xref: /netbsd-src/sys/arch/xen/x86/xen_intr.c (revision e6c7e151de239c49d2e38720a061ed9d1fa99309)
1 /*	$NetBSD: xen_intr.c,v 1.18 2019/12/23 13:35:37 thorpej Exp $	*/
2 
3 /*-
4  * Copyright (c) 1998, 2001 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Charles M. Hannum, and by Jason R. Thorpe.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: xen_intr.c,v 1.18 2019/12/23 13:35:37 thorpej Exp $");
34 
35 #include <sys/param.h>
36 #include <sys/kernel.h>
37 #include <sys/kmem.h>
38 
39 #include <sys/cpu.h>
40 
41 #include <xen/evtchn.h>
42 #include <xen/xenfunc.h>
43 
44 #include <uvm/uvm.h>
45 
46 #include <machine/cpu.h>
47 #include <machine/intr.h>
48 
49 #include "acpica.h"
50 #include "ioapic.h"
51 #include "lapic.h"
52 #include "pci.h"
53 
54 #if NACPICA > 0
55 #include <dev/acpi/acpivar.h>
56 #endif
57 
58 #if NIOAPIC > 0 || NACPICA > 0
59 #include <machine/i82093var.h>
60 #endif
61 
62 #if NLAPIC > 0
63 #include <machine/i82489var.h>
64 #endif
65 
66 #if NPCI > 0
67 #include <dev/pci/ppbreg.h>
68 #endif
69 
70 /*
71  * Restore a value to cpl (unmasking interrupts).  If any unmasked
72  * interrupts are pending, call Xspllower() to process them.
73  */
74 void xen_spllower(int nlevel);
75 
76 void
77 xen_spllower(int nlevel)
78 {
79 	struct cpu_info *ci = curcpu();
80 	uint32_t xmask;
81 	u_long psl;
82 
83 	if (ci->ci_ilevel <= nlevel)
84 		return;
85 
86 	__insn_barrier();
87 
88 	xmask = XUNMASK(ci, nlevel);
89 	psl = xen_read_psl();
90 	x86_disable_intr();
91 	if (ci->ci_xpending & xmask) {
92 		KASSERT(psl == 0);
93 		Xspllower(nlevel);
94 		/* Xspllower does enable_intr() */
95 	} else {
96 		ci->ci_ilevel = nlevel;
97 		xen_write_psl(psl);
98 	}
99 }
100 
101 
102 #if !defined(XENPVHVM)
103 void
104 x86_disable_intr(void)
105 {
106 	curcpu()->ci_vcpu->evtchn_upcall_mask = 1;
107 	x86_lfence();
108 }
109 
110 void
111 x86_enable_intr(void)
112 {
113 	volatile struct vcpu_info *_vci = curcpu()->ci_vcpu;
114 	__insn_barrier();
115 	_vci->evtchn_upcall_mask = 0;
116 	x86_lfence(); /* unmask then check (avoid races) */
117 	if (__predict_false(_vci->evtchn_upcall_pending))
118 		hypervisor_force_callback();
119 }
120 
121 #endif /* !XENPVHVM */
122 
123 u_long
124 xen_read_psl(void)
125 {
126 
127 	return (curcpu()->ci_vcpu->evtchn_upcall_mask);
128 }
129 
130 void
131 xen_write_psl(u_long psl)
132 {
133 	struct cpu_info *ci = curcpu();
134 
135 	ci->ci_vcpu->evtchn_upcall_mask = psl;
136 	xen_rmb();
137 	if (ci->ci_vcpu->evtchn_upcall_pending && psl == 0) {
138 	    	hypervisor_force_callback();
139 	}
140 }
141 
142 void *
143 xen_intr_establish(int legacy_irq, struct pic *pic, int pin,
144     int type, int level, int (*handler)(void *), void *arg,
145     bool known_mpsafe)
146 {
147 
148 	return xen_intr_establish_xname(legacy_irq, pic, pin, type, level,
149 	    handler, arg, known_mpsafe, "XEN");
150 }
151 
152 void *
153 xen_intr_establish_xname(int legacy_irq, struct pic *pic, int pin,
154     int type, int level, int (*handler)(void *), void *arg,
155     bool known_mpsafe, const char *xname)
156 {
157 	const char *intrstr;
158 	char intrstr_buf[INTRIDBUF];
159 
160 	if (pic->pic_type == PIC_XEN) {
161 		struct intrhand *rih;
162 
163 		/*
164 		 * event_set_handler interprets `level != IPL_VM' to
165 		 * mean MP-safe, so we require the caller to match that
166 		 * for the moment.
167 		 */
168 		KASSERT(known_mpsafe == (level != IPL_VM));
169 
170 		intrstr = intr_create_intrid(legacy_irq, pic, pin, intrstr_buf,
171 		    sizeof(intrstr_buf));
172 
173 		event_set_handler(pin, handler, arg, level, intrstr, xname);
174 
175 		rih = kmem_zalloc(sizeof(*rih), cold ? KM_NOSLEEP : KM_SLEEP);
176 		if (rih == NULL) {
177 			printf("%s: can't allocate handler info\n", __func__);
178 			return NULL;
179 		}
180 
181 		/*
182 		 * XXX:
183 		 * This is just a copy for API conformance.
184 		 * The real ih is lost in the innards of
185 		 * event_set_handler(); where the details of
186 		 * biglock_wrapper etc are taken care of.
187 		 * All that goes away when we nuke event_set_handler()
188 		 * et. al. and unify with x86/intr.c
189 		 */
190 		rih->ih_pin = pin; /* port */
191 		rih->ih_fun = rih->ih_realfun = handler;
192 		rih->ih_arg = rih->ih_realarg = arg;
193 		rih->pic_type = pic->pic_type;
194 		return rih;
195 	} 	/* Else we assume pintr */
196 
197 #if (NPCI > 0 || NISA > 0) && defined(XENPV) /* XXX: support PVHVM pirq */
198 	struct pintrhand *pih;
199 	int gsi;
200 	int vector, evtchn;
201 
202 	KASSERTMSG(legacy_irq == -1 || (0 <= legacy_irq && legacy_irq < NUM_XEN_IRQS),
203 	    "bad legacy IRQ value: %d", legacy_irq);
204 	KASSERTMSG(!(legacy_irq == -1 && pic == &i8259_pic),
205 	    "non-legacy IRQon i8259 ");
206 
207 	gsi = xen_pic_to_gsi(pic, pin);
208 
209 	intrstr = intr_create_intrid(gsi, pic, pin, intrstr_buf,
210 	    sizeof(intrstr_buf));
211 
212 	vector = xen_vec_alloc(gsi);
213 
214 	if (irq2port[gsi] == 0) {
215 		extern struct cpu_info phycpu_info_primary; /* XXX */
216 		struct cpu_info *ci = &phycpu_info_primary;
217 
218 		pic->pic_addroute(pic, ci, pin, vector, type);
219 
220 		evtchn = bind_pirq_to_evtch(gsi);
221 		KASSERT(evtchn > 0);
222 		KASSERT(evtchn < NR_EVENT_CHANNELS);
223 		irq2port[gsi] = evtchn + 1;
224 		xen_atomic_set_bit(&ci->ci_evtmask[0], evtchn);
225 	} else {
226 		/*
227 		 * Shared interrupt - we can't rebind.
228 		 * The port is shared instead.
229 		 */
230 		evtchn = irq2port[gsi] - 1;
231 	}
232 
233 	pih = pirq_establish(gsi, evtchn, handler, arg, level,
234 			     intrstr, xname);
235 	pih->pic_type = pic->pic_type;
236 	return pih;
237 #endif /* NPCI > 0 || NISA > 0 */
238 
239 	/* FALLTHROUGH */
240 	return NULL;
241 }
242 
243 /*
244  * Mask an interrupt source.
245  */
246 void
247 xen_intr_mask(struct intrhand *ih)
248 {
249 	/* XXX */
250 	panic("xen_intr_mask: not yet implemented.");
251 }
252 
253 /*
254  * Unmask an interrupt source.
255  */
256 void
257 xen_intr_unmask(struct intrhand *ih)
258 {
259 	/* XXX */
260 	panic("xen_intr_unmask: not yet implemented.");
261 }
262 
263 /*
264  * Deregister an interrupt handler.
265  */
266 void
267 xen_intr_disestablish(struct intrhand *ih)
268 {
269 
270 	if (ih->pic_type == PIC_XEN) {
271 		event_remove_handler(ih->ih_pin, ih->ih_realfun,
272 		    ih->ih_realarg);
273 		kmem_free(ih, sizeof(*ih));
274 		return;
275 	}
276 #if defined(DOM0OPS)
277 	/*
278 	 * Cache state, to prevent a use after free situation with
279 	 * ih.
280 	 */
281 
282 	struct pintrhand *pih = (struct pintrhand *)ih;
283 
284 	int pirq = pih->pirq;
285 	int port = pih->evtch;
286 	KASSERT(irq2port[pirq] != 0);
287 
288 	pirq_disestablish(pih);
289 
290 	if (evtsource[port] == NULL) {
291 			/*
292 			 * Last handler was removed by
293 			 * event_remove_handler().
294 			 *
295 			 * We can safely unbind the pirq now.
296 			 */
297 
298 			port = unbind_pirq_from_evtch(pirq);
299 			KASSERT(port == pih->evtch);
300 			irq2port[pirq] = 0;
301 	}
302 #endif
303 	return;
304 }
305 
306 /* MI interface for kern_cpu.c */
307 void xen_cpu_intr_redistribute(void);
308 
309 void
310 xen_cpu_intr_redistribute(void)
311 {
312 	KASSERT(mutex_owned(&cpu_lock));
313 	KASSERT(mp_online);
314 
315 	return;
316 }
317 
318 /* MD - called by x86/cpu.c */
319 #if defined(INTRSTACKSIZE)
320 static inline bool
321 redzone_const_or_false(bool x)
322 {
323 #ifdef DIAGNOSTIC
324 	return x;
325 #else
326 	return false;
327 #endif /* !DIAGNOSTIC */
328 }
329 
330 static inline int
331 redzone_const_or_zero(int x)
332 {
333 	return redzone_const_or_false(true) ? x : 0;
334 }
335 #endif
336 
337 void xen_cpu_intr_init(struct cpu_info *);
338 void
339 xen_cpu_intr_init(struct cpu_info *ci)
340 {
341 	int i; /* XXX: duplicate */
342 
343 	ci->ci_xunmask[0] = 0xfffffffe;
344 	for (i = 1; i < NIPL; i++)
345 		ci->ci_xunmask[i] = ci->ci_xunmask[i - 1] & ~(1 << i);
346 
347 #if defined(INTRSTACKSIZE)
348 	vaddr_t istack;
349 
350 	/*
351 	 * If the red zone is activated, protect both the top and
352 	 * the bottom of the stack with an unmapped page.
353 	 */
354 	istack = uvm_km_alloc(kernel_map,
355 	    INTRSTACKSIZE + redzone_const_or_zero(2 * PAGE_SIZE), 0,
356 	    UVM_KMF_WIRED|UVM_KMF_ZERO);
357 	if (redzone_const_or_false(true)) {
358 		pmap_kremove(istack, PAGE_SIZE);
359 		pmap_kremove(istack + INTRSTACKSIZE + PAGE_SIZE, PAGE_SIZE);
360 		pmap_update(pmap_kernel());
361 	}
362 
363 	/*
364 	 * 33 used to be 1.  Arbitrarily reserve 32 more register_t's
365 	 * of space for ddb(4) to examine some subroutine arguments
366 	 * and to hunt for the next stack frame.
367 	 */
368 	ci->ci_intrstack = (char *)istack + redzone_const_or_zero(PAGE_SIZE) +
369 	    INTRSTACKSIZE - 33 * sizeof(register_t);
370 #endif
371 
372 	ci->ci_idepth = -1;
373 }
374 
375 /*
376  * Everything below from here is duplicated from x86/intr.c
377  * When intr.c and xen_intr.c are unified, these will need to be
378  * merged.
379  */
380 
381 u_int xen_cpu_intr_count(struct cpu_info *ci);
382 
383 u_int
384 xen_cpu_intr_count(struct cpu_info *ci)
385 {
386 
387 	KASSERT(ci->ci_nintrhand >= 0);
388 
389 	return ci->ci_nintrhand;
390 }
391 
392 static const char *
393 xen_intr_string(int port, char *buf, size_t len, struct pic *pic)
394 {
395 	KASSERT(pic->pic_type == PIC_XEN);
396 
397 	KASSERT(port >= 0);
398 	KASSERT(port < NR_EVENT_CHANNELS);
399 
400 	snprintf(buf, len, "%s channel %d", pic->pic_name, port);
401 
402 	return buf;
403 }
404 
405 static const char *
406 legacy_intr_string(int ih, char *buf, size_t len, struct pic *pic)
407 {
408 	int legacy_irq;
409 
410 	KASSERT(pic->pic_type == PIC_I8259);
411 #if NLAPIC > 0
412 	KASSERT(APIC_IRQ_ISLEGACY(ih));
413 
414 	legacy_irq = APIC_IRQ_LEGACY_IRQ(ih);
415 #else
416 	legacy_irq = ih;
417 #endif
418 	KASSERT(legacy_irq >= 0 && legacy_irq < 16);
419 
420 	snprintf(buf, len, "%s pin %d", pic->pic_name, legacy_irq);
421 
422 	return buf;
423 }
424 
425 const char * xintr_string(intr_handle_t ih, char *buf, size_t len);
426 
427 const char *
428 xintr_string(intr_handle_t ih, char *buf, size_t len)
429 {
430 #if NIOAPIC > 0
431 	struct ioapic_softc *pic;
432 #endif
433 
434 	if (ih == 0)
435 		panic("%s: bogus handle 0x%" PRIx64, __func__, ih);
436 
437 #if NIOAPIC > 0
438 	if (ih & APIC_INT_VIA_APIC) {
439 		pic = ioapic_find(APIC_IRQ_APIC(ih));
440 		if (pic != NULL) {
441 			snprintf(buf, len, "%s pin %d",
442 			    device_xname(pic->sc_dev), APIC_IRQ_PIN(ih));
443 		} else {
444 			snprintf(buf, len,
445 			    "apic %d int %d (irq %d)",
446 			    APIC_IRQ_APIC(ih),
447 			    APIC_IRQ_PIN(ih),
448 			    APIC_IRQ_LEGACY_IRQ(ih));
449 		}
450 	} else
451 		snprintf(buf, len, "irq %d", APIC_IRQ_LEGACY_IRQ(ih));
452 
453 #elif NLAPIC > 0
454 	snprintf(buf, len, "irq %d", APIC_IRQ_LEGACY_IRQ(ih));
455 #else
456 	snprintf(buf, len, "irq %d", (int) ih);
457 #endif
458 	return buf;
459 
460 }
461 
462 /*
463  * Create an interrupt id such as "ioapic0 pin 9". This interrupt id is used
464  * by MI code and intrctl(8).
465  */
466 const char * xen_intr_create_intrid(int legacy_irq, struct pic *pic,
467     int pin, char *buf, size_t len);
468 
469 const char *
470 xen_intr_create_intrid(int legacy_irq, struct pic *pic, int pin, char *buf, size_t len)
471 {
472 	int ih = 0;
473 
474 #if NPCI > 0
475 #if defined(__HAVE_PCI_MSI_MSIX)
476 	if ((pic->pic_type == PIC_MSI) || (pic->pic_type == PIC_MSIX)) {
477 		uint64_t pih;
478 		int dev, vec;
479 
480 		dev = msipic_get_devid(pic);
481 		vec = pin;
482 		pih = __SHIFTIN((uint64_t)dev, MSI_INT_DEV_MASK)
483 			| __SHIFTIN((uint64_t)vec, MSI_INT_VEC_MASK)
484 			| APIC_INT_VIA_MSI;
485 		if (pic->pic_type == PIC_MSI)
486 			MSI_INT_MAKE_MSI(pih);
487 		else if (pic->pic_type == PIC_MSIX)
488 			MSI_INT_MAKE_MSIX(pih);
489 
490 		return x86_pci_msi_string(NULL, pih, buf, len);
491 	}
492 #endif /* __HAVE_PCI_MSI_MSIX */
493 #endif
494 
495 	if (pic->pic_type == PIC_XEN) {
496 		ih = pin;	/* Port == pin */
497 		return xen_intr_string(pin, buf, len, pic);
498 	}
499 
500 	/*
501 	 * If the device is pci, "legacy_irq" is alway -1. Least 8 bit of "ih"
502 	 * is only used in intr_string() to show the irq number.
503 	 * If the device is "legacy"(such as floppy), it should not use
504 	 * intr_string().
505 	 */
506 	if (pic->pic_type == PIC_I8259) {
507 		ih = legacy_irq;
508 		return legacy_intr_string(ih, buf, len, pic);
509 	}
510 
511 #if NIOAPIC > 0 || NACPICA > 0
512 	ih = ((pic->pic_apicid << APIC_INT_APIC_SHIFT) & APIC_INT_APIC_MASK)
513 	    | ((pin << APIC_INT_PIN_SHIFT) & APIC_INT_PIN_MASK);
514 	if (pic->pic_type == PIC_IOAPIC) {
515 		ih |= APIC_INT_VIA_APIC;
516 	}
517 	ih |= pin;
518 	return intr_string(ih, buf, len);
519 #endif
520 
521 	return NULL; /* No pic found! */
522 }
523 
524 #if !defined(XENPVHVM)
525 __strong_alias(spllower, xen_spllower);
526 __strong_alias(x86_read_psl, xen_read_psl);
527 __strong_alias(x86_write_psl, xen_write_psl);
528 
529 __strong_alias(intr_string, xintr_string);
530 __strong_alias(intr_create_intrid, xen_intr_create_intrid);
531 __strong_alias(intr_establish, xen_intr_establish);
532 __strong_alias(intr_establish_xname, xen_intr_establish_xname);
533 __strong_alias(intr_mask, xen_intr_mask);
534 __strong_alias(intr_unmask, xen_intr_unmask);
535 __strong_alias(intr_disestablish, xen_intr_disestablish);
536 __strong_alias(cpu_intr_redistribute, xen_cpu_intr_redistribute);
537 __strong_alias(cpu_intr_count, xen_cpu_intr_count);
538 __strong_alias(cpu_intr_init, xen_cpu_intr_init);
539 #endif /* !XENPVHVM */
540