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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
20static 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#define RTAS_CHANGE_32MSI_FN 5
28
29
30
31static int rtas_change_msi(struct pci_dn *pdn, u32 func, u32 num_irqs)
32{
33 u32 addr, seq_num, rtas_ret[3];
34 unsigned long buid;
35 int rc;
36
37 addr = rtas_config_addr(pdn->busno, pdn->devfn, 0);
38 buid = pdn->phb->buid;
39
40 seq_num = 1;
41 do {
42 if (func == RTAS_CHANGE_MSI_FN || func == RTAS_CHANGE_MSIX_FN ||
43 func == RTAS_CHANGE_32MSI_FN)
44 rc = rtas_call(change_token, 6, 4, rtas_ret, addr,
45 BUID_HI(buid), BUID_LO(buid),
46 func, num_irqs, seq_num);
47 else
48 rc = rtas_call(change_token, 6, 3, rtas_ret, addr,
49 BUID_HI(buid), BUID_LO(buid),
50 func, num_irqs, seq_num);
51
52 seq_num = rtas_ret[1];
53 } while (rtas_busy_delay(rc));
54
55
56
57
58
59 if (rc == 0)
60 rc = rtas_ret[0];
61 else if (rc > 0)
62 rc = -rc;
63
64 pr_debug("rtas_msi: ibm,change_msi(func=%d,num=%d), got %d rc = %d\n",
65 func, num_irqs, rtas_ret[0], rc);
66
67 return rc;
68}
69
70static void rtas_disable_msi(struct pci_dev *pdev)
71{
72 struct pci_dn *pdn;
73
74 pdn = pci_get_pdn(pdev);
75 if (!pdn)
76 return;
77
78
79
80
81 if (rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, 0) != 0) {
82
83
84
85
86 if (rtas_change_msi(pdn, RTAS_CHANGE_FN, 0) != 0) {
87 pr_debug("rtas_msi: Setting MSIs to 0 failed!\n");
88 }
89 }
90}
91
92static int rtas_query_irq_number(struct pci_dn *pdn, int offset)
93{
94 u32 addr, rtas_ret[2];
95 unsigned long buid;
96 int rc;
97
98 addr = rtas_config_addr(pdn->busno, pdn->devfn, 0);
99 buid = pdn->phb->buid;
100
101 do {
102 rc = rtas_call(query_token, 4, 3, rtas_ret, addr,
103 BUID_HI(buid), BUID_LO(buid), offset);
104 } while (rtas_busy_delay(rc));
105
106 if (rc) {
107 pr_debug("rtas_msi: error (%d) querying source number\n", rc);
108 return rc;
109 }
110
111 return rtas_ret[0];
112}
113
114static void rtas_teardown_msi_irqs(struct pci_dev *pdev)
115{
116 struct msi_desc *entry;
117
118 list_for_each_entry(entry, &pdev->msi_list, list) {
119 if (entry->irq == NO_IRQ)
120 continue;
121
122 irq_set_msi_desc(entry->irq, NULL);
123 irq_dispose_mapping(entry->irq);
124 }
125
126 rtas_disable_msi(pdev);
127}
128
129static int check_req(struct pci_dev *pdev, int nvec, char *prop_name)
130{
131 struct device_node *dn;
132 struct pci_dn *pdn;
133 const u32 *req_msi;
134
135 pdn = pci_get_pdn(pdev);
136 if (!pdn)
137 return -ENODEV;
138
139 dn = pdn->node;
140
141 req_msi = of_get_property(dn, prop_name, NULL);
142 if (!req_msi) {
143 pr_debug("rtas_msi: No %s on %s\n", prop_name, dn->full_name);
144 return -ENOENT;
145 }
146
147 if (*req_msi < nvec) {
148 pr_debug("rtas_msi: %s requests < %d MSIs\n", prop_name, nvec);
149
150 if (*req_msi == 0)
151 return -ENOSPC;
152
153 return *req_msi;
154 }
155
156 return 0;
157}
158
159static int check_req_msi(struct pci_dev *pdev, int nvec)
160{
161 return check_req(pdev, nvec, "ibm,req#msi");
162}
163
164static int check_req_msix(struct pci_dev *pdev, int nvec)
165{
166 return check_req(pdev, nvec, "ibm,req#msi-x");
167}
168
169
170
171static struct device_node *find_pe_total_msi(struct pci_dev *dev, int *total)
172{
173 struct device_node *dn;
174 const u32 *p;
175
176 dn = of_node_get(pci_device_to_OF_node(dev));
177 while (dn) {
178 p = of_get_property(dn, "ibm,pe-total-#msi", NULL);
179 if (p) {
180 pr_debug("rtas_msi: found prop on dn %s\n",
181 dn->full_name);
182 *total = *p;
183 return dn;
184 }
185
186 dn = of_get_next_parent(dn);
187 }
188
189 return NULL;
190}
191
192static struct device_node *find_pe_dn(struct pci_dev *dev, int *total)
193{
194 struct device_node *dn;
195 struct eeh_dev *edev;
196
197
198
199 dn = pci_device_to_OF_node(dev);
200 if (!dn)
201 return NULL;
202
203
204 edev = of_node_to_eeh_dev(dn);
205 if (edev->pe)
206 edev = list_first_entry(&edev->pe->edevs, struct eeh_dev, list);
207 dn = eeh_dev_to_of_node(edev);
208 if (!dn)
209 return NULL;
210
211
212 dn = of_get_parent(dn);
213 if (!dn)
214 return NULL;
215
216
217 *total = 8;
218 pr_debug("rtas_msi: using PE dn %s\n", dn->full_name);
219
220 return dn;
221}
222
223struct msi_counts {
224 struct device_node *requestor;
225 int num_devices;
226 int request;
227 int quota;
228 int spare;
229 int over_quota;
230};
231
232static void *count_non_bridge_devices(struct device_node *dn, void *data)
233{
234 struct msi_counts *counts = data;
235 const u32 *p;
236 u32 class;
237
238 pr_debug("rtas_msi: counting %s\n", dn->full_name);
239
240 p = of_get_property(dn, "class-code", NULL);
241 class = p ? *p : 0;
242
243 if ((class >> 8) != PCI_CLASS_BRIDGE_PCI)
244 counts->num_devices++;
245
246 return NULL;
247}
248
249static void *count_spare_msis(struct device_node *dn, void *data)
250{
251 struct msi_counts *counts = data;
252 const u32 *p;
253 int req;
254
255 if (dn == counts->requestor)
256 req = counts->request;
257 else {
258
259
260 req = 0;
261 p = of_get_property(dn, "ibm,req#msi", NULL);
262 if (p)
263 req = *p;
264
265 p = of_get_property(dn, "ibm,req#msi-x", NULL);
266 if (p)
267 req = max(req, (int)*p);
268 }
269
270 if (req < counts->quota)
271 counts->spare += counts->quota - req;
272 else if (req > counts->quota)
273 counts->over_quota++;
274
275 return NULL;
276}
277
278static int msi_quota_for_device(struct pci_dev *dev, int request)
279{
280 struct device_node *pe_dn;
281 struct msi_counts counts;
282 int total;
283
284 pr_debug("rtas_msi: calc quota for %s, request %d\n", pci_name(dev),
285 request);
286
287 pe_dn = find_pe_total_msi(dev, &total);
288 if (!pe_dn)
289 pe_dn = find_pe_dn(dev, &total);
290
291 if (!pe_dn) {
292 pr_err("rtas_msi: couldn't find PE for %s\n", pci_name(dev));
293 goto out;
294 }
295
296 pr_debug("rtas_msi: found PE %s\n", pe_dn->full_name);
297
298 memset(&counts, 0, sizeof(struct msi_counts));
299
300
301 traverse_pci_devices(pe_dn, count_non_bridge_devices, &counts);
302
303 if (counts.num_devices == 0) {
304 pr_err("rtas_msi: found 0 devices under PE for %s\n",
305 pci_name(dev));
306 goto out;
307 }
308
309 counts.quota = total / counts.num_devices;
310 if (request <= counts.quota)
311 goto out;
312
313
314 counts.requestor = pci_device_to_OF_node(dev);
315 counts.request = request;
316 traverse_pci_devices(pe_dn, count_spare_msis, &counts);
317
318
319
320 counts.spare += total % counts.num_devices;
321
322
323 if (counts.over_quota)
324 counts.quota += counts.spare / counts.over_quota;
325
326
327 request = min(counts.quota, request);
328
329 pr_debug("rtas_msi: request clamped to quota %d\n", request);
330out:
331 of_node_put(pe_dn);
332
333 return request;
334}
335
336static int rtas_msi_check_device(struct pci_dev *pdev, int nvec, int type)
337{
338 int quota, rc;
339
340 if (type == PCI_CAP_ID_MSIX)
341 rc = check_req_msix(pdev, nvec);
342 else
343 rc = check_req_msi(pdev, nvec);
344
345 if (rc)
346 return rc;
347
348 quota = msi_quota_for_device(pdev, nvec);
349
350 if (quota && quota < nvec)
351 return quota;
352
353 return 0;
354}
355
356static int check_msix_entries(struct pci_dev *pdev)
357{
358 struct msi_desc *entry;
359 int expected;
360
361
362
363
364
365 expected = 0;
366 list_for_each_entry(entry, &pdev->msi_list, list) {
367 if (entry->msi_attrib.entry_nr != expected) {
368 pr_debug("rtas_msi: bad MSI-X entries.\n");
369 return -EINVAL;
370 }
371 expected++;
372 }
373
374 return 0;
375}
376
377static void rtas_hack_32bit_msi_gen2(struct pci_dev *pdev)
378{
379 u32 addr_hi, addr_lo;
380
381
382
383
384
385
386 dev_info(&pdev->dev,
387 "rtas_msi: No 32 bit MSI firmware support, forcing 32 bit MSI\n");
388 pci_read_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, &addr_hi);
389 addr_lo = 0xffff0000 | ((addr_hi >> (48 - 32)) << 4);
390 pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_LO, addr_lo);
391 pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, 0);
392}
393
394static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec_in, int type)
395{
396 struct pci_dn *pdn;
397 int hwirq, virq, i, rc;
398 struct msi_desc *entry;
399 struct msi_msg msg;
400 int nvec = nvec_in;
401 int use_32bit_msi_hack = 0;
402
403 pdn = pci_get_pdn(pdev);
404 if (!pdn)
405 return -ENODEV;
406
407 if (type == PCI_CAP_ID_MSIX && check_msix_entries(pdev))
408 return -EINVAL;
409
410
411
412
413
414 if (type == PCI_CAP_ID_MSIX) {
415 int m = roundup_pow_of_two(nvec);
416 int quota = msi_quota_for_device(pdev, m);
417
418 if (quota >= m)
419 nvec = m;
420 }
421
422
423
424
425
426
427again:
428 if (type == PCI_CAP_ID_MSI) {
429 if (pdn->force_32bit_msi) {
430 rc = rtas_change_msi(pdn, RTAS_CHANGE_32MSI_FN, nvec);
431 if (rc < 0) {
432
433
434
435
436 if (pdev->bus->max_bus_speed != PCIE_SPEED_5_0GT)
437 return rc;
438
439 use_32bit_msi_hack = 1;
440 }
441 } else
442 rc = -1;
443
444 if (rc < 0)
445 rc = rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, nvec);
446
447 if (rc < 0) {
448 pr_debug("rtas_msi: trying the old firmware call.\n");
449 rc = rtas_change_msi(pdn, RTAS_CHANGE_FN, nvec);
450 }
451
452 if (use_32bit_msi_hack && rc > 0)
453 rtas_hack_32bit_msi_gen2(pdev);
454 } else
455 rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, nvec);
456
457 if (rc != nvec) {
458 if (nvec != nvec_in) {
459 nvec = nvec_in;
460 goto again;
461 }
462 pr_debug("rtas_msi: rtas_change_msi() failed\n");
463 return rc;
464 }
465
466 i = 0;
467 list_for_each_entry(entry, &pdev->msi_list, list) {
468 hwirq = rtas_query_irq_number(pdn, i++);
469 if (hwirq < 0) {
470 pr_debug("rtas_msi: error (%d) getting hwirq\n", rc);
471 return hwirq;
472 }
473
474 virq = irq_create_mapping(NULL, hwirq);
475
476 if (virq == NO_IRQ) {
477 pr_debug("rtas_msi: Failed mapping hwirq %d\n", hwirq);
478 return -ENOSPC;
479 }
480
481 dev_dbg(&pdev->dev, "rtas_msi: allocated virq %d\n", virq);
482 irq_set_msi_desc(virq, entry);
483
484
485 read_msi_msg(virq, &msg);
486 entry->msg = msg;
487 }
488
489 return 0;
490}
491
492static void rtas_msi_pci_irq_fixup(struct pci_dev *pdev)
493{
494
495 if (pdev->irq == NO_IRQ) {
496 dev_dbg(&pdev->dev, "rtas_msi: no LSI, nothing to do.\n");
497 return;
498 }
499
500
501 if (check_req_msi(pdev, 1) && check_req_msix(pdev, 1)) {
502 dev_dbg(&pdev->dev, "rtas_msi: no req#msi/x, nothing to do.\n");
503 return;
504 }
505
506 dev_dbg(&pdev->dev, "rtas_msi: disabling existing MSI.\n");
507 rtas_disable_msi(pdev);
508}
509
510static int rtas_msi_init(void)
511{
512 query_token = rtas_token("ibm,query-interrupt-source-number");
513 change_token = rtas_token("ibm,change-msi");
514
515 if ((query_token == RTAS_UNKNOWN_SERVICE) ||
516 (change_token == RTAS_UNKNOWN_SERVICE)) {
517 pr_debug("rtas_msi: no RTAS tokens, no MSI support.\n");
518 return -1;
519 }
520
521 pr_debug("rtas_msi: Registering RTAS MSI callbacks.\n");
522
523 WARN_ON(ppc_md.setup_msi_irqs);
524 ppc_md.setup_msi_irqs = rtas_setup_msi_irqs;
525 ppc_md.teardown_msi_irqs = rtas_teardown_msi_irqs;
526 ppc_md.msi_check_device = rtas_msi_check_device;
527
528 WARN_ON(ppc_md.pci_irq_fixup);
529 ppc_md.pci_irq_fixup = rtas_msi_pci_irq_fixup;
530
531 return 0;
532}
533arch_initcall(rtas_msi_init);
534
535