xref: /openbmc/linux/arch/mips/sibyte/bcm1480/irq.c (revision 1ab142d4)
1 /*
2  * Copyright (C) 2000,2001,2002,2003,2004 Broadcom Corporation
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version 2
7  * of the License, or (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
17  */
18 #include <linux/kernel.h>
19 #include <linux/init.h>
20 #include <linux/linkage.h>
21 #include <linux/interrupt.h>
22 #include <linux/smp.h>
23 #include <linux/spinlock.h>
24 #include <linux/mm.h>
25 #include <linux/kernel_stat.h>
26 
27 #include <asm/errno.h>
28 #include <asm/irq_regs.h>
29 #include <asm/signal.h>
30 #include <asm/system.h>
31 #include <asm/io.h>
32 
33 #include <asm/sibyte/bcm1480_regs.h>
34 #include <asm/sibyte/bcm1480_int.h>
35 #include <asm/sibyte/bcm1480_scd.h>
36 
37 #include <asm/sibyte/sb1250_uart.h>
38 #include <asm/sibyte/sb1250.h>
39 
40 /*
41  * These are the routines that handle all the low level interrupt stuff.
42  * Actions handled here are: initialization of the interrupt map, requesting of
43  * interrupt lines by handlers, dispatching if interrupts to handlers, probing
44  * for interrupt lines
45  */
46 
47 #ifdef CONFIG_PCI
48 extern unsigned long ht_eoi_space;
49 #endif
50 
51 /* Store the CPU id (not the logical number) */
52 int bcm1480_irq_owner[BCM1480_NR_IRQS];
53 
54 static DEFINE_RAW_SPINLOCK(bcm1480_imr_lock);
55 
56 void bcm1480_mask_irq(int cpu, int irq)
57 {
58 	unsigned long flags, hl_spacing;
59 	u64 cur_ints;
60 
61 	raw_spin_lock_irqsave(&bcm1480_imr_lock, flags);
62 	hl_spacing = 0;
63 	if ((irq >= BCM1480_NR_IRQS_HALF) && (irq <= BCM1480_NR_IRQS)) {
64 		hl_spacing = BCM1480_IMR_HL_SPACING;
65 		irq -= BCM1480_NR_IRQS_HALF;
66 	}
67 	cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
68 	cur_ints |= (((u64) 1) << irq);
69 	____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
70 	raw_spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
71 }
72 
73 void bcm1480_unmask_irq(int cpu, int irq)
74 {
75 	unsigned long flags, hl_spacing;
76 	u64 cur_ints;
77 
78 	raw_spin_lock_irqsave(&bcm1480_imr_lock, flags);
79 	hl_spacing = 0;
80 	if ((irq >= BCM1480_NR_IRQS_HALF) && (irq <= BCM1480_NR_IRQS)) {
81 		hl_spacing = BCM1480_IMR_HL_SPACING;
82 		irq -= BCM1480_NR_IRQS_HALF;
83 	}
84 	cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
85 	cur_ints &= ~(((u64) 1) << irq);
86 	____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
87 	raw_spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
88 }
89 
90 #ifdef CONFIG_SMP
91 static int bcm1480_set_affinity(struct irq_data *d, const struct cpumask *mask,
92 				bool force)
93 {
94 	unsigned int irq_dirty, irq = d->irq;
95 	int i = 0, old_cpu, cpu, int_on, k;
96 	u64 cur_ints;
97 	unsigned long flags;
98 
99 	i = cpumask_first(mask);
100 
101 	/* Convert logical CPU to physical CPU */
102 	cpu = cpu_logical_map(i);
103 
104 	/* Protect against other affinity changers and IMR manipulation */
105 	raw_spin_lock_irqsave(&bcm1480_imr_lock, flags);
106 
107 	/* Swizzle each CPU's IMR (but leave the IP selection alone) */
108 	old_cpu = bcm1480_irq_owner[irq];
109 	irq_dirty = irq;
110 	if ((irq_dirty >= BCM1480_NR_IRQS_HALF) && (irq_dirty <= BCM1480_NR_IRQS)) {
111 		irq_dirty -= BCM1480_NR_IRQS_HALF;
112 	}
113 
114 	for (k=0; k<2; k++) { /* Loop through high and low interrupt mask register */
115 		cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(old_cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
116 		int_on = !(cur_ints & (((u64) 1) << irq_dirty));
117 		if (int_on) {
118 			/* If it was on, mask it */
119 			cur_ints |= (((u64) 1) << irq_dirty);
120 			____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(old_cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
121 		}
122 		bcm1480_irq_owner[irq] = cpu;
123 		if (int_on) {
124 			/* unmask for the new CPU */
125 			cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
126 			cur_ints &= ~(((u64) 1) << irq_dirty);
127 			____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
128 		}
129 	}
130 	raw_spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
131 
132 	return 0;
133 }
134 #endif
135 
136 
137 /*****************************************************************************/
138 
139 static void disable_bcm1480_irq(struct irq_data *d)
140 {
141 	unsigned int irq = d->irq;
142 
143 	bcm1480_mask_irq(bcm1480_irq_owner[irq], irq);
144 }
145 
146 static void enable_bcm1480_irq(struct irq_data *d)
147 {
148 	unsigned int irq = d->irq;
149 
150 	bcm1480_unmask_irq(bcm1480_irq_owner[irq], irq);
151 }
152 
153 
154 static void ack_bcm1480_irq(struct irq_data *d)
155 {
156 	unsigned int irq_dirty, irq = d->irq;
157 	u64 pending;
158 	int k;
159 
160 	/*
161 	 * If the interrupt was an HT interrupt, now is the time to
162 	 * clear it.  NOTE: we assume the HT bridge was set up to
163 	 * deliver the interrupts to all CPUs (which makes affinity
164 	 * changing easier for us)
165 	 */
166 	irq_dirty = irq;
167 	if ((irq_dirty >= BCM1480_NR_IRQS_HALF) && (irq_dirty <= BCM1480_NR_IRQS)) {
168 		irq_dirty -= BCM1480_NR_IRQS_HALF;
169 	}
170 	for (k=0; k<2; k++) { /* Loop through high and low LDT interrupts */
171 		pending = __raw_readq(IOADDR(A_BCM1480_IMR_REGISTER(bcm1480_irq_owner[irq],
172 						R_BCM1480_IMR_LDT_INTERRUPT_H + (k*BCM1480_IMR_HL_SPACING))));
173 		pending &= ((u64)1 << (irq_dirty));
174 		if (pending) {
175 #ifdef CONFIG_SMP
176 			int i;
177 			for (i=0; i<NR_CPUS; i++) {
178 				/*
179 				 * Clear for all CPUs so an affinity switch
180 				 * doesn't find an old status
181 				 */
182 				__raw_writeq(pending, IOADDR(A_BCM1480_IMR_REGISTER(cpu_logical_map(i),
183 								R_BCM1480_IMR_LDT_INTERRUPT_CLR_H + (k*BCM1480_IMR_HL_SPACING))));
184 			}
185 #else
186 			__raw_writeq(pending, IOADDR(A_BCM1480_IMR_REGISTER(0, R_BCM1480_IMR_LDT_INTERRUPT_CLR_H + (k*BCM1480_IMR_HL_SPACING))));
187 #endif
188 
189 			/*
190 			 * Generate EOI.  For Pass 1 parts, EOI is a nop.  For
191 			 * Pass 2, the LDT world may be edge-triggered, but
192 			 * this EOI shouldn't hurt.  If they are
193 			 * level-sensitive, the EOI is required.
194 			 */
195 #ifdef CONFIG_PCI
196 			if (ht_eoi_space)
197 				*(uint32_t *)(ht_eoi_space+(irq<<16)+(7<<2)) = 0;
198 #endif
199 		}
200 	}
201 	bcm1480_mask_irq(bcm1480_irq_owner[irq], irq);
202 }
203 
204 static struct irq_chip bcm1480_irq_type = {
205 	.name = "BCM1480-IMR",
206 	.irq_mask_ack = ack_bcm1480_irq,
207 	.irq_mask = disable_bcm1480_irq,
208 	.irq_unmask = enable_bcm1480_irq,
209 #ifdef CONFIG_SMP
210 	.irq_set_affinity = bcm1480_set_affinity
211 #endif
212 };
213 
214 void __init init_bcm1480_irqs(void)
215 {
216 	int i;
217 
218 	for (i = 0; i < BCM1480_NR_IRQS; i++) {
219 		irq_set_chip_and_handler(i, &bcm1480_irq_type,
220 					 handle_level_irq);
221 		bcm1480_irq_owner[i] = 0;
222 	}
223 }
224 
225 /*
226  *  init_IRQ is called early in the boot sequence from init/main.c.  It
227  *  is responsible for setting up the interrupt mapper and installing the
228  *  handler that will be responsible for dispatching interrupts to the
229  *  "right" place.
230  */
231 /*
232  * For now, map all interrupts to IP[2].  We could save
233  * some cycles by parceling out system interrupts to different
234  * IP lines, but keep it simple for bringup.  We'll also direct
235  * all interrupts to a single CPU; we should probably route
236  * PCI and LDT to one cpu and everything else to the other
237  * to balance the load a bit.
238  *
239  * On the second cpu, everything is set to IP5, which is
240  * ignored, EXCEPT the mailbox interrupt.  That one is
241  * set to IP[2] so it is handled.  This is needed so we
242  * can do cross-cpu function calls, as required by SMP
243  */
244 
245 #define IMR_IP2_VAL	K_BCM1480_INT_MAP_I0
246 #define IMR_IP3_VAL	K_BCM1480_INT_MAP_I1
247 #define IMR_IP4_VAL	K_BCM1480_INT_MAP_I2
248 #define IMR_IP5_VAL	K_BCM1480_INT_MAP_I3
249 #define IMR_IP6_VAL	K_BCM1480_INT_MAP_I4
250 
251 void __init arch_init_irq(void)
252 {
253 	unsigned int i, cpu;
254 	u64 tmp;
255 	unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
256 		STATUSF_IP1 | STATUSF_IP0;
257 
258 	/* Default everything to IP2 */
259 	/* Start with _high registers which has no bit 0 interrupt source */
260 	for (i = 1; i < BCM1480_NR_IRQS_HALF; i++) {	/* was I0 */
261 		for (cpu = 0; cpu < 4; cpu++) {
262 			__raw_writeq(IMR_IP2_VAL,
263 				     IOADDR(A_BCM1480_IMR_REGISTER(cpu,
264 								   R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) + (i << 3)));
265 		}
266 	}
267 
268 	/* Now do _low registers */
269 	for (i = 0; i < BCM1480_NR_IRQS_HALF; i++) {
270 		for (cpu = 0; cpu < 4; cpu++) {
271 			__raw_writeq(IMR_IP2_VAL,
272 				     IOADDR(A_BCM1480_IMR_REGISTER(cpu,
273 								   R_BCM1480_IMR_INTERRUPT_MAP_BASE_L) + (i << 3)));
274 		}
275 	}
276 
277 	init_bcm1480_irqs();
278 
279 	/*
280 	 * Map the high 16 bits of mailbox_0 registers to IP[3], for
281 	 * inter-cpu messages
282 	 */
283 	/* Was I1 */
284 	for (cpu = 0; cpu < 4; cpu++) {
285 		__raw_writeq(IMR_IP3_VAL, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) +
286 						 (K_BCM1480_INT_MBOX_0_0 << 3)));
287         }
288 
289 
290 	/* Clear the mailboxes.  The firmware may leave them dirty */
291 	for (cpu = 0; cpu < 4; cpu++) {
292 		__raw_writeq(0xffffffffffffffffULL,
293 			     IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_MAILBOX_0_CLR_CPU)));
294 		__raw_writeq(0xffffffffffffffffULL,
295 			     IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_MAILBOX_1_CLR_CPU)));
296 	}
297 
298 
299 	/* Mask everything except the high 16 bit of mailbox_0 registers for all cpus */
300 	tmp = ~((u64) 0) ^ ( (((u64) 1) << K_BCM1480_INT_MBOX_0_0));
301 	for (cpu = 0; cpu < 4; cpu++) {
302 		__raw_writeq(tmp, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MASK_H)));
303 	}
304 	tmp = ~((u64) 0);
305 	for (cpu = 0; cpu < 4; cpu++) {
306 		__raw_writeq(tmp, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MASK_L)));
307 	}
308 
309 	/*
310 	 * Note that the timer interrupts are also mapped, but this is
311 	 * done in bcm1480_time_init().  Also, the profiling driver
312 	 * does its own management of IP7.
313 	 */
314 
315 	/* Enable necessary IPs, disable the rest */
316 	change_c0_status(ST0_IM, imask);
317 }
318 
319 extern void bcm1480_mailbox_interrupt(void);
320 
321 static inline void dispatch_ip2(void)
322 {
323 	unsigned long long mask_h, mask_l;
324 	unsigned int cpu = smp_processor_id();
325 	unsigned long base;
326 
327 	/*
328 	 * Default...we've hit an IP[2] interrupt, which means we've got to
329 	 * check the 1480 interrupt registers to figure out what to do.  Need
330 	 * to detect which CPU we're on, now that smp_affinity is supported.
331 	 */
332 	base = A_BCM1480_IMR_MAPPER(cpu);
333 	mask_h = __raw_readq(
334 		IOADDR(base + R_BCM1480_IMR_INTERRUPT_STATUS_BASE_H));
335 	mask_l = __raw_readq(
336 		IOADDR(base + R_BCM1480_IMR_INTERRUPT_STATUS_BASE_L));
337 
338 	if (mask_h) {
339 		if (mask_h ^ 1)
340 			do_IRQ(fls64(mask_h) - 1);
341 		else if (mask_l)
342 			do_IRQ(63 + fls64(mask_l));
343 	}
344 }
345 
346 asmlinkage void plat_irq_dispatch(void)
347 {
348 	unsigned int cpu = smp_processor_id();
349 	unsigned int pending;
350 
351 #ifdef CONFIG_SIBYTE_BCM1480_PROF
352 	/* Set compare to count to silence count/compare timer interrupts */
353 	write_c0_compare(read_c0_count());
354 #endif
355 
356 	pending = read_c0_cause() & read_c0_status();
357 
358 #ifdef CONFIG_SIBYTE_BCM1480_PROF
359 	if (pending & CAUSEF_IP7)	/* Cpu performance counter interrupt */
360 		sbprof_cpu_intr();
361 	else
362 #endif
363 
364 	if (pending & CAUSEF_IP4)
365 		do_IRQ(K_BCM1480_INT_TIMER_0 + cpu);
366 #ifdef CONFIG_SMP
367 	else if (pending & CAUSEF_IP3)
368 		bcm1480_mailbox_interrupt();
369 #endif
370 
371 	else if (pending & CAUSEF_IP2)
372 		dispatch_ip2();
373 }
374