xref: /linux/drivers/scsi/vmw_pvscsi.c (revision 1a2ac6d7ecdcde74a4e16f31de64124160fc7237)
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  */
21 
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/interrupt.h>
25 #include <linux/slab.h>
26 #include <linux/workqueue.h>
27 #include <linux/pci.h>
28 
29 #include <scsi/scsi.h>
30 #include <scsi/scsi_host.h>
31 #include <scsi/scsi_cmnd.h>
32 #include <scsi/scsi_device.h>
33 #include <scsi/scsi_tcq.h>
34 
35 #include "vmw_pvscsi.h"
36 
37 #define PVSCSI_LINUX_DRIVER_DESC "VMware PVSCSI driver"
38 
39 MODULE_DESCRIPTION(PVSCSI_LINUX_DRIVER_DESC);
40 MODULE_AUTHOR("VMware, Inc.");
41 MODULE_LICENSE("GPL");
42 MODULE_VERSION(PVSCSI_DRIVER_VERSION_STRING);
43 
44 #define PVSCSI_DEFAULT_NUM_PAGES_PER_RING	8
45 #define PVSCSI_DEFAULT_NUM_PAGES_MSG_RING	1
46 #define PVSCSI_DEFAULT_QUEUE_DEPTH		254
47 #define SGL_SIZE				PAGE_SIZE
48 
49 struct pvscsi_sg_list {
50 	struct PVSCSISGElement sge[PVSCSI_MAX_NUM_SG_ENTRIES_PER_SEGMENT];
51 };
52 
53 struct pvscsi_ctx {
54 	/*
55 	 * The index of the context in cmd_map serves as the context ID for a
56 	 * 1-to-1 mapping completions back to requests.
57 	 */
58 	struct scsi_cmnd	*cmd;
59 	struct pvscsi_sg_list	*sgl;
60 	struct list_head	list;
61 	dma_addr_t		dataPA;
62 	dma_addr_t		sensePA;
63 	dma_addr_t		sglPA;
64 	struct completion	*abort_cmp;
65 };
66 
67 struct pvscsi_adapter {
68 	char				*mmioBase;
69 	u8				rev;
70 	bool				use_msg;
71 	bool				use_req_threshold;
72 
73 	spinlock_t			hw_lock;
74 
75 	struct workqueue_struct		*workqueue;
76 	struct work_struct		work;
77 
78 	struct PVSCSIRingReqDesc	*req_ring;
79 	unsigned			req_pages;
80 	unsigned			req_depth;
81 	dma_addr_t			reqRingPA;
82 
83 	struct PVSCSIRingCmpDesc	*cmp_ring;
84 	unsigned			cmp_pages;
85 	dma_addr_t			cmpRingPA;
86 
87 	struct PVSCSIRingMsgDesc	*msg_ring;
88 	unsigned			msg_pages;
89 	dma_addr_t			msgRingPA;
90 
91 	struct PVSCSIRingsState		*rings_state;
92 	dma_addr_t			ringStatePA;
93 
94 	struct pci_dev			*dev;
95 	struct Scsi_Host		*host;
96 
97 	struct list_head		cmd_pool;
98 	struct pvscsi_ctx		*cmd_map;
99 };
100 
101 
102 /* Command line parameters */
103 static int pvscsi_ring_pages;
104 static int pvscsi_msg_ring_pages = PVSCSI_DEFAULT_NUM_PAGES_MSG_RING;
105 static int pvscsi_cmd_per_lun    = PVSCSI_DEFAULT_QUEUE_DEPTH;
106 static bool pvscsi_disable_msi;
107 static bool pvscsi_disable_msix;
108 static bool pvscsi_use_msg       = true;
109 static bool pvscsi_use_req_threshold = true;
110 
111 #define PVSCSI_RW (S_IRUSR | S_IWUSR)
112 
113 module_param_named(ring_pages, pvscsi_ring_pages, int, PVSCSI_RW);
114 MODULE_PARM_DESC(ring_pages, "Number of pages per req/cmp ring - (default="
115 		 __stringify(PVSCSI_DEFAULT_NUM_PAGES_PER_RING)
116 		 "[up to 16 targets],"
117 		 __stringify(PVSCSI_SETUP_RINGS_MAX_NUM_PAGES)
118 		 "[for 16+ targets])");
119 
120 module_param_named(msg_ring_pages, pvscsi_msg_ring_pages, int, PVSCSI_RW);
121 MODULE_PARM_DESC(msg_ring_pages, "Number of pages for the msg ring - (default="
122 		 __stringify(PVSCSI_DEFAULT_NUM_PAGES_MSG_RING) ")");
123 
124 module_param_named(cmd_per_lun, pvscsi_cmd_per_lun, int, PVSCSI_RW);
125 MODULE_PARM_DESC(cmd_per_lun, "Maximum commands per lun - (default="
126 		 __stringify(PVSCSI_DEFAULT_QUEUE_DEPTH) ")");
127 
128 module_param_named(disable_msi, pvscsi_disable_msi, bool, PVSCSI_RW);
129 MODULE_PARM_DESC(disable_msi, "Disable MSI use in driver - (default=0)");
130 
131 module_param_named(disable_msix, pvscsi_disable_msix, bool, PVSCSI_RW);
132 MODULE_PARM_DESC(disable_msix, "Disable MSI-X use in driver - (default=0)");
133 
134 module_param_named(use_msg, pvscsi_use_msg, bool, PVSCSI_RW);
135 MODULE_PARM_DESC(use_msg, "Use msg ring when available - (default=1)");
136 
137 module_param_named(use_req_threshold, pvscsi_use_req_threshold,
138 		   bool, PVSCSI_RW);
139 MODULE_PARM_DESC(use_req_threshold, "Use driver-based request coalescing if configured - (default=1)");
140 
141 static const struct pci_device_id pvscsi_pci_tbl[] = {
142 	{ PCI_VDEVICE(VMWARE, PCI_DEVICE_ID_VMWARE_PVSCSI) },
143 	{ 0 }
144 };
145 
146 MODULE_DEVICE_TABLE(pci, pvscsi_pci_tbl);
147 
148 static struct device *
149 pvscsi_dev(const struct pvscsi_adapter *adapter)
150 {
151 	return &(adapter->dev->dev);
152 }
153 
154 static struct pvscsi_ctx *
155 pvscsi_find_context(const struct pvscsi_adapter *adapter, struct scsi_cmnd *cmd)
156 {
157 	struct pvscsi_ctx *ctx, *end;
158 
159 	end = &adapter->cmd_map[adapter->req_depth];
160 	for (ctx = adapter->cmd_map; ctx < end; ctx++)
161 		if (ctx->cmd == cmd)
162 			return ctx;
163 
164 	return NULL;
165 }
166 
167 static struct pvscsi_ctx *
168 pvscsi_acquire_context(struct pvscsi_adapter *adapter, struct scsi_cmnd *cmd)
169 {
170 	struct pvscsi_ctx *ctx;
171 
172 	if (list_empty(&adapter->cmd_pool))
173 		return NULL;
174 
175 	ctx = list_first_entry(&adapter->cmd_pool, struct pvscsi_ctx, list);
176 	ctx->cmd = cmd;
177 	list_del(&ctx->list);
178 
179 	return ctx;
180 }
181 
182 static void pvscsi_release_context(struct pvscsi_adapter *adapter,
183 				   struct pvscsi_ctx *ctx)
184 {
185 	ctx->cmd = NULL;
186 	ctx->abort_cmp = NULL;
187 	list_add(&ctx->list, &adapter->cmd_pool);
188 }
189 
190 /*
191  * Map a pvscsi_ctx struct to a context ID field value; we map to a simple
192  * non-zero integer. ctx always points to an entry in cmd_map array, hence
193  * the return value is always >=1.
194  */
195 static u64 pvscsi_map_context(const struct pvscsi_adapter *adapter,
196 			      const struct pvscsi_ctx *ctx)
197 {
198 	return ctx - adapter->cmd_map + 1;
199 }
200 
201 static struct pvscsi_ctx *
202 pvscsi_get_context(const struct pvscsi_adapter *adapter, u64 context)
203 {
204 	return &adapter->cmd_map[context - 1];
205 }
206 
207 static void pvscsi_reg_write(const struct pvscsi_adapter *adapter,
208 			     u32 offset, u32 val)
209 {
210 	writel(val, adapter->mmioBase + offset);
211 }
212 
213 static u32 pvscsi_reg_read(const struct pvscsi_adapter *adapter, u32 offset)
214 {
215 	return readl(adapter->mmioBase + offset);
216 }
217 
218 static u32 pvscsi_read_intr_status(const struct pvscsi_adapter *adapter)
219 {
220 	return pvscsi_reg_read(adapter, PVSCSI_REG_OFFSET_INTR_STATUS);
221 }
222 
223 static void pvscsi_write_intr_status(const struct pvscsi_adapter *adapter,
224 				     u32 val)
225 {
226 	pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_INTR_STATUS, val);
227 }
228 
229 static void pvscsi_unmask_intr(const struct pvscsi_adapter *adapter)
230 {
231 	u32 intr_bits;
232 
233 	intr_bits = PVSCSI_INTR_CMPL_MASK;
234 	if (adapter->use_msg)
235 		intr_bits |= PVSCSI_INTR_MSG_MASK;
236 
237 	pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_INTR_MASK, intr_bits);
238 }
239 
240 static void pvscsi_mask_intr(const struct pvscsi_adapter *adapter)
241 {
242 	pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_INTR_MASK, 0);
243 }
244 
245 static void pvscsi_write_cmd_desc(const struct pvscsi_adapter *adapter,
246 				  u32 cmd, const void *desc, size_t len)
247 {
248 	const u32 *ptr = desc;
249 	size_t i;
250 
251 	len /= sizeof(*ptr);
252 	pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_COMMAND, cmd);
253 	for (i = 0; i < len; i++)
254 		pvscsi_reg_write(adapter,
255 				 PVSCSI_REG_OFFSET_COMMAND_DATA, ptr[i]);
256 }
257 
258 static void pvscsi_abort_cmd(const struct pvscsi_adapter *adapter,
259 			     const struct pvscsi_ctx *ctx)
260 {
261 	struct PVSCSICmdDescAbortCmd cmd = { 0 };
262 
263 	cmd.target = ctx->cmd->device->id;
264 	cmd.context = pvscsi_map_context(adapter, ctx);
265 
266 	pvscsi_write_cmd_desc(adapter, PVSCSI_CMD_ABORT_CMD, &cmd, sizeof(cmd));
267 }
268 
269 static void pvscsi_kick_rw_io(const struct pvscsi_adapter *adapter)
270 {
271 	pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_KICK_RW_IO, 0);
272 }
273 
274 static void pvscsi_process_request_ring(const struct pvscsi_adapter *adapter)
275 {
276 	pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_KICK_NON_RW_IO, 0);
277 }
278 
279 static int scsi_is_rw(unsigned char op)
280 {
281 	return op == READ_6  || op == WRITE_6 ||
282 	       op == READ_10 || op == WRITE_10 ||
283 	       op == READ_12 || op == WRITE_12 ||
284 	       op == READ_16 || op == WRITE_16;
285 }
286 
287 static void pvscsi_kick_io(const struct pvscsi_adapter *adapter,
288 			   unsigned char op)
289 {
290 	if (scsi_is_rw(op)) {
291 		struct PVSCSIRingsState *s = adapter->rings_state;
292 
293 		if (!adapter->use_req_threshold ||
294 		    s->reqProdIdx - s->reqConsIdx >= s->reqCallThreshold)
295 			pvscsi_kick_rw_io(adapter);
296 	} else {
297 		pvscsi_process_request_ring(adapter);
298 	}
299 }
300 
301 static void ll_adapter_reset(const struct pvscsi_adapter *adapter)
302 {
303 	dev_dbg(pvscsi_dev(adapter), "Adapter Reset on %p\n", adapter);
304 
305 	pvscsi_write_cmd_desc(adapter, PVSCSI_CMD_ADAPTER_RESET, NULL, 0);
306 }
307 
308 static void ll_bus_reset(const struct pvscsi_adapter *adapter)
309 {
310 	dev_dbg(pvscsi_dev(adapter), "Resetting bus on %p\n", adapter);
311 
312 	pvscsi_write_cmd_desc(adapter, PVSCSI_CMD_RESET_BUS, NULL, 0);
313 }
314 
315 static void ll_device_reset(const struct pvscsi_adapter *adapter, u32 target)
316 {
317 	struct PVSCSICmdDescResetDevice cmd = { 0 };
318 
319 	dev_dbg(pvscsi_dev(adapter), "Resetting device: target=%u\n", target);
320 
321 	cmd.target = target;
322 
323 	pvscsi_write_cmd_desc(adapter, PVSCSI_CMD_RESET_DEVICE,
324 			      &cmd, sizeof(cmd));
325 }
326 
327 static void pvscsi_create_sg(struct pvscsi_ctx *ctx,
328 			     struct scatterlist *sg, unsigned count)
329 {
330 	unsigned i;
331 	struct PVSCSISGElement *sge;
332 
333 	BUG_ON(count > PVSCSI_MAX_NUM_SG_ENTRIES_PER_SEGMENT);
334 
335 	sge = &ctx->sgl->sge[0];
336 	for (i = 0; i < count; i++, sg = sg_next(sg)) {
337 		sge[i].addr   = sg_dma_address(sg);
338 		sge[i].length = sg_dma_len(sg);
339 		sge[i].flags  = 0;
340 	}
341 }
342 
343 /*
344  * Map all data buffers for a command into PCI space and
345  * setup the scatter/gather list if needed.
346  */
347 static int pvscsi_map_buffers(struct pvscsi_adapter *adapter,
348 			      struct pvscsi_ctx *ctx, struct scsi_cmnd *cmd,
349 			      struct PVSCSIRingReqDesc *e)
350 {
351 	unsigned count;
352 	unsigned bufflen = scsi_bufflen(cmd);
353 	struct scatterlist *sg;
354 
355 	e->dataLen = bufflen;
356 	e->dataAddr = 0;
357 	if (bufflen == 0)
358 		return 0;
359 
360 	sg = scsi_sglist(cmd);
361 	count = scsi_sg_count(cmd);
362 	if (count != 0) {
363 		int segs = scsi_dma_map(cmd);
364 
365 		if (segs == -ENOMEM) {
366 			scmd_printk(KERN_DEBUG, cmd,
367 				    "vmw_pvscsi: Failed to map cmd sglist for DMA.\n");
368 			return -ENOMEM;
369 		} else if (segs > 1) {
370 			pvscsi_create_sg(ctx, sg, segs);
371 
372 			e->flags |= PVSCSI_FLAG_CMD_WITH_SG_LIST;
373 			ctx->sglPA = dma_map_single(&adapter->dev->dev,
374 					ctx->sgl, SGL_SIZE, DMA_TO_DEVICE);
375 			if (dma_mapping_error(&adapter->dev->dev, ctx->sglPA)) {
376 				scmd_printk(KERN_ERR, cmd,
377 					    "vmw_pvscsi: Failed to map ctx sglist for DMA.\n");
378 				scsi_dma_unmap(cmd);
379 				ctx->sglPA = 0;
380 				return -ENOMEM;
381 			}
382 			e->dataAddr = ctx->sglPA;
383 		} else
384 			e->dataAddr = sg_dma_address(sg);
385 	} else {
386 		/*
387 		 * In case there is no S/G list, scsi_sglist points
388 		 * directly to the buffer.
389 		 */
390 		ctx->dataPA = dma_map_single(&adapter->dev->dev, sg, bufflen,
391 					     cmd->sc_data_direction);
392 		if (dma_mapping_error(&adapter->dev->dev, ctx->dataPA)) {
393 			scmd_printk(KERN_DEBUG, cmd,
394 				    "vmw_pvscsi: Failed to map direct data buffer for DMA.\n");
395 			return -ENOMEM;
396 		}
397 		e->dataAddr = ctx->dataPA;
398 	}
399 
400 	return 0;
401 }
402 
403 /*
404  * The device incorrectly doesn't clear the first byte of the sense
405  * buffer in some cases. We have to do it ourselves.
406  * Otherwise we run into trouble when SWIOTLB is forced.
407  */
408 static void pvscsi_patch_sense(struct scsi_cmnd *cmd)
409 {
410 	if (cmd->sense_buffer)
411 		cmd->sense_buffer[0] = 0;
412 }
413 
414 static void pvscsi_unmap_buffers(const struct pvscsi_adapter *adapter,
415 				 struct pvscsi_ctx *ctx)
416 {
417 	struct scsi_cmnd *cmd;
418 	unsigned bufflen;
419 
420 	cmd = ctx->cmd;
421 	bufflen = scsi_bufflen(cmd);
422 
423 	if (bufflen != 0) {
424 		unsigned count = scsi_sg_count(cmd);
425 
426 		if (count != 0) {
427 			scsi_dma_unmap(cmd);
428 			if (ctx->sglPA) {
429 				dma_unmap_single(&adapter->dev->dev, ctx->sglPA,
430 						 SGL_SIZE, DMA_TO_DEVICE);
431 				ctx->sglPA = 0;
432 			}
433 		} else
434 			dma_unmap_single(&adapter->dev->dev, ctx->dataPA,
435 					 bufflen, cmd->sc_data_direction);
436 	}
437 	if (cmd->sense_buffer)
438 		dma_unmap_single(&adapter->dev->dev, ctx->sensePA,
439 				 SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
440 }
441 
442 static int pvscsi_allocate_rings(struct pvscsi_adapter *adapter)
443 {
444 	adapter->rings_state = dma_alloc_coherent(&adapter->dev->dev, PAGE_SIZE,
445 			&adapter->ringStatePA, GFP_KERNEL);
446 	if (!adapter->rings_state)
447 		return -ENOMEM;
448 
449 	adapter->req_pages = min(PVSCSI_MAX_NUM_PAGES_REQ_RING,
450 				 pvscsi_ring_pages);
451 	adapter->req_depth = adapter->req_pages
452 					* PVSCSI_MAX_NUM_REQ_ENTRIES_PER_PAGE;
453 	adapter->req_ring = dma_alloc_coherent(&adapter->dev->dev,
454 			adapter->req_pages * PAGE_SIZE, &adapter->reqRingPA,
455 			GFP_KERNEL);
456 	if (!adapter->req_ring)
457 		return -ENOMEM;
458 
459 	adapter->cmp_pages = min(PVSCSI_MAX_NUM_PAGES_CMP_RING,
460 				 pvscsi_ring_pages);
461 	adapter->cmp_ring = dma_alloc_coherent(&adapter->dev->dev,
462 			adapter->cmp_pages * PAGE_SIZE, &adapter->cmpRingPA,
463 			GFP_KERNEL);
464 	if (!adapter->cmp_ring)
465 		return -ENOMEM;
466 
467 	BUG_ON(!IS_ALIGNED(adapter->ringStatePA, PAGE_SIZE));
468 	BUG_ON(!IS_ALIGNED(adapter->reqRingPA, PAGE_SIZE));
469 	BUG_ON(!IS_ALIGNED(adapter->cmpRingPA, PAGE_SIZE));
470 
471 	if (!adapter->use_msg)
472 		return 0;
473 
474 	adapter->msg_pages = min(PVSCSI_MAX_NUM_PAGES_MSG_RING,
475 				 pvscsi_msg_ring_pages);
476 	adapter->msg_ring = dma_alloc_coherent(&adapter->dev->dev,
477 			adapter->msg_pages * PAGE_SIZE, &adapter->msgRingPA,
478 			GFP_KERNEL);
479 	if (!adapter->msg_ring)
480 		return -ENOMEM;
481 	BUG_ON(!IS_ALIGNED(adapter->msgRingPA, PAGE_SIZE));
482 
483 	return 0;
484 }
485 
486 static void pvscsi_setup_all_rings(const struct pvscsi_adapter *adapter)
487 {
488 	struct PVSCSICmdDescSetupRings cmd = { 0 };
489 	dma_addr_t base;
490 	unsigned i;
491 
492 	cmd.ringsStatePPN   = adapter->ringStatePA >> PAGE_SHIFT;
493 	cmd.reqRingNumPages = adapter->req_pages;
494 	cmd.cmpRingNumPages = adapter->cmp_pages;
495 
496 	base = adapter->reqRingPA;
497 	for (i = 0; i < adapter->req_pages; i++) {
498 		cmd.reqRingPPNs[i] = base >> PAGE_SHIFT;
499 		base += PAGE_SIZE;
500 	}
501 
502 	base = adapter->cmpRingPA;
503 	for (i = 0; i < adapter->cmp_pages; i++) {
504 		cmd.cmpRingPPNs[i] = base >> PAGE_SHIFT;
505 		base += PAGE_SIZE;
506 	}
507 
508 	memset(adapter->rings_state, 0, PAGE_SIZE);
509 	memset(adapter->req_ring, 0, adapter->req_pages * PAGE_SIZE);
510 	memset(adapter->cmp_ring, 0, adapter->cmp_pages * PAGE_SIZE);
511 
512 	pvscsi_write_cmd_desc(adapter, PVSCSI_CMD_SETUP_RINGS,
513 			      &cmd, sizeof(cmd));
514 
515 	if (adapter->use_msg) {
516 		struct PVSCSICmdDescSetupMsgRing cmd_msg = { 0 };
517 
518 		cmd_msg.numPages = adapter->msg_pages;
519 
520 		base = adapter->msgRingPA;
521 		for (i = 0; i < adapter->msg_pages; i++) {
522 			cmd_msg.ringPPNs[i] = base >> PAGE_SHIFT;
523 			base += PAGE_SIZE;
524 		}
525 		memset(adapter->msg_ring, 0, adapter->msg_pages * PAGE_SIZE);
526 
527 		pvscsi_write_cmd_desc(adapter, PVSCSI_CMD_SETUP_MSG_RING,
528 				      &cmd_msg, sizeof(cmd_msg));
529 	}
530 }
531 
532 static int pvscsi_change_queue_depth(struct scsi_device *sdev, int qdepth)
533 {
534 	if (!sdev->tagged_supported)
535 		qdepth = 1;
536 	return scsi_change_queue_depth(sdev, qdepth);
537 }
538 
539 /*
540  * Pull a completion descriptor off and pass the completion back
541  * to the SCSI mid layer.
542  */
543 static void pvscsi_complete_request(struct pvscsi_adapter *adapter,
544 				    const struct PVSCSIRingCmpDesc *e)
545 {
546 	struct pvscsi_ctx *ctx;
547 	struct scsi_cmnd *cmd;
548 	struct completion *abort_cmp;
549 	u32 btstat = e->hostStatus;
550 	u32 sdstat = e->scsiStatus;
551 
552 	ctx = pvscsi_get_context(adapter, e->context);
553 	cmd = ctx->cmd;
554 	abort_cmp = ctx->abort_cmp;
555 	pvscsi_unmap_buffers(adapter, ctx);
556 	if (sdstat != SAM_STAT_CHECK_CONDITION)
557 		pvscsi_patch_sense(cmd);
558 	pvscsi_release_context(adapter, ctx);
559 	if (abort_cmp) {
560 		/*
561 		 * The command was requested to be aborted. Just signal that
562 		 * the request completed and swallow the actual cmd completion
563 		 * here. The abort handler will post a completion for this
564 		 * command indicating that it got successfully aborted.
565 		 */
566 		complete(abort_cmp);
567 		return;
568 	}
569 
570 	cmd->result = 0;
571 	if (sdstat != SAM_STAT_GOOD &&
572 	    (btstat == BTSTAT_SUCCESS ||
573 	     btstat == BTSTAT_LINKED_COMMAND_COMPLETED ||
574 	     btstat == BTSTAT_LINKED_COMMAND_COMPLETED_WITH_FLAG)) {
575 		if (sdstat == SAM_STAT_COMMAND_TERMINATED) {
576 			cmd->result = (DID_RESET << 16);
577 		} else {
578 			cmd->result = (DID_OK << 16) | sdstat;
579 		}
580 	} else
581 		switch (btstat) {
582 		case BTSTAT_SUCCESS:
583 		case BTSTAT_LINKED_COMMAND_COMPLETED:
584 		case BTSTAT_LINKED_COMMAND_COMPLETED_WITH_FLAG:
585 			/*
586 			 * Commands like INQUIRY may transfer less data than
587 			 * requested by the initiator via bufflen. Set residual
588 			 * count to make upper layer aware of the actual amount
589 			 * of data returned. There are cases when controller
590 			 * returns zero dataLen with non zero data - do not set
591 			 * residual count in that case.
592 			 */
593 			if (e->dataLen && (e->dataLen < scsi_bufflen(cmd)))
594 				scsi_set_resid(cmd, scsi_bufflen(cmd) - e->dataLen);
595 			cmd->result = (DID_OK << 16);
596 			break;
597 
598 		case BTSTAT_DATARUN:
599 		case BTSTAT_DATA_UNDERRUN:
600 			/* Report residual data in underruns */
601 			scsi_set_resid(cmd, scsi_bufflen(cmd) - e->dataLen);
602 			cmd->result = (DID_ERROR << 16);
603 			break;
604 
605 		case BTSTAT_SELTIMEO:
606 			/* Our emulation returns this for non-connected devs */
607 			cmd->result = (DID_BAD_TARGET << 16);
608 			break;
609 
610 		case BTSTAT_LUNMISMATCH:
611 		case BTSTAT_TAGREJECT:
612 		case BTSTAT_BADMSG:
613 		case BTSTAT_HAHARDWARE:
614 		case BTSTAT_INVPHASE:
615 		case BTSTAT_HATIMEOUT:
616 		case BTSTAT_NORESPONSE:
617 		case BTSTAT_DISCONNECT:
618 		case BTSTAT_HASOFTWARE:
619 		case BTSTAT_BUSFREE:
620 		case BTSTAT_SENSFAILED:
621 			cmd->result |= (DID_ERROR << 16);
622 			break;
623 
624 		case BTSTAT_SENTRST:
625 		case BTSTAT_RECVRST:
626 		case BTSTAT_BUSRESET:
627 			cmd->result = (DID_RESET << 16);
628 			break;
629 
630 		case BTSTAT_ABORTQUEUE:
631 			cmd->result = (DID_BUS_BUSY << 16);
632 			break;
633 
634 		case BTSTAT_SCSIPARITY:
635 			cmd->result = (DID_PARITY << 16);
636 			break;
637 
638 		default:
639 			cmd->result = (DID_ERROR << 16);
640 			scmd_printk(KERN_DEBUG, cmd,
641 				    "Unknown completion status: 0x%x\n",
642 				    btstat);
643 	}
644 
645 	dev_dbg(&cmd->device->sdev_gendev,
646 		"cmd=%p %x ctx=%p result=0x%x status=0x%x,%x\n",
647 		cmd, cmd->cmnd[0], ctx, cmd->result, btstat, sdstat);
648 
649 	scsi_done(cmd);
650 }
651 
652 /*
653  * barrier usage : Since the PVSCSI device is emulated, there could be cases
654  * where we may want to serialize some accesses between the driver and the
655  * emulation layer. We use compiler barriers instead of the more expensive
656  * memory barriers because PVSCSI is only supported on X86 which has strong
657  * memory access ordering.
658  */
659 static void pvscsi_process_completion_ring(struct pvscsi_adapter *adapter)
660 {
661 	struct PVSCSIRingsState *s = adapter->rings_state;
662 	struct PVSCSIRingCmpDesc *ring = adapter->cmp_ring;
663 	u32 cmp_entries = s->cmpNumEntriesLog2;
664 
665 	while (s->cmpConsIdx != s->cmpProdIdx) {
666 		struct PVSCSIRingCmpDesc *e = ring + (s->cmpConsIdx &
667 						      MASK(cmp_entries));
668 		/*
669 		 * This barrier() ensures that *e is not dereferenced while
670 		 * the device emulation still writes data into the slot.
671 		 * Since the device emulation advances s->cmpProdIdx only after
672 		 * updating the slot we want to check it first.
673 		 */
674 		barrier();
675 		pvscsi_complete_request(adapter, e);
676 		/*
677 		 * This barrier() ensures that compiler doesn't reorder write
678 		 * to s->cmpConsIdx before the read of (*e) inside
679 		 * pvscsi_complete_request. Otherwise, device emulation may
680 		 * overwrite *e before we had a chance to read it.
681 		 */
682 		barrier();
683 		s->cmpConsIdx++;
684 	}
685 }
686 
687 /*
688  * Translate a Linux SCSI request into a request ring entry.
689  */
690 static int pvscsi_queue_ring(struct pvscsi_adapter *adapter,
691 			     struct pvscsi_ctx *ctx, struct scsi_cmnd *cmd)
692 {
693 	struct PVSCSIRingsState *s;
694 	struct PVSCSIRingReqDesc *e;
695 	struct scsi_device *sdev;
696 	u32 req_entries;
697 
698 	s = adapter->rings_state;
699 	sdev = cmd->device;
700 	req_entries = s->reqNumEntriesLog2;
701 
702 	/*
703 	 * If this condition holds, we might have room on the request ring, but
704 	 * we might not have room on the completion ring for the response.
705 	 * However, we have already ruled out this possibility - we would not
706 	 * have successfully allocated a context if it were true, since we only
707 	 * have one context per request entry.  Check for it anyway, since it
708 	 * would be a serious bug.
709 	 */
710 	if (s->reqProdIdx - s->cmpConsIdx >= 1 << req_entries) {
711 		scmd_printk(KERN_ERR, cmd, "vmw_pvscsi: "
712 			    "ring full: reqProdIdx=%d cmpConsIdx=%d\n",
713 			    s->reqProdIdx, s->cmpConsIdx);
714 		return -1;
715 	}
716 
717 	e = adapter->req_ring + (s->reqProdIdx & MASK(req_entries));
718 
719 	e->bus    = sdev->channel;
720 	e->target = sdev->id;
721 	memset(e->lun, 0, sizeof(e->lun));
722 	e->lun[1] = sdev->lun;
723 
724 	if (cmd->sense_buffer) {
725 		ctx->sensePA = dma_map_single(&adapter->dev->dev,
726 				cmd->sense_buffer, SCSI_SENSE_BUFFERSIZE,
727 				DMA_FROM_DEVICE);
728 		if (dma_mapping_error(&adapter->dev->dev, ctx->sensePA)) {
729 			scmd_printk(KERN_DEBUG, cmd,
730 				    "vmw_pvscsi: Failed to map sense buffer for DMA.\n");
731 			ctx->sensePA = 0;
732 			return -ENOMEM;
733 		}
734 		e->senseAddr = ctx->sensePA;
735 		e->senseLen = SCSI_SENSE_BUFFERSIZE;
736 	} else {
737 		e->senseLen  = 0;
738 		e->senseAddr = 0;
739 	}
740 	e->cdbLen   = cmd->cmd_len;
741 	e->vcpuHint = smp_processor_id();
742 	memcpy(e->cdb, cmd->cmnd, e->cdbLen);
743 
744 	e->tag = SIMPLE_QUEUE_TAG;
745 
746 	if (cmd->sc_data_direction == DMA_FROM_DEVICE)
747 		e->flags = PVSCSI_FLAG_CMD_DIR_TOHOST;
748 	else if (cmd->sc_data_direction == DMA_TO_DEVICE)
749 		e->flags = PVSCSI_FLAG_CMD_DIR_TODEVICE;
750 	else if (cmd->sc_data_direction == DMA_NONE)
751 		e->flags = PVSCSI_FLAG_CMD_DIR_NONE;
752 	else
753 		e->flags = 0;
754 
755 	if (pvscsi_map_buffers(adapter, ctx, cmd, e) != 0) {
756 		if (cmd->sense_buffer) {
757 			dma_unmap_single(&adapter->dev->dev, ctx->sensePA,
758 					 SCSI_SENSE_BUFFERSIZE,
759 					 DMA_FROM_DEVICE);
760 			ctx->sensePA = 0;
761 		}
762 		return -ENOMEM;
763 	}
764 
765 	e->context = pvscsi_map_context(adapter, ctx);
766 
767 	barrier();
768 
769 	s->reqProdIdx++;
770 
771 	return 0;
772 }
773 
774 static int pvscsi_queue_lck(struct scsi_cmnd *cmd)
775 {
776 	struct Scsi_Host *host = cmd->device->host;
777 	struct pvscsi_adapter *adapter = shost_priv(host);
778 	struct pvscsi_ctx *ctx;
779 	unsigned long flags;
780 	unsigned char op;
781 
782 	spin_lock_irqsave(&adapter->hw_lock, flags);
783 
784 	ctx = pvscsi_acquire_context(adapter, cmd);
785 	if (!ctx || pvscsi_queue_ring(adapter, ctx, cmd) != 0) {
786 		if (ctx)
787 			pvscsi_release_context(adapter, ctx);
788 		spin_unlock_irqrestore(&adapter->hw_lock, flags);
789 		return SCSI_MLQUEUE_HOST_BUSY;
790 	}
791 
792 	op = cmd->cmnd[0];
793 
794 	dev_dbg(&cmd->device->sdev_gendev,
795 		"queued cmd %p, ctx %p, op=%x\n", cmd, ctx, op);
796 
797 	spin_unlock_irqrestore(&adapter->hw_lock, flags);
798 
799 	pvscsi_kick_io(adapter, op);
800 
801 	return 0;
802 }
803 
804 static DEF_SCSI_QCMD(pvscsi_queue)
805 
806 static int pvscsi_abort(struct scsi_cmnd *cmd)
807 {
808 	struct pvscsi_adapter *adapter = shost_priv(cmd->device->host);
809 	struct pvscsi_ctx *ctx;
810 	unsigned long flags;
811 	int result = SUCCESS;
812 	DECLARE_COMPLETION_ONSTACK(abort_cmp);
813 	int done;
814 
815 	scmd_printk(KERN_DEBUG, cmd, "task abort on host %u, %p\n",
816 		    adapter->host->host_no, cmd);
817 
818 	spin_lock_irqsave(&adapter->hw_lock, flags);
819 
820 	/*
821 	 * Poll the completion ring first - we might be trying to abort
822 	 * a command that is waiting to be dispatched in the completion ring.
823 	 */
824 	pvscsi_process_completion_ring(adapter);
825 
826 	/*
827 	 * If there is no context for the command, it either already succeeded
828 	 * or else was never properly issued.  Not our problem.
829 	 */
830 	ctx = pvscsi_find_context(adapter, cmd);
831 	if (!ctx) {
832 		scmd_printk(KERN_DEBUG, cmd, "Failed to abort cmd %p\n", cmd);
833 		goto out;
834 	}
835 
836 	/*
837 	 * Mark that the command has been requested to be aborted and issue
838 	 * the abort.
839 	 */
840 	ctx->abort_cmp = &abort_cmp;
841 
842 	pvscsi_abort_cmd(adapter, ctx);
843 	spin_unlock_irqrestore(&adapter->hw_lock, flags);
844 	/* Wait for 2 secs for the completion. */
845 	done = wait_for_completion_timeout(&abort_cmp, msecs_to_jiffies(2000));
846 	spin_lock_irqsave(&adapter->hw_lock, flags);
847 
848 	if (!done) {
849 		/*
850 		 * Failed to abort the command, unmark the fact that it
851 		 * was requested to be aborted.
852 		 */
853 		ctx->abort_cmp = NULL;
854 		result = FAILED;
855 		scmd_printk(KERN_DEBUG, cmd,
856 			    "Failed to get completion for aborted cmd %p\n",
857 			    cmd);
858 		goto out;
859 	}
860 
861 	/*
862 	 * Successfully aborted the command.
863 	 */
864 	cmd->result = (DID_ABORT << 16);
865 	scsi_done(cmd);
866 
867 out:
868 	spin_unlock_irqrestore(&adapter->hw_lock, flags);
869 	return result;
870 }
871 
872 /*
873  * Abort all outstanding requests.  This is only safe to use if the completion
874  * ring will never be walked again or the device has been reset, because it
875  * destroys the 1-1 mapping between context field passed to emulation and our
876  * request structure.
877  */
878 static void pvscsi_reset_all(struct pvscsi_adapter *adapter)
879 {
880 	unsigned i;
881 
882 	for (i = 0; i < adapter->req_depth; i++) {
883 		struct pvscsi_ctx *ctx = &adapter->cmd_map[i];
884 		struct scsi_cmnd *cmd = ctx->cmd;
885 		if (cmd) {
886 			scmd_printk(KERN_ERR, cmd,
887 				    "Forced reset on cmd %p\n", cmd);
888 			pvscsi_unmap_buffers(adapter, ctx);
889 			pvscsi_patch_sense(cmd);
890 			pvscsi_release_context(adapter, ctx);
891 			cmd->result = (DID_RESET << 16);
892 			scsi_done(cmd);
893 		}
894 	}
895 }
896 
897 static int pvscsi_host_reset(struct scsi_cmnd *cmd)
898 {
899 	struct Scsi_Host *host = cmd->device->host;
900 	struct pvscsi_adapter *adapter = shost_priv(host);
901 	unsigned long flags;
902 	bool use_msg;
903 
904 	scmd_printk(KERN_INFO, cmd, "SCSI Host reset\n");
905 
906 	spin_lock_irqsave(&adapter->hw_lock, flags);
907 
908 	use_msg = adapter->use_msg;
909 
910 	if (use_msg) {
911 		adapter->use_msg = false;
912 		spin_unlock_irqrestore(&adapter->hw_lock, flags);
913 
914 		/*
915 		 * Now that we know that the ISR won't add more work on the
916 		 * workqueue we can safely flush any outstanding work.
917 		 */
918 		flush_workqueue(adapter->workqueue);
919 		spin_lock_irqsave(&adapter->hw_lock, flags);
920 	}
921 
922 	/*
923 	 * We're going to tear down the entire ring structure and set it back
924 	 * up, so stalling new requests until all completions are flushed and
925 	 * the rings are back in place.
926 	 */
927 
928 	pvscsi_process_request_ring(adapter);
929 
930 	ll_adapter_reset(adapter);
931 
932 	/*
933 	 * Now process any completions.  Note we do this AFTER adapter reset,
934 	 * which is strange, but stops races where completions get posted
935 	 * between processing the ring and issuing the reset.  The backend will
936 	 * not touch the ring memory after reset, so the immediately pre-reset
937 	 * completion ring state is still valid.
938 	 */
939 	pvscsi_process_completion_ring(adapter);
940 
941 	pvscsi_reset_all(adapter);
942 	adapter->use_msg = use_msg;
943 	pvscsi_setup_all_rings(adapter);
944 	pvscsi_unmask_intr(adapter);
945 
946 	spin_unlock_irqrestore(&adapter->hw_lock, flags);
947 
948 	return SUCCESS;
949 }
950 
951 static int pvscsi_bus_reset(struct scsi_cmnd *cmd)
952 {
953 	struct Scsi_Host *host = cmd->device->host;
954 	struct pvscsi_adapter *adapter = shost_priv(host);
955 	unsigned long flags;
956 
957 	scmd_printk(KERN_INFO, cmd, "SCSI Bus reset\n");
958 
959 	/*
960 	 * We don't want to queue new requests for this bus after
961 	 * flushing all pending requests to emulation, since new
962 	 * requests could then sneak in during this bus reset phase,
963 	 * so take the lock now.
964 	 */
965 	spin_lock_irqsave(&adapter->hw_lock, flags);
966 
967 	pvscsi_process_request_ring(adapter);
968 	ll_bus_reset(adapter);
969 	pvscsi_process_completion_ring(adapter);
970 
971 	spin_unlock_irqrestore(&adapter->hw_lock, flags);
972 
973 	return SUCCESS;
974 }
975 
976 static int pvscsi_device_reset(struct scsi_cmnd *cmd)
977 {
978 	struct Scsi_Host *host = cmd->device->host;
979 	struct pvscsi_adapter *adapter = shost_priv(host);
980 	unsigned long flags;
981 
982 	scmd_printk(KERN_INFO, cmd, "SCSI device reset on scsi%u:%u\n",
983 		    host->host_no, cmd->device->id);
984 
985 	/*
986 	 * We don't want to queue new requests for this device after flushing
987 	 * all pending requests to emulation, since new requests could then
988 	 * sneak in during this device reset phase, so take the lock now.
989 	 */
990 	spin_lock_irqsave(&adapter->hw_lock, flags);
991 
992 	pvscsi_process_request_ring(adapter);
993 	ll_device_reset(adapter, cmd->device->id);
994 	pvscsi_process_completion_ring(adapter);
995 
996 	spin_unlock_irqrestore(&adapter->hw_lock, flags);
997 
998 	return SUCCESS;
999 }
1000 
1001 static struct scsi_host_template pvscsi_template;
1002 
1003 static const char *pvscsi_info(struct Scsi_Host *host)
1004 {
1005 	struct pvscsi_adapter *adapter = shost_priv(host);
1006 	static char buf[256];
1007 
1008 	sprintf(buf, "VMware PVSCSI storage adapter rev %d, req/cmp/msg rings: "
1009 		"%u/%u/%u pages, cmd_per_lun=%u", adapter->rev,
1010 		adapter->req_pages, adapter->cmp_pages, adapter->msg_pages,
1011 		pvscsi_template.cmd_per_lun);
1012 
1013 	return buf;
1014 }
1015 
1016 static struct scsi_host_template pvscsi_template = {
1017 	.module				= THIS_MODULE,
1018 	.name				= "VMware PVSCSI Host Adapter",
1019 	.proc_name			= "vmw_pvscsi",
1020 	.info				= pvscsi_info,
1021 	.queuecommand			= pvscsi_queue,
1022 	.this_id			= -1,
1023 	.sg_tablesize			= PVSCSI_MAX_NUM_SG_ENTRIES_PER_SEGMENT,
1024 	.dma_boundary			= UINT_MAX,
1025 	.max_sectors			= 0xffff,
1026 	.change_queue_depth		= pvscsi_change_queue_depth,
1027 	.eh_abort_handler		= pvscsi_abort,
1028 	.eh_device_reset_handler	= pvscsi_device_reset,
1029 	.eh_bus_reset_handler		= pvscsi_bus_reset,
1030 	.eh_host_reset_handler		= pvscsi_host_reset,
1031 };
1032 
1033 static void pvscsi_process_msg(const struct pvscsi_adapter *adapter,
1034 			       const struct PVSCSIRingMsgDesc *e)
1035 {
1036 	struct PVSCSIRingsState *s = adapter->rings_state;
1037 	struct Scsi_Host *host = adapter->host;
1038 	struct scsi_device *sdev;
1039 
1040 	printk(KERN_INFO "vmw_pvscsi: msg type: 0x%x - MSG RING: %u/%u (%u) \n",
1041 	       e->type, s->msgProdIdx, s->msgConsIdx, s->msgNumEntriesLog2);
1042 
1043 	BUILD_BUG_ON(PVSCSI_MSG_LAST != 2);
1044 
1045 	if (e->type == PVSCSI_MSG_DEV_ADDED) {
1046 		struct PVSCSIMsgDescDevStatusChanged *desc;
1047 		desc = (struct PVSCSIMsgDescDevStatusChanged *)e;
1048 
1049 		printk(KERN_INFO
1050 		       "vmw_pvscsi: msg: device added at scsi%u:%u:%u\n",
1051 		       desc->bus, desc->target, desc->lun[1]);
1052 
1053 		if (!scsi_host_get(host))
1054 			return;
1055 
1056 		sdev = scsi_device_lookup(host, desc->bus, desc->target,
1057 					  desc->lun[1]);
1058 		if (sdev) {
1059 			printk(KERN_INFO "vmw_pvscsi: device already exists\n");
1060 			scsi_device_put(sdev);
1061 		} else
1062 			scsi_add_device(adapter->host, desc->bus,
1063 					desc->target, desc->lun[1]);
1064 
1065 		scsi_host_put(host);
1066 	} else if (e->type == PVSCSI_MSG_DEV_REMOVED) {
1067 		struct PVSCSIMsgDescDevStatusChanged *desc;
1068 		desc = (struct PVSCSIMsgDescDevStatusChanged *)e;
1069 
1070 		printk(KERN_INFO
1071 		       "vmw_pvscsi: msg: device removed at scsi%u:%u:%u\n",
1072 		       desc->bus, desc->target, desc->lun[1]);
1073 
1074 		if (!scsi_host_get(host))
1075 			return;
1076 
1077 		sdev = scsi_device_lookup(host, desc->bus, desc->target,
1078 					  desc->lun[1]);
1079 		if (sdev) {
1080 			scsi_remove_device(sdev);
1081 			scsi_device_put(sdev);
1082 		} else
1083 			printk(KERN_INFO
1084 			       "vmw_pvscsi: failed to lookup scsi%u:%u:%u\n",
1085 			       desc->bus, desc->target, desc->lun[1]);
1086 
1087 		scsi_host_put(host);
1088 	}
1089 }
1090 
1091 static int pvscsi_msg_pending(const struct pvscsi_adapter *adapter)
1092 {
1093 	struct PVSCSIRingsState *s = adapter->rings_state;
1094 
1095 	return s->msgProdIdx != s->msgConsIdx;
1096 }
1097 
1098 static void pvscsi_process_msg_ring(const struct pvscsi_adapter *adapter)
1099 {
1100 	struct PVSCSIRingsState *s = adapter->rings_state;
1101 	struct PVSCSIRingMsgDesc *ring = adapter->msg_ring;
1102 	u32 msg_entries = s->msgNumEntriesLog2;
1103 
1104 	while (pvscsi_msg_pending(adapter)) {
1105 		struct PVSCSIRingMsgDesc *e = ring + (s->msgConsIdx &
1106 						      MASK(msg_entries));
1107 
1108 		barrier();
1109 		pvscsi_process_msg(adapter, e);
1110 		barrier();
1111 		s->msgConsIdx++;
1112 	}
1113 }
1114 
1115 static void pvscsi_msg_workqueue_handler(struct work_struct *data)
1116 {
1117 	struct pvscsi_adapter *adapter;
1118 
1119 	adapter = container_of(data, struct pvscsi_adapter, work);
1120 
1121 	pvscsi_process_msg_ring(adapter);
1122 }
1123 
1124 static int pvscsi_setup_msg_workqueue(struct pvscsi_adapter *adapter)
1125 {
1126 	char name[32];
1127 
1128 	if (!pvscsi_use_msg)
1129 		return 0;
1130 
1131 	pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_COMMAND,
1132 			 PVSCSI_CMD_SETUP_MSG_RING);
1133 
1134 	if (pvscsi_reg_read(adapter, PVSCSI_REG_OFFSET_COMMAND_STATUS) == -1)
1135 		return 0;
1136 
1137 	snprintf(name, sizeof(name),
1138 		 "vmw_pvscsi_wq_%u", adapter->host->host_no);
1139 
1140 	adapter->workqueue = create_singlethread_workqueue(name);
1141 	if (!adapter->workqueue) {
1142 		printk(KERN_ERR "vmw_pvscsi: failed to create work queue\n");
1143 		return 0;
1144 	}
1145 	INIT_WORK(&adapter->work, pvscsi_msg_workqueue_handler);
1146 
1147 	return 1;
1148 }
1149 
1150 static bool pvscsi_setup_req_threshold(struct pvscsi_adapter *adapter,
1151 				      bool enable)
1152 {
1153 	u32 val;
1154 
1155 	if (!pvscsi_use_req_threshold)
1156 		return false;
1157 
1158 	pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_COMMAND,
1159 			 PVSCSI_CMD_SETUP_REQCALLTHRESHOLD);
1160 	val = pvscsi_reg_read(adapter, PVSCSI_REG_OFFSET_COMMAND_STATUS);
1161 	if (val == -1) {
1162 		printk(KERN_INFO "vmw_pvscsi: device does not support req_threshold\n");
1163 		return false;
1164 	} else {
1165 		struct PVSCSICmdDescSetupReqCall cmd_msg = { 0 };
1166 		cmd_msg.enable = enable;
1167 		printk(KERN_INFO
1168 		       "vmw_pvscsi: %sabling reqCallThreshold\n",
1169 			enable ? "en" : "dis");
1170 		pvscsi_write_cmd_desc(adapter,
1171 				      PVSCSI_CMD_SETUP_REQCALLTHRESHOLD,
1172 				      &cmd_msg, sizeof(cmd_msg));
1173 		return pvscsi_reg_read(adapter,
1174 				       PVSCSI_REG_OFFSET_COMMAND_STATUS) != 0;
1175 	}
1176 }
1177 
1178 static irqreturn_t pvscsi_isr(int irq, void *devp)
1179 {
1180 	struct pvscsi_adapter *adapter = devp;
1181 	unsigned long flags;
1182 
1183 	spin_lock_irqsave(&adapter->hw_lock, flags);
1184 	pvscsi_process_completion_ring(adapter);
1185 	if (adapter->use_msg && pvscsi_msg_pending(adapter))
1186 		queue_work(adapter->workqueue, &adapter->work);
1187 	spin_unlock_irqrestore(&adapter->hw_lock, flags);
1188 
1189 	return IRQ_HANDLED;
1190 }
1191 
1192 static irqreturn_t pvscsi_shared_isr(int irq, void *devp)
1193 {
1194 	struct pvscsi_adapter *adapter = devp;
1195 	u32 val = pvscsi_read_intr_status(adapter);
1196 
1197 	if (!(val & PVSCSI_INTR_ALL_SUPPORTED))
1198 		return IRQ_NONE;
1199 	pvscsi_write_intr_status(devp, val);
1200 	return pvscsi_isr(irq, devp);
1201 }
1202 
1203 static void pvscsi_free_sgls(const struct pvscsi_adapter *adapter)
1204 {
1205 	struct pvscsi_ctx *ctx = adapter->cmd_map;
1206 	unsigned i;
1207 
1208 	for (i = 0; i < adapter->req_depth; ++i, ++ctx)
1209 		free_pages((unsigned long)ctx->sgl, get_order(SGL_SIZE));
1210 }
1211 
1212 static void pvscsi_shutdown_intr(struct pvscsi_adapter *adapter)
1213 {
1214 	free_irq(pci_irq_vector(adapter->dev, 0), adapter);
1215 	pci_free_irq_vectors(adapter->dev);
1216 }
1217 
1218 static void pvscsi_release_resources(struct pvscsi_adapter *adapter)
1219 {
1220 	if (adapter->workqueue)
1221 		destroy_workqueue(adapter->workqueue);
1222 
1223 	if (adapter->mmioBase)
1224 		pci_iounmap(adapter->dev, adapter->mmioBase);
1225 
1226 	pci_release_regions(adapter->dev);
1227 
1228 	if (adapter->cmd_map) {
1229 		pvscsi_free_sgls(adapter);
1230 		kfree(adapter->cmd_map);
1231 	}
1232 
1233 	if (adapter->rings_state)
1234 		dma_free_coherent(&adapter->dev->dev, PAGE_SIZE,
1235 				    adapter->rings_state, adapter->ringStatePA);
1236 
1237 	if (adapter->req_ring)
1238 		dma_free_coherent(&adapter->dev->dev,
1239 				    adapter->req_pages * PAGE_SIZE,
1240 				    adapter->req_ring, adapter->reqRingPA);
1241 
1242 	if (adapter->cmp_ring)
1243 		dma_free_coherent(&adapter->dev->dev,
1244 				    adapter->cmp_pages * PAGE_SIZE,
1245 				    adapter->cmp_ring, adapter->cmpRingPA);
1246 
1247 	if (adapter->msg_ring)
1248 		dma_free_coherent(&adapter->dev->dev,
1249 				    adapter->msg_pages * PAGE_SIZE,
1250 				    adapter->msg_ring, adapter->msgRingPA);
1251 }
1252 
1253 /*
1254  * Allocate scatter gather lists.
1255  *
1256  * These are statically allocated.  Trying to be clever was not worth it.
1257  *
1258  * Dynamic allocation can fail, and we can't go deep into the memory
1259  * allocator, since we're a SCSI driver, and trying too hard to allocate
1260  * memory might generate disk I/O.  We also don't want to fail disk I/O
1261  * in that case because we can't get an allocation - the I/O could be
1262  * trying to swap out data to free memory.  Since that is pathological,
1263  * just use a statically allocated scatter list.
1264  *
1265  */
1266 static int pvscsi_allocate_sg(struct pvscsi_adapter *adapter)
1267 {
1268 	struct pvscsi_ctx *ctx;
1269 	int i;
1270 
1271 	ctx = adapter->cmd_map;
1272 	BUILD_BUG_ON(sizeof(struct pvscsi_sg_list) > SGL_SIZE);
1273 
1274 	for (i = 0; i < adapter->req_depth; ++i, ++ctx) {
1275 		ctx->sgl = (void *)__get_free_pages(GFP_KERNEL,
1276 						    get_order(SGL_SIZE));
1277 		ctx->sglPA = 0;
1278 		BUG_ON(!IS_ALIGNED(((unsigned long)ctx->sgl), PAGE_SIZE));
1279 		if (!ctx->sgl) {
1280 			for (; i >= 0; --i, --ctx) {
1281 				free_pages((unsigned long)ctx->sgl,
1282 					   get_order(SGL_SIZE));
1283 				ctx->sgl = NULL;
1284 			}
1285 			return -ENOMEM;
1286 		}
1287 	}
1288 
1289 	return 0;
1290 }
1291 
1292 /*
1293  * Query the device, fetch the config info and return the
1294  * maximum number of targets on the adapter. In case of
1295  * failure due to any reason return default i.e. 16.
1296  */
1297 static u32 pvscsi_get_max_targets(struct pvscsi_adapter *adapter)
1298 {
1299 	struct PVSCSICmdDescConfigCmd cmd;
1300 	struct PVSCSIConfigPageHeader *header;
1301 	struct device *dev;
1302 	dma_addr_t configPagePA;
1303 	void *config_page;
1304 	u32 numPhys = 16;
1305 
1306 	dev = pvscsi_dev(adapter);
1307 	config_page = dma_alloc_coherent(&adapter->dev->dev, PAGE_SIZE,
1308 			&configPagePA, GFP_KERNEL);
1309 	if (!config_page) {
1310 		dev_warn(dev, "vmw_pvscsi: failed to allocate memory for config page\n");
1311 		goto exit;
1312 	}
1313 	BUG_ON(configPagePA & ~PAGE_MASK);
1314 
1315 	/* Fetch config info from the device. */
1316 	cmd.configPageAddress = ((u64)PVSCSI_CONFIG_CONTROLLER_ADDRESS) << 32;
1317 	cmd.configPageNum = PVSCSI_CONFIG_PAGE_CONTROLLER;
1318 	cmd.cmpAddr = configPagePA;
1319 	cmd._pad = 0;
1320 
1321 	/*
1322 	 * Mark the completion page header with error values. If the device
1323 	 * completes the command successfully, it sets the status values to
1324 	 * indicate success.
1325 	 */
1326 	header = config_page;
1327 	header->hostStatus = BTSTAT_INVPARAM;
1328 	header->scsiStatus = SDSTAT_CHECK;
1329 
1330 	pvscsi_write_cmd_desc(adapter, PVSCSI_CMD_CONFIG, &cmd, sizeof cmd);
1331 
1332 	if (header->hostStatus == BTSTAT_SUCCESS &&
1333 	    header->scsiStatus == SDSTAT_GOOD) {
1334 		struct PVSCSIConfigPageController *config;
1335 
1336 		config = config_page;
1337 		numPhys = config->numPhys;
1338 	} else
1339 		dev_warn(dev, "vmw_pvscsi: PVSCSI_CMD_CONFIG failed. hostStatus = 0x%x, scsiStatus = 0x%x\n",
1340 			 header->hostStatus, header->scsiStatus);
1341 	dma_free_coherent(&adapter->dev->dev, PAGE_SIZE, config_page,
1342 			  configPagePA);
1343 exit:
1344 	return numPhys;
1345 }
1346 
1347 static int pvscsi_probe(struct pci_dev *pdev, const struct pci_device_id *id)
1348 {
1349 	unsigned int irq_flag = PCI_IRQ_MSIX | PCI_IRQ_MSI | PCI_IRQ_LEGACY;
1350 	struct pvscsi_adapter *adapter;
1351 	struct pvscsi_adapter adapter_temp;
1352 	struct Scsi_Host *host = NULL;
1353 	unsigned int i;
1354 	int error;
1355 	u32 max_id;
1356 
1357 	error = -ENODEV;
1358 
1359 	if (pci_enable_device(pdev))
1360 		return error;
1361 
1362 	if (!dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64))) {
1363 		printk(KERN_INFO "vmw_pvscsi: using 64bit dma\n");
1364 	} else if (!dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32))) {
1365 		printk(KERN_INFO "vmw_pvscsi: using 32bit dma\n");
1366 	} else {
1367 		printk(KERN_ERR "vmw_pvscsi: failed to set DMA mask\n");
1368 		goto out_disable_device;
1369 	}
1370 
1371 	/*
1372 	 * Let's use a temp pvscsi_adapter struct until we find the number of
1373 	 * targets on the adapter, after that we will switch to the real
1374 	 * allocated struct.
1375 	 */
1376 	adapter = &adapter_temp;
1377 	memset(adapter, 0, sizeof(*adapter));
1378 	adapter->dev  = pdev;
1379 	adapter->rev = pdev->revision;
1380 
1381 	if (pci_request_regions(pdev, "vmw_pvscsi")) {
1382 		printk(KERN_ERR "vmw_pvscsi: pci memory selection failed\n");
1383 		goto out_disable_device;
1384 	}
1385 
1386 	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
1387 		if ((pci_resource_flags(pdev, i) & PCI_BASE_ADDRESS_SPACE_IO))
1388 			continue;
1389 
1390 		if (pci_resource_len(pdev, i) < PVSCSI_MEM_SPACE_SIZE)
1391 			continue;
1392 
1393 		break;
1394 	}
1395 
1396 	if (i == DEVICE_COUNT_RESOURCE) {
1397 		printk(KERN_ERR
1398 		       "vmw_pvscsi: adapter has no suitable MMIO region\n");
1399 		goto out_release_resources_and_disable;
1400 	}
1401 
1402 	adapter->mmioBase = pci_iomap(pdev, i, PVSCSI_MEM_SPACE_SIZE);
1403 
1404 	if (!adapter->mmioBase) {
1405 		printk(KERN_ERR
1406 		       "vmw_pvscsi: can't iomap for BAR %d memsize %lu\n",
1407 		       i, PVSCSI_MEM_SPACE_SIZE);
1408 		goto out_release_resources_and_disable;
1409 	}
1410 
1411 	pci_set_master(pdev);
1412 
1413 	/*
1414 	 * Ask the device for max number of targets before deciding the
1415 	 * default pvscsi_ring_pages value.
1416 	 */
1417 	max_id = pvscsi_get_max_targets(adapter);
1418 	printk(KERN_INFO "vmw_pvscsi: max_id: %u\n", max_id);
1419 
1420 	if (pvscsi_ring_pages == 0)
1421 		/*
1422 		 * Set the right default value. Up to 16 it is 8, above it is
1423 		 * max.
1424 		 */
1425 		pvscsi_ring_pages = (max_id > 16) ?
1426 			PVSCSI_SETUP_RINGS_MAX_NUM_PAGES :
1427 			PVSCSI_DEFAULT_NUM_PAGES_PER_RING;
1428 	printk(KERN_INFO
1429 	       "vmw_pvscsi: setting ring_pages to %d\n",
1430 	       pvscsi_ring_pages);
1431 
1432 	pvscsi_template.can_queue =
1433 		min(PVSCSI_MAX_NUM_PAGES_REQ_RING, pvscsi_ring_pages) *
1434 		PVSCSI_MAX_NUM_REQ_ENTRIES_PER_PAGE;
1435 	pvscsi_template.cmd_per_lun =
1436 		min(pvscsi_template.can_queue, pvscsi_cmd_per_lun);
1437 	host = scsi_host_alloc(&pvscsi_template, sizeof(struct pvscsi_adapter));
1438 	if (!host) {
1439 		printk(KERN_ERR "vmw_pvscsi: failed to allocate host\n");
1440 		goto out_release_resources_and_disable;
1441 	}
1442 
1443 	/*
1444 	 * Let's use the real pvscsi_adapter struct here onwards.
1445 	 */
1446 	adapter = shost_priv(host);
1447 	memset(adapter, 0, sizeof(*adapter));
1448 	adapter->dev  = pdev;
1449 	adapter->host = host;
1450 	/*
1451 	 * Copy back what we already have to the allocated adapter struct.
1452 	 */
1453 	adapter->rev = adapter_temp.rev;
1454 	adapter->mmioBase = adapter_temp.mmioBase;
1455 
1456 	spin_lock_init(&adapter->hw_lock);
1457 	host->max_channel = 0;
1458 	host->max_lun     = 1;
1459 	host->max_cmd_len = 16;
1460 	host->max_id      = max_id;
1461 
1462 	pci_set_drvdata(pdev, host);
1463 
1464 	ll_adapter_reset(adapter);
1465 
1466 	adapter->use_msg = pvscsi_setup_msg_workqueue(adapter);
1467 
1468 	error = pvscsi_allocate_rings(adapter);
1469 	if (error) {
1470 		printk(KERN_ERR "vmw_pvscsi: unable to allocate ring memory\n");
1471 		goto out_release_resources;
1472 	}
1473 
1474 	/*
1475 	 * From this point on we should reset the adapter if anything goes
1476 	 * wrong.
1477 	 */
1478 	pvscsi_setup_all_rings(adapter);
1479 
1480 	adapter->cmd_map = kcalloc(adapter->req_depth,
1481 				   sizeof(struct pvscsi_ctx), GFP_KERNEL);
1482 	if (!adapter->cmd_map) {
1483 		printk(KERN_ERR "vmw_pvscsi: failed to allocate memory.\n");
1484 		error = -ENOMEM;
1485 		goto out_reset_adapter;
1486 	}
1487 
1488 	INIT_LIST_HEAD(&adapter->cmd_pool);
1489 	for (i = 0; i < adapter->req_depth; i++) {
1490 		struct pvscsi_ctx *ctx = adapter->cmd_map + i;
1491 		list_add(&ctx->list, &adapter->cmd_pool);
1492 	}
1493 
1494 	error = pvscsi_allocate_sg(adapter);
1495 	if (error) {
1496 		printk(KERN_ERR "vmw_pvscsi: unable to allocate s/g table\n");
1497 		goto out_reset_adapter;
1498 	}
1499 
1500 	if (pvscsi_disable_msix)
1501 		irq_flag &= ~PCI_IRQ_MSIX;
1502 	if (pvscsi_disable_msi)
1503 		irq_flag &= ~PCI_IRQ_MSI;
1504 
1505 	error = pci_alloc_irq_vectors(adapter->dev, 1, 1, irq_flag);
1506 	if (error < 0)
1507 		goto out_reset_adapter;
1508 
1509 	adapter->use_req_threshold = pvscsi_setup_req_threshold(adapter, true);
1510 	printk(KERN_DEBUG "vmw_pvscsi: driver-based request coalescing %sabled\n",
1511 	       adapter->use_req_threshold ? "en" : "dis");
1512 
1513 	if (adapter->dev->msix_enabled || adapter->dev->msi_enabled) {
1514 		printk(KERN_INFO "vmw_pvscsi: using MSI%s\n",
1515 			adapter->dev->msix_enabled ? "-X" : "");
1516 		error = request_irq(pci_irq_vector(pdev, 0), pvscsi_isr,
1517 				0, "vmw_pvscsi", adapter);
1518 	} else {
1519 		printk(KERN_INFO "vmw_pvscsi: using INTx\n");
1520 		error = request_irq(pci_irq_vector(pdev, 0), pvscsi_shared_isr,
1521 				IRQF_SHARED, "vmw_pvscsi", adapter);
1522 	}
1523 
1524 	if (error) {
1525 		printk(KERN_ERR
1526 		       "vmw_pvscsi: unable to request IRQ: %d\n", error);
1527 		goto out_reset_adapter;
1528 	}
1529 
1530 	error = scsi_add_host(host, &pdev->dev);
1531 	if (error) {
1532 		printk(KERN_ERR
1533 		       "vmw_pvscsi: scsi_add_host failed: %d\n", error);
1534 		goto out_reset_adapter;
1535 	}
1536 
1537 	dev_info(&pdev->dev, "VMware PVSCSI rev %d host #%u\n",
1538 		 adapter->rev, host->host_no);
1539 
1540 	pvscsi_unmask_intr(adapter);
1541 
1542 	scsi_scan_host(host);
1543 
1544 	return 0;
1545 
1546 out_reset_adapter:
1547 	ll_adapter_reset(adapter);
1548 out_release_resources:
1549 	pvscsi_shutdown_intr(adapter);
1550 	pvscsi_release_resources(adapter);
1551 	scsi_host_put(host);
1552 out_disable_device:
1553 	pci_disable_device(pdev);
1554 
1555 	return error;
1556 
1557 out_release_resources_and_disable:
1558 	pvscsi_shutdown_intr(adapter);
1559 	pvscsi_release_resources(adapter);
1560 	goto out_disable_device;
1561 }
1562 
1563 static void __pvscsi_shutdown(struct pvscsi_adapter *adapter)
1564 {
1565 	pvscsi_mask_intr(adapter);
1566 
1567 	if (adapter->workqueue)
1568 		flush_workqueue(adapter->workqueue);
1569 
1570 	pvscsi_shutdown_intr(adapter);
1571 
1572 	pvscsi_process_request_ring(adapter);
1573 	pvscsi_process_completion_ring(adapter);
1574 	ll_adapter_reset(adapter);
1575 }
1576 
1577 static void pvscsi_shutdown(struct pci_dev *dev)
1578 {
1579 	struct Scsi_Host *host = pci_get_drvdata(dev);
1580 	struct pvscsi_adapter *adapter = shost_priv(host);
1581 
1582 	__pvscsi_shutdown(adapter);
1583 }
1584 
1585 static void pvscsi_remove(struct pci_dev *pdev)
1586 {
1587 	struct Scsi_Host *host = pci_get_drvdata(pdev);
1588 	struct pvscsi_adapter *adapter = shost_priv(host);
1589 
1590 	scsi_remove_host(host);
1591 
1592 	__pvscsi_shutdown(adapter);
1593 	pvscsi_release_resources(adapter);
1594 
1595 	scsi_host_put(host);
1596 
1597 	pci_disable_device(pdev);
1598 }
1599 
1600 static struct pci_driver pvscsi_pci_driver = {
1601 	.name		= "vmw_pvscsi",
1602 	.id_table	= pvscsi_pci_tbl,
1603 	.probe		= pvscsi_probe,
1604 	.remove		= pvscsi_remove,
1605 	.shutdown       = pvscsi_shutdown,
1606 };
1607 
1608 static int __init pvscsi_init(void)
1609 {
1610 	pr_info("%s - version %s\n",
1611 		PVSCSI_LINUX_DRIVER_DESC, PVSCSI_DRIVER_VERSION_STRING);
1612 	return pci_register_driver(&pvscsi_pci_driver);
1613 }
1614 
1615 static void __exit pvscsi_exit(void)
1616 {
1617 	pci_unregister_driver(&pvscsi_pci_driver);
1618 }
1619 
1620 module_init(pvscsi_init);
1621 module_exit(pvscsi_exit);
1622