summaryrefslogtreecommitdiffstats
path: root/arch/mips/kernel/irq-gic.c
blob: c01b307317a9635b88394d18164710262e206234 (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
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2008 Ralf Baechle (ralf@linux-mips.org)
 * Copyright (C) 2012 MIPS Technologies, Inc.  All rights reserved.
 */
#include <linux/bitmap.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/irq.h>
#include <linux/clocksource.h>

#include <asm/io.h>
#include <asm/gic.h>
#include <asm/setup.h>
#include <asm/traps.h>
#include <asm/gcmpregs.h>
#include <linux/hardirq.h>
#include <asm-generic/bitops/find.h>

unsigned int gic_frequency;
unsigned int gic_present;
unsigned long _gic_base;
unsigned int gic_irq_base;
unsigned int gic_irq_flags[GIC_NUM_INTRS];

/* The index into this array is the vector # of the interrupt. */
struct gic_shared_intr_map gic_shared_intr_map[GIC_NUM_INTRS];

static struct gic_pcpu_mask pcpu_masks[NR_CPUS];
static struct gic_pending_regs pending_regs[NR_CPUS];
static struct gic_intrmask_regs intrmask_regs[NR_CPUS];

#if defined(CONFIG_CSRC_GIC) || defined(CONFIG_CEVT_GIC)
cycle_t gic_read_count(void)
{
	unsigned int hi, hi2, lo;

	do {
		GICREAD(GIC_REG(SHARED, GIC_SH_COUNTER_63_32), hi);
		GICREAD(GIC_REG(SHARED, GIC_SH_COUNTER_31_00), lo);
		GICREAD(GIC_REG(SHARED, GIC_SH_COUNTER_63_32), hi2);
	} while (hi2 != hi);

	return (((cycle_t) hi) << 32) + lo;
}

void gic_write_compare(cycle_t cnt)
{
	GICWRITE(GIC_REG(VPE_LOCAL, GIC_VPE_COMPARE_HI),
				(int)(cnt >> 32));
	GICWRITE(GIC_REG(VPE_LOCAL, GIC_VPE_COMPARE_LO),
				(int)(cnt & 0xffffffff));
}

cycle_t gic_read_compare(void)
{
	unsigned int hi, lo;

	GICREAD(GIC_REG(VPE_LOCAL, GIC_VPE_COMPARE_HI), hi);
	GICREAD(GIC_REG(VPE_LOCAL, GIC_VPE_COMPARE_LO), lo);

	return (((cycle_t) hi) << 32) + lo;
}
#endif

unsigned int gic_get_timer_pending(void)
{
	unsigned int vpe_pending;

	GICWRITE(GIC_REG(VPE_LOCAL, GIC_VPE_OTHER_ADDR), 0);
	GICREAD(GIC_REG(VPE_OTHER, GIC_VPE_PEND), vpe_pending);
	return (vpe_pending & GIC_VPE_PEND_TIMER_MSK);
}

void gic_bind_eic_interrupt(int irq, int set)
{
	/* Convert irq vector # to hw int # */
	irq -= GIC_PIN_TO_VEC_OFFSET;

	/* Set irq to use shadow set */
	GICWRITE(GIC_REG_ADDR(VPE_LOCAL, GIC_VPE_EIC_SS(irq)), set);
}

void gic_send_ipi(unsigned int intr)
{
	GICWRITE(GIC_REG(SHARED, GIC_SH_WEDGE), 0x80000000 | intr);
}

static void gic_eic_irq_dispatch(void)
{
	unsigned int cause = read_c0_cause();
	int irq;

	irq = (cause & ST0_IM) >> STATUSB_IP2;
	if (irq == 0)
		irq = -1;

	if (irq >= 0)
		do_IRQ(gic_irq_base + irq);
	else
		spurious_interrupt();
}

static void __init vpe_local_setup(unsigned int numvpes)
{
	unsigned long timer_intr = GIC_INT_TMR;
	unsigned long perf_intr = GIC_INT_PERFCTR;
	unsigned int vpe_ctl;
	int i;

	if (cpu_has_veic) {
		/*
		 * GIC timer interrupt -> CPU HW Int X (vector X+2) ->
		 * map to pin X+2-1 (since GIC adds 1)
		 */
		timer_intr += (GIC_CPU_TO_VEC_OFFSET - GIC_PIN_TO_VEC_OFFSET);
		/*
		 * GIC perfcnt interrupt -> CPU HW Int X (vector X+2) ->
		 * map to pin X+2-1 (since GIC adds 1)
		 */
		perf_intr += (GIC_CPU_TO_VEC_OFFSET - GIC_PIN_TO_VEC_OFFSET);
	}

	/*
	 * Setup the default performance counter timer interrupts
	 * for all VPEs
	 */
	for (i = 0; i < numvpes; i++) {
		GICWRITE(GIC_REG(VPE_LOCAL, GIC_VPE_OTHER_ADDR), i);

		/* Are Interrupts locally routable? */
		GICREAD(GIC_REG(VPE_OTHER, GIC_VPE_CTL), vpe_ctl);
		if (vpe_ctl & GIC_VPE_CTL_TIMER_RTBL_MSK)
			GICWRITE(GIC_REG(VPE_OTHER, GIC_VPE_TIMER_MAP),
				 GIC_MAP_TO_PIN_MSK | timer_intr);
		if (cpu_has_veic) {
			set_vi_handler(timer_intr + GIC_PIN_TO_VEC_OFFSET,
				gic_eic_irq_dispatch);
			gic_shared_intr_map[timer_intr + GIC_PIN_TO_VEC_OFFSET].local_intr_mask |= GIC_VPE_RMASK_TIMER_MSK;
		}

		if (vpe_ctl & GIC_VPE_CTL_PERFCNT_RTBL_MSK)
			GICWRITE(GIC_REG(VPE_OTHER, GIC_VPE_PERFCTR_MAP),
				 GIC_MAP_TO_PIN_MSK | perf_intr);
		if (cpu_has_veic) {
			set_vi_handler(perf_intr + GIC_PIN_TO_VEC_OFFSET, gic_eic_irq_dispatch);
			gic_shared_intr_map[perf_intr + GIC_PIN_TO_VEC_OFFSET].local_intr_mask |= GIC_VPE_RMASK_PERFCNT_MSK;
		}
	}
}

unsigned int gic_compare_int(void)
{
	unsigned int pending;

	GICREAD(GIC_REG(VPE_LOCAL, GIC_VPE_PEND), pending);
	if (pending & GIC_VPE_PEND_CMP_MSK)
		return 1;
	else
		return 0;
}

unsigned int gic_get_int(void)
{
	unsigned int i;
	unsigned long *pending, *intrmask, *pcpu_mask;
	unsigned long *pending_abs, *intrmask_abs;

	/* Get per-cpu bitmaps */
	pending = pending_regs[smp_processor_id()].pending;
	intrmask = intrmask_regs[smp_processor_id()].intrmask;
	pcpu_mask = pcpu_masks[smp_processor_id()].pcpu_mask;

	pending_abs = (unsigned long *) GIC_REG_ABS_ADDR(SHARED,
							 GIC_SH_PEND_31_0_OFS);
	intrmask_abs = (unsigned long *) GIC_REG_ABS_ADDR(SHARED,
							  GIC_SH_MASK_31_0_OFS);

	for (i = 0; i < BITS_TO_LONGS(GIC_NUM_INTRS); i++) {
		GICREAD(*pending_abs, pending[i]);
		GICREAD(*intrmask_abs, intrmask[i]);
		pending_abs++;
		intrmask_abs++;
	}

	bitmap_and(pending, pending, intrmask, GIC_NUM_INTRS);
	bitmap_and(pending, pending, pcpu_mask, GIC_NUM_INTRS);

	return find_first_bit(pending, GIC_NUM_INTRS);
}

static void gic_mask_irq(struct irq_data *d)
{
	GIC_CLR_INTR_MASK(d->irq - gic_irq_base);
}

static void gic_unmask_irq(struct irq_data *d)
{
	GIC_SET_INTR_MASK(d->irq - gic_irq_base);
}

#ifdef CONFIG_SMP
static DEFINE_SPINLOCK(gic_lock);

static int gic_set_affinity(struct irq_data *d, const struct cpumask *cpumask,
			    bool force)
{
	unsigned int irq = (d->irq - gic_irq_base);
	cpumask_t	tmp = CPU_MASK_NONE;
	unsigned long	flags;
	int		i;

	cpumask_and(&tmp, cpumask, cpu_online_mask);
	if (cpus_empty(tmp))
		return -1;

	/* Assumption : cpumask refers to a single CPU */
	spin_lock_irqsave(&gic_lock, flags);
	for (;;) {
		/* Re-route this IRQ */
		GIC_SH_MAP_TO_VPE_SMASK(irq, first_cpu(tmp));

		/* Update the pcpu_masks */
		for (i = 0; i < NR_CPUS; i++)
			clear_bit(irq, pcpu_masks[i].pcpu_mask);
		set_bit(irq, pcpu_masks[first_cpu(tmp)].pcpu_mask);

	}
	cpumask_copy(d->affinity, cpumask);
	spin_unlock_irqrestore(&gic_lock, flags);

	return IRQ_SET_MASK_OK_NOCOPY;
}
#endif

static struct irq_chip gic_irq_controller = {
	.name			=	"MIPS GIC",
	.irq_ack		=	gic_irq_ack,
	.irq_mask		=	gic_mask_irq,
	.irq_mask_ack		=	gic_mask_irq,
	.irq_unmask		=	gic_unmask_irq,
	.irq_eoi		=	gic_finish_irq,
#ifdef CONFIG_SMP
	.irq_set_affinity	=	gic_set_affinity,
#endif
};

static void __init gic_setup_intr(unsigned int intr, unsigned int cpu,
	unsigned int pin, unsigned int polarity, unsigned int trigtype,
	unsigned int flags)
{
	struct gic_shared_intr_map *map_ptr;

	/* Setup Intr to Pin mapping */
	if (pin & GIC_MAP_TO_NMI_MSK) {
		GICWRITE(GIC_REG_ADDR(SHARED, GIC_SH_MAP_TO_PIN(intr)), pin);
		/* FIXME: hack to route NMI to all cpu's */
		for (cpu = 0; cpu < NR_CPUS; cpu += 32) {
			GICWRITE(GIC_REG_ADDR(SHARED,
					  GIC_SH_MAP_TO_VPE_REG_OFF(intr, cpu)),
				 0xffffffff);
		}
	} else {
		GICWRITE(GIC_REG_ADDR(SHARED, GIC_SH_MAP_TO_PIN(intr)),
			 GIC_MAP_TO_PIN_MSK | pin);
		/* Setup Intr to CPU mapping */
		GIC_SH_MAP_TO_VPE_SMASK(intr, cpu);
		if (cpu_has_veic) {
			set_vi_handler(pin + GIC_PIN_TO_VEC_OFFSET,
				gic_eic_irq_dispatch);
			map_ptr = &gic_shared_intr_map[pin + GIC_PIN_TO_VEC_OFFSET];
			if (map_ptr->num_shared_intr >= GIC_MAX_SHARED_INTR)
				BUG();
			map_ptr->intr_list[map_ptr->num_shared_intr++] = intr;
		}
	}

	/* Setup Intr Polarity */
	GIC_SET_POLARITY(intr, polarity);

	/* Setup Intr Trigger Type */
	GIC_SET_TRIGGER(intr, trigtype);

	/* Init Intr Masks */
	GIC_CLR_INTR_MASK(intr);
	/* Initialise per-cpu Interrupt software masks */
	if (flags & GIC_FLAG_IPI)
		set_bit(intr, pcpu_masks[cpu].pcpu_mask);
	if ((flags & GIC_FLAG_TRANSPARENT) && (cpu_has_veic == 0))
		GIC_SET_INTR_MASK(intr);
	if (trigtype == GIC_TRIG_EDGE)
		gic_irq_flags[intr] |= GIC_TRIG_EDGE;
}

static void __init gic_basic_init(int numintrs, int numvpes,
			struct gic_intr_map *intrmap, int mapsize)
{
	unsigned int i, cpu;
	unsigned int pin_offset = 0;

	board_bind_eic_interrupt = &gic_bind_eic_interrupt;

	/* Setup defaults */
	for (i = 0; i < numintrs; i++) {
		GIC_SET_POLARITY(i, GIC_POL_POS);
		GIC_SET_TRIGGER(i, GIC_TRIG_LEVEL);
		GIC_CLR_INTR_MASK(i);
		if (i < GIC_NUM_INTRS) {
			gic_irq_flags[i] = 0;
			gic_shared_intr_map[i].num_shared_intr = 0;
			gic_shared_intr_map[i].local_intr_mask = 0;
		}
	}

	/*
	 * In EIC mode, the HW_INT# is offset by (2-1). Need to subtract
	 * one because the GIC will add one (since 0=no intr).
	 */
	if (cpu_has_veic)
		pin_offset = (GIC_CPU_TO_VEC_OFFSET - GIC_PIN_TO_VEC_OFFSET);

	/* Setup specifics */
	for (i = 0; i < mapsize; i++) {
		cpu = intrmap[i].cpunum;
		if (cpu == GIC_UNUSED)
			continue;
		if (cpu == 0 && i != 0 && intrmap[i].flags == 0)
			continue;
		gic_setup_intr(i,
			intrmap[i].cpunum,
			intrmap[i].pin + pin_offset,
			intrmap[i].polarity,
			intrmap[i].trigtype,
			intrmap[i].flags);
	}

	vpe_local_setup(numvpes);
}

void __init gic_init(unsigned long gic_base_addr,
		     unsigned long gic_addrspace_size,
		     struct gic_intr_map *intr_map, unsigned int intr_map_size,
		     unsigned int irqbase)
{
	unsigned int gicconfig;
	int numvpes, numintrs;

	_gic_base = (unsigned long) ioremap_nocache(gic_base_addr,
						    gic_addrspace_size);
	gic_irq_base = irqbase;

	GICREAD(GIC_REG(SHARED, GIC_SH_CONFIG), gicconfig);
	numintrs = (gicconfig & GIC_SH_CONFIG_NUMINTRS_MSK) >>
		   GIC_SH_CONFIG_NUMINTRS_SHF;
	numintrs = ((numintrs + 1) * 8);

	numvpes = (gicconfig & GIC_SH_CONFIG_NUMVPES_MSK) >>
		  GIC_SH_CONFIG_NUMVPES_SHF;
	numvpes = numvpes + 1;

	gic_basic_init(numintrs, numvpes, intr_map, intr_map_size);

	gic_platform_init(numintrs, &gic_irq_controller);
}