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
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
|
/*
* Copyright (C) 2014 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_EXCEPTIONS 16
struct bcr_irq_arcv2 {
#ifdef CONFIG_CPU_BIG_ENDIAN
unsigned int pad:3, firq:1, prio:4, exts:8, irqs:8, ver:8;
#else
unsigned int ver:8, irqs:8, exts:8, prio:4, firq:1, pad:3;
#endif
};
/*
* Early Hardware specific Interrupt setup
* -Called very early (start_kernel -> setup_arch -> setup_processor)
* -Platform Independent (must for any ARC Core)
* -Needed for each CPU (hence not foldable into init_IRQ)
*/
void arc_init_IRQ(void)
{
unsigned int tmp, irq_prio, i;
struct bcr_irq_arcv2 irq_bcr;
struct aux_irq_ctrl {
#ifdef CONFIG_CPU_BIG_ENDIAN
unsigned int res3:18, save_idx_regs:1, res2:1,
save_u_to_u:1, save_lp_regs:1, save_blink:1,
res:4, save_nr_gpr_pairs:5;
#else
unsigned int save_nr_gpr_pairs:5, res:4,
save_blink:1, save_lp_regs:1, save_u_to_u:1,
res2:1, save_idx_regs:1, res3:18;
#endif
} ictrl;
*(unsigned int *)&ictrl = 0;
ictrl.save_nr_gpr_pairs = 6; /* r0 to r11 (r12 saved manually) */
ictrl.save_blink = 1;
ictrl.save_lp_regs = 1; /* LP_COUNT, LP_START, LP_END */
ictrl.save_u_to_u = 0; /* user ctxt saved on kernel stack */
ictrl.save_idx_regs = 1; /* JLI, LDI, EI */
WRITE_AUX(AUX_IRQ_CTRL, ictrl);
/*
* ARCv2 core intc provides multiple interrupt priorities (upto 16).
* Typical builds though have only two levels (0-high, 1-low)
* Linux by default uses lower prio 1 for most irqs, reserving 0 for
* NMI style interrupts in future (say perf)
*/
READ_BCR(ARC_REG_IRQ_BCR, irq_bcr);
irq_prio = irq_bcr.prio; /* Encoded as N-1 for N levels */
pr_info("archs-intc\t: %d priority levels (default %d)%s\n",
irq_prio + 1, ARCV2_IRQ_DEF_PRIO,
irq_bcr.firq ? " FIRQ (not used)":"");
/*
* Set a default priority for all available interrupts to prevent
* switching of register banks if Fast IRQ and multiple register banks
* are supported by CPU.
* Also disable all IRQ lines so faulty external hardware won't
* trigger interrupt that kernel is not ready to handle.
*/
for (i = NR_EXCEPTIONS; i < irq_bcr.irqs + NR_EXCEPTIONS; i++) {
write_aux_reg(AUX_IRQ_SELECT, i);
write_aux_reg(AUX_IRQ_PRIORITY, ARCV2_IRQ_DEF_PRIO);
write_aux_reg(AUX_IRQ_ENABLE, 0);
}
/* setup status32, don't enable intr yet as kernel doesn't want */
tmp = read_aux_reg(ARC_REG_STATUS32);
tmp |= STATUS_AD_MASK | (ARCV2_IRQ_DEF_PRIO << 1);
tmp &= ~STATUS_IE_MASK;
asm volatile("kflag %0 \n"::"r"(tmp));
}
static void arcv2_irq_mask(struct irq_data *data)
{
write_aux_reg(AUX_IRQ_SELECT, data->hwirq);
write_aux_reg(AUX_IRQ_ENABLE, 0);
}
static void arcv2_irq_unmask(struct irq_data *data)
{
write_aux_reg(AUX_IRQ_SELECT, data->hwirq);
write_aux_reg(AUX_IRQ_ENABLE, 1);
}
void arcv2_irq_enable(struct irq_data *data)
{
/* set default priority */
write_aux_reg(AUX_IRQ_SELECT, data->hwirq);
write_aux_reg(AUX_IRQ_PRIORITY, ARCV2_IRQ_DEF_PRIO);
/*
* hw auto enables (linux unmask) all by default
* So no need to do IRQ_ENABLE here
* XXX: However OSCI LAN need it
*/
write_aux_reg(AUX_IRQ_ENABLE, 1);
}
static struct irq_chip arcv2_irq_chip = {
.name = "ARCv2 core Intc",
.irq_mask = arcv2_irq_mask,
.irq_unmask = arcv2_irq_unmask,
.irq_enable = arcv2_irq_enable
};
static int arcv2_irq_map(struct irq_domain *d, unsigned int irq,
irq_hw_number_t hw)
{
/*
* core intc IRQs [16, 23]:
* Statically assigned always private-per-core (Timers, WDT, IPI, PCT)
*/
if (hw < FIRST_EXT_IRQ) {
/*
* A subsequent request_percpu_irq() fails if percpu_devid is
* not set. That in turns sets NOAUTOEN, meaning each core needs
* to call enable_percpu_irq()
*/
irq_set_percpu_devid(irq);
irq_set_chip_and_handler(irq, &arcv2_irq_chip, handle_percpu_irq);
} else {
irq_set_chip_and_handler(irq, &arcv2_irq_chip, handle_level_irq);
}
return 0;
}
static const struct irq_domain_ops arcv2_irq_ops = {
.xlate = irq_domain_xlate_onecell,
.map = arcv2_irq_map,
};
static int __init
init_onchip_IRQ(struct device_node *intc, struct device_node *parent)
{
struct irq_domain *root_domain;
struct bcr_irq_arcv2 irq_bcr;
unsigned int nr_cpu_irqs;
READ_BCR(ARC_REG_IRQ_BCR, irq_bcr);
nr_cpu_irqs = irq_bcr.irqs + NR_EXCEPTIONS;
if (parent)
panic("DeviceTree incore intc not a root irq controller\n");
root_domain = irq_domain_add_linear(intc, nr_cpu_irqs, &arcv2_irq_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);
#ifdef CONFIG_SMP
irq_create_mapping(root_domain, IPI_IRQ);
#endif
irq_create_mapping(root_domain, SOFTIRQ_IRQ);
return 0;
}
IRQCHIP_DECLARE(arc_intc, "snps,archs-intc", init_onchip_IRQ);
|
