aboutsummaryrefslogtreecommitdiff
path: root/arch/mips/sibyte/sb1250/irq.c
blob: 5dae2ecb83ffde36f3e74eaa8fed389ea2567f9e (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
/*
 * Copyright (C) 2000, 2001, 2002, 2003 Broadcom Corporation
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/linkage.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/smp.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/kernel_stat.h>

#include <asm/errno.h>
#include <asm/signal.h>
#include <asm/system.h>
#include <asm/time.h>
#include <asm/io.h>

#include <asm/sibyte/sb1250_regs.h>
#include <asm/sibyte/sb1250_int.h>
#include <asm/sibyte/sb1250_uart.h>
#include <asm/sibyte/sb1250_scd.h>
#include <asm/sibyte/sb1250.h>

/*
 * These are the routines that handle all the low level interrupt stuff.
 * Actions handled here are: initialization of the interrupt map, requesting of
 * interrupt lines by handlers, dispatching if interrupts to handlers, probing
 * for interrupt lines
 */


static void end_sb1250_irq(unsigned int irq);
static void enable_sb1250_irq(unsigned int irq);
static void disable_sb1250_irq(unsigned int irq);
static void ack_sb1250_irq(unsigned int irq);
#ifdef CONFIG_SMP
static int sb1250_set_affinity(unsigned int irq, const struct cpumask *mask);
#endif

#ifdef CONFIG_SIBYTE_HAS_LDT
extern unsigned long ldt_eoi_space;
#endif

static struct irq_chip sb1250_irq_type = {
	.name = "SB1250-IMR",
	.ack = ack_sb1250_irq,
	.mask = disable_sb1250_irq,
	.mask_ack = ack_sb1250_irq,
	.unmask = enable_sb1250_irq,
	.end = end_sb1250_irq,
#ifdef CONFIG_SMP
	.set_affinity = sb1250_set_affinity
#endif
};

/* Store the CPU id (not the logical number) */
int sb1250_irq_owner[SB1250_NR_IRQS];

static DEFINE_SPINLOCK(sb1250_imr_lock);

void sb1250_mask_irq(int cpu, int irq)
{
	unsigned long flags;
	u64 cur_ints;

	spin_lock_irqsave(&sb1250_imr_lock, flags);
	cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(cpu) +
					R_IMR_INTERRUPT_MASK));
	cur_ints |= (((u64) 1) << irq);
	____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(cpu) +
					R_IMR_INTERRUPT_MASK));
	spin_unlock_irqrestore(&sb1250_imr_lock, flags);
}

void sb1250_unmask_irq(int cpu, int irq)
{
	unsigned long flags;
	u64 cur_ints;

	spin_lock_irqsave(&sb1250_imr_lock, flags);
	cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(cpu) +
					R_IMR_INTERRUPT_MASK));
	cur_ints &= ~(((u64) 1) << irq);
	____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(cpu) +
					R_IMR_INTERRUPT_MASK));
	spin_unlock_irqrestore(&sb1250_imr_lock, flags);
}

#ifdef CONFIG_SMP
static int sb1250_set_affinity(unsigned int irq, const struct cpumask *mask)
{
	int i = 0, old_cpu, cpu, int_on;
	u64 cur_ints;
	unsigned long flags;

	i = cpumask_first(mask);

	/* Convert logical CPU to physical CPU */
	cpu = cpu_logical_map(i);

	/* Protect against other affinity changers and IMR manipulation */
	spin_lock_irqsave(&sb1250_imr_lock, flags);

	/* Swizzle each CPU's IMR (but leave the IP selection alone) */
	old_cpu = sb1250_irq_owner[irq];
	cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(old_cpu) +
					R_IMR_INTERRUPT_MASK));
	int_on = !(cur_ints & (((u64) 1) << irq));
	if (int_on) {
		/* If it was on, mask it */
		cur_ints |= (((u64) 1) << irq);
		____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(old_cpu) +
					R_IMR_INTERRUPT_MASK));
	}
	sb1250_irq_owner[irq] = cpu;
	if (int_on) {
		/* unmask for the new CPU */
		cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(cpu) +
					R_IMR_INTERRUPT_MASK));
		cur_ints &= ~(((u64) 1) << irq);
		____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(cpu) +
					R_IMR_INTERRUPT_MASK));
	}
	spin_unlock_irqrestore(&sb1250_imr_lock, flags);

	return 0;
}
#endif

/*****************************************************************************/

static void disable_sb1250_irq(unsigned int irq)
{
	sb1250_mask_irq(sb1250_irq_owner[irq], irq);
}

static void enable_sb1250_irq(unsigned int irq)
{
	sb1250_unmask_irq(sb1250_irq_owner[irq], irq);
}


static void ack_sb1250_irq(unsigned int irq)
{
#ifdef CONFIG_SIBYTE_HAS_LDT
	u64 pending;

	/*
	 * If the interrupt was an HT interrupt, now is the time to
	 * clear it.  NOTE: we assume the HT bridge was set up to
	 * deliver the interrupts to all CPUs (which makes affinity
	 * changing easier for us)
	 */
	pending = __raw_readq(IOADDR(A_IMR_REGISTER(sb1250_irq_owner[irq],
						    R_IMR_LDT_INTERRUPT)));
	pending &= ((u64)1 << (irq));
	if (pending) {
		int i;
		for (i=0; i<NR_CPUS; i++) {
			int cpu;
#ifdef CONFIG_SMP
			cpu = cpu_logical_map(i);
#else
			cpu = i;
#endif
			/*
			 * Clear for all CPUs so an affinity switch
			 * doesn't find an old status
			 */
			__raw_writeq(pending,
				     IOADDR(A_IMR_REGISTER(cpu,
						R_IMR_LDT_INTERRUPT_CLR)));
		}

		/*
		 * Generate EOI.  For Pass 1 parts, EOI is a nop.  For
		 * Pass 2, the LDT world may be edge-triggered, but
		 * this EOI shouldn't hurt.  If they are
		 * level-sensitive, the EOI is required.
		 */
		*(uint32_t *)(ldt_eoi_space+(irq<<16)+(7<<2)) = 0;
	}
#endif
	sb1250_mask_irq(sb1250_irq_owner[irq], irq);
}


static void end_sb1250_irq(unsigned int irq)
{
	if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS))) {
		sb1250_unmask_irq(sb1250_irq_owner[irq], irq);
	}
}


void __init init_sb1250_irqs(void)
{
	int i;

	for (i = 0; i < SB1250_NR_IRQS; i++) {
		set_irq_chip_and_handler(i, &sb1250_irq_type, handle_level_irq);
		sb1250_irq_owner[i] = 0;
	}
}


/*
 *  arch_init_irq is called early in the boot sequence from init/main.c via
 *  init_IRQ.  It is responsible for setting up the interrupt mapper and
 *  installing the handler that will be responsible for dispatching interrupts
 *  to the "right" place.
 */
/*
 * For now, map all interrupts to IP[2].  We could save
 * some cycles by parceling out system interrupts to different
 * IP lines, but keep it simple for bringup.  We'll also direct
 * all interrupts to a single CPU; we should probably route
 * PCI and LDT to one cpu and everything else to the other
 * to balance the load a bit.
 *
 * On the second cpu, everything is set to IP5, which is
 * ignored, EXCEPT the mailbox interrupt.  That one is
 * set to IP[2] so it is handled.  This is needed so we
 * can do cross-cpu function calls, as requred by SMP
 */

#define IMR_IP2_VAL	K_INT_MAP_I0
#define IMR_IP3_VAL	K_INT_MAP_I1
#define IMR_IP4_VAL	K_INT_MAP_I2
#define IMR_IP5_VAL	K_INT_MAP_I3
#define IMR_IP6_VAL	K_INT_MAP_I4

void __init arch_init_irq(void)
{

	unsigned int i;
	u64 tmp;
	unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
		STATUSF_IP1 | STATUSF_IP0;

	/* Default everything to IP2 */
	for (i = 0; i < SB1250_NR_IRQS; i++) {	/* was I0 */
		__raw_writeq(IMR_IP2_VAL,
			     IOADDR(A_IMR_REGISTER(0,
						   R_IMR_INTERRUPT_MAP_BASE) +
				    (i << 3)));
		__raw_writeq(IMR_IP2_VAL,
			     IOADDR(A_IMR_REGISTER(1,
						   R_IMR_INTERRUPT_MAP_BASE) +
				    (i << 3)));
	}

	init_sb1250_irqs();

	/*
	 * Map the high 16 bits of the mailbox registers to IP[3], for
	 * inter-cpu messages
	 */
	/* Was I1 */
	__raw_writeq(IMR_IP3_VAL,
		     IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_MAP_BASE) +
			    (K_INT_MBOX_0 << 3)));
	__raw_writeq(IMR_IP3_VAL,
		     IOADDR(A_IMR_REGISTER(1, R_IMR_INTERRUPT_MAP_BASE) +
			    (K_INT_MBOX_0 << 3)));

	/* Clear the mailboxes.  The firmware may leave them dirty */
	__raw_writeq(0xffffffffffffffffULL,
		     IOADDR(A_IMR_REGISTER(0, R_IMR_MAILBOX_CLR_CPU)));
	__raw_writeq(0xffffffffffffffffULL,
		     IOADDR(A_IMR_REGISTER(1, R_IMR_MAILBOX_CLR_CPU)));

	/* Mask everything except the mailbox registers for both cpus */
	tmp = ~((u64) 0) ^ (((u64) 1) << K_INT_MBOX_0);
	__raw_writeq(tmp, IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_MASK)));
	__raw_writeq(tmp, IOADDR(A_IMR_REGISTER(1, R_IMR_INTERRUPT_MASK)));

	/*
	 * Note that the timer interrupts are also mapped, but this is
	 * done in sb1250_time_init().  Also, the profiling driver
	 * does its own management of IP7.
	 */

	/* Enable necessary IPs, disable the rest */
	change_c0_status(ST0_IM, imask);
}

extern void sb1250_mailbox_interrupt(void);

static inline void dispatch_ip2(void)
{
	unsigned int cpu = smp_processor_id();
	unsigned long long mask;

	/*
	 * Default...we've hit an IP[2] interrupt, which means we've got to
	 * check the 1250 interrupt registers to figure out what to do.  Need
	 * to detect which CPU we're on, now that smp_affinity is supported.
	 */
	mask = __raw_readq(IOADDR(A_IMR_REGISTER(cpu,
				  R_IMR_INTERRUPT_STATUS_BASE)));
	if (mask)
		do_IRQ(fls64(mask) - 1);
}

asmlinkage void plat_irq_dispatch(void)
{
	unsigned int cpu = smp_processor_id();
	unsigned int pending;

	/*
	 * What a pain. We have to be really careful saving the upper 32 bits
	 * of any * register across function calls if we don't want them
	 * trashed--since were running in -o32, the calling routing never saves
	 * the full 64 bits of a register across a function call.  Being the
	 * interrupt handler, we're guaranteed that interrupts are disabled
	 * during this code so we don't have to worry about random interrupts
	 * blasting the high 32 bits.
	 */

	pending = read_c0_cause() & read_c0_status() & ST0_IM;

	if (pending & CAUSEF_IP7) /* CPU performance counter interrupt */
		do_IRQ(MIPS_CPU_IRQ_BASE + 7);
	else if (pending & CAUSEF_IP4)
		do_IRQ(K_INT_TIMER_0 + cpu); 	/* sb1250_timer_interrupt() */

#ifdef CONFIG_SMP
	else if (pending & CAUSEF_IP3)
		sb1250_mailbox_interrupt();
#endif

	else if (pending & CAUSEF_IP2)
		dispatch_ip2();
	else
		spurious_interrupt();
}