xref: /illumos-gate/usr/src/cmd/bhyve/pci_irq.c (revision bf21cd93)
1 /*-
2  * Copyright (c) 2014 Advanced Computing Technologies LLC
3  * Written by: John H. Baldwin <jhb@FreeBSD.org>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD: head/usr.sbin/bhyve/pci_irq.c 266125 2014-05-15 14:16:55Z jhb $");
31 
32 #include <sys/param.h>
33 #include <machine/vmm.h>
34 
35 #include <assert.h>
36 #include <pthread.h>
37 #include <stdbool.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <vmmapi.h>
41 
42 #include "acpi.h"
43 #include "inout.h"
44 #include "pci_emul.h"
45 #include "pci_irq.h"
46 #include "pci_lpc.h"
47 
48 /*
49  * Implement an 8 pin PCI interrupt router compatible with the router
50  * present on Intel's ICH10 chip.
51  */
52 
53 /* Fields in each PIRQ register. */
54 #define	PIRQ_DIS	0x80
55 #define	PIRQ_IRQ	0x0f
56 
57 /* Only IRQs 3-7, 9-12, and 14-15 are permitted. */
58 #define	PERMITTED_IRQS	0xdef8
59 #define	IRQ_PERMITTED(irq)	(((1U << (irq)) & PERMITTED_IRQS) != 0)
60 
61 /* IRQ count to disable an IRQ. */
62 #define	IRQ_DISABLED	0xff
63 
64 static struct pirq {
65 	uint8_t	reg;
66 	int	use_count;
67 	int	active_count;
68 	pthread_mutex_t lock;
69 } pirqs[8];
70 
71 static u_char irq_counts[16];
72 static int pirq_cold = 1;
73 
74 /*
75  * Returns true if this pin is enabled with a valid IRQ.  Setting the
76  * register to a reserved IRQ causes interrupts to not be asserted as
77  * if the pin was disabled.
78  */
79 static bool
80 pirq_valid_irq(int reg)
81 {
82 
83 	if (reg & PIRQ_DIS)
84 		return (false);
85 	return (IRQ_PERMITTED(reg & PIRQ_IRQ));
86 }
87 
88 uint8_t
89 pirq_read(int pin)
90 {
91 
92 	assert(pin > 0 && pin <= nitems(pirqs));
93 	return (pirqs[pin - 1].reg);
94 }
95 
96 void
97 pirq_write(struct vmctx *ctx, int pin, uint8_t val)
98 {
99 	struct pirq *pirq;
100 
101 	assert(pin > 0 && pin <= nitems(pirqs));
102 	pirq = &pirqs[pin - 1];
103 	pthread_mutex_lock(&pirq->lock);
104 	if (pirq->reg != (val & (PIRQ_DIS | PIRQ_IRQ))) {
105 		if (pirq->active_count != 0 && pirq_valid_irq(pirq->reg))
106 			vm_isa_deassert_irq(ctx, pirq->reg & PIRQ_IRQ, -1);
107 		pirq->reg = val & (PIRQ_DIS | PIRQ_IRQ);
108 		if (pirq->active_count != 0 && pirq_valid_irq(pirq->reg))
109 			vm_isa_assert_irq(ctx, pirq->reg & PIRQ_IRQ, -1);
110 	}
111 	pthread_mutex_unlock(&pirq->lock);
112 }
113 
114 void
115 pci_irq_reserve(int irq)
116 {
117 
118 	assert(irq < nitems(irq_counts));
119 	assert(pirq_cold);
120 	assert(irq_counts[irq] == 0 || irq_counts[irq] == IRQ_DISABLED);
121 	irq_counts[irq] = IRQ_DISABLED;
122 }
123 
124 void
125 pci_irq_use(int irq)
126 {
127 
128 	assert(irq < nitems(irq_counts));
129 	assert(pirq_cold);
130 	if (irq_counts[irq] != IRQ_DISABLED)
131 		irq_counts[irq]++;
132 }
133 
134 void
135 pci_irq_init(struct vmctx *ctx)
136 {
137 	int i;
138 
139 	for (i = 0; i < nitems(pirqs); i++) {
140 		pirqs[i].reg = PIRQ_DIS;
141 		pirqs[i].use_count = 0;
142 		pirqs[i].active_count = 0;
143 		pthread_mutex_init(&pirqs[i].lock, NULL);
144 	}
145 	for (i = 0; i < nitems(irq_counts); i++) {
146 		if (IRQ_PERMITTED(i))
147 			irq_counts[i] = 0;
148 		else
149 			irq_counts[i] = IRQ_DISABLED;
150 	}
151 }
152 
153 void
154 pci_irq_assert(struct pci_devinst *pi)
155 {
156 	struct pirq *pirq;
157 
158 	if (pi->pi_lintr.pirq_pin > 0) {
159 		assert(pi->pi_lintr.pirq_pin <= nitems(pirqs));
160 		pirq = &pirqs[pi->pi_lintr.pirq_pin - 1];
161 		pthread_mutex_lock(&pirq->lock);
162 		pirq->active_count++;
163 		if (pirq->active_count == 1 && pirq_valid_irq(pirq->reg)) {
164 			vm_isa_assert_irq(pi->pi_vmctx, pirq->reg & PIRQ_IRQ,
165 			    pi->pi_lintr.ioapic_irq);
166 			pthread_mutex_unlock(&pirq->lock);
167 			return;
168 		}
169 		pthread_mutex_unlock(&pirq->lock);
170 	}
171 	vm_ioapic_assert_irq(pi->pi_vmctx, pi->pi_lintr.ioapic_irq);
172 }
173 
174 void
175 pci_irq_deassert(struct pci_devinst *pi)
176 {
177 	struct pirq *pirq;
178 
179 	if (pi->pi_lintr.pirq_pin > 0) {
180 		assert(pi->pi_lintr.pirq_pin <= nitems(pirqs));
181 		pirq = &pirqs[pi->pi_lintr.pirq_pin - 1];
182 		pthread_mutex_lock(&pirq->lock);
183 		pirq->active_count--;
184 		if (pirq->active_count == 0 && pirq_valid_irq(pirq->reg)) {
185 			vm_isa_deassert_irq(pi->pi_vmctx, pirq->reg & PIRQ_IRQ,
186 			    pi->pi_lintr.ioapic_irq);
187 			pthread_mutex_unlock(&pirq->lock);
188 			return;
189 		}
190 		pthread_mutex_unlock(&pirq->lock);
191 	}
192 	vm_ioapic_deassert_irq(pi->pi_vmctx, pi->pi_lintr.ioapic_irq);
193 }
194 
195 int
196 pirq_alloc_pin(struct vmctx *ctx)
197 {
198 	int best_count, best_irq, best_pin, irq, pin;
199 
200 	pirq_cold = 1;
201 
202 	/* First, find the least-used PIRQ pin. */
203 	best_pin = 0;
204 	best_count = pirqs[0].use_count;
205 	for (pin = 1; pin < nitems(pirqs); pin++) {
206 		if (pirqs[pin].use_count < best_count) {
207 			best_pin = pin;
208 			best_count = pirqs[pin].use_count;
209 		}
210 	}
211 	pirqs[best_pin].use_count++;
212 
213 	/* Second, route this pin to an IRQ. */
214 	if (pirqs[best_pin].reg == PIRQ_DIS) {
215 		best_irq = -1;
216 		best_count = 0;
217 		for (irq = 0; irq < nitems(irq_counts); irq++) {
218 			if (irq_counts[irq] == IRQ_DISABLED)
219 				continue;
220 			if (best_irq == -1 || irq_counts[irq] < best_count) {
221 				best_irq = irq;
222 				best_count = irq_counts[irq];
223 			}
224 		}
225 		assert(best_irq != 0);
226 		irq_counts[best_irq]++;
227 		pirqs[best_pin].reg = best_irq;
228 		vm_isa_set_irq_trigger(ctx, best_irq, LEVEL_TRIGGER);
229 	}
230 
231 	return (best_pin + 1);
232 }
233 
234 int
235 pirq_irq(int pin)
236 {
237 
238 	if (pin == -1)
239 		return (255);
240 	assert(pin > 0 && pin <= nitems(pirqs));
241 	return (pirqs[pin - 1].reg & PIRQ_IRQ);
242 }
243 
244 /* XXX: Generate $PIR table. */
245 
246 #ifdef	__FreeBSD__
247 static void
248 pirq_dsdt(void)
249 {
250 	char *irq_prs, *old;
251 	int irq, pin;
252 
253 	irq_prs = NULL;
254 	for (irq = 0; irq < nitems(irq_counts); irq++) {
255 		if (!IRQ_PERMITTED(irq))
256 			continue;
257 		if (irq_prs == NULL)
258 			asprintf(&irq_prs, "%d", irq);
259 		else {
260 			old = irq_prs;
261 			asprintf(&irq_prs, "%s,%d", old, irq);
262 			free(old);
263 		}
264 	}
265 
266 	/*
267 	 * A helper method to validate a link register's value.  This
268 	 * duplicates pirq_valid_irq().
269 	 */
270 	dsdt_line("");
271 	dsdt_line("Method (PIRV, 1, NotSerialized)");
272 	dsdt_line("{");
273 	dsdt_line("  If (And (Arg0, 0x%02X))", PIRQ_DIS);
274 	dsdt_line("  {");
275 	dsdt_line("    Return (0x00)");
276 	dsdt_line("  }");
277 	dsdt_line("  And (Arg0, 0x%02X, Local0)", PIRQ_IRQ);
278 	dsdt_line("  If (LLess (Local0, 0x03))");
279 	dsdt_line("  {");
280 	dsdt_line("    Return (0x00)");
281 	dsdt_line("  }");
282 	dsdt_line("  If (LEqual (Local0, 0x08))");
283 	dsdt_line("  {");
284 	dsdt_line("    Return (0x00)");
285 	dsdt_line("  }");
286 	dsdt_line("  If (LEqual (Local0, 0x0D))");
287 	dsdt_line("  {");
288 	dsdt_line("    Return (0x00)");
289 	dsdt_line("  }");
290 	dsdt_line("  Return (0x01)");
291 	dsdt_line("}");
292 
293 	for (pin = 0; pin < nitems(pirqs); pin++) {
294 		dsdt_line("");
295 		dsdt_line("Device (LNK%c)", 'A' + pin);
296 		dsdt_line("{");
297 		dsdt_line("  Name (_HID, EisaId (\"PNP0C0F\"))");
298 		dsdt_line("  Name (_UID, 0x%02X)", pin + 1);
299 		dsdt_line("  Method (_STA, 0, NotSerialized)");
300 		dsdt_line("  {");
301 		dsdt_line("    If (PIRV (PIR%c))", 'A' + pin);
302 		dsdt_line("    {");
303 		dsdt_line("       Return (0x0B)");
304 		dsdt_line("    }");
305 		dsdt_line("    Else");
306 		dsdt_line("    {");
307 		dsdt_line("       Return (0x09)");
308 		dsdt_line("    }");
309 		dsdt_line("  }");
310 		dsdt_line("  Name (_PRS, ResourceTemplate ()");
311 		dsdt_line("  {");
312 		dsdt_line("    IRQ (Level, ActiveLow, Shared, )");
313 		dsdt_line("      {%s}", irq_prs);
314 		dsdt_line("  })");
315 		dsdt_line("  Name (CB%02X, ResourceTemplate ()", pin + 1);
316 		dsdt_line("  {");
317 		dsdt_line("    IRQ (Level, ActiveLow, Shared, )");
318 		dsdt_line("      {}");
319 		dsdt_line("  })");
320 		dsdt_line("  CreateWordField (CB%02X, 0x01, CIR%c)",
321 		    pin + 1, 'A' + pin);
322 		dsdt_line("  Method (_CRS, 0, NotSerialized)");
323 		dsdt_line("  {");
324 		dsdt_line("    And (PIR%c, 0x%02X, Local0)", 'A' + pin,
325 		    PIRQ_DIS | PIRQ_IRQ);
326 		dsdt_line("    If (PIRV (Local0))");
327 		dsdt_line("    {");
328 		dsdt_line("      ShiftLeft (0x01, Local0, CIR%c)", 'A' + pin);
329 		dsdt_line("    }");
330 		dsdt_line("    Else");
331 		dsdt_line("    {");
332 		dsdt_line("      Store (0x00, CIR%c)", 'A' + pin);
333 		dsdt_line("    }");
334 		dsdt_line("    Return (CB%02X)", pin + 1);
335 		dsdt_line("  }");
336 		dsdt_line("  Method (_DIS, 0, NotSerialized)");
337 		dsdt_line("  {");
338 		dsdt_line("    Store (0x80, PIR%c)", 'A' + pin);
339 		dsdt_line("  }");
340 		dsdt_line("  Method (_SRS, 1, NotSerialized)");
341 		dsdt_line("  {");
342 		dsdt_line("    CreateWordField (Arg0, 0x01, SIR%c)", 'A' + pin);
343 		dsdt_line("    FindSetRightBit (SIR%c, Local0)", 'A' + pin);
344 		dsdt_line("    Store (Decrement (Local0), PIR%c)", 'A' + pin);
345 		dsdt_line("  }");
346 		dsdt_line("}");
347 	}
348 	free(irq_prs);
349 }
350 LPC_DSDT(pirq_dsdt);
351 #endif
352