1 /*
2 * Code to handle x86 style IRQs plus some generic interrupt stuff.
3 *
4 * Copyright (C) 1992 Linus Torvalds
5 * Copyright (C) 1994, 1995, 1996, 1997, 1998 Ralf Baechle
6 * Copyright (C) 1999 SuSE GmbH (Philipp Rumpf, prumpf@tux.org)
7 * Copyright (C) 1999-2000 Grant Grundler
8 * Copyright (c) 2005 Matthew Wilcox
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2, or (at your option)
13 * any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 */
24 #include <linux/bitops.h>
25 #include <linux/errno.h>
26 #include <linux/init.h>
27 #include <linux/interrupt.h>
28 #include <linux/kernel_stat.h>
29 #include <linux/seq_file.h>
30 #include <linux/spinlock.h>
31 #include <linux/types.h>
32 #include <asm/io.h>
33
34 #include <asm/smp.h>
35
36 #undef PARISC_IRQ_CR16_COUNTS
37
38 extern irqreturn_t timer_interrupt(int, void *);
39 extern irqreturn_t ipi_interrupt(int, void *);
40
41 #define EIEM_MASK(irq) (1UL<<(CPU_IRQ_MAX - irq))
42
43 /* Bits in EIEM correlate with cpu_irq_action[].
44 ** Numbered *Big Endian*! (ie bit 0 is MSB)
45 */
46 static volatile unsigned long cpu_eiem = 0;
47
48 /*
49 ** local ACK bitmap ... habitually set to 1, but reset to zero
50 ** between ->ack() and ->end() of the interrupt to prevent
51 ** re-interruption of a processing interrupt.
52 */
53 static DEFINE_PER_CPU(unsigned long, local_ack_eiem) = ~0UL;
54
cpu_mask_irq(struct irq_data * d)55 static void cpu_mask_irq(struct irq_data *d)
56 {
57 unsigned long eirr_bit = EIEM_MASK(d->irq);
58
59 cpu_eiem &= ~eirr_bit;
60 /* Do nothing on the other CPUs. If they get this interrupt,
61 * The & cpu_eiem in the do_cpu_irq_mask() ensures they won't
62 * handle it, and the set_eiem() at the bottom will ensure it
63 * then gets disabled */
64 }
65
__cpu_unmask_irq(unsigned int irq)66 static void __cpu_unmask_irq(unsigned int irq)
67 {
68 unsigned long eirr_bit = EIEM_MASK(irq);
69
70 cpu_eiem |= eirr_bit;
71
72 /* This is just a simple NOP IPI. But what it does is cause
73 * all the other CPUs to do a set_eiem(cpu_eiem) at the end
74 * of the interrupt handler */
75 smp_send_all_nop();
76 }
77
cpu_unmask_irq(struct irq_data * d)78 static void cpu_unmask_irq(struct irq_data *d)
79 {
80 __cpu_unmask_irq(d->irq);
81 }
82
cpu_ack_irq(struct irq_data * d)83 void cpu_ack_irq(struct irq_data *d)
84 {
85 unsigned long mask = EIEM_MASK(d->irq);
86 int cpu = smp_processor_id();
87
88 /* Clear in EIEM so we can no longer process */
89 per_cpu(local_ack_eiem, cpu) &= ~mask;
90
91 /* disable the interrupt */
92 set_eiem(cpu_eiem & per_cpu(local_ack_eiem, cpu));
93
94 /* and now ack it */
95 mtctl(mask, 23);
96 }
97
cpu_eoi_irq(struct irq_data * d)98 void cpu_eoi_irq(struct irq_data *d)
99 {
100 unsigned long mask = EIEM_MASK(d->irq);
101 int cpu = smp_processor_id();
102
103 /* set it in the eiems---it's no longer in process */
104 per_cpu(local_ack_eiem, cpu) |= mask;
105
106 /* enable the interrupt */
107 set_eiem(cpu_eiem & per_cpu(local_ack_eiem, cpu));
108 }
109
110 #ifdef CONFIG_SMP
cpu_check_affinity(struct irq_data * d,const struct cpumask * dest)111 int cpu_check_affinity(struct irq_data *d, const struct cpumask *dest)
112 {
113 int cpu_dest;
114
115 /* timer and ipi have to always be received on all CPUs */
116 if (irqd_is_per_cpu(d))
117 return -EINVAL;
118
119 /* whatever mask they set, we just allow one CPU */
120 cpu_dest = first_cpu(*dest);
121
122 return cpu_dest;
123 }
124
cpu_set_affinity_irq(struct irq_data * d,const struct cpumask * dest,bool force)125 static int cpu_set_affinity_irq(struct irq_data *d, const struct cpumask *dest,
126 bool force)
127 {
128 int cpu_dest;
129
130 cpu_dest = cpu_check_affinity(d, dest);
131 if (cpu_dest < 0)
132 return -1;
133
134 cpumask_copy(d->affinity, dest);
135
136 return 0;
137 }
138 #endif
139
140 static struct irq_chip cpu_interrupt_type = {
141 .name = "CPU",
142 .irq_mask = cpu_mask_irq,
143 .irq_unmask = cpu_unmask_irq,
144 .irq_ack = cpu_ack_irq,
145 .irq_eoi = cpu_eoi_irq,
146 #ifdef CONFIG_SMP
147 .irq_set_affinity = cpu_set_affinity_irq,
148 #endif
149 /* XXX: Needs to be written. We managed without it so far, but
150 * we really ought to write it.
151 */
152 .irq_retrigger = NULL,
153 };
154
show_interrupts(struct seq_file * p,void * v)155 int show_interrupts(struct seq_file *p, void *v)
156 {
157 int i = *(loff_t *) v, j;
158 unsigned long flags;
159
160 if (i == 0) {
161 seq_puts(p, " ");
162 for_each_online_cpu(j)
163 seq_printf(p, " CPU%d", j);
164
165 #ifdef PARISC_IRQ_CR16_COUNTS
166 seq_printf(p, " [min/avg/max] (CPU cycle counts)");
167 #endif
168 seq_putc(p, '\n');
169 }
170
171 if (i < NR_IRQS) {
172 struct irq_desc *desc = irq_to_desc(i);
173 struct irqaction *action;
174
175 raw_spin_lock_irqsave(&desc->lock, flags);
176 action = desc->action;
177 if (!action)
178 goto skip;
179 seq_printf(p, "%3d: ", i);
180 #ifdef CONFIG_SMP
181 for_each_online_cpu(j)
182 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
183 #else
184 seq_printf(p, "%10u ", kstat_irqs(i));
185 #endif
186
187 seq_printf(p, " %14s", irq_desc_get_chip(desc)->name);
188 #ifndef PARISC_IRQ_CR16_COUNTS
189 seq_printf(p, " %s", action->name);
190
191 while ((action = action->next))
192 seq_printf(p, ", %s", action->name);
193 #else
194 for ( ;action; action = action->next) {
195 unsigned int k, avg, min, max;
196
197 min = max = action->cr16_hist[0];
198
199 for (avg = k = 0; k < PARISC_CR16_HIST_SIZE; k++) {
200 int hist = action->cr16_hist[k];
201
202 if (hist) {
203 avg += hist;
204 } else
205 break;
206
207 if (hist > max) max = hist;
208 if (hist < min) min = hist;
209 }
210
211 avg /= k;
212 seq_printf(p, " %s[%d/%d/%d]", action->name,
213 min,avg,max);
214 }
215 #endif
216
217 seq_putc(p, '\n');
218 skip:
219 raw_spin_unlock_irqrestore(&desc->lock, flags);
220 }
221
222 return 0;
223 }
224
225
226
227 /*
228 ** The following form a "set": Virtual IRQ, Transaction Address, Trans Data.
229 ** Respectively, these map to IRQ region+EIRR, Processor HPA, EIRR bit.
230 **
231 ** To use txn_XXX() interfaces, get a Virtual IRQ first.
232 ** Then use that to get the Transaction address and data.
233 */
234
cpu_claim_irq(unsigned int irq,struct irq_chip * type,void * data)235 int cpu_claim_irq(unsigned int irq, struct irq_chip *type, void *data)
236 {
237 if (irq_has_action(irq))
238 return -EBUSY;
239 if (irq_get_chip(irq) != &cpu_interrupt_type)
240 return -EBUSY;
241
242 /* for iosapic interrupts */
243 if (type) {
244 irq_set_chip_and_handler(irq, type, handle_percpu_irq);
245 irq_set_chip_data(irq, data);
246 __cpu_unmask_irq(irq);
247 }
248 return 0;
249 }
250
txn_claim_irq(int irq)251 int txn_claim_irq(int irq)
252 {
253 return cpu_claim_irq(irq, NULL, NULL) ? -1 : irq;
254 }
255
256 /*
257 * The bits_wide parameter accommodates the limitations of the HW/SW which
258 * use these bits:
259 * Legacy PA I/O (GSC/NIO): 5 bits (architected EIM register)
260 * V-class (EPIC): 6 bits
261 * N/L/A-class (iosapic): 8 bits
262 * PCI 2.2 MSI: 16 bits
263 * Some PCI devices: 32 bits (Symbios SCSI/ATM/HyperFabric)
264 *
265 * On the service provider side:
266 * o PA 1.1 (and PA2.0 narrow mode) 5-bits (width of EIR register)
267 * o PA 2.0 wide mode 6-bits (per processor)
268 * o IA64 8-bits (0-256 total)
269 *
270 * So a Legacy PA I/O device on a PA 2.0 box can't use all the bits supported
271 * by the processor...and the N/L-class I/O subsystem supports more bits than
272 * PA2.0 has. The first case is the problem.
273 */
txn_alloc_irq(unsigned int bits_wide)274 int txn_alloc_irq(unsigned int bits_wide)
275 {
276 int irq;
277
278 /* never return irq 0 cause that's the interval timer */
279 for (irq = CPU_IRQ_BASE + 1; irq <= CPU_IRQ_MAX; irq++) {
280 if (cpu_claim_irq(irq, NULL, NULL) < 0)
281 continue;
282 if ((irq - CPU_IRQ_BASE) >= (1 << bits_wide))
283 continue;
284 return irq;
285 }
286
287 /* unlikely, but be prepared */
288 return -1;
289 }
290
291
txn_affinity_addr(unsigned int irq,int cpu)292 unsigned long txn_affinity_addr(unsigned int irq, int cpu)
293 {
294 #ifdef CONFIG_SMP
295 struct irq_data *d = irq_get_irq_data(irq);
296 cpumask_copy(d->affinity, cpumask_of(cpu));
297 #endif
298
299 return per_cpu(cpu_data, cpu).txn_addr;
300 }
301
302
txn_alloc_addr(unsigned int virt_irq)303 unsigned long txn_alloc_addr(unsigned int virt_irq)
304 {
305 static int next_cpu = -1;
306
307 next_cpu++; /* assign to "next" CPU we want this bugger on */
308
309 /* validate entry */
310 while ((next_cpu < nr_cpu_ids) &&
311 (!per_cpu(cpu_data, next_cpu).txn_addr ||
312 !cpu_online(next_cpu)))
313 next_cpu++;
314
315 if (next_cpu >= nr_cpu_ids)
316 next_cpu = 0; /* nothing else, assign monarch */
317
318 return txn_affinity_addr(virt_irq, next_cpu);
319 }
320
321
txn_alloc_data(unsigned int virt_irq)322 unsigned int txn_alloc_data(unsigned int virt_irq)
323 {
324 return virt_irq - CPU_IRQ_BASE;
325 }
326
eirr_to_irq(unsigned long eirr)327 static inline int eirr_to_irq(unsigned long eirr)
328 {
329 int bit = fls_long(eirr);
330 return (BITS_PER_LONG - bit) + TIMER_IRQ;
331 }
332
333 /* ONLY called from entry.S:intr_extint() */
do_cpu_irq_mask(struct pt_regs * regs)334 void do_cpu_irq_mask(struct pt_regs *regs)
335 {
336 struct pt_regs *old_regs;
337 unsigned long eirr_val;
338 int irq, cpu = smp_processor_id();
339 #ifdef CONFIG_SMP
340 struct irq_desc *desc;
341 cpumask_t dest;
342 #endif
343
344 old_regs = set_irq_regs(regs);
345 local_irq_disable();
346 irq_enter();
347
348 eirr_val = mfctl(23) & cpu_eiem & per_cpu(local_ack_eiem, cpu);
349 if (!eirr_val)
350 goto set_out;
351 irq = eirr_to_irq(eirr_val);
352
353 #ifdef CONFIG_SMP
354 desc = irq_to_desc(irq);
355 cpumask_copy(&dest, desc->irq_data.affinity);
356 if (irqd_is_per_cpu(&desc->irq_data) &&
357 !cpu_isset(smp_processor_id(), dest)) {
358 int cpu = first_cpu(dest);
359
360 printk(KERN_DEBUG "redirecting irq %d from CPU %d to %d\n",
361 irq, smp_processor_id(), cpu);
362 gsc_writel(irq + CPU_IRQ_BASE,
363 per_cpu(cpu_data, cpu).hpa);
364 goto set_out;
365 }
366 #endif
367 generic_handle_irq(irq);
368
369 out:
370 irq_exit();
371 set_irq_regs(old_regs);
372 return;
373
374 set_out:
375 set_eiem(cpu_eiem & per_cpu(local_ack_eiem, cpu));
376 goto out;
377 }
378
379 static struct irqaction timer_action = {
380 .handler = timer_interrupt,
381 .name = "timer",
382 .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_PERCPU | IRQF_IRQPOLL,
383 };
384
385 #ifdef CONFIG_SMP
386 static struct irqaction ipi_action = {
387 .handler = ipi_interrupt,
388 .name = "IPI",
389 .flags = IRQF_DISABLED | IRQF_PERCPU,
390 };
391 #endif
392
claim_cpu_irqs(void)393 static void claim_cpu_irqs(void)
394 {
395 int i;
396 for (i = CPU_IRQ_BASE; i <= CPU_IRQ_MAX; i++) {
397 irq_set_chip_and_handler(i, &cpu_interrupt_type,
398 handle_percpu_irq);
399 }
400
401 irq_set_handler(TIMER_IRQ, handle_percpu_irq);
402 setup_irq(TIMER_IRQ, &timer_action);
403 #ifdef CONFIG_SMP
404 irq_set_handler(IPI_IRQ, handle_percpu_irq);
405 setup_irq(IPI_IRQ, &ipi_action);
406 #endif
407 }
408
init_IRQ(void)409 void __init init_IRQ(void)
410 {
411 local_irq_disable(); /* PARANOID - should already be disabled */
412 mtctl(~0UL, 23); /* EIRR : clear all pending external intr */
413 claim_cpu_irqs();
414 #ifdef CONFIG_SMP
415 if (!cpu_eiem)
416 cpu_eiem = EIEM_MASK(IPI_IRQ) | EIEM_MASK(TIMER_IRQ);
417 #else
418 cpu_eiem = EIEM_MASK(TIMER_IRQ);
419 #endif
420 set_eiem(cpu_eiem); /* EIEM : enable all external intr */
421
422 }
423
424