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> | |
8e83e905 | 19 | #include <asm/machdep.h> |
85f2bf9f ME |
20 | |
21 | static int query_token, change_token; | |
22 | ||
23 | #define RTAS_QUERY_FN 0 | |
24 | #define RTAS_CHANGE_FN 1 | |
25 | #define RTAS_RESET_FN 2 | |
26 | #define RTAS_CHANGE_MSI_FN 3 | |
27 | #define RTAS_CHANGE_MSIX_FN 4 | |
e61133dd | 28 | #define RTAS_CHANGE_32MSI_FN 5 |
85f2bf9f | 29 | |
85f2bf9f ME |
30 | /* RTAS Helpers */ |
31 | ||
32 | static int rtas_change_msi(struct pci_dn *pdn, u32 func, u32 num_irqs) | |
33 | { | |
34 | u32 addr, seq_num, rtas_ret[3]; | |
35 | unsigned long buid; | |
36 | int rc; | |
37 | ||
38 | addr = rtas_config_addr(pdn->busno, pdn->devfn, 0); | |
39 | buid = pdn->phb->buid; | |
40 | ||
41 | seq_num = 1; | |
42 | do { | |
e61133dd BK |
43 | if (func == RTAS_CHANGE_MSI_FN || func == RTAS_CHANGE_MSIX_FN || |
44 | func == RTAS_CHANGE_32MSI_FN) | |
85f2bf9f ME |
45 | rc = rtas_call(change_token, 6, 4, rtas_ret, addr, |
46 | BUID_HI(buid), BUID_LO(buid), | |
47 | func, num_irqs, seq_num); | |
48 | else | |
49 | rc = rtas_call(change_token, 6, 3, rtas_ret, addr, | |
50 | BUID_HI(buid), BUID_LO(buid), | |
51 | func, num_irqs, seq_num); | |
52 | ||
53 | seq_num = rtas_ret[1]; | |
54 | } while (rtas_busy_delay(rc)); | |
55 | ||
d385366a | 56 | /* |
6071ed04 ME |
57 | * If the RTAS call succeeded, return the number of irqs allocated. |
58 | * If not, make sure we return a negative error code. | |
d385366a | 59 | */ |
6071ed04 ME |
60 | if (rc == 0) |
61 | rc = rtas_ret[0]; | |
62 | else if (rc > 0) | |
63 | rc = -rc; | |
85f2bf9f | 64 | |
d385366a ME |
65 | pr_debug("rtas_msi: ibm,change_msi(func=%d,num=%d), got %d rc = %d\n", |
66 | func, num_irqs, rtas_ret[0], rc); | |
85f2bf9f ME |
67 | |
68 | return rc; | |
69 | } | |
70 | ||
71 | static void rtas_disable_msi(struct pci_dev *pdev) | |
72 | { | |
73 | struct pci_dn *pdn; | |
74 | ||
b72c1f65 | 75 | pdn = pci_get_pdn(pdev); |
85f2bf9f ME |
76 | if (!pdn) |
77 | return; | |
78 | ||
964a2996 NA |
79 | /* |
80 | * disabling MSI with the explicit interface also disables MSI-X | |
81 | */ | |
82 | if (rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, 0) != 0) { | |
83 | /* | |
84 | * may have failed because explicit interface is not | |
85 | * present | |
86 | */ | |
87 | if (rtas_change_msi(pdn, RTAS_CHANGE_FN, 0) != 0) { | |
88 | pr_debug("rtas_msi: Setting MSIs to 0 failed!\n"); | |
89 | } | |
90 | } | |
85f2bf9f ME |
91 | } |
92 | ||
93 | static int rtas_query_irq_number(struct pci_dn *pdn, int offset) | |
94 | { | |
95 | u32 addr, rtas_ret[2]; | |
96 | unsigned long buid; | |
97 | int rc; | |
98 | ||
99 | addr = rtas_config_addr(pdn->busno, pdn->devfn, 0); | |
100 | buid = pdn->phb->buid; | |
101 | ||
102 | do { | |
103 | rc = rtas_call(query_token, 4, 3, rtas_ret, addr, | |
104 | BUID_HI(buid), BUID_LO(buid), offset); | |
105 | } while (rtas_busy_delay(rc)); | |
106 | ||
107 | if (rc) { | |
108 | pr_debug("rtas_msi: error (%d) querying source number\n", rc); | |
109 | return rc; | |
110 | } | |
111 | ||
112 | return rtas_ret[0]; | |
113 | } | |
114 | ||
115 | static void rtas_teardown_msi_irqs(struct pci_dev *pdev) | |
116 | { | |
117 | struct msi_desc *entry; | |
118 | ||
119 | list_for_each_entry(entry, &pdev->msi_list, list) { | |
120 | if (entry->irq == NO_IRQ) | |
121 | continue; | |
122 | ||
ec775d0e | 123 | irq_set_msi_desc(entry->irq, NULL); |
85f2bf9f ME |
124 | irq_dispose_mapping(entry->irq); |
125 | } | |
126 | ||
127 | rtas_disable_msi(pdev); | |
128 | } | |
129 | ||
3a51c0cb | 130 | static int check_req(struct pci_dev *pdev, int nvec, char *prop_name) |
85f2bf9f ME |
131 | { |
132 | struct device_node *dn; | |
133 | struct pci_dn *pdn; | |
8d153155 AB |
134 | const __be32 *p; |
135 | u32 req_msi; | |
85f2bf9f | 136 | |
b72c1f65 | 137 | pdn = pci_get_pdn(pdev); |
85f2bf9f ME |
138 | if (!pdn) |
139 | return -ENODEV; | |
140 | ||
141 | dn = pdn->node; | |
142 | ||
8d153155 AB |
143 | p = of_get_property(dn, prop_name, NULL); |
144 | if (!p) { | |
3a51c0cb | 145 | pr_debug("rtas_msi: No %s on %s\n", prop_name, dn->full_name); |
85f2bf9f ME |
146 | return -ENOENT; |
147 | } | |
148 | ||
8d153155 AB |
149 | req_msi = be32_to_cpup(p); |
150 | if (req_msi < nvec) { | |
3a51c0cb | 151 | pr_debug("rtas_msi: %s requests < %d MSIs\n", prop_name, nvec); |
d523cc37 | 152 | |
8d153155 | 153 | if (req_msi == 0) /* Be paranoid */ |
d523cc37 ME |
154 | return -ENOSPC; |
155 | ||
8d153155 | 156 | return req_msi; |
85f2bf9f ME |
157 | } |
158 | ||
159 | return 0; | |
160 | } | |
161 | ||
3a51c0cb ME |
162 | static int check_req_msi(struct pci_dev *pdev, int nvec) |
163 | { | |
164 | return check_req(pdev, nvec, "ibm,req#msi"); | |
165 | } | |
166 | ||
167 | static int check_req_msix(struct pci_dev *pdev, int nvec) | |
168 | { | |
169 | return check_req(pdev, nvec, "ibm,req#msi-x"); | |
170 | } | |
171 | ||
448e2ca0 ME |
172 | /* Quota calculation */ |
173 | ||
174 | static struct device_node *find_pe_total_msi(struct pci_dev *dev, int *total) | |
175 | { | |
176 | struct device_node *dn; | |
8d153155 | 177 | const __be32 *p; |
448e2ca0 ME |
178 | |
179 | dn = of_node_get(pci_device_to_OF_node(dev)); | |
180 | while (dn) { | |
181 | p = of_get_property(dn, "ibm,pe-total-#msi", NULL); | |
182 | if (p) { | |
183 | pr_debug("rtas_msi: found prop on dn %s\n", | |
184 | dn->full_name); | |
8d153155 | 185 | *total = be32_to_cpup(p); |
448e2ca0 ME |
186 | return dn; |
187 | } | |
188 | ||
189 | dn = of_get_next_parent(dn); | |
190 | } | |
191 | ||
192 | return NULL; | |
193 | } | |
194 | ||
195 | static struct device_node *find_pe_dn(struct pci_dev *dev, int *total) | |
196 | { | |
197 | struct device_node *dn; | |
66523d9f | 198 | struct eeh_dev *edev; |
448e2ca0 ME |
199 | |
200 | /* Found our PE and assume 8 at that point. */ | |
201 | ||
202 | dn = pci_device_to_OF_node(dev); | |
203 | if (!dn) | |
204 | return NULL; | |
205 | ||
66523d9f GS |
206 | /* Get the top level device in the PE */ |
207 | edev = of_node_to_eeh_dev(dn); | |
bb461882 AK |
208 | if (edev->pe) |
209 | edev = list_first_entry(&edev->pe->edevs, struct eeh_dev, list); | |
66523d9f | 210 | dn = eeh_dev_to_of_node(edev); |
448e2ca0 ME |
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; | |
8d153155 | 238 | const __be32 *p; |
448e2ca0 ME |
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); | |
8d153155 | 244 | class = p ? be32_to_cpup(p) : 0; |
448e2ca0 ME |
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; | |
8d153155 | 255 | const __be32 *p; |
448e2ca0 ME |
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) | |
8d153155 | 266 | req = be32_to_cpup(p); |
448e2ca0 ME |
267 | |
268 | p = of_get_property(dn, "ibm,req#msi-x", NULL); | |
269 | if (p) | |
8d153155 | 270 | req = max(req, (int)be32_to_cpup(p)); |
448e2ca0 ME |
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 | ||
94afa5a5 ME |
339 | static int check_msix_entries(struct pci_dev *pdev) |
340 | { | |
341 | struct msi_desc *entry; | |
342 | int expected; | |
343 | ||
344 | /* There's no way for us to express to firmware that we want | |
345 | * a discontiguous, or non-zero based, range of MSI-X entries. | |
346 | * So we must reject such requests. */ | |
347 | ||
348 | expected = 0; | |
349 | list_for_each_entry(entry, &pdev->msi_list, list) { | |
350 | if (entry->msi_attrib.entry_nr != expected) { | |
351 | pr_debug("rtas_msi: bad MSI-X entries.\n"); | |
352 | return -EINVAL; | |
353 | } | |
354 | expected++; | |
355 | } | |
356 | ||
357 | return 0; | |
358 | } | |
359 | ||
f1dd1531 BK |
360 | static void rtas_hack_32bit_msi_gen2(struct pci_dev *pdev) |
361 | { | |
362 | u32 addr_hi, addr_lo; | |
363 | ||
364 | /* | |
365 | * We should only get in here for IODA1 configs. This is based on the | |
366 | * fact that we using RTAS for MSIs, we don't have the 32 bit MSI RTAS | |
367 | * support, and we are in a PCIe Gen2 slot. | |
368 | */ | |
369 | dev_info(&pdev->dev, | |
370 | "rtas_msi: No 32 bit MSI firmware support, forcing 32 bit MSI\n"); | |
371 | pci_read_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, &addr_hi); | |
372 | addr_lo = 0xffff0000 | ((addr_hi >> (48 - 32)) << 4); | |
373 | pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_LO, addr_lo); | |
374 | pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, 0); | |
375 | } | |
376 | ||
752f5216 | 377 | static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec_in, int type) |
85f2bf9f ME |
378 | { |
379 | struct pci_dn *pdn; | |
6b2fd7ef | 380 | int hwirq, virq, i, quota, rc; |
85f2bf9f | 381 | struct msi_desc *entry; |
1db3e890 | 382 | struct msi_msg msg; |
752f5216 | 383 | int nvec = nvec_in; |
f1dd1531 | 384 | int use_32bit_msi_hack = 0; |
85f2bf9f | 385 | |
6b2fd7ef AG |
386 | if (type == PCI_CAP_ID_MSIX) |
387 | rc = check_req_msix(pdev, nvec); | |
388 | else | |
389 | rc = check_req_msi(pdev, nvec); | |
390 | ||
391 | if (rc) | |
392 | return rc; | |
393 | ||
394 | quota = msi_quota_for_device(pdev, nvec); | |
395 | ||
396 | if (quota && quota < nvec) | |
397 | return quota; | |
85f2bf9f | 398 | |
94afa5a5 ME |
399 | if (type == PCI_CAP_ID_MSIX && check_msix_entries(pdev)) |
400 | return -EINVAL; | |
401 | ||
752f5216 AB |
402 | /* |
403 | * Firmware currently refuse any non power of two allocation | |
404 | * so we round up if the quota will allow it. | |
405 | */ | |
406 | if (type == PCI_CAP_ID_MSIX) { | |
407 | int m = roundup_pow_of_two(nvec); | |
6b2fd7ef | 408 | quota = msi_quota_for_device(pdev, m); |
752f5216 AB |
409 | |
410 | if (quota >= m) | |
411 | nvec = m; | |
412 | } | |
413 | ||
6b2fd7ef AG |
414 | pdn = pci_get_pdn(pdev); |
415 | ||
85f2bf9f ME |
416 | /* |
417 | * Try the new more explicit firmware interface, if that fails fall | |
418 | * back to the old interface. The old interface is known to never | |
419 | * return MSI-Xs. | |
420 | */ | |
752f5216 | 421 | again: |
85f2bf9f | 422 | if (type == PCI_CAP_ID_MSI) { |
f1dd1531 | 423 | if (pdn->force_32bit_msi) { |
e61133dd | 424 | rc = rtas_change_msi(pdn, RTAS_CHANGE_32MSI_FN, nvec); |
f1dd1531 BK |
425 | if (rc < 0) { |
426 | /* | |
427 | * We only want to run the 32 bit MSI hack below if | |
428 | * the max bus speed is Gen2 speed | |
429 | */ | |
430 | if (pdev->bus->max_bus_speed != PCIE_SPEED_5_0GT) | |
431 | return rc; | |
432 | ||
433 | use_32bit_msi_hack = 1; | |
434 | } | |
435 | } else | |
436 | rc = -1; | |
437 | ||
438 | if (rc < 0) | |
e61133dd | 439 | rc = rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, nvec); |
85f2bf9f | 440 | |
f1dd1531 | 441 | if (rc < 0) { |
85f2bf9f ME |
442 | pr_debug("rtas_msi: trying the old firmware call.\n"); |
443 | rc = rtas_change_msi(pdn, RTAS_CHANGE_FN, nvec); | |
444 | } | |
f1dd1531 BK |
445 | |
446 | if (use_32bit_msi_hack && rc > 0) | |
447 | rtas_hack_32bit_msi_gen2(pdev); | |
85f2bf9f ME |
448 | } else |
449 | rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, nvec); | |
450 | ||
6071ed04 | 451 | if (rc != nvec) { |
752f5216 AB |
452 | if (nvec != nvec_in) { |
453 | nvec = nvec_in; | |
454 | goto again; | |
455 | } | |
85f2bf9f | 456 | pr_debug("rtas_msi: rtas_change_msi() failed\n"); |
fcbe8090 | 457 | return rc; |
85f2bf9f ME |
458 | } |
459 | ||
460 | i = 0; | |
461 | list_for_each_entry(entry, &pdev->msi_list, list) { | |
e27ed698 | 462 | hwirq = rtas_query_irq_number(pdn, i++); |
85f2bf9f | 463 | if (hwirq < 0) { |
85f2bf9f | 464 | pr_debug("rtas_msi: error (%d) getting hwirq\n", rc); |
fcbe8090 | 465 | return hwirq; |
85f2bf9f ME |
466 | } |
467 | ||
468 | virq = irq_create_mapping(NULL, hwirq); | |
469 | ||
470 | if (virq == NO_IRQ) { | |
471 | pr_debug("rtas_msi: Failed mapping hwirq %d\n", hwirq); | |
fcbe8090 | 472 | return -ENOSPC; |
85f2bf9f ME |
473 | } |
474 | ||
475 | dev_dbg(&pdev->dev, "rtas_msi: allocated virq %d\n", virq); | |
ec775d0e | 476 | irq_set_msi_desc(virq, entry); |
1db3e890 ME |
477 | |
478 | /* Read config space back so we can restore after reset */ | |
891d4a48 | 479 | __pci_read_msi_msg(entry, &msg); |
1db3e890 | 480 | entry->msg = msg; |
85f2bf9f ME |
481 | } |
482 | ||
483 | return 0; | |
85f2bf9f ME |
484 | } |
485 | ||
486 | static void rtas_msi_pci_irq_fixup(struct pci_dev *pdev) | |
487 | { | |
488 | /* No LSI -> leave MSIs (if any) configured */ | |
489 | if (pdev->irq == NO_IRQ) { | |
490 | dev_dbg(&pdev->dev, "rtas_msi: no LSI, nothing to do.\n"); | |
491 | return; | |
492 | } | |
493 | ||
494 | /* No MSI -> MSIs can't have been assigned by fw, leave LSI */ | |
649781f8 ME |
495 | if (check_req_msi(pdev, 1) && check_req_msix(pdev, 1)) { |
496 | dev_dbg(&pdev->dev, "rtas_msi: no req#msi/x, nothing to do.\n"); | |
85f2bf9f ME |
497 | return; |
498 | } | |
499 | ||
500 | dev_dbg(&pdev->dev, "rtas_msi: disabling existing MSI.\n"); | |
501 | rtas_disable_msi(pdev); | |
502 | } | |
503 | ||
504 | static int rtas_msi_init(void) | |
505 | { | |
506 | query_token = rtas_token("ibm,query-interrupt-source-number"); | |
507 | change_token = rtas_token("ibm,change-msi"); | |
508 | ||
509 | if ((query_token == RTAS_UNKNOWN_SERVICE) || | |
510 | (change_token == RTAS_UNKNOWN_SERVICE)) { | |
511 | pr_debug("rtas_msi: no RTAS tokens, no MSI support.\n"); | |
512 | return -1; | |
513 | } | |
514 | ||
515 | pr_debug("rtas_msi: Registering RTAS MSI callbacks.\n"); | |
516 | ||
517 | WARN_ON(ppc_md.setup_msi_irqs); | |
518 | ppc_md.setup_msi_irqs = rtas_setup_msi_irqs; | |
519 | ppc_md.teardown_msi_irqs = rtas_teardown_msi_irqs; | |
85f2bf9f ME |
520 | |
521 | WARN_ON(ppc_md.pci_irq_fixup); | |
522 | ppc_md.pci_irq_fixup = rtas_msi_pci_irq_fixup; | |
523 | ||
524 | return 0; | |
525 | } | |
8e83e905 | 526 | machine_arch_initcall(pseries, rtas_msi_init); |