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 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
17 *
18 * The full GNU General Public License is included in this distribution in
19 * the file called "COPYING".
20 *
21 */
22
23 #include <linux/kernel.h>
24 #include <linux/pci.h>
25 #include <linux/smp.h>
26 #include <linux/interrupt.h>
27 #include <linux/dca.h>
28
29 /* either a kernel change is needed, or we need something like this in kernel */
30 #ifndef CONFIG_SMP
31 #include <asm/smp.h>
32 #undef cpu_physical_id
33 #define cpu_physical_id(cpu) (cpuid_ebx(1) >> 24)
34 #endif
35
36 #include "ioatdma.h"
37 #include "ioatdma_registers.h"
38
39 /*
40 * Bit 7 of a tag map entry is the "valid" bit, if it is set then bits 0:6
41 * contain the bit number of the APIC ID to map into the DCA tag. If the valid
42 * bit is not set, then the value must be 0 or 1 and defines the bit in the tag.
43 */
44 #define DCA_TAG_MAP_VALID 0x80
45
46 #define DCA3_TAG_MAP_BIT_TO_INV 0x80
47 #define DCA3_TAG_MAP_BIT_TO_SEL 0x40
48 #define DCA3_TAG_MAP_LITERAL_VAL 0x1
49
50 #define DCA_TAG_MAP_MASK 0xDF
51
52 /* expected tag map bytes for I/OAT ver.2 */
53 #define DCA2_TAG_MAP_BYTE0 0x80
54 #define DCA2_TAG_MAP_BYTE1 0x0
55 #define DCA2_TAG_MAP_BYTE2 0x81
56 #define DCA2_TAG_MAP_BYTE3 0x82
57 #define DCA2_TAG_MAP_BYTE4 0x82
58
59 /* verify if tag map matches expected values */
dca2_tag_map_valid(u8 * tag_map)60 static inline int dca2_tag_map_valid(u8 *tag_map)
61 {
62 return ((tag_map[0] == DCA2_TAG_MAP_BYTE0) &&
63 (tag_map[1] == DCA2_TAG_MAP_BYTE1) &&
64 (tag_map[2] == DCA2_TAG_MAP_BYTE2) &&
65 (tag_map[3] == DCA2_TAG_MAP_BYTE3) &&
66 (tag_map[4] == DCA2_TAG_MAP_BYTE4));
67 }
68
69 /*
70 * "Legacy" DCA systems do not implement the DCA register set in the
71 * I/OAT device. Software needs direct support for their tag mappings.
72 */
73
74 #define APICID_BIT(x) (DCA_TAG_MAP_VALID | (x))
75 #define IOAT_TAG_MAP_LEN 8
76
77 static u8 ioat_tag_map_BNB[IOAT_TAG_MAP_LEN] = {
78 1, APICID_BIT(1), APICID_BIT(2), APICID_BIT(2), };
79 static u8 ioat_tag_map_SCNB[IOAT_TAG_MAP_LEN] = {
80 1, APICID_BIT(1), APICID_BIT(2), APICID_BIT(2), };
81 static u8 ioat_tag_map_CNB[IOAT_TAG_MAP_LEN] = {
82 1, APICID_BIT(1), APICID_BIT(3), APICID_BIT(4), APICID_BIT(2), };
83 static u8 ioat_tag_map_UNISYS[IOAT_TAG_MAP_LEN] = { 0 };
84
85 /* pack PCI B/D/F into a u16 */
dcaid_from_pcidev(struct pci_dev * pci)86 static inline u16 dcaid_from_pcidev(struct pci_dev *pci)
87 {
88 return (pci->bus->number << 8) | pci->devfn;
89 }
90
dca_enabled_in_bios(struct pci_dev * pdev)91 static int dca_enabled_in_bios(struct pci_dev *pdev)
92 {
93 /* CPUID level 9 returns DCA configuration */
94 /* Bit 0 indicates DCA enabled by the BIOS */
95 unsigned long cpuid_level_9;
96 int res;
97
98 cpuid_level_9 = cpuid_eax(9);
99 res = test_bit(0, &cpuid_level_9);
100 if (!res)
101 dev_err(&pdev->dev, "DCA is disabled in BIOS\n");
102
103 return res;
104 }
105
system_has_dca_enabled(struct pci_dev * pdev)106 static int system_has_dca_enabled(struct pci_dev *pdev)
107 {
108 if (boot_cpu_has(X86_FEATURE_DCA))
109 return dca_enabled_in_bios(pdev);
110
111 dev_err(&pdev->dev, "boot cpu doesn't have X86_FEATURE_DCA\n");
112 return 0;
113 }
114
115 struct ioat_dca_slot {
116 struct pci_dev *pdev; /* requester device */
117 u16 rid; /* requester id, as used by IOAT */
118 };
119
120 #define IOAT_DCA_MAX_REQ 6
121 #define IOAT3_DCA_MAX_REQ 2
122
123 struct ioat_dca_priv {
124 void __iomem *iobase;
125 void __iomem *dca_base;
126 int max_requesters;
127 int requester_count;
128 u8 tag_map[IOAT_TAG_MAP_LEN];
129 struct ioat_dca_slot req_slots[0];
130 };
131
132 /* 5000 series chipset DCA Port Requester ID Table Entry Format
133 * [15:8] PCI-Express Bus Number
134 * [7:3] PCI-Express Device Number
135 * [2:0] PCI-Express Function Number
136 *
137 * 5000 series chipset DCA control register format
138 * [7:1] Reserved (0)
139 * [0] Ignore Function Number
140 */
141
ioat_dca_add_requester(struct dca_provider * dca,struct device * dev)142 static int ioat_dca_add_requester(struct dca_provider *dca, struct device *dev)
143 {
144 struct ioat_dca_priv *ioatdca = dca_priv(dca);
145 struct pci_dev *pdev;
146 int i;
147 u16 id;
148
149 /* This implementation only supports PCI-Express */
150 if (dev->bus != &pci_bus_type)
151 return -ENODEV;
152 pdev = to_pci_dev(dev);
153 id = dcaid_from_pcidev(pdev);
154
155 if (ioatdca->requester_count == ioatdca->max_requesters)
156 return -ENODEV;
157
158 for (i = 0; i < ioatdca->max_requesters; i++) {
159 if (ioatdca->req_slots[i].pdev == NULL) {
160 /* found an empty slot */
161 ioatdca->requester_count++;
162 ioatdca->req_slots[i].pdev = pdev;
163 ioatdca->req_slots[i].rid = id;
164 writew(id, ioatdca->dca_base + (i * 4));
165 /* make sure the ignore function bit is off */
166 writeb(0, ioatdca->dca_base + (i * 4) + 2);
167 return i;
168 }
169 }
170 /* Error, ioatdma->requester_count is out of whack */
171 return -EFAULT;
172 }
173
ioat_dca_remove_requester(struct dca_provider * dca,struct device * dev)174 static int ioat_dca_remove_requester(struct dca_provider *dca,
175 struct device *dev)
176 {
177 struct ioat_dca_priv *ioatdca = dca_priv(dca);
178 struct pci_dev *pdev;
179 int i;
180
181 /* This implementation only supports PCI-Express */
182 if (dev->bus != &pci_bus_type)
183 return -ENODEV;
184 pdev = to_pci_dev(dev);
185
186 for (i = 0; i < ioatdca->max_requesters; i++) {
187 if (ioatdca->req_slots[i].pdev == pdev) {
188 writew(0, ioatdca->dca_base + (i * 4));
189 ioatdca->req_slots[i].pdev = NULL;
190 ioatdca->req_slots[i].rid = 0;
191 ioatdca->requester_count--;
192 return i;
193 }
194 }
195 return -ENODEV;
196 }
197
ioat_dca_get_tag(struct dca_provider * dca,struct device * dev,int cpu)198 static u8 ioat_dca_get_tag(struct dca_provider *dca,
199 struct device *dev,
200 int cpu)
201 {
202 struct ioat_dca_priv *ioatdca = dca_priv(dca);
203 int i, apic_id, bit, value;
204 u8 entry, tag;
205
206 tag = 0;
207 apic_id = cpu_physical_id(cpu);
208
209 for (i = 0; i < IOAT_TAG_MAP_LEN; i++) {
210 entry = ioatdca->tag_map[i];
211 if (entry & DCA_TAG_MAP_VALID) {
212 bit = entry & ~DCA_TAG_MAP_VALID;
213 value = (apic_id & (1 << bit)) ? 1 : 0;
214 } else {
215 value = entry ? 1 : 0;
216 }
217 tag |= (value << i);
218 }
219 return tag;
220 }
221
ioat_dca_dev_managed(struct dca_provider * dca,struct device * dev)222 static int ioat_dca_dev_managed(struct dca_provider *dca,
223 struct device *dev)
224 {
225 struct ioat_dca_priv *ioatdca = dca_priv(dca);
226 struct pci_dev *pdev;
227 int i;
228
229 pdev = to_pci_dev(dev);
230 for (i = 0; i < ioatdca->max_requesters; i++) {
231 if (ioatdca->req_slots[i].pdev == pdev)
232 return 1;
233 }
234 return 0;
235 }
236
237 static struct dca_ops ioat_dca_ops = {
238 .add_requester = ioat_dca_add_requester,
239 .remove_requester = ioat_dca_remove_requester,
240 .get_tag = ioat_dca_get_tag,
241 .dev_managed = ioat_dca_dev_managed,
242 };
243
244
ioat_dca_init(struct pci_dev * pdev,void __iomem * iobase)245 struct dca_provider *ioat_dca_init(struct pci_dev *pdev, void __iomem *iobase)
246 {
247 struct dca_provider *dca;
248 struct ioat_dca_priv *ioatdca;
249 u8 *tag_map = NULL;
250 int i;
251 int err;
252 u8 version;
253 u8 max_requesters;
254
255 if (!system_has_dca_enabled(pdev))
256 return NULL;
257
258 /* I/OAT v1 systems must have a known tag_map to support DCA */
259 switch (pdev->vendor) {
260 case PCI_VENDOR_ID_INTEL:
261 switch (pdev->device) {
262 case PCI_DEVICE_ID_INTEL_IOAT:
263 tag_map = ioat_tag_map_BNB;
264 break;
265 case PCI_DEVICE_ID_INTEL_IOAT_CNB:
266 tag_map = ioat_tag_map_CNB;
267 break;
268 case PCI_DEVICE_ID_INTEL_IOAT_SCNB:
269 tag_map = ioat_tag_map_SCNB;
270 break;
271 }
272 break;
273 case PCI_VENDOR_ID_UNISYS:
274 switch (pdev->device) {
275 case PCI_DEVICE_ID_UNISYS_DMA_DIRECTOR:
276 tag_map = ioat_tag_map_UNISYS;
277 break;
278 }
279 break;
280 }
281 if (tag_map == NULL)
282 return NULL;
283
284 version = readb(iobase + IOAT_VER_OFFSET);
285 if (version == IOAT_VER_3_0)
286 max_requesters = IOAT3_DCA_MAX_REQ;
287 else
288 max_requesters = IOAT_DCA_MAX_REQ;
289
290 dca = alloc_dca_provider(&ioat_dca_ops,
291 sizeof(*ioatdca) +
292 (sizeof(struct ioat_dca_slot) * max_requesters));
293 if (!dca)
294 return NULL;
295
296 ioatdca = dca_priv(dca);
297 ioatdca->max_requesters = max_requesters;
298 ioatdca->dca_base = iobase + 0x54;
299
300 /* copy over the APIC ID to DCA tag mapping */
301 for (i = 0; i < IOAT_TAG_MAP_LEN; i++)
302 ioatdca->tag_map[i] = tag_map[i];
303
304 err = register_dca_provider(dca, &pdev->dev);
305 if (err) {
306 free_dca_provider(dca);
307 return NULL;
308 }
309
310 return dca;
311 }
312
313
ioat2_dca_add_requester(struct dca_provider * dca,struct device * dev)314 static int ioat2_dca_add_requester(struct dca_provider *dca, struct device *dev)
315 {
316 struct ioat_dca_priv *ioatdca = dca_priv(dca);
317 struct pci_dev *pdev;
318 int i;
319 u16 id;
320 u16 global_req_table;
321
322 /* This implementation only supports PCI-Express */
323 if (dev->bus != &pci_bus_type)
324 return -ENODEV;
325 pdev = to_pci_dev(dev);
326 id = dcaid_from_pcidev(pdev);
327
328 if (ioatdca->requester_count == ioatdca->max_requesters)
329 return -ENODEV;
330
331 for (i = 0; i < ioatdca->max_requesters; i++) {
332 if (ioatdca->req_slots[i].pdev == NULL) {
333 /* found an empty slot */
334 ioatdca->requester_count++;
335 ioatdca->req_slots[i].pdev = pdev;
336 ioatdca->req_slots[i].rid = id;
337 global_req_table =
338 readw(ioatdca->dca_base + IOAT_DCA_GREQID_OFFSET);
339 writel(id | IOAT_DCA_GREQID_VALID,
340 ioatdca->iobase + global_req_table + (i * 4));
341 return i;
342 }
343 }
344 /* Error, ioatdma->requester_count is out of whack */
345 return -EFAULT;
346 }
347
ioat2_dca_remove_requester(struct dca_provider * dca,struct device * dev)348 static int ioat2_dca_remove_requester(struct dca_provider *dca,
349 struct device *dev)
350 {
351 struct ioat_dca_priv *ioatdca = dca_priv(dca);
352 struct pci_dev *pdev;
353 int i;
354 u16 global_req_table;
355
356 /* This implementation only supports PCI-Express */
357 if (dev->bus != &pci_bus_type)
358 return -ENODEV;
359 pdev = to_pci_dev(dev);
360
361 for (i = 0; i < ioatdca->max_requesters; i++) {
362 if (ioatdca->req_slots[i].pdev == pdev) {
363 global_req_table =
364 readw(ioatdca->dca_base + IOAT_DCA_GREQID_OFFSET);
365 writel(0, ioatdca->iobase + global_req_table + (i * 4));
366 ioatdca->req_slots[i].pdev = NULL;
367 ioatdca->req_slots[i].rid = 0;
368 ioatdca->requester_count--;
369 return i;
370 }
371 }
372 return -ENODEV;
373 }
374
ioat2_dca_get_tag(struct dca_provider * dca,struct device * dev,int cpu)375 static u8 ioat2_dca_get_tag(struct dca_provider *dca,
376 struct device *dev,
377 int cpu)
378 {
379 u8 tag;
380
381 tag = ioat_dca_get_tag(dca, dev, cpu);
382 tag = (~tag) & 0x1F;
383 return tag;
384 }
385
386 static struct dca_ops ioat2_dca_ops = {
387 .add_requester = ioat2_dca_add_requester,
388 .remove_requester = ioat2_dca_remove_requester,
389 .get_tag = ioat2_dca_get_tag,
390 .dev_managed = ioat_dca_dev_managed,
391 };
392
ioat2_dca_count_dca_slots(void __iomem * iobase,u16 dca_offset)393 static int ioat2_dca_count_dca_slots(void __iomem *iobase, u16 dca_offset)
394 {
395 int slots = 0;
396 u32 req;
397 u16 global_req_table;
398
399 global_req_table = readw(iobase + dca_offset + IOAT_DCA_GREQID_OFFSET);
400 if (global_req_table == 0)
401 return 0;
402 do {
403 req = readl(iobase + global_req_table + (slots * sizeof(u32)));
404 slots++;
405 } while ((req & IOAT_DCA_GREQID_LASTID) == 0);
406
407 return slots;
408 }
409
ioat2_dca_init(struct pci_dev * pdev,void __iomem * iobase)410 struct dca_provider *ioat2_dca_init(struct pci_dev *pdev, void __iomem *iobase)
411 {
412 struct dca_provider *dca;
413 struct ioat_dca_priv *ioatdca;
414 int slots;
415 int i;
416 int err;
417 u32 tag_map;
418 u16 dca_offset;
419 u16 csi_fsb_control;
420 u16 pcie_control;
421 u8 bit;
422
423 if (!system_has_dca_enabled(pdev))
424 return NULL;
425
426 dca_offset = readw(iobase + IOAT_DCAOFFSET_OFFSET);
427 if (dca_offset == 0)
428 return NULL;
429
430 slots = ioat2_dca_count_dca_slots(iobase, dca_offset);
431 if (slots == 0)
432 return NULL;
433
434 dca = alloc_dca_provider(&ioat2_dca_ops,
435 sizeof(*ioatdca)
436 + (sizeof(struct ioat_dca_slot) * slots));
437 if (!dca)
438 return NULL;
439
440 ioatdca = dca_priv(dca);
441 ioatdca->iobase = iobase;
442 ioatdca->dca_base = iobase + dca_offset;
443 ioatdca->max_requesters = slots;
444
445 /* some bios might not know to turn these on */
446 csi_fsb_control = readw(ioatdca->dca_base + IOAT_FSB_CAP_ENABLE_OFFSET);
447 if ((csi_fsb_control & IOAT_FSB_CAP_ENABLE_PREFETCH) == 0) {
448 csi_fsb_control |= IOAT_FSB_CAP_ENABLE_PREFETCH;
449 writew(csi_fsb_control,
450 ioatdca->dca_base + IOAT_FSB_CAP_ENABLE_OFFSET);
451 }
452 pcie_control = readw(ioatdca->dca_base + IOAT_PCI_CAP_ENABLE_OFFSET);
453 if ((pcie_control & IOAT_PCI_CAP_ENABLE_MEMWR) == 0) {
454 pcie_control |= IOAT_PCI_CAP_ENABLE_MEMWR;
455 writew(pcie_control,
456 ioatdca->dca_base + IOAT_PCI_CAP_ENABLE_OFFSET);
457 }
458
459
460 /* TODO version, compatibility and configuration checks */
461
462 /* copy out the APIC to DCA tag map */
463 tag_map = readl(ioatdca->dca_base + IOAT_APICID_TAG_MAP_OFFSET);
464 for (i = 0; i < 5; i++) {
465 bit = (tag_map >> (4 * i)) & 0x0f;
466 if (bit < 8)
467 ioatdca->tag_map[i] = bit | DCA_TAG_MAP_VALID;
468 else
469 ioatdca->tag_map[i] = 0;
470 }
471
472 if (!dca2_tag_map_valid(ioatdca->tag_map)) {
473 dev_err(&pdev->dev, "APICID_TAG_MAP set incorrectly by BIOS, "
474 "disabling DCA\n");
475 free_dca_provider(dca);
476 return NULL;
477 }
478
479 err = register_dca_provider(dca, &pdev->dev);
480 if (err) {
481 free_dca_provider(dca);
482 return NULL;
483 }
484
485 return dca;
486 }
487
ioat3_dca_add_requester(struct dca_provider * dca,struct device * dev)488 static int ioat3_dca_add_requester(struct dca_provider *dca, struct device *dev)
489 {
490 struct ioat_dca_priv *ioatdca = dca_priv(dca);
491 struct pci_dev *pdev;
492 int i;
493 u16 id;
494 u16 global_req_table;
495
496 /* This implementation only supports PCI-Express */
497 if (dev->bus != &pci_bus_type)
498 return -ENODEV;
499 pdev = to_pci_dev(dev);
500 id = dcaid_from_pcidev(pdev);
501
502 if (ioatdca->requester_count == ioatdca->max_requesters)
503 return -ENODEV;
504
505 for (i = 0; i < ioatdca->max_requesters; i++) {
506 if (ioatdca->req_slots[i].pdev == NULL) {
507 /* found an empty slot */
508 ioatdca->requester_count++;
509 ioatdca->req_slots[i].pdev = pdev;
510 ioatdca->req_slots[i].rid = id;
511 global_req_table =
512 readw(ioatdca->dca_base + IOAT3_DCA_GREQID_OFFSET);
513 writel(id | IOAT_DCA_GREQID_VALID,
514 ioatdca->iobase + global_req_table + (i * 4));
515 return i;
516 }
517 }
518 /* Error, ioatdma->requester_count is out of whack */
519 return -EFAULT;
520 }
521
ioat3_dca_remove_requester(struct dca_provider * dca,struct device * dev)522 static int ioat3_dca_remove_requester(struct dca_provider *dca,
523 struct device *dev)
524 {
525 struct ioat_dca_priv *ioatdca = dca_priv(dca);
526 struct pci_dev *pdev;
527 int i;
528 u16 global_req_table;
529
530 /* This implementation only supports PCI-Express */
531 if (dev->bus != &pci_bus_type)
532 return -ENODEV;
533 pdev = to_pci_dev(dev);
534
535 for (i = 0; i < ioatdca->max_requesters; i++) {
536 if (ioatdca->req_slots[i].pdev == pdev) {
537 global_req_table =
538 readw(ioatdca->dca_base + IOAT3_DCA_GREQID_OFFSET);
539 writel(0, ioatdca->iobase + global_req_table + (i * 4));
540 ioatdca->req_slots[i].pdev = NULL;
541 ioatdca->req_slots[i].rid = 0;
542 ioatdca->requester_count--;
543 return i;
544 }
545 }
546 return -ENODEV;
547 }
548
ioat3_dca_get_tag(struct dca_provider * dca,struct device * dev,int cpu)549 static u8 ioat3_dca_get_tag(struct dca_provider *dca,
550 struct device *dev,
551 int cpu)
552 {
553 u8 tag;
554
555 struct ioat_dca_priv *ioatdca = dca_priv(dca);
556 int i, apic_id, bit, value;
557 u8 entry;
558
559 tag = 0;
560 apic_id = cpu_physical_id(cpu);
561
562 for (i = 0; i < IOAT_TAG_MAP_LEN; i++) {
563 entry = ioatdca->tag_map[i];
564 if (entry & DCA3_TAG_MAP_BIT_TO_SEL) {
565 bit = entry &
566 ~(DCA3_TAG_MAP_BIT_TO_SEL | DCA3_TAG_MAP_BIT_TO_INV);
567 value = (apic_id & (1 << bit)) ? 1 : 0;
568 } else if (entry & DCA3_TAG_MAP_BIT_TO_INV) {
569 bit = entry & ~DCA3_TAG_MAP_BIT_TO_INV;
570 value = (apic_id & (1 << bit)) ? 0 : 1;
571 } else {
572 value = (entry & DCA3_TAG_MAP_LITERAL_VAL) ? 1 : 0;
573 }
574 tag |= (value << i);
575 }
576
577 return tag;
578 }
579
580 static struct dca_ops ioat3_dca_ops = {
581 .add_requester = ioat3_dca_add_requester,
582 .remove_requester = ioat3_dca_remove_requester,
583 .get_tag = ioat3_dca_get_tag,
584 .dev_managed = ioat_dca_dev_managed,
585 };
586
ioat3_dca_count_dca_slots(void * iobase,u16 dca_offset)587 static int ioat3_dca_count_dca_slots(void *iobase, u16 dca_offset)
588 {
589 int slots = 0;
590 u32 req;
591 u16 global_req_table;
592
593 global_req_table = readw(iobase + dca_offset + IOAT3_DCA_GREQID_OFFSET);
594 if (global_req_table == 0)
595 return 0;
596
597 do {
598 req = readl(iobase + global_req_table + (slots * sizeof(u32)));
599 slots++;
600 } while ((req & IOAT_DCA_GREQID_LASTID) == 0);
601
602 return slots;
603 }
604
ioat3_dca_init(struct pci_dev * pdev,void __iomem * iobase)605 struct dca_provider *ioat3_dca_init(struct pci_dev *pdev, void __iomem *iobase)
606 {
607 struct dca_provider *dca;
608 struct ioat_dca_priv *ioatdca;
609 int slots;
610 int i;
611 int err;
612 u16 dca_offset;
613 u16 csi_fsb_control;
614 u16 pcie_control;
615 u8 bit;
616
617 union {
618 u64 full;
619 struct {
620 u32 low;
621 u32 high;
622 };
623 } tag_map;
624
625 if (!system_has_dca_enabled(pdev))
626 return NULL;
627
628 dca_offset = readw(iobase + IOAT_DCAOFFSET_OFFSET);
629 if (dca_offset == 0)
630 return NULL;
631
632 slots = ioat3_dca_count_dca_slots(iobase, dca_offset);
633 if (slots == 0)
634 return NULL;
635
636 dca = alloc_dca_provider(&ioat3_dca_ops,
637 sizeof(*ioatdca)
638 + (sizeof(struct ioat_dca_slot) * slots));
639 if (!dca)
640 return NULL;
641
642 ioatdca = dca_priv(dca);
643 ioatdca->iobase = iobase;
644 ioatdca->dca_base = iobase + dca_offset;
645 ioatdca->max_requesters = slots;
646
647 /* some bios might not know to turn these on */
648 csi_fsb_control = readw(ioatdca->dca_base + IOAT3_CSI_CONTROL_OFFSET);
649 if ((csi_fsb_control & IOAT3_CSI_CONTROL_PREFETCH) == 0) {
650 csi_fsb_control |= IOAT3_CSI_CONTROL_PREFETCH;
651 writew(csi_fsb_control,
652 ioatdca->dca_base + IOAT3_CSI_CONTROL_OFFSET);
653 }
654 pcie_control = readw(ioatdca->dca_base + IOAT3_PCI_CONTROL_OFFSET);
655 if ((pcie_control & IOAT3_PCI_CONTROL_MEMWR) == 0) {
656 pcie_control |= IOAT3_PCI_CONTROL_MEMWR;
657 writew(pcie_control,
658 ioatdca->dca_base + IOAT3_PCI_CONTROL_OFFSET);
659 }
660
661
662 /* TODO version, compatibility and configuration checks */
663
664 /* copy out the APIC to DCA tag map */
665 tag_map.low =
666 readl(ioatdca->dca_base + IOAT3_APICID_TAG_MAP_OFFSET_LOW);
667 tag_map.high =
668 readl(ioatdca->dca_base + IOAT3_APICID_TAG_MAP_OFFSET_HIGH);
669 for (i = 0; i < 8; i++) {
670 bit = tag_map.full >> (8 * i);
671 ioatdca->tag_map[i] = bit & DCA_TAG_MAP_MASK;
672 }
673
674 err = register_dca_provider(dca, &pdev->dev);
675 if (err) {
676 free_dca_provider(dca);
677 return NULL;
678 }
679
680 return dca;
681 }
682