);
  	else if (pending & CAUSEF_IP6) {	/* North Bridge, Perf counter */
  		do_perfcnt_IRQ();
  		bonito_irqdispatch();
  	} else if (pending & CAUSEF_IP3)	/* CPU UART */
  		do_IRQ(LOONGSON_UART_IRQ);
  	else if (pending & CAUSEF_IP2)	/* South Bridge */
  		i8259_irqdispatch();
  	else
  		spurious_interrupt();
  }
  
  static irqreturn_t ip6_action(int cpl, void *dev_id)
  {
  	return IRQ_HANDLED;
  }
  
  static struct irqaction ip6_irqaction = {
  	.handler = ip6_action,
  	.name = "cascade",
  	.flags = IRQF_SHARED | IRQF_NO_THREAD,
  };
  
  static struct irqaction cascade_irqaction = {
  	.handler = no_action,
  	.name = "cascade",
  	.flags = IRQF_NO_THREAD,
  };
  
  void __init mach_init_irq(void)
  {
  	/* init all controller
  	 *   0-15	  ------> i8259 interrupt
  	 *   16-23	  ------> mips cpu interrupt
  	 *   32-63	  ------> bonito irq
  	 */
  
  	/* setup cs5536 as high level trigger */
  	LOONGSON_INTPOL = LOONGSON_INT_BIT_INT0 | LOONGSON_INT_BIT_INT1;
  	LOONGSON_INTEDGE &= ~(LOONGSON_INT_BIT_INT0 | LOONGSON_INT_BIT_INT1);
  
  	/* Sets the first-level interrupt dispatcher. */
  	mips_cpu_irq_init();
  	init_i8259_irqs();
  	bonito_irq_init();
  
  	/* setup north bridge irq (bonito) */
  	setup_irq(LOONGSON_NORTH_BRIDGE_IRQ, &ip6_irqaction);
  	/* setup source bridge irq (i8259) */
  	setup_irq(LOONGSON_SOUTH_BRIDGE_IRQ, &cascade_irqaction);
  }