xref: /openbmc/linux/arch/mips/sibyte/bcm1480/irq.c (revision fea88a0c)
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/io.h>
31 
32 #include <asm/sibyte/bcm1480_regs.h>
33 #include <asm/sibyte/bcm1480_int.h>
34 #include <asm/sibyte/bcm1480_scd.h>
35 
36 #include <asm/sibyte/sb1250_uart.h>
37 #include <asm/sibyte/sb1250.h>
38 
39 /*
40  * These are the routines that handle all the low level interrupt stuff.
41  * Actions handled here are: initialization of the interrupt map, requesting of
42  * interrupt lines by handlers, dispatching if interrupts to handlers, probing
43  * for interrupt lines
44  */
45 
46 #ifdef CONFIG_PCI
47 extern unsigned long ht_eoi_space;
48 #endif
49 
50 /* Store the CPU id (not the logical number) */
51 int bcm1480_irq_owner[BCM1480_NR_IRQS];
52 
53 static DEFINE_RAW_SPINLOCK(bcm1480_imr_lock);
54 
55 void bcm1480_mask_irq(int cpu, int irq)
56 {
57 	unsigned long flags, hl_spacing;
58 	u64 cur_ints;
59 
60 	raw_spin_lock_irqsave(&bcm1480_imr_lock, flags);
61 	hl_spacing = 0;
62 	if ((irq >= BCM1480_NR_IRQS_HALF) && (irq <= BCM1480_NR_IRQS)) {
63 		hl_spacing = BCM1480_IMR_HL_SPACING;
64 		irq -= BCM1480_NR_IRQS_HALF;
65 	}
66 	cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
67 	cur_ints |= (((u64) 1) << irq);
68 	____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
69 	raw_spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
70 }
71 
72 void bcm1480_unmask_irq(int cpu, int irq)
73 {
74 	unsigned long flags, hl_spacing;
75 	u64 cur_ints;
76 
77 	raw_spin_lock_irqsave(&bcm1480_imr_lock, flags);
78 	hl_spacing = 0;
79 	if ((irq >= BCM1480_NR_IRQS_HALF) && (irq <= BCM1480_NR_IRQS)) {
80 		hl_spacing = BCM1480_IMR_HL_SPACING;
81 		irq -= BCM1480_NR_IRQS_HALF;
82 	}
83 	cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
84 	cur_ints &= ~(((u64) 1) << irq);
85 	____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
86 	raw_spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
87 }
88 
89 #ifdef CONFIG_SMP
90 static int bcm1480_set_affinity(struct irq_data *d, const struct cpumask *mask,
91 				bool force)
92 {
93 	unsigned int irq_dirty, irq = d->irq;
94 	int i = 0, old_cpu, cpu, int_on, k;
95 	u64 cur_ints;
96 	unsigned long flags;
97 
98 	i = cpumask_first(mask);
99 
100 	/* Convert logical CPU to physical CPU */
101 	cpu = cpu_logical_map(i);
102 
103 	/* Protect against other affinity changers and IMR manipulation */
104 	raw_spin_lock_irqsave(&bcm1480_imr_lock, flags);
105 
106 	/* Swizzle each CPU's IMR (but leave the IP selection alone) */
107 	old_cpu = bcm1480_irq_owner[irq];
108 	irq_dirty = irq;
109 	if ((irq_dirty >= BCM1480_NR_IRQS_HALF) && (irq_dirty <= BCM1480_NR_IRQS)) {
110 		irq_dirty -= BCM1480_NR_IRQS_HALF;
111 	}
112 
113 	for (k=0; k<2; k++) { /* Loop through high and low interrupt mask register */
114 		cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(old_cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
115 		int_on = !(cur_ints & (((u64) 1) << irq_dirty));
116 		if (int_on) {
117 			/* If it was on, mask it */
118 			cur_ints |= (((u64) 1) << irq_dirty);
119 			____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(old_cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
120 		}
121 		bcm1480_irq_owner[irq] = cpu;
122 		if (int_on) {
123 			/* unmask for the new CPU */
124 			cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
125 			cur_ints &= ~(((u64) 1) << irq_dirty);
126 			____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
127 		}
128 	}
129 	raw_spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
130 
131 	return 0;
132 }
133 #endif
134 
135 
136 /*****************************************************************************/
137 
138 static void disable_bcm1480_irq(struct irq_data *d)
139 {
140 	unsigned int irq = d->irq;
141 
142 	bcm1480_mask_irq(bcm1480_irq_owner[irq], irq);
143 }
144 
145 static void enable_bcm1480_irq(struct irq_data *d)
146 {
147 	unsigned int irq = d->irq;
148 
149 	bcm1480_unmask_irq(bcm1480_irq_owner[irq], irq);
150 }
151 
152 
153 static void ack_bcm1480_irq(struct irq_data *d)
154 {
155 	unsigned int irq_dirty, irq = d->irq;
156 	u64 pending;
157 	int k;
158 
159 	/*
160 	 * If the interrupt was an HT interrupt, now is the time to
161 	 * clear it.  NOTE: we assume the HT bridge was set up to
162 	 * deliver the interrupts to all CPUs (which makes affinity
163 	 * changing easier for us)
164 	 */
165 	irq_dirty = irq;
166 	if ((irq_dirty >= BCM1480_NR_IRQS_HALF) && (irq_dirty <= BCM1480_NR_IRQS)) {
167 		irq_dirty -= BCM1480_NR_IRQS_HALF;
168 	}
169 	for (k=0; k<2; k++) { /* Loop through high and low LDT interrupts */
170 		pending = __raw_readq(IOADDR(A_BCM1480_IMR_REGISTER(bcm1480_irq_owner[irq],
171 						R_BCM1480_IMR_LDT_INTERRUPT_H + (k*BCM1480_IMR_HL_SPACING))));
172 		pending &= ((u64)1 << (irq_dirty));
173 		if (pending) {
174 #ifdef CONFIG_SMP
175 			int i;
176 			for (i=0; i<NR_CPUS; i++) {
177 				/*
178 				 * Clear for all CPUs so an affinity switch
179 				 * doesn't find an old status
180 				 */
181 				__raw_writeq(pending, IOADDR(A_BCM1480_IMR_REGISTER(cpu_logical_map(i),
182 								R_BCM1480_IMR_LDT_INTERRUPT_CLR_H + (k*BCM1480_IMR_HL_SPACING))));
183 			}
184 #else
185 			__raw_writeq(pending, IOADDR(A_BCM1480_IMR_REGISTER(0, R_BCM1480_IMR_LDT_INTERRUPT_CLR_H + (k*BCM1480_IMR_HL_SPACING))));
186 #endif
187 
188 			/*
189 			 * Generate EOI.  For Pass 1 parts, EOI is a nop.  For
190 			 * Pass 2, the LDT world may be edge-triggered, but
191 			 * this EOI shouldn't hurt.  If they are
192 			 * level-sensitive, the EOI is required.
193 			 */
194 #ifdef CONFIG_PCI
195 			if (ht_eoi_space)
196 				*(uint32_t *)(ht_eoi_space+(irq<<16)+(7<<2)) = 0;
197 #endif
198 		}
199 	}
200 	bcm1480_mask_irq(bcm1480_irq_owner[irq], irq);
201 }
202 
203 static struct irq_chip bcm1480_irq_type = {
204 	.name = "BCM1480-IMR",
205 	.irq_mask_ack = ack_bcm1480_irq,
206 	.irq_mask = disable_bcm1480_irq,
207 	.irq_unmask = enable_bcm1480_irq,
208 #ifdef CONFIG_SMP
209 	.irq_set_affinity = bcm1480_set_affinity
210 #endif
211 };
212 
213 void __init init_bcm1480_irqs(void)
214 {
215 	int i;
216 
217 	for (i = 0; i < BCM1480_NR_IRQS; i++) {
218 		irq_set_chip_and_handler(i, &bcm1480_irq_type,
219 					 handle_level_irq);
220 		bcm1480_irq_owner[i] = 0;
221 	}
222 }
223 
224 /*
225  *  init_IRQ is called early in the boot sequence from init/main.c.  It
226  *  is responsible for setting up the interrupt mapper and installing the
227  *  handler that will be responsible for dispatching interrupts to the
228  *  "right" place.
229  */
230 /*
231  * For now, map all interrupts to IP[2].  We could save
232  * some cycles by parceling out system interrupts to different
233  * IP lines, but keep it simple for bringup.  We'll also direct
234  * all interrupts to a single CPU; we should probably route
235  * PCI and LDT to one cpu and everything else to the other
236  * to balance the load a bit.
237  *
238  * On the second cpu, everything is set to IP5, which is
239  * ignored, EXCEPT the mailbox interrupt.  That one is
240  * set to IP[2] so it is handled.  This is needed so we
241  * can do cross-cpu function calls, as required by SMP
242  */
243 
244 #define IMR_IP2_VAL	K_BCM1480_INT_MAP_I0
245 #define IMR_IP3_VAL	K_BCM1480_INT_MAP_I1
246 #define IMR_IP4_VAL	K_BCM1480_INT_MAP_I2
247 #define IMR_IP5_VAL	K_BCM1480_INT_MAP_I3
248 #define IMR_IP6_VAL	K_BCM1480_INT_MAP_I4
249 
250 void __init arch_init_irq(void)
251 {
252 	unsigned int i, cpu;
253 	u64 tmp;
254 	unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
255 		STATUSF_IP1 | STATUSF_IP0;
256 
257 	/* Default everything to IP2 */
258 	/* Start with _high registers which has no bit 0 interrupt source */
259 	for (i = 1; i < BCM1480_NR_IRQS_HALF; i++) {	/* was I0 */
260 		for (cpu = 0; cpu < 4; cpu++) {
261 			__raw_writeq(IMR_IP2_VAL,
262 				     IOADDR(A_BCM1480_IMR_REGISTER(cpu,
263 								   R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) + (i << 3)));
264 		}
265 	}
266 
267 	/* Now do _low registers */
268 	for (i = 0; i < BCM1480_NR_IRQS_HALF; i++) {
269 		for (cpu = 0; cpu < 4; cpu++) {
270 			__raw_writeq(IMR_IP2_VAL,
271 				     IOADDR(A_BCM1480_IMR_REGISTER(cpu,
272 								   R_BCM1480_IMR_INTERRUPT_MAP_BASE_L) + (i << 3)));
273 		}
274 	}
275 
276 	init_bcm1480_irqs();
277 
278 	/*
279 	 * Map the high 16 bits of mailbox_0 registers to IP[3], for
280 	 * inter-cpu messages
281 	 */
282 	/* Was I1 */
283 	for (cpu = 0; cpu < 4; cpu++) {
284 		__raw_writeq(IMR_IP3_VAL, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) +
285 						 (K_BCM1480_INT_MBOX_0_0 << 3)));
286         }
287 
288 
289 	/* Clear the mailboxes.  The firmware may leave them dirty */
290 	for (cpu = 0; cpu < 4; cpu++) {
291 		__raw_writeq(0xffffffffffffffffULL,
292 			     IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_MAILBOX_0_CLR_CPU)));
293 		__raw_writeq(0xffffffffffffffffULL,
294 			     IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_MAILBOX_1_CLR_CPU)));
295 	}
296 
297 
298 	/* Mask everything except the high 16 bit of mailbox_0 registers for all cpus */
299 	tmp = ~((u64) 0) ^ ( (((u64) 1) << K_BCM1480_INT_MBOX_0_0));
300 	for (cpu = 0; cpu < 4; cpu++) {
301 		__raw_writeq(tmp, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MASK_H)));
302 	}
303 	tmp = ~((u64) 0);
304 	for (cpu = 0; cpu < 4; cpu++) {
305 		__raw_writeq(tmp, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MASK_L)));
306 	}
307 
308 	/*
309 	 * Note that the timer interrupts are also mapped, but this is
310 	 * done in bcm1480_time_init().  Also, the profiling driver
311 	 * does its own management of IP7.
312 	 */
313 
314 	/* Enable necessary IPs, disable the rest */
315 	change_c0_status(ST0_IM, imask);
316 }
317 
318 extern void bcm1480_mailbox_interrupt(void);
319 
320 static inline void dispatch_ip2(void)
321 {
322 	unsigned long long mask_h, mask_l;
323 	unsigned int cpu = smp_processor_id();
324 	unsigned long base;
325 
326 	/*
327 	 * Default...we've hit an IP[2] interrupt, which means we've got to
328 	 * check the 1480 interrupt registers to figure out what to do.  Need
329 	 * to detect which CPU we're on, now that smp_affinity is supported.
330 	 */
331 	base = A_BCM1480_IMR_MAPPER(cpu);
332 	mask_h = __raw_readq(
333 		IOADDR(base + R_BCM1480_IMR_INTERRUPT_STATUS_BASE_H));
334 	mask_l = __raw_readq(
335 		IOADDR(base + R_BCM1480_IMR_INTERRUPT_STATUS_BASE_L));
336 
337 	if (mask_h) {
338 		if (mask_h ^ 1)
339 			do_IRQ(fls64(mask_h) - 1);
340 		else if (mask_l)
341 			do_IRQ(63 + fls64(mask_l));
342 	}
343 }
344 
345 asmlinkage void plat_irq_dispatch(void)
346 {
347 	unsigned int cpu = smp_processor_id();
348 	unsigned int pending;
349 
350 #ifdef CONFIG_SIBYTE_BCM1480_PROF
351 	/* Set compare to count to silence count/compare timer interrupts */
352 	write_c0_compare(read_c0_count());
353 #endif
354 
355 	pending = read_c0_cause() & read_c0_status();
356 
357 #ifdef CONFIG_SIBYTE_BCM1480_PROF
358 	if (pending & CAUSEF_IP7)	/* Cpu performance counter interrupt */
359 		sbprof_cpu_intr();
360 	else
361 #endif
362 
363 	if (pending & CAUSEF_IP4)
364 		do_IRQ(K_BCM1480_INT_TIMER_0 + cpu);
365 #ifdef CONFIG_SMP
366 	else if (pending & CAUSEF_IP3)
367 		bcm1480_mailbox_interrupt();
368 #endif
369 
370 	else if (pending & CAUSEF_IP2)
371 		dispatch_ip2();
372 }
373