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