Version:  2.0.40 2.2.26 2.4.37 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9

Linux/drivers/scsi/vmw_pvscsi.c

  1 /*
  2  * Linux driver for VMware's para-virtualized SCSI HBA.
  3  *
  4  * Copyright (C) 2008-2014, VMware, Inc. All Rights Reserved.
  5  *
  6  * This program is free software; you can redistribute it and/or modify it
  7  * under the terms of the GNU General Public License as published by the
  8  * Free Software Foundation; version 2 of the License and no later version.
  9  *
 10  * This program is distributed in the hope that it will be useful, but
 11  * WITHOUT ANY WARRANTY; without even the implied warranty of
 12  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 13  * NON INFRINGEMENT.  See the GNU General Public License for more
 14  * details.
 15  *
 16  * You should have received a copy of the GNU General Public License
 17  * along with this program; if not, write to the Free Software
 18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 19  *
 20  * Maintained by: Jim Gill <jgill@vmware.com>
 21  *
 22  */
 23 
 24 #include <linux/kernel.h>
 25 #include <linux/module.h>
 26 #include <linux/interrupt.h>
 27 #include <linux/slab.h>
 28 #include <linux/workqueue.h>
 29 #include <linux/pci.h>
 30 
 31 #include <scsi/scsi.h>
 32 #include <scsi/scsi_host.h>
 33 #include <scsi/scsi_cmnd.h>
 34 #include <scsi/scsi_device.h>
 35 #include <scsi/scsi_tcq.h>
 36 
 37 #include "vmw_pvscsi.h"
 38 
 39 #define PVSCSI_LINUX_DRIVER_DESC "VMware PVSCSI driver"
 40 
 41 MODULE_DESCRIPTION(PVSCSI_LINUX_DRIVER_DESC);
 42 MODULE_AUTHOR("VMware, Inc.");
 43 MODULE_LICENSE("GPL");
 44 MODULE_VERSION(PVSCSI_DRIVER_VERSION_STRING);
 45 
 46 #define PVSCSI_DEFAULT_NUM_PAGES_PER_RING       8
 47 #define PVSCSI_DEFAULT_NUM_PAGES_MSG_RING       1
 48 #define PVSCSI_DEFAULT_QUEUE_DEPTH              254
 49 #define SGL_SIZE                                PAGE_SIZE
 50 
 51 struct pvscsi_sg_list {
 52         struct PVSCSISGElement sge[PVSCSI_MAX_NUM_SG_ENTRIES_PER_SEGMENT];
 53 };
 54 
 55 struct pvscsi_ctx {
 56         /*
 57          * The index of the context in cmd_map serves as the context ID for a
 58          * 1-to-1 mapping completions back to requests.
 59          */
 60         struct scsi_cmnd        *cmd;
 61         struct pvscsi_sg_list   *sgl;
 62         struct list_head        list;
 63         dma_addr_t              dataPA;
 64         dma_addr_t              sensePA;
 65         dma_addr_t              sglPA;
 66         struct completion       *abort_cmp;
 67 };
 68 
 69 struct pvscsi_adapter {
 70         char                            *mmioBase;
 71         unsigned int                    irq;
 72         u8                              rev;
 73         bool                            use_msi;
 74         bool                            use_msix;
 75         bool                            use_msg;
 76         bool                            use_req_threshold;
 77 
 78         spinlock_t                      hw_lock;
 79 
 80         struct workqueue_struct         *workqueue;
 81         struct work_struct              work;
 82 
 83         struct PVSCSIRingReqDesc        *req_ring;
 84         unsigned                        req_pages;
 85         unsigned                        req_depth;
 86         dma_addr_t                      reqRingPA;
 87 
 88         struct PVSCSIRingCmpDesc        *cmp_ring;
 89         unsigned                        cmp_pages;
 90         dma_addr_t                      cmpRingPA;
 91 
 92         struct PVSCSIRingMsgDesc        *msg_ring;
 93         unsigned                        msg_pages;
 94         dma_addr_t                      msgRingPA;
 95 
 96         struct PVSCSIRingsState         *rings_state;
 97         dma_addr_t                      ringStatePA;
 98 
 99         struct pci_dev                  *dev;
100         struct Scsi_Host                *host;
101 
102         struct list_head                cmd_pool;
103         struct pvscsi_ctx               *cmd_map;
104 };
105 
106 
107 /* Command line parameters */
108 static int pvscsi_ring_pages;
109 static int pvscsi_msg_ring_pages = PVSCSI_DEFAULT_NUM_PAGES_MSG_RING;
110 static int pvscsi_cmd_per_lun    = PVSCSI_DEFAULT_QUEUE_DEPTH;
111 static bool pvscsi_disable_msi;
112 static bool pvscsi_disable_msix;
113 static bool pvscsi_use_msg       = true;
114 static bool pvscsi_use_req_threshold = true;
115 
116 #define PVSCSI_RW (S_IRUSR | S_IWUSR)
117 
118 module_param_named(ring_pages, pvscsi_ring_pages, int, PVSCSI_RW);
119 MODULE_PARM_DESC(ring_pages, "Number of pages per req/cmp ring - (default="
120                  __stringify(PVSCSI_DEFAULT_NUM_PAGES_PER_RING)
121                  "[up to 16 targets],"
122                  __stringify(PVSCSI_SETUP_RINGS_MAX_NUM_PAGES)
123                  "[for 16+ targets])");
124 
125 module_param_named(msg_ring_pages, pvscsi_msg_ring_pages, int, PVSCSI_RW);
126 MODULE_PARM_DESC(msg_ring_pages, "Number of pages for the msg ring - (default="
127                  __stringify(PVSCSI_DEFAULT_NUM_PAGES_MSG_RING) ")");
128 
129 module_param_named(cmd_per_lun, pvscsi_cmd_per_lun, int, PVSCSI_RW);
130 MODULE_PARM_DESC(cmd_per_lun, "Maximum commands per lun - (default="
131                  __stringify(PVSCSI_DEFAULT_QUEUE_DEPTH) ")");
132 
133 module_param_named(disable_msi, pvscsi_disable_msi, bool, PVSCSI_RW);
134 MODULE_PARM_DESC(disable_msi, "Disable MSI use in driver - (default=0)");
135 
136 module_param_named(disable_msix, pvscsi_disable_msix, bool, PVSCSI_RW);
137 MODULE_PARM_DESC(disable_msix, "Disable MSI-X use in driver - (default=0)");
138 
139 module_param_named(use_msg, pvscsi_use_msg, bool, PVSCSI_RW);
140 MODULE_PARM_DESC(use_msg, "Use msg ring when available - (default=1)");
141 
142 module_param_named(use_req_threshold, pvscsi_use_req_threshold,
143                    bool, PVSCSI_RW);
144 MODULE_PARM_DESC(use_req_threshold, "Use driver-based request coalescing if configured - (default=1)");
145 
146 static const struct pci_device_id pvscsi_pci_tbl[] = {
147         { PCI_VDEVICE(VMWARE, PCI_DEVICE_ID_VMWARE_PVSCSI) },
148         { 0 }
149 };
150 
151 MODULE_DEVICE_TABLE(pci, pvscsi_pci_tbl);
152 
153 static struct device *
154 pvscsi_dev(const struct pvscsi_adapter *adapter)
155 {
156         return &(adapter->dev->dev);
157 }
158 
159 static struct pvscsi_ctx *
160 pvscsi_find_context(const struct pvscsi_adapter *adapter, struct scsi_cmnd *cmd)
161 {
162         struct pvscsi_ctx *ctx, *end;
163 
164         end = &adapter->cmd_map[adapter->req_depth];
165         for (ctx = adapter->cmd_map; ctx < end; ctx++)
166                 if (ctx->cmd == cmd)
167                         return ctx;
168 
169         return NULL;
170 }
171 
172 static struct pvscsi_ctx *
173 pvscsi_acquire_context(struct pvscsi_adapter *adapter, struct scsi_cmnd *cmd)
174 {
175         struct pvscsi_ctx *ctx;
176 
177         if (list_empty(&adapter->cmd_pool))
178                 return NULL;
179 
180         ctx = list_first_entry(&adapter->cmd_pool, struct pvscsi_ctx, list);
181         ctx->cmd = cmd;
182         list_del(&ctx->list);
183 
184         return ctx;
185 }
186 
187 static void pvscsi_release_context(struct pvscsi_adapter *adapter,
188                                    struct pvscsi_ctx *ctx)
189 {
190         ctx->cmd = NULL;
191         ctx->abort_cmp = NULL;
192         list_add(&ctx->list, &adapter->cmd_pool);
193 }
194 
195 /*
196  * Map a pvscsi_ctx struct to a context ID field value; we map to a simple
197  * non-zero integer. ctx always points to an entry in cmd_map array, hence
198  * the return value is always >=1.
199  */
200 static u64 pvscsi_map_context(const struct pvscsi_adapter *adapter,
201                               const struct pvscsi_ctx *ctx)
202 {
203         return ctx - adapter->cmd_map + 1;
204 }
205 
206 static struct pvscsi_ctx *
207 pvscsi_get_context(const struct pvscsi_adapter *adapter, u64 context)
208 {
209         return &adapter->cmd_map[context - 1];
210 }
211 
212 static void pvscsi_reg_write(const struct pvscsi_adapter *adapter,
213                              u32 offset, u32 val)
214 {
215         writel(val, adapter->mmioBase + offset);
216 }
217 
218 static u32 pvscsi_reg_read(const struct pvscsi_adapter *adapter, u32 offset)
219 {
220         return readl(adapter->mmioBase + offset);
221 }
222 
223 static u32 pvscsi_read_intr_status(const struct pvscsi_adapter *adapter)
224 {
225         return pvscsi_reg_read(adapter, PVSCSI_REG_OFFSET_INTR_STATUS);
226 }
227 
228 static void pvscsi_write_intr_status(const struct pvscsi_adapter *adapter,
229                                      u32 val)
230 {
231         pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_INTR_STATUS, val);
232 }
233 
234 static void pvscsi_unmask_intr(const struct pvscsi_adapter *adapter)
235 {
236         u32 intr_bits;
237 
238         intr_bits = PVSCSI_INTR_CMPL_MASK;
239         if (adapter->use_msg)
240                 intr_bits |= PVSCSI_INTR_MSG_MASK;
241 
242         pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_INTR_MASK, intr_bits);
243 }
244 
245 static void pvscsi_mask_intr(const struct pvscsi_adapter *adapter)
246 {
247         pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_INTR_MASK, 0);
248 }
249 
250 static void pvscsi_write_cmd_desc(const struct pvscsi_adapter *adapter,
251                                   u32 cmd, const void *desc, size_t len)
252 {
253         const u32 *ptr = desc;
254         size_t i;
255 
256         len /= sizeof(*ptr);
257         pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_COMMAND, cmd);
258         for (i = 0; i < len; i++)
259                 pvscsi_reg_write(adapter,
260                                  PVSCSI_REG_OFFSET_COMMAND_DATA, ptr[i]);
261 }
262 
263 static void pvscsi_abort_cmd(const struct pvscsi_adapter *adapter,
264                              const struct pvscsi_ctx *ctx)
265 {
266         struct PVSCSICmdDescAbortCmd cmd = { 0 };
267 
268         cmd.target = ctx->cmd->device->id;
269         cmd.context = pvscsi_map_context(adapter, ctx);
270 
271         pvscsi_write_cmd_desc(adapter, PVSCSI_CMD_ABORT_CMD, &cmd, sizeof(cmd));
272 }
273 
274 static void pvscsi_kick_rw_io(const struct pvscsi_adapter *adapter)
275 {
276         pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_KICK_RW_IO, 0);
277 }
278 
279 static void pvscsi_process_request_ring(const struct pvscsi_adapter *adapter)
280 {
281         pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_KICK_NON_RW_IO, 0);
282 }
283 
284 static int scsi_is_rw(unsigned char op)
285 {
286         return op == READ_6  || op == WRITE_6 ||
287                op == READ_10 || op == WRITE_10 ||
288                op == READ_12 || op == WRITE_12 ||
289                op == READ_16 || op == WRITE_16;
290 }
291 
292 static void pvscsi_kick_io(const struct pvscsi_adapter *adapter,
293                            unsigned char op)
294 {
295         if (scsi_is_rw(op)) {
296                 struct PVSCSIRingsState *s = adapter->rings_state;
297 
298                 if (!adapter->use_req_threshold ||
299                     s->reqProdIdx - s->reqConsIdx >= s->reqCallThreshold)
300                         pvscsi_kick_rw_io(adapter);
301         } else {
302                 pvscsi_process_request_ring(adapter);
303         }
304 }
305 
306 static void ll_adapter_reset(const struct pvscsi_adapter *adapter)
307 {
308         dev_dbg(pvscsi_dev(adapter), "Adapter Reset on %p\n", adapter);
309 
310         pvscsi_write_cmd_desc(adapter, PVSCSI_CMD_ADAPTER_RESET, NULL, 0);
311 }
312 
313 static void ll_bus_reset(const struct pvscsi_adapter *adapter)
314 {
315         dev_dbg(pvscsi_dev(adapter), "Resetting bus on %p\n", adapter);
316 
317         pvscsi_write_cmd_desc(adapter, PVSCSI_CMD_RESET_BUS, NULL, 0);
318 }
319 
320 static void ll_device_reset(const struct pvscsi_adapter *adapter, u32 target)
321 {
322         struct PVSCSICmdDescResetDevice cmd = { 0 };
323 
324         dev_dbg(pvscsi_dev(adapter), "Resetting device: target=%u\n", target);
325 
326         cmd.target = target;
327 
328         pvscsi_write_cmd_desc(adapter, PVSCSI_CMD_RESET_DEVICE,
329                               &cmd, sizeof(cmd));
330 }
331 
332 static void pvscsi_create_sg(struct pvscsi_ctx *ctx,
333                              struct scatterlist *sg, unsigned count)
334 {
335         unsigned i;
336         struct PVSCSISGElement *sge;
337 
338         BUG_ON(count > PVSCSI_MAX_NUM_SG_ENTRIES_PER_SEGMENT);
339 
340         sge = &ctx->sgl->sge[0];
341         for (i = 0; i < count; i++, sg++) {
342                 sge[i].addr   = sg_dma_address(sg);
343                 sge[i].length = sg_dma_len(sg);
344                 sge[i].flags  = 0;
345         }
346 }
347 
348 /*
349  * Map all data buffers for a command into PCI space and
350  * setup the scatter/gather list if needed.
351  */
352 static int pvscsi_map_buffers(struct pvscsi_adapter *adapter,
353                               struct pvscsi_ctx *ctx, struct scsi_cmnd *cmd,
354                               struct PVSCSIRingReqDesc *e)
355 {
356         unsigned count;
357         unsigned bufflen = scsi_bufflen(cmd);
358         struct scatterlist *sg;
359 
360         e->dataLen = bufflen;
361         e->dataAddr = 0;
362         if (bufflen == 0)
363                 return 0;
364 
365         sg = scsi_sglist(cmd);
366         count = scsi_sg_count(cmd);
367         if (count != 0) {
368                 int segs = scsi_dma_map(cmd);
369 
370                 if (segs == -ENOMEM) {
371                         scmd_printk(KERN_ERR, cmd,
372                                     "vmw_pvscsi: Failed to map cmd sglist for DMA.\n");
373                         return -ENOMEM;
374                 } else if (segs > 1) {
375                         pvscsi_create_sg(ctx, sg, segs);
376 
377                         e->flags |= PVSCSI_FLAG_CMD_WITH_SG_LIST;
378                         ctx->sglPA = pci_map_single(adapter->dev, ctx->sgl,
379                                                     SGL_SIZE, PCI_DMA_TODEVICE);
380                         if (pci_dma_mapping_error(adapter->dev, ctx->sglPA)) {
381                                 scmd_printk(KERN_ERR, cmd,
382                                             "vmw_pvscsi: Failed to map ctx sglist for DMA.\n");
383                                 scsi_dma_unmap(cmd);
384                                 ctx->sglPA = 0;
385                                 return -ENOMEM;
386                         }
387                         e->dataAddr = ctx->sglPA;
388                 } else
389                         e->dataAddr = sg_dma_address(sg);
390         } else {
391                 /*
392                  * In case there is no S/G list, scsi_sglist points
393                  * directly to the buffer.
394                  */
395                 ctx->dataPA = pci_map_single(adapter->dev, sg, bufflen,
396                                              cmd->sc_data_direction);
397                 if (pci_dma_mapping_error(adapter->dev, ctx->dataPA)) {
398                         scmd_printk(KERN_ERR, cmd,
399                                     "vmw_pvscsi: Failed to map direct data buffer for DMA.\n");
400                         return -ENOMEM;
401                 }
402                 e->dataAddr = ctx->dataPA;
403         }
404 
405         return 0;
406 }
407 
408 static void pvscsi_unmap_buffers(const struct pvscsi_adapter *adapter,
409                                  struct pvscsi_ctx *ctx)
410 {
411         struct scsi_cmnd *cmd;
412         unsigned bufflen;
413 
414         cmd = ctx->cmd;
415         bufflen = scsi_bufflen(cmd);
416 
417         if (bufflen != 0) {
418                 unsigned count = scsi_sg_count(cmd);
419 
420                 if (count != 0) {
421                         scsi_dma_unmap(cmd);
422                         if (ctx->sglPA) {
423                                 pci_unmap_single(adapter->dev, ctx->sglPA,
424                                                  SGL_SIZE, PCI_DMA_TODEVICE);
425                                 ctx->sglPA = 0;
426                         }
427                 } else
428                         pci_unmap_single(adapter->dev, ctx->dataPA, bufflen,
429                                          cmd->sc_data_direction);
430         }
431         if (cmd->sense_buffer)
432                 pci_unmap_single(adapter->dev, ctx->sensePA,
433                                  SCSI_SENSE_BUFFERSIZE, PCI_DMA_FROMDEVICE);
434 }
435 
436 static int pvscsi_allocate_rings(struct pvscsi_adapter *adapter)
437 {
438         adapter->rings_state = pci_alloc_consistent(adapter->dev, PAGE_SIZE,
439                                                     &adapter->ringStatePA);
440         if (!adapter->rings_state)
441                 return -ENOMEM;
442 
443         adapter->req_pages = min(PVSCSI_MAX_NUM_PAGES_REQ_RING,
444                                  pvscsi_ring_pages);
445         adapter->req_depth = adapter->req_pages
446                                         * PVSCSI_MAX_NUM_REQ_ENTRIES_PER_PAGE;
447         adapter->req_ring = pci_alloc_consistent(adapter->dev,
448                                                  adapter->req_pages * PAGE_SIZE,
449                                                  &adapter->reqRingPA);
450         if (!adapter->req_ring)
451                 return -ENOMEM;
452 
453         adapter->cmp_pages = min(PVSCSI_MAX_NUM_PAGES_CMP_RING,
454                                  pvscsi_ring_pages);
455         adapter->cmp_ring = pci_alloc_consistent(adapter->dev,
456                                                  adapter->cmp_pages * PAGE_SIZE,
457                                                  &adapter->cmpRingPA);
458         if (!adapter->cmp_ring)
459                 return -ENOMEM;
460 
461         BUG_ON(!IS_ALIGNED(adapter->ringStatePA, PAGE_SIZE));
462         BUG_ON(!IS_ALIGNED(adapter->reqRingPA, PAGE_SIZE));
463         BUG_ON(!IS_ALIGNED(adapter->cmpRingPA, PAGE_SIZE));
464 
465         if (!adapter->use_msg)
466                 return 0;
467 
468         adapter->msg_pages = min(PVSCSI_MAX_NUM_PAGES_MSG_RING,
469                                  pvscsi_msg_ring_pages);
470         adapter->msg_ring = pci_alloc_consistent(adapter->dev,
471                                                  adapter->msg_pages * PAGE_SIZE,
472                                                  &adapter->msgRingPA);
473         if (!adapter->msg_ring)
474                 return -ENOMEM;
475         BUG_ON(!IS_ALIGNED(adapter->msgRingPA, PAGE_SIZE));
476 
477         return 0;
478 }
479 
480 static void pvscsi_setup_all_rings(const struct pvscsi_adapter *adapter)
481 {
482         struct PVSCSICmdDescSetupRings cmd = { 0 };
483         dma_addr_t base;
484         unsigned i;
485 
486         cmd.ringsStatePPN   = adapter->ringStatePA >> PAGE_SHIFT;
487         cmd.reqRingNumPages = adapter->req_pages;
488         cmd.cmpRingNumPages = adapter->cmp_pages;
489 
490         base = adapter->reqRingPA;
491         for (i = 0; i < adapter->req_pages; i++) {
492                 cmd.reqRingPPNs[i] = base >> PAGE_SHIFT;
493                 base += PAGE_SIZE;
494         }
495 
496         base = adapter->cmpRingPA;
497         for (i = 0; i < adapter->cmp_pages; i++) {
498                 cmd.cmpRingPPNs[i] = base >> PAGE_SHIFT;
499                 base += PAGE_SIZE;
500         }
501 
502         memset(adapter->rings_state, 0, PAGE_SIZE);
503         memset(adapter->req_ring, 0, adapter->req_pages * PAGE_SIZE);
504         memset(adapter->cmp_ring, 0, adapter->cmp_pages * PAGE_SIZE);
505 
506         pvscsi_write_cmd_desc(adapter, PVSCSI_CMD_SETUP_RINGS,
507                               &cmd, sizeof(cmd));
508 
509         if (adapter->use_msg) {
510                 struct PVSCSICmdDescSetupMsgRing cmd_msg = { 0 };
511 
512                 cmd_msg.numPages = adapter->msg_pages;
513 
514                 base = adapter->msgRingPA;
515                 for (i = 0; i < adapter->msg_pages; i++) {
516                         cmd_msg.ringPPNs[i] = base >> PAGE_SHIFT;
517                         base += PAGE_SIZE;
518                 }
519                 memset(adapter->msg_ring, 0, adapter->msg_pages * PAGE_SIZE);
520 
521                 pvscsi_write_cmd_desc(adapter, PVSCSI_CMD_SETUP_MSG_RING,
522                                       &cmd_msg, sizeof(cmd_msg));
523         }
524 }
525 
526 static int pvscsi_change_queue_depth(struct scsi_device *sdev, int qdepth)
527 {
528         if (!sdev->tagged_supported)
529                 qdepth = 1;
530         return scsi_change_queue_depth(sdev, qdepth);
531 }
532 
533 /*
534  * Pull a completion descriptor off and pass the completion back
535  * to the SCSI mid layer.
536  */
537 static void pvscsi_complete_request(struct pvscsi_adapter *adapter,
538                                     const struct PVSCSIRingCmpDesc *e)
539 {
540         struct pvscsi_ctx *ctx;
541         struct scsi_cmnd *cmd;
542         struct completion *abort_cmp;
543         u32 btstat = e->hostStatus;
544         u32 sdstat = e->scsiStatus;
545 
546         ctx = pvscsi_get_context(adapter, e->context);
547         cmd = ctx->cmd;
548         abort_cmp = ctx->abort_cmp;
549         pvscsi_unmap_buffers(adapter, ctx);
550         pvscsi_release_context(adapter, ctx);
551         if (abort_cmp) {
552                 /*
553                  * The command was requested to be aborted. Just signal that
554                  * the request completed and swallow the actual cmd completion
555                  * here. The abort handler will post a completion for this
556                  * command indicating that it got successfully aborted.
557                  */
558                 complete(abort_cmp);
559                 return;
560         }
561 
562         cmd->result = 0;
563         if (sdstat != SAM_STAT_GOOD &&
564             (btstat == BTSTAT_SUCCESS ||
565              btstat == BTSTAT_LINKED_COMMAND_COMPLETED ||
566              btstat == BTSTAT_LINKED_COMMAND_COMPLETED_WITH_FLAG)) {
567                 cmd->result = (DID_OK << 16) | sdstat;
568                 if (sdstat == SAM_STAT_CHECK_CONDITION && cmd->sense_buffer)
569                         cmd->result |= (DRIVER_SENSE << 24);
570         } else
571                 switch (btstat) {
572                 case BTSTAT_SUCCESS:
573                 case BTSTAT_LINKED_COMMAND_COMPLETED:
574                 case BTSTAT_LINKED_COMMAND_COMPLETED_WITH_FLAG:
575                         /* If everything went fine, let's move on..  */
576                         cmd->result = (DID_OK << 16);
577                         break;
578 
579                 case BTSTAT_DATARUN:
580                 case BTSTAT_DATA_UNDERRUN:
581                         /* Report residual data in underruns */
582                         scsi_set_resid(cmd, scsi_bufflen(cmd) - e->dataLen);
583                         cmd->result = (DID_ERROR << 16);
584                         break;
585 
586                 case BTSTAT_SELTIMEO:
587                         /* Our emulation returns this for non-connected devs */
588                         cmd->result = (DID_BAD_TARGET << 16);
589                         break;
590 
591                 case BTSTAT_LUNMISMATCH:
592                 case BTSTAT_TAGREJECT:
593                 case BTSTAT_BADMSG:
594                         cmd->result = (DRIVER_INVALID << 24);
595                         /* fall through */
596 
597                 case BTSTAT_HAHARDWARE:
598                 case BTSTAT_INVPHASE:
599                 case BTSTAT_HATIMEOUT:
600                 case BTSTAT_NORESPONSE:
601                 case BTSTAT_DISCONNECT:
602                 case BTSTAT_HASOFTWARE:
603                 case BTSTAT_BUSFREE:
604                 case BTSTAT_SENSFAILED:
605                         cmd->result |= (DID_ERROR << 16);
606                         break;
607 
608                 case BTSTAT_SENTRST:
609                 case BTSTAT_RECVRST:
610                 case BTSTAT_BUSRESET:
611                         cmd->result = (DID_RESET << 16);
612                         break;
613 
614                 case BTSTAT_ABORTQUEUE:
615                         cmd->result = (DID_ABORT << 16);
616                         break;
617 
618                 case BTSTAT_SCSIPARITY:
619                         cmd->result = (DID_PARITY << 16);
620                         break;
621 
622                 default:
623                         cmd->result = (DID_ERROR << 16);
624                         scmd_printk(KERN_DEBUG, cmd,
625                                     "Unknown completion status: 0x%x\n",
626                                     btstat);
627         }
628 
629         dev_dbg(&cmd->device->sdev_gendev,
630                 "cmd=%p %x ctx=%p result=0x%x status=0x%x,%x\n",
631                 cmd, cmd->cmnd[0], ctx, cmd->result, btstat, sdstat);
632 
633         cmd->scsi_done(cmd);
634 }
635 
636 /*
637  * barrier usage : Since the PVSCSI device is emulated, there could be cases
638  * where we may want to serialize some accesses between the driver and the
639  * emulation layer. We use compiler barriers instead of the more expensive
640  * memory barriers because PVSCSI is only supported on X86 which has strong
641  * memory access ordering.
642  */
643 static void pvscsi_process_completion_ring(struct pvscsi_adapter *adapter)
644 {
645         struct PVSCSIRingsState *s = adapter->rings_state;
646         struct PVSCSIRingCmpDesc *ring = adapter->cmp_ring;
647         u32 cmp_entries = s->cmpNumEntriesLog2;
648 
649         while (s->cmpConsIdx != s->cmpProdIdx) {
650                 struct PVSCSIRingCmpDesc *e = ring + (s->cmpConsIdx &
651                                                       MASK(cmp_entries));
652                 /*
653                  * This barrier() ensures that *e is not dereferenced while
654                  * the device emulation still writes data into the slot.
655                  * Since the device emulation advances s->cmpProdIdx only after
656                  * updating the slot we want to check it first.
657                  */
658                 barrier();
659                 pvscsi_complete_request(adapter, e);
660                 /*
661                  * This barrier() ensures that compiler doesn't reorder write
662                  * to s->cmpConsIdx before the read of (*e) inside
663                  * pvscsi_complete_request. Otherwise, device emulation may
664                  * overwrite *e before we had a chance to read it.
665                  */
666                 barrier();
667                 s->cmpConsIdx++;
668         }
669 }
670 
671 /*
672  * Translate a Linux SCSI request into a request ring entry.
673  */
674 static int pvscsi_queue_ring(struct pvscsi_adapter *adapter,
675                              struct pvscsi_ctx *ctx, struct scsi_cmnd *cmd)
676 {
677         struct PVSCSIRingsState *s;
678         struct PVSCSIRingReqDesc *e;
679         struct scsi_device *sdev;
680         u32 req_entries;
681 
682         s = adapter->rings_state;
683         sdev = cmd->device;
684         req_entries = s->reqNumEntriesLog2;
685 
686         /*
687          * If this condition holds, we might have room on the request ring, but
688          * we might not have room on the completion ring for the response.
689          * However, we have already ruled out this possibility - we would not
690          * have successfully allocated a context if it were true, since we only
691          * have one context per request entry.  Check for it anyway, since it
692          * would be a serious bug.
693          */
694         if (s->reqProdIdx - s->cmpConsIdx >= 1 << req_entries) {
695                 scmd_printk(KERN_ERR, cmd, "vmw_pvscsi: "
696                             "ring full: reqProdIdx=%d cmpConsIdx=%d\n",
697                             s->reqProdIdx, s->cmpConsIdx);
698                 return -1;
699         }
700 
701         e = adapter->req_ring + (s->reqProdIdx & MASK(req_entries));
702 
703         e->bus    = sdev->channel;
704         e->target = sdev->id;
705         memset(e->lun, 0, sizeof(e->lun));
706         e->lun[1] = sdev->lun;
707 
708         if (cmd->sense_buffer) {
709                 ctx->sensePA = pci_map_single(adapter->dev, cmd->sense_buffer,
710                                               SCSI_SENSE_BUFFERSIZE,
711                                               PCI_DMA_FROMDEVICE);
712                 if (pci_dma_mapping_error(adapter->dev, ctx->sensePA)) {
713                         scmd_printk(KERN_ERR, cmd,
714                                     "vmw_pvscsi: Failed to map sense buffer for DMA.\n");
715                         ctx->sensePA = 0;
716                         return -ENOMEM;
717                 }
718                 e->senseAddr = ctx->sensePA;
719                 e->senseLen = SCSI_SENSE_BUFFERSIZE;
720         } else {
721                 e->senseLen  = 0;
722                 e->senseAddr = 0;
723         }
724         e->cdbLen   = cmd->cmd_len;
725         e->vcpuHint = smp_processor_id();
726         memcpy(e->cdb, cmd->cmnd, e->cdbLen);
727 
728         e->tag = SIMPLE_QUEUE_TAG;
729 
730         if (cmd->sc_data_direction == DMA_FROM_DEVICE)
731                 e->flags = PVSCSI_FLAG_CMD_DIR_TOHOST;
732         else if (cmd->sc_data_direction == DMA_TO_DEVICE)
733                 e->flags = PVSCSI_FLAG_CMD_DIR_TODEVICE;
734         else if (cmd->sc_data_direction == DMA_NONE)
735                 e->flags = PVSCSI_FLAG_CMD_DIR_NONE;
736         else
737                 e->flags = 0;
738 
739         if (pvscsi_map_buffers(adapter, ctx, cmd, e) != 0) {
740                 if (cmd->sense_buffer) {
741                         pci_unmap_single(adapter->dev, ctx->sensePA,
742                                          SCSI_SENSE_BUFFERSIZE,
743                                          PCI_DMA_FROMDEVICE);
744                         ctx->sensePA = 0;
745                 }
746                 return -ENOMEM;
747         }
748 
749         e->context = pvscsi_map_context(adapter, ctx);
750 
751         barrier();
752 
753         s->reqProdIdx++;
754 
755         return 0;
756 }
757 
758 static int pvscsi_queue_lck(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
759 {
760         struct Scsi_Host *host = cmd->device->host;
761         struct pvscsi_adapter *adapter = shost_priv(host);
762         struct pvscsi_ctx *ctx;
763         unsigned long flags;
764 
765         spin_lock_irqsave(&adapter->hw_lock, flags);
766 
767         ctx = pvscsi_acquire_context(adapter, cmd);
768         if (!ctx || pvscsi_queue_ring(adapter, ctx, cmd) != 0) {
769                 if (ctx)
770                         pvscsi_release_context(adapter, ctx);
771                 spin_unlock_irqrestore(&adapter->hw_lock, flags);
772                 return SCSI_MLQUEUE_HOST_BUSY;
773         }
774 
775         cmd->scsi_done = done;
776 
777         dev_dbg(&cmd->device->sdev_gendev,
778                 "queued cmd %p, ctx %p, op=%x\n", cmd, ctx, cmd->cmnd[0]);
779 
780         spin_unlock_irqrestore(&adapter->hw_lock, flags);
781 
782         pvscsi_kick_io(adapter, cmd->cmnd[0]);
783 
784         return 0;
785 }
786 
787 static DEF_SCSI_QCMD(pvscsi_queue)
788 
789 static int pvscsi_abort(struct scsi_cmnd *cmd)
790 {
791         struct pvscsi_adapter *adapter = shost_priv(cmd->device->host);
792         struct pvscsi_ctx *ctx;
793         unsigned long flags;
794         int result = SUCCESS;
795         DECLARE_COMPLETION_ONSTACK(abort_cmp);
796         int done;
797 
798         scmd_printk(KERN_DEBUG, cmd, "task abort on host %u, %p\n",
799                     adapter->host->host_no, cmd);
800 
801         spin_lock_irqsave(&adapter->hw_lock, flags);
802 
803         /*
804          * Poll the completion ring first - we might be trying to abort
805          * a command that is waiting to be dispatched in the completion ring.
806          */
807         pvscsi_process_completion_ring(adapter);
808 
809         /*
810          * If there is no context for the command, it either already succeeded
811          * or else was never properly issued.  Not our problem.
812          */
813         ctx = pvscsi_find_context(adapter, cmd);
814         if (!ctx) {
815                 scmd_printk(KERN_DEBUG, cmd, "Failed to abort cmd %p\n", cmd);
816                 goto out;
817         }
818 
819         /*
820          * Mark that the command has been requested to be aborted and issue
821          * the abort.
822          */
823         ctx->abort_cmp = &abort_cmp;
824 
825         pvscsi_abort_cmd(adapter, ctx);
826         spin_unlock_irqrestore(&adapter->hw_lock, flags);
827         /* Wait for 2 secs for the completion. */
828         done = wait_for_completion_timeout(&abort_cmp, msecs_to_jiffies(2000));
829         spin_lock_irqsave(&adapter->hw_lock, flags);
830 
831         if (!done) {
832                 /*
833                  * Failed to abort the command, unmark the fact that it
834                  * was requested to be aborted.
835                  */
836                 ctx->abort_cmp = NULL;
837                 result = FAILED;
838                 scmd_printk(KERN_DEBUG, cmd,
839                             "Failed to get completion for aborted cmd %p\n",
840                             cmd);
841                 goto out;
842         }
843 
844         /*
845          * Successfully aborted the command.
846          */
847         cmd->result = (DID_ABORT << 16);
848         cmd->scsi_done(cmd);
849 
850 out:
851         spin_unlock_irqrestore(&adapter->hw_lock, flags);
852         return result;
853 }
854 
855 /*
856  * Abort all outstanding requests.  This is only safe to use if the completion
857  * ring will never be walked again or the device has been reset, because it
858  * destroys the 1-1 mapping between context field passed to emulation and our
859  * request structure.
860  */
861 static void pvscsi_reset_all(struct pvscsi_adapter *adapter)
862 {
863         unsigned i;
864 
865         for (i = 0; i < adapter->req_depth; i++) {
866                 struct pvscsi_ctx *ctx = &adapter->cmd_map[i];
867                 struct scsi_cmnd *cmd = ctx->cmd;
868                 if (cmd) {
869                         scmd_printk(KERN_ERR, cmd,
870                                     "Forced reset on cmd %p\n", cmd);
871                         pvscsi_unmap_buffers(adapter, ctx);
872                         pvscsi_release_context(adapter, ctx);
873                         cmd->result = (DID_RESET << 16);
874                         cmd->scsi_done(cmd);
875                 }
876         }
877 }
878 
879 static int pvscsi_host_reset(struct scsi_cmnd *cmd)
880 {
881         struct Scsi_Host *host = cmd->device->host;
882         struct pvscsi_adapter *adapter = shost_priv(host);
883         unsigned long flags;
884         bool use_msg;
885 
886         scmd_printk(KERN_INFO, cmd, "SCSI Host reset\n");
887 
888         spin_lock_irqsave(&adapter->hw_lock, flags);
889 
890         use_msg = adapter->use_msg;
891 
892         if (use_msg) {
893                 adapter->use_msg = 0;
894                 spin_unlock_irqrestore(&adapter->hw_lock, flags);
895 
896                 /*
897                  * Now that we know that the ISR won't add more work on the
898                  * workqueue we can safely flush any outstanding work.
899                  */
900                 flush_workqueue(adapter->workqueue);
901                 spin_lock_irqsave(&adapter->hw_lock, flags);
902         }
903 
904         /*
905          * We're going to tear down the entire ring structure and set it back
906          * up, so stalling new requests until all completions are flushed and
907          * the rings are back in place.
908          */
909 
910         pvscsi_process_request_ring(adapter);
911 
912         ll_adapter_reset(adapter);
913 
914         /*
915          * Now process any completions.  Note we do this AFTER adapter reset,
916          * which is strange, but stops races where completions get posted
917          * between processing the ring and issuing the reset.  The backend will
918          * not touch the ring memory after reset, so the immediately pre-reset
919          * completion ring state is still valid.
920          */
921         pvscsi_process_completion_ring(adapter);
922 
923         pvscsi_reset_all(adapter);
924         adapter->use_msg = use_msg;
925         pvscsi_setup_all_rings(adapter);
926         pvscsi_unmask_intr(adapter);
927 
928         spin_unlock_irqrestore(&adapter->hw_lock, flags);
929 
930         return SUCCESS;
931 }
932 
933 static int pvscsi_bus_reset(struct scsi_cmnd *cmd)
934 {
935         struct Scsi_Host *host = cmd->device->host;
936         struct pvscsi_adapter *adapter = shost_priv(host);
937         unsigned long flags;
938 
939         scmd_printk(KERN_INFO, cmd, "SCSI Bus reset\n");
940 
941         /*
942          * We don't want to queue new requests for this bus after
943          * flushing all pending requests to emulation, since new
944          * requests could then sneak in during this bus reset phase,
945          * so take the lock now.
946          */
947         spin_lock_irqsave(&adapter->hw_lock, flags);
948 
949         pvscsi_process_request_ring(adapter);
950         ll_bus_reset(adapter);
951         pvscsi_process_completion_ring(adapter);
952 
953         spin_unlock_irqrestore(&adapter->hw_lock, flags);
954 
955         return SUCCESS;
956 }
957 
958 static int pvscsi_device_reset(struct scsi_cmnd *cmd)
959 {
960         struct Scsi_Host *host = cmd->device->host;
961         struct pvscsi_adapter *adapter = shost_priv(host);
962         unsigned long flags;
963 
964         scmd_printk(KERN_INFO, cmd, "SCSI device reset on scsi%u:%u\n",
965                     host->host_no, cmd->device->id);
966 
967         /*
968          * We don't want to queue new requests for this device after flushing
969          * all pending requests to emulation, since new requests could then
970          * sneak in during this device reset phase, so take the lock now.
971          */
972         spin_lock_irqsave(&adapter->hw_lock, flags);
973 
974         pvscsi_process_request_ring(adapter);
975         ll_device_reset(adapter, cmd->device->id);
976         pvscsi_process_completion_ring(adapter);
977 
978         spin_unlock_irqrestore(&adapter->hw_lock, flags);
979 
980         return SUCCESS;
981 }
982 
983 static struct scsi_host_template pvscsi_template;
984 
985 static const char *pvscsi_info(struct Scsi_Host *host)
986 {
987         struct pvscsi_adapter *adapter = shost_priv(host);
988         static char buf[256];
989 
990         sprintf(buf, "VMware PVSCSI storage adapter rev %d, req/cmp/msg rings: "
991                 "%u/%u/%u pages, cmd_per_lun=%u", adapter->rev,
992                 adapter->req_pages, adapter->cmp_pages, adapter->msg_pages,
993                 pvscsi_template.cmd_per_lun);
994 
995         return buf;
996 }
997 
998 static struct scsi_host_template pvscsi_template = {
999         .module                         = THIS_MODULE,
1000         .name                           = "VMware PVSCSI Host Adapter",
1001         .proc_name                      = "vmw_pvscsi",
1002         .info                           = pvscsi_info,
1003         .queuecommand                   = pvscsi_queue,
1004         .this_id                        = -1,
1005         .sg_tablesize                   = PVSCSI_MAX_NUM_SG_ENTRIES_PER_SEGMENT,
1006         .dma_boundary                   = UINT_MAX,
1007         .max_sectors                    = 0xffff,
1008         .use_clustering                 = ENABLE_CLUSTERING,
1009         .change_queue_depth             = pvscsi_change_queue_depth,
1010         .eh_abort_handler               = pvscsi_abort,
1011         .eh_device_reset_handler        = pvscsi_device_reset,
1012         .eh_bus_reset_handler           = pvscsi_bus_reset,
1013         .eh_host_reset_handler          = pvscsi_host_reset,
1014 };
1015 
1016 static void pvscsi_process_msg(const struct pvscsi_adapter *adapter,
1017                                const struct PVSCSIRingMsgDesc *e)
1018 {
1019         struct PVSCSIRingsState *s = adapter->rings_state;
1020         struct Scsi_Host *host = adapter->host;
1021         struct scsi_device *sdev;
1022 
1023         printk(KERN_INFO "vmw_pvscsi: msg type: 0x%x - MSG RING: %u/%u (%u) \n",
1024                e->type, s->msgProdIdx, s->msgConsIdx, s->msgNumEntriesLog2);
1025 
1026         BUILD_BUG_ON(PVSCSI_MSG_LAST != 2);
1027 
1028         if (e->type == PVSCSI_MSG_DEV_ADDED) {
1029                 struct PVSCSIMsgDescDevStatusChanged *desc;
1030                 desc = (struct PVSCSIMsgDescDevStatusChanged *)e;
1031 
1032                 printk(KERN_INFO
1033                        "vmw_pvscsi: msg: device added at scsi%u:%u:%u\n",
1034                        desc->bus, desc->target, desc->lun[1]);
1035 
1036                 if (!scsi_host_get(host))
1037                         return;
1038 
1039                 sdev = scsi_device_lookup(host, desc->bus, desc->target,
1040                                           desc->lun[1]);
1041                 if (sdev) {
1042                         printk(KERN_INFO "vmw_pvscsi: device already exists\n");
1043                         scsi_device_put(sdev);
1044                 } else
1045                         scsi_add_device(adapter->host, desc->bus,
1046                                         desc->target, desc->lun[1]);
1047 
1048                 scsi_host_put(host);
1049         } else if (e->type == PVSCSI_MSG_DEV_REMOVED) {
1050                 struct PVSCSIMsgDescDevStatusChanged *desc;
1051                 desc = (struct PVSCSIMsgDescDevStatusChanged *)e;
1052 
1053                 printk(KERN_INFO
1054                        "vmw_pvscsi: msg: device removed at scsi%u:%u:%u\n",
1055                        desc->bus, desc->target, desc->lun[1]);
1056 
1057                 if (!scsi_host_get(host))
1058                         return;
1059 
1060                 sdev = scsi_device_lookup(host, desc->bus, desc->target,
1061                                           desc->lun[1]);
1062                 if (sdev) {
1063                         scsi_remove_device(sdev);
1064                         scsi_device_put(sdev);
1065                 } else
1066                         printk(KERN_INFO
1067                                "vmw_pvscsi: failed to lookup scsi%u:%u:%u\n",
1068                                desc->bus, desc->target, desc->lun[1]);
1069 
1070                 scsi_host_put(host);
1071         }
1072 }
1073 
1074 static int pvscsi_msg_pending(const struct pvscsi_adapter *adapter)
1075 {
1076         struct PVSCSIRingsState *s = adapter->rings_state;
1077 
1078         return s->msgProdIdx != s->msgConsIdx;
1079 }
1080 
1081 static void pvscsi_process_msg_ring(const struct pvscsi_adapter *adapter)
1082 {
1083         struct PVSCSIRingsState *s = adapter->rings_state;
1084         struct PVSCSIRingMsgDesc *ring = adapter->msg_ring;
1085         u32 msg_entries = s->msgNumEntriesLog2;
1086 
1087         while (pvscsi_msg_pending(adapter)) {
1088                 struct PVSCSIRingMsgDesc *e = ring + (s->msgConsIdx &
1089                                                       MASK(msg_entries));
1090 
1091                 barrier();
1092                 pvscsi_process_msg(adapter, e);
1093                 barrier();
1094                 s->msgConsIdx++;
1095         }
1096 }
1097 
1098 static void pvscsi_msg_workqueue_handler(struct work_struct *data)
1099 {
1100         struct pvscsi_adapter *adapter;
1101 
1102         adapter = container_of(data, struct pvscsi_adapter, work);
1103 
1104         pvscsi_process_msg_ring(adapter);
1105 }
1106 
1107 static int pvscsi_setup_msg_workqueue(struct pvscsi_adapter *adapter)
1108 {
1109         char name[32];
1110 
1111         if (!pvscsi_use_msg)
1112                 return 0;
1113 
1114         pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_COMMAND,
1115                          PVSCSI_CMD_SETUP_MSG_RING);
1116 
1117         if (pvscsi_reg_read(adapter, PVSCSI_REG_OFFSET_COMMAND_STATUS) == -1)
1118                 return 0;
1119 
1120         snprintf(name, sizeof(name),
1121                  "vmw_pvscsi_wq_%u", adapter->host->host_no);
1122 
1123         adapter->workqueue = create_singlethread_workqueue(name);
1124         if (!adapter->workqueue) {
1125                 printk(KERN_ERR "vmw_pvscsi: failed to create work queue\n");
1126                 return 0;
1127         }
1128         INIT_WORK(&adapter->work, pvscsi_msg_workqueue_handler);
1129 
1130         return 1;
1131 }
1132 
1133 static bool pvscsi_setup_req_threshold(struct pvscsi_adapter *adapter,
1134                                       bool enable)
1135 {
1136         u32 val;
1137 
1138         if (!pvscsi_use_req_threshold)
1139                 return false;
1140 
1141         pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_COMMAND,
1142                          PVSCSI_CMD_SETUP_REQCALLTHRESHOLD);
1143         val = pvscsi_reg_read(adapter, PVSCSI_REG_OFFSET_COMMAND_STATUS);
1144         if (val == -1) {
1145                 printk(KERN_INFO "vmw_pvscsi: device does not support req_threshold\n");
1146                 return false;
1147         } else {
1148                 struct PVSCSICmdDescSetupReqCall cmd_msg = { 0 };
1149                 cmd_msg.enable = enable;
1150                 printk(KERN_INFO
1151                        "vmw_pvscsi: %sabling reqCallThreshold\n",
1152                         enable ? "en" : "dis");
1153                 pvscsi_write_cmd_desc(adapter,
1154                                       PVSCSI_CMD_SETUP_REQCALLTHRESHOLD,
1155                                       &cmd_msg, sizeof(cmd_msg));
1156                 return pvscsi_reg_read(adapter,
1157                                        PVSCSI_REG_OFFSET_COMMAND_STATUS) != 0;
1158         }
1159 }
1160 
1161 static irqreturn_t pvscsi_isr(int irq, void *devp)
1162 {
1163         struct pvscsi_adapter *adapter = devp;
1164         int handled;
1165 
1166         if (adapter->use_msi || adapter->use_msix)
1167                 handled = true;
1168         else {
1169                 u32 val = pvscsi_read_intr_status(adapter);
1170                 handled = (val & PVSCSI_INTR_ALL_SUPPORTED) != 0;
1171                 if (handled)
1172                         pvscsi_write_intr_status(devp, val);
1173         }
1174 
1175         if (handled) {
1176                 unsigned long flags;
1177 
1178                 spin_lock_irqsave(&adapter->hw_lock, flags);
1179 
1180                 pvscsi_process_completion_ring(adapter);
1181                 if (adapter->use_msg && pvscsi_msg_pending(adapter))
1182                         queue_work(adapter->workqueue, &adapter->work);
1183 
1184                 spin_unlock_irqrestore(&adapter->hw_lock, flags);
1185         }
1186 
1187         return IRQ_RETVAL(handled);
1188 }
1189 
1190 static void pvscsi_free_sgls(const struct pvscsi_adapter *adapter)
1191 {
1192         struct pvscsi_ctx *ctx = adapter->cmd_map;
1193         unsigned i;
1194 
1195         for (i = 0; i < adapter->req_depth; ++i, ++ctx)
1196                 free_pages((unsigned long)ctx->sgl, get_order(SGL_SIZE));
1197 }
1198 
1199 static int pvscsi_setup_msix(const struct pvscsi_adapter *adapter,
1200                              unsigned int *irq)
1201 {
1202         struct msix_entry entry = { 0, PVSCSI_VECTOR_COMPLETION };
1203         int ret;
1204 
1205         ret = pci_enable_msix_exact(adapter->dev, &entry, 1);
1206         if (ret)
1207                 return ret;
1208 
1209         *irq = entry.vector;
1210 
1211         return 0;
1212 }
1213 
1214 static void pvscsi_shutdown_intr(struct pvscsi_adapter *adapter)
1215 {
1216         if (adapter->irq) {
1217                 free_irq(adapter->irq, adapter);
1218                 adapter->irq = 0;
1219         }
1220         if (adapter->use_msi) {
1221                 pci_disable_msi(adapter->dev);
1222                 adapter->use_msi = 0;
1223         } else if (adapter->use_msix) {
1224                 pci_disable_msix(adapter->dev);
1225                 adapter->use_msix = 0;
1226         }
1227 }
1228 
1229 static void pvscsi_release_resources(struct pvscsi_adapter *adapter)
1230 {
1231         pvscsi_shutdown_intr(adapter);
1232 
1233         if (adapter->workqueue)
1234                 destroy_workqueue(adapter->workqueue);
1235 
1236         if (adapter->mmioBase)
1237                 pci_iounmap(adapter->dev, adapter->mmioBase);
1238 
1239         pci_release_regions(adapter->dev);
1240 
1241         if (adapter->cmd_map) {
1242                 pvscsi_free_sgls(adapter);
1243                 kfree(adapter->cmd_map);
1244         }
1245 
1246         if (adapter->rings_state)
1247                 pci_free_consistent(adapter->dev, PAGE_SIZE,
1248                                     adapter->rings_state, adapter->ringStatePA);
1249 
1250         if (adapter->req_ring)
1251                 pci_free_consistent(adapter->dev,
1252                                     adapter->req_pages * PAGE_SIZE,
1253                                     adapter->req_ring, adapter->reqRingPA);
1254 
1255         if (adapter->cmp_ring)
1256                 pci_free_consistent(adapter->dev,
1257                                     adapter->cmp_pages * PAGE_SIZE,
1258                                     adapter->cmp_ring, adapter->cmpRingPA);
1259 
1260         if (adapter->msg_ring)
1261                 pci_free_consistent(adapter->dev,
1262                                     adapter->msg_pages * PAGE_SIZE,
1263                                     adapter->msg_ring, adapter->msgRingPA);
1264 }
1265 
1266 /*
1267  * Allocate scatter gather lists.
1268  *
1269  * These are statically allocated.  Trying to be clever was not worth it.
1270  *
1271  * Dynamic allocation can fail, and we can't go deep into the memory
1272  * allocator, since we're a SCSI driver, and trying too hard to allocate
1273  * memory might generate disk I/O.  We also don't want to fail disk I/O
1274  * in that case because we can't get an allocation - the I/O could be
1275  * trying to swap out data to free memory.  Since that is pathological,
1276  * just use a statically allocated scatter list.
1277  *
1278  */
1279 static int pvscsi_allocate_sg(struct pvscsi_adapter *adapter)
1280 {
1281         struct pvscsi_ctx *ctx;
1282         int i;
1283 
1284         ctx = adapter->cmd_map;
1285         BUILD_BUG_ON(sizeof(struct pvscsi_sg_list) > SGL_SIZE);
1286 
1287         for (i = 0; i < adapter->req_depth; ++i, ++ctx) {
1288                 ctx->sgl = (void *)__get_free_pages(GFP_KERNEL,
1289                                                     get_order(SGL_SIZE));
1290                 ctx->sglPA = 0;
1291                 BUG_ON(!IS_ALIGNED(((unsigned long)ctx->sgl), PAGE_SIZE));
1292                 if (!ctx->sgl) {
1293                         for (; i >= 0; --i, --ctx) {
1294                                 free_pages((unsigned long)ctx->sgl,
1295                                            get_order(SGL_SIZE));
1296                                 ctx->sgl = NULL;
1297                         }
1298                         return -ENOMEM;
1299                 }
1300         }
1301 
1302         return 0;
1303 }
1304 
1305 /*
1306  * Query the device, fetch the config info and return the
1307  * maximum number of targets on the adapter. In case of
1308  * failure due to any reason return default i.e. 16.
1309  */
1310 static u32 pvscsi_get_max_targets(struct pvscsi_adapter *adapter)
1311 {
1312         struct PVSCSICmdDescConfigCmd cmd;
1313         struct PVSCSIConfigPageHeader *header;
1314         struct device *dev;
1315         dma_addr_t configPagePA;
1316         void *config_page;
1317         u32 numPhys = 16;
1318 
1319         dev = pvscsi_dev(adapter);
1320         config_page = pci_alloc_consistent(adapter->dev, PAGE_SIZE,
1321                                            &configPagePA);
1322         if (!config_page) {
1323                 dev_warn(dev, "vmw_pvscsi: failed to allocate memory for config page\n");
1324                 goto exit;
1325         }
1326         BUG_ON(configPagePA & ~PAGE_MASK);
1327 
1328         /* Fetch config info from the device. */
1329         cmd.configPageAddress = ((u64)PVSCSI_CONFIG_CONTROLLER_ADDRESS) << 32;
1330         cmd.configPageNum = PVSCSI_CONFIG_PAGE_CONTROLLER;
1331         cmd.cmpAddr = configPagePA;
1332         cmd._pad = 0;
1333 
1334         /*
1335          * Mark the completion page header with error values. If the device
1336          * completes the command successfully, it sets the status values to
1337          * indicate success.
1338          */
1339         header = config_page;
1340         memset(header, 0, sizeof *header);
1341         header->hostStatus = BTSTAT_INVPARAM;
1342         header->scsiStatus = SDSTAT_CHECK;
1343 
1344         pvscsi_write_cmd_desc(adapter, PVSCSI_CMD_CONFIG, &cmd, sizeof cmd);
1345 
1346         if (header->hostStatus == BTSTAT_SUCCESS &&
1347             header->scsiStatus == SDSTAT_GOOD) {
1348                 struct PVSCSIConfigPageController *config;
1349 
1350                 config = config_page;
1351                 numPhys = config->numPhys;
1352         } else
1353                 dev_warn(dev, "vmw_pvscsi: PVSCSI_CMD_CONFIG failed. hostStatus = 0x%x, scsiStatus = 0x%x\n",
1354                          header->hostStatus, header->scsiStatus);
1355         pci_free_consistent(adapter->dev, PAGE_SIZE, config_page, configPagePA);
1356 exit:
1357         return numPhys;
1358 }
1359 
1360 static int pvscsi_probe(struct pci_dev *pdev, const struct pci_device_id *id)
1361 {
1362         struct pvscsi_adapter *adapter;
1363         struct pvscsi_adapter adapter_temp;
1364         struct Scsi_Host *host = NULL;
1365         unsigned int i;
1366         unsigned long flags = 0;
1367         int error;
1368         u32 max_id;
1369 
1370         error = -ENODEV;
1371 
1372         if (pci_enable_device(pdev))
1373                 return error;
1374 
1375         if (pci_set_dma_mask(pdev, DMA_BIT_MASK(64)) == 0 &&
1376             pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64)) == 0) {
1377                 printk(KERN_INFO "vmw_pvscsi: using 64bit dma\n");
1378         } else if (pci_set_dma_mask(pdev, DMA_BIT_MASK(32)) == 0 &&
1379                    pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32)) == 0) {
1380                 printk(KERN_INFO "vmw_pvscsi: using 32bit dma\n");
1381         } else {
1382                 printk(KERN_ERR "vmw_pvscsi: failed to set DMA mask\n");
1383                 goto out_disable_device;
1384         }
1385 
1386         /*
1387          * Let's use a temp pvscsi_adapter struct until we find the number of
1388          * targets on the adapter, after that we will switch to the real
1389          * allocated struct.
1390          */
1391         adapter = &adapter_temp;
1392         memset(adapter, 0, sizeof(*adapter));
1393         adapter->dev  = pdev;
1394         adapter->rev = pdev->revision;
1395 
1396         if (pci_request_regions(pdev, "vmw_pvscsi")) {
1397                 printk(KERN_ERR "vmw_pvscsi: pci memory selection failed\n");
1398                 goto out_disable_device;
1399         }
1400 
1401         for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
1402                 if ((pci_resource_flags(pdev, i) & PCI_BASE_ADDRESS_SPACE_IO))
1403                         continue;
1404 
1405                 if (pci_resource_len(pdev, i) < PVSCSI_MEM_SPACE_SIZE)
1406                         continue;
1407 
1408                 break;
1409         }
1410 
1411         if (i == DEVICE_COUNT_RESOURCE) {
1412                 printk(KERN_ERR
1413                        "vmw_pvscsi: adapter has no suitable MMIO region\n");
1414                 goto out_release_resources_and_disable;
1415         }
1416 
1417         adapter->mmioBase = pci_iomap(pdev, i, PVSCSI_MEM_SPACE_SIZE);
1418 
1419         if (!adapter->mmioBase) {
1420                 printk(KERN_ERR
1421                        "vmw_pvscsi: can't iomap for BAR %d memsize %lu\n",
1422                        i, PVSCSI_MEM_SPACE_SIZE);
1423                 goto out_release_resources_and_disable;
1424         }
1425 
1426         pci_set_master(pdev);
1427 
1428         /*
1429          * Ask the device for max number of targets before deciding the
1430          * default pvscsi_ring_pages value.
1431          */
1432         max_id = pvscsi_get_max_targets(adapter);
1433         printk(KERN_INFO "vmw_pvscsi: max_id: %u\n", max_id);
1434 
1435         if (pvscsi_ring_pages == 0)
1436                 /*
1437                  * Set the right default value. Up to 16 it is 8, above it is
1438                  * max.
1439                  */
1440                 pvscsi_ring_pages = (max_id > 16) ?
1441                         PVSCSI_SETUP_RINGS_MAX_NUM_PAGES :
1442                         PVSCSI_DEFAULT_NUM_PAGES_PER_RING;
1443         printk(KERN_INFO
1444                "vmw_pvscsi: setting ring_pages to %d\n",
1445                pvscsi_ring_pages);
1446 
1447         pvscsi_template.can_queue =
1448                 min(PVSCSI_MAX_NUM_PAGES_REQ_RING, pvscsi_ring_pages) *
1449                 PVSCSI_MAX_NUM_REQ_ENTRIES_PER_PAGE;
1450         pvscsi_template.cmd_per_lun =
1451                 min(pvscsi_template.can_queue, pvscsi_cmd_per_lun);
1452         host = scsi_host_alloc(&pvscsi_template, sizeof(struct pvscsi_adapter));
1453         if (!host) {
1454                 printk(KERN_ERR "vmw_pvscsi: failed to allocate host\n");
1455                 goto out_release_resources_and_disable;
1456         }
1457 
1458         /*
1459          * Let's use the real pvscsi_adapter struct here onwards.
1460          */
1461         adapter = shost_priv(host);
1462         memset(adapter, 0, sizeof(*adapter));
1463         adapter->dev  = pdev;
1464         adapter->host = host;
1465         /*
1466          * Copy back what we already have to the allocated adapter struct.
1467          */
1468         adapter->rev = adapter_temp.rev;
1469         adapter->mmioBase = adapter_temp.mmioBase;
1470 
1471         spin_lock_init(&adapter->hw_lock);
1472         host->max_channel = 0;
1473         host->max_lun     = 1;
1474         host->max_cmd_len = 16;
1475         host->max_id      = max_id;
1476 
1477         pci_set_drvdata(pdev, host);
1478 
1479         ll_adapter_reset(adapter);
1480 
1481         adapter->use_msg = pvscsi_setup_msg_workqueue(adapter);
1482 
1483         error = pvscsi_allocate_rings(adapter);
1484         if (error) {
1485                 printk(KERN_ERR "vmw_pvscsi: unable to allocate ring memory\n");
1486                 goto out_release_resources;
1487         }
1488 
1489         /*
1490          * From this point on we should reset the adapter if anything goes
1491          * wrong.
1492          */
1493         pvscsi_setup_all_rings(adapter);
1494 
1495         adapter->cmd_map = kcalloc(adapter->req_depth,
1496                                    sizeof(struct pvscsi_ctx), GFP_KERNEL);
1497         if (!adapter->cmd_map) {
1498                 printk(KERN_ERR "vmw_pvscsi: failed to allocate memory.\n");
1499                 error = -ENOMEM;
1500                 goto out_reset_adapter;
1501         }
1502 
1503         INIT_LIST_HEAD(&adapter->cmd_pool);
1504         for (i = 0; i < adapter->req_depth; i++) {
1505                 struct pvscsi_ctx *ctx = adapter->cmd_map + i;
1506                 list_add(&ctx->list, &adapter->cmd_pool);
1507         }
1508 
1509         error = pvscsi_allocate_sg(adapter);
1510         if (error) {
1511                 printk(KERN_ERR "vmw_pvscsi: unable to allocate s/g table\n");
1512                 goto out_reset_adapter;
1513         }
1514 
1515         if (!pvscsi_disable_msix &&
1516             pvscsi_setup_msix(adapter, &adapter->irq) == 0) {
1517                 printk(KERN_INFO "vmw_pvscsi: using MSI-X\n");
1518                 adapter->use_msix = 1;
1519         } else if (!pvscsi_disable_msi && pci_enable_msi(pdev) == 0) {
1520                 printk(KERN_INFO "vmw_pvscsi: using MSI\n");
1521                 adapter->use_msi = 1;
1522                 adapter->irq = pdev->irq;
1523         } else {
1524                 printk(KERN_INFO "vmw_pvscsi: using INTx\n");
1525                 adapter->irq = pdev->irq;
1526                 flags = IRQF_SHARED;
1527         }
1528 
1529         adapter->use_req_threshold = pvscsi_setup_req_threshold(adapter, true);
1530         printk(KERN_DEBUG "vmw_pvscsi: driver-based request coalescing %sabled\n",
1531                adapter->use_req_threshold ? "en" : "dis");
1532 
1533         error = request_irq(adapter->irq, pvscsi_isr, flags,
1534                             "vmw_pvscsi", adapter);
1535         if (error) {
1536                 printk(KERN_ERR
1537                        "vmw_pvscsi: unable to request IRQ: %d\n", error);
1538                 adapter->irq = 0;
1539                 goto out_reset_adapter;
1540         }
1541 
1542         error = scsi_add_host(host, &pdev->dev);
1543         if (error) {
1544                 printk(KERN_ERR
1545                        "vmw_pvscsi: scsi_add_host failed: %d\n", error);
1546                 goto out_reset_adapter;
1547         }
1548 
1549         dev_info(&pdev->dev, "VMware PVSCSI rev %d host #%u\n",
1550                  adapter->rev, host->host_no);
1551 
1552         pvscsi_unmask_intr(adapter);
1553 
1554         scsi_scan_host(host);
1555 
1556         return 0;
1557 
1558 out_reset_adapter:
1559         ll_adapter_reset(adapter);
1560 out_release_resources:
1561         pvscsi_release_resources(adapter);
1562         scsi_host_put(host);
1563 out_disable_device:
1564         pci_disable_device(pdev);
1565 
1566         return error;
1567 
1568 out_release_resources_and_disable:
1569         pvscsi_release_resources(adapter);
1570         goto out_disable_device;
1571 }
1572 
1573 static void __pvscsi_shutdown(struct pvscsi_adapter *adapter)
1574 {
1575         pvscsi_mask_intr(adapter);
1576 
1577         if (adapter->workqueue)
1578                 flush_workqueue(adapter->workqueue);
1579 
1580         pvscsi_shutdown_intr(adapter);
1581 
1582         pvscsi_process_request_ring(adapter);
1583         pvscsi_process_completion_ring(adapter);
1584         ll_adapter_reset(adapter);
1585 }
1586 
1587 static void pvscsi_shutdown(struct pci_dev *dev)
1588 {
1589         struct Scsi_Host *host = pci_get_drvdata(dev);
1590         struct pvscsi_adapter *adapter = shost_priv(host);
1591 
1592         __pvscsi_shutdown(adapter);
1593 }
1594 
1595 static void pvscsi_remove(struct pci_dev *pdev)
1596 {
1597         struct Scsi_Host *host = pci_get_drvdata(pdev);
1598         struct pvscsi_adapter *adapter = shost_priv(host);
1599 
1600         scsi_remove_host(host);
1601 
1602         __pvscsi_shutdown(adapter);
1603         pvscsi_release_resources(adapter);
1604 
1605         scsi_host_put(host);
1606 
1607         pci_disable_device(pdev);
1608 }
1609 
1610 static struct pci_driver pvscsi_pci_driver = {
1611         .name           = "vmw_pvscsi",
1612         .id_table       = pvscsi_pci_tbl,
1613         .probe          = pvscsi_probe,
1614         .remove         = pvscsi_remove,
1615         .shutdown       = pvscsi_shutdown,
1616 };
1617 
1618 static int __init pvscsi_init(void)
1619 {
1620         pr_info("%s - version %s\n",
1621                 PVSCSI_LINUX_DRIVER_DESC, PVSCSI_DRIVER_VERSION_STRING);
1622         return pci_register_driver(&pvscsi_pci_driver);
1623 }
1624 
1625 static void __exit pvscsi_exit(void)
1626 {
1627         pci_unregister_driver(&pvscsi_pci_driver);
1628 }
1629 
1630 module_init(pvscsi_init);
1631 module_exit(pvscsi_exit);
1632 

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