xref: /openbmc/linux/arch/mips/sibyte/bcm1480/irq.c (revision 1fa6ac37)
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 
48 static void end_bcm1480_irq(unsigned int irq);
49 static void enable_bcm1480_irq(unsigned int irq);
50 static void disable_bcm1480_irq(unsigned int irq);
51 static void ack_bcm1480_irq(unsigned int irq);
52 #ifdef CONFIG_SMP
53 static int bcm1480_set_affinity(unsigned int irq, const struct cpumask *mask);
54 #endif
55 
56 #ifdef CONFIG_PCI
57 extern unsigned long ht_eoi_space;
58 #endif
59 
60 static struct irq_chip bcm1480_irq_type = {
61 	.name = "BCM1480-IMR",
62 	.ack = ack_bcm1480_irq,
63 	.mask = disable_bcm1480_irq,
64 	.mask_ack = ack_bcm1480_irq,
65 	.unmask = enable_bcm1480_irq,
66 	.end = end_bcm1480_irq,
67 #ifdef CONFIG_SMP
68 	.set_affinity = bcm1480_set_affinity
69 #endif
70 };
71 
72 /* Store the CPU id (not the logical number) */
73 int bcm1480_irq_owner[BCM1480_NR_IRQS];
74 
75 static DEFINE_RAW_SPINLOCK(bcm1480_imr_lock);
76 
77 void bcm1480_mask_irq(int cpu, int irq)
78 {
79 	unsigned long flags, hl_spacing;
80 	u64 cur_ints;
81 
82 	raw_spin_lock_irqsave(&bcm1480_imr_lock, flags);
83 	hl_spacing = 0;
84 	if ((irq >= BCM1480_NR_IRQS_HALF) && (irq <= BCM1480_NR_IRQS)) {
85 		hl_spacing = BCM1480_IMR_HL_SPACING;
86 		irq -= BCM1480_NR_IRQS_HALF;
87 	}
88 	cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
89 	cur_ints |= (((u64) 1) << irq);
90 	____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
91 	raw_spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
92 }
93 
94 void bcm1480_unmask_irq(int cpu, int irq)
95 {
96 	unsigned long flags, hl_spacing;
97 	u64 cur_ints;
98 
99 	raw_spin_lock_irqsave(&bcm1480_imr_lock, flags);
100 	hl_spacing = 0;
101 	if ((irq >= BCM1480_NR_IRQS_HALF) && (irq <= BCM1480_NR_IRQS)) {
102 		hl_spacing = BCM1480_IMR_HL_SPACING;
103 		irq -= BCM1480_NR_IRQS_HALF;
104 	}
105 	cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
106 	cur_ints &= ~(((u64) 1) << irq);
107 	____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
108 	raw_spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
109 }
110 
111 #ifdef CONFIG_SMP
112 static int bcm1480_set_affinity(unsigned int irq, const struct cpumask *mask)
113 {
114 	int i = 0, old_cpu, cpu, int_on, k;
115 	u64 cur_ints;
116 	unsigned long flags;
117 	unsigned int irq_dirty;
118 
119 	i = cpumask_first(mask);
120 
121 	/* Convert logical CPU to physical CPU */
122 	cpu = cpu_logical_map(i);
123 
124 	/* Protect against other affinity changers and IMR manipulation */
125 	raw_spin_lock_irqsave(&bcm1480_imr_lock, flags);
126 
127 	/* Swizzle each CPU's IMR (but leave the IP selection alone) */
128 	old_cpu = bcm1480_irq_owner[irq];
129 	irq_dirty = irq;
130 	if ((irq_dirty >= BCM1480_NR_IRQS_HALF) && (irq_dirty <= BCM1480_NR_IRQS)) {
131 		irq_dirty -= BCM1480_NR_IRQS_HALF;
132 	}
133 
134 	for (k=0; k<2; k++) { /* Loop through high and low interrupt mask register */
135 		cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(old_cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
136 		int_on = !(cur_ints & (((u64) 1) << irq_dirty));
137 		if (int_on) {
138 			/* If it was on, mask it */
139 			cur_ints |= (((u64) 1) << irq_dirty);
140 			____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(old_cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
141 		}
142 		bcm1480_irq_owner[irq] = cpu;
143 		if (int_on) {
144 			/* unmask for the new CPU */
145 			cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
146 			cur_ints &= ~(((u64) 1) << irq_dirty);
147 			____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
148 		}
149 	}
150 	raw_spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
151 
152 	return 0;
153 }
154 #endif
155 
156 
157 /*****************************************************************************/
158 
159 static void disable_bcm1480_irq(unsigned int irq)
160 {
161 	bcm1480_mask_irq(bcm1480_irq_owner[irq], irq);
162 }
163 
164 static void enable_bcm1480_irq(unsigned int irq)
165 {
166 	bcm1480_unmask_irq(bcm1480_irq_owner[irq], irq);
167 }
168 
169 
170 static void ack_bcm1480_irq(unsigned int irq)
171 {
172 	u64 pending;
173 	unsigned int irq_dirty;
174 	int k;
175 
176 	/*
177 	 * If the interrupt was an HT interrupt, now is the time to
178 	 * clear it.  NOTE: we assume the HT bridge was set up to
179 	 * deliver the interrupts to all CPUs (which makes affinity
180 	 * changing easier for us)
181 	 */
182 	irq_dirty = irq;
183 	if ((irq_dirty >= BCM1480_NR_IRQS_HALF) && (irq_dirty <= BCM1480_NR_IRQS)) {
184 		irq_dirty -= BCM1480_NR_IRQS_HALF;
185 	}
186 	for (k=0; k<2; k++) { /* Loop through high and low LDT interrupts */
187 		pending = __raw_readq(IOADDR(A_BCM1480_IMR_REGISTER(bcm1480_irq_owner[irq],
188 						R_BCM1480_IMR_LDT_INTERRUPT_H + (k*BCM1480_IMR_HL_SPACING))));
189 		pending &= ((u64)1 << (irq_dirty));
190 		if (pending) {
191 #ifdef CONFIG_SMP
192 			int i;
193 			for (i=0; i<NR_CPUS; i++) {
194 				/*
195 				 * Clear for all CPUs so an affinity switch
196 				 * doesn't find an old status
197 				 */
198 				__raw_writeq(pending, IOADDR(A_BCM1480_IMR_REGISTER(cpu_logical_map(i),
199 								R_BCM1480_IMR_LDT_INTERRUPT_CLR_H + (k*BCM1480_IMR_HL_SPACING))));
200 			}
201 #else
202 			__raw_writeq(pending, IOADDR(A_BCM1480_IMR_REGISTER(0, R_BCM1480_IMR_LDT_INTERRUPT_CLR_H + (k*BCM1480_IMR_HL_SPACING))));
203 #endif
204 
205 			/*
206 			 * Generate EOI.  For Pass 1 parts, EOI is a nop.  For
207 			 * Pass 2, the LDT world may be edge-triggered, but
208 			 * this EOI shouldn't hurt.  If they are
209 			 * level-sensitive, the EOI is required.
210 			 */
211 #ifdef CONFIG_PCI
212 			if (ht_eoi_space)
213 				*(uint32_t *)(ht_eoi_space+(irq<<16)+(7<<2)) = 0;
214 #endif
215 		}
216 	}
217 	bcm1480_mask_irq(bcm1480_irq_owner[irq], irq);
218 }
219 
220 
221 static void end_bcm1480_irq(unsigned int irq)
222 {
223 	if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS))) {
224 		bcm1480_unmask_irq(bcm1480_irq_owner[irq], irq);
225 	}
226 }
227 
228 
229 void __init init_bcm1480_irqs(void)
230 {
231 	int i;
232 
233 	for (i = 0; i < BCM1480_NR_IRQS; i++) {
234 		set_irq_chip_and_handler(i, &bcm1480_irq_type, handle_level_irq);
235 		bcm1480_irq_owner[i] = 0;
236 	}
237 }
238 
239 /*
240  *  init_IRQ is called early in the boot sequence from init/main.c.  It
241  *  is responsible for setting up the interrupt mapper and installing the
242  *  handler that will be responsible for dispatching interrupts to the
243  *  "right" place.
244  */
245 /*
246  * For now, map all interrupts to IP[2].  We could save
247  * some cycles by parceling out system interrupts to different
248  * IP lines, but keep it simple for bringup.  We'll also direct
249  * all interrupts to a single CPU; we should probably route
250  * PCI and LDT to one cpu and everything else to the other
251  * to balance the load a bit.
252  *
253  * On the second cpu, everything is set to IP5, which is
254  * ignored, EXCEPT the mailbox interrupt.  That one is
255  * set to IP[2] so it is handled.  This is needed so we
256  * can do cross-cpu function calls, as required by SMP
257  */
258 
259 #define IMR_IP2_VAL	K_BCM1480_INT_MAP_I0
260 #define IMR_IP3_VAL	K_BCM1480_INT_MAP_I1
261 #define IMR_IP4_VAL	K_BCM1480_INT_MAP_I2
262 #define IMR_IP5_VAL	K_BCM1480_INT_MAP_I3
263 #define IMR_IP6_VAL	K_BCM1480_INT_MAP_I4
264 
265 void __init arch_init_irq(void)
266 {
267 	unsigned int i, cpu;
268 	u64 tmp;
269 	unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
270 		STATUSF_IP1 | STATUSF_IP0;
271 
272 	/* Default everything to IP2 */
273 	/* Start with _high registers which has no bit 0 interrupt source */
274 	for (i = 1; i < BCM1480_NR_IRQS_HALF; i++) {	/* was I0 */
275 		for (cpu = 0; cpu < 4; cpu++) {
276 			__raw_writeq(IMR_IP2_VAL,
277 				     IOADDR(A_BCM1480_IMR_REGISTER(cpu,
278 								   R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) + (i << 3)));
279 		}
280 	}
281 
282 	/* Now do _low registers */
283 	for (i = 0; i < BCM1480_NR_IRQS_HALF; i++) {
284 		for (cpu = 0; cpu < 4; cpu++) {
285 			__raw_writeq(IMR_IP2_VAL,
286 				     IOADDR(A_BCM1480_IMR_REGISTER(cpu,
287 								   R_BCM1480_IMR_INTERRUPT_MAP_BASE_L) + (i << 3)));
288 		}
289 	}
290 
291 	init_bcm1480_irqs();
292 
293 	/*
294 	 * Map the high 16 bits of mailbox_0 registers to IP[3], for
295 	 * inter-cpu messages
296 	 */
297 	/* Was I1 */
298 	for (cpu = 0; cpu < 4; cpu++) {
299 		__raw_writeq(IMR_IP3_VAL, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) +
300 						 (K_BCM1480_INT_MBOX_0_0 << 3)));
301         }
302 
303 
304 	/* Clear the mailboxes.  The firmware may leave them dirty */
305 	for (cpu = 0; cpu < 4; cpu++) {
306 		__raw_writeq(0xffffffffffffffffULL,
307 			     IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_MAILBOX_0_CLR_CPU)));
308 		__raw_writeq(0xffffffffffffffffULL,
309 			     IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_MAILBOX_1_CLR_CPU)));
310 	}
311 
312 
313 	/* Mask everything except the high 16 bit of mailbox_0 registers for all cpus */
314 	tmp = ~((u64) 0) ^ ( (((u64) 1) << K_BCM1480_INT_MBOX_0_0));
315 	for (cpu = 0; cpu < 4; cpu++) {
316 		__raw_writeq(tmp, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MASK_H)));
317 	}
318 	tmp = ~((u64) 0);
319 	for (cpu = 0; cpu < 4; cpu++) {
320 		__raw_writeq(tmp, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MASK_L)));
321 	}
322 
323 	/*
324 	 * Note that the timer interrupts are also mapped, but this is
325 	 * done in bcm1480_time_init().  Also, the profiling driver
326 	 * does its own management of IP7.
327 	 */
328 
329 	/* Enable necessary IPs, disable the rest */
330 	change_c0_status(ST0_IM, imask);
331 }
332 
333 extern void bcm1480_mailbox_interrupt(void);
334 
335 static inline void dispatch_ip2(void)
336 {
337 	unsigned long long mask_h, mask_l;
338 	unsigned int cpu = smp_processor_id();
339 	unsigned long base;
340 
341 	/*
342 	 * Default...we've hit an IP[2] interrupt, which means we've got to
343 	 * check the 1480 interrupt registers to figure out what to do.  Need
344 	 * to detect which CPU we're on, now that smp_affinity is supported.
345 	 */
346 	base = A_BCM1480_IMR_MAPPER(cpu);
347 	mask_h = __raw_readq(
348 		IOADDR(base + R_BCM1480_IMR_INTERRUPT_STATUS_BASE_H));
349 	mask_l = __raw_readq(
350 		IOADDR(base + R_BCM1480_IMR_INTERRUPT_STATUS_BASE_L));
351 
352 	if (mask_h) {
353 		if (mask_h ^ 1)
354 			do_IRQ(fls64(mask_h) - 1);
355 		else if (mask_l)
356 			do_IRQ(63 + fls64(mask_l));
357 	}
358 }
359 
360 asmlinkage void plat_irq_dispatch(void)
361 {
362 	unsigned int cpu = smp_processor_id();
363 	unsigned int pending;
364 
365 #ifdef CONFIG_SIBYTE_BCM1480_PROF
366 	/* Set compare to count to silence count/compare timer interrupts */
367 	write_c0_compare(read_c0_count());
368 #endif
369 
370 	pending = read_c0_cause() & read_c0_status();
371 
372 #ifdef CONFIG_SIBYTE_BCM1480_PROF
373 	if (pending & CAUSEF_IP7)	/* Cpu performance counter interrupt */
374 		sbprof_cpu_intr();
375 	else
376 #endif
377 
378 	if (pending & CAUSEF_IP4)
379 		do_IRQ(K_BCM1480_INT_TIMER_0 + cpu);
380 #ifdef CONFIG_SMP
381 	else if (pending & CAUSEF_IP3)
382 		bcm1480_mailbox_interrupt();
383 #endif
384 
385 	else if (pending & CAUSEF_IP2)
386 		dispatch_ip2();
387 }
388