LXR linux/drivers/dma/ioat/dca.c

   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#include "dma_v2.h"
  39
  40/*
  41 * Bit 7 of a tag map entry is the "valid" bit, if it is set then bits 0:6
  42 * contain the bit number of the APIC ID to map into the DCA tag.  If the valid
  43 * bit is not set, then the value must be 0 or 1 and defines the bit in the tag.
  44 */
  45#define DCA_TAG_MAP_VALID 0x80
  46
  47#define DCA3_TAG_MAP_BIT_TO_INV 0x80
  48#define DCA3_TAG_MAP_BIT_TO_SEL 0x40
  49#define DCA3_TAG_MAP_LITERAL_VAL 0x1
  50
  51#define DCA_TAG_MAP_MASK 0xDF
  52
  53/* expected tag map bytes for I/OAT ver.2 */
  54#define DCA2_TAG_MAP_BYTE0 0x80
  55#define DCA2_TAG_MAP_BYTE1 0x0
  56#define DCA2_TAG_MAP_BYTE2 0x81
  57#define DCA2_TAG_MAP_BYTE3 0x82
  58#define DCA2_TAG_MAP_BYTE4 0x82
  59
  60/* verify if tag map matches expected values */
  61static inline int dca2_tag_map_valid(u8 *tag_map)
  62{
  63        return ((tag_map[0] == DCA2_TAG_MAP_BYTE0) &&
  64                (tag_map[1] == DCA2_TAG_MAP_BYTE1) &&
  65                (tag_map[2] == DCA2_TAG_MAP_BYTE2) &&
  66                (tag_map[3] == DCA2_TAG_MAP_BYTE3) &&
  67                (tag_map[4] == DCA2_TAG_MAP_BYTE4));
  68}
  69
  70/*
  71 * "Legacy" DCA systems do not implement the DCA register set in the
  72 * I/OAT device.  Software needs direct support for their tag mappings.
  73 */
  74
  75#define APICID_BIT(x)           (DCA_TAG_MAP_VALID | (x))
  76#define IOAT_TAG_MAP_LEN        8
  77
  78static u8 ioat_tag_map_BNB[IOAT_TAG_MAP_LEN] = {
  79        1, APICID_BIT(1), APICID_BIT(2), APICID_BIT(2), };
  80static u8 ioat_tag_map_SCNB[IOAT_TAG_MAP_LEN] = {
  81        1, APICID_BIT(1), APICID_BIT(2), APICID_BIT(2), };
  82static u8 ioat_tag_map_CNB[IOAT_TAG_MAP_LEN] = {
  83        1, APICID_BIT(1), APICID_BIT(3), APICID_BIT(4), APICID_BIT(2), };
  84static u8 ioat_tag_map_UNISYS[IOAT_TAG_MAP_LEN] = { 0 };
  85
  86/* pack PCI B/D/F into a u16 */
  87static inline u16 dcaid_from_pcidev(struct pci_dev *pci)
  88{
  89        return (pci->bus->number << 8) | pci->devfn;
  90}
  91
  92static int dca_enabled_in_bios(struct pci_dev *pdev)
  93{
  94        /* CPUID level 9 returns DCA configuration */
  95        /* Bit 0 indicates DCA enabled by the BIOS */
  96        unsigned long cpuid_level_9;
  97        int res;
  98
  99        cpuid_level_9 = cpuid_eax(9);
 100        res = test_bit(0, &cpuid_level_9);
 101        if (!res)
 102                dev_dbg(&pdev->dev, "DCA is disabled in BIOS\n");
 103
 104        return res;
 105}
 106
 107int system_has_dca_enabled(struct pci_dev *pdev)
 108{
 109        if (boot_cpu_has(X86_FEATURE_DCA))
 110                return dca_enabled_in_bios(pdev);
 111
 112        dev_dbg(&pdev->dev, "boot cpu doesn't have X86_FEATURE_DCA\n");
 113        return 0;
 114}
 115
 116struct ioat_dca_slot {
 117        struct pci_dev *pdev;   /* requester device */
 118        u16 rid;                /* requester id, as used by IOAT */
 119};
 120
 121#define IOAT_DCA_MAX_REQ 6
 122#define IOAT3_DCA_MAX_REQ 2
 123
 124struct ioat_dca_priv {
 125        void __iomem            *iobase;
 126        void __iomem            *dca_base;
 127        int                      max_requesters;
 128        int                      requester_count;
 129        u8                       tag_map[IOAT_TAG_MAP_LEN];
 130        struct ioat_dca_slot     req_slots[0];
 131};
 132
 133/* 5000 series chipset DCA Port Requester ID Table Entry Format
 134 * [15:8]       PCI-Express Bus Number
 135 * [7:3]        PCI-Express Device Number
 136 * [2:0]        PCI-Express Function Number
 137 *
 138 * 5000 series chipset DCA control register format
 139 * [7:1]        Reserved (0)
 140 * [0]          Ignore Function Number
 141 */
 142
 143static int ioat_dca_add_requester(struct dca_provider *dca, struct device *dev)
 144{
 145        struct ioat_dca_priv *ioatdca = dca_priv(dca);
 146        struct pci_dev *pdev;
 147        int i;
 148        u16 id;
 149
 150        /* This implementation only supports PCI-Express */
 151        if (!dev_is_pci(dev))
 152                return -ENODEV;
 153        pdev = to_pci_dev(dev);
 154        id = dcaid_from_pcidev(pdev);
 155
 156        if (ioatdca->requester_count == ioatdca->max_requesters)
 157                return -ENODEV;
 158
 159        for (i = 0; i < ioatdca->max_requesters; i++) {
 160                if (ioatdca->req_slots[i].pdev == NULL) {
 161                        /* found an empty slot */
 162                        ioatdca->requester_count++;
 163                        ioatdca->req_slots[i].pdev = pdev;
 164                        ioatdca->req_slots[i].rid = id;
 165                        writew(id, ioatdca->dca_base + (i * 4));
 166                        /* make sure the ignore function bit is off */
 167                        writeb(0, ioatdca->dca_base + (i * 4) + 2);
 168                        return i;
 169                }
 170        }
 171        /* Error, ioatdma->requester_count is out of whack */
 172        return -EFAULT;
 173}
 174
 175static int ioat_dca_remove_requester(struct dca_provider *dca,
 176                                     struct device *dev)
 177{
 178        struct ioat_dca_priv *ioatdca = dca_priv(dca);
 179        struct pci_dev *pdev;
 180        int i;
 181
 182        /* This implementation only supports PCI-Express */
 183        if (!dev_is_pci(dev))
 184                return -ENODEV;
 185        pdev = to_pci_dev(dev);
 186
 187        for (i = 0; i < ioatdca->max_requesters; i++) {
 188                if (ioatdca->req_slots[i].pdev == pdev) {
 189                        writew(0, ioatdca->dca_base + (i * 4));
 190                        ioatdca->req_slots[i].pdev = NULL;
 191                        ioatdca->req_slots[i].rid = 0;
 192                        ioatdca->requester_count--;
 193                        return i;
 194                }
 195        }
 196        return -ENODEV;
 197}
 198
 199static u8 ioat_dca_get_tag(struct dca_provider *dca,
 200                           struct device *dev,
 201                           int cpu)
 202{
 203        struct ioat_dca_priv *ioatdca = dca_priv(dca);
 204        int i, apic_id, bit, value;
 205        u8 entry, tag;
 206
 207        tag = 0;
 208        apic_id = cpu_physical_id(cpu);
 209
 210        for (i = 0; i < IOAT_TAG_MAP_LEN; i++) {
 211                entry = ioatdca->tag_map[i];
 212                if (entry & DCA_TAG_MAP_VALID) {
 213                        bit = entry & ~DCA_TAG_MAP_VALID;
 214                        value = (apic_id & (1 << bit)) ? 1 : 0;
 215                } else {
 216                        value = entry ? 1 : 0;
 217                }
 218                tag |= (value << i);
 219        }
 220        return tag;
 221}
 222
 223static int ioat_dca_dev_managed(struct dca_provider *dca,
 224                                struct device *dev)
 225{
 226        struct ioat_dca_priv *ioatdca = dca_priv(dca);
 227        struct pci_dev *pdev;
 228        int i;
 229
 230        pdev = to_pci_dev(dev);
 231        for (i = 0; i < ioatdca->max_requesters; i++) {
 232                if (ioatdca->req_slots[i].pdev == pdev)
 233                        return 1;
 234        }
 235        return 0;
 236}
 237
 238static struct dca_ops ioat_dca_ops = {
 239        .add_requester          = ioat_dca_add_requester,
 240        .remove_requester       = ioat_dca_remove_requester,
 241        .get_tag                = ioat_dca_get_tag,
 242        .dev_managed            = ioat_dca_dev_managed,
 243};
 244
 245
 246struct dca_provider *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
 315static 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_is_pci(dev))
 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
 349static 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_is_pci(dev))
 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
 376static 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
 387static 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
 394static 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
 411struct dca_provider *ioat2_dca_init(struct pci_dev *pdev, void __iomem *iobase)
 412{
 413        struct dca_provider *dca;
 414        struct ioat_dca_priv *ioatdca;
 415        int slots;
 416        int i;
 417        int err;
 418        u32 tag_map;
 419        u16 dca_offset;
 420        u16 csi_fsb_control;
 421        u16 pcie_control;
 422        u8 bit;
 423
 424        if (!system_has_dca_enabled(pdev))
 425                return NULL;
 426
 427        dca_offset = readw(iobase + IOAT_DCAOFFSET_OFFSET);
 428        if (dca_offset == 0)
 429                return NULL;
 430
 431        slots = ioat2_dca_count_dca_slots(iobase, dca_offset);
 432        if (slots == 0)
 433                return NULL;
 434
 435        dca = alloc_dca_provider(&ioat2_dca_ops,
 436                                 sizeof(*ioatdca)
 437                                      + (sizeof(struct ioat_dca_slot) * slots));
 438        if (!dca)
 439                return NULL;
 440
 441        ioatdca = dca_priv(dca);
 442        ioatdca->iobase = iobase;
 443        ioatdca->dca_base = iobase + dca_offset;
 444        ioatdca->max_requesters = slots;
 445
 446        /* some bios might not know to turn these on */
 447        csi_fsb_control = readw(ioatdca->dca_base + IOAT_FSB_CAP_ENABLE_OFFSET);
 448        if ((csi_fsb_control & IOAT_FSB_CAP_ENABLE_PREFETCH) == 0) {
 449                csi_fsb_control |= IOAT_FSB_CAP_ENABLE_PREFETCH;
 450                writew(csi_fsb_control,
 451                       ioatdca->dca_base + IOAT_FSB_CAP_ENABLE_OFFSET);
 452        }
 453        pcie_control = readw(ioatdca->dca_base + IOAT_PCI_CAP_ENABLE_OFFSET);
 454        if ((pcie_control & IOAT_PCI_CAP_ENABLE_MEMWR) == 0) {
 455                pcie_control |= IOAT_PCI_CAP_ENABLE_MEMWR;
 456                writew(pcie_control,
 457                       ioatdca->dca_base + IOAT_PCI_CAP_ENABLE_OFFSET);
 458        }
 459
 460
 461        /* TODO version, compatibility and configuration checks */
 462
 463        /* copy out the APIC to DCA tag map */
 464        tag_map = readl(ioatdca->dca_base + IOAT_APICID_TAG_MAP_OFFSET);
 465        for (i = 0; i < 5; i++) {
 466                bit = (tag_map >> (4 * i)) & 0x0f;
 467                if (bit < 8)
 468                        ioatdca->tag_map[i] = bit | DCA_TAG_MAP_VALID;
 469                else
 470                        ioatdca->tag_map[i] = 0;
 471        }
 472
 473        if (!dca2_tag_map_valid(ioatdca->tag_map)) {
 474                WARN_TAINT_ONCE(1, TAINT_FIRMWARE_WORKAROUND,
 475                                "%s %s: APICID_TAG_MAP set incorrectly by BIOS, disabling DCA\n",
 476                                dev_driver_string(&pdev->dev),
 477                                dev_name(&pdev->dev));
 478                free_dca_provider(dca);
 479                return NULL;
 480        }
 481
 482        err = register_dca_provider(dca, &pdev->dev);
 483        if (err) {
 484                free_dca_provider(dca);
 485                return NULL;
 486        }
 487
 488        return dca;
 489}
 490
 491static int ioat3_dca_add_requester(struct dca_provider *dca, struct device *dev)
 492{
 493        struct ioat_dca_priv *ioatdca = dca_priv(dca);
 494        struct pci_dev *pdev;
 495        int i;
 496        u16 id;
 497        u16 global_req_table;
 498
 499        /* This implementation only supports PCI-Express */
 500        if (!dev_is_pci(dev))
 501                return -ENODEV;
 502        pdev = to_pci_dev(dev);
 503        id = dcaid_from_pcidev(pdev);
 504
 505        if (ioatdca->requester_count == ioatdca->max_requesters)
 506                return -ENODEV;
 507
 508        for (i = 0; i < ioatdca->max_requesters; i++) {
 509                if (ioatdca->req_slots[i].pdev == NULL) {
 510                        /* found an empty slot */
 511                        ioatdca->requester_count++;
 512                        ioatdca->req_slots[i].pdev = pdev;
 513                        ioatdca->req_slots[i].rid = id;
 514                        global_req_table =
 515                              readw(ioatdca->dca_base + IOAT3_DCA_GREQID_OFFSET);
 516                        writel(id | IOAT_DCA_GREQID_VALID,
 517                               ioatdca->iobase + global_req_table + (i * 4));
 518                        return i;
 519                }
 520        }
 521        /* Error, ioatdma->requester_count is out of whack */
 522        return -EFAULT;
 523}
 524
 525static int ioat3_dca_remove_requester(struct dca_provider *dca,
 526                                      struct device *dev)
 527{
 528        struct ioat_dca_priv *ioatdca = dca_priv(dca);
 529        struct pci_dev *pdev;
 530        int i;
 531        u16 global_req_table;
 532
 533        /* This implementation only supports PCI-Express */
 534        if (!dev_is_pci(dev))
 535                return -ENODEV;
 536        pdev = to_pci_dev(dev);
 537
 538        for (i = 0; i < ioatdca->max_requesters; i++) {
 539                if (ioatdca->req_slots[i].pdev == pdev) {
 540                        global_req_table =
 541                              readw(ioatdca->dca_base + IOAT3_DCA_GREQID_OFFSET);
 542                        writel(0, ioatdca->iobase + global_req_table + (i * 4));
 543                        ioatdca->req_slots[i].pdev = NULL;
 544                        ioatdca->req_slots[i].rid = 0;
 545                        ioatdca->requester_count--;
 546                        return i;
 547                }
 548        }
 549        return -ENODEV;
 550}
 551
 552static u8 ioat3_dca_get_tag(struct dca_provider *dca,
 553                            struct device *dev,
 554                            int cpu)
 555{
 556        u8 tag;
 557
 558        struct ioat_dca_priv *ioatdca = dca_priv(dca);
 559        int i, apic_id, bit, value;
 560        u8 entry;
 561
 562        tag = 0;
 563        apic_id = cpu_physical_id(cpu);
 564
 565        for (i = 0; i < IOAT_TAG_MAP_LEN; i++) {
 566                entry = ioatdca->tag_map[i];
 567                if (entry & DCA3_TAG_MAP_BIT_TO_SEL) {
 568                        bit = entry &
 569                                ~(DCA3_TAG_MAP_BIT_TO_SEL | DCA3_TAG_MAP_BIT_TO_INV);
 570                        value = (apic_id & (1 << bit)) ? 1 : 0;
 571                } else if (entry & DCA3_TAG_MAP_BIT_TO_INV) {
 572                        bit = entry & ~DCA3_TAG_MAP_BIT_TO_INV;
 573                        value = (apic_id & (1 << bit)) ? 0 : 1;
 574                } else {
 575                        value = (entry & DCA3_TAG_MAP_LITERAL_VAL) ? 1 : 0;
 576                }
 577                tag |= (value << i);
 578        }
 579
 580        return tag;
 581}
 582
 583static struct dca_ops ioat3_dca_ops = {
 584        .add_requester          = ioat3_dca_add_requester,
 585        .remove_requester       = ioat3_dca_remove_requester,
 586        .get_tag                = ioat3_dca_get_tag,
 587        .dev_managed            = ioat_dca_dev_managed,
 588};
 589
 590static int ioat3_dca_count_dca_slots(void *iobase, u16 dca_offset)
 591{
 592        int slots = 0;
 593        u32 req;
 594        u16 global_req_table;
 595
 596        global_req_table = readw(iobase + dca_offset + IOAT3_DCA_GREQID_OFFSET);
 597        if (global_req_table == 0)
 598                return 0;
 599
 600        do {
 601                req = readl(iobase + global_req_table + (slots * sizeof(u32)));
 602                slots++;
 603        } while ((req & IOAT_DCA_GREQID_LASTID) == 0);
 604
 605        return slots;
 606}
 607
 608static inline int dca3_tag_map_invalid(u8 *tag_map)
 609{
 610        /*
 611         * If the tag map is not programmed by the BIOS the default is:
 612         * 0x80 0x80 0x80 0x80 0x80 0x00 0x00 0x00
 613         *
 614         * This an invalid map and will result in only 2 possible tags
 615         * 0x1F and 0x00.  0x00 is an invalid DCA tag so we know that
 616         * this entire definition is invalid.
 617         */
 618        return ((tag_map[0] == DCA_TAG_MAP_VALID) &&
 619                (tag_map[1] == DCA_TAG_MAP_VALID) &&
 620                (tag_map[2] == DCA_TAG_MAP_VALID) &&
 621                (tag_map[3] == DCA_TAG_MAP_VALID) &&
 622                (tag_map[4] == DCA_TAG_MAP_VALID));
 623}
 624
 625struct dca_provider *ioat3_dca_init(struct pci_dev *pdev, void __iomem *iobase)
 626{
 627        struct dca_provider *dca;
 628        struct ioat_dca_priv *ioatdca;
 629        int slots;
 630        int i;
 631        int err;
 632        u16 dca_offset;
 633        u16 csi_fsb_control;
 634        u16 pcie_control;
 635        u8 bit;
 636
 637        union {
 638                u64 full;
 639                struct {
 640                        u32 low;
 641                        u32 high;
 642                };
 643        } tag_map;
 644
 645        if (!system_has_dca_enabled(pdev))
 646                return NULL;
 647
 648        dca_offset = readw(iobase + IOAT_DCAOFFSET_OFFSET);
 649        if (dca_offset == 0)
 650                return NULL;
 651
 652        slots = ioat3_dca_count_dca_slots(iobase, dca_offset);
 653        if (slots == 0)
 654                return NULL;
 655
 656        dca = alloc_dca_provider(&ioat3_dca_ops,
 657                                 sizeof(*ioatdca)
 658                                      + (sizeof(struct ioat_dca_slot) * slots));
 659        if (!dca)
 660                return NULL;
 661
 662        ioatdca = dca_priv(dca);
 663        ioatdca->iobase = iobase;
 664        ioatdca->dca_base = iobase + dca_offset;
 665        ioatdca->max_requesters = slots;
 666
 667        /* some bios might not know to turn these on */
 668        csi_fsb_control = readw(ioatdca->dca_base + IOAT3_CSI_CONTROL_OFFSET);
 669        if ((csi_fsb_control & IOAT3_CSI_CONTROL_PREFETCH) == 0) {
 670                csi_fsb_control |= IOAT3_CSI_CONTROL_PREFETCH;
 671                writew(csi_fsb_control,
 672                       ioatdca->dca_base + IOAT3_CSI_CONTROL_OFFSET);
 673        }
 674        pcie_control = readw(ioatdca->dca_base + IOAT3_PCI_CONTROL_OFFSET);
 675        if ((pcie_control & IOAT3_PCI_CONTROL_MEMWR) == 0) {
 676                pcie_control |= IOAT3_PCI_CONTROL_MEMWR;
 677                writew(pcie_control,
 678                       ioatdca->dca_base + IOAT3_PCI_CONTROL_OFFSET);
 679        }
 680
 681
 682        /* TODO version, compatibility and configuration checks */
 683
 684        /* copy out the APIC to DCA tag map */
 685        tag_map.low =
 686                readl(ioatdca->dca_base + IOAT3_APICID_TAG_MAP_OFFSET_LOW);
 687        tag_map.high =
 688                readl(ioatdca->dca_base + IOAT3_APICID_TAG_MAP_OFFSET_HIGH);
 689        for (i = 0; i < 8; i++) {
 690                bit = tag_map.full >> (8 * i);
 691                ioatdca->tag_map[i] = bit & DCA_TAG_MAP_MASK;
 692        }
 693
 694        if (dca3_tag_map_invalid(ioatdca->tag_map)) {
 695                WARN_TAINT_ONCE(1, TAINT_FIRMWARE_WORKAROUND,
 696                                "%s %s: APICID_TAG_MAP set incorrectly by BIOS, disabling DCA\n",
 697                                dev_driver_string(&pdev->dev),
 698                                dev_name(&pdev->dev));
 699                free_dca_provider(dca);
 700                return NULL;
 701        }
 702
 703        err = register_dca_provider(dca, &pdev->dev);
 704        if (err) {
 705                free_dca_provider(dca);
 706                return NULL;
 707        }
 708
 709        return dca;
 710}
 711