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
245
246
247
248
249
250
251
252
|
/*
* 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/io.h>
#include <asm/irq.h>
#include <asm/processor.h>
#include <asm/uaccess.h>
#include <asm/thread_info.h>
#include <asm/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)
int show_interrupts(struct seq_file *p, void *v)
{
int i = *(loff_t *) v, j;
struct irqaction * action;
unsigned long flags;
if (i == 0) {
seq_puts(p, " ");
for_each_online_cpu(j)
seq_printf(p, "CPU%d ",j);
seq_putc(p, '\n');
}
if (i < NR_IRQS) {
spin_lock_irqsave(&irq_desc[i].lock, flags);
action = irq_desc[i].action;
if (!action)
goto unlock;
seq_printf(p, "%3d: ",i);
for_each_online_cpu(j)
seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
seq_printf(p, " %14s", irq_desc[i].chip->name);
seq_printf(p, "-%-8s", irq_desc[i].name);
seq_printf(p, " %s", action->name);
for (action=action->next; action; action = action->next)
seq_printf(p, ", %s", action->name);
seq_putc(p, '\n');
unlock:
spin_unlock_irqrestore(&irq_desc[i].lock, flags);
} else if (i == NR_IRQS)
seq_printf(p, "Err: %10u\n", atomic_read(&irq_err_count));
return 0;
}
#endif
#ifdef CONFIG_4KSTACKS
/*
* 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];
static union irq_ctx *softirq_ctx[NR_CPUS];
#endif
asmlinkage int do_IRQ(unsigned long r4, unsigned long r5,
unsigned long r6, unsigned long r7,
struct pt_regs __regs)
{
struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
struct pt_regs *old_regs = set_irq_regs(regs);
int irq;
#ifdef CONFIG_4KSTACKS
union irq_ctx *curctx, *irqctx;
#endif
irq_enter();
#ifdef CONFIG_DEBUG_STACKOVERFLOW
/* Debugging check for stack overflow: is there less than 1KB free? */
{
long sp;
__asm__ __volatile__ ("and r15, %0" :
"=r" (sp) : "0" (THREAD_SIZE - 1));
if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
printk("do_IRQ: stack overflow: %ld\n",
sp - sizeof(struct thread_info));
dump_stack();
}
}
#endif
#ifdef CONFIG_CPU_HAS_INTEVT
irq = (ctrl_inl(INTEVT) >> 5) - 16;
#else
irq = r4;
#endif
irq = irq_demux(irq);
#ifdef CONFIG_4KSTACKS
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;
__asm__ __volatile__ (
"mov %0, r4 \n"
"mov r15, r9 \n"
"jsr @%1 \n"
/* swith to the irq stack */
" mov %2, r15 \n"
/* restore the stack (ring zero) */
"mov r9, r15 \n"
: /* no outputs */
: "r" (irq), "r" (generic_handle_irq), "r" (isp)
/* XXX: A somewhat excessive clobber list? -PFM */
: "memory", "r0", "r1", "r2", "r3", "r4",
"r5", "r6", "r7", "r8", "t", "pr"
);
} else
#endif
generic_handle_irq(irq);
irq_exit();
set_irq_regs(old_regs);
return 1;
}
#ifdef CONFIG_4KSTACKS
/*
* These should really be __section__(".bss.page_aligned") as well, but
* gcc's 3.0 and earlier don't handle that correctly.
*/
static char softirq_stack[NR_CPUS * THREAD_SIZE]
__attribute__((__aligned__(THREAD_SIZE)));
static char hardirq_stack[NR_CPUS * THREAD_SIZE]
__attribute__((__aligned__(THREAD_SIZE)));
/*
* 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.exec_domain = 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.exec_domain = NULL;
irqctx->tinfo.cpu = cpu;
irqctx->tinfo.preempt_count = SOFTIRQ_OFFSET;
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;
}
extern asmlinkage void __do_softirq(void);
asmlinkage void do_softirq(void)
{
unsigned long flags;
struct thread_info *curctx;
union irq_ctx *irqctx;
u32 *isp;
if (in_interrupt())
return;
local_irq_save(flags);
if (local_softirq_pending()) {
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)
/* XXX: A somewhat excessive clobber list? -PFM */
: "memory", "r0", "r1", "r2", "r3", "r4",
"r5", "r6", "r7", "r8", "r9", "r15", "t", "pr"
);
}
local_irq_restore(flags);
}
EXPORT_SYMBOL(do_softirq);
#endif
|
