summaryrefslogtreecommitdiff
path: root/arch/mips/kernel/irq-gic.c
blob: 3f43c2e3aa5a59ede8eab7ecdaee7762ea6afb68 (plain) (blame)
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
#undef DEBUG

#include <linux/bitmap.h>
#include <linux/init.h>

#include <asm/io.h>
#include <asm/gic.h>
#include <asm/gcmpregs.h>
#include <asm/mips-boards/maltaint.h>
#include <asm/irq.h>
#include <linux/hardirq.h>
#include <asm-generic/bitops/find.h>


static unsigned long _gic_base;
static unsigned int _irqbase, _mapsize, numvpes, numintrs;
static struct gic_intr_map *_intrmap;

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];

#define gic_wedgeb2bok 0	/*
				 * Can GIC handle b2b writes to wedge register?
				 */
#if gic_wedgeb2bok == 0
static DEFINE_SPINLOCK(gic_wedgeb2b_lock);
#endif

void gic_send_ipi(unsigned int intr)
{
#if gic_wedgeb2bok == 0
	unsigned long flags;
#endif
	pr_debug("CPU%d: %s status %08x\n", smp_processor_id(), __func__,
		 read_c0_status());
	if (!gic_wedgeb2bok)
		spin_lock_irqsave(&gic_wedgeb2b_lock, flags);
	GICWRITE(GIC_REG(SHARED, GIC_SH_WEDGE), 0x80000000 | intr);
	if (!gic_wedgeb2bok) {
		(void) GIC_REG(SHARED, GIC_SH_CONFIG);
		spin_unlock_irqrestore(&gic_wedgeb2b_lock, flags);
	}
}

/* This is Malta specific and needs to be exported */
static void vpe_local_setup(unsigned int numvpes)
{
	int i;
	unsigned long timer_interrupt = 5, perf_interrupt = 5;
	unsigned int vpe_ctl;

	/*
	 * 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_interrupt);

		if (vpe_ctl & GIC_VPE_CTL_PERFCNT_RTBL_MSK)
			GICWRITE(GIC_REG(VPE_OTHER, GIC_VPE_PERFCTR_MAP),
				 GIC_MAP_TO_PIN_MSK | perf_interrupt);
	}
}

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);

	i = find_first_bit(pending, GIC_NUM_INTRS);

	pr_debug("CPU%d: %s pend=%d\n", smp_processor_id(), __func__, i);

	return i;
}

static unsigned int gic_irq_startup(unsigned int irq)
{
	pr_debug("CPU%d: %s: irq%d\n", smp_processor_id(), __func__, irq);
	irq -= _irqbase;
	/* FIXME: this is wrong for !GICISWORDLITTLEENDIAN */
	GICWRITE(GIC_REG_ADDR(SHARED, (GIC_SH_SMASK_31_0_OFS + (irq / 32))),
		 1 << (irq % 32));
	return 0;
}

static void gic_irq_ack(unsigned int irq)
{
#if gic_wedgeb2bok == 0
	unsigned long flags;
#endif
	pr_debug("CPU%d: %s: irq%d\n", smp_processor_id(), __func__, irq);
	irq -= _irqbase;
	GICWRITE(GIC_REG_ADDR(SHARED, (GIC_SH_RMASK_31_0_OFS + (irq / 32))),
		 1 << (irq % 32));

	if (_intrmap[irq].trigtype == GIC_TRIG_EDGE) {
		if (!gic_wedgeb2bok)
			spin_lock_irqsave(&gic_wedgeb2b_lock, flags);
		GICWRITE(GIC_REG(SHARED, GIC_SH_WEDGE), irq);
		if (!gic_wedgeb2bok) {
			(void) GIC_REG(SHARED, GIC_SH_CONFIG);
			spin_unlock_irqrestore(&gic_wedgeb2b_lock, flags);
		}
	}
}

static void gic_mask_irq(unsigned int irq)
{
	pr_debug("CPU%d: %s: irq%d\n", smp_processor_id(), __func__, irq);
	irq -= _irqbase;
	/* FIXME: this is wrong for !GICISWORDLITTLEENDIAN */
	GICWRITE(GIC_REG_ADDR(SHARED, (GIC_SH_RMASK_31_0_OFS + (irq / 32))),
		 1 << (irq % 32));
}

static void gic_unmask_irq(unsigned int irq)
{
	pr_debug("CPU%d: %s: irq%d\n", smp_processor_id(), __func__, irq);
	irq -= _irqbase;
	/* FIXME: this is wrong for !GICISWORDLITTLEENDIAN */
	GICWRITE(GIC_REG_ADDR(SHARED, (GIC_SH_SMASK_31_0_OFS + (irq / 32))),
		 1 << (irq % 32));
}

#ifdef CONFIG_SMP

static DEFINE_SPINLOCK(gic_lock);

static int gic_set_affinity(unsigned int irq, const struct cpumask *cpumask)
{
	cpumask_t	tmp = CPU_MASK_NONE;
	unsigned long	flags;
	int		i;

	pr_debug(KERN_DEBUG "%s called\n", __func__);
	irq -= _irqbase;

	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));

		/*
		 * FIXME: assumption that _intrmap is ordered and has no holes
		 */

		/* Update the intr_map */
		_intrmap[irq].cpunum = 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(irq_desc[irq].affinity, cpumask);
	spin_unlock_irqrestore(&gic_lock, flags);

	return 0;
}
#endif

static struct irq_chip gic_irq_controller = {
	.name		=	"MIPS GIC",
	.startup	=	gic_irq_startup,
	.ack		=	gic_irq_ack,
	.mask		=	gic_mask_irq,
	.mask_ack	=	gic_mask_irq,
	.unmask		=	gic_unmask_irq,
	.eoi		=	gic_unmask_irq,
#ifdef CONFIG_SMP
	.set_affinity	=	gic_set_affinity,
#endif
};

static void __init setup_intr(unsigned int intr, unsigned int cpu,
	unsigned int pin, unsigned int polarity, unsigned int trigtype)
{
	/* 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);
	}

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

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

	/* Init Intr Masks */
	GIC_SET_INTR_MASK(intr, 0);
}

static void __init gic_basic_init(void)
{
	unsigned int i, cpu;

	/* Setup defaults */
	for (i = 0; i < GIC_NUM_INTRS; i++) {
		GIC_SET_POLARITY(i, GIC_POL_POS);
		GIC_SET_TRIGGER(i, GIC_TRIG_LEVEL);
		GIC_SET_INTR_MASK(i, 0);
	}

	/* Setup specifics */
	for (i = 0; i < _mapsize; i++) {
		cpu = _intrmap[i].cpunum;
		if (cpu == X)
			continue;

		setup_intr(_intrmap[i].intrnum,
				_intrmap[i].cpunum,
				_intrmap[i].pin,
				_intrmap[i].polarity,
				_intrmap[i].trigtype);
		/* Initialise per-cpu Interrupt software masks */
		if (_intrmap[i].ipiflag)
			set_bit(_intrmap[i].intrnum, pcpu_masks[cpu].pcpu_mask);
	}

	vpe_local_setup(numvpes);

	for (i = _irqbase; i < (_irqbase + numintrs); i++)
		set_irq_chip(i, &gic_irq_controller);
}

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;

	_gic_base = (unsigned long) ioremap_nocache(gic_base_addr,
						    gic_addrspace_size);
	_irqbase = irqbase;
	_intrmap = intr_map;
	_mapsize = intr_map_size;

	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;

	pr_debug("%s called\n", __func__);

	gic_basic_init();
}