xref: /openbmc/linux/arch/powerpc/sysdev/mpic.c (revision a9c59264)
1 /*
2  *  arch/powerpc/kernel/mpic.c
3  *
4  *  Driver for interrupt controllers following the OpenPIC standard, the
5  *  common implementation beeing IBM's MPIC. This driver also can deal
6  *  with various broken implementations of this HW.
7  *
8  *  Copyright (C) 2004 Benjamin Herrenschmidt, IBM Corp.
9  *
10  *  This file is subject to the terms and conditions of the GNU General Public
11  *  License.  See the file COPYING in the main directory of this archive
12  *  for more details.
13  */
14 
15 #undef DEBUG
16 
17 #include <linux/config.h>
18 #include <linux/types.h>
19 #include <linux/kernel.h>
20 #include <linux/init.h>
21 #include <linux/irq.h>
22 #include <linux/smp.h>
23 #include <linux/interrupt.h>
24 #include <linux/bootmem.h>
25 #include <linux/spinlock.h>
26 #include <linux/pci.h>
27 
28 #include <asm/ptrace.h>
29 #include <asm/signal.h>
30 #include <asm/io.h>
31 #include <asm/pgtable.h>
32 #include <asm/irq.h>
33 #include <asm/machdep.h>
34 #include <asm/mpic.h>
35 #include <asm/smp.h>
36 
37 #ifdef DEBUG
38 #define DBG(fmt...) printk(fmt)
39 #else
40 #define DBG(fmt...)
41 #endif
42 
43 static struct mpic *mpics;
44 static struct mpic *mpic_primary;
45 static DEFINE_SPINLOCK(mpic_lock);
46 
47 #ifdef CONFIG_PPC32	/* XXX for now */
48 #define distribute_irqs	CONFIG_IRQ_ALL_CPUS
49 #endif
50 
51 /*
52  * Register accessor functions
53  */
54 
55 
56 static inline u32 _mpic_read(unsigned int be, volatile u32 __iomem *base,
57 			    unsigned int reg)
58 {
59 	if (be)
60 		return in_be32(base + (reg >> 2));
61 	else
62 		return in_le32(base + (reg >> 2));
63 }
64 
65 static inline void _mpic_write(unsigned int be, volatile u32 __iomem *base,
66 			      unsigned int reg, u32 value)
67 {
68 	if (be)
69 		out_be32(base + (reg >> 2), value);
70 	else
71 		out_le32(base + (reg >> 2), value);
72 }
73 
74 static inline u32 _mpic_ipi_read(struct mpic *mpic, unsigned int ipi)
75 {
76 	unsigned int be = (mpic->flags & MPIC_BIG_ENDIAN) != 0;
77 	unsigned int offset = MPIC_GREG_IPI_VECTOR_PRI_0 + (ipi * 0x10);
78 
79 	if (mpic->flags & MPIC_BROKEN_IPI)
80 		be = !be;
81 	return _mpic_read(be, mpic->gregs, offset);
82 }
83 
84 static inline void _mpic_ipi_write(struct mpic *mpic, unsigned int ipi, u32 value)
85 {
86 	unsigned int offset = MPIC_GREG_IPI_VECTOR_PRI_0 + (ipi * 0x10);
87 
88 	_mpic_write(mpic->flags & MPIC_BIG_ENDIAN, mpic->gregs, offset, value);
89 }
90 
91 static inline u32 _mpic_cpu_read(struct mpic *mpic, unsigned int reg)
92 {
93 	unsigned int cpu = 0;
94 
95 	if (mpic->flags & MPIC_PRIMARY)
96 		cpu = hard_smp_processor_id();
97 
98 	return _mpic_read(mpic->flags & MPIC_BIG_ENDIAN, mpic->cpuregs[cpu], reg);
99 }
100 
101 static inline void _mpic_cpu_write(struct mpic *mpic, unsigned int reg, u32 value)
102 {
103 	unsigned int cpu = 0;
104 
105 	if (mpic->flags & MPIC_PRIMARY)
106 		cpu = hard_smp_processor_id();
107 
108 	_mpic_write(mpic->flags & MPIC_BIG_ENDIAN, mpic->cpuregs[cpu], reg, value);
109 }
110 
111 static inline u32 _mpic_irq_read(struct mpic *mpic, unsigned int src_no, unsigned int reg)
112 {
113 	unsigned int	isu = src_no >> mpic->isu_shift;
114 	unsigned int	idx = src_no & mpic->isu_mask;
115 
116 	return _mpic_read(mpic->flags & MPIC_BIG_ENDIAN, mpic->isus[isu],
117 			  reg + (idx * MPIC_IRQ_STRIDE));
118 }
119 
120 static inline void _mpic_irq_write(struct mpic *mpic, unsigned int src_no,
121 				   unsigned int reg, u32 value)
122 {
123 	unsigned int	isu = src_no >> mpic->isu_shift;
124 	unsigned int	idx = src_no & mpic->isu_mask;
125 
126 	_mpic_write(mpic->flags & MPIC_BIG_ENDIAN, mpic->isus[isu],
127 		    reg + (idx * MPIC_IRQ_STRIDE), value);
128 }
129 
130 #define mpic_read(b,r)		_mpic_read(mpic->flags & MPIC_BIG_ENDIAN,(b),(r))
131 #define mpic_write(b,r,v)	_mpic_write(mpic->flags & MPIC_BIG_ENDIAN,(b),(r),(v))
132 #define mpic_ipi_read(i)	_mpic_ipi_read(mpic,(i))
133 #define mpic_ipi_write(i,v)	_mpic_ipi_write(mpic,(i),(v))
134 #define mpic_cpu_read(i)	_mpic_cpu_read(mpic,(i))
135 #define mpic_cpu_write(i,v)	_mpic_cpu_write(mpic,(i),(v))
136 #define mpic_irq_read(s,r)	_mpic_irq_read(mpic,(s),(r))
137 #define mpic_irq_write(s,r,v)	_mpic_irq_write(mpic,(s),(r),(v))
138 
139 
140 /*
141  * Low level utility functions
142  */
143 
144 
145 
146 /* Check if we have one of those nice broken MPICs with a flipped endian on
147  * reads from IPI registers
148  */
149 static void __init mpic_test_broken_ipi(struct mpic *mpic)
150 {
151 	u32 r;
152 
153 	mpic_write(mpic->gregs, MPIC_GREG_IPI_VECTOR_PRI_0, MPIC_VECPRI_MASK);
154 	r = mpic_read(mpic->gregs, MPIC_GREG_IPI_VECTOR_PRI_0);
155 
156 	if (r == le32_to_cpu(MPIC_VECPRI_MASK)) {
157 		printk(KERN_INFO "mpic: Detected reversed IPI registers\n");
158 		mpic->flags |= MPIC_BROKEN_IPI;
159 	}
160 }
161 
162 #ifdef CONFIG_MPIC_BROKEN_U3
163 
164 /* Test if an interrupt is sourced from HyperTransport (used on broken U3s)
165  * to force the edge setting on the MPIC and do the ack workaround.
166  */
167 static inline int mpic_is_ht_interrupt(struct mpic *mpic, unsigned int source_no)
168 {
169 	if (source_no >= 128 || !mpic->fixups)
170 		return 0;
171 	return mpic->fixups[source_no].base != NULL;
172 }
173 
174 static inline void mpic_apic_end_irq(struct mpic *mpic, unsigned int source_no)
175 {
176 	struct mpic_irq_fixup *fixup = &mpic->fixups[source_no];
177 	u32 tmp;
178 
179 	spin_lock(&mpic->fixup_lock);
180 	writeb(0x11 + 2 * fixup->irq, fixup->base);
181 	tmp = readl(fixup->base + 2);
182 	writel(tmp | 0x80000000ul, fixup->base + 2);
183 	/* config writes shouldn't be posted but let's be safe ... */
184 	(void)readl(fixup->base + 2);
185 	spin_unlock(&mpic->fixup_lock);
186 }
187 
188 
189 static void __init mpic_amd8111_read_irq(struct mpic *mpic, u8 __iomem *devbase)
190 {
191 	int i, irq;
192 	u32 tmp;
193 
194 	printk(KERN_INFO "mpic:    - Workarounds on AMD 8111 @ %p\n", devbase);
195 
196 	for (i=0; i < 24; i++) {
197 		writeb(0x10 + 2*i, devbase + 0xf2);
198 		tmp = readl(devbase + 0xf4);
199 		if ((tmp & 0x1) || !(tmp & 0x20))
200 			continue;
201 		irq = (tmp >> 16) & 0xff;
202 		mpic->fixups[irq].irq = i;
203 		mpic->fixups[irq].base = devbase + 0xf2;
204 	}
205 }
206 
207 static void __init mpic_amd8131_read_irq(struct mpic *mpic, u8 __iomem *devbase)
208 {
209 	int i, irq;
210 	u32 tmp;
211 
212 	printk(KERN_INFO "mpic:    - Workarounds on AMD 8131 @ %p\n", devbase);
213 
214 	for (i=0; i < 4; i++) {
215 		writeb(0x10 + 2*i, devbase + 0xba);
216 		tmp = readl(devbase + 0xbc);
217 		if ((tmp & 0x1) || !(tmp & 0x20))
218 			continue;
219 		irq = (tmp >> 16) & 0xff;
220 		mpic->fixups[irq].irq = i;
221 		mpic->fixups[irq].base = devbase + 0xba;
222 	}
223 }
224 
225 static void __init mpic_scan_ioapics(struct mpic *mpic)
226 {
227 	unsigned int devfn;
228 	u8 __iomem *cfgspace;
229 
230 	printk(KERN_INFO "mpic: Setting up IO-APICs workarounds for U3\n");
231 
232 	/* Allocate fixups array */
233 	mpic->fixups = alloc_bootmem(128 * sizeof(struct mpic_irq_fixup));
234 	BUG_ON(mpic->fixups == NULL);
235 	memset(mpic->fixups, 0, 128 * sizeof(struct mpic_irq_fixup));
236 
237 	/* Init spinlock */
238 	spin_lock_init(&mpic->fixup_lock);
239 
240 	/* Map u3 config space. We assume all IO-APICs are on the primary bus
241 	 * and slot will never be above "0xf" so we only need to map 32k
242 	 */
243 	cfgspace = (unsigned char __iomem *)ioremap(0xf2000000, 0x8000);
244 	BUG_ON(cfgspace == NULL);
245 
246 	/* Now we scan all slots. We do a very quick scan, we read the header type,
247 	 * vendor ID and device ID only, that's plenty enough
248 	 */
249 	for (devfn = 0; devfn < PCI_DEVFN(0x10,0); devfn ++) {
250 		u8 __iomem *devbase = cfgspace + (devfn << 8);
251 		u8 hdr_type = readb(devbase + PCI_HEADER_TYPE);
252 		u32 l = readl(devbase + PCI_VENDOR_ID);
253 		u16 vendor_id, device_id;
254 		int multifunc = 0;
255 
256 		DBG("devfn %x, l: %x\n", devfn, l);
257 
258 		/* If no device, skip */
259 		if (l == 0xffffffff || l == 0x00000000 ||
260 		    l == 0x0000ffff || l == 0xffff0000)
261 			goto next;
262 
263 		/* Check if it's a multifunction device (only really used
264 		 * to function 0 though
265 		 */
266 		multifunc = !!(hdr_type & 0x80);
267 		vendor_id = l & 0xffff;
268 		device_id = (l >> 16) & 0xffff;
269 
270 		/* If a known device, go to fixup setup code */
271 		if (vendor_id == PCI_VENDOR_ID_AMD && device_id == 0x7460)
272 			mpic_amd8111_read_irq(mpic, devbase);
273 		if (vendor_id == PCI_VENDOR_ID_AMD && device_id == 0x7450)
274 			mpic_amd8131_read_irq(mpic, devbase);
275 	next:
276 		/* next device, if function 0 */
277 		if ((PCI_FUNC(devfn) == 0) && !multifunc)
278 			devfn += 7;
279 	}
280 }
281 
282 #endif /* CONFIG_MPIC_BROKEN_U3 */
283 
284 
285 /* Find an mpic associated with a given linux interrupt */
286 static struct mpic *mpic_find(unsigned int irq, unsigned int *is_ipi)
287 {
288 	struct mpic *mpic = mpics;
289 
290 	while(mpic) {
291 		/* search IPIs first since they may override the main interrupts */
292 		if (irq >= mpic->ipi_offset && irq < (mpic->ipi_offset + 4)) {
293 			if (is_ipi)
294 				*is_ipi = 1;
295 			return mpic;
296 		}
297 		if (irq >= mpic->irq_offset &&
298 		    irq < (mpic->irq_offset + mpic->irq_count)) {
299 			if (is_ipi)
300 				*is_ipi = 0;
301 			return mpic;
302 		}
303 		mpic = mpic -> next;
304 	}
305 	return NULL;
306 }
307 
308 /* Convert a cpu mask from logical to physical cpu numbers. */
309 static inline u32 mpic_physmask(u32 cpumask)
310 {
311 	int i;
312 	u32 mask = 0;
313 
314 	for (i = 0; i < NR_CPUS; ++i, cpumask >>= 1)
315 		mask |= (cpumask & 1) << get_hard_smp_processor_id(i);
316 	return mask;
317 }
318 
319 #ifdef CONFIG_SMP
320 /* Get the mpic structure from the IPI number */
321 static inline struct mpic * mpic_from_ipi(unsigned int ipi)
322 {
323 	return container_of(irq_desc[ipi].handler, struct mpic, hc_ipi);
324 }
325 #endif
326 
327 /* Get the mpic structure from the irq number */
328 static inline struct mpic * mpic_from_irq(unsigned int irq)
329 {
330 	return container_of(irq_desc[irq].handler, struct mpic, hc_irq);
331 }
332 
333 /* Send an EOI */
334 static inline void mpic_eoi(struct mpic *mpic)
335 {
336 	mpic_cpu_write(MPIC_CPU_EOI, 0);
337 	(void)mpic_cpu_read(MPIC_CPU_WHOAMI);
338 }
339 
340 #ifdef CONFIG_SMP
341 static irqreturn_t mpic_ipi_action(int irq, void *dev_id, struct pt_regs *regs)
342 {
343 	struct mpic *mpic = dev_id;
344 
345 	smp_message_recv(irq - mpic->ipi_offset, regs);
346 	return IRQ_HANDLED;
347 }
348 #endif /* CONFIG_SMP */
349 
350 /*
351  * Linux descriptor level callbacks
352  */
353 
354 
355 static void mpic_enable_irq(unsigned int irq)
356 {
357 	unsigned int loops = 100000;
358 	struct mpic *mpic = mpic_from_irq(irq);
359 	unsigned int src = irq - mpic->irq_offset;
360 
361 	DBG("%s: enable_irq: %d (src %d)\n", mpic->name, irq, src);
362 
363 	mpic_irq_write(src, MPIC_IRQ_VECTOR_PRI,
364 		       mpic_irq_read(src, MPIC_IRQ_VECTOR_PRI) & ~MPIC_VECPRI_MASK);
365 
366 	/* make sure mask gets to controller before we return to user */
367 	do {
368 		if (!loops--) {
369 			printk(KERN_ERR "mpic_enable_irq timeout\n");
370 			break;
371 		}
372 	} while(mpic_irq_read(src, MPIC_IRQ_VECTOR_PRI) & MPIC_VECPRI_MASK);
373 }
374 
375 static void mpic_disable_irq(unsigned int irq)
376 {
377 	unsigned int loops = 100000;
378 	struct mpic *mpic = mpic_from_irq(irq);
379 	unsigned int src = irq - mpic->irq_offset;
380 
381 	DBG("%s: disable_irq: %d (src %d)\n", mpic->name, irq, src);
382 
383 	mpic_irq_write(src, MPIC_IRQ_VECTOR_PRI,
384 		       mpic_irq_read(src, MPIC_IRQ_VECTOR_PRI) | MPIC_VECPRI_MASK);
385 
386 	/* make sure mask gets to controller before we return to user */
387 	do {
388 		if (!loops--) {
389 			printk(KERN_ERR "mpic_enable_irq timeout\n");
390 			break;
391 		}
392 	} while(!(mpic_irq_read(src, MPIC_IRQ_VECTOR_PRI) & MPIC_VECPRI_MASK));
393 }
394 
395 static void mpic_end_irq(unsigned int irq)
396 {
397 	struct mpic *mpic = mpic_from_irq(irq);
398 
399 	DBG("%s: end_irq: %d\n", mpic->name, irq);
400 
401 	/* We always EOI on end_irq() even for edge interrupts since that
402 	 * should only lower the priority, the MPIC should have properly
403 	 * latched another edge interrupt coming in anyway
404 	 */
405 
406 #ifdef CONFIG_MPIC_BROKEN_U3
407 	if (mpic->flags & MPIC_BROKEN_U3) {
408 		unsigned int src = irq - mpic->irq_offset;
409 		if (mpic_is_ht_interrupt(mpic, src))
410 			mpic_apic_end_irq(mpic, src);
411 	}
412 #endif /* CONFIG_MPIC_BROKEN_U3 */
413 
414 	mpic_eoi(mpic);
415 }
416 
417 #ifdef CONFIG_SMP
418 
419 static void mpic_enable_ipi(unsigned int irq)
420 {
421 	struct mpic *mpic = mpic_from_ipi(irq);
422 	unsigned int src = irq - mpic->ipi_offset;
423 
424 	DBG("%s: enable_ipi: %d (ipi %d)\n", mpic->name, irq, src);
425 	mpic_ipi_write(src, mpic_ipi_read(src) & ~MPIC_VECPRI_MASK);
426 }
427 
428 static void mpic_disable_ipi(unsigned int irq)
429 {
430 	/* NEVER disable an IPI... that's just plain wrong! */
431 }
432 
433 static void mpic_end_ipi(unsigned int irq)
434 {
435 	struct mpic *mpic = mpic_from_ipi(irq);
436 
437 	/*
438 	 * IPIs are marked IRQ_PER_CPU. This has the side effect of
439 	 * preventing the IRQ_PENDING/IRQ_INPROGRESS logic from
440 	 * applying to them. We EOI them late to avoid re-entering.
441 	 * We mark IPI's with SA_INTERRUPT as they must run with
442 	 * irqs disabled.
443 	 */
444 	mpic_eoi(mpic);
445 }
446 
447 #endif /* CONFIG_SMP */
448 
449 static void mpic_set_affinity(unsigned int irq, cpumask_t cpumask)
450 {
451 	struct mpic *mpic = mpic_from_irq(irq);
452 
453 	cpumask_t tmp;
454 
455 	cpus_and(tmp, cpumask, cpu_online_map);
456 
457 	mpic_irq_write(irq - mpic->irq_offset, MPIC_IRQ_DESTINATION,
458 		       mpic_physmask(cpus_addr(tmp)[0]));
459 }
460 
461 
462 /*
463  * Exported functions
464  */
465 
466 
467 struct mpic * __init mpic_alloc(unsigned long phys_addr,
468 				unsigned int flags,
469 				unsigned int isu_size,
470 				unsigned int irq_offset,
471 				unsigned int irq_count,
472 				unsigned int ipi_offset,
473 				unsigned char *senses,
474 				unsigned int senses_count,
475 				const char *name)
476 {
477 	struct mpic	*mpic;
478 	u32		reg;
479 	const char	*vers;
480 	int		i;
481 
482 	mpic = alloc_bootmem(sizeof(struct mpic));
483 	if (mpic == NULL)
484 		return NULL;
485 
486 
487 	memset(mpic, 0, sizeof(struct mpic));
488 	mpic->name = name;
489 
490 	mpic->hc_irq.typename = name;
491 	mpic->hc_irq.enable = mpic_enable_irq;
492 	mpic->hc_irq.disable = mpic_disable_irq;
493 	mpic->hc_irq.end = mpic_end_irq;
494 	if (flags & MPIC_PRIMARY)
495 		mpic->hc_irq.set_affinity = mpic_set_affinity;
496 #ifdef CONFIG_SMP
497 	mpic->hc_ipi.typename = name;
498 	mpic->hc_ipi.enable = mpic_enable_ipi;
499 	mpic->hc_ipi.disable = mpic_disable_ipi;
500 	mpic->hc_ipi.end = mpic_end_ipi;
501 #endif /* CONFIG_SMP */
502 
503 	mpic->flags = flags;
504 	mpic->isu_size = isu_size;
505 	mpic->irq_offset = irq_offset;
506 	mpic->irq_count = irq_count;
507 	mpic->ipi_offset = ipi_offset;
508 	mpic->num_sources = 0; /* so far */
509 	mpic->senses = senses;
510 	mpic->senses_count = senses_count;
511 
512 	/* Map the global registers */
513 	mpic->gregs = ioremap(phys_addr + MPIC_GREG_BASE, 0x1000);
514 	mpic->tmregs = mpic->gregs + (MPIC_TIMER_BASE >> 2);
515 	BUG_ON(mpic->gregs == NULL);
516 
517 	/* Reset */
518 	if (flags & MPIC_WANTS_RESET) {
519 		mpic_write(mpic->gregs, MPIC_GREG_GLOBAL_CONF_0,
520 			   mpic_read(mpic->gregs, MPIC_GREG_GLOBAL_CONF_0)
521 			   | MPIC_GREG_GCONF_RESET);
522 		while( mpic_read(mpic->gregs, MPIC_GREG_GLOBAL_CONF_0)
523 		       & MPIC_GREG_GCONF_RESET)
524 			mb();
525 	}
526 
527 	/* Read feature register, calculate num CPUs and, for non-ISU
528 	 * MPICs, num sources as well. On ISU MPICs, sources are counted
529 	 * as ISUs are added
530 	 */
531 	reg = mpic_read(mpic->gregs, MPIC_GREG_FEATURE_0);
532 	mpic->num_cpus = ((reg & MPIC_GREG_FEATURE_LAST_CPU_MASK)
533 			  >> MPIC_GREG_FEATURE_LAST_CPU_SHIFT) + 1;
534 	if (isu_size == 0)
535 		mpic->num_sources = ((reg & MPIC_GREG_FEATURE_LAST_SRC_MASK)
536 				     >> MPIC_GREG_FEATURE_LAST_SRC_SHIFT) + 1;
537 
538 	/* Map the per-CPU registers */
539 	for (i = 0; i < mpic->num_cpus; i++) {
540 		mpic->cpuregs[i] = ioremap(phys_addr + MPIC_CPU_BASE +
541 					   i * MPIC_CPU_STRIDE, 0x1000);
542 		BUG_ON(mpic->cpuregs[i] == NULL);
543 	}
544 
545 	/* Initialize main ISU if none provided */
546 	if (mpic->isu_size == 0) {
547 		mpic->isu_size = mpic->num_sources;
548 		mpic->isus[0] = ioremap(phys_addr + MPIC_IRQ_BASE,
549 					MPIC_IRQ_STRIDE * mpic->isu_size);
550 		BUG_ON(mpic->isus[0] == NULL);
551 	}
552 	mpic->isu_shift = 1 + __ilog2(mpic->isu_size - 1);
553 	mpic->isu_mask = (1 << mpic->isu_shift) - 1;
554 
555 	/* Display version */
556 	switch (reg & MPIC_GREG_FEATURE_VERSION_MASK) {
557 	case 1:
558 		vers = "1.0";
559 		break;
560 	case 2:
561 		vers = "1.2";
562 		break;
563 	case 3:
564 		vers = "1.3";
565 		break;
566 	default:
567 		vers = "<unknown>";
568 		break;
569 	}
570 	printk(KERN_INFO "mpic: Setting up MPIC \"%s\" version %s at %lx, max %d CPUs\n",
571 	       name, vers, phys_addr, mpic->num_cpus);
572 	printk(KERN_INFO "mpic: ISU size: %d, shift: %d, mask: %x\n", mpic->isu_size,
573 	       mpic->isu_shift, mpic->isu_mask);
574 
575 	mpic->next = mpics;
576 	mpics = mpic;
577 
578 	if (flags & MPIC_PRIMARY)
579 		mpic_primary = mpic;
580 
581 	return mpic;
582 }
583 
584 void __init mpic_assign_isu(struct mpic *mpic, unsigned int isu_num,
585 			    unsigned long phys_addr)
586 {
587 	unsigned int isu_first = isu_num * mpic->isu_size;
588 
589 	BUG_ON(isu_num >= MPIC_MAX_ISU);
590 
591 	mpic->isus[isu_num] = ioremap(phys_addr, MPIC_IRQ_STRIDE * mpic->isu_size);
592 	if ((isu_first + mpic->isu_size) > mpic->num_sources)
593 		mpic->num_sources = isu_first + mpic->isu_size;
594 }
595 
596 void __init mpic_setup_cascade(unsigned int irq, mpic_cascade_t handler,
597 			       void *data)
598 {
599 	struct mpic *mpic = mpic_find(irq, NULL);
600 	unsigned long flags;
601 
602 	/* Synchronization here is a bit dodgy, so don't try to replace cascade
603 	 * interrupts on the fly too often ... but normally it's set up at boot.
604 	 */
605 	spin_lock_irqsave(&mpic_lock, flags);
606 	if (mpic->cascade)
607 		mpic_disable_irq(mpic->cascade_vec + mpic->irq_offset);
608 	mpic->cascade = NULL;
609 	wmb();
610 	mpic->cascade_vec = irq - mpic->irq_offset;
611 	mpic->cascade_data = data;
612 	wmb();
613 	mpic->cascade = handler;
614 	mpic_enable_irq(irq);
615 	spin_unlock_irqrestore(&mpic_lock, flags);
616 }
617 
618 void __init mpic_init(struct mpic *mpic)
619 {
620 	int i;
621 
622 	BUG_ON(mpic->num_sources == 0);
623 
624 	printk(KERN_INFO "mpic: Initializing for %d sources\n", mpic->num_sources);
625 
626 	/* Set current processor priority to max */
627 	mpic_cpu_write(MPIC_CPU_CURRENT_TASK_PRI, 0xf);
628 
629 	/* Initialize timers: just disable them all */
630 	for (i = 0; i < 4; i++) {
631 		mpic_write(mpic->tmregs,
632 			   i * MPIC_TIMER_STRIDE + MPIC_TIMER_DESTINATION, 0);
633 		mpic_write(mpic->tmregs,
634 			   i * MPIC_TIMER_STRIDE + MPIC_TIMER_VECTOR_PRI,
635 			   MPIC_VECPRI_MASK |
636 			   (MPIC_VEC_TIMER_0 + i));
637 	}
638 
639 	/* Initialize IPIs to our reserved vectors and mark them disabled for now */
640 	mpic_test_broken_ipi(mpic);
641 	for (i = 0; i < 4; i++) {
642 		mpic_ipi_write(i,
643 			       MPIC_VECPRI_MASK |
644 			       (10 << MPIC_VECPRI_PRIORITY_SHIFT) |
645 			       (MPIC_VEC_IPI_0 + i));
646 #ifdef CONFIG_SMP
647 		if (!(mpic->flags & MPIC_PRIMARY))
648 			continue;
649 		irq_desc[mpic->ipi_offset+i].status |= IRQ_PER_CPU;
650 		irq_desc[mpic->ipi_offset+i].handler = &mpic->hc_ipi;
651 
652 #endif /* CONFIG_SMP */
653 	}
654 
655 	/* Initialize interrupt sources */
656 	if (mpic->irq_count == 0)
657 		mpic->irq_count = mpic->num_sources;
658 
659 #ifdef CONFIG_MPIC_BROKEN_U3
660 	/* Do the ioapic fixups on U3 broken mpic */
661 	DBG("MPIC flags: %x\n", mpic->flags);
662 	if ((mpic->flags & MPIC_BROKEN_U3) && (mpic->flags & MPIC_PRIMARY))
663 		mpic_scan_ioapics(mpic);
664 #endif /* CONFIG_MPIC_BROKEN_U3 */
665 
666 	for (i = 0; i < mpic->num_sources; i++) {
667 		/* start with vector = source number, and masked */
668 		u32 vecpri = MPIC_VECPRI_MASK | i | (8 << MPIC_VECPRI_PRIORITY_SHIFT);
669 		int level = 0;
670 
671 		/* if it's an IPI, we skip it */
672 		if ((mpic->irq_offset + i) >= (mpic->ipi_offset + i) &&
673 		    (mpic->irq_offset + i) <  (mpic->ipi_offset + i + 4))
674 			continue;
675 
676 		/* do senses munging */
677 		if (mpic->senses && i < mpic->senses_count) {
678 			if (mpic->senses[i] & IRQ_SENSE_LEVEL)
679 				vecpri |= MPIC_VECPRI_SENSE_LEVEL;
680 			if (mpic->senses[i] & IRQ_POLARITY_POSITIVE)
681 				vecpri |= MPIC_VECPRI_POLARITY_POSITIVE;
682 		} else
683 			vecpri |= MPIC_VECPRI_SENSE_LEVEL;
684 
685 		/* remember if it was a level interrupts */
686 		level = (vecpri & MPIC_VECPRI_SENSE_LEVEL);
687 
688 		/* deal with broken U3 */
689 		if (mpic->flags & MPIC_BROKEN_U3) {
690 #ifdef CONFIG_MPIC_BROKEN_U3
691 			if (mpic_is_ht_interrupt(mpic, i)) {
692 				vecpri &= ~(MPIC_VECPRI_SENSE_MASK |
693 					    MPIC_VECPRI_POLARITY_MASK);
694 				vecpri |= MPIC_VECPRI_POLARITY_POSITIVE;
695 			}
696 #else
697 			printk(KERN_ERR "mpic: BROKEN_U3 set, but CONFIG doesn't match\n");
698 #endif
699 		}
700 
701 		DBG("setup source %d, vecpri: %08x, level: %d\n", i, vecpri,
702 		    (level != 0));
703 
704 		/* init hw */
705 		mpic_irq_write(i, MPIC_IRQ_VECTOR_PRI, vecpri);
706 		mpic_irq_write(i, MPIC_IRQ_DESTINATION,
707 			       1 << hard_smp_processor_id());
708 
709 		/* init linux descriptors */
710 		if (i < mpic->irq_count) {
711 			irq_desc[mpic->irq_offset+i].status = level ? IRQ_LEVEL : 0;
712 			irq_desc[mpic->irq_offset+i].handler = &mpic->hc_irq;
713 		}
714 	}
715 
716 	/* Init spurrious vector */
717 	mpic_write(mpic->gregs, MPIC_GREG_SPURIOUS, MPIC_VEC_SPURRIOUS);
718 
719 	/* Disable 8259 passthrough */
720 	mpic_write(mpic->gregs, MPIC_GREG_GLOBAL_CONF_0,
721 		   mpic_read(mpic->gregs, MPIC_GREG_GLOBAL_CONF_0)
722 		   | MPIC_GREG_GCONF_8259_PTHROU_DIS);
723 
724 	/* Set current processor priority to 0 */
725 	mpic_cpu_write(MPIC_CPU_CURRENT_TASK_PRI, 0);
726 }
727 
728 
729 
730 void mpic_irq_set_priority(unsigned int irq, unsigned int pri)
731 {
732 	int is_ipi;
733 	struct mpic *mpic = mpic_find(irq, &is_ipi);
734 	unsigned long flags;
735 	u32 reg;
736 
737 	spin_lock_irqsave(&mpic_lock, flags);
738 	if (is_ipi) {
739 		reg = mpic_ipi_read(irq - mpic->ipi_offset) & MPIC_VECPRI_PRIORITY_MASK;
740 		mpic_ipi_write(irq - mpic->ipi_offset,
741 			       reg | (pri << MPIC_VECPRI_PRIORITY_SHIFT));
742 	} else {
743 		reg = mpic_irq_read(irq - mpic->irq_offset, MPIC_IRQ_VECTOR_PRI)
744 			& MPIC_VECPRI_PRIORITY_MASK;
745 		mpic_irq_write(irq - mpic->irq_offset, MPIC_IRQ_VECTOR_PRI,
746 			       reg | (pri << MPIC_VECPRI_PRIORITY_SHIFT));
747 	}
748 	spin_unlock_irqrestore(&mpic_lock, flags);
749 }
750 
751 unsigned int mpic_irq_get_priority(unsigned int irq)
752 {
753 	int is_ipi;
754 	struct mpic *mpic = mpic_find(irq, &is_ipi);
755 	unsigned long flags;
756 	u32 reg;
757 
758 	spin_lock_irqsave(&mpic_lock, flags);
759 	if (is_ipi)
760 		reg = mpic_ipi_read(irq - mpic->ipi_offset);
761 	else
762 		reg = mpic_irq_read(irq - mpic->irq_offset, MPIC_IRQ_VECTOR_PRI);
763 	spin_unlock_irqrestore(&mpic_lock, flags);
764 	return (reg & MPIC_VECPRI_PRIORITY_MASK) >> MPIC_VECPRI_PRIORITY_SHIFT;
765 }
766 
767 void mpic_setup_this_cpu(void)
768 {
769 #ifdef CONFIG_SMP
770 	struct mpic *mpic = mpic_primary;
771 	unsigned long flags;
772 	u32 msk = 1 << hard_smp_processor_id();
773 	unsigned int i;
774 
775 	BUG_ON(mpic == NULL);
776 
777 	DBG("%s: setup_this_cpu(%d)\n", mpic->name, hard_smp_processor_id());
778 
779 	spin_lock_irqsave(&mpic_lock, flags);
780 
781  	/* let the mpic know we want intrs. default affinity is 0xffffffff
782 	 * until changed via /proc. That's how it's done on x86. If we want
783 	 * it differently, then we should make sure we also change the default
784 	 * values of irq_affinity in irq.c.
785  	 */
786 	if (distribute_irqs) {
787 	 	for (i = 0; i < mpic->num_sources ; i++)
788 			mpic_irq_write(i, MPIC_IRQ_DESTINATION,
789 				mpic_irq_read(i, MPIC_IRQ_DESTINATION) | msk);
790 	}
791 
792 	/* Set current processor priority to 0 */
793 	mpic_cpu_write(MPIC_CPU_CURRENT_TASK_PRI, 0);
794 
795 	spin_unlock_irqrestore(&mpic_lock, flags);
796 #endif /* CONFIG_SMP */
797 }
798 
799 int mpic_cpu_get_priority(void)
800 {
801 	struct mpic *mpic = mpic_primary;
802 
803 	return mpic_cpu_read(MPIC_CPU_CURRENT_TASK_PRI);
804 }
805 
806 void mpic_cpu_set_priority(int prio)
807 {
808 	struct mpic *mpic = mpic_primary;
809 
810 	prio &= MPIC_CPU_TASKPRI_MASK;
811 	mpic_cpu_write(MPIC_CPU_CURRENT_TASK_PRI, prio);
812 }
813 
814 /*
815  * XXX: someone who knows mpic should check this.
816  * do we need to eoi the ipi including for kexec cpu here (see xics comments)?
817  * or can we reset the mpic in the new kernel?
818  */
819 void mpic_teardown_this_cpu(int secondary)
820 {
821 	struct mpic *mpic = mpic_primary;
822 	unsigned long flags;
823 	u32 msk = 1 << hard_smp_processor_id();
824 	unsigned int i;
825 
826 	BUG_ON(mpic == NULL);
827 
828 	DBG("%s: teardown_this_cpu(%d)\n", mpic->name, hard_smp_processor_id());
829 	spin_lock_irqsave(&mpic_lock, flags);
830 
831 	/* let the mpic know we don't want intrs.  */
832 	for (i = 0; i < mpic->num_sources ; i++)
833 		mpic_irq_write(i, MPIC_IRQ_DESTINATION,
834 			mpic_irq_read(i, MPIC_IRQ_DESTINATION) & ~msk);
835 
836 	/* Set current processor priority to max */
837 	mpic_cpu_write(MPIC_CPU_CURRENT_TASK_PRI, 0xf);
838 
839 	spin_unlock_irqrestore(&mpic_lock, flags);
840 }
841 
842 
843 void mpic_send_ipi(unsigned int ipi_no, unsigned int cpu_mask)
844 {
845 	struct mpic *mpic = mpic_primary;
846 
847 	BUG_ON(mpic == NULL);
848 
849 	DBG("%s: send_ipi(ipi_no: %d)\n", mpic->name, ipi_no);
850 
851 	mpic_cpu_write(MPIC_CPU_IPI_DISPATCH_0 + ipi_no * 0x10,
852 		       mpic_physmask(cpu_mask & cpus_addr(cpu_online_map)[0]));
853 }
854 
855 int mpic_get_one_irq(struct mpic *mpic, struct pt_regs *regs)
856 {
857 	u32 irq;
858 
859 	irq = mpic_cpu_read(MPIC_CPU_INTACK) & MPIC_VECPRI_VECTOR_MASK;
860 	DBG("%s: get_one_irq(): %d\n", mpic->name, irq);
861 
862 	if (mpic->cascade && irq == mpic->cascade_vec) {
863 		DBG("%s: cascading ...\n", mpic->name);
864 		irq = mpic->cascade(regs, mpic->cascade_data);
865 		mpic_eoi(mpic);
866 		return irq;
867 	}
868 	if (unlikely(irq == MPIC_VEC_SPURRIOUS))
869 		return -1;
870 	if (irq < MPIC_VEC_IPI_0)
871 		return irq + mpic->irq_offset;
872        	DBG("%s: ipi %d !\n", mpic->name, irq - MPIC_VEC_IPI_0);
873 	return irq - MPIC_VEC_IPI_0 + mpic->ipi_offset;
874 }
875 
876 int mpic_get_irq(struct pt_regs *regs)
877 {
878 	struct mpic *mpic = mpic_primary;
879 
880 	BUG_ON(mpic == NULL);
881 
882 	return mpic_get_one_irq(mpic, regs);
883 }
884 
885 
886 #ifdef CONFIG_SMP
887 void mpic_request_ipis(void)
888 {
889 	struct mpic *mpic = mpic_primary;
890 
891 	BUG_ON(mpic == NULL);
892 
893 	printk("requesting IPIs ... \n");
894 
895 	/* IPIs are marked SA_INTERRUPT as they must run with irqs disabled */
896 	request_irq(mpic->ipi_offset+0, mpic_ipi_action, SA_INTERRUPT,
897 		    "IPI0 (call function)", mpic);
898 	request_irq(mpic->ipi_offset+1, mpic_ipi_action, SA_INTERRUPT,
899 		   "IPI1 (reschedule)", mpic);
900 	request_irq(mpic->ipi_offset+2, mpic_ipi_action, SA_INTERRUPT,
901 		   "IPI2 (unused)", mpic);
902 	request_irq(mpic->ipi_offset+3, mpic_ipi_action, SA_INTERRUPT,
903 		   "IPI3 (debugger break)", mpic);
904 
905 	printk("IPIs requested... \n");
906 }
907 
908 void smp_mpic_message_pass(int target, int msg)
909 {
910 	/* make sure we're sending something that translates to an IPI */
911 	if ((unsigned int)msg > 3) {
912 		printk("SMP %d: smp_message_pass: unknown msg %d\n",
913 		       smp_processor_id(), msg);
914 		return;
915 	}
916 	switch (target) {
917 	case MSG_ALL:
918 		mpic_send_ipi(msg, 0xffffffff);
919 		break;
920 	case MSG_ALL_BUT_SELF:
921 		mpic_send_ipi(msg, 0xffffffff & ~(1 << smp_processor_id()));
922 		break;
923 	default:
924 		mpic_send_ipi(msg, 1 << target);
925 		break;
926 	}
927 }
928 #endif /* CONFIG_SMP */
929