Commit | Line | Data |
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85f2bf9f ME |
1 | /* |
2 | * Copyright 2006 Jake Moilanen <moilanen@austin.ibm.com>, IBM Corp. | |
3 | * Copyright 2006-2007 Michael Ellerman, IBM Corp. | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or | |
6 | * modify it under the terms of the GNU General Public License | |
7 | * as published by the Free Software Foundation; version 2 of the | |
8 | * License. | |
9 | * | |
10 | */ | |
11 | ||
12 | #include <linux/device.h> | |
13 | #include <linux/irq.h> | |
14 | #include <linux/msi.h> | |
15 | ||
16 | #include <asm/rtas.h> | |
17 | #include <asm/hw_irq.h> | |
18 | #include <asm/ppc-pci.h> | |
19 | ||
20 | static int query_token, change_token; | |
21 | ||
22 | #define RTAS_QUERY_FN 0 | |
23 | #define RTAS_CHANGE_FN 1 | |
24 | #define RTAS_RESET_FN 2 | |
25 | #define RTAS_CHANGE_MSI_FN 3 | |
26 | #define RTAS_CHANGE_MSIX_FN 4 | |
27 | ||
28 | static struct pci_dn *get_pdn(struct pci_dev *pdev) | |
29 | { | |
30 | struct device_node *dn; | |
31 | struct pci_dn *pdn; | |
32 | ||
33 | dn = pci_device_to_OF_node(pdev); | |
34 | if (!dn) { | |
35 | dev_dbg(&pdev->dev, "rtas_msi: No OF device node\n"); | |
36 | return NULL; | |
37 | } | |
38 | ||
39 | pdn = PCI_DN(dn); | |
40 | if (!pdn) { | |
41 | dev_dbg(&pdev->dev, "rtas_msi: No PCI DN\n"); | |
42 | return NULL; | |
43 | } | |
44 | ||
45 | return pdn; | |
46 | } | |
47 | ||
48 | /* RTAS Helpers */ | |
49 | ||
50 | static int rtas_change_msi(struct pci_dn *pdn, u32 func, u32 num_irqs) | |
51 | { | |
52 | u32 addr, seq_num, rtas_ret[3]; | |
53 | unsigned long buid; | |
54 | int rc; | |
55 | ||
56 | addr = rtas_config_addr(pdn->busno, pdn->devfn, 0); | |
57 | buid = pdn->phb->buid; | |
58 | ||
59 | seq_num = 1; | |
60 | do { | |
61 | if (func == RTAS_CHANGE_MSI_FN || func == RTAS_CHANGE_MSIX_FN) | |
62 | rc = rtas_call(change_token, 6, 4, rtas_ret, addr, | |
63 | BUID_HI(buid), BUID_LO(buid), | |
64 | func, num_irqs, seq_num); | |
65 | else | |
66 | rc = rtas_call(change_token, 6, 3, rtas_ret, addr, | |
67 | BUID_HI(buid), BUID_LO(buid), | |
68 | func, num_irqs, seq_num); | |
69 | ||
70 | seq_num = rtas_ret[1]; | |
71 | } while (rtas_busy_delay(rc)); | |
72 | ||
d385366a | 73 | /* |
6071ed04 ME |
74 | * If the RTAS call succeeded, return the number of irqs allocated. |
75 | * If not, make sure we return a negative error code. | |
d385366a | 76 | */ |
6071ed04 ME |
77 | if (rc == 0) |
78 | rc = rtas_ret[0]; | |
79 | else if (rc > 0) | |
80 | rc = -rc; | |
85f2bf9f | 81 | |
d385366a ME |
82 | pr_debug("rtas_msi: ibm,change_msi(func=%d,num=%d), got %d rc = %d\n", |
83 | func, num_irqs, rtas_ret[0], rc); | |
85f2bf9f ME |
84 | |
85 | return rc; | |
86 | } | |
87 | ||
88 | static void rtas_disable_msi(struct pci_dev *pdev) | |
89 | { | |
90 | struct pci_dn *pdn; | |
91 | ||
92 | pdn = get_pdn(pdev); | |
93 | if (!pdn) | |
94 | return; | |
95 | ||
6071ed04 | 96 | if (rtas_change_msi(pdn, RTAS_CHANGE_FN, 0) != 0) |
85f2bf9f ME |
97 | pr_debug("rtas_msi: Setting MSIs to 0 failed!\n"); |
98 | } | |
99 | ||
100 | static int rtas_query_irq_number(struct pci_dn *pdn, int offset) | |
101 | { | |
102 | u32 addr, rtas_ret[2]; | |
103 | unsigned long buid; | |
104 | int rc; | |
105 | ||
106 | addr = rtas_config_addr(pdn->busno, pdn->devfn, 0); | |
107 | buid = pdn->phb->buid; | |
108 | ||
109 | do { | |
110 | rc = rtas_call(query_token, 4, 3, rtas_ret, addr, | |
111 | BUID_HI(buid), BUID_LO(buid), offset); | |
112 | } while (rtas_busy_delay(rc)); | |
113 | ||
114 | if (rc) { | |
115 | pr_debug("rtas_msi: error (%d) querying source number\n", rc); | |
116 | return rc; | |
117 | } | |
118 | ||
119 | return rtas_ret[0]; | |
120 | } | |
121 | ||
122 | static void rtas_teardown_msi_irqs(struct pci_dev *pdev) | |
123 | { | |
124 | struct msi_desc *entry; | |
125 | ||
126 | list_for_each_entry(entry, &pdev->msi_list, list) { | |
127 | if (entry->irq == NO_IRQ) | |
128 | continue; | |
129 | ||
130 | set_irq_msi(entry->irq, NULL); | |
131 | irq_dispose_mapping(entry->irq); | |
132 | } | |
133 | ||
134 | rtas_disable_msi(pdev); | |
135 | } | |
136 | ||
3a51c0cb | 137 | static int check_req(struct pci_dev *pdev, int nvec, char *prop_name) |
85f2bf9f ME |
138 | { |
139 | struct device_node *dn; | |
140 | struct pci_dn *pdn; | |
141 | const u32 *req_msi; | |
142 | ||
143 | pdn = get_pdn(pdev); | |
144 | if (!pdn) | |
145 | return -ENODEV; | |
146 | ||
147 | dn = pdn->node; | |
148 | ||
3a51c0cb | 149 | req_msi = of_get_property(dn, prop_name, NULL); |
85f2bf9f | 150 | if (!req_msi) { |
3a51c0cb | 151 | pr_debug("rtas_msi: No %s on %s\n", prop_name, dn->full_name); |
85f2bf9f ME |
152 | return -ENOENT; |
153 | } | |
154 | ||
155 | if (*req_msi < nvec) { | |
3a51c0cb | 156 | pr_debug("rtas_msi: %s requests < %d MSIs\n", prop_name, nvec); |
d523cc37 ME |
157 | |
158 | if (*req_msi == 0) /* Be paranoid */ | |
159 | return -ENOSPC; | |
160 | ||
161 | return *req_msi; | |
85f2bf9f ME |
162 | } |
163 | ||
164 | return 0; | |
165 | } | |
166 | ||
3a51c0cb ME |
167 | static int check_req_msi(struct pci_dev *pdev, int nvec) |
168 | { | |
169 | return check_req(pdev, nvec, "ibm,req#msi"); | |
170 | } | |
171 | ||
172 | static int check_req_msix(struct pci_dev *pdev, int nvec) | |
173 | { | |
174 | return check_req(pdev, nvec, "ibm,req#msi-x"); | |
175 | } | |
176 | ||
448e2ca0 ME |
177 | /* Quota calculation */ |
178 | ||
179 | static struct device_node *find_pe_total_msi(struct pci_dev *dev, int *total) | |
180 | { | |
181 | struct device_node *dn; | |
182 | const u32 *p; | |
183 | ||
184 | dn = of_node_get(pci_device_to_OF_node(dev)); | |
185 | while (dn) { | |
186 | p = of_get_property(dn, "ibm,pe-total-#msi", NULL); | |
187 | if (p) { | |
188 | pr_debug("rtas_msi: found prop on dn %s\n", | |
189 | dn->full_name); | |
190 | *total = *p; | |
191 | return dn; | |
192 | } | |
193 | ||
194 | dn = of_get_next_parent(dn); | |
195 | } | |
196 | ||
197 | return NULL; | |
198 | } | |
199 | ||
200 | static struct device_node *find_pe_dn(struct pci_dev *dev, int *total) | |
201 | { | |
202 | struct device_node *dn; | |
203 | ||
204 | /* Found our PE and assume 8 at that point. */ | |
205 | ||
206 | dn = pci_device_to_OF_node(dev); | |
207 | if (!dn) | |
208 | return NULL; | |
209 | ||
210 | dn = find_device_pe(dn); | |
211 | if (!dn) | |
212 | return NULL; | |
213 | ||
214 | /* We actually want the parent */ | |
215 | dn = of_get_parent(dn); | |
216 | if (!dn) | |
217 | return NULL; | |
218 | ||
219 | /* Hardcode of 8 for old firmwares */ | |
220 | *total = 8; | |
221 | pr_debug("rtas_msi: using PE dn %s\n", dn->full_name); | |
222 | ||
223 | return dn; | |
224 | } | |
225 | ||
226 | struct msi_counts { | |
227 | struct device_node *requestor; | |
228 | int num_devices; | |
229 | int request; | |
230 | int quota; | |
231 | int spare; | |
232 | int over_quota; | |
233 | }; | |
234 | ||
235 | static void *count_non_bridge_devices(struct device_node *dn, void *data) | |
236 | { | |
237 | struct msi_counts *counts = data; | |
238 | const u32 *p; | |
239 | u32 class; | |
240 | ||
241 | pr_debug("rtas_msi: counting %s\n", dn->full_name); | |
242 | ||
243 | p = of_get_property(dn, "class-code", NULL); | |
244 | class = p ? *p : 0; | |
245 | ||
246 | if ((class >> 8) != PCI_CLASS_BRIDGE_PCI) | |
247 | counts->num_devices++; | |
248 | ||
249 | return NULL; | |
250 | } | |
251 | ||
252 | static void *count_spare_msis(struct device_node *dn, void *data) | |
253 | { | |
254 | struct msi_counts *counts = data; | |
255 | const u32 *p; | |
256 | int req; | |
257 | ||
258 | if (dn == counts->requestor) | |
259 | req = counts->request; | |
260 | else { | |
261 | /* We don't know if a driver will try to use MSI or MSI-X, | |
262 | * so we just have to punt and use the larger of the two. */ | |
263 | req = 0; | |
264 | p = of_get_property(dn, "ibm,req#msi", NULL); | |
265 | if (p) | |
266 | req = *p; | |
267 | ||
268 | p = of_get_property(dn, "ibm,req#msi-x", NULL); | |
269 | if (p) | |
270 | req = max(req, (int)*p); | |
271 | } | |
272 | ||
273 | if (req < counts->quota) | |
274 | counts->spare += counts->quota - req; | |
275 | else if (req > counts->quota) | |
276 | counts->over_quota++; | |
277 | ||
278 | return NULL; | |
279 | } | |
280 | ||
281 | static int msi_quota_for_device(struct pci_dev *dev, int request) | |
282 | { | |
283 | struct device_node *pe_dn; | |
284 | struct msi_counts counts; | |
285 | int total; | |
286 | ||
287 | pr_debug("rtas_msi: calc quota for %s, request %d\n", pci_name(dev), | |
288 | request); | |
289 | ||
290 | pe_dn = find_pe_total_msi(dev, &total); | |
291 | if (!pe_dn) | |
292 | pe_dn = find_pe_dn(dev, &total); | |
293 | ||
294 | if (!pe_dn) { | |
295 | pr_err("rtas_msi: couldn't find PE for %s\n", pci_name(dev)); | |
296 | goto out; | |
297 | } | |
298 | ||
299 | pr_debug("rtas_msi: found PE %s\n", pe_dn->full_name); | |
300 | ||
301 | memset(&counts, 0, sizeof(struct msi_counts)); | |
302 | ||
303 | /* Work out how many devices we have below this PE */ | |
304 | traverse_pci_devices(pe_dn, count_non_bridge_devices, &counts); | |
305 | ||
306 | if (counts.num_devices == 0) { | |
307 | pr_err("rtas_msi: found 0 devices under PE for %s\n", | |
308 | pci_name(dev)); | |
309 | goto out; | |
310 | } | |
311 | ||
312 | counts.quota = total / counts.num_devices; | |
313 | if (request <= counts.quota) | |
314 | goto out; | |
315 | ||
316 | /* else, we have some more calculating to do */ | |
317 | counts.requestor = pci_device_to_OF_node(dev); | |
318 | counts.request = request; | |
319 | traverse_pci_devices(pe_dn, count_spare_msis, &counts); | |
320 | ||
321 | /* If the quota isn't an integer multiple of the total, we can | |
322 | * use the remainder as spare MSIs for anyone that wants them. */ | |
323 | counts.spare += total % counts.num_devices; | |
324 | ||
325 | /* Divide any spare by the number of over-quota requestors */ | |
326 | if (counts.over_quota) | |
327 | counts.quota += counts.spare / counts.over_quota; | |
328 | ||
329 | /* And finally clamp the request to the possibly adjusted quota */ | |
330 | request = min(counts.quota, request); | |
331 | ||
332 | pr_debug("rtas_msi: request clamped to quota %d\n", request); | |
333 | out: | |
334 | of_node_put(pe_dn); | |
335 | ||
336 | return request; | |
337 | } | |
338 | ||
85f2bf9f ME |
339 | static int rtas_msi_check_device(struct pci_dev *pdev, int nvec, int type) |
340 | { | |
448e2ca0 ME |
341 | int quota, rc; |
342 | ||
85f2bf9f | 343 | if (type == PCI_CAP_ID_MSIX) |
448e2ca0 ME |
344 | rc = check_req_msix(pdev, nvec); |
345 | else | |
346 | rc = check_req_msi(pdev, nvec); | |
347 | ||
348 | if (rc) | |
349 | return rc; | |
85f2bf9f | 350 | |
448e2ca0 ME |
351 | quota = msi_quota_for_device(pdev, nvec); |
352 | ||
353 | if (quota && quota < nvec) | |
354 | return quota; | |
355 | ||
356 | return 0; | |
85f2bf9f ME |
357 | } |
358 | ||
94afa5a5 ME |
359 | static int check_msix_entries(struct pci_dev *pdev) |
360 | { | |
361 | struct msi_desc *entry; | |
362 | int expected; | |
363 | ||
364 | /* There's no way for us to express to firmware that we want | |
365 | * a discontiguous, or non-zero based, range of MSI-X entries. | |
366 | * So we must reject such requests. */ | |
367 | ||
368 | expected = 0; | |
369 | list_for_each_entry(entry, &pdev->msi_list, list) { | |
370 | if (entry->msi_attrib.entry_nr != expected) { | |
371 | pr_debug("rtas_msi: bad MSI-X entries.\n"); | |
372 | return -EINVAL; | |
373 | } | |
374 | expected++; | |
375 | } | |
376 | ||
377 | return 0; | |
378 | } | |
379 | ||
85f2bf9f ME |
380 | static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type) |
381 | { | |
382 | struct pci_dn *pdn; | |
383 | int hwirq, virq, i, rc; | |
384 | struct msi_desc *entry; | |
1db3e890 | 385 | struct msi_msg msg; |
85f2bf9f ME |
386 | |
387 | pdn = get_pdn(pdev); | |
388 | if (!pdn) | |
389 | return -ENODEV; | |
390 | ||
94afa5a5 ME |
391 | if (type == PCI_CAP_ID_MSIX && check_msix_entries(pdev)) |
392 | return -EINVAL; | |
393 | ||
85f2bf9f ME |
394 | /* |
395 | * Try the new more explicit firmware interface, if that fails fall | |
396 | * back to the old interface. The old interface is known to never | |
397 | * return MSI-Xs. | |
398 | */ | |
399 | if (type == PCI_CAP_ID_MSI) { | |
400 | rc = rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, nvec); | |
401 | ||
6071ed04 | 402 | if (rc < 0) { |
85f2bf9f ME |
403 | pr_debug("rtas_msi: trying the old firmware call.\n"); |
404 | rc = rtas_change_msi(pdn, RTAS_CHANGE_FN, nvec); | |
405 | } | |
406 | } else | |
407 | rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, nvec); | |
408 | ||
6071ed04 | 409 | if (rc != nvec) { |
85f2bf9f | 410 | pr_debug("rtas_msi: rtas_change_msi() failed\n"); |
fcbe8090 | 411 | return rc; |
85f2bf9f ME |
412 | } |
413 | ||
414 | i = 0; | |
415 | list_for_each_entry(entry, &pdev->msi_list, list) { | |
e27ed698 | 416 | hwirq = rtas_query_irq_number(pdn, i++); |
85f2bf9f | 417 | if (hwirq < 0) { |
85f2bf9f | 418 | pr_debug("rtas_msi: error (%d) getting hwirq\n", rc); |
fcbe8090 | 419 | return hwirq; |
85f2bf9f ME |
420 | } |
421 | ||
422 | virq = irq_create_mapping(NULL, hwirq); | |
423 | ||
424 | if (virq == NO_IRQ) { | |
425 | pr_debug("rtas_msi: Failed mapping hwirq %d\n", hwirq); | |
fcbe8090 | 426 | return -ENOSPC; |
85f2bf9f ME |
427 | } |
428 | ||
429 | dev_dbg(&pdev->dev, "rtas_msi: allocated virq %d\n", virq); | |
430 | set_irq_msi(virq, entry); | |
1db3e890 ME |
431 | |
432 | /* Read config space back so we can restore after reset */ | |
433 | read_msi_msg(virq, &msg); | |
434 | entry->msg = msg; | |
85f2bf9f ME |
435 | } |
436 | ||
437 | return 0; | |
85f2bf9f ME |
438 | } |
439 | ||
440 | static void rtas_msi_pci_irq_fixup(struct pci_dev *pdev) | |
441 | { | |
442 | /* No LSI -> leave MSIs (if any) configured */ | |
443 | if (pdev->irq == NO_IRQ) { | |
444 | dev_dbg(&pdev->dev, "rtas_msi: no LSI, nothing to do.\n"); | |
445 | return; | |
446 | } | |
447 | ||
448 | /* No MSI -> MSIs can't have been assigned by fw, leave LSI */ | |
649781f8 ME |
449 | if (check_req_msi(pdev, 1) && check_req_msix(pdev, 1)) { |
450 | dev_dbg(&pdev->dev, "rtas_msi: no req#msi/x, nothing to do.\n"); | |
85f2bf9f ME |
451 | return; |
452 | } | |
453 | ||
454 | dev_dbg(&pdev->dev, "rtas_msi: disabling existing MSI.\n"); | |
455 | rtas_disable_msi(pdev); | |
456 | } | |
457 | ||
458 | static int rtas_msi_init(void) | |
459 | { | |
460 | query_token = rtas_token("ibm,query-interrupt-source-number"); | |
461 | change_token = rtas_token("ibm,change-msi"); | |
462 | ||
463 | if ((query_token == RTAS_UNKNOWN_SERVICE) || | |
464 | (change_token == RTAS_UNKNOWN_SERVICE)) { | |
465 | pr_debug("rtas_msi: no RTAS tokens, no MSI support.\n"); | |
466 | return -1; | |
467 | } | |
468 | ||
469 | pr_debug("rtas_msi: Registering RTAS MSI callbacks.\n"); | |
470 | ||
471 | WARN_ON(ppc_md.setup_msi_irqs); | |
472 | ppc_md.setup_msi_irqs = rtas_setup_msi_irqs; | |
473 | ppc_md.teardown_msi_irqs = rtas_teardown_msi_irqs; | |
474 | ppc_md.msi_check_device = rtas_msi_check_device; | |
475 | ||
476 | WARN_ON(ppc_md.pci_irq_fixup); | |
477 | ppc_md.pci_irq_fixup = rtas_msi_pci_irq_fixup; | |
478 | ||
479 | return 0; | |
480 | } | |
481 | arch_initcall(rtas_msi_init); |