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
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
|
/*
* linux/arch/sh/kernel/irq.c
*
* Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
*
*
* SuperH version: Copyright (C) 1999 Niibe Yutaka
*/
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/kernel_stat.h>
#include <linux/seq_file.h>
#include <linux/ftrace.h>
#include <linux/delay.h>
#include <linux/ratelimit.h>
#include <asm/processor.h>
#include <asm/machvec.h>
#include <linux/uaccess.h>
#include <asm/thread_info.h>
#include <cpu/mmu_context.h>
atomic_t irq_err_count;
/*
* 'what should we do if we get a hw irq event on an illegal vector'.
* each architecture has to answer this themselves, it doesn't deserve
* a generic callback i think.
*/
void ack_bad_irq(unsigned int irq)
{
atomic_inc(&irq_err_count);
printk("unexpected IRQ trap at vector %02x\n", irq);
}
#if defined(CONFIG_PROC_FS)
/*
* /proc/interrupts printing for arch specific interrupts
*/
int arch_show_interrupts(struct seq_file *p, int prec)
{
int j;
seq_printf(p, "%*s: ", prec, "NMI");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stat[j].__nmi_count);
seq_printf(p, " Non-maskable interrupts\n");
seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
return 0;
}
#endif
#ifdef CONFIG_IRQSTACKS
/*
* per-CPU IRQ handling contexts (thread information and stack)
*/
union irq_ctx {
struct thread_info tinfo;
u32 stack[THREAD_SIZE/sizeof(u32)];
};
static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly;
static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly;
static char softirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss;
static char hardirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss;
static inline void handle_one_irq(unsigned int irq)
{
union irq_ctx *curctx, *irqctx;
curctx = (union irq_ctx *)current_thread_info();
irqctx = hardirq_ctx[smp_processor_id()];
/*
* this is where we switch to the IRQ stack. However, if we are
* already using the IRQ stack (because we interrupted a hardirq
* handler) we can't do that and just have to keep using the
* current stack (which is the irq stack already after all)
*/
if (curctx != irqctx) {
u32 *isp;
isp = (u32 *)((char *)irqctx + sizeof(*irqctx));
irqctx->tinfo.task = curctx->tinfo.task;
irqctx->tinfo.previous_sp = current_stack_pointer;
/*
* Copy the softirq bits in preempt_count so that the
* softirq checks work in the hardirq context.
*/
irqctx->tinfo.preempt_count =
(irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) |
(curctx->tinfo.preempt_count & SOFTIRQ_MASK);
__asm__ __volatile__ (
"mov %0, r4 \n"
"mov r15, r8 \n"
"jsr @%1 \n"
/* switch to the irq stack */
" mov %2, r15 \n"
/* restore the stack (ring zero) */
"mov r8, r15 \n"
: /* no outputs */
: "r" (irq), "r" (generic_handle_irq), "r" (isp)
: "memory", "r0", "r1", "r2", "r3", "r4",
"r5", "r6", "r7", "r8", "t", "pr"
);
} else
generic_handle_irq(irq);
}
/*
* allocate per-cpu stacks for hardirq and for softirq processing
*/
void irq_ctx_init(int cpu)
{
union irq_ctx *irqctx;
if (hardirq_ctx[cpu])
return;
irqctx = (union irq_ctx *)&hardirq_stack[cpu * THREAD_SIZE];
irqctx->tinfo.task = NULL;
irqctx->tinfo.cpu = cpu;
irqctx->tinfo.preempt_count = HARDIRQ_OFFSET;
irqctx->tinfo.addr_limit = MAKE_MM_SEG(0);
hardirq_ctx[cpu] = irqctx;
irqctx = (union irq_ctx *)&softirq_stack[cpu * THREAD_SIZE];
irqctx->tinfo.task = NULL;
irqctx->tinfo.cpu = cpu;
irqctx->tinfo.preempt_count = 0;
irqctx->tinfo.addr_limit = MAKE_MM_SEG(0);
softirq_ctx[cpu] = irqctx;
printk("CPU %u irqstacks, hard=%p soft=%p\n",
cpu, hardirq_ctx[cpu], softirq_ctx[cpu]);
}
void irq_ctx_exit(int cpu)
{
hardirq_ctx[cpu] = NULL;
}
void do_softirq_own_stack(void)
{
struct thread_info *curctx;
union irq_ctx *irqctx;
u32 *isp;
curctx = current_thread_info();
irqctx = softirq_ctx[smp_processor_id()];
irqctx->tinfo.task = curctx->task;
irqctx->tinfo.previous_sp = current_stack_pointer;
/* build the stack frame on the softirq stack */
isp = (u32 *)((char *)irqctx + sizeof(*irqctx));
__asm__ __volatile__ (
"mov r15, r9 \n"
"jsr @%0 \n"
/* switch to the softirq stack */
" mov %1, r15 \n"
/* restore the thread stack */
"mov r9, r15 \n"
: /* no outputs */
: "r" (__do_softirq), "r" (isp)
: "memory", "r0", "r1", "r2", "r3", "r4",
"r5", "r6", "r7", "r8", "r9", "r15", "t", "pr"
);
}
#else
static inline void handle_one_irq(unsigned int irq)
{
generic_handle_irq(irq);
}
#endif
asmlinkage __irq_entry int do_IRQ(unsigned int irq, struct pt_regs *regs)
{
struct pt_regs *old_regs = set_irq_regs(regs);
irq_enter();
irq = irq_demux(irq_lookup(irq));
if (irq != NO_IRQ_IGNORE) {
handle_one_irq(irq);
irq_finish(irq);
}
irq_exit();
set_irq_regs(old_regs);
return IRQ_HANDLED;
}
void __init init_IRQ(void)
{
plat_irq_setup();
/* Perform the machine specific initialisation */
if (sh_mv.mv_init_irq)
sh_mv.mv_init_irq();
intc_finalize();
irq_ctx_init(smp_processor_id());
}
#ifdef CONFIG_HOTPLUG_CPU
/*
* The CPU has been marked offline. Migrate IRQs off this CPU. If
* the affinity settings do not allow other CPUs, force them onto any
* available CPU.
*/
void migrate_irqs(void)
{
unsigned int irq, cpu = smp_processor_id();
for_each_active_irq(irq) {
struct irq_data *data = irq_get_irq_data(irq);
if (irq_data_get_node(data) == cpu) {
struct cpumask *mask = irq_data_get_affinity_mask(data);
unsigned int newcpu = cpumask_any_and(mask,
cpu_online_mask);
if (newcpu >= nr_cpu_ids) {
pr_info_ratelimited("IRQ%u no longer affine to CPU%u\n",
irq, cpu);
cpumask_setall(mask);
}
irq_set_affinity(irq, mask);
}
}
}
#endif
|
