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 "dma.h"
37 #include "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_dbg(&pdev->dev, "DCA is disabled in BIOS\n");
102
103 return res;
104 }
105
system_has_dca_enabled(struct pci_dev * pdev)106 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_dbg(&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
245 struct dca_provider * __devinit
ioat_dca_init(struct pci_dev * pdev,void __iomem * iobase)246 ioat_dca_init(struct pci_dev *pdev, void __iomem *iobase)
247 {
248 struct dca_provider *dca;
249 struct ioat_dca_priv *ioatdca;
250 u8 *tag_map = NULL;
251 int i;
252 int err;
253 u8 version;
254 u8 max_requesters;
255
256 if (!system_has_dca_enabled(pdev))
257 return NULL;
258
259 /* I/OAT v1 systems must have a known tag_map to support DCA */
260 switch (pdev->vendor) {
261 case PCI_VENDOR_ID_INTEL:
262 switch (pdev->device) {
263 case PCI_DEVICE_ID_INTEL_IOAT:
264 tag_map = ioat_tag_map_BNB;
265 break;
266 case PCI_DEVICE_ID_INTEL_IOAT_CNB:
267 tag_map = ioat_tag_map_CNB;
268 break;
269 case PCI_DEVICE_ID_INTEL_IOAT_SCNB:
270 tag_map = ioat_tag_map_SCNB;
271 break;
272 }
273 break;
274 case PCI_VENDOR_ID_UNISYS:
275 switch (pdev->device) {
276 case PCI_DEVICE_ID_UNISYS_DMA_DIRECTOR:
277 tag_map = ioat_tag_map_UNISYS;
278 break;
279 }
280 break;
281 }
282 if (tag_map == NULL)
283 return NULL;
284
285 version = readb(iobase + IOAT_VER_OFFSET);
286 if (version == IOAT_VER_3_0)
287 max_requesters = IOAT3_DCA_MAX_REQ;
288 else
289 max_requesters = IOAT_DCA_MAX_REQ;
290
291 dca = alloc_dca_provider(&ioat_dca_ops,
292 sizeof(*ioatdca) +
293 (sizeof(struct ioat_dca_slot) * max_requesters));
294 if (!dca)
295 return NULL;
296
297 ioatdca = dca_priv(dca);
298 ioatdca->max_requesters = max_requesters;
299 ioatdca->dca_base = iobase + 0x54;
300
301 /* copy over the APIC ID to DCA tag mapping */
302 for (i = 0; i < IOAT_TAG_MAP_LEN; i++)
303 ioatdca->tag_map[i] = tag_map[i];
304
305 err = register_dca_provider(dca, &pdev->dev);
306 if (err) {
307 free_dca_provider(dca);
308 return NULL;
309 }
310
311 return dca;
312 }
313
314
ioat2_dca_add_requester(struct dca_provider * dca,struct device * dev)315 static int ioat2_dca_add_requester(struct dca_provider *dca, struct device *dev)
316 {
317 struct ioat_dca_priv *ioatdca = dca_priv(dca);
318 struct pci_dev *pdev;
319 int i;
320 u16 id;
321 u16 global_req_table;
322
323 /* This implementation only supports PCI-Express */
324 if (dev->bus != &pci_bus_type)
325 return -ENODEV;
326 pdev = to_pci_dev(dev);
327 id = dcaid_from_pcidev(pdev);
328
329 if (ioatdca->requester_count == ioatdca->max_requesters)
330 return -ENODEV;
331
332 for (i = 0; i < ioatdca->max_requesters; i++) {
333 if (ioatdca->req_slots[i].pdev == NULL) {
334 /* found an empty slot */
335 ioatdca->requester_count++;
336 ioatdca->req_slots[i].pdev = pdev;
337 ioatdca->req_slots[i].rid = id;
338 global_req_table =
339 readw(ioatdca->dca_base + IOAT_DCA_GREQID_OFFSET);
340 writel(id | IOAT_DCA_GREQID_VALID,
341 ioatdca->iobase + global_req_table + (i * 4));
342 return i;
343 }
344 }
345 /* Error, ioatdma->requester_count is out of whack */
346 return -EFAULT;
347 }
348
ioat2_dca_remove_requester(struct dca_provider * dca,struct device * dev)349 static int ioat2_dca_remove_requester(struct dca_provider *dca,
350 struct device *dev)
351 {
352 struct ioat_dca_priv *ioatdca = dca_priv(dca);
353 struct pci_dev *pdev;
354 int i;
355 u16 global_req_table;
356
357 /* This implementation only supports PCI-Express */
358 if (dev->bus != &pci_bus_type)
359 return -ENODEV;
360 pdev = to_pci_dev(dev);
361
362 for (i = 0; i < ioatdca->max_requesters; i++) {
363 if (ioatdca->req_slots[i].pdev == pdev) {
364 global_req_table =
365 readw(ioatdca->dca_base + IOAT_DCA_GREQID_OFFSET);
366 writel(0, ioatdca->iobase + global_req_table + (i * 4));
367 ioatdca->req_slots[i].pdev = NULL;
368 ioatdca->req_slots[i].rid = 0;
369 ioatdca->requester_count--;
370 return i;
371 }
372 }
373 return -ENODEV;
374 }
375
ioat2_dca_get_tag(struct dca_provider * dca,struct device * dev,int cpu)376 static u8 ioat2_dca_get_tag(struct dca_provider *dca,
377 struct device *dev,
378 int cpu)
379 {
380 u8 tag;
381
382 tag = ioat_dca_get_tag(dca, dev, cpu);
383 tag = (~tag) & 0x1F;
384 return tag;
385 }
386
387 static struct dca_ops ioat2_dca_ops = {
388 .add_requester = ioat2_dca_add_requester,
389 .remove_requester = ioat2_dca_remove_requester,
390 .get_tag = ioat2_dca_get_tag,
391 .dev_managed = ioat_dca_dev_managed,
392 };
393
ioat2_dca_count_dca_slots(void __iomem * iobase,u16 dca_offset)394 static int ioat2_dca_count_dca_slots(void __iomem *iobase, u16 dca_offset)
395 {
396 int slots = 0;
397 u32 req;
398 u16 global_req_table;
399
400 global_req_table = readw(iobase + dca_offset + IOAT_DCA_GREQID_OFFSET);
401 if (global_req_table == 0)
402 return 0;
403 do {
404 req = readl(iobase + global_req_table + (slots * sizeof(u32)));
405 slots++;
406 } while ((req & IOAT_DCA_GREQID_LASTID) == 0);
407
408 return slots;
409 }
410
411 struct dca_provider * __devinit
ioat2_dca_init(struct pci_dev * pdev,void __iomem * iobase)412 ioat2_dca_init(struct pci_dev *pdev, void __iomem *iobase)
413 {
414 struct dca_provider *dca;
415 struct ioat_dca_priv *ioatdca;
416 int slots;
417 int i;
418 int err;
419 u32 tag_map;
420 u16 dca_offset;
421 u16 csi_fsb_control;
422 u16 pcie_control;
423 u8 bit;
424
425 if (!system_has_dca_enabled(pdev))
426 return NULL;
427
428 dca_offset = readw(iobase + IOAT_DCAOFFSET_OFFSET);
429 if (dca_offset == 0)
430 return NULL;
431
432 slots = ioat2_dca_count_dca_slots(iobase, dca_offset);
433 if (slots == 0)
434 return NULL;
435
436 dca = alloc_dca_provider(&ioat2_dca_ops,
437 sizeof(*ioatdca)
438 + (sizeof(struct ioat_dca_slot) * slots));
439 if (!dca)
440 return NULL;
441
442 ioatdca = dca_priv(dca);
443 ioatdca->iobase = iobase;
444 ioatdca->dca_base = iobase + dca_offset;
445 ioatdca->max_requesters = slots;
446
447 /* some bios might not know to turn these on */
448 csi_fsb_control = readw(ioatdca->dca_base + IOAT_FSB_CAP_ENABLE_OFFSET);
449 if ((csi_fsb_control & IOAT_FSB_CAP_ENABLE_PREFETCH) == 0) {
450 csi_fsb_control |= IOAT_FSB_CAP_ENABLE_PREFETCH;
451 writew(csi_fsb_control,
452 ioatdca->dca_base + IOAT_FSB_CAP_ENABLE_OFFSET);
453 }
454 pcie_control = readw(ioatdca->dca_base + IOAT_PCI_CAP_ENABLE_OFFSET);
455 if ((pcie_control & IOAT_PCI_CAP_ENABLE_MEMWR) == 0) {
456 pcie_control |= IOAT_PCI_CAP_ENABLE_MEMWR;
457 writew(pcie_control,
458 ioatdca->dca_base + IOAT_PCI_CAP_ENABLE_OFFSET);
459 }
460
461
462 /* TODO version, compatibility and configuration checks */
463
464 /* copy out the APIC to DCA tag map */
465 tag_map = readl(ioatdca->dca_base + IOAT_APICID_TAG_MAP_OFFSET);
466 for (i = 0; i < 5; i++) {
467 bit = (tag_map >> (4 * i)) & 0x0f;
468 if (bit < 8)
469 ioatdca->tag_map[i] = bit | DCA_TAG_MAP_VALID;
470 else
471 ioatdca->tag_map[i] = 0;
472 }
473
474 if (!dca2_tag_map_valid(ioatdca->tag_map)) {
475 dev_err(&pdev->dev, "APICID_TAG_MAP set incorrectly by BIOS, "
476 "disabling DCA\n");
477 free_dca_provider(dca);
478 return NULL;
479 }
480
481 err = register_dca_provider(dca, &pdev->dev);
482 if (err) {
483 free_dca_provider(dca);
484 return NULL;
485 }
486
487 return dca;
488 }
489
ioat3_dca_add_requester(struct dca_provider * dca,struct device * dev)490 static int ioat3_dca_add_requester(struct dca_provider *dca, struct device *dev)
491 {
492 struct ioat_dca_priv *ioatdca = dca_priv(dca);
493 struct pci_dev *pdev;
494 int i;
495 u16 id;
496 u16 global_req_table;
497
498 /* This implementation only supports PCI-Express */
499 if (dev->bus != &pci_bus_type)
500 return -ENODEV;
501 pdev = to_pci_dev(dev);
502 id = dcaid_from_pcidev(pdev);
503
504 if (ioatdca->requester_count == ioatdca->max_requesters)
505 return -ENODEV;
506
507 for (i = 0; i < ioatdca->max_requesters; i++) {
508 if (ioatdca->req_slots[i].pdev == NULL) {
509 /* found an empty slot */
510 ioatdca->requester_count++;
511 ioatdca->req_slots[i].pdev = pdev;
512 ioatdca->req_slots[i].rid = id;
513 global_req_table =
514 readw(ioatdca->dca_base + IOAT3_DCA_GREQID_OFFSET);
515 writel(id | IOAT_DCA_GREQID_VALID,
516 ioatdca->iobase + global_req_table + (i * 4));
517 return i;
518 }
519 }
520 /* Error, ioatdma->requester_count is out of whack */
521 return -EFAULT;
522 }
523
ioat3_dca_remove_requester(struct dca_provider * dca,struct device * dev)524 static int ioat3_dca_remove_requester(struct dca_provider *dca,
525 struct device *dev)
526 {
527 struct ioat_dca_priv *ioatdca = dca_priv(dca);
528 struct pci_dev *pdev;
529 int i;
530 u16 global_req_table;
531
532 /* This implementation only supports PCI-Express */
533 if (dev->bus != &pci_bus_type)
534 return -ENODEV;
535 pdev = to_pci_dev(dev);
536
537 for (i = 0; i < ioatdca->max_requesters; i++) {
538 if (ioatdca->req_slots[i].pdev == pdev) {
539 global_req_table =
540 readw(ioatdca->dca_base + IOAT3_DCA_GREQID_OFFSET);
541 writel(0, ioatdca->iobase + global_req_table + (i * 4));
542 ioatdca->req_slots[i].pdev = NULL;
543 ioatdca->req_slots[i].rid = 0;
544 ioatdca->requester_count--;
545 return i;
546 }
547 }
548 return -ENODEV;
549 }
550
ioat3_dca_get_tag(struct dca_provider * dca,struct device * dev,int cpu)551 static u8 ioat3_dca_get_tag(struct dca_provider *dca,
552 struct device *dev,
553 int cpu)
554 {
555 u8 tag;
556
557 struct ioat_dca_priv *ioatdca = dca_priv(dca);
558 int i, apic_id, bit, value;
559 u8 entry;
560
561 tag = 0;
562 apic_id = cpu_physical_id(cpu);
563
564 for (i = 0; i < IOAT_TAG_MAP_LEN; i++) {
565 entry = ioatdca->tag_map[i];
566 if (entry & DCA3_TAG_MAP_BIT_TO_SEL) {
567 bit = entry &
568 ~(DCA3_TAG_MAP_BIT_TO_SEL | DCA3_TAG_MAP_BIT_TO_INV);
569 value = (apic_id & (1 << bit)) ? 1 : 0;
570 } else if (entry & DCA3_TAG_MAP_BIT_TO_INV) {
571 bit = entry & ~DCA3_TAG_MAP_BIT_TO_INV;
572 value = (apic_id & (1 << bit)) ? 0 : 1;
573 } else {
574 value = (entry & DCA3_TAG_MAP_LITERAL_VAL) ? 1 : 0;
575 }
576 tag |= (value << i);
577 }
578
579 return tag;
580 }
581
582 static struct dca_ops ioat3_dca_ops = {
583 .add_requester = ioat3_dca_add_requester,
584 .remove_requester = ioat3_dca_remove_requester,
585 .get_tag = ioat3_dca_get_tag,
586 .dev_managed = ioat_dca_dev_managed,
587 };
588
ioat3_dca_count_dca_slots(void * iobase,u16 dca_offset)589 static int ioat3_dca_count_dca_slots(void *iobase, u16 dca_offset)
590 {
591 int slots = 0;
592 u32 req;
593 u16 global_req_table;
594
595 global_req_table = readw(iobase + dca_offset + IOAT3_DCA_GREQID_OFFSET);
596 if (global_req_table == 0)
597 return 0;
598
599 do {
600 req = readl(iobase + global_req_table + (slots * sizeof(u32)));
601 slots++;
602 } while ((req & IOAT_DCA_GREQID_LASTID) == 0);
603
604 return slots;
605 }
606
607 struct dca_provider * __devinit
ioat3_dca_init(struct pci_dev * pdev,void __iomem * iobase)608 ioat3_dca_init(struct pci_dev *pdev, void __iomem *iobase)
609 {
610 struct dca_provider *dca;
611 struct ioat_dca_priv *ioatdca;
612 int slots;
613 int i;
614 int err;
615 u16 dca_offset;
616 u16 csi_fsb_control;
617 u16 pcie_control;
618 u8 bit;
619
620 union {
621 u64 full;
622 struct {
623 u32 low;
624 u32 high;
625 };
626 } tag_map;
627
628 if (!system_has_dca_enabled(pdev))
629 return NULL;
630
631 dca_offset = readw(iobase + IOAT_DCAOFFSET_OFFSET);
632 if (dca_offset == 0)
633 return NULL;
634
635 slots = ioat3_dca_count_dca_slots(iobase, dca_offset);
636 if (slots == 0)
637 return NULL;
638
639 dca = alloc_dca_provider(&ioat3_dca_ops,
640 sizeof(*ioatdca)
641 + (sizeof(struct ioat_dca_slot) * slots));
642 if (!dca)
643 return NULL;
644
645 ioatdca = dca_priv(dca);
646 ioatdca->iobase = iobase;
647 ioatdca->dca_base = iobase + dca_offset;
648 ioatdca->max_requesters = slots;
649
650 /* some bios might not know to turn these on */
651 csi_fsb_control = readw(ioatdca->dca_base + IOAT3_CSI_CONTROL_OFFSET);
652 if ((csi_fsb_control & IOAT3_CSI_CONTROL_PREFETCH) == 0) {
653 csi_fsb_control |= IOAT3_CSI_CONTROL_PREFETCH;
654 writew(csi_fsb_control,
655 ioatdca->dca_base + IOAT3_CSI_CONTROL_OFFSET);
656 }
657 pcie_control = readw(ioatdca->dca_base + IOAT3_PCI_CONTROL_OFFSET);
658 if ((pcie_control & IOAT3_PCI_CONTROL_MEMWR) == 0) {
659 pcie_control |= IOAT3_PCI_CONTROL_MEMWR;
660 writew(pcie_control,
661 ioatdca->dca_base + IOAT3_PCI_CONTROL_OFFSET);
662 }
663
664
665 /* TODO version, compatibility and configuration checks */
666
667 /* copy out the APIC to DCA tag map */
668 tag_map.low =
669 readl(ioatdca->dca_base + IOAT3_APICID_TAG_MAP_OFFSET_LOW);
670 tag_map.high =
671 readl(ioatdca->dca_base + IOAT3_APICID_TAG_MAP_OFFSET_HIGH);
672 for (i = 0; i < 8; i++) {
673 bit = tag_map.full >> (8 * i);
674 ioatdca->tag_map[i] = bit & DCA_TAG_MAP_MASK;
675 }
676
677 err = register_dca_provider(dca, &pdev->dev);
678 if (err) {
679 free_dca_provider(dca);
680 return NULL;
681 }
682
683 return dca;
684 }
685