summaryrefslogtreecommitdiff
path: root/arch/cris/arch-v32/kernel/irq.c
blob: 2ed48ae3d313cb71e086c02fb0b45f5362b9e685 (plain)
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
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
/*
 * Copyright (C) 2003, Axis Communications AB.
 */

#include <asm/irq.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/smp.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/profile.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/threads.h>
#include <linux/spinlock.h>
#include <linux/kernel_stat.h>
#include <hwregs/reg_map.h>
#include <hwregs/reg_rdwr.h>
#include <hwregs/intr_vect.h>
#include <hwregs/intr_vect_defs.h>

#define CPU_FIXED -1

/* IRQ masks (refer to comment for crisv32_do_multiple) */
#if TIMER0_INTR_VECT - FIRST_IRQ < 32
#define TIMER_MASK (1 << (TIMER0_INTR_VECT - FIRST_IRQ))
#undef TIMER_VECT1
#else
#define TIMER_MASK (1 << (TIMER0_INTR_VECT - FIRST_IRQ - 32))
#define TIMER_VECT1
#endif
#ifdef CONFIG_ETRAX_KGDB
#if defined(CONFIG_ETRAX_KGDB_PORT0)
#define IGNOREMASK (1 << (SER0_INTR_VECT - FIRST_IRQ))
#elif defined(CONFIG_ETRAX_KGDB_PORT1)
#define IGNOREMASK (1 << (SER1_INTR_VECT - FIRST_IRQ))
#elif defined(CONFIG_ETRAX_KGB_PORT2)
#define IGNOREMASK (1 << (SER2_INTR_VECT - FIRST_IRQ))
#elif defined(CONFIG_ETRAX_KGDB_PORT3)
#define IGNOREMASK (1 << (SER3_INTR_VECT - FIRST_IRQ))
#endif
#endif

DEFINE_SPINLOCK(irq_lock);

struct cris_irq_allocation
{
  int cpu; /* The CPU to which the IRQ is currently allocated. */
  cpumask_t mask; /* The CPUs to which the IRQ may be allocated. */
};

struct cris_irq_allocation irq_allocations[NR_REAL_IRQS] =
  { [0 ... NR_REAL_IRQS - 1] = {0, CPU_MASK_ALL} };

static unsigned long irq_regs[NR_CPUS] =
{
  regi_irq,
#ifdef CONFIG_SMP
  regi_irq2,
#endif
};

#if NR_REAL_IRQS > 32
#define NBR_REGS 2
#else
#define NBR_REGS 1
#endif

unsigned long cpu_irq_counters[NR_CPUS];
unsigned long irq_counters[NR_REAL_IRQS];

/* From irq.c. */
extern void weird_irq(void);

/* From entry.S. */
extern void system_call(void);
extern void nmi_interrupt(void);
extern void multiple_interrupt(void);
extern void gdb_handle_exception(void);
extern void i_mmu_refill(void);
extern void i_mmu_invalid(void);
extern void i_mmu_access(void);
extern void i_mmu_execute(void);
extern void d_mmu_refill(void);
extern void d_mmu_invalid(void);
extern void d_mmu_access(void);
extern void d_mmu_write(void);

/* From kgdb.c. */
extern void kgdb_init(void);
extern void breakpoint(void);

/* From traps.c.  */
extern void breakh_BUG(void);

/*
 * Build the IRQ handler stubs using macros from irq.h.
 */
#ifdef CONFIG_CRIS_MACH_ARTPEC3
BUILD_TIMER_IRQ(0x31, 0)
#else
BUILD_IRQ(0x31)
#endif
BUILD_IRQ(0x32)
BUILD_IRQ(0x33)
BUILD_IRQ(0x34)
BUILD_IRQ(0x35)
BUILD_IRQ(0x36)
BUILD_IRQ(0x37)
BUILD_IRQ(0x38)
BUILD_IRQ(0x39)
BUILD_IRQ(0x3a)
BUILD_IRQ(0x3b)
BUILD_IRQ(0x3c)
BUILD_IRQ(0x3d)
BUILD_IRQ(0x3e)
BUILD_IRQ(0x3f)
BUILD_IRQ(0x40)
BUILD_IRQ(0x41)
BUILD_IRQ(0x42)
BUILD_IRQ(0x43)
BUILD_IRQ(0x44)
BUILD_IRQ(0x45)
BUILD_IRQ(0x46)
BUILD_IRQ(0x47)
BUILD_IRQ(0x48)
BUILD_IRQ(0x49)
BUILD_IRQ(0x4a)
#ifdef CONFIG_ETRAXFS
BUILD_TIMER_IRQ(0x4b, 0)
#else
BUILD_IRQ(0x4b)
#endif
BUILD_IRQ(0x4c)
BUILD_IRQ(0x4d)
BUILD_IRQ(0x4e)
BUILD_IRQ(0x4f)
BUILD_IRQ(0x50)
#if MACH_IRQS > 32
BUILD_IRQ(0x51)
BUILD_IRQ(0x52)
BUILD_IRQ(0x53)
BUILD_IRQ(0x54)
BUILD_IRQ(0x55)
BUILD_IRQ(0x56)
BUILD_IRQ(0x57)
BUILD_IRQ(0x58)
BUILD_IRQ(0x59)
BUILD_IRQ(0x5a)
BUILD_IRQ(0x5b)
BUILD_IRQ(0x5c)
BUILD_IRQ(0x5d)
BUILD_IRQ(0x5e)
BUILD_IRQ(0x5f)
BUILD_IRQ(0x60)
BUILD_IRQ(0x61)
BUILD_IRQ(0x62)
BUILD_IRQ(0x63)
BUILD_IRQ(0x64)
BUILD_IRQ(0x65)
BUILD_IRQ(0x66)
BUILD_IRQ(0x67)
BUILD_IRQ(0x68)
BUILD_IRQ(0x69)
BUILD_IRQ(0x6a)
BUILD_IRQ(0x6b)
BUILD_IRQ(0x6c)
BUILD_IRQ(0x6d)
BUILD_IRQ(0x6e)
BUILD_IRQ(0x6f)
BUILD_IRQ(0x70)
#endif

/* Pointers to the low-level handlers. */
static void (*interrupt[MACH_IRQS])(void) = {
	IRQ0x31_interrupt, IRQ0x32_interrupt, IRQ0x33_interrupt,
	IRQ0x34_interrupt, IRQ0x35_interrupt, IRQ0x36_interrupt,
	IRQ0x37_interrupt, IRQ0x38_interrupt, IRQ0x39_interrupt,
	IRQ0x3a_interrupt, IRQ0x3b_interrupt, IRQ0x3c_interrupt,
	IRQ0x3d_interrupt, IRQ0x3e_interrupt, IRQ0x3f_interrupt,
	IRQ0x40_interrupt, IRQ0x41_interrupt, IRQ0x42_interrupt,
	IRQ0x43_interrupt, IRQ0x44_interrupt, IRQ0x45_interrupt,
	IRQ0x46_interrupt, IRQ0x47_interrupt, IRQ0x48_interrupt,
	IRQ0x49_interrupt, IRQ0x4a_interrupt, IRQ0x4b_interrupt,
	IRQ0x4c_interrupt, IRQ0x4d_interrupt, IRQ0x4e_interrupt,
	IRQ0x4f_interrupt, IRQ0x50_interrupt,
#if MACH_IRQS > 32
	IRQ0x51_interrupt, IRQ0x52_interrupt, IRQ0x53_interrupt,
	IRQ0x54_interrupt, IRQ0x55_interrupt, IRQ0x56_interrupt,
	IRQ0x57_interrupt, IRQ0x58_interrupt, IRQ0x59_interrupt,
	IRQ0x5a_interrupt, IRQ0x5b_interrupt, IRQ0x5c_interrupt,
	IRQ0x5d_interrupt, IRQ0x5e_interrupt, IRQ0x5f_interrupt,
	IRQ0x60_interrupt, IRQ0x61_interrupt, IRQ0x62_interrupt,
	IRQ0x63_interrupt, IRQ0x64_interrupt, IRQ0x65_interrupt,
	IRQ0x66_interrupt, IRQ0x67_interrupt, IRQ0x68_interrupt,
	IRQ0x69_interrupt, IRQ0x6a_interrupt, IRQ0x6b_interrupt,
	IRQ0x6c_interrupt, IRQ0x6d_interrupt, IRQ0x6e_interrupt,
	IRQ0x6f_interrupt, IRQ0x70_interrupt,
#endif
};

void
block_irq(int irq, int cpu)
{
	int intr_mask;
        unsigned long flags;

	spin_lock_irqsave(&irq_lock, flags);
	/* Remember, 1 let thru, 0 block. */
	if (irq - FIRST_IRQ < 32) {
		intr_mask = REG_RD_INT_VECT(intr_vect, irq_regs[cpu],
			rw_mask, 0);
		intr_mask &= ~(1 << (irq - FIRST_IRQ));
		REG_WR_INT_VECT(intr_vect, irq_regs[cpu], rw_mask,
			0, intr_mask);
	} else {
		intr_mask = REG_RD_INT_VECT(intr_vect, irq_regs[cpu],
			rw_mask, 1);
		intr_mask &= ~(1 << (irq - FIRST_IRQ - 32));
		REG_WR_INT_VECT(intr_vect, irq_regs[cpu], rw_mask,
			1, intr_mask);
	}
        spin_unlock_irqrestore(&irq_lock, flags);
}

void
unblock_irq(int irq, int cpu)
{
	int intr_mask;
        unsigned long flags;

        spin_lock_irqsave(&irq_lock, flags);
	/* Remember, 1 let thru, 0 block. */
	if (irq - FIRST_IRQ < 32) {
		intr_mask = REG_RD_INT_VECT(intr_vect, irq_regs[cpu],
			rw_mask, 0);
		intr_mask |= (1 << (irq - FIRST_IRQ));
		REG_WR_INT_VECT(intr_vect, irq_regs[cpu], rw_mask,
			0, intr_mask);
	} else {
		intr_mask = REG_RD_INT_VECT(intr_vect, irq_regs[cpu],
			rw_mask, 1);
		intr_mask |= (1 << (irq - FIRST_IRQ - 32));
		REG_WR_INT_VECT(intr_vect, irq_regs[cpu], rw_mask,
			1, intr_mask);
	}
        spin_unlock_irqrestore(&irq_lock, flags);
}

/* Find out which CPU the irq should be allocated to. */
static int irq_cpu(int irq)
{
	int cpu;
        unsigned long flags;

        spin_lock_irqsave(&irq_lock, flags);
        cpu = irq_allocations[irq - FIRST_IRQ].cpu;

	/* Fixed interrupts stay on the local CPU. */
	if (cpu == CPU_FIXED)
        {
		spin_unlock_irqrestore(&irq_lock, flags);
		return smp_processor_id();
        }


	/* Let the interrupt stay if possible */
	if (cpu_isset(cpu, irq_allocations[irq - FIRST_IRQ].mask))
		goto out;

	/* IRQ must be moved to another CPU. */
	cpu = first_cpu(irq_allocations[irq - FIRST_IRQ].mask);
	irq_allocations[irq - FIRST_IRQ].cpu = cpu;
out:
	spin_unlock_irqrestore(&irq_lock, flags);
	return cpu;
}

void crisv32_mask_irq(int irq)
{
	int cpu;

	for (cpu = 0; cpu < NR_CPUS; cpu++)
		block_irq(irq, cpu);
}

void crisv32_unmask_irq(int irq)
{
	unblock_irq(irq, irq_cpu(irq));
}


static unsigned int startup_crisv32_irq(unsigned int irq)
{
	crisv32_unmask_irq(irq);
	return 0;
}

static void shutdown_crisv32_irq(unsigned int irq)
{
	crisv32_mask_irq(irq);
}

static void enable_crisv32_irq(unsigned int irq)
{
	crisv32_unmask_irq(irq);
}

static void disable_crisv32_irq(unsigned int irq)
{
	crisv32_mask_irq(irq);
}

static void ack_crisv32_irq(unsigned int irq)
{
}

static void end_crisv32_irq(unsigned int irq)
{
}

int set_affinity_crisv32_irq(unsigned int irq, const struct cpumask *dest)
{
	unsigned long flags;
	spin_lock_irqsave(&irq_lock, flags);
	irq_allocations[irq - FIRST_IRQ].mask = *dest;
	spin_unlock_irqrestore(&irq_lock, flags);

	return 0;
}

static struct irq_chip crisv32_irq_type = {
	.name =        "CRISv32",
	.startup =     startup_crisv32_irq,
	.shutdown =    shutdown_crisv32_irq,
	.enable =      enable_crisv32_irq,
	.disable =     disable_crisv32_irq,
	.ack =         ack_crisv32_irq,
	.end =         end_crisv32_irq,
	.set_affinity = set_affinity_crisv32_irq
};

void
set_exception_vector(int n, irqvectptr addr)
{
	etrax_irv->v[n] = (irqvectptr) addr;
}

extern void do_IRQ(int irq, struct pt_regs * regs);

void
crisv32_do_IRQ(int irq, int block, struct pt_regs* regs)
{
	/* Interrupts that may not be moved to another CPU and
         * are IRQF_DISABLED may skip blocking. This is currently
         * only valid for the timer IRQ and the IPI and is used
         * for the timer interrupt to avoid watchdog starvation.
         */
	if (!block) {
		do_IRQ(irq, regs);
		return;
	}

	block_irq(irq, smp_processor_id());
	do_IRQ(irq, regs);

	unblock_irq(irq, irq_cpu(irq));
}

/* If multiple interrupts occur simultaneously we get a multiple
 * interrupt from the CPU and software has to sort out which
 * interrupts that happened. There are two special cases here:
 *
 * 1. Timer interrupts may never be blocked because of the
 *    watchdog (refer to comment in include/asr/arch/irq.h)
 * 2. GDB serial port IRQs are unhandled here and will be handled
 *    as a single IRQ when it strikes again because the GDB
 *    stubb wants to save the registers in its own fashion.
 */
void
crisv32_do_multiple(struct pt_regs* regs)
{
	int cpu;
	int mask;
	int masked[NBR_REGS];
	int bit;
	int i;

	cpu = smp_processor_id();

	/* An extra irq_enter here to prevent softIRQs to run after
         * each do_IRQ. This will decrease the interrupt latency.
	 */
	irq_enter();

	for (i = 0; i < NBR_REGS; i++) {
		/* Get which IRQs that happend. */
		masked[i] = REG_RD_INT_VECT(intr_vect, irq_regs[cpu],
			r_masked_vect, i);

		/* Calculate new IRQ mask with these IRQs disabled. */
		mask = REG_RD_INT_VECT(intr_vect, irq_regs[cpu], rw_mask, i);
		mask &= ~masked[i];

	/* Timer IRQ is never masked */
#ifdef TIMER_VECT1
		if ((i == 1) && (masked[0] & TIMER_MASK))
			mask |= TIMER_MASK;
#else
		if ((i == 0) && (masked[0] & TIMER_MASK))
			mask |= TIMER_MASK;
#endif
		/* Block all the IRQs */
		REG_WR_INT_VECT(intr_vect, irq_regs[cpu], rw_mask, i, mask);

	/* Check for timer IRQ and handle it special. */
#ifdef TIMER_VECT1
		if ((i == 1) && (masked[i] & TIMER_MASK)) {
			masked[i] &= ~TIMER_MASK;
			do_IRQ(TIMER0_INTR_VECT, regs);
		}
#else
		if ((i == 0) && (masked[i] & TIMER_MASK)) {
			 masked[i] &= ~TIMER_MASK;
			 do_IRQ(TIMER0_INTR_VECT, regs);
		}
#endif
	}

#ifdef IGNORE_MASK
	/* Remove IRQs that can't be handled as multiple. */
	masked[0] &= ~IGNORE_MASK;
#endif

	/* Handle the rest of the IRQs. */
	for (i = 0; i < NBR_REGS; i++) {
		for (bit = 0; bit < 32; bit++) {
			if (masked[i] & (1 << bit))
				do_IRQ(bit + FIRST_IRQ + i*32, regs);
		}
	}

	/* Unblock all the IRQs. */
	for (i = 0; i < NBR_REGS; i++) {
		mask = REG_RD_INT_VECT(intr_vect, irq_regs[cpu], rw_mask, i);
		mask |= masked[i];
		REG_WR_INT_VECT(intr_vect, irq_regs[cpu], rw_mask, i, mask);
	}

	/* This irq_exit() will trigger the soft IRQs. */
	irq_exit();
}

/*
 * This is called by start_kernel. It fixes the IRQ masks and setup the
 * interrupt vector table to point to bad_interrupt pointers.
 */
void __init
init_IRQ(void)
{
	int i;
	int j;
	reg_intr_vect_rw_mask vect_mask = {0};

	/* Clear all interrupts masks. */
	for (i = 0; i < NBR_REGS; i++)
		REG_WR_VECT(intr_vect, regi_irq, rw_mask, i, vect_mask);

	for (i = 0; i < 256; i++)
		etrax_irv->v[i] = weird_irq;

	/* Point all IRQ's to bad handlers. */
	for (i = FIRST_IRQ, j = 0; j < NR_IRQS; i++, j++) {
		irq_desc[j].chip = &crisv32_irq_type;
		set_exception_vector(i, interrupt[j]);
	}

        /* Mark Timer and IPI IRQs as CPU local */
	irq_allocations[TIMER0_INTR_VECT - FIRST_IRQ].cpu = CPU_FIXED;
	irq_desc[TIMER0_INTR_VECT].status |= IRQ_PER_CPU;
	irq_allocations[IPI_INTR_VECT - FIRST_IRQ].cpu = CPU_FIXED;
	irq_desc[IPI_INTR_VECT].status |= IRQ_PER_CPU;

	set_exception_vector(0x00, nmi_interrupt);
	set_exception_vector(0x30, multiple_interrupt);

	/* Set up handler for various MMU bus faults. */
	set_exception_vector(0x04, i_mmu_refill);
	set_exception_vector(0x05, i_mmu_invalid);
	set_exception_vector(0x06, i_mmu_access);
	set_exception_vector(0x07, i_mmu_execute);
	set_exception_vector(0x08, d_mmu_refill);
	set_exception_vector(0x09, d_mmu_invalid);
	set_exception_vector(0x0a, d_mmu_access);
	set_exception_vector(0x0b, d_mmu_write);

#ifdef CONFIG_BUG
	/* Break 14 handler, used to implement cheap BUG().  */
	set_exception_vector(0x1e, breakh_BUG);
#endif

	/* The system-call trap is reached by "break 13". */
	set_exception_vector(0x1d, system_call);

	/* Exception handlers for debugging, both user-mode and kernel-mode. */

	/* Break 8. */
	set_exception_vector(0x18, gdb_handle_exception);
	/* Hardware single step. */
	set_exception_vector(0x3, gdb_handle_exception);
	/* Hardware breakpoint. */
	set_exception_vector(0xc, gdb_handle_exception);

#ifdef CONFIG_ETRAX_KGDB
	kgdb_init();
	/* Everything is set up; now trap the kernel. */
	breakpoint();
#endif
}