git.oblomov.eu Git - linux-2.6/blob - 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 {
 739         struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
 740         struct ioat_desc_sw *desc;
 741         u16 chanctrl;
 742         u32 chanerr;
 743         int i;
 744         LIST_HEAD(tmp_list);
 745
 746         /* have we already been set up? */
 747         if (!list_empty(&ioat_chan->free_desc))
 748                 return ioat_chan->desccount;
 749
 750         /* Setup register to interrupt and write completion status on error */
 751         chanctrl = IOAT_CHANCTRL_ERR_INT_EN |
 752                 IOAT_CHANCTRL_ANY_ERR_ABORT_EN |
 753                 IOAT_CHANCTRL_ERR_COMPLETION_EN;
 754         writew(chanctrl, ioat_chan->reg_base + IOAT_CHANCTRL_OFFSET);
 755
 756         chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
 757         if (chanerr) {
 758                 dev_err(&ioat_chan->device->pdev->dev,
 759                         "CHANERR = %x, clearing\n", chanerr);
 760                 writel(chanerr, ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
 761         }
 762
 763         /* Allocate descriptors */
 764         for (i = 0; i < ioat_initial_desc_count; i++) {
 765                 desc = ioat_dma_alloc_descriptor(ioat_chan, GFP_KERNEL);
 766                 if (!desc) {
 767                         dev_err(&ioat_chan->device->pdev->dev,
 768                                 "Only %d initial descriptors\n", i);
 769                         break;
 770                 }
 771                 list_add_tail(&desc->node, &tmp_list);
 772         }
 773         spin_lock_bh(&ioat_chan->desc_lock);
 774         ioat_chan->desccount = i;
 775         list_splice(&tmp_list, &ioat_chan->free_desc);
 776         if (ioat_chan->device->version != IOAT_VER_1_2)
 777                 ioat2_dma_massage_chan_desc(ioat_chan);
 778         spin_unlock_bh(&ioat_chan->desc_lock);
 779
 780         /* allocate a completion writeback area */
 781         /* doing 2 32bit writes to mmio since 1 64b write doesn't work */
 782         ioat_chan->completion_virt =
 783                 pci_pool_alloc(ioat_chan->device->completion_pool,
 784                                GFP_KERNEL,
 785                                &ioat_chan->completion_addr);
 786         memset(ioat_chan->completion_virt, 0,
 787                sizeof(*ioat_chan->completion_virt));
 788         writel(((u64) ioat_chan->completion_addr) & 0x00000000FFFFFFFF,
 789                ioat_chan->reg_base + IOAT_CHANCMP_OFFSET_LOW);
 790         writel(((u64) ioat_chan->completion_addr) >> 32,
 791                ioat_chan->reg_base + IOAT_CHANCMP_OFFSET_HIGH);
 792
 793         tasklet_enable(&ioat_chan->cleanup_task);
 794         ioat_dma_start_null_desc(ioat_chan);  /* give chain to dma device */
 795         return ioat_chan->desccount;
 796 }
 797
 798 /**
 799  * ioat_dma_free_chan_resources - release all the descriptors
 800  * @chan: the channel to be cleaned
 801  */
 802 static void ioat_dma_free_chan_resources(struct dma_chan *chan)
 803 {
 804         struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
 805         struct ioatdma_device *ioatdma_device = to_ioatdma_device(chan->device);
 806         struct ioat_desc_sw *desc, *_desc;
 807         int in_use_descs = 0;
 808
 809         /* Before freeing channel resources first check
 810          * if they have been previously allocated for this channel.
 811          */
 812         if (ioat_chan->desccount == 0)
 813                 return;
 814
 815         tasklet_disable(&ioat_chan->cleanup_task);
 816         ioat_dma_memcpy_cleanup(ioat_chan);
 817
 818         /* Delay 100ms after reset to allow internal DMA logic to quiesce
 819          * before removing DMA descriptor resources.
 820          */
 821         writeb(IOAT_CHANCMD_RESET,
 822                ioat_chan->reg_base
 823                         + IOAT_CHANCMD_OFFSET(ioat_chan->device->version));
 824         mdelay(100);
 825
 826         spin_lock_bh(&ioat_chan->desc_lock);
 827         switch (ioat_chan->device->version) {
 828         case IOAT_VER_1_2:
 829                 list_for_each_entry_safe(desc, _desc,
 830                                          &ioat_chan->used_desc, node) {
 831                         in_use_descs++;
 832                         list_del(&desc->node);
 833                         pci_pool_free(ioatdma_device->dma_pool, desc->hw,
 834                                       desc->async_tx.phys);
 835                         kfree(desc);
 836                 }
 837                 list_for_each_entry_safe(desc, _desc,
 838                                          &ioat_chan->free_desc, node) {
 839                         list_del(&desc->node);
 840                         pci_pool_free(ioatdma_device->dma_pool, desc->hw,
 841                                       desc->async_tx.phys);
 842                         kfree(desc);
 843                 }
 844                 break;
 845         case IOAT_VER_2_0:
 846         case IOAT_VER_3_0:
 847                 list_for_each_entry_safe(desc, _desc,
 848                                          ioat_chan->free_desc.next, node) {
 849                         list_del(&desc->node);
 850                         pci_pool_free(ioatdma_device->dma_pool, desc->hw,
 851                                       desc->async_tx.phys);
 852                         kfree(desc);
 853                 }
 854                 desc = to_ioat_desc(ioat_chan->free_desc.next);
 855                 pci_pool_free(ioatdma_device->dma_pool, desc->hw,
 856                               desc->async_tx.phys);
 857                 kfree(desc);
 858                 INIT_LIST_HEAD(&ioat_chan->free_desc);
 859                 INIT_LIST_HEAD(&ioat_chan->used_desc);
 860                 break;
 861         }
 862         spin_unlock_bh(&ioat_chan->desc_lock);
 863
 864         pci_pool_free(ioatdma_device->completion_pool,
 865                       ioat_chan->completion_virt,
 866                       ioat_chan->completion_addr);
 867
 868         /* one is ok since we left it on there on purpose */
 869         if (in_use_descs > 1)
 870                 dev_err(&ioat_chan->device->pdev->dev,
 871                         "Freeing %d in use descriptors!\n",
 872                         in_use_descs - 1);
 873
 874         ioat_chan->last_completion = ioat_chan->completion_addr = 0;
 875         ioat_chan->pending = 0;
 876         ioat_chan->dmacount = 0;
 877         ioat_chan->desccount = 0;
 878         ioat_chan->watchdog_completion = 0;
 879         ioat_chan->last_compl_desc_addr_hw = 0;
 880         ioat_chan->watchdog_tcp_cookie =
 881                 ioat_chan->watchdog_last_tcp_cookie = 0;
 882 }
 883
 884 /**
 885  * ioat_dma_get_next_descriptor - return the next available descriptor
 886  * @ioat_chan: IOAT DMA channel handle
 887  *
 888  * Gets the next descriptor from the chain, and must be called with the
 889  * channel's desc_lock held.  Allocates more descriptors if the channel
 890  * has run out.
 891  */
 892 static struct ioat_desc_sw *
 893 ioat1_dma_get_next_descriptor(struct ioat_dma_chan *ioat_chan)
 894 {
 895         struct ioat_desc_sw *new;
 896
 897         if (!list_empty(&ioat_chan->free_desc)) {
 898                 new = to_ioat_desc(ioat_chan->free_desc.next);
 899                 list_del(&new->node);
 900         } else {
 901                 /* try to get another desc */
 902                 new = ioat_dma_alloc_descriptor(ioat_chan, GFP_ATOMIC);
 903                 if (!new) {
 904                         dev_err(&ioat_chan->device->pdev->dev,
 905                                 "alloc failed\n");
 906                         return NULL;
 907                 }
 908         }
 909
 910         prefetch(new->hw);
 911         return new;
 912 }
 913
 914 static struct ioat_desc_sw *
 915 ioat2_dma_get_next_descriptor(struct ioat_dma_chan *ioat_chan)
 916 {
 917         struct ioat_desc_sw *new;
 918
 919         /*
 920          * used.prev points to where to start processing
 921          * used.next points to next free descriptor
 922          * if used.prev == NULL, there are none waiting to be processed
 923          * if used.next == used.prev.prev, there is only one free descriptor,
 924          *      and we need to use it to as a noop descriptor before
 925          *      linking in a new set of descriptors, since the device
 926          *      has probably already read the pointer to it
 927          */
 928         if (ioat_chan->used_desc.prev &&
 929             ioat_chan->used_desc.next == ioat_chan->used_desc.prev->prev) {
 930
 931                 struct ioat_desc_sw *desc;
 932                 struct ioat_desc_sw *noop_desc;
 933                 int i;
 934
 935                 /* set up the noop descriptor */
 936                 noop_desc = to_ioat_desc(ioat_chan->used_desc.next);
 937                 /* set size to non-zero value (channel returns error when size is 0) */
 938                 noop_desc->hw->size = NULL_DESC_BUFFER_SIZE;
 939                 noop_desc->hw->ctl = IOAT_DMA_DESCRIPTOR_NUL;
 940                 noop_desc->hw->src_addr = 0;
 941                 noop_desc->hw->dst_addr = 0;
 942
 943                 ioat_chan->used_desc.next = ioat_chan->used_desc.next->next;
 944                 ioat_chan->pending++;
 945                 ioat_chan->dmacount++;
 946
 947                 /* try to get a few more descriptors */
 948                 for (i = 16; i; i--) {
 949                         desc = ioat_dma_alloc_descriptor(ioat_chan, GFP_ATOMIC);
 950                         if (!desc) {
 951                                 dev_err(&ioat_chan->device->pdev->dev,
 952                                         "alloc failed\n");
 953                                 break;
 954                         }
 955                         list_add_tail(&desc->node, ioat_chan->used_desc.next);
 956
 957                         desc->hw->next
 958                                 = to_ioat_desc(desc->node.next)->async_tx.phys;
 959                         to_ioat_desc(desc->node.prev)->hw->next
 960                                 = desc->async_tx.phys;
 961                         ioat_chan->desccount++;
 962                 }
 963
 964                 ioat_chan->used_desc.next = noop_desc->node.next;
 965         }
 966         new = to_ioat_desc(ioat_chan->used_desc.next);
 967         prefetch(new);
 968         ioat_chan->used_desc.next = new->node.next;
 969
 970         if (ioat_chan->used_desc.prev == NULL)
 971                 ioat_chan->used_desc.prev = &new->node;
 972
 973         prefetch(new->hw);
 974         return new;
 975 }
 976
 977 static struct ioat_desc_sw *ioat_dma_get_next_descriptor(
 978                                                 struct ioat_dma_chan *ioat_chan)
 979 {
 980         if (!ioat_chan)
 981                 return NULL;
 982
 983         switch (ioat_chan->device->version) {
 984         case IOAT_VER_1_2:
 985                 return ioat1_dma_get_next_descriptor(ioat_chan);
 986         case IOAT_VER_2_0:
 987         case IOAT_VER_3_0:
 988                 return ioat2_dma_get_next_descriptor(ioat_chan);
 989         }
 990         return NULL;
 991 }
 992
 993 static struct dma_async_tx_descriptor *ioat1_dma_prep_memcpy(
 994                                                 struct dma_chan *chan,
 995                                                 dma_addr_t dma_dest,
 996                                                 dma_addr_t dma_src,
 997                                                 size_t len,
 998                                                 unsigned long flags)
 999 {
1000         struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
1001         struct ioat_desc_sw *new;
1002
1003         spin_lock_bh(&ioat_chan->desc_lock);
1004         new = ioat_dma_get_next_descriptor(ioat_chan);
1005         spin_unlock_bh(&ioat_chan->desc_lock);
1006
1007         if (new) {
1008                 new->len = len;
1009                 new->dst = dma_dest;
1010                 new->src = dma_src;
1011                 new->async_tx.flags = flags;
1012                 return &new->async_tx;
1013         } else {
1014                 dev_err(&ioat_chan->device->pdev->dev,
1015                         "chan%d - get_next_desc failed: %d descs waiting, %d total desc\n",
1016                         chan_num(ioat_chan), ioat_chan->dmacount, ioat_chan->desccount);
1017                 return NULL;
1018         }
1019 }
1020
1021 static struct dma_async_tx_descriptor *ioat2_dma_prep_memcpy(
1022                                                 struct dma_chan *chan,
1023                                                 dma_addr_t dma_dest,
1024                                                 dma_addr_t dma_src,
1025                                                 size_t len,
1026                                                 unsigned long flags)
1027 {
1028         struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
1029         struct ioat_desc_sw *new;
1030
1031         spin_lock_bh(&ioat_chan->desc_lock);
1032         new = ioat2_dma_get_next_descriptor(ioat_chan);
1033
1034         /*
1035          * leave ioat_chan->desc_lock set in ioat 2 path
1036          * it will get unlocked at end of tx_submit
1037          */
1038
1039         if (new) {
1040                 new->len = len;
1041                 new->dst = dma_dest;
1042                 new->src = dma_src;
1043                 new->async_tx.flags = flags;
1044                 return &new->async_tx;
1045         } else {
1046                 spin_unlock_bh(&ioat_chan->desc_lock);
1047                 dev_err(&ioat_chan->device->pdev->dev,
1048                         "chan%d - get_next_desc failed: %d descs waiting, %d total desc\n",
1049                         chan_num(ioat_chan), ioat_chan->dmacount, ioat_chan->desccount);
1050                 return NULL;
1051         }
1052 }
1053
1054 static void ioat_dma_cleanup_tasklet(unsigned long data)
1055 {
1056         struct ioat_dma_chan *chan = (void *)data;
1057         ioat_dma_memcpy_cleanup(chan);
1058         writew(IOAT_CHANCTRL_INT_DISABLE,
1059                chan->reg_base + IOAT_CHANCTRL_OFFSET);
1060 }
1061
1062 static void
1063 ioat_dma_unmap(struct ioat_dma_chan *ioat_chan, struct ioat_desc_sw *desc)
1064 {
1065         /*
1066          * yes we are unmapping both _page and _single
1067          * alloc'd regions with unmap_page. Is this
1068          * *really* that bad?
1069          */
1070         if (!(desc->async_tx.flags & DMA_COMPL_SKIP_DEST_UNMAP))
1071                 pci_unmap_page(ioat_chan->device->pdev,
1072                                 pci_unmap_addr(desc, dst),
1073                                 pci_unmap_len(desc, len),
1074                                 PCI_DMA_FROMDEVICE);
1075
1076         if (!(desc->async_tx.flags & DMA_COMPL_SKIP_SRC_UNMAP))
1077                 pci_unmap_page(ioat_chan->device->pdev,
1078                                 pci_unmap_addr(desc, src),
1079                                 pci_unmap_len(desc, len),
1080                                 PCI_DMA_TODEVICE);
1081 }
1082
1083 /**
1084  * ioat_dma_memcpy_cleanup - cleanup up finished descriptors
1085  * @chan: ioat channel to be cleaned up
1086  */
1087 static void ioat_dma_memcpy_cleanup(struct ioat_dma_chan *ioat_chan)
1088 {
1089         unsigned long phys_complete;
1090         struct ioat_desc_sw *desc, *_desc;
1091         dma_cookie_t cookie = 0;
1092         unsigned long desc_phys;
1093         struct ioat_desc_sw *latest_desc;
1094
1095         prefetch(ioat_chan->completion_virt);
1096
1097         if (!spin_trylock_bh(&ioat_chan->cleanup_lock))
1098                 return;
1099
1100         /* The completion writeback can happen at any time,
1101            so reads by the driver need to be atomic operations
1102            The descriptor physical addresses are limited to 32-bits
1103            when the CPU can only do a 32-bit mov */
1104
1105 #if (BITS_PER_LONG == 64)
1106         phys_complete =
1107                 ioat_chan->completion_virt->full
1108                 & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_ADDR;
1109 #else
1110         phys_complete =
1111                 ioat_chan->completion_virt->low & IOAT_LOW_COMPLETION_MASK;
1112 #endif
1113
1114         if ((ioat_chan->completion_virt->full
1115                 & IOAT_CHANSTS_DMA_TRANSFER_STATUS) ==
1116                                 IOAT_CHANSTS_DMA_TRANSFER_STATUS_HALTED) {
1117                 dev_err(&ioat_chan->device->pdev->dev,
1118                         "Channel halted, chanerr = %x\n",
1119                         readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET));
1120
1121                 /* TODO do something to salvage the situation */
1122         }
1123
1124         if (phys_complete == ioat_chan->last_completion) {
1125                 spin_unlock_bh(&ioat_chan->cleanup_lock);
1126                 /*
1127                  * perhaps we're stuck so hard that the watchdog can't go off?
1128                  * try to catch it after 2 seconds
1129                  */
1130                 if (ioat_chan->device->version != IOAT_VER_3_0) {
1131                         if (time_after(jiffies,
1132                                        ioat_chan->last_completion_time + HZ*WATCHDOG_DELAY)) {
1133                                 ioat_dma_chan_watchdog(&(ioat_chan->device->work.work));
1134                                 ioat_chan->last_completion_time = jiffies;
1135                         }
1136                 }
1137                 return;
1138         }
1139         ioat_chan->last_completion_time = jiffies;
1140
1141         cookie = 0;
1142         if (!spin_trylock_bh(&ioat_chan->desc_lock)) {
1143                 spin_unlock_bh(&ioat_chan->cleanup_lock);
1144                 return;
1145         }
1146
1147         switch (ioat_chan->device->version) {
1148         case IOAT_VER_1_2:
1149                 list_for_each_entry_safe(desc, _desc,
1150                                          &ioat_chan->used_desc, node) {
1151
1152                         /*
1153                          * Incoming DMA requests may use multiple descriptors,
1154                          * due to exceeding xfercap, perhaps. If so, only the
1155                          * last one will have a cookie, and require unmapping.
1156                          */
1157                         if (desc->async_tx.cookie) {
1158                                 cookie = desc->async_tx.cookie;
1159                                 ioat_dma_unmap(ioat_chan, desc);
1160                                 if (desc->async_tx.callback) {
1161                                         desc->async_tx.callback(desc->async_tx.callback_param);
1162                                         desc->async_tx.callback = NULL;
1163                                 }
1164                         }
1165
1166                         if (desc->async_tx.phys != phys_complete) {
1167                                 /*
1168                                  * a completed entry, but not the last, so clean
1169                                  * up if the client is done with the descriptor
1170                                  */
1171                                 if (async_tx_test_ack(&desc->async_tx)) {
1172                                         list_del(&desc->node);
1173                                         list_add_tail(&desc->node,
1174                                                       &ioat_chan->free_desc);
1175                                 } else
1176                                         desc->async_tx.cookie = 0;
1177                         } else {
1178                                 /*
1179                                  * last used desc. Do not remove, so we can
1180                                  * append from it, but don't look at it next
1181                                  * time, either
1182                                  */
1183                                 desc->async_tx.cookie = 0;
1184
1185                                 /* TODO check status bits? */
1186                                 break;
1187                         }
1188                 }
1189                 break;
1190         case IOAT_VER_2_0:
1191         case IOAT_VER_3_0:
1192                 /* has some other thread has already cleaned up? */
1193                 if (ioat_chan->used_desc.prev == NULL)
1194                         break;
1195
1196                 /* work backwards to find latest finished desc */
1197                 desc = to_ioat_desc(ioat_chan->used_desc.next);
1198                 latest_desc = NULL;
1199                 do {
1200                         desc = to_ioat_desc(desc->node.prev);
1201                         desc_phys = (unsigned long)desc->async_tx.phys
1202                                        & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_ADDR;
1203                         if (desc_phys == phys_complete) {
1204                                 latest_desc = desc;
1205                                 break;
1206                         }
1207                 } while (&desc->node != ioat_chan->used_desc.prev);
1208
1209                 if (latest_desc != NULL) {
1210
1211                         /* work forwards to clear finished descriptors */
1212                         for (desc = to_ioat_desc(ioat_chan->used_desc.prev);
1213                              &desc->node != latest_desc->node.next &&
1214                              &desc->node != ioat_chan->used_desc.next;
1215                              desc = to_ioat_desc(desc->node.next)) {
1216                                 if (desc->async_tx.cookie) {
1217                                         cookie = desc->async_tx.cookie;
1218                                         desc->async_tx.cookie = 0;
1219                                         ioat_dma_unmap(ioat_chan, desc);
1220                                         if (desc->async_tx.callback) {
1221                                                 desc->async_tx.callback(desc->async_tx.callback_param);
1222                                                 desc->async_tx.callback = NULL;
1223                                         }
1224                                 }
1225                         }
1226
1227                         /* move used.prev up beyond those that are finished */
1228                         if (&desc->node == ioat_chan->used_desc.next)
1229                                 ioat_chan->used_desc.prev = NULL;
1230                         else
1231                                 ioat_chan->used_desc.prev = &desc->node;
1232                 }
1233                 break;
1234         }
1235
1236         spin_unlock_bh(&ioat_chan->desc_lock);
1237
1238         ioat_chan->last_completion = phys_complete;
1239         if (cookie != 0)
1240                 ioat_chan->completed_cookie = cookie;
1241
1242         spin_unlock_bh(&ioat_chan->cleanup_lock);
1243 }
1244
1245 /**
1246  * ioat_dma_is_complete - poll the status of a IOAT DMA transaction
1247  * @chan: IOAT DMA channel handle
1248  * @cookie: DMA transaction identifier
1249  * @done: if not %NULL, updated with last completed transaction
1250  * @used: if not %NULL, updated with last used transaction
1251  */
1252 static enum dma_status ioat_dma_is_complete(struct dma_chan *chan,
1253                                             dma_cookie_t cookie,
1254                                             dma_cookie_t *done,
1255                                             dma_cookie_t *used)
1256 {
1257         struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
1258         dma_cookie_t last_used;
1259         dma_cookie_t last_complete;
1260         enum dma_status ret;
1261
1262         last_used = chan->cookie;
1263         last_complete = ioat_chan->completed_cookie;
1264         ioat_chan->watchdog_tcp_cookie = cookie;
1265
1266         if (done)
1267                 *done = last_complete;
1268         if (used)
1269                 *used = last_used;
1270
1271         ret = dma_async_is_complete(cookie, last_complete, last_used);
1272         if (ret == DMA_SUCCESS)
1273                 return ret;
1274
1275         ioat_dma_memcpy_cleanup(ioat_chan);
1276
1277         last_used = chan->cookie;
1278         last_complete = ioat_chan->completed_cookie;
1279
1280         if (done)
1281                 *done = last_complete;
1282         if (used)
1283                 *used = last_used;
1284
1285         return dma_async_is_complete(cookie, last_complete, last_used);
1286 }
1287
1288 static void ioat_dma_start_null_desc(struct ioat_dma_chan *ioat_chan)
1289 {
1290         struct ioat_desc_sw *desc;
1291
1292         spin_lock_bh(&ioat_chan->desc_lock);
1293
1294         desc = ioat_dma_get_next_descriptor(ioat_chan);
1295
1296         if (!desc) {
1297                 dev_err(&ioat_chan->device->pdev->dev,
1298                         "Unable to start null desc - get next desc failed\n");
1299                 spin_unlock_bh(&ioat_chan->desc_lock);
1300                 return;
1301         }
1302
1303         desc->hw->ctl = IOAT_DMA_DESCRIPTOR_NUL
1304                                 | IOAT_DMA_DESCRIPTOR_CTL_INT_GN
1305                                 | IOAT_DMA_DESCRIPTOR_CTL_CP_STS;
1306         /* set size to non-zero value (channel returns error when size is 0) */
1307         desc->hw->size = NULL_DESC_BUFFER_SIZE;
1308         desc->hw->src_addr = 0;
1309         desc->hw->dst_addr = 0;
1310         async_tx_ack(&desc->async_tx);
1311         switch (ioat_chan->device->version) {
1312         case IOAT_VER_1_2:
1313                 desc->hw->next = 0;
1314                 list_add_tail(&desc->node, &ioat_chan->used_desc);
1315
1316                 writel(((u64) desc->async_tx.phys) & 0x00000000FFFFFFFF,
1317                        ioat_chan->reg_base + IOAT1_CHAINADDR_OFFSET_LOW);
1318                 writel(((u64) desc->async_tx.phys) >> 32,
1319                        ioat_chan->reg_base + IOAT1_CHAINADDR_OFFSET_HIGH);
1320
1321                 writeb(IOAT_CHANCMD_START, ioat_chan->reg_base
1322                         + IOAT_CHANCMD_OFFSET(ioat_chan->device->version));
1323                 break;
1324         case IOAT_VER_2_0:
1325         case IOAT_VER_3_0:
1326                 writel(((u64) desc->async_tx.phys) & 0x00000000FFFFFFFF,
1327                        ioat_chan->reg_base + IOAT2_CHAINADDR_OFFSET_LOW);
1328                 writel(((u64) desc->async_tx.phys) >> 32,
1329                        ioat_chan->reg_base + IOAT2_CHAINADDR_OFFSET_HIGH);
1330
1331                 ioat_chan->dmacount++;
1332                 __ioat2_dma_memcpy_issue_pending(ioat_chan);
1333                 break;
1334         }
1335         spin_unlock_bh(&ioat_chan->desc_lock);
1336 }
1337
1338 /*
1339  * Perform a IOAT transaction to verify the HW works.
1340  */
1341 #define IOAT_TEST_SIZE 2000
1342
1343 static void ioat_dma_test_callback(void *dma_async_param)
1344 {
1345         struct completion *cmp = dma_async_param;
1346
1347         complete(cmp);
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         struct completion cmp;
1365
1366         src = kzalloc(sizeof(u8) * IOAT_TEST_SIZE, GFP_KERNEL);
1367         if (!src)
1368                 return -ENOMEM;
1369         dest = kzalloc(sizeof(u8) * IOAT_TEST_SIZE, GFP_KERNEL);
1370         if (!dest) {
1371                 kfree(src);
1372                 return -ENOMEM;
1373         }
1374
1375         /* Fill in src buffer */
1376         for (i = 0; i < IOAT_TEST_SIZE; i++)
1377                 src[i] = (u8)i;
1378
1379         /* Start copy, using first DMA channel */
1380         dma_chan = container_of(device->common.channels.next,
1381                                 struct dma_chan,
1382                                 device_node);
1383         if (device->common.device_alloc_chan_resources(dma_chan) < 1) {
1384                 dev_err(&device->pdev->dev,
1385                         "selftest cannot allocate chan resource\n");
1386                 err = -ENODEV;
1387                 goto out;
1388         }
1389
1390         dma_src = dma_map_single(dma_chan->device->dev, src, IOAT_TEST_SIZE,
1391                                  DMA_TO_DEVICE);
1392         dma_dest = dma_map_single(dma_chan->device->dev, dest, IOAT_TEST_SIZE,
1393                                   DMA_FROM_DEVICE);
1394         tx = device->common.device_prep_dma_memcpy(dma_chan, dma_dest, dma_src,
1395                                                    IOAT_TEST_SIZE, 0);
1396         if (!tx) {
1397                 dev_err(&device->pdev->dev,
1398                         "Self-test prep failed, disabling\n");
1399                 err = -ENODEV;
1400                 goto free_resources;
1401         }
1402
1403         async_tx_ack(tx);
1404         init_completion(&cmp);
1405         tx->callback = ioat_dma_test_callback;
1406         tx->callback_param = &cmp;
1407         cookie = tx->tx_submit(tx);
1408         if (cookie < 0) {
1409                 dev_err(&device->pdev->dev,
1410                         "Self-test setup failed, disabling\n");
1411                 err = -ENODEV;
1412                 goto free_resources;
1413         }
1414         device->common.device_issue_pending(dma_chan);
1415
1416         wait_for_completion_timeout(&cmp, msecs_to_jiffies(3000));
1417
1418         if (device->common.device_is_tx_complete(dma_chan, cookie, NULL, NULL)
1419                                         != DMA_SUCCESS) {
1420                 dev_err(&device->pdev->dev,
1421                         "Self-test copy timed out, disabling\n");
1422                 err = -ENODEV;
1423                 goto free_resources;
1424         }
1425         if (memcmp(src, dest, IOAT_TEST_SIZE)) {
1426                 dev_err(&device->pdev->dev,
1427                         "Self-test copy failed compare, disabling\n");
1428                 err = -ENODEV;
1429                 goto free_resources;
1430         }
1431
1432 free_resources:
1433         device->common.device_free_chan_resources(dma_chan);
1434 out:
1435         kfree(src);
1436         kfree(dest);
1437         return err;
1438 }
1439
1440 static char ioat_interrupt_style[32] = "msix";
1441 module_param_string(ioat_interrupt_style, ioat_interrupt_style,
1442                     sizeof(ioat_interrupt_style), 0644);
1443 MODULE_PARM_DESC(ioat_interrupt_style,
1444                  "set ioat interrupt style: msix (default), "
1445                  "msix-single-vector, msi, intx)");
1446
1447 /**
1448  * ioat_dma_setup_interrupts - setup interrupt handler
1449  * @device: ioat device
1450  */
1451 static int ioat_dma_setup_interrupts(struct ioatdma_device *device)
1452 {
1453         struct ioat_dma_chan *ioat_chan;
1454         int err, i, j, msixcnt;
1455         u8 intrctrl = 0;
1456
1457         if (!strcmp(ioat_interrupt_style, "msix"))
1458                 goto msix;
1459         if (!strcmp(ioat_interrupt_style, "msix-single-vector"))
1460                 goto msix_single_vector;
1461         if (!strcmp(ioat_interrupt_style, "msi"))
1462                 goto msi;
1463         if (!strcmp(ioat_interrupt_style, "intx"))
1464                 goto intx;
1465         dev_err(&device->pdev->dev, "invalid ioat_interrupt_style %s\n",
1466                 ioat_interrupt_style);
1467         goto err_no_irq;
1468
1469 msix:
1470         /* The number of MSI-X vectors should equal the number of channels */
1471         msixcnt = device->common.chancnt;
1472         for (i = 0; i < msixcnt; i++)
1473                 device->msix_entries[i].entry = i;
1474
1475         err = pci_enable_msix(device->pdev, device->msix_entries, msixcnt);
1476         if (err < 0)
1477                 goto msi;
1478         if (err > 0)
1479                 goto msix_single_vector;
1480
1481         for (i = 0; i < msixcnt; i++) {
1482                 ioat_chan = ioat_lookup_chan_by_index(device, i);
1483                 err = request_irq(device->msix_entries[i].vector,
1484                                   ioat_dma_do_interrupt_msix,
1485                                   0, "ioat-msix", ioat_chan);
1486                 if (err) {
1487                         for (j = 0; j < i; j++) {
1488                                 ioat_chan =
1489                                         ioat_lookup_chan_by_index(device, j);
1490                                 free_irq(device->msix_entries[j].vector,
1491                                          ioat_chan);
1492                         }
1493                         goto msix_single_vector;
1494                 }
1495         }
1496         intrctrl |= IOAT_INTRCTRL_MSIX_VECTOR_CONTROL;
1497         device->irq_mode = msix_multi_vector;
1498         goto done;
1499
1500 msix_single_vector:
1501         device->msix_entries[0].entry = 0;
1502         err = pci_enable_msix(device->pdev, device->msix_entries, 1);
1503         if (err)
1504                 goto msi;
1505
1506         err = request_irq(device->msix_entries[0].vector, ioat_dma_do_interrupt,
1507                           0, "ioat-msix", device);
1508         if (err) {
1509                 pci_disable_msix(device->pdev);
1510                 goto msi;
1511         }
1512         device->irq_mode = msix_single_vector;
1513         goto done;
1514
1515 msi:
1516         err = pci_enable_msi(device->pdev);
1517         if (err)
1518                 goto intx;
1519
1520         err = request_irq(device->pdev->irq, ioat_dma_do_interrupt,
1521                           0, "ioat-msi", device);
1522         if (err) {
1523                 pci_disable_msi(device->pdev);
1524                 goto intx;
1525         }
1526         /*
1527          * CB 1.2 devices need a bit set in configuration space to enable MSI
1528          */
1529         if (device->version == IOAT_VER_1_2) {
1530                 u32 dmactrl;
1531                 pci_read_config_dword(device->pdev,
1532                                       IOAT_PCI_DMACTRL_OFFSET, &dmactrl);
1533                 dmactrl |= IOAT_PCI_DMACTRL_MSI_EN;
1534                 pci_write_config_dword(device->pdev,
1535                                        IOAT_PCI_DMACTRL_OFFSET, dmactrl);
1536         }
1537         device->irq_mode = msi;
1538         goto done;
1539
1540 intx:
1541         err = request_irq(device->pdev->irq, ioat_dma_do_interrupt,
1542                           IRQF_SHARED, "ioat-intx", device);
1543         if (err)
1544                 goto err_no_irq;
1545         device->irq_mode = intx;
1546
1547 done:
1548         intrctrl |= IOAT_INTRCTRL_MASTER_INT_EN;
1549         writeb(intrctrl, device->reg_base + IOAT_INTRCTRL_OFFSET);
1550         return 0;
1551
1552 err_no_irq:
1553         /* Disable all interrupt generation */
1554         writeb(0, device->reg_base + IOAT_INTRCTRL_OFFSET);
1555         dev_err(&device->pdev->dev, "no usable interrupts\n");
1556         device->irq_mode = none;
1557         return -1;
1558 }
1559
1560 /**
1561  * ioat_dma_remove_interrupts - remove whatever interrupts were set
1562  * @device: ioat device
1563  */
1564 static void ioat_dma_remove_interrupts(struct ioatdma_device *device)
1565 {
1566         struct ioat_dma_chan *ioat_chan;
1567         int i;
1568
1569         /* Disable all interrupt generation */
1570         writeb(0, device->reg_base + IOAT_INTRCTRL_OFFSET);
1571
1572         switch (device->irq_mode) {
1573         case msix_multi_vector:
1574                 for (i = 0; i < device->common.chancnt; i++) {
1575                         ioat_chan = ioat_lookup_chan_by_index(device, i);
1576                         free_irq(device->msix_entries[i].vector, ioat_chan);
1577                 }
1578                 pci_disable_msix(device->pdev);
1579                 break;
1580         case msix_single_vector:
1581                 free_irq(device->msix_entries[0].vector, device);
1582                 pci_disable_msix(device->pdev);
1583                 break;
1584         case msi:
1585                 free_irq(device->pdev->irq, device);
1586                 pci_disable_msi(device->pdev);
1587                 break;
1588         case intx:
1589                 free_irq(device->pdev->irq, device);
1590                 break;
1591         case none:
1592                 dev_warn(&device->pdev->dev,
1593                          "call to %s without interrupts setup\n", __func__);
1594         }
1595         device->irq_mode = none;
1596 }
1597
1598 struct ioatdma_device *ioat_dma_probe(struct pci_dev *pdev,
1599                                       void __iomem *iobase)
1600 {
1601         int err;
1602         struct ioatdma_device *device;
1603
1604         device = kzalloc(sizeof(*device), GFP_KERNEL);
1605         if (!device) {
1606                 err = -ENOMEM;
1607                 goto err_kzalloc;
1608         }
1609         device->pdev = pdev;
1610         device->reg_base = iobase;
1611         device->version = readb(device->reg_base + IOAT_VER_OFFSET);
1612
1613         /* DMA coherent memory pool for DMA descriptor allocations */
1614         device->dma_pool = pci_pool_create("dma_desc_pool", pdev,
1615                                            sizeof(struct ioat_dma_descriptor),
1616                                            64, 0);
1617         if (!device->dma_pool) {
1618                 err = -ENOMEM;
1619                 goto err_dma_pool;
1620         }
1621
1622         device->completion_pool = pci_pool_create("completion_pool", pdev,
1623                                                   sizeof(u64), SMP_CACHE_BYTES,
1624                                                   SMP_CACHE_BYTES);
1625         if (!device->completion_pool) {
1626                 err = -ENOMEM;
1627                 goto err_completion_pool;
1628         }
1629
1630         INIT_LIST_HEAD(&device->common.channels);
1631         ioat_dma_enumerate_channels(device);
1632
1633         device->common.device_alloc_chan_resources =
1634                                                 ioat_dma_alloc_chan_resources;
1635         device->common.device_free_chan_resources =
1636                                                 ioat_dma_free_chan_resources;
1637         device->common.dev = &pdev->dev;
1638
1639         dma_cap_set(DMA_MEMCPY, device->common.cap_mask);
1640         device->common.device_is_tx_complete = ioat_dma_is_complete;
1641         switch (device->version) {
1642         case IOAT_VER_1_2:
1643                 device->common.device_prep_dma_memcpy = ioat1_dma_prep_memcpy;
1644                 device->common.device_issue_pending =
1645                                                 ioat1_dma_memcpy_issue_pending;
1646                 break;
1647         case IOAT_VER_2_0:
1648         case IOAT_VER_3_0:
1649                 device->common.device_prep_dma_memcpy = ioat2_dma_prep_memcpy;
1650                 device->common.device_issue_pending =
1651                                                 ioat2_dma_memcpy_issue_pending;
1652                 break;
1653         }
1654
1655         dev_err(&device->pdev->dev,
1656                 "Intel(R) I/OAT DMA Engine found,"
1657                 " %d channels, device version 0x%02x, driver version %s\n",
1658                 device->common.chancnt, device->version, IOAT_DMA_VERSION);
1659
1660         err = ioat_dma_setup_interrupts(device);
1661         if (err)
1662                 goto err_setup_interrupts;
1663
1664         err = ioat_dma_self_test(device);
1665         if (err)
1666                 goto err_self_test;
1667
1668         ioat_set_tcp_copy_break(device);
1669
1670         dma_async_device_register(&device->common);
1671
1672         if (device->version != IOAT_VER_3_0) {
1673                 INIT_DELAYED_WORK(&device->work, ioat_dma_chan_watchdog);
1674                 schedule_delayed_work(&device->work,
1675                                       WATCHDOG_DELAY);
1676         }
1677
1678         return device;
1679
1680 err_self_test:
1681         ioat_dma_remove_interrupts(device);
1682 err_setup_interrupts:
1683         pci_pool_destroy(device->completion_pool);
1684 err_completion_pool:
1685         pci_pool_destroy(device->dma_pool);
1686 err_dma_pool:
1687         kfree(device);
1688 err_kzalloc:
1689         dev_err(&pdev->dev,
1690                 "Intel(R) I/OAT DMA Engine initialization failed\n");
1691         return NULL;
1692 }
1693
1694 void ioat_dma_remove(struct ioatdma_device *device)
1695 {
1696         struct dma_chan *chan, *_chan;
1697         struct ioat_dma_chan *ioat_chan;
1698
1699         ioat_dma_remove_interrupts(device);
1700
1701         dma_async_device_unregister(&device->common);
1702
1703         pci_pool_destroy(device->dma_pool);
1704         pci_pool_destroy(device->completion_pool);
1705
1706         iounmap(device->reg_base);
1707         pci_release_regions(device->pdev);
1708         pci_disable_device(device->pdev);
1709
1710         if (device->version != IOAT_VER_3_0) {
1711                 cancel_delayed_work(&device->work);
1712         }
1713
1714         list_for_each_entry_safe(chan, _chan,
1715                                  &device->common.channels, device_node) {
1716                 ioat_chan = to_ioat_chan(chan);
1717                 list_del(&chan->device_node);
1718                 kfree(ioat_chan);
1719         }
1720         kfree(device);
1721 }
1722