xref: /netbsd-src/sys/arch/xen/x86/xen_intr.c (revision 7330f729ccf0bd976a06f95fad452fe774fc7fd1)
1 /*	$NetBSD: xen_intr.c,v 1.17 2019/06/07 12:43:52 cherry 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 1.17 2019/06/07 12:43:52 cherry 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  * Deregister an interrupt handler.
245  */
246 void
247 xen_intr_disestablish(struct intrhand *ih)
248 {
249 
250 	if (ih->pic_type == PIC_XEN) {
251 		event_remove_handler(ih->ih_pin, ih->ih_realfun,
252 		    ih->ih_realarg);
253 		kmem_free(ih, sizeof(*ih));
254 		return;
255 	}
256 #if defined(DOM0OPS)
257 	/*
258 	 * Cache state, to prevent a use after free situation with
259 	 * ih.
260 	 */
261 
262 	struct pintrhand *pih = (struct pintrhand *)ih;
263 
264 	int pirq = pih->pirq;
265 	int port = pih->evtch;
266 	KASSERT(irq2port[pirq] != 0);
267 
268 	pirq_disestablish(pih);
269 
270 	if (evtsource[port] == NULL) {
271 			/*
272 			 * Last handler was removed by
273 			 * event_remove_handler().
274 			 *
275 			 * We can safely unbind the pirq now.
276 			 */
277 
278 			port = unbind_pirq_from_evtch(pirq);
279 			KASSERT(port == pih->evtch);
280 			irq2port[pirq] = 0;
281 	}
282 #endif
283 	return;
284 }
285 
286 /* MI interface for kern_cpu.c */
287 void xen_cpu_intr_redistribute(void);
288 
289 void
290 xen_cpu_intr_redistribute(void)
291 {
292 	KASSERT(mutex_owned(&cpu_lock));
293 	KASSERT(mp_online);
294 
295 	return;
296 }
297 
298 /* MD - called by x86/cpu.c */
299 #if defined(INTRSTACKSIZE)
300 static inline bool
301 redzone_const_or_false(bool x)
302 {
303 #ifdef DIAGNOSTIC
304 	return x;
305 #else
306 	return false;
307 #endif /* !DIAGNOSTIC */
308 }
309 
310 static inline int
311 redzone_const_or_zero(int x)
312 {
313 	return redzone_const_or_false(true) ? x : 0;
314 }
315 #endif
316 
317 void xen_cpu_intr_init(struct cpu_info *);
318 void
319 xen_cpu_intr_init(struct cpu_info *ci)
320 {
321 	int i; /* XXX: duplicate */
322 
323 	ci->ci_xunmask[0] = 0xfffffffe;
324 	for (i = 1; i < NIPL; i++)
325 		ci->ci_xunmask[i] = ci->ci_xunmask[i - 1] & ~(1 << i);
326 
327 #if defined(INTRSTACKSIZE)
328 	vaddr_t istack;
329 
330 	/*
331 	 * If the red zone is activated, protect both the top and
332 	 * the bottom of the stack with an unmapped page.
333 	 */
334 	istack = uvm_km_alloc(kernel_map,
335 	    INTRSTACKSIZE + redzone_const_or_zero(2 * PAGE_SIZE), 0,
336 	    UVM_KMF_WIRED|UVM_KMF_ZERO);
337 	if (redzone_const_or_false(true)) {
338 		pmap_kremove(istack, PAGE_SIZE);
339 		pmap_kremove(istack + INTRSTACKSIZE + PAGE_SIZE, PAGE_SIZE);
340 		pmap_update(pmap_kernel());
341 	}
342 
343 	/*
344 	 * 33 used to be 1.  Arbitrarily reserve 32 more register_t's
345 	 * of space for ddb(4) to examine some subroutine arguments
346 	 * and to hunt for the next stack frame.
347 	 */
348 	ci->ci_intrstack = (char *)istack + redzone_const_or_zero(PAGE_SIZE) +
349 	    INTRSTACKSIZE - 33 * sizeof(register_t);
350 #endif
351 
352 	ci->ci_idepth = -1;
353 }
354 
355 /*
356  * Everything below from here is duplicated from x86/intr.c
357  * When intr.c and xen_intr.c are unified, these will need to be
358  * merged.
359  */
360 
361 u_int xen_cpu_intr_count(struct cpu_info *ci);
362 
363 u_int
364 xen_cpu_intr_count(struct cpu_info *ci)
365 {
366 
367 	KASSERT(ci->ci_nintrhand >= 0);
368 
369 	return ci->ci_nintrhand;
370 }
371 
372 static const char *
373 xen_intr_string(int port, char *buf, size_t len, struct pic *pic)
374 {
375 	KASSERT(pic->pic_type == PIC_XEN);
376 
377 	KASSERT(port >= 0);
378 	KASSERT(port < NR_EVENT_CHANNELS);
379 
380 	snprintf(buf, len, "%s channel %d", pic->pic_name, port);
381 
382 	return buf;
383 }
384 
385 static const char *
386 legacy_intr_string(int ih, char *buf, size_t len, struct pic *pic)
387 {
388 	int legacy_irq;
389 
390 	KASSERT(pic->pic_type == PIC_I8259);
391 #if NLAPIC > 0
392 	KASSERT(APIC_IRQ_ISLEGACY(ih));
393 
394 	legacy_irq = APIC_IRQ_LEGACY_IRQ(ih);
395 #else
396 	legacy_irq = ih;
397 #endif
398 	KASSERT(legacy_irq >= 0 && legacy_irq < 16);
399 
400 	snprintf(buf, len, "%s pin %d", pic->pic_name, legacy_irq);
401 
402 	return buf;
403 }
404 
405 const char * xintr_string(intr_handle_t ih, char *buf, size_t len);
406 
407 const char *
408 xintr_string(intr_handle_t ih, char *buf, size_t len)
409 {
410 #if NIOAPIC > 0
411 	struct ioapic_softc *pic;
412 #endif
413 
414 	if (ih == 0)
415 		panic("%s: bogus handle 0x%" PRIx64, __func__, ih);
416 
417 #if NIOAPIC > 0
418 	if (ih & APIC_INT_VIA_APIC) {
419 		pic = ioapic_find(APIC_IRQ_APIC(ih));
420 		if (pic != NULL) {
421 			snprintf(buf, len, "%s pin %d",
422 			    device_xname(pic->sc_dev), APIC_IRQ_PIN(ih));
423 		} else {
424 			snprintf(buf, len,
425 			    "apic %d int %d (irq %d)",
426 			    APIC_IRQ_APIC(ih),
427 			    APIC_IRQ_PIN(ih),
428 			    APIC_IRQ_LEGACY_IRQ(ih));
429 		}
430 	} else
431 		snprintf(buf, len, "irq %d", APIC_IRQ_LEGACY_IRQ(ih));
432 
433 #elif NLAPIC > 0
434 	snprintf(buf, len, "irq %d", APIC_IRQ_LEGACY_IRQ(ih));
435 #else
436 	snprintf(buf, len, "irq %d", (int) ih);
437 #endif
438 	return buf;
439 
440 }
441 
442 /*
443  * Create an interrupt id such as "ioapic0 pin 9". This interrupt id is used
444  * by MI code and intrctl(8).
445  */
446 const char * xen_intr_create_intrid(int legacy_irq, struct pic *pic,
447     int pin, char *buf, size_t len);
448 
449 const char *
450 xen_intr_create_intrid(int legacy_irq, struct pic *pic, int pin, char *buf, size_t len)
451 {
452 	int ih = 0;
453 
454 #if NPCI > 0
455 #if defined(__HAVE_PCI_MSI_MSIX)
456 	if ((pic->pic_type == PIC_MSI) || (pic->pic_type == PIC_MSIX)) {
457 		uint64_t pih;
458 		int dev, vec;
459 
460 		dev = msipic_get_devid(pic);
461 		vec = pin;
462 		pih = __SHIFTIN((uint64_t)dev, MSI_INT_DEV_MASK)
463 			| __SHIFTIN((uint64_t)vec, MSI_INT_VEC_MASK)
464 			| APIC_INT_VIA_MSI;
465 		if (pic->pic_type == PIC_MSI)
466 			MSI_INT_MAKE_MSI(pih);
467 		else if (pic->pic_type == PIC_MSIX)
468 			MSI_INT_MAKE_MSIX(pih);
469 
470 		return x86_pci_msi_string(NULL, pih, buf, len);
471 	}
472 #endif /* __HAVE_PCI_MSI_MSIX */
473 #endif
474 
475 	if (pic->pic_type == PIC_XEN) {
476 		ih = pin;	/* Port == pin */
477 		return xen_intr_string(pin, buf, len, pic);
478 	}
479 
480 	/*
481 	 * If the device is pci, "legacy_irq" is alway -1. Least 8 bit of "ih"
482 	 * is only used in intr_string() to show the irq number.
483 	 * If the device is "legacy"(such as floppy), it should not use
484 	 * intr_string().
485 	 */
486 	if (pic->pic_type == PIC_I8259) {
487 		ih = legacy_irq;
488 		return legacy_intr_string(ih, buf, len, pic);
489 	}
490 
491 #if NIOAPIC > 0 || NACPICA > 0
492 	ih = ((pic->pic_apicid << APIC_INT_APIC_SHIFT) & APIC_INT_APIC_MASK)
493 	    | ((pin << APIC_INT_PIN_SHIFT) & APIC_INT_PIN_MASK);
494 	if (pic->pic_type == PIC_IOAPIC) {
495 		ih |= APIC_INT_VIA_APIC;
496 	}
497 	ih |= pin;
498 	return intr_string(ih, buf, len);
499 #endif
500 
501 	return NULL; /* No pic found! */
502 }
503 
504 #if !defined(XENPVHVM)
505 __strong_alias(spllower, xen_spllower);
506 __strong_alias(x86_read_psl, xen_read_psl);
507 __strong_alias(x86_write_psl, xen_write_psl);
508 
509 __strong_alias(intr_string, xintr_string);
510 __strong_alias(intr_create_intrid, xen_intr_create_intrid);
511 __strong_alias(intr_establish, xen_intr_establish);
512 __strong_alias(intr_establish_xname, xen_intr_establish_xname);
513 __strong_alias(intr_disestablish, xen_intr_disestablish);
514 __strong_alias(cpu_intr_redistribute, xen_cpu_intr_redistribute);
515 __strong_alias(cpu_intr_count, xen_cpu_intr_count);
516 __strong_alias(cpu_intr_init, xen_cpu_intr_init);
517 #endif /* !XENPVHVM */
518