1 /*
2 * pci_irq.c - ACPI PCI Interrupt Routing ($Revision: 11 $)
3 *
4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6 * Copyright (C) 2002 Dominik Brodowski <devel@brodo.de>
7 *
8 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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 of the License, or (at
13 * your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License along
21 * with this program; if not, write to the Free Software Foundation, Inc.,
22 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
23 *
24 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
25 */
26
27 #include <linux/config.h>
28
29 #include <linux/kernel.h>
30 #include <linux/module.h>
31 #include <linux/init.h>
32 #include <linux/types.h>
33 #include <linux/proc_fs.h>
34 #include <linux/spinlock.h>
35 #include <linux/pm.h>
36 #include <linux/pci.h>
37 #include <linux/acpi.h>
38 #ifdef CONFIG_X86_IO_APIC
39 #include <asm/mpspec.h>
40 #endif
41 #ifdef CONFIG_IOSAPIC
42 # include <asm/iosapic.h>
43 #endif
44 #include <acpi/acpi_bus.h>
45 #include <acpi/acpi_drivers.h>
46
47
48 #define _COMPONENT ACPI_PCI_COMPONENT
49 ACPI_MODULE_NAME ("pci_irq")
50
51 #define PREFIX "PCI: "
52
53 struct acpi_prt_list acpi_prt;
54
55 #ifdef CONFIG_X86
56 extern void eisa_set_level_irq(unsigned int irq);
57 #endif
58
59
60 /* --------------------------------------------------------------------------
61 PCI IRQ Routing Table (PRT) Support
62 -------------------------------------------------------------------------- */
63
64 static struct acpi_prt_entry *
acpi_pci_irq_find_prt_entry(int segment,int bus,int device,int pin)65 acpi_pci_irq_find_prt_entry (
66 int segment,
67 int bus,
68 int device,
69 int pin)
70 {
71 struct list_head *node = NULL;
72 struct acpi_prt_entry *entry = NULL;
73
74 ACPI_FUNCTION_TRACE("acpi_pci_irq_find_prt_entry");
75
76 if (!acpi_prt.count)
77 return_PTR(NULL);
78
79 /*
80 * Parse through all PRT entries looking for a match on the specified
81 * PCI device's segment, bus, device, and pin (don't care about func).
82 *
83 * TBD: Acquire/release lock
84 */
85 list_for_each(node, &acpi_prt.entries) {
86 entry = list_entry(node, struct acpi_prt_entry, node);
87 if ((segment == entry->id.segment)
88 && (bus == entry->id.bus)
89 && (device == entry->id.device)
90 && (pin == entry->pin)) {
91 return_PTR(entry);
92 }
93 }
94
95 return_PTR(NULL);
96 }
97
98
99 static int
acpi_pci_irq_add_entry(acpi_handle handle,int segment,int bus,struct acpi_pci_routing_table * prt)100 acpi_pci_irq_add_entry (
101 acpi_handle handle,
102 int segment,
103 int bus,
104 struct acpi_pci_routing_table *prt)
105 {
106 struct acpi_prt_entry *entry = NULL;
107
108 ACPI_FUNCTION_TRACE("acpi_pci_irq_add_entry");
109
110 if (!prt)
111 return_VALUE(-EINVAL);
112
113 entry = kmalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);
114 if (!entry)
115 return_VALUE(-ENOMEM);
116 memset(entry, 0, sizeof(struct acpi_prt_entry));
117
118 entry->id.segment = segment;
119 entry->id.bus = bus;
120 entry->id.device = (prt->address >> 16) & 0xFFFF;
121 entry->id.function = prt->address & 0xFFFF;
122 entry->pin = prt->pin;
123
124 /*
125 * Type 1: Dynamic
126 * ---------------
127 * The 'source' field specifies the PCI interrupt link device used to
128 * configure the IRQ assigned to this slot|dev|pin. The 'source_index'
129 * indicates which resource descriptor in the resource template (of
130 * the link device) this interrupt is allocated from.
131 *
132 * NOTE: Don't query the Link Device for IRQ information at this time
133 * because Link Device enumeration may not have occurred yet
134 * (e.g. exists somewhere 'below' this _PRT entry in the ACPI
135 * namespace).
136 */
137 if (prt->source[0]) {
138 acpi_get_handle(handle, prt->source, &entry->link.handle);
139 entry->link.index = prt->source_index;
140 }
141 /*
142 * Type 2: Static
143 * --------------
144 * The 'source' field is NULL, and the 'source_index' field specifies
145 * the IRQ value, which is hardwired to specific interrupt inputs on
146 * the interrupt controller.
147 */
148 else
149 entry->link.index = prt->source_index;
150
151 ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
152 " %02X:%02X:%02X[%c] -> %s[%d]\n",
153 entry->id.segment, entry->id.bus, entry->id.device,
154 ('A' + entry->pin), prt->source, entry->link.index));
155
156 /* TBD: Acquire/release lock */
157 list_add_tail(&entry->node, &acpi_prt.entries);
158 acpi_prt.count++;
159
160 return_VALUE(0);
161 }
162
163
164 int
acpi_pci_irq_add_prt(acpi_handle handle,int segment,int bus)165 acpi_pci_irq_add_prt (
166 acpi_handle handle,
167 int segment,
168 int bus)
169 {
170 acpi_status status = AE_OK;
171 char pathname[ACPI_PATHNAME_MAX] = {0};
172 struct acpi_buffer buffer = {0, NULL};
173 struct acpi_pci_routing_table *prt = NULL;
174 struct acpi_pci_routing_table *entry = NULL;
175 static int first_time = 1;
176
177 ACPI_FUNCTION_TRACE("acpi_pci_irq_add_prt");
178
179 if (first_time) {
180 acpi_prt.count = 0;
181 INIT_LIST_HEAD(&acpi_prt.entries);
182 first_time = 0;
183 }
184
185 /*
186 * NOTE: We're given a 'handle' to the _PRT object's parent device
187 * (either a PCI root bridge or PCI-PCI bridge).
188 */
189
190 buffer.length = sizeof(pathname);
191 buffer.pointer = pathname;
192 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
193
194 printk(KERN_DEBUG "ACPI: PCI Interrupt Routing Table [%s._PRT]\n",
195 pathname);
196
197 /*
198 * Evaluate this _PRT and add its entries to our global list (acpi_prt).
199 */
200
201 buffer.length = 0;
202 buffer.pointer = NULL;
203 status = acpi_get_irq_routing_table(handle, &buffer);
204 if (status != AE_BUFFER_OVERFLOW) {
205 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRT [%s]\n",
206 acpi_format_exception(status)));
207 return_VALUE(-ENODEV);
208 }
209
210 prt = kmalloc(buffer.length, GFP_KERNEL);
211 if (!prt)
212 return_VALUE(-ENOMEM);
213 memset(prt, 0, buffer.length);
214 buffer.pointer = prt;
215
216 status = acpi_get_irq_routing_table(handle, &buffer);
217 if (ACPI_FAILURE(status)) {
218 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRT [%s]\n",
219 acpi_format_exception(status)));
220 kfree(buffer.pointer);
221 return_VALUE(-ENODEV);
222 }
223
224 entry = prt;
225
226 while (entry && (entry->length > 0)) {
227 acpi_pci_irq_add_entry(handle, segment, bus, entry);
228 entry = (struct acpi_pci_routing_table *)
229 ((unsigned long) entry + entry->length);
230 }
231
232 kfree(prt);
233
234 return_VALUE(0);
235 }
236
237
238 /* --------------------------------------------------------------------------
239 PCI Interrupt Routing Support
240 -------------------------------------------------------------------------- */
241
242 int
acpi_pci_irq_lookup(int segment,int bus,int device,int pin)243 acpi_pci_irq_lookup (
244 int segment,
245 int bus,
246 int device,
247 int pin)
248 {
249 struct acpi_prt_entry *entry = NULL;
250
251 ACPI_FUNCTION_TRACE("acpi_pci_irq_lookup");
252
253 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
254 "Searching for PRT entry for %02x:%02x:%02x[%c]\n",
255 segment, bus, device, ('A' + pin)));
256
257 entry = acpi_pci_irq_find_prt_entry(segment, bus, device, pin);
258 if (!entry) {
259 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PRT entry not found\n"));
260 return_VALUE(0);
261 }
262
263 if (!entry->irq && entry->link.handle) {
264 entry->irq = acpi_pci_link_get_irq(entry->link.handle, entry->link.index, NULL, NULL);
265 if (!entry->irq) {
266 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid IRQ link routing entry\n"));
267 return_VALUE(0);
268 }
269 }
270 else if (!entry->irq) {
271 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Invalid static routing entry (IRQ 0)\n"));
272 return_VALUE(0);
273 }
274
275 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found IRQ %d\n", entry->irq));
276
277 return_VALUE(entry->irq);
278 }
279
280 static int
acpi_pci_irq_derive(struct pci_dev * dev,int pin)281 acpi_pci_irq_derive (
282 struct pci_dev *dev,
283 int pin)
284 {
285 struct pci_dev *bridge = dev;
286 int irq = 0;
287 u8 bridge_pin = 0;
288
289 ACPI_FUNCTION_TRACE("acpi_pci_irq_derive");
290
291 if (!dev)
292 return_VALUE(-EINVAL);
293
294 /*
295 * Attempt to derive an IRQ for this device from a parent bridge's
296 * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge)
297 */
298 while (!irq && bridge->bus->self) {
299 pin = (pin + PCI_SLOT(bridge->devfn)) % 4;
300 bridge = bridge->bus->self;
301
302 if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
303 /* PC card has the same IRQ as its cardbridge */
304 pci_read_config_byte(bridge, PCI_INTERRUPT_PIN, &bridge_pin);
305 if (!bridge_pin) {
306 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
307 "No interrupt pin configured for device %s\n",
308 pci_name(bridge)));
309 return_VALUE(0);
310 }
311 /* Pin is from 0 to 3 */
312 bridge_pin --;
313 pin = bridge_pin;
314 }
315
316 irq = acpi_pci_irq_lookup(0, bridge->bus->number,
317 PCI_SLOT(bridge->devfn), pin);
318 }
319
320 if (!irq) {
321 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Unable to derive IRQ for device %s\n", dev->slot_name));
322 return_VALUE(0);
323 }
324
325 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Derive IRQ %d for device %s from %s\n",
326 irq, pci_name(dev), pci_name(bridge)));
327
328 return_VALUE(irq);
329 }
330
331
332 int
acpi_pci_irq_enable(struct pci_dev * dev)333 acpi_pci_irq_enable (
334 struct pci_dev *dev)
335 {
336 int irq = 0;
337 u8 pin = 0;
338 extern int via_interrupt_line_quirk;
339
340 ACPI_FUNCTION_TRACE("acpi_pci_irq_enable");
341
342 if (!dev)
343 return_VALUE(-EINVAL);
344
345 pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
346 if (!pin) {
347 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No interrupt pin configured for device %s\n", dev->slot_name));
348 return_VALUE(0);
349 }
350 pin--;
351
352 if (!dev->bus) {
353 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid (NULL) 'bus' field\n"));
354 return_VALUE(-ENODEV);
355 }
356
357 /*
358 * First we check the PCI IRQ routing table (PRT) for an IRQ. PRT
359 * values override any BIOS-assigned IRQs set during boot.
360 */
361 irq = acpi_pci_irq_lookup(0, dev->bus->number, PCI_SLOT(dev->devfn), pin);
362
363 /*
364 * If no PRT entry was found, we'll try to derive an IRQ from the
365 * device's parent bridge.
366 */
367 if (!irq)
368 irq = acpi_pci_irq_derive(dev, pin);
369
370 /*
371 * No IRQ known to the ACPI subsystem - maybe the BIOS /
372 * driver reported one, then use it. Exit in any case.
373 */
374 if (!irq) {
375 printk(KERN_WARNING PREFIX "No IRQ known for interrupt pin %c of device %s", ('A' + pin), dev->slot_name);
376 /* Interrupt Line values above 0xF are forbidden */
377 if (dev->irq && (dev->irq <= 0xF)) {
378 printk(" - using IRQ %d\n", dev->irq);
379 return_VALUE(dev->irq);
380 }
381 else {
382 printk("\n");
383 return_VALUE(0);
384 }
385 }
386
387 if (via_interrupt_line_quirk)
388 pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq & 15);
389
390 dev->irq = irq;
391
392 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device %s using IRQ %d\n", dev->slot_name, dev->irq));
393
394 /*
395 * Make sure all (legacy) PCI IRQs are set as level-triggered.
396 */
397 #ifdef CONFIG_X86
398 {
399 static u16 irq_mask;
400 if ((dev->irq < 16) && !((1 << dev->irq) & irq_mask)) {
401 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Setting IRQ %d as level-triggered\n", dev->irq));
402 irq_mask |= (1 << dev->irq);
403 eisa_set_level_irq(dev->irq);
404 }
405 }
406 #endif
407 #ifdef CONFIG_IOSAPIC
408 if (acpi_irq_model == ACPI_IRQ_MODEL_IOSAPIC)
409 iosapic_enable_intr(dev->irq);
410 #endif
411
412 return_VALUE(dev->irq);
413 }
414
415
416 int __init
acpi_pci_irq_init(void)417 acpi_pci_irq_init (void)
418 {
419 struct pci_dev *dev = NULL;
420
421 ACPI_FUNCTION_TRACE("acpi_pci_irq_init");
422
423 if (!acpi_prt.count) {
424 printk(KERN_WARNING PREFIX "ACPI tables contain no PCI IRQ "
425 "routing entries\n");
426 return_VALUE(-ENODEV);
427 }
428
429 /* Make sure all link devices have a valid IRQ. */
430 if (acpi_pci_link_check()) {
431 return_VALUE(-ENODEV);
432 }
433
434 #ifdef CONFIG_X86_IO_APIC
435 /* Program IOAPICs using data from PRT entries. */
436 if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)
437 mp_parse_prt();
438 #endif
439 #ifdef CONFIG_IOSAPIC
440 if (acpi_irq_model == ACPI_IRQ_MODEL_IOSAPIC)
441 iosapic_parse_prt();
442 #endif
443
444 pci_for_each_dev(dev)
445 acpi_pci_irq_enable(dev);
446
447 return_VALUE(0);
448 }
449