1 /*
2 * Intel I/OAT DMA Linux driver
3 * Copyright(c) 2007 - 2009 Intel Corporation.
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 * The full GNU General Public License is included in this distribution in
15 * the file called "COPYING".
16 *
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/pci.h>
21 #include <linux/smp.h>
22 #include <linux/interrupt.h>
23 #include <linux/dca.h>
24
25 /* either a kernel change is needed, or we need something like this in kernel */
26 #ifndef CONFIG_SMP
27 #include <asm/smp.h>
28 #undef cpu_physical_id
29 #define cpu_physical_id(cpu) (cpuid_ebx(1) >> 24)
30 #endif
31
32 #include "dma.h"
33 #include "registers.h"
34 #include "dma_v2.h"
35
36 /*
37 * Bit 7 of a tag map entry is the "valid" bit, if it is set then bits 0:6
38 * contain the bit number of the APIC ID to map into the DCA tag. If the valid
39 * bit is not set, then the value must be 0 or 1 and defines the bit in the tag.
40 */
41 #define DCA_TAG_MAP_VALID 0x80
42
43 #define DCA3_TAG_MAP_BIT_TO_INV 0x80
44 #define DCA3_TAG_MAP_BIT_TO_SEL 0x40
45 #define DCA3_TAG_MAP_LITERAL_VAL 0x1
46
47 #define DCA_TAG_MAP_MASK 0xDF
48
49 /* expected tag map bytes for I/OAT ver.2 */
50 #define DCA2_TAG_MAP_BYTE0 0x80
51 #define DCA2_TAG_MAP_BYTE1 0x0
52 #define DCA2_TAG_MAP_BYTE2 0x81
53 #define DCA2_TAG_MAP_BYTE3 0x82
54 #define DCA2_TAG_MAP_BYTE4 0x82
55
56 /* verify if tag map matches expected values */
dca2_tag_map_valid(u8 * tag_map)57 static inline int dca2_tag_map_valid(u8 *tag_map)
58 {
59 return ((tag_map[0] == DCA2_TAG_MAP_BYTE0) &&
60 (tag_map[1] == DCA2_TAG_MAP_BYTE1) &&
61 (tag_map[2] == DCA2_TAG_MAP_BYTE2) &&
62 (tag_map[3] == DCA2_TAG_MAP_BYTE3) &&
63 (tag_map[4] == DCA2_TAG_MAP_BYTE4));
64 }
65
66 /*
67 * "Legacy" DCA systems do not implement the DCA register set in the
68 * I/OAT device. Software needs direct support for their tag mappings.
69 */
70
71 #define APICID_BIT(x) (DCA_TAG_MAP_VALID | (x))
72 #define IOAT_TAG_MAP_LEN 8
73
74 static u8 ioat_tag_map_BNB[IOAT_TAG_MAP_LEN] = {
75 1, APICID_BIT(1), APICID_BIT(2), APICID_BIT(2), };
76 static u8 ioat_tag_map_SCNB[IOAT_TAG_MAP_LEN] = {
77 1, APICID_BIT(1), APICID_BIT(2), APICID_BIT(2), };
78 static u8 ioat_tag_map_CNB[IOAT_TAG_MAP_LEN] = {
79 1, APICID_BIT(1), APICID_BIT(3), APICID_BIT(4), APICID_BIT(2), };
80 static u8 ioat_tag_map_UNISYS[IOAT_TAG_MAP_LEN] = { 0 };
81
82 /* pack PCI B/D/F into a u16 */
dcaid_from_pcidev(struct pci_dev * pci)83 static inline u16 dcaid_from_pcidev(struct pci_dev *pci)
84 {
85 return (pci->bus->number << 8) | pci->devfn;
86 }
87
dca_enabled_in_bios(struct pci_dev * pdev)88 static int dca_enabled_in_bios(struct pci_dev *pdev)
89 {
90 /* CPUID level 9 returns DCA configuration */
91 /* Bit 0 indicates DCA enabled by the BIOS */
92 unsigned long cpuid_level_9;
93 int res;
94
95 cpuid_level_9 = cpuid_eax(9);
96 res = test_bit(0, &cpuid_level_9);
97 if (!res)
98 dev_dbg(&pdev->dev, "DCA is disabled in BIOS\n");
99
100 return res;
101 }
102
system_has_dca_enabled(struct pci_dev * pdev)103 int system_has_dca_enabled(struct pci_dev *pdev)
104 {
105 if (boot_cpu_has(X86_FEATURE_DCA))
106 return dca_enabled_in_bios(pdev);
107
108 dev_dbg(&pdev->dev, "boot cpu doesn't have X86_FEATURE_DCA\n");
109 return 0;
110 }
111
112 struct ioat_dca_slot {
113 struct pci_dev *pdev; /* requester device */
114 u16 rid; /* requester id, as used by IOAT */
115 };
116
117 #define IOAT_DCA_MAX_REQ 6
118 #define IOAT3_DCA_MAX_REQ 2
119
120 struct ioat_dca_priv {
121 void __iomem *iobase;
122 void __iomem *dca_base;
123 int max_requesters;
124 int requester_count;
125 u8 tag_map[IOAT_TAG_MAP_LEN];
126 struct ioat_dca_slot req_slots[0];
127 };
128
129 /* 5000 series chipset DCA Port Requester ID Table Entry Format
130 * [15:8] PCI-Express Bus Number
131 * [7:3] PCI-Express Device Number
132 * [2:0] PCI-Express Function Number
133 *
134 * 5000 series chipset DCA control register format
135 * [7:1] Reserved (0)
136 * [0] Ignore Function Number
137 */
138
ioat_dca_add_requester(struct dca_provider * dca,struct device * dev)139 static int ioat_dca_add_requester(struct dca_provider *dca, struct device *dev)
140 {
141 struct ioat_dca_priv *ioatdca = dca_priv(dca);
142 struct pci_dev *pdev;
143 int i;
144 u16 id;
145
146 /* This implementation only supports PCI-Express */
147 if (!dev_is_pci(dev))
148 return -ENODEV;
149 pdev = to_pci_dev(dev);
150 id = dcaid_from_pcidev(pdev);
151
152 if (ioatdca->requester_count == ioatdca->max_requesters)
153 return -ENODEV;
154
155 for (i = 0; i < ioatdca->max_requesters; i++) {
156 if (ioatdca->req_slots[i].pdev == NULL) {
157 /* found an empty slot */
158 ioatdca->requester_count++;
159 ioatdca->req_slots[i].pdev = pdev;
160 ioatdca->req_slots[i].rid = id;
161 writew(id, ioatdca->dca_base + (i * 4));
162 /* make sure the ignore function bit is off */
163 writeb(0, ioatdca->dca_base + (i * 4) + 2);
164 return i;
165 }
166 }
167 /* Error, ioatdma->requester_count is out of whack */
168 return -EFAULT;
169 }
170
ioat_dca_remove_requester(struct dca_provider * dca,struct device * dev)171 static int ioat_dca_remove_requester(struct dca_provider *dca,
172 struct device *dev)
173 {
174 struct ioat_dca_priv *ioatdca = dca_priv(dca);
175 struct pci_dev *pdev;
176 int i;
177
178 /* This implementation only supports PCI-Express */
179 if (!dev_is_pci(dev))
180 return -ENODEV;
181 pdev = to_pci_dev(dev);
182
183 for (i = 0; i < ioatdca->max_requesters; i++) {
184 if (ioatdca->req_slots[i].pdev == pdev) {
185 writew(0, ioatdca->dca_base + (i * 4));
186 ioatdca->req_slots[i].pdev = NULL;
187 ioatdca->req_slots[i].rid = 0;
188 ioatdca->requester_count--;
189 return i;
190 }
191 }
192 return -ENODEV;
193 }
194
ioat_dca_get_tag(struct dca_provider * dca,struct device * dev,int cpu)195 static u8 ioat_dca_get_tag(struct dca_provider *dca,
196 struct device *dev,
197 int cpu)
198 {
199 struct ioat_dca_priv *ioatdca = dca_priv(dca);
200 int i, apic_id, bit, value;
201 u8 entry, tag;
202
203 tag = 0;
204 apic_id = cpu_physical_id(cpu);
205
206 for (i = 0; i < IOAT_TAG_MAP_LEN; i++) {
207 entry = ioatdca->tag_map[i];
208 if (entry & DCA_TAG_MAP_VALID) {
209 bit = entry & ~DCA_TAG_MAP_VALID;
210 value = (apic_id & (1 << bit)) ? 1 : 0;
211 } else {
212 value = entry ? 1 : 0;
213 }
214 tag |= (value << i);
215 }
216 return tag;
217 }
218
ioat_dca_dev_managed(struct dca_provider * dca,struct device * dev)219 static int ioat_dca_dev_managed(struct dca_provider *dca,
220 struct device *dev)
221 {
222 struct ioat_dca_priv *ioatdca = dca_priv(dca);
223 struct pci_dev *pdev;
224 int i;
225
226 pdev = to_pci_dev(dev);
227 for (i = 0; i < ioatdca->max_requesters; i++) {
228 if (ioatdca->req_slots[i].pdev == pdev)
229 return 1;
230 }
231 return 0;
232 }
233
234 static struct dca_ops ioat_dca_ops = {
235 .add_requester = ioat_dca_add_requester,
236 .remove_requester = ioat_dca_remove_requester,
237 .get_tag = ioat_dca_get_tag,
238 .dev_managed = ioat_dca_dev_managed,
239 };
240
241
ioat_dca_init(struct pci_dev * pdev,void __iomem * iobase)242 struct dca_provider *ioat_dca_init(struct pci_dev *pdev, void __iomem *iobase)
243 {
244 struct dca_provider *dca;
245 struct ioat_dca_priv *ioatdca;
246 u8 *tag_map = NULL;
247 int i;
248 int err;
249 u8 version;
250 u8 max_requesters;
251
252 if (!system_has_dca_enabled(pdev))
253 return NULL;
254
255 /* I/OAT v1 systems must have a known tag_map to support DCA */
256 switch (pdev->vendor) {
257 case PCI_VENDOR_ID_INTEL:
258 switch (pdev->device) {
259 case PCI_DEVICE_ID_INTEL_IOAT:
260 tag_map = ioat_tag_map_BNB;
261 break;
262 case PCI_DEVICE_ID_INTEL_IOAT_CNB:
263 tag_map = ioat_tag_map_CNB;
264 break;
265 case PCI_DEVICE_ID_INTEL_IOAT_SCNB:
266 tag_map = ioat_tag_map_SCNB;
267 break;
268 }
269 break;
270 case PCI_VENDOR_ID_UNISYS:
271 switch (pdev->device) {
272 case PCI_DEVICE_ID_UNISYS_DMA_DIRECTOR:
273 tag_map = ioat_tag_map_UNISYS;
274 break;
275 }
276 break;
277 }
278 if (tag_map == NULL)
279 return NULL;
280
281 version = readb(iobase + IOAT_VER_OFFSET);
282 if (version == IOAT_VER_3_0)
283 max_requesters = IOAT3_DCA_MAX_REQ;
284 else
285 max_requesters = IOAT_DCA_MAX_REQ;
286
287 dca = alloc_dca_provider(&ioat_dca_ops,
288 sizeof(*ioatdca) +
289 (sizeof(struct ioat_dca_slot) * max_requesters));
290 if (!dca)
291 return NULL;
292
293 ioatdca = dca_priv(dca);
294 ioatdca->max_requesters = max_requesters;
295 ioatdca->dca_base = iobase + 0x54;
296
297 /* copy over the APIC ID to DCA tag mapping */
298 for (i = 0; i < IOAT_TAG_MAP_LEN; i++)
299 ioatdca->tag_map[i] = tag_map[i];
300
301 err = register_dca_provider(dca, &pdev->dev);
302 if (err) {
303 free_dca_provider(dca);
304 return NULL;
305 }
306
307 return dca;
308 }
309
310
ioat2_dca_add_requester(struct dca_provider * dca,struct device * dev)311 static int ioat2_dca_add_requester(struct dca_provider *dca, struct device *dev)
312 {
313 struct ioat_dca_priv *ioatdca = dca_priv(dca);
314 struct pci_dev *pdev;
315 int i;
316 u16 id;
317 u16 global_req_table;
318
319 /* This implementation only supports PCI-Express */
320 if (!dev_is_pci(dev))
321 return -ENODEV;
322 pdev = to_pci_dev(dev);
323 id = dcaid_from_pcidev(pdev);
324
325 if (ioatdca->requester_count == ioatdca->max_requesters)
326 return -ENODEV;
327
328 for (i = 0; i < ioatdca->max_requesters; i++) {
329 if (ioatdca->req_slots[i].pdev == NULL) {
330 /* found an empty slot */
331 ioatdca->requester_count++;
332 ioatdca->req_slots[i].pdev = pdev;
333 ioatdca->req_slots[i].rid = id;
334 global_req_table =
335 readw(ioatdca->dca_base + IOAT_DCA_GREQID_OFFSET);
336 writel(id | IOAT_DCA_GREQID_VALID,
337 ioatdca->iobase + global_req_table + (i * 4));
338 return i;
339 }
340 }
341 /* Error, ioatdma->requester_count is out of whack */
342 return -EFAULT;
343 }
344
ioat2_dca_remove_requester(struct dca_provider * dca,struct device * dev)345 static int ioat2_dca_remove_requester(struct dca_provider *dca,
346 struct device *dev)
347 {
348 struct ioat_dca_priv *ioatdca = dca_priv(dca);
349 struct pci_dev *pdev;
350 int i;
351 u16 global_req_table;
352
353 /* This implementation only supports PCI-Express */
354 if (!dev_is_pci(dev))
355 return -ENODEV;
356 pdev = to_pci_dev(dev);
357
358 for (i = 0; i < ioatdca->max_requesters; i++) {
359 if (ioatdca->req_slots[i].pdev == pdev) {
360 global_req_table =
361 readw(ioatdca->dca_base + IOAT_DCA_GREQID_OFFSET);
362 writel(0, ioatdca->iobase + global_req_table + (i * 4));
363 ioatdca->req_slots[i].pdev = NULL;
364 ioatdca->req_slots[i].rid = 0;
365 ioatdca->requester_count--;
366 return i;
367 }
368 }
369 return -ENODEV;
370 }
371
ioat2_dca_get_tag(struct dca_provider * dca,struct device * dev,int cpu)372 static u8 ioat2_dca_get_tag(struct dca_provider *dca,
373 struct device *dev,
374 int cpu)
375 {
376 u8 tag;
377
378 tag = ioat_dca_get_tag(dca, dev, cpu);
379 tag = (~tag) & 0x1F;
380 return tag;
381 }
382
383 static struct dca_ops ioat2_dca_ops = {
384 .add_requester = ioat2_dca_add_requester,
385 .remove_requester = ioat2_dca_remove_requester,
386 .get_tag = ioat2_dca_get_tag,
387 .dev_managed = ioat_dca_dev_managed,
388 };
389
ioat2_dca_count_dca_slots(void __iomem * iobase,u16 dca_offset)390 static int ioat2_dca_count_dca_slots(void __iomem *iobase, u16 dca_offset)
391 {
392 int slots = 0;
393 u32 req;
394 u16 global_req_table;
395
396 global_req_table = readw(iobase + dca_offset + IOAT_DCA_GREQID_OFFSET);
397 if (global_req_table == 0)
398 return 0;
399 do {
400 req = readl(iobase + global_req_table + (slots * sizeof(u32)));
401 slots++;
402 } while ((req & IOAT_DCA_GREQID_LASTID) == 0);
403
404 return slots;
405 }
406
ioat2_dca_init(struct pci_dev * pdev,void __iomem * iobase)407 struct dca_provider *ioat2_dca_init(struct pci_dev *pdev, void __iomem *iobase)
408 {
409 struct dca_provider *dca;
410 struct ioat_dca_priv *ioatdca;
411 int slots;
412 int i;
413 int err;
414 u32 tag_map;
415 u16 dca_offset;
416 u16 csi_fsb_control;
417 u16 pcie_control;
418 u8 bit;
419
420 if (!system_has_dca_enabled(pdev))
421 return NULL;
422
423 dca_offset = readw(iobase + IOAT_DCAOFFSET_OFFSET);
424 if (dca_offset == 0)
425 return NULL;
426
427 slots = ioat2_dca_count_dca_slots(iobase, dca_offset);
428 if (slots == 0)
429 return NULL;
430
431 dca = alloc_dca_provider(&ioat2_dca_ops,
432 sizeof(*ioatdca)
433 + (sizeof(struct ioat_dca_slot) * slots));
434 if (!dca)
435 return NULL;
436
437 ioatdca = dca_priv(dca);
438 ioatdca->iobase = iobase;
439 ioatdca->dca_base = iobase + dca_offset;
440 ioatdca->max_requesters = slots;
441
442 /* some bios might not know to turn these on */
443 csi_fsb_control = readw(ioatdca->dca_base + IOAT_FSB_CAP_ENABLE_OFFSET);
444 if ((csi_fsb_control & IOAT_FSB_CAP_ENABLE_PREFETCH) == 0) {
445 csi_fsb_control |= IOAT_FSB_CAP_ENABLE_PREFETCH;
446 writew(csi_fsb_control,
447 ioatdca->dca_base + IOAT_FSB_CAP_ENABLE_OFFSET);
448 }
449 pcie_control = readw(ioatdca->dca_base + IOAT_PCI_CAP_ENABLE_OFFSET);
450 if ((pcie_control & IOAT_PCI_CAP_ENABLE_MEMWR) == 0) {
451 pcie_control |= IOAT_PCI_CAP_ENABLE_MEMWR;
452 writew(pcie_control,
453 ioatdca->dca_base + IOAT_PCI_CAP_ENABLE_OFFSET);
454 }
455
456
457 /* TODO version, compatibility and configuration checks */
458
459 /* copy out the APIC to DCA tag map */
460 tag_map = readl(ioatdca->dca_base + IOAT_APICID_TAG_MAP_OFFSET);
461 for (i = 0; i < 5; i++) {
462 bit = (tag_map >> (4 * i)) & 0x0f;
463 if (bit < 8)
464 ioatdca->tag_map[i] = bit | DCA_TAG_MAP_VALID;
465 else
466 ioatdca->tag_map[i] = 0;
467 }
468
469 if (!dca2_tag_map_valid(ioatdca->tag_map)) {
470 WARN_TAINT_ONCE(1, TAINT_FIRMWARE_WORKAROUND,
471 "%s %s: APICID_TAG_MAP set incorrectly by BIOS, disabling DCA\n",
472 dev_driver_string(&pdev->dev),
473 dev_name(&pdev->dev));
474 free_dca_provider(dca);
475 return NULL;
476 }
477
478 err = register_dca_provider(dca, &pdev->dev);
479 if (err) {
480 free_dca_provider(dca);
481 return NULL;
482 }
483
484 return dca;
485 }
486
ioat3_dca_add_requester(struct dca_provider * dca,struct device * dev)487 static int ioat3_dca_add_requester(struct dca_provider *dca, struct device *dev)
488 {
489 struct ioat_dca_priv *ioatdca = dca_priv(dca);
490 struct pci_dev *pdev;
491 int i;
492 u16 id;
493 u16 global_req_table;
494
495 /* This implementation only supports PCI-Express */
496 if (!dev_is_pci(dev))
497 return -ENODEV;
498 pdev = to_pci_dev(dev);
499 id = dcaid_from_pcidev(pdev);
500
501 if (ioatdca->requester_count == ioatdca->max_requesters)
502 return -ENODEV;
503
504 for (i = 0; i < ioatdca->max_requesters; i++) {
505 if (ioatdca->req_slots[i].pdev == NULL) {
506 /* found an empty slot */
507 ioatdca->requester_count++;
508 ioatdca->req_slots[i].pdev = pdev;
509 ioatdca->req_slots[i].rid = id;
510 global_req_table =
511 readw(ioatdca->dca_base + IOAT3_DCA_GREQID_OFFSET);
512 writel(id | IOAT_DCA_GREQID_VALID,
513 ioatdca->iobase + global_req_table + (i * 4));
514 return i;
515 }
516 }
517 /* Error, ioatdma->requester_count is out of whack */
518 return -EFAULT;
519 }
520
ioat3_dca_remove_requester(struct dca_provider * dca,struct device * dev)521 static int ioat3_dca_remove_requester(struct dca_provider *dca,
522 struct device *dev)
523 {
524 struct ioat_dca_priv *ioatdca = dca_priv(dca);
525 struct pci_dev *pdev;
526 int i;
527 u16 global_req_table;
528
529 /* This implementation only supports PCI-Express */
530 if (!dev_is_pci(dev))
531 return -ENODEV;
532 pdev = to_pci_dev(dev);
533
534 for (i = 0; i < ioatdca->max_requesters; i++) {
535 if (ioatdca->req_slots[i].pdev == pdev) {
536 global_req_table =
537 readw(ioatdca->dca_base + IOAT3_DCA_GREQID_OFFSET);
538 writel(0, ioatdca->iobase + global_req_table + (i * 4));
539 ioatdca->req_slots[i].pdev = NULL;
540 ioatdca->req_slots[i].rid = 0;
541 ioatdca->requester_count--;
542 return i;
543 }
544 }
545 return -ENODEV;
546 }
547
ioat3_dca_get_tag(struct dca_provider * dca,struct device * dev,int cpu)548 static u8 ioat3_dca_get_tag(struct dca_provider *dca,
549 struct device *dev,
550 int cpu)
551 {
552 u8 tag;
553
554 struct ioat_dca_priv *ioatdca = dca_priv(dca);
555 int i, apic_id, bit, value;
556 u8 entry;
557
558 tag = 0;
559 apic_id = cpu_physical_id(cpu);
560
561 for (i = 0; i < IOAT_TAG_MAP_LEN; i++) {
562 entry = ioatdca->tag_map[i];
563 if (entry & DCA3_TAG_MAP_BIT_TO_SEL) {
564 bit = entry &
565 ~(DCA3_TAG_MAP_BIT_TO_SEL | DCA3_TAG_MAP_BIT_TO_INV);
566 value = (apic_id & (1 << bit)) ? 1 : 0;
567 } else if (entry & DCA3_TAG_MAP_BIT_TO_INV) {
568 bit = entry & ~DCA3_TAG_MAP_BIT_TO_INV;
569 value = (apic_id & (1 << bit)) ? 0 : 1;
570 } else {
571 value = (entry & DCA3_TAG_MAP_LITERAL_VAL) ? 1 : 0;
572 }
573 tag |= (value << i);
574 }
575
576 return tag;
577 }
578
579 static struct dca_ops ioat3_dca_ops = {
580 .add_requester = ioat3_dca_add_requester,
581 .remove_requester = ioat3_dca_remove_requester,
582 .get_tag = ioat3_dca_get_tag,
583 .dev_managed = ioat_dca_dev_managed,
584 };
585
ioat3_dca_count_dca_slots(void * iobase,u16 dca_offset)586 static int ioat3_dca_count_dca_slots(void *iobase, u16 dca_offset)
587 {
588 int slots = 0;
589 u32 req;
590 u16 global_req_table;
591
592 global_req_table = readw(iobase + dca_offset + IOAT3_DCA_GREQID_OFFSET);
593 if (global_req_table == 0)
594 return 0;
595
596 do {
597 req = readl(iobase + global_req_table + (slots * sizeof(u32)));
598 slots++;
599 } while ((req & IOAT_DCA_GREQID_LASTID) == 0);
600
601 return slots;
602 }
603
dca3_tag_map_invalid(u8 * tag_map)604 static inline int dca3_tag_map_invalid(u8 *tag_map)
605 {
606 /*
607 * If the tag map is not programmed by the BIOS the default is:
608 * 0x80 0x80 0x80 0x80 0x80 0x00 0x00 0x00
609 *
610 * This an invalid map and will result in only 2 possible tags
611 * 0x1F and 0x00. 0x00 is an invalid DCA tag so we know that
612 * this entire definition is invalid.
613 */
614 return ((tag_map[0] == DCA_TAG_MAP_VALID) &&
615 (tag_map[1] == DCA_TAG_MAP_VALID) &&
616 (tag_map[2] == DCA_TAG_MAP_VALID) &&
617 (tag_map[3] == DCA_TAG_MAP_VALID) &&
618 (tag_map[4] == DCA_TAG_MAP_VALID));
619 }
620
ioat3_dca_init(struct pci_dev * pdev,void __iomem * iobase)621 struct dca_provider *ioat3_dca_init(struct pci_dev *pdev, void __iomem *iobase)
622 {
623 struct dca_provider *dca;
624 struct ioat_dca_priv *ioatdca;
625 int slots;
626 int i;
627 int err;
628 u16 dca_offset;
629 u16 csi_fsb_control;
630 u16 pcie_control;
631 u8 bit;
632
633 union {
634 u64 full;
635 struct {
636 u32 low;
637 u32 high;
638 };
639 } tag_map;
640
641 if (!system_has_dca_enabled(pdev))
642 return NULL;
643
644 dca_offset = readw(iobase + IOAT_DCAOFFSET_OFFSET);
645 if (dca_offset == 0)
646 return NULL;
647
648 slots = ioat3_dca_count_dca_slots(iobase, dca_offset);
649 if (slots == 0)
650 return NULL;
651
652 dca = alloc_dca_provider(&ioat3_dca_ops,
653 sizeof(*ioatdca)
654 + (sizeof(struct ioat_dca_slot) * slots));
655 if (!dca)
656 return NULL;
657
658 ioatdca = dca_priv(dca);
659 ioatdca->iobase = iobase;
660 ioatdca->dca_base = iobase + dca_offset;
661 ioatdca->max_requesters = slots;
662
663 /* some bios might not know to turn these on */
664 csi_fsb_control = readw(ioatdca->dca_base + IOAT3_CSI_CONTROL_OFFSET);
665 if ((csi_fsb_control & IOAT3_CSI_CONTROL_PREFETCH) == 0) {
666 csi_fsb_control |= IOAT3_CSI_CONTROL_PREFETCH;
667 writew(csi_fsb_control,
668 ioatdca->dca_base + IOAT3_CSI_CONTROL_OFFSET);
669 }
670 pcie_control = readw(ioatdca->dca_base + IOAT3_PCI_CONTROL_OFFSET);
671 if ((pcie_control & IOAT3_PCI_CONTROL_MEMWR) == 0) {
672 pcie_control |= IOAT3_PCI_CONTROL_MEMWR;
673 writew(pcie_control,
674 ioatdca->dca_base + IOAT3_PCI_CONTROL_OFFSET);
675 }
676
677
678 /* TODO version, compatibility and configuration checks */
679
680 /* copy out the APIC to DCA tag map */
681 tag_map.low =
682 readl(ioatdca->dca_base + IOAT3_APICID_TAG_MAP_OFFSET_LOW);
683 tag_map.high =
684 readl(ioatdca->dca_base + IOAT3_APICID_TAG_MAP_OFFSET_HIGH);
685 for (i = 0; i < 8; i++) {
686 bit = tag_map.full >> (8 * i);
687 ioatdca->tag_map[i] = bit & DCA_TAG_MAP_MASK;
688 }
689
690 if (dca3_tag_map_invalid(ioatdca->tag_map)) {
691 WARN_TAINT_ONCE(1, TAINT_FIRMWARE_WORKAROUND,
692 "%s %s: APICID_TAG_MAP set incorrectly by BIOS, disabling DCA\n",
693 dev_driver_string(&pdev->dev),
694 dev_name(&pdev->dev));
695 free_dca_provider(dca);
696 return NULL;
697 }
698
699 err = register_dca_provider(dca, &pdev->dev);
700 if (err) {
701 free_dca_provider(dca);
702 return NULL;
703 }
704
705 return dca;
706 }
707