drivers/ntb/ntb_hw.c

   1 /*
   2  * This file is provided under a dual BSD/GPLv2 license.  When using or
   3  *   redistributing this file, you may do so under either license.
   4  *
   5  *   GPL LICENSE SUMMARY
   6  *
   7  *   Copyright(c) 2012 Intel Corporation. All rights reserved.
   8  *
   9  *   This program is free software; you can redistribute it and/or modify
  10  *   it under the terms of version 2 of the GNU General Public License as
  11  *   published by the Free Software Foundation.
  12  *
  13  *   BSD LICENSE
  14  *
  15  *   Copyright(c) 2012 Intel Corporation. All rights reserved.
  16  *
  17  *   Redistribution and use in source and binary forms, with or without
  18  *   modification, are permitted provided that the following conditions
  19  *   are met:
  20  *
  21  *     * Redistributions of source code must retain the above copyright
  22  *       notice, this list of conditions and the following disclaimer.
  23  *     * Redistributions in binary form must reproduce the above copy
  24  *       notice, this list of conditions and the following disclaimer in
  25  *       the documentation and/or other materials provided with the
  26  *       distribution.
  27  *     * Neither the name of Intel Corporation nor the names of its
  28  *       contributors may be used to endorse or promote products derived
  29  *       from this software without specific prior written permission.
  30  *
  31  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  34  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  36  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  37  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  38  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  39  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  40  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  41  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  42  *
  43  * Intel PCIe NTB Linux driver
  44  *
  45  * Contact Information:
  46  * Jon Mason <jon.mason@intel.com>
  47  */
  48 #include <linux/debugfs.h>
  49 #include <linux/delay.h>
  50 #include <linux/init.h>
  51 #include <linux/interrupt.h>
  52 #include <linux/module.h>
  53 #include <linux/pci.h>
  54 #include <linux/random.h>
  55 #include <linux/slab.h>
  56 #include "ntb_hw.h"
  57 #include "ntb_regs.h"
  58
  59 #define NTB_NAME        "Intel(R) PCI-E Non-Transparent Bridge Driver"
  60 #define NTB_VER         "1.0"
  61
  62 MODULE_DESCRIPTION(NTB_NAME);
  63 MODULE_VERSION(NTB_VER);
  64 MODULE_LICENSE("Dual BSD/GPL");
  65 MODULE_AUTHOR("Intel Corporation");
  66
  67 static bool xeon_errata_workaround = true;
  68 module_param(xeon_errata_workaround, bool, 0644);
  69 MODULE_PARM_DESC(xeon_errata_workaround, "Workaround for the Xeon Errata");
  70
  71 enum {
  72         NTB_CONN_TRANSPARENT = 0,
  73         NTB_CONN_B2B,
  74         NTB_CONN_RP,
  75 };
  76
  77 enum {
  78         NTB_DEV_USD = 0,
  79         NTB_DEV_DSD,
  80 };
  81
  82 enum {
  83         SNB_HW = 0,
  84         BWD_HW,
  85 };
  86
  87 static struct dentry *debugfs_dir;
  88
  89 #define BWD_LINK_RECOVERY_TIME  500
  90
  91 /* Translate memory window 0,1 to BAR 2,4 */
  92 #define MW_TO_BAR(mw)   (mw * NTB_MAX_NUM_MW + 2)
  93
  94 static const struct pci_device_id ntb_pci_tbl[] = {
  95         {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_BWD)},
  96         {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_JSF)},
  97         {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_SNB)},
  98         {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_IVT)},
  99         {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_HSX)},
 100         {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_PS_JSF)},
 101         {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_PS_SNB)},
 102         {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_PS_IVT)},
 103         {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_PS_HSX)},
 104         {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_SS_JSF)},
 105         {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_SS_SNB)},
 106         {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_SS_IVT)},
 107         {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_SS_HSX)},
 108         {0}
 109 };
 110 MODULE_DEVICE_TABLE(pci, ntb_pci_tbl);
 111
 112 /**
 113  * ntb_register_event_callback() - register event callback
 114  * @ndev: pointer to ntb_device instance
 115  * @func: callback function to register
 116  *
 117  * This function registers a callback for any HW driver events such as link
 118  * up/down, power management notices and etc.
 119  *
 120  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 121  */
 122 int ntb_register_event_callback(struct ntb_device *ndev,
 123                                 void (*func)(void *handle,
 124                                              enum ntb_hw_event event))
 125 {
 126         if (ndev->event_cb)
 127                 return -EINVAL;
 128
 129         ndev->event_cb = func;
 130
 131         return 0;
 132 }
 133
 134 /**
 135  * ntb_unregister_event_callback() - unregisters the event callback
 136  * @ndev: pointer to ntb_device instance
 137  *
 138  * This function unregisters the existing callback from transport
 139  */
 140 void ntb_unregister_event_callback(struct ntb_device *ndev)
 141 {
 142         ndev->event_cb = NULL;
 143 }
 144
 145 static void ntb_irq_work(unsigned long data)
 146 {
 147         struct ntb_db_cb *db_cb = (struct ntb_db_cb *)data;
 148         int rc;
 149
 150         rc = db_cb->callback(db_cb->data, db_cb->db_num);
 151         if (rc)
 152                 tasklet_schedule(&db_cb->irq_work);
 153         else {
 154                 struct ntb_device *ndev = db_cb->ndev;
 155                 unsigned long mask;
 156
 157                 mask = readw(ndev->reg_ofs.ldb_mask);
 158                 clear_bit(db_cb->db_num * ndev->bits_per_vector, &mask);
 159                 writew(mask, ndev->reg_ofs.ldb_mask);
 160         }
 161 }
 162
 163 /**
 164  * ntb_register_db_callback() - register a callback for doorbell interrupt
 165  * @ndev: pointer to ntb_device instance
 166  * @idx: doorbell index to register callback, zero based
 167  * @data: pointer to be returned to caller with every callback
 168  * @func: callback function to register
 169  *
 170  * This function registers a callback function for the doorbell interrupt
 171  * on the primary side. The function will unmask the doorbell as well to
 172  * allow interrupt.
 173  *
 174  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 175  */
 176 int ntb_register_db_callback(struct ntb_device *ndev, unsigned int idx,
 177                              void *data, int (*func)(void *data, int db_num))
 178 {
 179         unsigned long mask;
 180
 181         if (idx >= ndev->max_cbs || ndev->db_cb[idx].callback) {
 182                 dev_warn(&ndev->pdev->dev, "Invalid Index.\n");
 183                 return -EINVAL;
 184         }
 185
 186         ndev->db_cb[idx].callback = func;
 187         ndev->db_cb[idx].data = data;
 188         ndev->db_cb[idx].ndev = ndev;
 189
 190         tasklet_init(&ndev->db_cb[idx].irq_work, ntb_irq_work,
 191                      (unsigned long) &ndev->db_cb[idx]);
 192
 193         /* unmask interrupt */
 194         mask = readw(ndev->reg_ofs.ldb_mask);
 195         clear_bit(idx * ndev->bits_per_vector, &mask);
 196         writew(mask, ndev->reg_ofs.ldb_mask);
 197
 198         return 0;
 199 }
 200
 201 /**
 202  * ntb_unregister_db_callback() - unregister a callback for doorbell interrupt
 203  * @ndev: pointer to ntb_device instance
 204  * @idx: doorbell index to register callback, zero based
 205  *
 206  * This function unregisters a callback function for the doorbell interrupt
 207  * on the primary side. The function will also mask the said doorbell.
 208  */
 209 void ntb_unregister_db_callback(struct ntb_device *ndev, unsigned int idx)
 210 {
 211         unsigned long mask;
 212
 213         if (idx >= ndev->max_cbs || !ndev->db_cb[idx].callback)
 214                 return;
 215
 216         mask = readw(ndev->reg_ofs.ldb_mask);
 217         set_bit(idx * ndev->bits_per_vector, &mask);
 218         writew(mask, ndev->reg_ofs.ldb_mask);
 219
 220         tasklet_disable(&ndev->db_cb[idx].irq_work);
 221
 222         ndev->db_cb[idx].callback = NULL;
 223 }
 224
 225 /**
 226  * ntb_find_transport() - find the transport pointer
 227  * @transport: pointer to pci device
 228  *
 229  * Given the pci device pointer, return the transport pointer passed in when
 230  * the transport attached when it was inited.
 231  *
 232  * RETURNS: pointer to transport.
 233  */
 234 void *ntb_find_transport(struct pci_dev *pdev)
 235 {
 236         struct ntb_device *ndev = pci_get_drvdata(pdev);
 237         return ndev->ntb_transport;
 238 }
 239
 240 /**
 241  * ntb_register_transport() - Register NTB transport with NTB HW driver
 242  * @transport: transport identifier
 243  *
 244  * This function allows a transport to reserve the hardware driver for
 245  * NTB usage.
 246  *
 247  * RETURNS: pointer to ntb_device, NULL on error.
 248  */
 249 struct ntb_device *ntb_register_transport(struct pci_dev *pdev, void *transport)
 250 {
 251         struct ntb_device *ndev = pci_get_drvdata(pdev);
 252
 253         if (ndev->ntb_transport)
 254                 return NULL;
 255
 256         ndev->ntb_transport = transport;
 257         return ndev;
 258 }
 259
 260 /**
 261  * ntb_unregister_transport() - Unregister the transport with the NTB HW driver
 262  * @ndev - ntb_device of the transport to be freed
 263  *
 264  * This function unregisters the transport from the HW driver and performs any
 265  * necessary cleanups.
 266  */
 267 void ntb_unregister_transport(struct ntb_device *ndev)
 268 {
 269         int i;
 270
 271         if (!ndev->ntb_transport)
 272                 return;
 273
 274         for (i = 0; i < ndev->max_cbs; i++)
 275                 ntb_unregister_db_callback(ndev, i);
 276
 277         ntb_unregister_event_callback(ndev);
 278         ndev->ntb_transport = NULL;
 279 }
 280
 281 /**
 282  * ntb_write_local_spad() - write to the secondary scratchpad register
 283  * @ndev: pointer to ntb_device instance
 284  * @idx: index to the scratchpad register, 0 based
 285  * @val: the data value to put into the register
 286  *
 287  * This function allows writing of a 32bit value to the indexed scratchpad
 288  * register. This writes over the data mirrored to the local scratchpad register
 289  * by the remote system.
 290  *
 291  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 292  */
 293 int ntb_write_local_spad(struct ntb_device *ndev, unsigned int idx, u32 val)
 294 {
 295         if (idx >= ndev->limits.max_spads)
 296                 return -EINVAL;
 297
 298         dev_dbg(&ndev->pdev->dev, "Writing %x to local scratch pad index %d\n",
 299                 val, idx);
 300         writel(val, ndev->reg_ofs.spad_read + idx * 4);
 301
 302         return 0;
 303 }
 304
 305 /**
 306  * ntb_read_local_spad() - read from the primary scratchpad register
 307  * @ndev: pointer to ntb_device instance
 308  * @idx: index to scratchpad register, 0 based
 309  * @val: pointer to 32bit integer for storing the register value
 310  *
 311  * This function allows reading of the 32bit scratchpad register on
 312  * the primary (internal) side.  This allows the local system to read data
 313  * written and mirrored to the scratchpad register by the remote system.
 314  *
 315  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 316  */
 317 int ntb_read_local_spad(struct ntb_device *ndev, unsigned int idx, u32 *val)
 318 {
 319         if (idx >= ndev->limits.max_spads)
 320                 return -EINVAL;
 321
 322         *val = readl(ndev->reg_ofs.spad_write + idx * 4);
 323         dev_dbg(&ndev->pdev->dev,
 324                 "Reading %x from local scratch pad index %d\n", *val, idx);
 325
 326         return 0;
 327 }
 328
 329 /**
 330  * ntb_write_remote_spad() - write to the secondary scratchpad register
 331  * @ndev: pointer to ntb_device instance
 332  * @idx: index to the scratchpad register, 0 based
 333  * @val: the data value to put into the register
 334  *
 335  * This function allows writing of a 32bit value to the indexed scratchpad
 336  * register. The register resides on the secondary (external) side.  This allows
 337  * the local system to write data to be mirrored to the remote systems
 338  * scratchpad register.
 339  *
 340  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 341  */
 342 int ntb_write_remote_spad(struct ntb_device *ndev, unsigned int idx, u32 val)
 343 {
 344         if (idx >= ndev->limits.max_spads)
 345                 return -EINVAL;
 346
 347         dev_dbg(&ndev->pdev->dev, "Writing %x to remote scratch pad index %d\n",
 348                 val, idx);
 349         writel(val, ndev->reg_ofs.spad_write + idx * 4);
 350
 351         return 0;
 352 }
 353
 354 /**
 355  * ntb_read_remote_spad() - read from the primary scratchpad register
 356  * @ndev: pointer to ntb_device instance
 357  * @idx: index to scratchpad register, 0 based
 358  * @val: pointer to 32bit integer for storing the register value
 359  *
 360  * This function allows reading of the 32bit scratchpad register on
 361  * the primary (internal) side.  This alloows the local system to read the data
 362  * it wrote to be mirrored on the remote system.
 363  *
 364  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 365  */
 366 int ntb_read_remote_spad(struct ntb_device *ndev, unsigned int idx, u32 *val)
 367 {
 368         if (idx >= ndev->limits.max_spads)
 369                 return -EINVAL;
 370
 371         *val = readl(ndev->reg_ofs.spad_read + idx * 4);
 372         dev_dbg(&ndev->pdev->dev,
 373                 "Reading %x from remote scratch pad index %d\n", *val, idx);
 374
 375         return 0;
 376 }
 377
 378 /**
 379  * ntb_get_mw_base() - get addr for the NTB memory window
 380  * @ndev: pointer to ntb_device instance
 381  * @mw: memory window number
 382  *
 383  * This function provides the base address of the memory window specified.
 384  *
 385  * RETURNS: address, or NULL on error.
 386  */
 387 resource_size_t ntb_get_mw_base(struct ntb_device *ndev, unsigned int mw)
 388 {
 389         if (mw >= ntb_max_mw(ndev))
 390                 return 0;
 391
 392         return pci_resource_start(ndev->pdev, MW_TO_BAR(mw));
 393 }
 394
 395 /**
 396  * ntb_get_mw_vbase() - get virtual addr for the NTB memory window
 397  * @ndev: pointer to ntb_device instance
 398  * @mw: memory window number
 399  *
 400  * This function provides the base virtual address of the memory window
 401  * specified.
 402  *
 403  * RETURNS: pointer to virtual address, or NULL on error.
 404  */
 405 void __iomem *ntb_get_mw_vbase(struct ntb_device *ndev, unsigned int mw)
 406 {
 407         if (mw >= ntb_max_mw(ndev))
 408                 return NULL;
 409
 410         return ndev->mw[mw].vbase;
 411 }
 412
 413 /**
 414  * ntb_get_mw_size() - return size of NTB memory window
 415  * @ndev: pointer to ntb_device instance
 416  * @mw: memory window number
 417  *
 418  * This function provides the physical size of the memory window specified
 419  *
 420  * RETURNS: the size of the memory window or zero on error
 421  */
 422 u64 ntb_get_mw_size(struct ntb_device *ndev, unsigned int mw)
 423 {
 424         if (mw >= ntb_max_mw(ndev))
 425                 return 0;
 426
 427         return ndev->mw[mw].bar_sz;
 428 }
 429
 430 /**
 431  * ntb_set_mw_addr - set the memory window address
 432  * @ndev: pointer to ntb_device instance
 433  * @mw: memory window number
 434  * @addr: base address for data
 435  *
 436  * This function sets the base physical address of the memory window.  This
 437  * memory address is where data from the remote system will be transfered into
 438  * or out of depending on how the transport is configured.
 439  */
 440 void ntb_set_mw_addr(struct ntb_device *ndev, unsigned int mw, u64 addr)
 441 {
 442         if (mw >= ntb_max_mw(ndev))
 443                 return;
 444
 445         dev_dbg(&ndev->pdev->dev, "Writing addr %Lx to BAR %d\n", addr,
 446                 MW_TO_BAR(mw));
 447
 448         ndev->mw[mw].phys_addr = addr;
 449
 450         switch (MW_TO_BAR(mw)) {
 451         case NTB_BAR_23:
 452                 writeq(addr, ndev->reg_ofs.bar2_xlat);
 453                 break;
 454         case NTB_BAR_45:
 455                 writeq(addr, ndev->reg_ofs.bar4_xlat);
 456                 break;
 457         }
 458 }
 459
 460 /**
 461  * ntb_ring_doorbell() - Set the doorbell on the secondary/external side
 462  * @ndev: pointer to ntb_device instance
 463  * @db: doorbell to ring
 464  *
 465  * This function allows triggering of a doorbell on the secondary/external
 466  * side that will initiate an interrupt on the remote host
 467  *
 468  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 469  */
 470 void ntb_ring_doorbell(struct ntb_device *ndev, unsigned int db)
 471 {
 472         dev_dbg(&ndev->pdev->dev, "%s: ringing doorbell %d\n", __func__, db);
 473
 474         if (ndev->hw_type == BWD_HW)
 475                 writeq((u64) 1 << db, ndev->reg_ofs.rdb);
 476         else
 477                 writew(((1 << ndev->bits_per_vector) - 1) <<
 478                        (db * ndev->bits_per_vector), ndev->reg_ofs.rdb);
 479 }
 480
 481 static void bwd_recover_link(struct ntb_device *ndev)
 482 {
 483         u32 status;
 484
 485         /* Driver resets the NTB ModPhy lanes - magic! */
 486         writeb(0xe0, ndev->reg_base + BWD_MODPHY_PCSREG6);
 487         writeb(0x40, ndev->reg_base + BWD_MODPHY_PCSREG4);
 488         writeb(0x60, ndev->reg_base + BWD_MODPHY_PCSREG4);
 489         writeb(0x60, ndev->reg_base + BWD_MODPHY_PCSREG6);
 490
 491         /* Driver waits 100ms to allow the NTB ModPhy to settle */
 492         msleep(100);
 493
 494         /* Clear AER Errors, write to clear */
 495         status = readl(ndev->reg_base + BWD_ERRCORSTS_OFFSET);
 496         dev_dbg(&ndev->pdev->dev, "ERRCORSTS = %x\n", status);
 497         status &= PCI_ERR_COR_REP_ROLL;
 498         writel(status, ndev->reg_base + BWD_ERRCORSTS_OFFSET);
 499
 500         /* Clear unexpected electrical idle event in LTSSM, write to clear */
 501         status = readl(ndev->reg_base + BWD_LTSSMERRSTS0_OFFSET);
 502         dev_dbg(&ndev->pdev->dev, "LTSSMERRSTS0 = %x\n", status);
 503         status |= BWD_LTSSMERRSTS0_UNEXPECTEDEI;
 504         writel(status, ndev->reg_base + BWD_LTSSMERRSTS0_OFFSET);
 505
 506         /* Clear DeSkew Buffer error, write to clear */
 507         status = readl(ndev->reg_base + BWD_DESKEWSTS_OFFSET);
 508         dev_dbg(&ndev->pdev->dev, "DESKEWSTS = %x\n", status);
 509         status |= BWD_DESKEWSTS_DBERR;
 510         writel(status, ndev->reg_base + BWD_DESKEWSTS_OFFSET);
 511
 512         status = readl(ndev->reg_base + BWD_IBSTERRRCRVSTS0_OFFSET);
 513         dev_dbg(&ndev->pdev->dev, "IBSTERRRCRVSTS0 = %x\n", status);
 514         status &= BWD_IBIST_ERR_OFLOW;
 515         writel(status, ndev->reg_base + BWD_IBSTERRRCRVSTS0_OFFSET);
 516
 517         /* Releases the NTB state machine to allow the link to retrain */
 518         status = readl(ndev->reg_base + BWD_LTSSMSTATEJMP_OFFSET);
 519         dev_dbg(&ndev->pdev->dev, "LTSSMSTATEJMP = %x\n", status);
 520         status &= ~BWD_LTSSMSTATEJMP_FORCEDETECT;
 521         writel(status, ndev->reg_base + BWD_LTSSMSTATEJMP_OFFSET);
 522 }
 523
 524 static void ntb_link_event(struct ntb_device *ndev, int link_state)
 525 {
 526         unsigned int event;
 527
 528         if (ndev->link_status == link_state)
 529                 return;
 530
 531         if (link_state == NTB_LINK_UP) {
 532                 u16 status;
 533
 534                 dev_info(&ndev->pdev->dev, "Link Up\n");
 535                 ndev->link_status = NTB_LINK_UP;
 536                 event = NTB_EVENT_HW_LINK_UP;
 537
 538                 if (ndev->hw_type == BWD_HW ||
 539                     ndev->conn_type == NTB_CONN_TRANSPARENT)
 540                         status = readw(ndev->reg_ofs.lnk_stat);
 541                 else {
 542                         int rc = pci_read_config_word(ndev->pdev,
 543                                                       SNB_LINK_STATUS_OFFSET,
 544                                                       &status);
 545                         if (rc)
 546                                 return;
 547                 }
 548
 549                 ndev->link_width = (status & NTB_LINK_WIDTH_MASK) >> 4;
 550                 ndev->link_speed = (status & NTB_LINK_SPEED_MASK);
 551                 dev_info(&ndev->pdev->dev, "Link Width %d, Link Speed %d\n",
 552                          ndev->link_width, ndev->link_speed);
 553         } else {
 554                 dev_info(&ndev->pdev->dev, "Link Down\n");
 555                 ndev->link_status = NTB_LINK_DOWN;
 556                 event = NTB_EVENT_HW_LINK_DOWN;
 557                 /* Don't modify link width/speed, we need it in link recovery */
 558         }
 559
 560         /* notify the upper layer if we have an event change */
 561         if (ndev->event_cb)
 562                 ndev->event_cb(ndev->ntb_transport, event);
 563 }
 564
 565 static int ntb_link_status(struct ntb_device *ndev)
 566 {
 567         int link_state;
 568
 569         if (ndev->hw_type == BWD_HW) {
 570                 u32 ntb_cntl;
 571
 572                 ntb_cntl = readl(ndev->reg_ofs.lnk_cntl);
 573                 if (ntb_cntl & BWD_CNTL_LINK_DOWN)
 574                         link_state = NTB_LINK_DOWN;
 575                 else
 576                         link_state = NTB_LINK_UP;
 577         } else {
 578                 u16 status;
 579                 int rc;
 580
 581                 rc = pci_read_config_word(ndev->pdev, SNB_LINK_STATUS_OFFSET,
 582                                           &status);
 583                 if (rc)
 584                         return rc;
 585
 586                 if (status & NTB_LINK_STATUS_ACTIVE)
 587                         link_state = NTB_LINK_UP;
 588                 else
 589                         link_state = NTB_LINK_DOWN;
 590         }
 591
 592         ntb_link_event(ndev, link_state);
 593
 594         return 0;
 595 }
 596
 597 static void bwd_link_recovery(struct work_struct *work)
 598 {
 599         struct ntb_device *ndev = container_of(work, struct ntb_device,
 600                                                lr_timer.work);
 601         u32 status32;
 602
 603         bwd_recover_link(ndev);
 604         /* There is a potential race between the 2 NTB devices recovering at the
 605          * same time.  If the times are the same, the link will not recover and
 606          * the driver will be stuck in this loop forever.  Add a random interval
 607          * to the recovery time to prevent this race.
 608          */
 609         msleep(BWD_LINK_RECOVERY_TIME + prandom_u32() % BWD_LINK_RECOVERY_TIME);
 610
 611         status32 = readl(ndev->reg_base + BWD_LTSSMSTATEJMP_OFFSET);
 612         if (status32 & BWD_LTSSMSTATEJMP_FORCEDETECT)
 613                 goto retry;
 614
 615         status32 = readl(ndev->reg_base + BWD_IBSTERRRCRVSTS0_OFFSET);
 616         if (status32 & BWD_IBIST_ERR_OFLOW)
 617                 goto retry;
 618
 619         status32 = readl(ndev->reg_ofs.lnk_cntl);
 620         if (!(status32 & BWD_CNTL_LINK_DOWN)) {
 621                 unsigned char speed, width;
 622                 u16 status16;
 623
 624                 status16 = readw(ndev->reg_ofs.lnk_stat);
 625                 width = (status16 & NTB_LINK_WIDTH_MASK) >> 4;
 626                 speed = (status16 & NTB_LINK_SPEED_MASK);
 627                 if (ndev->link_width != width || ndev->link_speed != speed)
 628                         goto retry;
 629         }
 630
 631         schedule_delayed_work(&ndev->hb_timer, NTB_HB_TIMEOUT);
 632         return;
 633
 634 retry:
 635         schedule_delayed_work(&ndev->lr_timer, NTB_HB_TIMEOUT);
 636 }
 637
 638 /* BWD doesn't have link status interrupt, poll on that platform */
 639 static void bwd_link_poll(struct work_struct *work)
 640 {
 641         struct ntb_device *ndev = container_of(work, struct ntb_device,
 642                                                hb_timer.work);
 643         unsigned long ts = jiffies;
 644
 645         /* If we haven't gotten an interrupt in a while, check the BWD link
 646          * status bit
 647          */
 648         if (ts > ndev->last_ts + NTB_HB_TIMEOUT) {
 649                 int rc = ntb_link_status(ndev);
 650                 if (rc)
 651                         dev_err(&ndev->pdev->dev,
 652                                 "Error determining link status\n");
 653
 654                 /* Check to see if a link error is the cause of the link down */
 655                 if (ndev->link_status == NTB_LINK_DOWN) {
 656                         u32 status32 = readl(ndev->reg_base +
 657                                              BWD_LTSSMSTATEJMP_OFFSET);
 658                         if (status32 & BWD_LTSSMSTATEJMP_FORCEDETECT) {
 659                                 schedule_delayed_work(&ndev->lr_timer, 0);
 660                                 return;
 661                         }
 662                 }
 663         }
 664
 665         schedule_delayed_work(&ndev->hb_timer, NTB_HB_TIMEOUT);
 666 }
 667
 668 static int ntb_xeon_setup(struct ntb_device *ndev)
 669 {
 670         int rc;
 671         u8 val;
 672
 673         ndev->hw_type = SNB_HW;
 674
 675         rc = pci_read_config_byte(ndev->pdev, NTB_PPD_OFFSET, &val);
 676         if (rc)
 677                 return rc;
 678
 679         if (val & SNB_PPD_DEV_TYPE)
 680                 ndev->dev_type = NTB_DEV_USD;
 681         else
 682                 ndev->dev_type = NTB_DEV_DSD;
 683
 684         switch (val & SNB_PPD_CONN_TYPE) {
 685         case NTB_CONN_B2B:
 686                 dev_info(&ndev->pdev->dev, "Conn Type = B2B\n");
 687                 ndev->conn_type = NTB_CONN_B2B;
 688                 ndev->reg_ofs.ldb = ndev->reg_base + SNB_PDOORBELL_OFFSET;
 689                 ndev->reg_ofs.ldb_mask = ndev->reg_base + SNB_PDBMSK_OFFSET;
 690                 ndev->reg_ofs.spad_read = ndev->reg_base + SNB_SPAD_OFFSET;
 691                 ndev->reg_ofs.bar2_xlat = ndev->reg_base + SNB_SBAR2XLAT_OFFSET;
 692                 ndev->reg_ofs.bar4_xlat = ndev->reg_base + SNB_SBAR4XLAT_OFFSET;
 693                 ndev->limits.max_spads = SNB_MAX_B2B_SPADS;
 694
 695                 /* There is a Xeon hardware errata related to writes to
 696                  * SDOORBELL or B2BDOORBELL in conjunction with inbound access
 697                  * to NTB MMIO Space, which may hang the system.  To workaround
 698                  * this use the second memory window to access the interrupt and
 699                  * scratch pad registers on the remote system.
 700                  */
 701                 if (xeon_errata_workaround) {
 702                         if (!ndev->mw[1].bar_sz)
 703                                 return -EINVAL;
 704
 705                         ndev->limits.max_mw = SNB_ERRATA_MAX_MW;
 706                         ndev->limits.max_db_bits = SNB_MAX_DB_BITS;
 707                         ndev->reg_ofs.spad_write = ndev->mw[1].vbase +
 708                                                    SNB_SPAD_OFFSET;
 709                         ndev->reg_ofs.rdb = ndev->mw[1].vbase +
 710                                             SNB_PDOORBELL_OFFSET;
 711
 712                         /* Set the Limit register to 4k, the minimum size, to
 713                          * prevent an illegal access
 714                          */
 715                         writeq(ndev->mw[1].bar_sz + 0x1000, ndev->reg_base +
 716                                SNB_PBAR4LMT_OFFSET);
 717                         /* HW errata on the Limit registers.  They can only be
 718                          * written when the base register is 4GB aligned and
 719                          * < 32bit.  This should already be the case based on
 720                          * the driver defaults, but write the Limit registers
 721                          * first just in case.
 722                          */
 723                 } else {
 724                         ndev->limits.max_mw = SNB_MAX_MW;
 725
 726                         /* HW Errata on bit 14 of b2bdoorbell register.  Writes
 727                          * will not be mirrored to the remote system.  Shrink
 728                          * the number of bits by one, since bit 14 is the last
 729                          * bit.
 730                          */
 731                         ndev->limits.max_db_bits = SNB_MAX_DB_BITS - 1;
 732                         ndev->reg_ofs.spad_write = ndev->reg_base +
 733                                                    SNB_B2B_SPAD_OFFSET;
 734                         ndev->reg_ofs.rdb = ndev->reg_base +
 735                                             SNB_B2B_DOORBELL_OFFSET;
 736
 737                         /* Disable the Limit register, just incase it is set to
 738                          * something silly
 739                          */
 740                         writeq(0, ndev->reg_base + SNB_PBAR4LMT_OFFSET);
 741                         /* HW errata on the Limit registers.  They can only be
 742                          * written when the base register is 4GB aligned and
 743                          * < 32bit.  This should already be the case based on
 744                          * the driver defaults, but write the Limit registers
 745                          * first just in case.
 746                          */
 747                 }
 748
 749                 /* The Xeon errata workaround requires setting SBAR Base
 750                  * addresses to known values, so that the PBAR XLAT can be
 751                  * pointed at SBAR0 of the remote system.
 752                  */
 753                 if (ndev->dev_type == NTB_DEV_USD) {
 754                         writeq(SNB_MBAR23_DSD_ADDR, ndev->reg_base +
 755                                SNB_PBAR2XLAT_OFFSET);
 756                         if (xeon_errata_workaround)
 757                                 writeq(SNB_MBAR01_DSD_ADDR, ndev->reg_base +
 758                                        SNB_PBAR4XLAT_OFFSET);
 759                         else {
 760                                 writeq(SNB_MBAR45_DSD_ADDR, ndev->reg_base +
 761                                        SNB_PBAR4XLAT_OFFSET);
 762                                 /* B2B_XLAT_OFFSET is a 64bit register, but can
 763                                  * only take 32bit writes
 764                                  */
 765                                 writel(SNB_MBAR01_DSD_ADDR & 0xffffffff,
 766                                        ndev->reg_base + SNB_B2B_XLAT_OFFSETL);
 767                                 writel(SNB_MBAR01_DSD_ADDR >> 32,
 768                                        ndev->reg_base + SNB_B2B_XLAT_OFFSETU);
 769                         }
 770
 771                         writeq(SNB_MBAR01_USD_ADDR, ndev->reg_base +
 772                                SNB_SBAR0BASE_OFFSET);
 773                         writeq(SNB_MBAR23_USD_ADDR, ndev->reg_base +
 774                                SNB_SBAR2BASE_OFFSET);
 775                         writeq(SNB_MBAR45_USD_ADDR, ndev->reg_base +
 776                                SNB_SBAR4BASE_OFFSET);
 777                 } else {
 778                         writeq(SNB_MBAR23_USD_ADDR, ndev->reg_base +
 779                                SNB_PBAR2XLAT_OFFSET);
 780                         if (xeon_errata_workaround)
 781                                 writeq(SNB_MBAR01_USD_ADDR, ndev->reg_base +
 782                                        SNB_PBAR4XLAT_OFFSET);
 783                         else {
 784                                 writeq(SNB_MBAR45_USD_ADDR, ndev->reg_base +
 785                                        SNB_PBAR4XLAT_OFFSET);
 786                                 /* B2B_XLAT_OFFSET is a 64bit register, but can
 787                                  * only take 32bit writes
 788                                  */
 789                                 writel(SNB_MBAR01_USD_ADDR & 0xffffffff,
 790                                        ndev->reg_base + SNB_B2B_XLAT_OFFSETL);
 791                                 writel(SNB_MBAR01_USD_ADDR >> 32,
 792                                        ndev->reg_base + SNB_B2B_XLAT_OFFSETU);
 793                         }
 794                         writeq(SNB_MBAR01_DSD_ADDR, ndev->reg_base +
 795                                SNB_SBAR0BASE_OFFSET);
 796                         writeq(SNB_MBAR23_DSD_ADDR, ndev->reg_base +
 797                                SNB_SBAR2BASE_OFFSET);
 798                         writeq(SNB_MBAR45_DSD_ADDR, ndev->reg_base +
 799                                SNB_SBAR4BASE_OFFSET);
 800                 }
 801                 break;
 802         case NTB_CONN_RP:
 803                 dev_info(&ndev->pdev->dev, "Conn Type = RP\n");
 804                 ndev->conn_type = NTB_CONN_RP;
 805
 806                 if (xeon_errata_workaround) {
 807                         dev_err(&ndev->pdev->dev,
 808                                 "NTB-RP disabled due to hardware errata.  To disregard this warning and potentially lock-up the system, add the parameter 'xeon_errata_workaround=0'.\n");
 809                         return -EINVAL;
 810                 }
 811
 812                 /* Scratch pads need to have exclusive access from the primary
 813                  * or secondary side.  Halve the num spads so that each side can
 814                  * have an equal amount.
 815                  */
 816                 ndev->limits.max_spads = SNB_MAX_COMPAT_SPADS / 2;
 817                 ndev->limits.max_db_bits = SNB_MAX_DB_BITS;
 818                 /* Note: The SDOORBELL is the cause of the errata.  You REALLY
 819                  * don't want to touch it.
 820                  */
 821                 ndev->reg_ofs.rdb = ndev->reg_base + SNB_SDOORBELL_OFFSET;
 822                 ndev->reg_ofs.ldb = ndev->reg_base + SNB_PDOORBELL_OFFSET;
 823                 ndev->reg_ofs.ldb_mask = ndev->reg_base + SNB_PDBMSK_OFFSET;
 824                 /* Offset the start of the spads to correspond to whether it is
 825                  * primary or secondary
 826                  */
 827                 ndev->reg_ofs.spad_write = ndev->reg_base + SNB_SPAD_OFFSET +
 828                                            ndev->limits.max_spads * 4;
 829                 ndev->reg_ofs.spad_read = ndev->reg_base + SNB_SPAD_OFFSET;
 830                 ndev->reg_ofs.bar2_xlat = ndev->reg_base + SNB_SBAR2XLAT_OFFSET;
 831                 ndev->reg_ofs.bar4_xlat = ndev->reg_base + SNB_SBAR4XLAT_OFFSET;
 832                 ndev->limits.max_mw = SNB_MAX_MW;
 833                 break;
 834         case NTB_CONN_TRANSPARENT:
 835                 dev_info(&ndev->pdev->dev, "Conn Type = TRANSPARENT\n");
 836                 ndev->conn_type = NTB_CONN_TRANSPARENT;
 837                 /* Scratch pads need to have exclusive access from the primary
 838                  * or secondary side.  Halve the num spads so that each side can
 839                  * have an equal amount.
 840                  */
 841                 ndev->limits.max_spads = SNB_MAX_COMPAT_SPADS / 2;
 842                 ndev->limits.max_db_bits = SNB_MAX_DB_BITS;
 843                 ndev->reg_ofs.rdb = ndev->reg_base + SNB_PDOORBELL_OFFSET;
 844                 ndev->reg_ofs.ldb = ndev->reg_base + SNB_SDOORBELL_OFFSET;
 845                 ndev->reg_ofs.ldb_mask = ndev->reg_base + SNB_SDBMSK_OFFSET;
 846                 ndev->reg_ofs.spad_write = ndev->reg_base + SNB_SPAD_OFFSET;
 847                 /* Offset the start of the spads to correspond to whether it is
 848                  * primary or secondary
 849                  */
 850                 ndev->reg_ofs.spad_read = ndev->reg_base + SNB_SPAD_OFFSET +
 851                                           ndev->limits.max_spads * 4;
 852                 ndev->reg_ofs.bar2_xlat = ndev->reg_base + SNB_PBAR2XLAT_OFFSET;
 853                 ndev->reg_ofs.bar4_xlat = ndev->reg_base + SNB_PBAR4XLAT_OFFSET;
 854
 855                 ndev->limits.max_mw = SNB_MAX_MW;
 856                 break;
 857         default:
 858                 /* Most likely caused by the remote NTB-RP device not being
 859                  * configured
 860                  */
 861                 dev_err(&ndev->pdev->dev, "Unknown PPD %x\n", val);
 862                 return -EINVAL;
 863         }
 864
 865         ndev->reg_ofs.lnk_cntl = ndev->reg_base + SNB_NTBCNTL_OFFSET;
 866         ndev->reg_ofs.lnk_stat = ndev->reg_base + SNB_SLINK_STATUS_OFFSET;
 867         ndev->reg_ofs.spci_cmd = ndev->reg_base + SNB_PCICMD_OFFSET;
 868
 869         ndev->limits.msix_cnt = SNB_MSIX_CNT;
 870         ndev->bits_per_vector = SNB_DB_BITS_PER_VEC;
 871
 872         return 0;
 873 }
 874
 875 static int ntb_bwd_setup(struct ntb_device *ndev)
 876 {
 877         int rc;
 878         u32 val;
 879
 880         ndev->hw_type = BWD_HW;
 881
 882         rc = pci_read_config_dword(ndev->pdev, NTB_PPD_OFFSET, &val);
 883         if (rc)
 884                 return rc;
 885
 886         switch ((val & BWD_PPD_CONN_TYPE) >> 8) {
 887         case NTB_CONN_B2B:
 888                 ndev->conn_type = NTB_CONN_B2B;
 889                 break;
 890         case NTB_CONN_RP:
 891         default:
 892                 dev_err(&ndev->pdev->dev, "Unsupported NTB configuration\n");
 893                 return -EINVAL;
 894         }
 895
 896         if (val & BWD_PPD_DEV_TYPE)
 897                 ndev->dev_type = NTB_DEV_DSD;
 898         else
 899                 ndev->dev_type = NTB_DEV_USD;
 900
 901         /* Initiate PCI-E link training */
 902         rc = pci_write_config_dword(ndev->pdev, NTB_PPD_OFFSET,
 903                                     val | BWD_PPD_INIT_LINK);
 904         if (rc)
 905                 return rc;
 906
 907         ndev->reg_ofs.ldb = ndev->reg_base + BWD_PDOORBELL_OFFSET;
 908         ndev->reg_ofs.ldb_mask = ndev->reg_base + BWD_PDBMSK_OFFSET;
 909         ndev->reg_ofs.rdb = ndev->reg_base + BWD_B2B_DOORBELL_OFFSET;
 910         ndev->reg_ofs.bar2_xlat = ndev->reg_base + BWD_SBAR2XLAT_OFFSET;
 911         ndev->reg_ofs.bar4_xlat = ndev->reg_base + BWD_SBAR4XLAT_OFFSET;
 912         ndev->reg_ofs.lnk_cntl = ndev->reg_base + BWD_NTBCNTL_OFFSET;
 913         ndev->reg_ofs.lnk_stat = ndev->reg_base + BWD_LINK_STATUS_OFFSET;
 914         ndev->reg_ofs.spad_read = ndev->reg_base + BWD_SPAD_OFFSET;
 915         ndev->reg_ofs.spad_write = ndev->reg_base + BWD_B2B_SPAD_OFFSET;
 916         ndev->reg_ofs.spci_cmd = ndev->reg_base + BWD_PCICMD_OFFSET;
 917         ndev->limits.max_mw = BWD_MAX_MW;
 918         ndev->limits.max_spads = BWD_MAX_SPADS;
 919         ndev->limits.max_db_bits = BWD_MAX_DB_BITS;
 920         ndev->limits.msix_cnt = BWD_MSIX_CNT;
 921         ndev->bits_per_vector = BWD_DB_BITS_PER_VEC;
 922
 923         /* Since bwd doesn't have a link interrupt, setup a poll timer */
 924         INIT_DELAYED_WORK(&ndev->hb_timer, bwd_link_poll);
 925         INIT_DELAYED_WORK(&ndev->lr_timer, bwd_link_recovery);
 926         schedule_delayed_work(&ndev->hb_timer, NTB_HB_TIMEOUT);
 927
 928         return 0;
 929 }
 930
 931 static int ntb_device_setup(struct ntb_device *ndev)
 932 {
 933         int rc;
 934
 935         switch (ndev->pdev->device) {
 936         case PCI_DEVICE_ID_INTEL_NTB_SS_JSF:
 937         case PCI_DEVICE_ID_INTEL_NTB_SS_SNB:
 938         case PCI_DEVICE_ID_INTEL_NTB_SS_IVT:
 939         case PCI_DEVICE_ID_INTEL_NTB_SS_HSX:
 940         case PCI_DEVICE_ID_INTEL_NTB_PS_JSF:
 941         case PCI_DEVICE_ID_INTEL_NTB_PS_SNB:
 942         case PCI_DEVICE_ID_INTEL_NTB_PS_IVT:
 943         case PCI_DEVICE_ID_INTEL_NTB_PS_HSX:
 944         case PCI_DEVICE_ID_INTEL_NTB_B2B_JSF:
 945         case PCI_DEVICE_ID_INTEL_NTB_B2B_SNB:
 946         case PCI_DEVICE_ID_INTEL_NTB_B2B_IVT:
 947         case PCI_DEVICE_ID_INTEL_NTB_B2B_HSX:
 948                 rc = ntb_xeon_setup(ndev);
 949                 break;
 950         case PCI_DEVICE_ID_INTEL_NTB_B2B_BWD:
 951                 rc = ntb_bwd_setup(ndev);
 952                 break;
 953         default:
 954                 rc = -ENODEV;
 955         }
 956
 957         if (rc)
 958                 return rc;
 959
 960         dev_info(&ndev->pdev->dev, "Device Type = %s\n",
 961                  ndev->dev_type == NTB_DEV_USD ? "USD/DSP" : "DSD/USP");
 962
 963         if (ndev->conn_type == NTB_CONN_B2B)
 964                 /* Enable Bus Master and Memory Space on the secondary side */
 965                 writew(PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER,
 966                        ndev->reg_ofs.spci_cmd);
 967
 968         return 0;
 969 }
 970
 971 static void ntb_device_free(struct ntb_device *ndev)
 972 {
 973         if (ndev->hw_type == BWD_HW) {
 974                 cancel_delayed_work_sync(&ndev->hb_timer);
 975                 cancel_delayed_work_sync(&ndev->lr_timer);
 976         }
 977 }
 978
 979 static irqreturn_t bwd_callback_msix_irq(int irq, void *data)
 980 {
 981         struct ntb_db_cb *db_cb = data;
 982         struct ntb_device *ndev = db_cb->ndev;
 983         unsigned long mask;
 984
 985         dev_dbg(&ndev->pdev->dev, "MSI-X irq %d received for DB %d\n", irq,
 986                 db_cb->db_num);
 987
 988         mask = readw(ndev->reg_ofs.ldb_mask);
 989         set_bit(db_cb->db_num * ndev->bits_per_vector, &mask);
 990         writew(mask, ndev->reg_ofs.ldb_mask);
 991
 992         tasklet_schedule(&db_cb->irq_work);
 993
 994         /* No need to check for the specific HB irq, any interrupt means
 995          * we're connected.
 996          */
 997         ndev->last_ts = jiffies;
 998
 999         writeq((u64) 1 << db_cb->db_num, ndev->reg_ofs.ldb);
1000
1001         return IRQ_HANDLED;
1002 }
1003
1004 static irqreturn_t xeon_callback_msix_irq(int irq, void *data)
1005 {
1006         struct ntb_db_cb *db_cb = data;
1007         struct ntb_device *ndev = db_cb->ndev;
1008         unsigned long mask;
1009
1010         dev_dbg(&ndev->pdev->dev, "MSI-X irq %d received for DB %d\n", irq,
1011                 db_cb->db_num);
1012
1013         mask = readw(ndev->reg_ofs.ldb_mask);
1014         set_bit(db_cb->db_num * ndev->bits_per_vector, &mask);
1015         writew(mask, ndev->reg_ofs.ldb_mask);
1016
1017         tasklet_schedule(&db_cb->irq_work);
1018
1019         /* On Sandybridge, there are 16 bits in the interrupt register
1020          * but only 4 vectors.  So, 5 bits are assigned to the first 3
1021          * vectors, with the 4th having a single bit for link
1022          * interrupts.
1023          */
1024         writew(((1 << ndev->bits_per_vector) - 1) <<
1025                (db_cb->db_num * ndev->bits_per_vector), ndev->reg_ofs.ldb);
1026
1027         return IRQ_HANDLED;
1028 }
1029
1030 /* Since we do not have a HW doorbell in BWD, this is only used in JF/JT */
1031 static irqreturn_t xeon_event_msix_irq(int irq, void *dev)
1032 {
1033         struct ntb_device *ndev = dev;
1034         int rc;
1035
1036         dev_dbg(&ndev->pdev->dev, "MSI-X irq %d received for Events\n", irq);
1037
1038         rc = ntb_link_status(ndev);
1039         if (rc)
1040                 dev_err(&ndev->pdev->dev, "Error determining link status\n");
1041
1042         /* bit 15 is always the link bit */
1043         writew(1 << SNB_LINK_DB, ndev->reg_ofs.ldb);
1044
1045         return IRQ_HANDLED;
1046 }
1047
1048 static irqreturn_t ntb_interrupt(int irq, void *dev)
1049 {
1050         struct ntb_device *ndev = dev;
1051         unsigned int i = 0;
1052
1053         if (ndev->hw_type == BWD_HW) {
1054                 u64 ldb = readq(ndev->reg_ofs.ldb);
1055
1056                 dev_dbg(&ndev->pdev->dev, "irq %d - ldb = %Lx\n", irq, ldb);
1057
1058                 while (ldb) {
1059                         i = __ffs(ldb);
1060                         ldb &= ldb - 1;
1061                         bwd_callback_msix_irq(irq, &ndev->db_cb[i]);
1062                 }
1063         } else {
1064                 u16 ldb = readw(ndev->reg_ofs.ldb);
1065
1066                 dev_dbg(&ndev->pdev->dev, "irq %d - ldb = %x\n", irq, ldb);
1067
1068                 if (ldb & SNB_DB_HW_LINK) {
1069                         xeon_event_msix_irq(irq, dev);
1070                         ldb &= ~SNB_DB_HW_LINK;
1071                 }
1072
1073                 while (ldb) {
1074                         i = __ffs(ldb);
1075                         ldb &= ldb - 1;
1076                         xeon_callback_msix_irq(irq, &ndev->db_cb[i]);
1077                 }
1078         }
1079
1080         return IRQ_HANDLED;
1081 }
1082
1083 static int ntb_setup_snb_msix(struct ntb_device *ndev, int msix_entries)
1084 {
1085         struct pci_dev *pdev = ndev->pdev;
1086         struct msix_entry *msix;
1087         int rc, i;
1088
1089         if (msix_entries < ndev->limits.msix_cnt)
1090                 return -ENOSPC;
1091
1092         rc = pci_enable_msix_exact(pdev, ndev->msix_entries, msix_entries);
1093         if (rc < 0)
1094                 return rc;
1095
1096         for (i = 0; i < msix_entries; i++) {
1097                 msix = &ndev->msix_entries[i];
1098                 WARN_ON(!msix->vector);
1099
1100                 if (i == msix_entries - 1) {
1101                         rc = request_irq(msix->vector,
1102                                          xeon_event_msix_irq, 0,
1103                                          "ntb-event-msix", ndev);
1104                         if (rc)
1105                                 goto err;
1106                 } else {
1107                         rc = request_irq(msix->vector,
1108                                          xeon_callback_msix_irq, 0,
1109                                          "ntb-callback-msix",
1110                                          &ndev->db_cb[i]);
1111                         if (rc)
1112                                 goto err;
1113                 }
1114         }
1115
1116         ndev->num_msix = msix_entries;
1117         ndev->max_cbs = msix_entries - 1;
1118
1119         return 0;
1120
1121 err:
1122         while (--i >= 0) {
1123                 /* Code never reaches here for entry nr 'ndev->num_msix - 1' */
1124                 msix = &ndev->msix_entries[i];
1125                 free_irq(msix->vector, &ndev->db_cb[i]);
1126         }
1127
1128         pci_disable_msix(pdev);
1129         ndev->num_msix = 0;
1130
1131         return rc;
1132 }
1133
1134 static int ntb_setup_bwd_msix(struct ntb_device *ndev, int msix_entries)
1135 {
1136         struct pci_dev *pdev = ndev->pdev;
1137         struct msix_entry *msix;
1138         int rc, i;
1139
1140         msix_entries = pci_enable_msix_range(pdev, ndev->msix_entries,
1141                                              1, msix_entries);
1142         if (msix_entries < 0)
1143                 return msix_entries;
1144
1145         for (i = 0; i < msix_entries; i++) {
1146                 msix = &ndev->msix_entries[i];
1147                 WARN_ON(!msix->vector);
1148
1149                 rc = request_irq(msix->vector, bwd_callback_msix_irq, 0,
1150                                  "ntb-callback-msix", &ndev->db_cb[i]);
1151                 if (rc)
1152                         goto err;
1153         }
1154
1155         ndev->num_msix = msix_entries;
1156         ndev->max_cbs = msix_entries;
1157
1158         return 0;
1159
1160 err:
1161         while (--i >= 0)
1162                 free_irq(msix->vector, &ndev->db_cb[i]);
1163
1164         pci_disable_msix(pdev);
1165         ndev->num_msix = 0;
1166
1167         return rc;
1168 }
1169
1170 static int ntb_setup_msix(struct ntb_device *ndev)
1171 {
1172         struct pci_dev *pdev = ndev->pdev;
1173         int msix_entries;
1174         int rc, i;
1175
1176         msix_entries = pci_msix_vec_count(pdev);
1177         if (msix_entries < 0) {
1178                 rc = msix_entries;
1179                 goto err;
1180         } else if (msix_entries > ndev->limits.msix_cnt) {
1181                 rc = -EINVAL;
1182                 goto err;
1183         }
1184
1185         ndev->msix_entries = kmalloc(sizeof(struct msix_entry) * msix_entries,
1186                                      GFP_KERNEL);
1187         if (!ndev->msix_entries) {
1188                 rc = -ENOMEM;
1189                 goto err;
1190         }
1191
1192         for (i = 0; i < msix_entries; i++)
1193                 ndev->msix_entries[i].entry = i;
1194
1195         if (ndev->hw_type == BWD_HW)
1196                 rc = ntb_setup_bwd_msix(ndev, msix_entries);
1197         else
1198                 rc = ntb_setup_snb_msix(ndev, msix_entries);
1199         if (rc)
1200                 goto err1;
1201
1202         return 0;
1203
1204 err1:
1205         kfree(ndev->msix_entries);
1206 err:
1207         dev_err(&pdev->dev, "Error allocating MSI-X interrupt\n");
1208         return rc;
1209 }
1210
1211 static int ntb_setup_msi(struct ntb_device *ndev)
1212 {
1213         struct pci_dev *pdev = ndev->pdev;
1214         int rc;
1215
1216         rc = pci_enable_msi(pdev);
1217         if (rc)
1218                 return rc;
1219
1220         rc = request_irq(pdev->irq, ntb_interrupt, 0, "ntb-msi", ndev);
1221         if (rc) {
1222                 pci_disable_msi(pdev);
1223                 dev_err(&pdev->dev, "Error allocating MSI interrupt\n");
1224                 return rc;
1225         }
1226
1227         return 0;
1228 }
1229
1230 static int ntb_setup_intx(struct ntb_device *ndev)
1231 {
1232         struct pci_dev *pdev = ndev->pdev;
1233         int rc;
1234
1235         pci_msi_off(pdev);
1236
1237         /* Verify intx is enabled */
1238         pci_intx(pdev, 1);
1239
1240         rc = request_irq(pdev->irq, ntb_interrupt, IRQF_SHARED, "ntb-intx",
1241                          ndev);
1242         if (rc)
1243                 return rc;
1244
1245         return 0;
1246 }
1247
1248 static int ntb_setup_interrupts(struct ntb_device *ndev)
1249 {
1250         int rc;
1251
1252         /* On BWD, disable all interrupts.  On SNB, disable all but Link
1253          * Interrupt.  The rest will be unmasked as callbacks are registered.
1254          */
1255         if (ndev->hw_type == BWD_HW)
1256                 writeq(~0, ndev->reg_ofs.ldb_mask);
1257         else {
1258                 u16 var = 1 << SNB_LINK_DB;
1259                 writew(~var, ndev->reg_ofs.ldb_mask);
1260         }
1261
1262         rc = ntb_setup_msix(ndev);
1263         if (!rc)
1264                 goto done;
1265
1266         ndev->bits_per_vector = 1;
1267         ndev->max_cbs = ndev->limits.max_db_bits;
1268
1269         rc = ntb_setup_msi(ndev);
1270         if (!rc)
1271                 goto done;
1272
1273         rc = ntb_setup_intx(ndev);
1274         if (rc) {
1275                 dev_err(&ndev->pdev->dev, "no usable interrupts\n");
1276                 return rc;
1277         }
1278
1279 done:
1280         return 0;
1281 }
1282
1283 static void ntb_free_interrupts(struct ntb_device *ndev)
1284 {
1285         struct pci_dev *pdev = ndev->pdev;
1286
1287         /* mask interrupts */
1288         if (ndev->hw_type == BWD_HW)
1289                 writeq(~0, ndev->reg_ofs.ldb_mask);
1290         else
1291                 writew(~0, ndev->reg_ofs.ldb_mask);
1292
1293         if (ndev->num_msix) {
1294                 struct msix_entry *msix;
1295                 u32 i;
1296
1297                 for (i = 0; i < ndev->num_msix; i++) {
1298                         msix = &ndev->msix_entries[i];
1299                         if (ndev->hw_type != BWD_HW && i == ndev->num_msix - 1)
1300                                 free_irq(msix->vector, ndev);
1301                         else
1302                                 free_irq(msix->vector, &ndev->db_cb[i]);
1303                 }
1304                 pci_disable_msix(pdev);
1305                 kfree(ndev->msix_entries);
1306         } else {
1307                 free_irq(pdev->irq, ndev);
1308
1309                 if (pci_dev_msi_enabled(pdev))
1310                         pci_disable_msi(pdev);
1311         }
1312 }
1313
1314 static int ntb_create_callbacks(struct ntb_device *ndev)
1315 {
1316         int i;
1317
1318         /* Chicken-egg issue.  We won't know how many callbacks are necessary
1319          * until we see how many MSI-X vectors we get, but these pointers need
1320          * to be passed into the MSI-X register function.  So, we allocate the
1321          * max, knowing that they might not all be used, to work around this.
1322          */
1323         ndev->db_cb = kcalloc(ndev->limits.max_db_bits,
1324                               sizeof(struct ntb_db_cb),
1325                               GFP_KERNEL);
1326         if (!ndev->db_cb)
1327                 return -ENOMEM;
1328
1329         for (i = 0; i < ndev->limits.max_db_bits; i++) {
1330                 ndev->db_cb[i].db_num = i;
1331                 ndev->db_cb[i].ndev = ndev;
1332         }
1333
1334         return 0;
1335 }
1336
1337 static void ntb_free_callbacks(struct ntb_device *ndev)
1338 {
1339         int i;
1340
1341         for (i = 0; i < ndev->limits.max_db_bits; i++)
1342                 ntb_unregister_db_callback(ndev, i);
1343
1344         kfree(ndev->db_cb);
1345 }
1346
1347 static void ntb_setup_debugfs(struct ntb_device *ndev)
1348 {
1349         if (!debugfs_initialized())
1350                 return;
1351
1352         if (!debugfs_dir)
1353                 debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
1354
1355         ndev->debugfs_dir = debugfs_create_dir(pci_name(ndev->pdev),
1356                                                debugfs_dir);
1357 }
1358
1359 static void ntb_free_debugfs(struct ntb_device *ndev)
1360 {
1361         debugfs_remove_recursive(ndev->debugfs_dir);
1362
1363         if (debugfs_dir && simple_empty(debugfs_dir)) {
1364                 debugfs_remove_recursive(debugfs_dir);
1365                 debugfs_dir = NULL;
1366         }
1367 }
1368
1369 static void ntb_hw_link_up(struct ntb_device *ndev)
1370 {
1371         if (ndev->conn_type == NTB_CONN_TRANSPARENT)
1372                 ntb_link_event(ndev, NTB_LINK_UP);
1373         else {
1374                 u32 ntb_cntl;
1375
1376                 /* Let's bring the NTB link up */
1377                 ntb_cntl = readl(ndev->reg_ofs.lnk_cntl);
1378                 ntb_cntl &= ~(NTB_CNTL_LINK_DISABLE | NTB_CNTL_CFG_LOCK);
1379                 ntb_cntl |= NTB_CNTL_P2S_BAR23_SNOOP | NTB_CNTL_S2P_BAR23_SNOOP;
1380                 ntb_cntl |= NTB_CNTL_P2S_BAR45_SNOOP | NTB_CNTL_S2P_BAR45_SNOOP;
1381                 writel(ntb_cntl, ndev->reg_ofs.lnk_cntl);
1382         }
1383 }
1384
1385 static void ntb_hw_link_down(struct ntb_device *ndev)
1386 {
1387         u32 ntb_cntl;
1388
1389         if (ndev->conn_type == NTB_CONN_TRANSPARENT) {
1390                 ntb_link_event(ndev, NTB_LINK_DOWN);
1391                 return;
1392         }
1393
1394         /* Bring NTB link down */
1395         ntb_cntl = readl(ndev->reg_ofs.lnk_cntl);
1396         ntb_cntl &= ~(NTB_CNTL_P2S_BAR23_SNOOP | NTB_CNTL_S2P_BAR23_SNOOP);
1397         ntb_cntl &= ~(NTB_CNTL_P2S_BAR45_SNOOP | NTB_CNTL_S2P_BAR45_SNOOP);
1398         ntb_cntl |= NTB_CNTL_LINK_DISABLE | NTB_CNTL_CFG_LOCK;
1399         writel(ntb_cntl, ndev->reg_ofs.lnk_cntl);
1400 }
1401
1402 static int ntb_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
1403 {
1404         struct ntb_device *ndev;
1405         int rc, i;
1406
1407         ndev = kzalloc(sizeof(struct ntb_device), GFP_KERNEL);
1408         if (!ndev)
1409                 return -ENOMEM;
1410
1411         ndev->pdev = pdev;
1412         ndev->link_status = NTB_LINK_DOWN;
1413         pci_set_drvdata(pdev, ndev);
1414         ntb_setup_debugfs(ndev);
1415
1416         rc = pci_enable_device(pdev);
1417         if (rc)
1418                 goto err;
1419
1420         pci_set_master(ndev->pdev);
1421
1422         rc = pci_request_selected_regions(pdev, NTB_BAR_MASK, KBUILD_MODNAME);
1423         if (rc)
1424                 goto err1;
1425
1426         ndev->reg_base = pci_ioremap_bar(pdev, NTB_BAR_MMIO);
1427         if (!ndev->reg_base) {
1428                 dev_warn(&pdev->dev, "Cannot remap BAR 0\n");
1429                 rc = -EIO;
1430                 goto err2;
1431         }
1432
1433         for (i = 0; i < NTB_MAX_NUM_MW; i++) {
1434                 ndev->mw[i].bar_sz = pci_resource_len(pdev, MW_TO_BAR(i));
1435                 ndev->mw[i].vbase =
1436                     ioremap_wc(pci_resource_start(pdev, MW_TO_BAR(i)),
1437                                ndev->mw[i].bar_sz);
1438                 dev_info(&pdev->dev, "MW %d size %llu\n", i,
1439                          (unsigned long long) ndev->mw[i].bar_sz);
1440                 if (!ndev->mw[i].vbase) {
1441                         dev_warn(&pdev->dev, "Cannot remap BAR %d\n",
1442                                  MW_TO_BAR(i));
1443                         rc = -EIO;
1444                         goto err3;
1445                 }
1446         }
1447
1448         rc = pci_set_dma_mask(pdev, DMA_BIT_MASK(64));
1449         if (rc) {
1450                 rc = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
1451                 if (rc)
1452                         goto err3;
1453
1454                 dev_warn(&pdev->dev, "Cannot DMA highmem\n");
1455         }
1456
1457         rc = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64));
1458         if (rc) {
1459                 rc = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));
1460                 if (rc)
1461                         goto err3;
1462
1463                 dev_warn(&pdev->dev, "Cannot DMA consistent highmem\n");
1464         }
1465
1466         rc = ntb_device_setup(ndev);
1467         if (rc)
1468                 goto err3;
1469
1470         rc = ntb_create_callbacks(ndev);
1471         if (rc)
1472                 goto err4;
1473
1474         rc = ntb_setup_interrupts(ndev);
1475         if (rc)
1476                 goto err5;
1477
1478         /* The scratchpad registers keep the values between rmmod/insmod,
1479          * blast them now
1480          */
1481         for (i = 0; i < ndev->limits.max_spads; i++) {
1482                 ntb_write_local_spad(ndev, i, 0);
1483                 ntb_write_remote_spad(ndev, i, 0);
1484         }
1485
1486         rc = ntb_transport_init(pdev);
1487         if (rc)
1488                 goto err6;
1489
1490         ntb_hw_link_up(ndev);
1491
1492         return 0;
1493
1494 err6:
1495         ntb_free_interrupts(ndev);
1496 err5:
1497         ntb_free_callbacks(ndev);
1498 err4:
1499         ntb_device_free(ndev);
1500 err3:
1501         for (i--; i >= 0; i--)
1502                 iounmap(ndev->mw[i].vbase);
1503         iounmap(ndev->reg_base);
1504 err2:
1505         pci_release_selected_regions(pdev, NTB_BAR_MASK);
1506 err1:
1507         pci_disable_device(pdev);
1508 err:
1509         ntb_free_debugfs(ndev);
1510         kfree(ndev);
1511
1512         dev_err(&pdev->dev, "Error loading %s module\n", KBUILD_MODNAME);
1513         return rc;
1514 }
1515
1516 static void ntb_pci_remove(struct pci_dev *pdev)
1517 {
1518         struct ntb_device *ndev = pci_get_drvdata(pdev);
1519         int i;
1520
1521         ntb_hw_link_down(ndev);
1522
1523         ntb_transport_free(ndev->ntb_transport);
1524
1525         ntb_free_interrupts(ndev);
1526         ntb_free_callbacks(ndev);
1527         ntb_device_free(ndev);
1528
1529         for (i = 0; i < NTB_MAX_NUM_MW; i++)
1530                 iounmap(ndev->mw[i].vbase);
1531
1532         iounmap(ndev->reg_base);
1533         pci_release_selected_regions(pdev, NTB_BAR_MASK);
1534         pci_disable_device(pdev);
1535         ntb_free_debugfs(ndev);
1536         kfree(ndev);
1537 }
1538
1539 static struct pci_driver ntb_pci_driver = {
1540         .name = KBUILD_MODNAME,
1541         .id_table = ntb_pci_tbl,
1542         .probe = ntb_pci_probe,
1543         .remove = ntb_pci_remove,
1544 };
1545 module_pci_driver(ntb_pci_driver);