1 // SPDX-License-Identifier: GPL-2.0
2
3 #include <linux/delay.h>
4 #include <linux/interrupt.h>
5 #include <linux/irq.h>
6 #include <linux/kernel.h>
7 #include <linux/sched.h>
8 #include <linux/sched/debug.h>
9 #include <linux/types.h>
10 #include <linux/ioport.h>
11
12 #include <asm/hwtest.h>
13 #include <asm/irq.h>
14 #include <asm/irq_regs.h>
15 #include <asm/virt.h>
16
17 #define GFPIC_REG_IRQ_PENDING 0x04
18 #define GFPIC_REG_IRQ_DISABLE_ALL 0x08
19 #define GFPIC_REG_IRQ_DISABLE 0x0c
20 #define GFPIC_REG_IRQ_ENABLE 0x10
21
22 extern void show_registers(struct pt_regs *regs);
23
24 static struct resource picres[6];
25 static const char *picname[6] = {
26 "goldfish_pic.0",
27 "goldfish_pic.1",
28 "goldfish_pic.2",
29 "goldfish_pic.3",
30 "goldfish_pic.4",
31 "goldfish_pic.5"
32 };
33
34 /*
35 * 6 goldfish-pic for CPU IRQ #1 to IRQ #6
36 * CPU IRQ #1 -> PIC #1
37 * IRQ #1 to IRQ #31 -> unused
38 * IRQ #32 -> goldfish-tty
39 * CPU IRQ #2 -> PIC #2
40 * IRQ #1 to IRQ #32 -> virtio-mmio from 1 to 32
41 * CPU IRQ #3 -> PIC #3
42 * IRQ #1 to IRQ #32 -> virtio-mmio from 33 to 64
43 * CPU IRQ #4 -> PIC #4
44 * IRQ #1 to IRQ #32 -> virtio-mmio from 65 to 96
45 * CPU IRQ #5 -> PIC #5
46 * IRQ #1 to IRQ #32 -> virtio-mmio from 97 to 128
47 * CPU IRQ #6 -> PIC #6
48 * IRQ #1 -> goldfish-timer
49 * IRQ #2 -> goldfish-rtc
50 * IRQ #3 to IRQ #32 -> unused
51 * CPU IRQ #7 -> NMI
52 */
53
gfpic_read(int pic,int reg)54 static u32 gfpic_read(int pic, int reg)
55 {
56 void __iomem *base = (void __iomem *)(virt_bi_data.pic.mmio +
57 pic * 0x1000);
58
59 return ioread32be(base + reg);
60 }
61
gfpic_write(u32 value,int pic,int reg)62 static void gfpic_write(u32 value, int pic, int reg)
63 {
64 void __iomem *base = (void __iomem *)(virt_bi_data.pic.mmio +
65 pic * 0x1000);
66
67 iowrite32be(value, base + reg);
68 }
69
70 #define GF_PIC(irq) ((irq - IRQ_USER) / 32)
71 #define GF_IRQ(irq) ((irq - IRQ_USER) % 32)
72
virt_irq_enable(struct irq_data * data)73 static void virt_irq_enable(struct irq_data *data)
74 {
75 gfpic_write(BIT(GF_IRQ(data->irq)), GF_PIC(data->irq),
76 GFPIC_REG_IRQ_ENABLE);
77 }
78
virt_irq_disable(struct irq_data * data)79 static void virt_irq_disable(struct irq_data *data)
80 {
81 gfpic_write(BIT(GF_IRQ(data->irq)), GF_PIC(data->irq),
82 GFPIC_REG_IRQ_DISABLE);
83 }
84
virt_irq_startup(struct irq_data * data)85 static unsigned int virt_irq_startup(struct irq_data *data)
86 {
87 virt_irq_enable(data);
88 return 0;
89 }
90
virt_nmi_handler(int irq,void * dev_id)91 static irqreturn_t virt_nmi_handler(int irq, void *dev_id)
92 {
93 static int in_nmi;
94
95 if (READ_ONCE(in_nmi))
96 return IRQ_HANDLED;
97 WRITE_ONCE(in_nmi, 1);
98
99 pr_warn("Non-Maskable Interrupt\n");
100 show_registers(get_irq_regs());
101
102 WRITE_ONCE(in_nmi, 0);
103 return IRQ_HANDLED;
104 }
105
106 static struct irq_chip virt_irq_chip = {
107 .name = "virt",
108 .irq_enable = virt_irq_enable,
109 .irq_disable = virt_irq_disable,
110 .irq_startup = virt_irq_startup,
111 .irq_shutdown = virt_irq_disable,
112 };
113
goldfish_pic_irq(struct irq_desc * desc)114 static void goldfish_pic_irq(struct irq_desc *desc)
115 {
116 u32 irq_pending;
117 unsigned int irq_num;
118 unsigned int pic = desc->irq_data.irq - 1;
119
120 irq_pending = gfpic_read(pic, GFPIC_REG_IRQ_PENDING);
121 irq_num = IRQ_USER + pic * 32;
122
123 do {
124 if (irq_pending & 1)
125 generic_handle_irq(irq_num);
126 ++irq_num;
127 irq_pending >>= 1;
128 } while (irq_pending);
129 }
130
virt_init_IRQ(void)131 void __init virt_init_IRQ(void)
132 {
133 unsigned int i;
134
135 m68k_setup_irq_controller(&virt_irq_chip, handle_simple_irq, IRQ_USER,
136 NUM_VIRT_SOURCES - IRQ_USER);
137
138 for (i = 0; i < 6; i++) {
139
140 picres[i] = (struct resource)
141 DEFINE_RES_MEM_NAMED(virt_bi_data.pic.mmio + i * 0x1000,
142 0x1000, picname[i]);
143 if (request_resource(&iomem_resource, &picres[i])) {
144 pr_err("Cannot allocate %s resource\n", picname[i]);
145 return;
146 }
147
148 irq_set_chained_handler(virt_bi_data.pic.irq + i,
149 goldfish_pic_irq);
150 }
151
152 if (request_irq(IRQ_AUTO_7, virt_nmi_handler, 0, "NMI",
153 virt_nmi_handler))
154 pr_err("Couldn't register NMI\n");
155 }
156