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b886d83c | 1 | // SPDX-License-Identifier: GPL-2.0-only |
85f2bf9f ME |
2 | /* |
3 | * Copyright 2006 Jake Moilanen <moilanen@austin.ibm.com>, IBM Corp. | |
4 | * Copyright 2006-2007 Michael Ellerman, IBM Corp. | |
85f2bf9f ME |
5 | */ |
6 | ||
7 | #include <linux/device.h> | |
8 | #include <linux/irq.h> | |
9 | #include <linux/msi.h> | |
10 | ||
11 | #include <asm/rtas.h> | |
12 | #include <asm/hw_irq.h> | |
13 | #include <asm/ppc-pci.h> | |
8e83e905 | 14 | #include <asm/machdep.h> |
85f2bf9f | 15 | |
1d14b875 DA |
16 | #include "pseries.h" |
17 | ||
85f2bf9f ME |
18 | static int query_token, change_token; |
19 | ||
20 | #define RTAS_QUERY_FN 0 | |
21 | #define RTAS_CHANGE_FN 1 | |
22 | #define RTAS_RESET_FN 2 | |
23 | #define RTAS_CHANGE_MSI_FN 3 | |
24 | #define RTAS_CHANGE_MSIX_FN 4 | |
e61133dd | 25 | #define RTAS_CHANGE_32MSI_FN 5 |
85f2bf9f | 26 | |
85f2bf9f ME |
27 | /* RTAS Helpers */ |
28 | ||
29 | static int rtas_change_msi(struct pci_dn *pdn, u32 func, u32 num_irqs) | |
30 | { | |
31 | u32 addr, seq_num, rtas_ret[3]; | |
32 | unsigned long buid; | |
33 | int rc; | |
34 | ||
35 | addr = rtas_config_addr(pdn->busno, pdn->devfn, 0); | |
36 | buid = pdn->phb->buid; | |
37 | ||
38 | seq_num = 1; | |
39 | do { | |
e61133dd BK |
40 | if (func == RTAS_CHANGE_MSI_FN || func == RTAS_CHANGE_MSIX_FN || |
41 | func == RTAS_CHANGE_32MSI_FN) | |
85f2bf9f ME |
42 | rc = rtas_call(change_token, 6, 4, rtas_ret, addr, |
43 | BUID_HI(buid), BUID_LO(buid), | |
44 | func, num_irqs, seq_num); | |
45 | else | |
46 | rc = rtas_call(change_token, 6, 3, rtas_ret, addr, | |
47 | BUID_HI(buid), BUID_LO(buid), | |
48 | func, num_irqs, seq_num); | |
49 | ||
50 | seq_num = rtas_ret[1]; | |
51 | } while (rtas_busy_delay(rc)); | |
52 | ||
d385366a | 53 | /* |
6071ed04 ME |
54 | * If the RTAS call succeeded, return the number of irqs allocated. |
55 | * If not, make sure we return a negative error code. | |
d385366a | 56 | */ |
6071ed04 ME |
57 | if (rc == 0) |
58 | rc = rtas_ret[0]; | |
59 | else if (rc > 0) | |
60 | rc = -rc; | |
85f2bf9f | 61 | |
d385366a ME |
62 | pr_debug("rtas_msi: ibm,change_msi(func=%d,num=%d), got %d rc = %d\n", |
63 | func, num_irqs, rtas_ret[0], rc); | |
85f2bf9f ME |
64 | |
65 | return rc; | |
66 | } | |
67 | ||
68 | static void rtas_disable_msi(struct pci_dev *pdev) | |
69 | { | |
70 | struct pci_dn *pdn; | |
71 | ||
b72c1f65 | 72 | pdn = pci_get_pdn(pdev); |
85f2bf9f ME |
73 | if (!pdn) |
74 | return; | |
75 | ||
964a2996 NA |
76 | /* |
77 | * disabling MSI with the explicit interface also disables MSI-X | |
78 | */ | |
79 | if (rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, 0) != 0) { | |
80 | /* | |
81 | * may have failed because explicit interface is not | |
82 | * present | |
83 | */ | |
84 | if (rtas_change_msi(pdn, RTAS_CHANGE_FN, 0) != 0) { | |
85 | pr_debug("rtas_msi: Setting MSIs to 0 failed!\n"); | |
86 | } | |
87 | } | |
85f2bf9f ME |
88 | } |
89 | ||
90 | static int rtas_query_irq_number(struct pci_dn *pdn, int offset) | |
91 | { | |
92 | u32 addr, rtas_ret[2]; | |
93 | unsigned long buid; | |
94 | int rc; | |
95 | ||
96 | addr = rtas_config_addr(pdn->busno, pdn->devfn, 0); | |
97 | buid = pdn->phb->buid; | |
98 | ||
99 | do { | |
100 | rc = rtas_call(query_token, 4, 3, rtas_ret, addr, | |
101 | BUID_HI(buid), BUID_LO(buid), offset); | |
102 | } while (rtas_busy_delay(rc)); | |
103 | ||
104 | if (rc) { | |
105 | pr_debug("rtas_msi: error (%d) querying source number\n", rc); | |
106 | return rc; | |
107 | } | |
108 | ||
109 | return rtas_ret[0]; | |
110 | } | |
111 | ||
112 | static void rtas_teardown_msi_irqs(struct pci_dev *pdev) | |
113 | { | |
114 | struct msi_desc *entry; | |
115 | ||
2921d179 | 116 | for_each_pci_msi_entry(entry, pdev) { |
ef24ba70 | 117 | if (!entry->irq) |
85f2bf9f ME |
118 | continue; |
119 | ||
ec775d0e | 120 | irq_set_msi_desc(entry->irq, NULL); |
85f2bf9f ME |
121 | irq_dispose_mapping(entry->irq); |
122 | } | |
123 | ||
124 | rtas_disable_msi(pdev); | |
125 | } | |
126 | ||
3a51c0cb | 127 | static int check_req(struct pci_dev *pdev, int nvec, char *prop_name) |
85f2bf9f ME |
128 | { |
129 | struct device_node *dn; | |
8d153155 AB |
130 | const __be32 *p; |
131 | u32 req_msi; | |
85f2bf9f | 132 | |
f1e08232 | 133 | dn = pci_device_to_OF_node(pdev); |
85f2bf9f | 134 | |
8d153155 AB |
135 | p = of_get_property(dn, prop_name, NULL); |
136 | if (!p) { | |
b7c670d6 | 137 | pr_debug("rtas_msi: No %s on %pOF\n", prop_name, dn); |
85f2bf9f ME |
138 | return -ENOENT; |
139 | } | |
140 | ||
8d153155 AB |
141 | req_msi = be32_to_cpup(p); |
142 | if (req_msi < nvec) { | |
3a51c0cb | 143 | pr_debug("rtas_msi: %s requests < %d MSIs\n", prop_name, nvec); |
d523cc37 | 144 | |
8d153155 | 145 | if (req_msi == 0) /* Be paranoid */ |
d523cc37 ME |
146 | return -ENOSPC; |
147 | ||
8d153155 | 148 | return req_msi; |
85f2bf9f ME |
149 | } |
150 | ||
151 | return 0; | |
152 | } | |
153 | ||
3a51c0cb ME |
154 | static int check_req_msi(struct pci_dev *pdev, int nvec) |
155 | { | |
156 | return check_req(pdev, nvec, "ibm,req#msi"); | |
157 | } | |
158 | ||
159 | static int check_req_msix(struct pci_dev *pdev, int nvec) | |
160 | { | |
161 | return check_req(pdev, nvec, "ibm,req#msi-x"); | |
162 | } | |
163 | ||
448e2ca0 ME |
164 | /* Quota calculation */ |
165 | ||
166 | static struct device_node *find_pe_total_msi(struct pci_dev *dev, int *total) | |
167 | { | |
168 | struct device_node *dn; | |
8d153155 | 169 | const __be32 *p; |
448e2ca0 ME |
170 | |
171 | dn = of_node_get(pci_device_to_OF_node(dev)); | |
172 | while (dn) { | |
173 | p = of_get_property(dn, "ibm,pe-total-#msi", NULL); | |
174 | if (p) { | |
b7c670d6 RH |
175 | pr_debug("rtas_msi: found prop on dn %pOF\n", |
176 | dn); | |
8d153155 | 177 | *total = be32_to_cpup(p); |
448e2ca0 ME |
178 | return dn; |
179 | } | |
180 | ||
181 | dn = of_get_next_parent(dn); | |
182 | } | |
183 | ||
184 | return NULL; | |
185 | } | |
186 | ||
187 | static struct device_node *find_pe_dn(struct pci_dev *dev, int *total) | |
188 | { | |
189 | struct device_node *dn; | |
66523d9f | 190 | struct eeh_dev *edev; |
448e2ca0 ME |
191 | |
192 | /* Found our PE and assume 8 at that point. */ | |
193 | ||
194 | dn = pci_device_to_OF_node(dev); | |
195 | if (!dn) | |
196 | return NULL; | |
197 | ||
66523d9f | 198 | /* Get the top level device in the PE */ |
c6406d8f | 199 | edev = pdn_to_eeh_dev(PCI_DN(dn)); |
bb461882 | 200 | if (edev->pe) |
80e65b00 SB |
201 | edev = list_first_entry(&edev->pe->edevs, struct eeh_dev, |
202 | entry); | |
f1e08232 | 203 | dn = pci_device_to_OF_node(edev->pdev); |
448e2ca0 ME |
204 | if (!dn) |
205 | return NULL; | |
206 | ||
207 | /* We actually want the parent */ | |
208 | dn = of_get_parent(dn); | |
209 | if (!dn) | |
210 | return NULL; | |
211 | ||
212 | /* Hardcode of 8 for old firmwares */ | |
213 | *total = 8; | |
b7c670d6 | 214 | pr_debug("rtas_msi: using PE dn %pOF\n", dn); |
448e2ca0 ME |
215 | |
216 | return dn; | |
217 | } | |
218 | ||
219 | struct msi_counts { | |
220 | struct device_node *requestor; | |
221 | int num_devices; | |
222 | int request; | |
223 | int quota; | |
224 | int spare; | |
225 | int over_quota; | |
226 | }; | |
227 | ||
228 | static void *count_non_bridge_devices(struct device_node *dn, void *data) | |
229 | { | |
230 | struct msi_counts *counts = data; | |
8d153155 | 231 | const __be32 *p; |
448e2ca0 ME |
232 | u32 class; |
233 | ||
b7c670d6 | 234 | pr_debug("rtas_msi: counting %pOF\n", dn); |
448e2ca0 ME |
235 | |
236 | p = of_get_property(dn, "class-code", NULL); | |
8d153155 | 237 | class = p ? be32_to_cpup(p) : 0; |
448e2ca0 ME |
238 | |
239 | if ((class >> 8) != PCI_CLASS_BRIDGE_PCI) | |
240 | counts->num_devices++; | |
241 | ||
242 | return NULL; | |
243 | } | |
244 | ||
245 | static void *count_spare_msis(struct device_node *dn, void *data) | |
246 | { | |
247 | struct msi_counts *counts = data; | |
8d153155 | 248 | const __be32 *p; |
448e2ca0 ME |
249 | int req; |
250 | ||
251 | if (dn == counts->requestor) | |
252 | req = counts->request; | |
253 | else { | |
254 | /* We don't know if a driver will try to use MSI or MSI-X, | |
255 | * so we just have to punt and use the larger of the two. */ | |
256 | req = 0; | |
257 | p = of_get_property(dn, "ibm,req#msi", NULL); | |
258 | if (p) | |
8d153155 | 259 | req = be32_to_cpup(p); |
448e2ca0 ME |
260 | |
261 | p = of_get_property(dn, "ibm,req#msi-x", NULL); | |
262 | if (p) | |
8d153155 | 263 | req = max(req, (int)be32_to_cpup(p)); |
448e2ca0 ME |
264 | } |
265 | ||
266 | if (req < counts->quota) | |
267 | counts->spare += counts->quota - req; | |
268 | else if (req > counts->quota) | |
269 | counts->over_quota++; | |
270 | ||
271 | return NULL; | |
272 | } | |
273 | ||
274 | static int msi_quota_for_device(struct pci_dev *dev, int request) | |
275 | { | |
276 | struct device_node *pe_dn; | |
277 | struct msi_counts counts; | |
278 | int total; | |
279 | ||
280 | pr_debug("rtas_msi: calc quota for %s, request %d\n", pci_name(dev), | |
281 | request); | |
282 | ||
283 | pe_dn = find_pe_total_msi(dev, &total); | |
284 | if (!pe_dn) | |
285 | pe_dn = find_pe_dn(dev, &total); | |
286 | ||
287 | if (!pe_dn) { | |
288 | pr_err("rtas_msi: couldn't find PE for %s\n", pci_name(dev)); | |
289 | goto out; | |
290 | } | |
291 | ||
b7c670d6 | 292 | pr_debug("rtas_msi: found PE %pOF\n", pe_dn); |
448e2ca0 ME |
293 | |
294 | memset(&counts, 0, sizeof(struct msi_counts)); | |
295 | ||
296 | /* Work out how many devices we have below this PE */ | |
cdddc577 | 297 | pci_traverse_device_nodes(pe_dn, count_non_bridge_devices, &counts); |
448e2ca0 ME |
298 | |
299 | if (counts.num_devices == 0) { | |
300 | pr_err("rtas_msi: found 0 devices under PE for %s\n", | |
301 | pci_name(dev)); | |
302 | goto out; | |
303 | } | |
304 | ||
305 | counts.quota = total / counts.num_devices; | |
306 | if (request <= counts.quota) | |
307 | goto out; | |
308 | ||
309 | /* else, we have some more calculating to do */ | |
310 | counts.requestor = pci_device_to_OF_node(dev); | |
311 | counts.request = request; | |
cdddc577 | 312 | pci_traverse_device_nodes(pe_dn, count_spare_msis, &counts); |
448e2ca0 ME |
313 | |
314 | /* If the quota isn't an integer multiple of the total, we can | |
315 | * use the remainder as spare MSIs for anyone that wants them. */ | |
316 | counts.spare += total % counts.num_devices; | |
317 | ||
318 | /* Divide any spare by the number of over-quota requestors */ | |
319 | if (counts.over_quota) | |
320 | counts.quota += counts.spare / counts.over_quota; | |
321 | ||
322 | /* And finally clamp the request to the possibly adjusted quota */ | |
323 | request = min(counts.quota, request); | |
324 | ||
325 | pr_debug("rtas_msi: request clamped to quota %d\n", request); | |
326 | out: | |
327 | of_node_put(pe_dn); | |
328 | ||
329 | return request; | |
330 | } | |
331 | ||
94afa5a5 ME |
332 | static int check_msix_entries(struct pci_dev *pdev) |
333 | { | |
334 | struct msi_desc *entry; | |
335 | int expected; | |
336 | ||
337 | /* There's no way for us to express to firmware that we want | |
338 | * a discontiguous, or non-zero based, range of MSI-X entries. | |
339 | * So we must reject such requests. */ | |
340 | ||
341 | expected = 0; | |
2921d179 | 342 | for_each_pci_msi_entry(entry, pdev) { |
94afa5a5 ME |
343 | if (entry->msi_attrib.entry_nr != expected) { |
344 | pr_debug("rtas_msi: bad MSI-X entries.\n"); | |
345 | return -EINVAL; | |
346 | } | |
347 | expected++; | |
348 | } | |
349 | ||
350 | return 0; | |
351 | } | |
352 | ||
f1dd1531 BK |
353 | static void rtas_hack_32bit_msi_gen2(struct pci_dev *pdev) |
354 | { | |
355 | u32 addr_hi, addr_lo; | |
356 | ||
357 | /* | |
358 | * We should only get in here for IODA1 configs. This is based on the | |
359 | * fact that we using RTAS for MSIs, we don't have the 32 bit MSI RTAS | |
360 | * support, and we are in a PCIe Gen2 slot. | |
361 | */ | |
362 | dev_info(&pdev->dev, | |
363 | "rtas_msi: No 32 bit MSI firmware support, forcing 32 bit MSI\n"); | |
364 | pci_read_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, &addr_hi); | |
365 | addr_lo = 0xffff0000 | ((addr_hi >> (48 - 32)) << 4); | |
366 | pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_LO, addr_lo); | |
367 | pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, 0); | |
368 | } | |
369 | ||
752f5216 | 370 | static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec_in, int type) |
85f2bf9f ME |
371 | { |
372 | struct pci_dn *pdn; | |
6b2fd7ef | 373 | int hwirq, virq, i, quota, rc; |
85f2bf9f | 374 | struct msi_desc *entry; |
1db3e890 | 375 | struct msi_msg msg; |
752f5216 | 376 | int nvec = nvec_in; |
f1dd1531 | 377 | int use_32bit_msi_hack = 0; |
85f2bf9f | 378 | |
6b2fd7ef AG |
379 | if (type == PCI_CAP_ID_MSIX) |
380 | rc = check_req_msix(pdev, nvec); | |
381 | else | |
382 | rc = check_req_msi(pdev, nvec); | |
383 | ||
384 | if (rc) | |
385 | return rc; | |
386 | ||
387 | quota = msi_quota_for_device(pdev, nvec); | |
388 | ||
389 | if (quota && quota < nvec) | |
390 | return quota; | |
85f2bf9f | 391 | |
94afa5a5 ME |
392 | if (type == PCI_CAP_ID_MSIX && check_msix_entries(pdev)) |
393 | return -EINVAL; | |
394 | ||
752f5216 AB |
395 | /* |
396 | * Firmware currently refuse any non power of two allocation | |
397 | * so we round up if the quota will allow it. | |
398 | */ | |
399 | if (type == PCI_CAP_ID_MSIX) { | |
400 | int m = roundup_pow_of_two(nvec); | |
6b2fd7ef | 401 | quota = msi_quota_for_device(pdev, m); |
752f5216 AB |
402 | |
403 | if (quota >= m) | |
404 | nvec = m; | |
405 | } | |
406 | ||
6b2fd7ef AG |
407 | pdn = pci_get_pdn(pdev); |
408 | ||
85f2bf9f ME |
409 | /* |
410 | * Try the new more explicit firmware interface, if that fails fall | |
411 | * back to the old interface. The old interface is known to never | |
412 | * return MSI-Xs. | |
413 | */ | |
752f5216 | 414 | again: |
85f2bf9f | 415 | if (type == PCI_CAP_ID_MSI) { |
415072a0 | 416 | if (pdev->no_64bit_msi) { |
e61133dd | 417 | rc = rtas_change_msi(pdn, RTAS_CHANGE_32MSI_FN, nvec); |
f1dd1531 BK |
418 | if (rc < 0) { |
419 | /* | |
420 | * We only want to run the 32 bit MSI hack below if | |
421 | * the max bus speed is Gen2 speed | |
422 | */ | |
423 | if (pdev->bus->max_bus_speed != PCIE_SPEED_5_0GT) | |
424 | return rc; | |
425 | ||
426 | use_32bit_msi_hack = 1; | |
427 | } | |
428 | } else | |
429 | rc = -1; | |
430 | ||
431 | if (rc < 0) | |
e61133dd | 432 | rc = rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, nvec); |
85f2bf9f | 433 | |
f1dd1531 | 434 | if (rc < 0) { |
85f2bf9f ME |
435 | pr_debug("rtas_msi: trying the old firmware call.\n"); |
436 | rc = rtas_change_msi(pdn, RTAS_CHANGE_FN, nvec); | |
437 | } | |
f1dd1531 BK |
438 | |
439 | if (use_32bit_msi_hack && rc > 0) | |
440 | rtas_hack_32bit_msi_gen2(pdev); | |
85f2bf9f ME |
441 | } else |
442 | rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, nvec); | |
443 | ||
6071ed04 | 444 | if (rc != nvec) { |
752f5216 AB |
445 | if (nvec != nvec_in) { |
446 | nvec = nvec_in; | |
447 | goto again; | |
448 | } | |
85f2bf9f | 449 | pr_debug("rtas_msi: rtas_change_msi() failed\n"); |
fcbe8090 | 450 | return rc; |
85f2bf9f ME |
451 | } |
452 | ||
453 | i = 0; | |
2921d179 | 454 | for_each_pci_msi_entry(entry, pdev) { |
e27ed698 | 455 | hwirq = rtas_query_irq_number(pdn, i++); |
85f2bf9f | 456 | if (hwirq < 0) { |
85f2bf9f | 457 | pr_debug("rtas_msi: error (%d) getting hwirq\n", rc); |
fcbe8090 | 458 | return hwirq; |
85f2bf9f ME |
459 | } |
460 | ||
461 | virq = irq_create_mapping(NULL, hwirq); | |
462 | ||
ef24ba70 | 463 | if (!virq) { |
85f2bf9f | 464 | pr_debug("rtas_msi: Failed mapping hwirq %d\n", hwirq); |
fcbe8090 | 465 | return -ENOSPC; |
85f2bf9f ME |
466 | } |
467 | ||
468 | dev_dbg(&pdev->dev, "rtas_msi: allocated virq %d\n", virq); | |
ec775d0e | 469 | irq_set_msi_desc(virq, entry); |
1db3e890 ME |
470 | |
471 | /* Read config space back so we can restore after reset */ | |
891d4a48 | 472 | __pci_read_msi_msg(entry, &msg); |
1db3e890 | 473 | entry->msg = msg; |
85f2bf9f ME |
474 | } |
475 | ||
476 | return 0; | |
85f2bf9f ME |
477 | } |
478 | ||
479 | static void rtas_msi_pci_irq_fixup(struct pci_dev *pdev) | |
480 | { | |
481 | /* No LSI -> leave MSIs (if any) configured */ | |
ef24ba70 | 482 | if (!pdev->irq) { |
85f2bf9f ME |
483 | dev_dbg(&pdev->dev, "rtas_msi: no LSI, nothing to do.\n"); |
484 | return; | |
485 | } | |
486 | ||
487 | /* No MSI -> MSIs can't have been assigned by fw, leave LSI */ | |
649781f8 ME |
488 | if (check_req_msi(pdev, 1) && check_req_msix(pdev, 1)) { |
489 | dev_dbg(&pdev->dev, "rtas_msi: no req#msi/x, nothing to do.\n"); | |
85f2bf9f ME |
490 | return; |
491 | } | |
492 | ||
493 | dev_dbg(&pdev->dev, "rtas_msi: disabling existing MSI.\n"); | |
494 | rtas_disable_msi(pdev); | |
495 | } | |
496 | ||
497 | static int rtas_msi_init(void) | |
498 | { | |
1d14b875 DA |
499 | struct pci_controller *phb; |
500 | ||
85f2bf9f ME |
501 | query_token = rtas_token("ibm,query-interrupt-source-number"); |
502 | change_token = rtas_token("ibm,change-msi"); | |
503 | ||
504 | if ((query_token == RTAS_UNKNOWN_SERVICE) || | |
505 | (change_token == RTAS_UNKNOWN_SERVICE)) { | |
506 | pr_debug("rtas_msi: no RTAS tokens, no MSI support.\n"); | |
507 | return -1; | |
508 | } | |
509 | ||
510 | pr_debug("rtas_msi: Registering RTAS MSI callbacks.\n"); | |
511 | ||
1d14b875 DA |
512 | WARN_ON(pseries_pci_controller_ops.setup_msi_irqs); |
513 | pseries_pci_controller_ops.setup_msi_irqs = rtas_setup_msi_irqs; | |
514 | pseries_pci_controller_ops.teardown_msi_irqs = rtas_teardown_msi_irqs; | |
515 | ||
516 | list_for_each_entry(phb, &hose_list, list_node) { | |
517 | WARN_ON(phb->controller_ops.setup_msi_irqs); | |
518 | phb->controller_ops.setup_msi_irqs = rtas_setup_msi_irqs; | |
519 | phb->controller_ops.teardown_msi_irqs = rtas_teardown_msi_irqs; | |
520 | } | |
85f2bf9f ME |
521 | |
522 | WARN_ON(ppc_md.pci_irq_fixup); | |
523 | ppc_md.pci_irq_fixup = rtas_msi_pci_irq_fixup; | |
524 | ||
525 | return 0; | |
526 | } | |
8e83e905 | 527 | machine_arch_initcall(pseries, rtas_msi_init); |