drivers/dma/ioat_dma.c

   1 /*
   2  * Intel I/OAT DMA Linux driver
   3  * Copyright(c) 2004 - 2007 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 /*
  24  * This driver supports an Intel I/OAT DMA engine, which does asynchronous
  25  * copy operations.
  26  */
  27
  28 #include <linux/init.h>
  29 #include <linux/module.h>
  30 #include <linux/pci.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/dmaengine.h>
  33 #include <linux/delay.h>
  34 #include <linux/dma-mapping.h>
  35 #include <linux/workqueue.h>
  36 #include <linux/i7300_idle.h>
  37 #include "ioatdma.h"
  38 #include "ioatdma_registers.h"
  39 #include "ioatdma_hw.h"
  40
  41 #define to_ioat_chan(chan) container_of(chan, struct ioat_dma_chan, common)
  42 #define to_ioatdma_device(dev) container_of(dev, struct ioatdma_device, common)
  43 #define to_ioat_desc(lh) container_of(lh, struct ioat_desc_sw, node)
  44 #define tx_to_ioat_desc(tx) container_of(tx, struct ioat_desc_sw, async_tx)
  45
  46 #define chan_num(ch) ((int)((ch)->reg_base - (ch)->device->reg_base) / 0x80)
  47 static int ioat_pending_level = 4;
  48 module_param(ioat_pending_level, int, 0644);
  49 MODULE_PARM_DESC(ioat_pending_level,
  50                  "high-water mark for pushing ioat descriptors (default: 4)");
  51
  52 #define RESET_DELAY  msecs_to_jiffies(100)
  53 #define WATCHDOG_DELAY  round_jiffies(msecs_to_jiffies(2000))
  54 static void ioat_dma_chan_reset_part2(struct work_struct *work);
  55 static void ioat_dma_chan_watchdog(struct work_struct *work);
  56
  57 /*
  58  * workaround for IOAT ver.3.0 null descriptor issue
  59  * (channel returns error when size is 0)
  60  */
  61 #define NULL_DESC_BUFFER_SIZE 1
  62
  63 /* internal functions */
  64 static void ioat_dma_start_null_desc(struct ioat_dma_chan *ioat_chan);
  65 static void ioat_dma_memcpy_cleanup(struct ioat_dma_chan *ioat_chan);
  66
  67 static struct ioat_desc_sw *
  68 ioat1_dma_get_next_descriptor(struct ioat_dma_chan *ioat_chan);
  69 static struct ioat_desc_sw *
  70 ioat2_dma_get_next_descriptor(struct ioat_dma_chan *ioat_chan);
  71
  72 static inline struct ioat_dma_chan *ioat_lookup_chan_by_index(
  73                                                 struct ioatdma_device *device,
  74                                                 int index)
  75 {
  76         return device->idx[index];
  77 }
  78
  79 /**
  80  * ioat_dma_do_interrupt - handler used for single vector interrupt mode
  81  * @irq: interrupt id
  82  * @data: interrupt data
  83  */
  84 static irqreturn_t ioat_dma_do_interrupt(int irq, void *data)
  85 {
  86         struct ioatdma_device *instance = data;
  87         struct ioat_dma_chan *ioat_chan;
  88         unsigned long attnstatus;
  89         int bit;
  90         u8 intrctrl;
  91
  92         intrctrl = readb(instance->reg_base + IOAT_INTRCTRL_OFFSET);
  93
  94         if (!(intrctrl & IOAT_INTRCTRL_MASTER_INT_EN))
  95                 return IRQ_NONE;
  96
  97         if (!(intrctrl & IOAT_INTRCTRL_INT_STATUS)) {
  98                 writeb(intrctrl, instance->reg_base + IOAT_INTRCTRL_OFFSET);
  99                 return IRQ_NONE;
 100         }
 101
 102         attnstatus = readl(instance->reg_base + IOAT_ATTNSTATUS_OFFSET);
 103         for_each_bit(bit, &attnstatus, BITS_PER_LONG) {
 104                 ioat_chan = ioat_lookup_chan_by_index(instance, bit);
 105                 tasklet_schedule(&ioat_chan->cleanup_task);
 106         }
 107
 108         writeb(intrctrl, instance->reg_base + IOAT_INTRCTRL_OFFSET);
 109         return IRQ_HANDLED;
 110 }
 111
 112 /**
 113  * ioat_dma_do_interrupt_msix - handler used for vector-per-channel interrupt mode
 114  * @irq: interrupt id
 115  * @data: interrupt data
 116  */
 117 static irqreturn_t ioat_dma_do_interrupt_msix(int irq, void *data)
 118 {
 119         struct ioat_dma_chan *ioat_chan = data;
 120
 121         tasklet_schedule(&ioat_chan->cleanup_task);
 122
 123         return IRQ_HANDLED;
 124 }
 125
 126 static void ioat_dma_cleanup_tasklet(unsigned long data);
 127
 128 /**
 129  * ioat_dma_enumerate_channels - find and initialize the device's channels
 130  * @device: the device to be enumerated
 131  */
 132 static int ioat_dma_enumerate_channels(struct ioatdma_device *device)
 133 {
 134         u8 xfercap_scale;
 135         u32 xfercap;
 136         int i;
 137         struct ioat_dma_chan *ioat_chan;
 138
 139         /*
 140          * IOAT ver.3 workarounds
 141          */
 142         if (device->version == IOAT_VER_3_0) {
 143                 u32 chan_err_mask;
 144                 u16 dev_id;
 145                 u32 dmauncerrsts;
 146
 147                 /*
 148                  * Write CHANERRMSK_INT with 3E07h to mask out the errors
 149                  * that can cause stability issues for IOAT ver.3
 150                  */
 151                 chan_err_mask = 0x3E07;
 152                 pci_write_config_dword(device->pdev,
 153                         IOAT_PCI_CHANERRMASK_INT_OFFSET,
 154                         chan_err_mask);
 155
 156                 /*
 157                  * Clear DMAUNCERRSTS Cfg-Reg Parity Error status bit
 158                  * (workaround for spurious config parity error after restart)
 159                  */
 160                 pci_read_config_word(device->pdev,
 161                         IOAT_PCI_DEVICE_ID_OFFSET,
 162                         &dev_id);
 163                 if (dev_id == PCI_DEVICE_ID_INTEL_IOAT_TBG0) {
 164                         dmauncerrsts = 0x10;
 165                         pci_write_config_dword(device->pdev,
 166                                 IOAT_PCI_DMAUNCERRSTS_OFFSET,
 167                                 dmauncerrsts);
 168                 }
 169         }
 170
 171         device->common.chancnt = readb(device->reg_base + IOAT_CHANCNT_OFFSET);
 172         xfercap_scale = readb(device->reg_base + IOAT_XFERCAP_OFFSET);
 173         xfercap = (xfercap_scale == 0 ? -1 : (1UL << xfercap_scale));
 174
 175 #ifdef  CONFIG_I7300_IDLE_IOAT_CHANNEL
 176         if (i7300_idle_platform_probe(NULL, NULL) == 0) {
 177                 device->common.chancnt--;
 178         }
 179 #endif
 180         for (i = 0; i < device->common.chancnt; i++) {
 181                 ioat_chan = kzalloc(sizeof(*ioat_chan), GFP_KERNEL);
 182                 if (!ioat_chan) {
 183                         device->common.chancnt = i;
 184                         break;
 185                 }
 186
 187                 ioat_chan->device = device;
 188                 ioat_chan->reg_base = device->reg_base + (0x80 * (i + 1));
 189                 ioat_chan->xfercap = xfercap;
 190                 ioat_chan->desccount = 0;
 191                 INIT_DELAYED_WORK(&ioat_chan->work, ioat_dma_chan_reset_part2);
 192                 if (ioat_chan->device->version != IOAT_VER_1_2) {
 193                         writel(IOAT_DCACTRL_CMPL_WRITE_ENABLE
 194                                         | IOAT_DMA_DCA_ANY_CPU,
 195                                 ioat_chan->reg_base + IOAT_DCACTRL_OFFSET);
 196                 }
 197                 spin_lock_init(&ioat_chan->cleanup_lock);
 198                 spin_lock_init(&ioat_chan->desc_lock);
 199                 INIT_LIST_HEAD(&ioat_chan->free_desc);
 200                 INIT_LIST_HEAD(&ioat_chan->used_desc);
 201                 /* This should be made common somewhere in dmaengine.c */
 202                 ioat_chan->common.device = &device->common;
 203                 list_add_tail(&ioat_chan->common.device_node,
 204                               &device->common.channels);
 205                 device->idx[i] = ioat_chan;
 206                 tasklet_init(&ioat_chan->cleanup_task,
 207                              ioat_dma_cleanup_tasklet,
 208                              (unsigned long) ioat_chan);
 209                 tasklet_disable(&ioat_chan->cleanup_task);
 210         }
 211         return device->common.chancnt;
 212 }
 213
 214 /**
 215  * ioat_dma_memcpy_issue_pending - push potentially unrecognized appended
 216  *                                 descriptors to hw
 217  * @chan: DMA channel handle
 218  */
 219 static inline void __ioat1_dma_memcpy_issue_pending(
 220                                                 struct ioat_dma_chan *ioat_chan)
 221 {
 222         ioat_chan->pending = 0;
 223         writeb(IOAT_CHANCMD_APPEND, ioat_chan->reg_base + IOAT1_CHANCMD_OFFSET);
 224 }
 225
 226 static void ioat1_dma_memcpy_issue_pending(struct dma_chan *chan)
 227 {
 228         struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
 229
 230         if (ioat_chan->pending > 0) {
 231                 spin_lock_bh(&ioat_chan->desc_lock);
 232                 __ioat1_dma_memcpy_issue_pending(ioat_chan);
 233                 spin_unlock_bh(&ioat_chan->desc_lock);
 234         }
 235 }
 236
 237 static inline void __ioat2_dma_memcpy_issue_pending(
 238                                                 struct ioat_dma_chan *ioat_chan)
 239 {
 240         ioat_chan->pending = 0;
 241         writew(ioat_chan->dmacount,
 242                ioat_chan->reg_base + IOAT_CHAN_DMACOUNT_OFFSET);
 243 }
 244
 245 static void ioat2_dma_memcpy_issue_pending(struct dma_chan *chan)
 246 {
 247         struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
 248
 249         if (ioat_chan->pending > 0) {
 250                 spin_lock_bh(&ioat_chan->desc_lock);
 251                 __ioat2_dma_memcpy_issue_pending(ioat_chan);
 252                 spin_unlock_bh(&ioat_chan->desc_lock);
 253         }
 254 }
 255
 256
 257 /**
 258  * ioat_dma_chan_reset_part2 - reinit the channel after a reset
 259  */
 260 static void ioat_dma_chan_reset_part2(struct work_struct *work)
 261 {
 262         struct ioat_dma_chan *ioat_chan =
 263                 container_of(work, struct ioat_dma_chan, work.work);
 264         struct ioat_desc_sw *desc;
 265
 266         spin_lock_bh(&ioat_chan->cleanup_lock);
 267         spin_lock_bh(&ioat_chan->desc_lock);
 268
 269         ioat_chan->completion_virt->low = 0;
 270         ioat_chan->completion_virt->high = 0;
 271         ioat_chan->pending = 0;
 272
 273         /*
 274          * count the descriptors waiting, and be sure to do it
 275          * right for both the CB1 line and the CB2 ring
 276          */
 277         ioat_chan->dmacount = 0;
 278         if (ioat_chan->used_desc.prev) {
 279                 desc = to_ioat_desc(ioat_chan->used_desc.prev);
 280                 do {
 281                         ioat_chan->dmacount++;
 282                         desc = to_ioat_desc(desc->node.next);
 283                 } while (&desc->node != ioat_chan->used_desc.next);
 284         }
 285
 286         /*
 287          * write the new starting descriptor address
 288          * this puts channel engine into ARMED state
 289          */
 290         desc = to_ioat_desc(ioat_chan->used_desc.prev);
 291         switch (ioat_chan->device->version) {
 292         case IOAT_VER_1_2:
 293                 writel(((u64) desc->async_tx.phys) & 0x00000000FFFFFFFF,
 294                        ioat_chan->reg_base + IOAT1_CHAINADDR_OFFSET_LOW);
 295                 writel(((u64) desc->async_tx.phys) >> 32,
 296                        ioat_chan->reg_base + IOAT1_CHAINADDR_OFFSET_HIGH);
 297
 298                 writeb(IOAT_CHANCMD_START, ioat_chan->reg_base
 299                         + IOAT_CHANCMD_OFFSET(ioat_chan->device->version));
 300                 break;
 301         case IOAT_VER_2_0:
 302                 writel(((u64) desc->async_tx.phys) & 0x00000000FFFFFFFF,
 303                        ioat_chan->reg_base + IOAT2_CHAINADDR_OFFSET_LOW);
 304                 writel(((u64) desc->async_tx.phys) >> 32,
 305                        ioat_chan->reg_base + IOAT2_CHAINADDR_OFFSET_HIGH);
 306
 307                 /* tell the engine to go with what's left to be done */
 308                 writew(ioat_chan->dmacount,
 309                        ioat_chan->reg_base + IOAT_CHAN_DMACOUNT_OFFSET);
 310
 311                 break;
 312         }
 313         dev_err(&ioat_chan->device->pdev->dev,
 314                 "chan%d reset - %d descs waiting, %d total desc\n",
 315                 chan_num(ioat_chan), ioat_chan->dmacount, ioat_chan->desccount);
 316
 317         spin_unlock_bh(&ioat_chan->desc_lock);
 318         spin_unlock_bh(&ioat_chan->cleanup_lock);
 319 }
 320
 321 /**
 322  * ioat_dma_reset_channel - restart a channel
 323  * @ioat_chan: IOAT DMA channel handle
 324  */
 325 static void ioat_dma_reset_channel(struct ioat_dma_chan *ioat_chan)
 326 {
 327         u32 chansts, chanerr;
 328
 329         if (!ioat_chan->used_desc.prev)
 330                 return;
 331
 332         chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
 333         chansts = (ioat_chan->completion_virt->low
 334                                         & IOAT_CHANSTS_DMA_TRANSFER_STATUS);
 335         if (chanerr) {
 336                 dev_err(&ioat_chan->device->pdev->dev,
 337                         "chan%d, CHANSTS = 0x%08x CHANERR = 0x%04x, clearing\n",
 338                         chan_num(ioat_chan), chansts, chanerr);
 339                 writel(chanerr, ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
 340         }
 341
 342         /*
 343          * whack it upside the head with a reset
 344          * and wait for things to settle out.
 345          * force the pending count to a really big negative
 346          * to make sure no one forces an issue_pending
 347          * while we're waiting.
 348          */
 349
 350         spin_lock_bh(&ioat_chan->desc_lock);
 351         ioat_chan->pending = INT_MIN;
 352         writeb(IOAT_CHANCMD_RESET,
 353                ioat_chan->reg_base
 354                + IOAT_CHANCMD_OFFSET(ioat_chan->device->version));
 355         spin_unlock_bh(&ioat_chan->desc_lock);
 356
 357         /* schedule the 2nd half instead of sleeping a long time */
 358         schedule_delayed_work(&ioat_chan->work, RESET_DELAY);
 359 }
 360
 361 /**
 362  * ioat_dma_chan_watchdog - watch for stuck channels
 363  */
 364 static void ioat_dma_chan_watchdog(struct work_struct *work)
 365 {
 366         struct ioatdma_device *device =
 367                 container_of(work, struct ioatdma_device, work.work);
 368         struct ioat_dma_chan *ioat_chan;
 369         int i;
 370
 371         union {
 372                 u64 full;
 373                 struct {
 374                         u32 low;
 375                         u32 high;
 376                 };
 377         } completion_hw;
 378         unsigned long compl_desc_addr_hw;
 379
 380         for (i = 0; i < device->common.chancnt; i++) {
 381                 ioat_chan = ioat_lookup_chan_by_index(device, i);
 382
 383                 if (ioat_chan->device->version == IOAT_VER_1_2
 384                         /* have we started processing anything yet */
 385                     && ioat_chan->last_completion
 386                         /* have we completed any since last watchdog cycle? */
 387                     && (ioat_chan->last_completion ==
 388                                 ioat_chan->watchdog_completion)
 389                         /* has TCP stuck on one cookie since last watchdog? */
 390                     && (ioat_chan->watchdog_tcp_cookie ==
 391                                 ioat_chan->watchdog_last_tcp_cookie)
 392                     && (ioat_chan->watchdog_tcp_cookie !=
 393                                 ioat_chan->completed_cookie)
 394                         /* is there something in the chain to be processed? */
 395                         /* CB1 chain always has at least the last one processed */
 396                     && (ioat_chan->used_desc.prev != ioat_chan->used_desc.next)
 397                     && ioat_chan->pending == 0) {
 398
 399                         /*
 400                          * check CHANSTS register for completed
 401                          * descriptor address.
 402                          * if it is different than completion writeback,
 403                          * it is not zero
 404                          * and it has changed since the last watchdog
 405                          *     we can assume that channel
 406                          *     is still working correctly
 407                          *     and the problem is in completion writeback.
 408                          *     update completion writeback
 409                          *     with actual CHANSTS value
 410                          * else
 411                          *     try resetting the channel
 412                          */
 413
 414                         completion_hw.low = readl(ioat_chan->reg_base +
 415                                 IOAT_CHANSTS_OFFSET_LOW(ioat_chan->device->version));
 416                         completion_hw.high = readl(ioat_chan->reg_base +
 417                                 IOAT_CHANSTS_OFFSET_HIGH(ioat_chan->device->version));
 418 #if (BITS_PER_LONG == 64)
 419                         compl_desc_addr_hw =
 420                                 completion_hw.full
 421                                 & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_ADDR;
 422 #else
 423                         compl_desc_addr_hw =
 424                                 completion_hw.low & IOAT_LOW_COMPLETION_MASK;
 425 #endif
 426
 427                         if ((compl_desc_addr_hw != 0)
 428                            && (compl_desc_addr_hw != ioat_chan->watchdog_completion)
 429                            && (compl_desc_addr_hw != ioat_chan->last_compl_desc_addr_hw)) {
 430                                 ioat_chan->last_compl_desc_addr_hw = compl_desc_addr_hw;
 431                                 ioat_chan->completion_virt->low = completion_hw.low;
 432                                 ioat_chan->completion_virt->high = completion_hw.high;
 433                         } else {
 434                                 ioat_dma_reset_channel(ioat_chan);
 435                                 ioat_chan->watchdog_completion = 0;
 436                                 ioat_chan->last_compl_desc_addr_hw = 0;
 437                         }
 438
 439                 /*
 440                  * for version 2.0 if there are descriptors yet to be processed
 441                  * and the last completed hasn't changed since the last watchdog
 442                  *      if they haven't hit the pending level
 443                  *          issue the pending to push them through
 444                  *      else
 445                  *          try resetting the channel
 446                  */
 447                 } else if (ioat_chan->device->version == IOAT_VER_2_0
 448                     && ioat_chan->used_desc.prev
 449                     && ioat_chan->last_completion
 450                     && ioat_chan->last_completion == ioat_chan->watchdog_completion) {
 451
 452                         if (ioat_chan->pending < ioat_pending_level)
 453                                 ioat2_dma_memcpy_issue_pending(&ioat_chan->common);
 454                         else {
 455                                 ioat_dma_reset_channel(ioat_chan);
 456                                 ioat_chan->watchdog_completion = 0;
 457                         }
 458                 } else {
 459                         ioat_chan->last_compl_desc_addr_hw = 0;
 460                         ioat_chan->watchdog_completion
 461                                         = ioat_chan->last_completion;
 462                 }
 463
 464                 ioat_chan->watchdog_last_tcp_cookie =
 465                         ioat_chan->watchdog_tcp_cookie;
 466         }
 467
 468         schedule_delayed_work(&device->work, WATCHDOG_DELAY);
 469 }
 470
 471 static dma_cookie_t ioat1_tx_submit(struct dma_async_tx_descriptor *tx)
 472 {
 473         struct ioat_dma_chan *ioat_chan = to_ioat_chan(tx->chan);
 474         struct ioat_desc_sw *first = tx_to_ioat_desc(tx);
 475         struct ioat_desc_sw *prev, *new;
 476         struct ioat_dma_descriptor *hw;
 477         dma_cookie_t cookie;
 478         LIST_HEAD(new_chain);
 479         u32 copy;
 480         size_t len;
 481         dma_addr_t src, dst;
 482         unsigned long orig_flags;
 483         unsigned int desc_count = 0;
 484
 485         /* src and dest and len are stored in the initial descriptor */
 486         len = first->len;
 487         src = first->src;
 488         dst = first->dst;
 489         orig_flags = first->async_tx.flags;
 490         new = first;
 491
 492         spin_lock_bh(&ioat_chan->desc_lock);
 493         prev = to_ioat_desc(ioat_chan->used_desc.prev);
 494         prefetch(prev->hw);
 495         do {
 496                 copy = min_t(size_t, len, ioat_chan->xfercap);
 497
 498                 async_tx_ack(&new->async_tx);
 499
 500                 hw = new->hw;
 501                 hw->size = copy;
 502                 hw->ctl = 0;
 503                 hw->src_addr = src;
 504                 hw->dst_addr = dst;
 505                 hw->next = 0;
 506
 507                 /* chain together the physical address list for the HW */
 508                 wmb();
 509                 prev->hw->next = (u64) new->async_tx.phys;
 510
 511                 len -= copy;
 512                 dst += copy;
 513                 src += copy;
 514
 515                 list_add_tail(&new->node, &new_chain);
 516                 desc_count++;
 517                 prev = new;
 518         } while (len && (new = ioat1_dma_get_next_descriptor(ioat_chan)));
 519
 520         if (!new) {
 521                 dev_err(&ioat_chan->device->pdev->dev,
 522                         "tx submit failed\n");
 523                 spin_unlock_bh(&ioat_chan->desc_lock);
 524                 return -ENOMEM;
 525         }
 526
 527         hw->ctl = IOAT_DMA_DESCRIPTOR_CTL_CP_STS;
 528         if (first->async_tx.callback) {
 529                 hw->ctl |= IOAT_DMA_DESCRIPTOR_CTL_INT_GN;
 530                 if (first != new) {
 531                         /* move callback into to last desc */
 532                         new->async_tx.callback = first->async_tx.callback;
 533                         new->async_tx.callback_param
 534                                         = first->async_tx.callback_param;
 535                         first->async_tx.callback = NULL;
 536                         first->async_tx.callback_param = NULL;
 537                 }
 538         }
 539
 540         new->tx_cnt = desc_count;
 541         new->async_tx.flags = orig_flags; /* client is in control of this ack */
 542
 543         /* store the original values for use in later cleanup */
 544         if (new != first) {
 545                 new->src = first->src;
 546                 new->dst = first->dst;
 547                 new->len = first->len;
 548         }
 549
 550         /* cookie incr and addition to used_list must be atomic */
 551         cookie = ioat_chan->common.cookie;
 552         cookie++;
 553         if (cookie < 0)
 554                 cookie = 1;
 555         ioat_chan->common.cookie = new->async_tx.cookie = cookie;
 556
 557         /* write address into NextDescriptor field of last desc in chain */
 558         to_ioat_desc(ioat_chan->used_desc.prev)->hw->next =
 559                                                         first->async_tx.phys;
 560         list_splice_tail(&new_chain, &ioat_chan->used_desc);
 561
 562         ioat_chan->dmacount += desc_count;
 563         ioat_chan->pending += desc_count;
 564         if (ioat_chan->pending >= ioat_pending_level)
 565                 __ioat1_dma_memcpy_issue_pending(ioat_chan);
 566         spin_unlock_bh(&ioat_chan->desc_lock);
 567
 568         return cookie;
 569 }
 570
 571 static dma_cookie_t ioat2_tx_submit(struct dma_async_tx_descriptor *tx)
 572 {
 573         struct ioat_dma_chan *ioat_chan = to_ioat_chan(tx->chan);
 574         struct ioat_desc_sw *first = tx_to_ioat_desc(tx);
 575         struct ioat_desc_sw *new;
 576         struct ioat_dma_descriptor *hw;
 577         dma_cookie_t cookie;
 578         u32 copy;
 579         size_t len;
 580         dma_addr_t src, dst;
 581         unsigned long orig_flags;
 582         unsigned int desc_count = 0;
 583
 584         /* src and dest and len are stored in the initial descriptor */
 585         len = first->len;
 586         src = first->src;
 587         dst = first->dst;
 588         orig_flags = first->async_tx.flags;
 589         new = first;
 590
 591         /*
 592          * ioat_chan->desc_lock is still in force in version 2 path
 593          * it gets unlocked at end of this function
 594          */
 595         do {
 596                 copy = min_t(size_t, len, ioat_chan->xfercap);
 597
 598                 async_tx_ack(&new->async_tx);
 599
 600                 hw = new->hw;
 601                 hw->size = copy;
 602                 hw->ctl = 0;
 603                 hw->src_addr = src;
 604                 hw->dst_addr = dst;
 605
 606                 len -= copy;
 607                 dst += copy;
 608                 src += copy;
 609                 desc_count++;
 610         } while (len && (new = ioat2_dma_get_next_descriptor(ioat_chan)));
 611
 612         if (!new) {
 613                 dev_err(&ioat_chan->device->pdev->dev,
 614                         "tx submit failed\n");
 615                 spin_unlock_bh(&ioat_chan->desc_lock);
 616                 return -ENOMEM;
 617         }
 618
 619         hw->ctl |= IOAT_DMA_DESCRIPTOR_CTL_CP_STS;
 620         if (first->async_tx.callback) {
 621                 hw->ctl |= IOAT_DMA_DESCRIPTOR_CTL_INT_GN;
 622                 if (first != new) {
 623                         /* move callback into to last desc */
 624                         new->async_tx.callback = first->async_tx.callback;
 625                         new->async_tx.callback_param
 626                                         = first->async_tx.callback_param;
 627                         first->async_tx.callback = NULL;
 628                         first->async_tx.callback_param = NULL;
 629                 }
 630         }
 631
 632         new->tx_cnt = desc_count;
 633         new->async_tx.flags = orig_flags; /* client is in control of this ack */
 634
 635         /* store the original values for use in later cleanup */
 636         if (new != first) {
 637                 new->src = first->src;
 638                 new->dst = first->dst;
 639                 new->len = first->len;
 640         }
 641
 642         /* cookie incr and addition to used_list must be atomic */
 643         cookie = ioat_chan->common.cookie;
 644         cookie++;
 645         if (cookie < 0)
 646                 cookie = 1;
 647         ioat_chan->common.cookie = new->async_tx.cookie = cookie;
 648
 649         ioat_chan->dmacount += desc_count;
 650         ioat_chan->pending += desc_count;
 651         if (ioat_chan->pending >= ioat_pending_level)
 652                 __ioat2_dma_memcpy_issue_pending(ioat_chan);
 653         spin_unlock_bh(&ioat_chan->desc_lock);
 654
 655         return cookie;
 656 }
 657
 658 /**
 659  * ioat_dma_alloc_descriptor - allocate and return a sw and hw descriptor pair
 660  * @ioat_chan: the channel supplying the memory pool for the descriptors
 661  * @flags: allocation flags
 662  */
 663 static struct ioat_desc_sw *ioat_dma_alloc_descriptor(
 664                                         struct ioat_dma_chan *ioat_chan,
 665                                         gfp_t flags)
 666 {
 667         struct ioat_dma_descriptor *desc;
 668         struct ioat_desc_sw *desc_sw;
 669         struct ioatdma_device *ioatdma_device;
 670         dma_addr_t phys;
 671
 672         ioatdma_device = to_ioatdma_device(ioat_chan->common.device);
 673         desc = pci_pool_alloc(ioatdma_device->dma_pool, flags, &phys);
 674         if (unlikely(!desc))
 675                 return NULL;
 676
 677         desc_sw = kzalloc(sizeof(*desc_sw), flags);
 678         if (unlikely(!desc_sw)) {
 679                 pci_pool_free(ioatdma_device->dma_pool, desc, phys);
 680                 return NULL;
 681         }
 682
 683         memset(desc, 0, sizeof(*desc));
 684         dma_async_tx_descriptor_init(&desc_sw->async_tx, &ioat_chan->common);
 685         switch (ioat_chan->device->version) {
 686         case IOAT_VER_1_2:
 687                 desc_sw->async_tx.tx_submit = ioat1_tx_submit;
 688                 break;
 689         case IOAT_VER_2_0:
 690         case IOAT_VER_3_0:
 691                 desc_sw->async_tx.tx_submit = ioat2_tx_submit;
 692                 break;
 693         }
 694         INIT_LIST_HEAD(&desc_sw->async_tx.tx_list);
 695
 696         desc_sw->hw = desc;
 697         desc_sw->async_tx.phys = phys;
 698
 699         return desc_sw;
 700 }
 701
 702 static int ioat_initial_desc_count = 256;
 703 module_param(ioat_initial_desc_count, int, 0644);
 704 MODULE_PARM_DESC(ioat_initial_desc_count,
 705                  "initial descriptors per channel (default: 256)");
 706
 707 /**
 708  * ioat2_dma_massage_chan_desc - link the descriptors into a circle
 709  * @ioat_chan: the channel to be massaged
 710  */
 711 static void ioat2_dma_massage_chan_desc(struct ioat_dma_chan *ioat_chan)
 712 {
 713         struct ioat_desc_sw *desc, *_desc;
 714
 715         /* setup used_desc */
 716         ioat_chan->used_desc.next = ioat_chan->free_desc.next;
 717         ioat_chan->used_desc.prev = NULL;
 718
 719         /* pull free_desc out of the circle so that every node is a hw
 720          * descriptor, but leave it pointing to the list
 721          */
 722         ioat_chan->free_desc.prev->next = ioat_chan->free_desc.next;
 723         ioat_chan->free_desc.next->prev = ioat_chan->free_desc.prev;
 724
 725         /* circle link the hw descriptors */
 726         desc = to_ioat_desc(ioat_chan->free_desc.next);
 727         desc->hw->next = to_ioat_desc(desc->node.next)->async_tx.phys;
 728         list_for_each_entry_safe(desc, _desc, ioat_chan->free_desc.next, node) {
 729                 desc->hw->next = to_ioat_desc(desc->node.next)->async_tx.phys;
 730         }
 731 }
 732
 733 /**
 734  * ioat_dma_alloc_chan_resources - returns the number of allocated descriptors
 735  * @chan: the channel to be filled out
 736  */
 737 static int ioat_dma_alloc_chan_resources(struct dma_chan *chan,
 738                                          struct dma_client *client)
 739 {
 740         struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
 741         struct ioat_desc_sw *desc;
 742         u16 chanctrl;
 743         u32 chanerr;
 744         int i;
 745         LIST_HEAD(tmp_list);
 746
 747         /* have we already been set up? */
 748         if (!list_empty(&ioat_chan->free_desc))
 749                 return ioat_chan->desccount;
 750
 751         /* Setup register to interrupt and write completion status on error */
 752         chanctrl = IOAT_CHANCTRL_ERR_INT_EN |
 753                 IOAT_CHANCTRL_ANY_ERR_ABORT_EN |
 754                 IOAT_CHANCTRL_ERR_COMPLETION_EN;
 755         writew(chanctrl, ioat_chan->reg_base + IOAT_CHANCTRL_OFFSET);
 756
 757         chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
 758         if (chanerr) {
 759                 dev_err(&ioat_chan->device->pdev->dev,
 760                         "CHANERR = %x, clearing\n", chanerr);
 761                 writel(chanerr, ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
 762         }
 763
 764         /* Allocate descriptors */
 765         for (i = 0; i < ioat_initial_desc_count; i++) {
 766                 desc = ioat_dma_alloc_descriptor(ioat_chan, GFP_KERNEL);
 767                 if (!desc) {
 768                         dev_err(&ioat_chan->device->pdev->dev,
 769                                 "Only %d initial descriptors\n", i);
 770                         break;
 771                 }
 772                 list_add_tail(&desc->node, &tmp_list);
 773         }
 774         spin_lock_bh(&ioat_chan->desc_lock);
 775         ioat_chan->desccount = i;
 776         list_splice(&tmp_list, &ioat_chan->free_desc);
 777         if (ioat_chan->device->version != IOAT_VER_1_2)
 778                 ioat2_dma_massage_chan_desc(ioat_chan);
 779         spin_unlock_bh(&ioat_chan->desc_lock);
 780
 781         /* allocate a completion writeback area */
 782         /* doing 2 32bit writes to mmio since 1 64b write doesn't work */
 783         ioat_chan->completion_virt =
 784                 pci_pool_alloc(ioat_chan->device->completion_pool,
 785                                GFP_KERNEL,
 786                                &ioat_chan->completion_addr);
 787         memset(ioat_chan->completion_virt, 0,
 788                sizeof(*ioat_chan->completion_virt));
 789         writel(((u64) ioat_chan->completion_addr) & 0x00000000FFFFFFFF,
 790                ioat_chan->reg_base + IOAT_CHANCMP_OFFSET_LOW);
 791         writel(((u64) ioat_chan->completion_addr) >> 32,
 792                ioat_chan->reg_base + IOAT_CHANCMP_OFFSET_HIGH);
 793
 794         tasklet_enable(&ioat_chan->cleanup_task);
 795         ioat_dma_start_null_desc(ioat_chan);  /* give chain to dma device */
 796         return ioat_chan->desccount;
 797 }
 798
 799 /**
 800  * ioat_dma_free_chan_resources - release all the descriptors
 801  * @chan: the channel to be cleaned
 802  */
 803 static void ioat_dma_free_chan_resources(struct dma_chan *chan)
 804 {
 805         struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
 806         struct ioatdma_device *ioatdma_device = to_ioatdma_device(chan->device);
 807         struct ioat_desc_sw *desc, *_desc;
 808         int in_use_descs = 0;
 809
 810         /* Before freeing channel resources first check
 811          * if they have been previously allocated for this channel.
 812          */
 813         if (ioat_chan->desccount == 0)
 814                 return;
 815
 816         tasklet_disable(&ioat_chan->cleanup_task);
 817         ioat_dma_memcpy_cleanup(ioat_chan);
 818
 819         /* Delay 100ms after reset to allow internal DMA logic to quiesce
 820          * before removing DMA descriptor resources.
 821          */
 822         writeb(IOAT_CHANCMD_RESET,
 823                ioat_chan->reg_base
 824                         + IOAT_CHANCMD_OFFSET(ioat_chan->device->version));
 825         mdelay(100);
 826
 827         spin_lock_bh(&ioat_chan->desc_lock);
 828         switch (ioat_chan->device->version) {
 829         case IOAT_VER_1_2:
 830                 list_for_each_entry_safe(desc, _desc,
 831                                          &ioat_chan->used_desc, node) {
 832                         in_use_descs++;
 833                         list_del(&desc->node);
 834                         pci_pool_free(ioatdma_device->dma_pool, desc->hw,
 835                                       desc->async_tx.phys);
 836                         kfree(desc);
 837                 }
 838                 list_for_each_entry_safe(desc, _desc,
 839                                          &ioat_chan->free_desc, node) {
 840                         list_del(&desc->node);
 841                         pci_pool_free(ioatdma_device->dma_pool, desc->hw,
 842                                       desc->async_tx.phys);
 843                         kfree(desc);
 844                 }
 845                 break;
 846         case IOAT_VER_2_0:
 847         case IOAT_VER_3_0:
 848                 list_for_each_entry_safe(desc, _desc,
 849                                          ioat_chan->free_desc.next, node) {
 850                         list_del(&desc->node);
 851                         pci_pool_free(ioatdma_device->dma_pool, desc->hw,
 852                                       desc->async_tx.phys);
 853                         kfree(desc);
 854                 }
 855                 desc = to_ioat_desc(ioat_chan->free_desc.next);
 856                 pci_pool_free(ioatdma_device->dma_pool, desc->hw,
 857                               desc->async_tx.phys);
 858                 kfree(desc);
 859                 INIT_LIST_HEAD(&ioat_chan->free_desc);
 860                 INIT_LIST_HEAD(&ioat_chan->used_desc);
 861                 break;
 862         }
 863         spin_unlock_bh(&ioat_chan->desc_lock);
 864
 865         pci_pool_free(ioatdma_device->completion_pool,
 866                       ioat_chan->completion_virt,
 867                       ioat_chan->completion_addr);
 868
 869         /* one is ok since we left it on there on purpose */
 870         if (in_use_descs > 1)
 871                 dev_err(&ioat_chan->device->pdev->dev,
 872                         "Freeing %d in use descriptors!\n",
 873                         in_use_descs - 1);
 874
 875         ioat_chan->last_completion = ioat_chan->completion_addr = 0;
 876         ioat_chan->pending = 0;
 877         ioat_chan->dmacount = 0;
 878         ioat_chan->desccount = 0;
 879         ioat_chan->watchdog_completion = 0;
 880         ioat_chan->last_compl_desc_addr_hw = 0;
 881         ioat_chan->watchdog_tcp_cookie =
 882                 ioat_chan->watchdog_last_tcp_cookie = 0;
 883 }
 884
 885 /**
 886  * ioat_dma_get_next_descriptor - return the next available descriptor
 887  * @ioat_chan: IOAT DMA channel handle
 888  *
 889  * Gets the next descriptor from the chain, and must be called with the
 890  * channel's desc_lock held.  Allocates more descriptors if the channel
 891  * has run out.
 892  */
 893 static struct ioat_desc_sw *
 894 ioat1_dma_get_next_descriptor(struct ioat_dma_chan *ioat_chan)
 895 {
 896         struct ioat_desc_sw *new;
 897
 898         if (!list_empty(&ioat_chan->free_desc)) {
 899                 new = to_ioat_desc(ioat_chan->free_desc.next);
 900                 list_del(&new->node);
 901         } else {
 902                 /* try to get another desc */
 903                 new = ioat_dma_alloc_descriptor(ioat_chan, GFP_ATOMIC);
 904                 if (!new) {
 905                         dev_err(&ioat_chan->device->pdev->dev,
 906                                 "alloc failed\n");
 907                         return NULL;
 908                 }
 909         }
 910
 911         prefetch(new->hw);
 912         return new;
 913 }
 914
 915 static struct ioat_desc_sw *
 916 ioat2_dma_get_next_descriptor(struct ioat_dma_chan *ioat_chan)
 917 {
 918         struct ioat_desc_sw *new;
 919
 920         /*
 921          * used.prev points to where to start processing
 922          * used.next points to next free descriptor
 923          * if used.prev == NULL, there are none waiting to be processed
 924          * if used.next == used.prev.prev, there is only one free descriptor,
 925          *      and we need to use it to as a noop descriptor before
 926          *      linking in a new set of descriptors, since the device
 927          *      has probably already read the pointer to it
 928          */
 929         if (ioat_chan->used_desc.prev &&
 930             ioat_chan->used_desc.next == ioat_chan->used_desc.prev->prev) {
 931
 932                 struct ioat_desc_sw *desc;
 933                 struct ioat_desc_sw *noop_desc;
 934                 int i;
 935
 936                 /* set up the noop descriptor */
 937                 noop_desc = to_ioat_desc(ioat_chan->used_desc.next);
 938                 /* set size to non-zero value (channel returns error when size is 0) */
 939                 noop_desc->hw->size = NULL_DESC_BUFFER_SIZE;
 940                 noop_desc->hw->ctl = IOAT_DMA_DESCRIPTOR_NUL;
 941                 noop_desc->hw->src_addr = 0;
 942                 noop_desc->hw->dst_addr = 0;
 943
 944                 ioat_chan->used_desc.next = ioat_chan->used_desc.next->next;
 945                 ioat_chan->pending++;
 946                 ioat_chan->dmacount++;
 947
 948                 /* try to get a few more descriptors */
 949                 for (i = 16; i; i--) {
 950                         desc = ioat_dma_alloc_descriptor(ioat_chan, GFP_ATOMIC);
 951                         if (!desc) {
 952                                 dev_err(&ioat_chan->device->pdev->dev,
 953                                         "alloc failed\n");
 954                                 break;
 955                         }
 956                         list_add_tail(&desc->node, ioat_chan->used_desc.next);
 957
 958                         desc->hw->next
 959                                 = to_ioat_desc(desc->node.next)->async_tx.phys;
 960                         to_ioat_desc(desc->node.prev)->hw->next
 961                                 = desc->async_tx.phys;
 962                         ioat_chan->desccount++;
 963                 }
 964
 965                 ioat_chan->used_desc.next = noop_desc->node.next;
 966         }
 967         new = to_ioat_desc(ioat_chan->used_desc.next);
 968         prefetch(new);
 969         ioat_chan->used_desc.next = new->node.next;
 970
 971         if (ioat_chan->used_desc.prev == NULL)
 972                 ioat_chan->used_desc.prev = &new->node;
 973
 974         prefetch(new->hw);
 975         return new;
 976 }
 977
 978 static struct ioat_desc_sw *ioat_dma_get_next_descriptor(
 979                                                 struct ioat_dma_chan *ioat_chan)
 980 {
 981         if (!ioat_chan)
 982                 return NULL;
 983
 984         switch (ioat_chan->device->version) {
 985         case IOAT_VER_1_2:
 986                 return ioat1_dma_get_next_descriptor(ioat_chan);
 987         case IOAT_VER_2_0:
 988         case IOAT_VER_3_0:
 989                 return ioat2_dma_get_next_descriptor(ioat_chan);
 990         }
 991         return NULL;
 992 }
 993
 994 static struct dma_async_tx_descriptor *ioat1_dma_prep_memcpy(
 995                                                 struct dma_chan *chan,
 996                                                 dma_addr_t dma_dest,
 997                                                 dma_addr_t dma_src,
 998                                                 size_t len,
 999                                                 unsigned long flags)
1000 {
1001         struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
1002         struct ioat_desc_sw *new;
1003
1004         spin_lock_bh(&ioat_chan->desc_lock);
1005         new = ioat_dma_get_next_descriptor(ioat_chan);
1006         spin_unlock_bh(&ioat_chan->desc_lock);
1007
1008         if (new) {
1009                 new->len = len;
1010                 new->dst = dma_dest;
1011                 new->src = dma_src;
1012                 new->async_tx.flags = flags;
1013                 return &new->async_tx;
1014         } else {
1015                 dev_err(&ioat_chan->device->pdev->dev,
1016                         "chan%d - get_next_desc failed: %d descs waiting, %d total desc\n",
1017                         chan_num(ioat_chan), ioat_chan->dmacount, ioat_chan->desccount);
1018                 return NULL;
1019         }
1020 }
1021
1022 static struct dma_async_tx_descriptor *ioat2_dma_prep_memcpy(
1023                                                 struct dma_chan *chan,
1024                                                 dma_addr_t dma_dest,
1025                                                 dma_addr_t dma_src,
1026                                                 size_t len,
1027                                                 unsigned long flags)
1028 {
1029         struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
1030         struct ioat_desc_sw *new;
1031
1032         spin_lock_bh(&ioat_chan->desc_lock);
1033         new = ioat2_dma_get_next_descriptor(ioat_chan);
1034
1035         /*
1036          * leave ioat_chan->desc_lock set in ioat 2 path
1037          * it will get unlocked at end of tx_submit
1038          */
1039
1040         if (new) {
1041                 new->len = len;
1042                 new->dst = dma_dest;
1043                 new->src = dma_src;
1044                 new->async_tx.flags = flags;
1045                 return &new->async_tx;
1046         } else {
1047                 spin_unlock_bh(&ioat_chan->desc_lock);
1048                 dev_err(&ioat_chan->device->pdev->dev,
1049                         "chan%d - get_next_desc failed: %d descs waiting, %d total desc\n",
1050                         chan_num(ioat_chan), ioat_chan->dmacount, ioat_chan->desccount);
1051                 return NULL;
1052         }
1053 }
1054
1055 static void ioat_dma_cleanup_tasklet(unsigned long data)
1056 {
1057         struct ioat_dma_chan *chan = (void *)data;
1058         ioat_dma_memcpy_cleanup(chan);
1059         writew(IOAT_CHANCTRL_INT_DISABLE,
1060                chan->reg_base + IOAT_CHANCTRL_OFFSET);
1061 }
1062
1063 static void
1064 ioat_dma_unmap(struct ioat_dma_chan *ioat_chan, struct ioat_desc_sw *desc)
1065 {
1066         /*
1067          * yes we are unmapping both _page and _single
1068          * alloc'd regions with unmap_page. Is this
1069          * *really* that bad?
1070          */
1071         if (!(desc->async_tx.flags & DMA_COMPL_SKIP_DEST_UNMAP))
1072                 pci_unmap_page(ioat_chan->device->pdev,
1073                                 pci_unmap_addr(desc, dst),
1074                                 pci_unmap_len(desc, len),
1075                                 PCI_DMA_FROMDEVICE);
1076
1077         if (!(desc->async_tx.flags & DMA_COMPL_SKIP_SRC_UNMAP))
1078                 pci_unmap_page(ioat_chan->device->pdev,
1079                                 pci_unmap_addr(desc, src),
1080                                 pci_unmap_len(desc, len),
1081                                 PCI_DMA_TODEVICE);
1082 }
1083
1084 /**
1085  * ioat_dma_memcpy_cleanup - cleanup up finished descriptors
1086  * @chan: ioat channel to be cleaned up
1087  */
1088 static void ioat_dma_memcpy_cleanup(struct ioat_dma_chan *ioat_chan)
1089 {
1090         unsigned long phys_complete;
1091         struct ioat_desc_sw *desc, *_desc;
1092         dma_cookie_t cookie = 0;
1093         unsigned long desc_phys;
1094         struct ioat_desc_sw *latest_desc;
1095
1096         prefetch(ioat_chan->completion_virt);
1097
1098         if (!spin_trylock_bh(&ioat_chan->cleanup_lock))
1099                 return;
1100
1101         /* The completion writeback can happen at any time,
1102            so reads by the driver need to be atomic operations
1103            The descriptor physical addresses are limited to 32-bits
1104            when the CPU can only do a 32-bit mov */
1105
1106 #if (BITS_PER_LONG == 64)
1107         phys_complete =
1108                 ioat_chan->completion_virt->full
1109                 & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_ADDR;
1110 #else
1111         phys_complete =
1112                 ioat_chan->completion_virt->low & IOAT_LOW_COMPLETION_MASK;
1113 #endif
1114
1115         if ((ioat_chan->completion_virt->full
1116                 & IOAT_CHANSTS_DMA_TRANSFER_STATUS) ==
1117                                 IOAT_CHANSTS_DMA_TRANSFER_STATUS_HALTED) {
1118                 dev_err(&ioat_chan->device->pdev->dev,
1119                         "Channel halted, chanerr = %x\n",
1120                         readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET));
1121
1122                 /* TODO do something to salvage the situation */
1123         }
1124
1125         if (phys_complete == ioat_chan->last_completion) {
1126                 spin_unlock_bh(&ioat_chan->cleanup_lock);
1127                 /*
1128                  * perhaps we're stuck so hard that the watchdog can't go off?
1129                  * try to catch it after 2 seconds
1130                  */
1131                 if (ioat_chan->device->version != IOAT_VER_3_0) {
1132                         if (time_after(jiffies,
1133                                        ioat_chan->last_completion_time + HZ*WATCHDOG_DELAY)) {
1134                                 ioat_dma_chan_watchdog(&(ioat_chan->device->work.work));
1135                                 ioat_chan->last_completion_time = jiffies;
1136                         }
1137                 }
1138                 return;
1139         }
1140         ioat_chan->last_completion_time = jiffies;
1141
1142         cookie = 0;
1143         if (!spin_trylock_bh(&ioat_chan->desc_lock)) {
1144                 spin_unlock_bh(&ioat_chan->cleanup_lock);
1145                 return;
1146         }
1147
1148         switch (ioat_chan->device->version) {
1149         case IOAT_VER_1_2:
1150                 list_for_each_entry_safe(desc, _desc,
1151                                          &ioat_chan->used_desc, node) {
1152
1153                         /*
1154                          * Incoming DMA requests may use multiple descriptors,
1155                          * due to exceeding xfercap, perhaps. If so, only the
1156                          * last one will have a cookie, and require unmapping.
1157                          */
1158                         if (desc->async_tx.cookie) {
1159                                 cookie = desc->async_tx.cookie;
1160                                 ioat_dma_unmap(ioat_chan, desc);
1161                                 if (desc->async_tx.callback) {
1162                                         desc->async_tx.callback(desc->async_tx.callback_param);
1163                                         desc->async_tx.callback = NULL;
1164                                 }
1165                         }
1166
1167                         if (desc->async_tx.phys != phys_complete) {
1168                                 /*
1169                                  * a completed entry, but not the last, so clean
1170                                  * up if the client is done with the descriptor
1171                                  */
1172                                 if (async_tx_test_ack(&desc->async_tx)) {
1173                                         list_del(&desc->node);
1174                                         list_add_tail(&desc->node,
1175                                                       &ioat_chan->free_desc);
1176                                 } else
1177                                         desc->async_tx.cookie = 0;
1178                         } else {
1179                                 /*
1180                                  * last used desc. Do not remove, so we can
1181                                  * append from it, but don't look at it next
1182                                  * time, either
1183                                  */
1184                                 desc->async_tx.cookie = 0;
1185
1186                                 /* TODO check status bits? */
1187                                 break;
1188                         }
1189                 }
1190                 break;
1191         case IOAT_VER_2_0:
1192         case IOAT_VER_3_0:
1193                 /* has some other thread has already cleaned up? */
1194                 if (ioat_chan->used_desc.prev == NULL)
1195                         break;
1196
1197                 /* work backwards to find latest finished desc */
1198                 desc = to_ioat_desc(ioat_chan->used_desc.next);
1199                 latest_desc = NULL;
1200                 do {
1201                         desc = to_ioat_desc(desc->node.prev);
1202                         desc_phys = (unsigned long)desc->async_tx.phys
1203                                        & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_ADDR;
1204                         if (desc_phys == phys_complete) {
1205                                 latest_desc = desc;
1206                                 break;
1207                         }
1208                 } while (&desc->node != ioat_chan->used_desc.prev);
1209
1210                 if (latest_desc != NULL) {
1211
1212                         /* work forwards to clear finished descriptors */
1213                         for (desc = to_ioat_desc(ioat_chan->used_desc.prev);
1214                              &desc->node != latest_desc->node.next &&
1215                              &desc->node != ioat_chan->used_desc.next;
1216                              desc = to_ioat_desc(desc->node.next)) {
1217                                 if (desc->async_tx.cookie) {
1218                                         cookie = desc->async_tx.cookie;
1219                                         desc->async_tx.cookie = 0;
1220                                         ioat_dma_unmap(ioat_chan, desc);
1221                                         if (desc->async_tx.callback) {
1222                                                 desc->async_tx.callback(desc->async_tx.callback_param);
1223                                                 desc->async_tx.callback = NULL;
1224                                         }
1225                                 }
1226                         }
1227
1228                         /* move used.prev up beyond those that are finished */
1229                         if (&desc->node == ioat_chan->used_desc.next)
1230                                 ioat_chan->used_desc.prev = NULL;
1231                         else
1232                                 ioat_chan->used_desc.prev = &desc->node;
1233                 }
1234                 break;
1235         }
1236
1237         spin_unlock_bh(&ioat_chan->desc_lock);
1238
1239         ioat_chan->last_completion = phys_complete;
1240         if (cookie != 0)
1241                 ioat_chan->completed_cookie = cookie;
1242
1243         spin_unlock_bh(&ioat_chan->cleanup_lock);
1244 }
1245
1246 /**
1247  * ioat_dma_is_complete - poll the status of a IOAT DMA transaction
1248  * @chan: IOAT DMA channel handle
1249  * @cookie: DMA transaction identifier
1250  * @done: if not %NULL, updated with last completed transaction
1251  * @used: if not %NULL, updated with last used transaction
1252  */
1253 static enum dma_status ioat_dma_is_complete(struct dma_chan *chan,
1254                                             dma_cookie_t cookie,
1255                                             dma_cookie_t *done,
1256                                             dma_cookie_t *used)
1257 {
1258         struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
1259         dma_cookie_t last_used;
1260         dma_cookie_t last_complete;
1261         enum dma_status ret;
1262
1263         last_used = chan->cookie;
1264         last_complete = ioat_chan->completed_cookie;
1265         ioat_chan->watchdog_tcp_cookie = cookie;
1266
1267         if (done)
1268                 *done = last_complete;
1269         if (used)
1270                 *used = last_used;
1271
1272         ret = dma_async_is_complete(cookie, last_complete, last_used);
1273         if (ret == DMA_SUCCESS)
1274                 return ret;
1275
1276         ioat_dma_memcpy_cleanup(ioat_chan);
1277
1278         last_used = chan->cookie;
1279         last_complete = ioat_chan->completed_cookie;
1280
1281         if (done)
1282                 *done = last_complete;
1283         if (used)
1284                 *used = last_used;
1285
1286         return dma_async_is_complete(cookie, last_complete, last_used);
1287 }
1288
1289 static void ioat_dma_start_null_desc(struct ioat_dma_chan *ioat_chan)
1290 {
1291         struct ioat_desc_sw *desc;
1292
1293         spin_lock_bh(&ioat_chan->desc_lock);
1294
1295         desc = ioat_dma_get_next_descriptor(ioat_chan);
1296
1297         if (!desc) {
1298                 dev_err(&ioat_chan->device->pdev->dev,
1299                         "Unable to start null desc - get next desc failed\n");
1300                 spin_unlock_bh(&ioat_chan->desc_lock);
1301                 return;
1302         }
1303
1304         desc->hw->ctl = IOAT_DMA_DESCRIPTOR_NUL
1305                                 | IOAT_DMA_DESCRIPTOR_CTL_INT_GN
1306                                 | IOAT_DMA_DESCRIPTOR_CTL_CP_STS;
1307         /* set size to non-zero value (channel returns error when size is 0) */
1308         desc->hw->size = NULL_DESC_BUFFER_SIZE;
1309         desc->hw->src_addr = 0;
1310         desc->hw->dst_addr = 0;
1311         async_tx_ack(&desc->async_tx);
1312         switch (ioat_chan->device->version) {
1313         case IOAT_VER_1_2:
1314                 desc->hw->next = 0;
1315                 list_add_tail(&desc->node, &ioat_chan->used_desc);
1316
1317                 writel(((u64) desc->async_tx.phys) & 0x00000000FFFFFFFF,
1318                        ioat_chan->reg_base + IOAT1_CHAINADDR_OFFSET_LOW);
1319                 writel(((u64) desc->async_tx.phys) >> 32,
1320                        ioat_chan->reg_base + IOAT1_CHAINADDR_OFFSET_HIGH);
1321
1322                 writeb(IOAT_CHANCMD_START, ioat_chan->reg_base
1323                         + IOAT_CHANCMD_OFFSET(ioat_chan->device->version));
1324                 break;
1325         case IOAT_VER_2_0:
1326         case IOAT_VER_3_0:
1327                 writel(((u64) desc->async_tx.phys) & 0x00000000FFFFFFFF,
1328                        ioat_chan->reg_base + IOAT2_CHAINADDR_OFFSET_LOW);
1329                 writel(((u64) desc->async_tx.phys) >> 32,
1330                        ioat_chan->reg_base + IOAT2_CHAINADDR_OFFSET_HIGH);
1331
1332                 ioat_chan->dmacount++;
1333                 __ioat2_dma_memcpy_issue_pending(ioat_chan);
1334                 break;
1335         }
1336         spin_unlock_bh(&ioat_chan->desc_lock);
1337 }
1338
1339 /*
1340  * Perform a IOAT transaction to verify the HW works.
1341  */
1342 #define IOAT_TEST_SIZE 2000
1343
1344 static void ioat_dma_test_callback(void *dma_async_param)
1345 {
1346         printk(KERN_ERR "ioatdma: ioat_dma_test_callback(%p)\n",
1347                 dma_async_param);
1348 }
1349
1350 /**
1351  * ioat_dma_self_test - Perform a IOAT transaction to verify the HW works.
1352  * @device: device to be tested
1353  */
1354 static int ioat_dma_self_test(struct ioatdma_device *device)
1355 {
1356         int i;
1357         u8 *src;
1358         u8 *dest;
1359         struct dma_chan *dma_chan;
1360         struct dma_async_tx_descriptor *tx;
1361         dma_addr_t dma_dest, dma_src;
1362         dma_cookie_t cookie;
1363         int err = 0;
1364
1365         src = kzalloc(sizeof(u8) * IOAT_TEST_SIZE, GFP_KERNEL);
1366         if (!src)
1367                 return -ENOMEM;
1368         dest = kzalloc(sizeof(u8) * IOAT_TEST_SIZE, GFP_KERNEL);
1369         if (!dest) {
1370                 kfree(src);
1371                 return -ENOMEM;
1372         }
1373
1374         /* Fill in src buffer */
1375         for (i = 0; i < IOAT_TEST_SIZE; i++)
1376                 src[i] = (u8)i;
1377
1378         /* Start copy, using first DMA channel */
1379         dma_chan = container_of(device->common.channels.next,
1380                                 struct dma_chan,
1381                                 device_node);
1382         if (device->common.device_alloc_chan_resources(dma_chan, NULL) < 1) {
1383                 dev_err(&device->pdev->dev,
1384                         "selftest cannot allocate chan resource\n");
1385                 err = -ENODEV;
1386                 goto out;
1387         }
1388
1389         dma_src = dma_map_single(dma_chan->device->dev, src, IOAT_TEST_SIZE,
1390                                  DMA_TO_DEVICE);
1391         dma_dest = dma_map_single(dma_chan->device->dev, dest, IOAT_TEST_SIZE,
1392                                   DMA_FROM_DEVICE);
1393         tx = device->common.device_prep_dma_memcpy(dma_chan, dma_dest, dma_src,
1394                                                    IOAT_TEST_SIZE, 0);
1395         if (!tx) {
1396                 dev_err(&device->pdev->dev,
1397                         "Self-test prep failed, disabling\n");
1398                 err = -ENODEV;
1399                 goto free_resources;
1400         }
1401
1402         async_tx_ack(tx);
1403         tx->callback = ioat_dma_test_callback;
1404         tx->callback_param = (void *)0x8086;
1405         cookie = tx->tx_submit(tx);
1406         if (cookie < 0) {
1407                 dev_err(&device->pdev->dev,
1408                         "Self-test setup failed, disabling\n");
1409                 err = -ENODEV;
1410                 goto free_resources;
1411         }
1412         device->common.device_issue_pending(dma_chan);
1413         msleep(1);
1414
1415         if (device->common.device_is_tx_complete(dma_chan, cookie, NULL, NULL)
1416                                         != DMA_SUCCESS) {
1417                 dev_err(&device->pdev->dev,
1418                         "Self-test copy timed out, disabling\n");
1419                 err = -ENODEV;
1420                 goto free_resources;
1421         }
1422         if (memcmp(src, dest, IOAT_TEST_SIZE)) {
1423                 dev_err(&device->pdev->dev,
1424                         "Self-test copy failed compare, disabling\n");
1425                 err = -ENODEV;
1426                 goto free_resources;
1427         }
1428
1429 free_resources:
1430         device->common.device_free_chan_resources(dma_chan);
1431 out:
1432         kfree(src);
1433         kfree(dest);
1434         return err;
1435 }
1436
1437 static char ioat_interrupt_style[32] = "msix";
1438 module_param_string(ioat_interrupt_style, ioat_interrupt_style,
1439                     sizeof(ioat_interrupt_style), 0644);
1440 MODULE_PARM_DESC(ioat_interrupt_style,
1441                  "set ioat interrupt style: msix (default), "
1442                  "msix-single-vector, msi, intx)");
1443
1444 /**
1445  * ioat_dma_setup_interrupts - setup interrupt handler
1446  * @device: ioat device
1447  */
1448 static int ioat_dma_setup_interrupts(struct ioatdma_device *device)
1449 {
1450         struct ioat_dma_chan *ioat_chan;
1451         int err, i, j, msixcnt;
1452         u8 intrctrl = 0;
1453
1454         if (!strcmp(ioat_interrupt_style, "msix"))
1455                 goto msix;
1456         if (!strcmp(ioat_interrupt_style, "msix-single-vector"))
1457                 goto msix_single_vector;
1458         if (!strcmp(ioat_interrupt_style, "msi"))
1459                 goto msi;
1460         if (!strcmp(ioat_interrupt_style, "intx"))
1461                 goto intx;
1462         dev_err(&device->pdev->dev, "invalid ioat_interrupt_style %s\n",
1463                 ioat_interrupt_style);
1464         goto err_no_irq;
1465
1466 msix:
1467         /* The number of MSI-X vectors should equal the number of channels */
1468         msixcnt = device->common.chancnt;
1469         for (i = 0; i < msixcnt; i++)
1470                 device->msix_entries[i].entry = i;
1471
1472         err = pci_enable_msix(device->pdev, device->msix_entries, msixcnt);
1473         if (err < 0)
1474                 goto msi;
1475         if (err > 0)
1476                 goto msix_single_vector;
1477
1478         for (i = 0; i < msixcnt; i++) {
1479                 ioat_chan = ioat_lookup_chan_by_index(device, i);
1480                 err = request_irq(device->msix_entries[i].vector,
1481                                   ioat_dma_do_interrupt_msix,
1482                                   0, "ioat-msix", ioat_chan);
1483                 if (err) {
1484                         for (j = 0; j < i; j++) {
1485                                 ioat_chan =
1486                                         ioat_lookup_chan_by_index(device, j);
1487                                 free_irq(device->msix_entries[j].vector,
1488                                          ioat_chan);
1489                         }
1490                         goto msix_single_vector;
1491                 }
1492         }
1493         intrctrl |= IOAT_INTRCTRL_MSIX_VECTOR_CONTROL;
1494         device->irq_mode = msix_multi_vector;
1495         goto done;
1496
1497 msix_single_vector:
1498         device->msix_entries[0].entry = 0;
1499         err = pci_enable_msix(device->pdev, device->msix_entries, 1);
1500         if (err)
1501                 goto msi;
1502
1503         err = request_irq(device->msix_entries[0].vector, ioat_dma_do_interrupt,
1504                           0, "ioat-msix", device);
1505         if (err) {
1506                 pci_disable_msix(device->pdev);
1507                 goto msi;
1508         }
1509         device->irq_mode = msix_single_vector;
1510         goto done;
1511
1512 msi:
1513         err = pci_enable_msi(device->pdev);
1514         if (err)
1515                 goto intx;
1516
1517         err = request_irq(device->pdev->irq, ioat_dma_do_interrupt,
1518                           0, "ioat-msi", device);
1519         if (err) {
1520                 pci_disable_msi(device->pdev);
1521                 goto intx;
1522         }
1523         /*
1524          * CB 1.2 devices need a bit set in configuration space to enable MSI
1525          */
1526         if (device->version == IOAT_VER_1_2) {
1527                 u32 dmactrl;
1528                 pci_read_config_dword(device->pdev,
1529                                       IOAT_PCI_DMACTRL_OFFSET, &dmactrl);
1530                 dmactrl |= IOAT_PCI_DMACTRL_MSI_EN;
1531                 pci_write_config_dword(device->pdev,
1532                                        IOAT_PCI_DMACTRL_OFFSET, dmactrl);
1533         }
1534         device->irq_mode = msi;
1535         goto done;
1536
1537 intx:
1538         err = request_irq(device->pdev->irq, ioat_dma_do_interrupt,
1539                           IRQF_SHARED, "ioat-intx", device);
1540         if (err)
1541                 goto err_no_irq;
1542         device->irq_mode = intx;
1543
1544 done:
1545         intrctrl |= IOAT_INTRCTRL_MASTER_INT_EN;
1546         writeb(intrctrl, device->reg_base + IOAT_INTRCTRL_OFFSET);
1547         return 0;
1548
1549 err_no_irq:
1550         /* Disable all interrupt generation */
1551         writeb(0, device->reg_base + IOAT_INTRCTRL_OFFSET);
1552         dev_err(&device->pdev->dev, "no usable interrupts\n");
1553         device->irq_mode = none;
1554         return -1;
1555 }
1556
1557 /**
1558  * ioat_dma_remove_interrupts - remove whatever interrupts were set
1559  * @device: ioat device
1560  */
1561 static void ioat_dma_remove_interrupts(struct ioatdma_device *device)
1562 {
1563         struct ioat_dma_chan *ioat_chan;
1564         int i;
1565
1566         /* Disable all interrupt generation */
1567         writeb(0, device->reg_base + IOAT_INTRCTRL_OFFSET);
1568
1569         switch (device->irq_mode) {
1570         case msix_multi_vector:
1571                 for (i = 0; i < device->common.chancnt; i++) {
1572                         ioat_chan = ioat_lookup_chan_by_index(device, i);
1573                         free_irq(device->msix_entries[i].vector, ioat_chan);
1574                 }
1575                 pci_disable_msix(device->pdev);
1576                 break;
1577         case msix_single_vector:
1578                 free_irq(device->msix_entries[0].vector, device);
1579                 pci_disable_msix(device->pdev);
1580                 break;
1581         case msi:
1582                 free_irq(device->pdev->irq, device);
1583                 pci_disable_msi(device->pdev);
1584                 break;
1585         case intx:
1586                 free_irq(device->pdev->irq, device);
1587                 break;
1588         case none:
1589                 dev_warn(&device->pdev->dev,
1590                          "call to %s without interrupts setup\n", __func__);
1591         }
1592         device->irq_mode = none;
1593 }
1594
1595 struct ioatdma_device *ioat_dma_probe(struct pci_dev *pdev,
1596                                       void __iomem *iobase)
1597 {
1598         int err;
1599         struct ioatdma_device *device;
1600
1601         device = kzalloc(sizeof(*device), GFP_KERNEL);
1602         if (!device) {
1603                 err = -ENOMEM;
1604                 goto err_kzalloc;
1605         }
1606         device->pdev = pdev;
1607         device->reg_base = iobase;
1608         device->version = readb(device->reg_base + IOAT_VER_OFFSET);
1609
1610         /* DMA coherent memory pool for DMA descriptor allocations */
1611         device->dma_pool = pci_pool_create("dma_desc_pool", pdev,
1612                                            sizeof(struct ioat_dma_descriptor),
1613                                            64, 0);
1614         if (!device->dma_pool) {
1615                 err = -ENOMEM;
1616                 goto err_dma_pool;
1617         }
1618
1619         device->completion_pool = pci_pool_create("completion_pool", pdev,
1620                                                   sizeof(u64), SMP_CACHE_BYTES,
1621                                                   SMP_CACHE_BYTES);
1622         if (!device->completion_pool) {
1623                 err = -ENOMEM;
1624                 goto err_completion_pool;
1625         }
1626
1627         INIT_LIST_HEAD(&device->common.channels);
1628         ioat_dma_enumerate_channels(device);
1629
1630         device->common.device_alloc_chan_resources =
1631                                                 ioat_dma_alloc_chan_resources;
1632         device->common.device_free_chan_resources =
1633                                                 ioat_dma_free_chan_resources;
1634         device->common.dev = &pdev->dev;
1635
1636         dma_cap_set(DMA_MEMCPY, device->common.cap_mask);
1637         device->common.device_is_tx_complete = ioat_dma_is_complete;
1638         switch (device->version) {
1639         case IOAT_VER_1_2:
1640                 device->common.device_prep_dma_memcpy = ioat1_dma_prep_memcpy;
1641                 device->common.device_issue_pending =
1642                                                 ioat1_dma_memcpy_issue_pending;
1643                 break;
1644         case IOAT_VER_2_0:
1645         case IOAT_VER_3_0:
1646                 device->common.device_prep_dma_memcpy = ioat2_dma_prep_memcpy;
1647                 device->common.device_issue_pending =
1648                                                 ioat2_dma_memcpy_issue_pending;
1649                 break;
1650         }
1651
1652         dev_err(&device->pdev->dev,
1653                 "Intel(R) I/OAT DMA Engine found,"
1654                 " %d channels, device version 0x%02x, driver version %s\n",
1655                 device->common.chancnt, device->version, IOAT_DMA_VERSION);
1656
1657         err = ioat_dma_setup_interrupts(device);
1658         if (err)
1659                 goto err_setup_interrupts;
1660
1661         err = ioat_dma_self_test(device);
1662         if (err)
1663                 goto err_self_test;
1664
1665         ioat_set_tcp_copy_break(device);
1666
1667         dma_async_device_register(&device->common);
1668
1669         if (device->version != IOAT_VER_3_0) {
1670                 INIT_DELAYED_WORK(&device->work, ioat_dma_chan_watchdog);
1671                 schedule_delayed_work(&device->work,
1672                                       WATCHDOG_DELAY);
1673         }
1674
1675         return device;
1676
1677 err_self_test:
1678         ioat_dma_remove_interrupts(device);
1679 err_setup_interrupts:
1680         pci_pool_destroy(device->completion_pool);
1681 err_completion_pool:
1682         pci_pool_destroy(device->dma_pool);
1683 err_dma_pool:
1684         kfree(device);
1685 err_kzalloc:
1686         dev_err(&pdev->dev,
1687                 "Intel(R) I/OAT DMA Engine initialization failed\n");
1688         return NULL;
1689 }
1690
1691 void ioat_dma_remove(struct ioatdma_device *device)
1692 {
1693         struct dma_chan *chan, *_chan;
1694         struct ioat_dma_chan *ioat_chan;
1695
1696         ioat_dma_remove_interrupts(device);
1697
1698         dma_async_device_unregister(&device->common);
1699
1700         pci_pool_destroy(device->dma_pool);
1701         pci_pool_destroy(device->completion_pool);
1702
1703         iounmap(device->reg_base);
1704         pci_release_regions(device->pdev);
1705         pci_disable_device(device->pdev);
1706
1707         if (device->version != IOAT_VER_3_0) {
1708                 cancel_delayed_work(&device->work);
1709         }
1710
1711         list_for_each_entry_safe(chan, _chan,
1712                                  &device->common.channels, device_node) {
1713                 ioat_chan = to_ioat_chan(chan);
1714                 list_del(&chan->device_node);
1715                 kfree(ioat_chan);
1716         }
1717         kfree(device);
1718 }
1719