1 /* -*- linux-c -*-
2  * viodasd.c
3  *  Authors: Dave Boutcher <boutcher@us.ibm.com>
4  *           Ryan Arnold <ryanarn@us.ibm.com>
5  *           Colin Devilbiss <devilbis@us.ibm.com>
6  *           Stephen Rothwell
7  *
8  * (C) Copyright 2000-2004 IBM Corporation
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License as
12  * published by the Free Software Foundation; either version 2 of the
13  * License, or (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23  *
24  * This routine provides access to disk space (termed "DASD" in historical
25  * IBM terms) owned and managed by an OS/400 partition running on the
26  * same box as this Linux partition.
27  *
28  * All disk operations are performed by sending messages back and forth to
29  * the OS/400 partition.
30  */
31 
32 #define pr_fmt(fmt) "viod: " fmt
33 
34 #include <linux/major.h>
35 #include <linux/fs.h>
36 #include <linux/module.h>
37 #include <linux/kernel.h>
38 #include <linux/blkdev.h>
39 #include <linux/genhd.h>
40 #include <linux/hdreg.h>
41 #include <linux/errno.h>
42 #include <linux/init.h>
43 #include <linux/string.h>
44 #include <linux/mutex.h>
45 #include <linux/dma-mapping.h>
46 #include <linux/completion.h>
47 #include <linux/device.h>
48 #include <linux/scatterlist.h>
49 
50 #include <asm/uaccess.h>
51 #include <asm/vio.h>
52 #include <asm/iseries/hv_types.h>
53 #include <asm/iseries/hv_lp_event.h>
54 #include <asm/iseries/hv_lp_config.h>
55 #include <asm/iseries/vio.h>
56 #include <asm/firmware.h>
57 
58 MODULE_DESCRIPTION("iSeries Virtual DASD");
59 MODULE_AUTHOR("Dave Boutcher");
60 MODULE_LICENSE("GPL");
61 
62 /*
63  * We only support 7 partitions per physical disk....so with minor
64  * numbers 0-255 we get a maximum of 32 disks.
65  */
66 #define VIOD_GENHD_NAME		"iseries/vd"
67 
68 #define VIOD_VERS		"1.64"
69 
70 enum {
71 	PARTITION_SHIFT = 3,
72 	MAX_DISKNO = HVMAXARCHITECTEDVIRTUALDISKS,
73 	MAX_DISK_NAME = FIELD_SIZEOF(struct gendisk, disk_name)
74 };
75 
76 static DEFINE_MUTEX(viodasd_mutex);
77 static DEFINE_SPINLOCK(viodasd_spinlock);
78 
79 #define VIOMAXREQ		16
80 
81 #define DEVICE_NO(cell)	((struct viodasd_device *)(cell) - &viodasd_devices[0])
82 
83 struct viodasd_waitevent {
84 	struct completion	com;
85 	int			rc;
86 	u16			sub_result;
87 	int			max_disk;	/* open */
88 };
89 
90 static const struct vio_error_entry viodasd_err_table[] = {
91 	{ 0x0201, EINVAL, "Invalid Range" },
92 	{ 0x0202, EINVAL, "Invalid Token" },
93 	{ 0x0203, EIO, "DMA Error" },
94 	{ 0x0204, EIO, "Use Error" },
95 	{ 0x0205, EIO, "Release Error" },
96 	{ 0x0206, EINVAL, "Invalid Disk" },
97 	{ 0x0207, EBUSY, "Can't Lock" },
98 	{ 0x0208, EIO, "Already Locked" },
99 	{ 0x0209, EIO, "Already Unlocked" },
100 	{ 0x020A, EIO, "Invalid Arg" },
101 	{ 0x020B, EIO, "Bad IFS File" },
102 	{ 0x020C, EROFS, "Read Only Device" },
103 	{ 0x02FF, EIO, "Internal Error" },
104 	{ 0x0000, 0, NULL },
105 };
106 
107 /*
108  * Figure out the biggest I/O request (in sectors) we can accept
109  */
110 #define VIODASD_MAXSECTORS (4096 / 512 * VIOMAXBLOCKDMA)
111 
112 /*
113  * Number of disk I/O requests we've sent to OS/400
114  */
115 static int num_req_outstanding;
116 
117 /*
118  * This is our internal structure for keeping track of disk devices
119  */
120 struct viodasd_device {
121 	u16		cylinders;
122 	u16		tracks;
123 	u16		sectors;
124 	u16		bytes_per_sector;
125 	u64		size;
126 	int		read_only;
127 	spinlock_t	q_lock;
128 	struct gendisk	*disk;
129 	struct device	*dev;
130 } viodasd_devices[MAX_DISKNO];
131 
132 /*
133  * External open entry point.
134  */
viodasd_open(struct block_device * bdev,fmode_t mode)135 static int viodasd_open(struct block_device *bdev, fmode_t mode)
136 {
137 	struct viodasd_device *d = bdev->bd_disk->private_data;
138 	HvLpEvent_Rc hvrc;
139 	struct viodasd_waitevent we;
140 	u16 flags = 0;
141 
142 	if (d->read_only) {
143 		if (mode & FMODE_WRITE)
144 			return -EROFS;
145 		flags = vioblockflags_ro;
146 	}
147 
148 	init_completion(&we.com);
149 
150 	/* Send the open event to OS/400 */
151 	hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
152 			HvLpEvent_Type_VirtualIo,
153 			viomajorsubtype_blockio | vioblockopen,
154 			HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
155 			viopath_sourceinst(viopath_hostLp),
156 			viopath_targetinst(viopath_hostLp),
157 			(u64)(unsigned long)&we, VIOVERSION << 16,
158 			((u64)DEVICE_NO(d) << 48) | ((u64)flags << 32),
159 			0, 0, 0);
160 	if (hvrc != 0) {
161 		pr_warning("HV open failed %d\n", (int)hvrc);
162 		return -EIO;
163 	}
164 
165 	wait_for_completion(&we.com);
166 
167 	/* Check the return code */
168 	if (we.rc != 0) {
169 		const struct vio_error_entry *err =
170 			vio_lookup_rc(viodasd_err_table, we.sub_result);
171 
172 		pr_warning("bad rc opening disk: %d:0x%04x (%s)\n",
173 			   (int)we.rc, we.sub_result, err->msg);
174 		return -EIO;
175 	}
176 
177 	return 0;
178 }
179 
viodasd_unlocked_open(struct block_device * bdev,fmode_t mode)180 static int viodasd_unlocked_open(struct block_device *bdev, fmode_t mode)
181 {
182 	int ret;
183 
184 	mutex_lock(&viodasd_mutex);
185 	ret = viodasd_open(bdev, mode);
186 	mutex_unlock(&viodasd_mutex);
187 
188 	return ret;
189 }
190 
191 
192 /*
193  * External release entry point.
194  */
viodasd_release(struct gendisk * disk,fmode_t mode)195 static int viodasd_release(struct gendisk *disk, fmode_t mode)
196 {
197 	struct viodasd_device *d = disk->private_data;
198 	HvLpEvent_Rc hvrc;
199 
200 	mutex_lock(&viodasd_mutex);
201 	/* Send the event to OS/400.  We DON'T expect a response */
202 	hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
203 			HvLpEvent_Type_VirtualIo,
204 			viomajorsubtype_blockio | vioblockclose,
205 			HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
206 			viopath_sourceinst(viopath_hostLp),
207 			viopath_targetinst(viopath_hostLp),
208 			0, VIOVERSION << 16,
209 			((u64)DEVICE_NO(d) << 48) /* | ((u64)flags << 32) */,
210 			0, 0, 0);
211 	if (hvrc != 0)
212 		pr_warning("HV close call failed %d\n", (int)hvrc);
213 
214 	mutex_unlock(&viodasd_mutex);
215 
216 	return 0;
217 }
218 
219 
220 /* External ioctl entry point.
221  */
viodasd_getgeo(struct block_device * bdev,struct hd_geometry * geo)222 static int viodasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
223 {
224 	struct gendisk *disk = bdev->bd_disk;
225 	struct viodasd_device *d = disk->private_data;
226 
227 	geo->sectors = d->sectors ? d->sectors : 32;
228 	geo->heads = d->tracks ? d->tracks  : 64;
229 	geo->cylinders = d->cylinders ? d->cylinders :
230 		get_capacity(disk) / (geo->sectors * geo->heads);
231 
232 	return 0;
233 }
234 
235 /*
236  * Our file operations table
237  */
238 static const struct block_device_operations viodasd_fops = {
239 	.owner = THIS_MODULE,
240 	.open = viodasd_unlocked_open,
241 	.release = viodasd_release,
242 	.getgeo = viodasd_getgeo,
243 };
244 
245 /*
246  * End a request
247  */
viodasd_end_request(struct request * req,int error,int num_sectors)248 static void viodasd_end_request(struct request *req, int error,
249 		int num_sectors)
250 {
251 	__blk_end_request(req, error, num_sectors << 9);
252 }
253 
254 /*
255  * Send an actual I/O request to OS/400
256  */
send_request(struct request * req)257 static int send_request(struct request *req)
258 {
259 	u64 start;
260 	int direction;
261 	int nsg;
262 	u16 viocmd;
263 	HvLpEvent_Rc hvrc;
264 	struct vioblocklpevent *bevent;
265 	struct HvLpEvent *hev;
266 	struct scatterlist sg[VIOMAXBLOCKDMA];
267 	int sgindex;
268 	struct viodasd_device *d;
269 	unsigned long flags;
270 
271 	start = (u64)blk_rq_pos(req) << 9;
272 
273 	if (rq_data_dir(req) == READ) {
274 		direction = DMA_FROM_DEVICE;
275 		viocmd = viomajorsubtype_blockio | vioblockread;
276 	} else {
277 		direction = DMA_TO_DEVICE;
278 		viocmd = viomajorsubtype_blockio | vioblockwrite;
279 	}
280 
281         d = req->rq_disk->private_data;
282 
283 	/* Now build the scatter-gather list */
284 	sg_init_table(sg, VIOMAXBLOCKDMA);
285 	nsg = blk_rq_map_sg(req->q, req, sg);
286 	nsg = dma_map_sg(d->dev, sg, nsg, direction);
287 
288 	spin_lock_irqsave(&viodasd_spinlock, flags);
289 	num_req_outstanding++;
290 
291 	/* This optimization handles a single DMA block */
292 	if (nsg == 1)
293 		hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
294 				HvLpEvent_Type_VirtualIo, viocmd,
295 				HvLpEvent_AckInd_DoAck,
296 				HvLpEvent_AckType_ImmediateAck,
297 				viopath_sourceinst(viopath_hostLp),
298 				viopath_targetinst(viopath_hostLp),
299 				(u64)(unsigned long)req, VIOVERSION << 16,
300 				((u64)DEVICE_NO(d) << 48), start,
301 				((u64)sg_dma_address(&sg[0])) << 32,
302 				sg_dma_len(&sg[0]));
303 	else {
304 		bevent = (struct vioblocklpevent *)
305 			vio_get_event_buffer(viomajorsubtype_blockio);
306 		if (bevent == NULL) {
307 			pr_warning("error allocating disk event buffer\n");
308 			goto error_ret;
309 		}
310 
311 		/*
312 		 * Now build up the actual request.  Note that we store
313 		 * the pointer to the request in the correlation
314 		 * token so we can match the response up later
315 		 */
316 		memset(bevent, 0, sizeof(struct vioblocklpevent));
317 		hev = &bevent->event;
318 		hev->flags = HV_LP_EVENT_VALID | HV_LP_EVENT_DO_ACK |
319 			HV_LP_EVENT_INT;
320 		hev->xType = HvLpEvent_Type_VirtualIo;
321 		hev->xSubtype = viocmd;
322 		hev->xSourceLp = HvLpConfig_getLpIndex();
323 		hev->xTargetLp = viopath_hostLp;
324 		hev->xSizeMinus1 =
325 			offsetof(struct vioblocklpevent, u.rw_data.dma_info) +
326 			(sizeof(bevent->u.rw_data.dma_info[0]) * nsg) - 1;
327 		hev->xSourceInstanceId = viopath_sourceinst(viopath_hostLp);
328 		hev->xTargetInstanceId = viopath_targetinst(viopath_hostLp);
329 		hev->xCorrelationToken = (u64)req;
330 		bevent->version = VIOVERSION;
331 		bevent->disk = DEVICE_NO(d);
332 		bevent->u.rw_data.offset = start;
333 
334 		/*
335 		 * Copy just the dma information from the sg list
336 		 * into the request
337 		 */
338 		for (sgindex = 0; sgindex < nsg; sgindex++) {
339 			bevent->u.rw_data.dma_info[sgindex].token =
340 				sg_dma_address(&sg[sgindex]);
341 			bevent->u.rw_data.dma_info[sgindex].len =
342 				sg_dma_len(&sg[sgindex]);
343 		}
344 
345 		/* Send the request */
346 		hvrc = HvCallEvent_signalLpEvent(&bevent->event);
347 		vio_free_event_buffer(viomajorsubtype_blockio, bevent);
348 	}
349 
350 	if (hvrc != HvLpEvent_Rc_Good) {
351 		pr_warning("error sending disk event to OS/400 (rc %d)\n",
352 			   (int)hvrc);
353 		goto error_ret;
354 	}
355 	spin_unlock_irqrestore(&viodasd_spinlock, flags);
356 	return 0;
357 
358 error_ret:
359 	num_req_outstanding--;
360 	spin_unlock_irqrestore(&viodasd_spinlock, flags);
361 	dma_unmap_sg(d->dev, sg, nsg, direction);
362 	return -1;
363 }
364 
365 /*
366  * This is the external request processing routine
367  */
do_viodasd_request(struct request_queue * q)368 static void do_viodasd_request(struct request_queue *q)
369 {
370 	struct request *req;
371 
372 	/*
373 	 * If we already have the maximum number of requests
374 	 * outstanding to OS/400 just bail out. We'll come
375 	 * back later.
376 	 */
377 	while (num_req_outstanding < VIOMAXREQ) {
378 		req = blk_fetch_request(q);
379 		if (req == NULL)
380 			return;
381 		/* check that request contains a valid command */
382 		if (req->cmd_type != REQ_TYPE_FS) {
383 			viodasd_end_request(req, -EIO, blk_rq_sectors(req));
384 			continue;
385 		}
386 		/* Try sending the request */
387 		if (send_request(req) != 0)
388 			viodasd_end_request(req, -EIO, blk_rq_sectors(req));
389 	}
390 }
391 
392 /*
393  * Probe a single disk and fill in the viodasd_device structure
394  * for it.
395  */
probe_disk(struct viodasd_device * d)396 static int probe_disk(struct viodasd_device *d)
397 {
398 	HvLpEvent_Rc hvrc;
399 	struct viodasd_waitevent we;
400 	int dev_no = DEVICE_NO(d);
401 	struct gendisk *g;
402 	struct request_queue *q;
403 	u16 flags = 0;
404 
405 retry:
406 	init_completion(&we.com);
407 
408 	/* Send the open event to OS/400 */
409 	hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
410 			HvLpEvent_Type_VirtualIo,
411 			viomajorsubtype_blockio | vioblockopen,
412 			HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
413 			viopath_sourceinst(viopath_hostLp),
414 			viopath_targetinst(viopath_hostLp),
415 			(u64)(unsigned long)&we, VIOVERSION << 16,
416 			((u64)dev_no << 48) | ((u64)flags<< 32),
417 			0, 0, 0);
418 	if (hvrc != 0) {
419 		pr_warning("bad rc on HV open %d\n", (int)hvrc);
420 		return 0;
421 	}
422 
423 	wait_for_completion(&we.com);
424 
425 	if (we.rc != 0) {
426 		if (flags != 0)
427 			return 0;
428 		/* try again with read only flag set */
429 		flags = vioblockflags_ro;
430 		goto retry;
431 	}
432 	if (we.max_disk > (MAX_DISKNO - 1)) {
433 		printk_once(KERN_INFO pr_fmt("Only examining the first %d of %d disks connected\n"),
434 			    MAX_DISKNO, we.max_disk + 1);
435 	}
436 
437 	/* Send the close event to OS/400.  We DON'T expect a response */
438 	hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
439 			HvLpEvent_Type_VirtualIo,
440 			viomajorsubtype_blockio | vioblockclose,
441 			HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
442 			viopath_sourceinst(viopath_hostLp),
443 			viopath_targetinst(viopath_hostLp),
444 			0, VIOVERSION << 16,
445 			((u64)dev_no << 48) | ((u64)flags << 32),
446 			0, 0, 0);
447 	if (hvrc != 0) {
448 		pr_warning("bad rc sending event to OS/400 %d\n", (int)hvrc);
449 		return 0;
450 	}
451 
452 	if (d->dev == NULL) {
453 		/* this is when we reprobe for new disks */
454 		if (vio_create_viodasd(dev_no) == NULL) {
455 			pr_warning("cannot allocate virtual device for disk %d\n",
456 				   dev_no);
457 			return 0;
458 		}
459 		/*
460 		 * The vio_create_viodasd will have recursed into this
461 		 * routine with d->dev set to the new vio device and
462 		 * will finish the setup of the disk below.
463 		 */
464 		return 1;
465 	}
466 
467 	/* create the request queue for the disk */
468 	spin_lock_init(&d->q_lock);
469 	q = blk_init_queue(do_viodasd_request, &d->q_lock);
470 	if (q == NULL) {
471 		pr_warning("cannot allocate queue for disk %d\n", dev_no);
472 		return 0;
473 	}
474 	g = alloc_disk(1 << PARTITION_SHIFT);
475 	if (g == NULL) {
476 		pr_warning("cannot allocate disk structure for disk %d\n",
477 			   dev_no);
478 		blk_cleanup_queue(q);
479 		return 0;
480 	}
481 
482 	d->disk = g;
483 	blk_queue_max_segments(q, VIOMAXBLOCKDMA);
484 	blk_queue_max_hw_sectors(q, VIODASD_MAXSECTORS);
485 	g->major = VIODASD_MAJOR;
486 	g->first_minor = dev_no << PARTITION_SHIFT;
487 	if (dev_no >= 26)
488 		snprintf(g->disk_name, sizeof(g->disk_name),
489 				VIOD_GENHD_NAME "%c%c",
490 				'a' + (dev_no / 26) - 1, 'a' + (dev_no % 26));
491 	else
492 		snprintf(g->disk_name, sizeof(g->disk_name),
493 				VIOD_GENHD_NAME "%c", 'a' + (dev_no % 26));
494 	g->fops = &viodasd_fops;
495 	g->queue = q;
496 	g->private_data = d;
497 	g->driverfs_dev = d->dev;
498 	set_capacity(g, d->size >> 9);
499 
500 	pr_info("disk %d: %lu sectors (%lu MB) CHS=%d/%d/%d sector size %d%s\n",
501 		dev_no, (unsigned long)(d->size >> 9),
502 		(unsigned long)(d->size >> 20),
503 		(int)d->cylinders, (int)d->tracks,
504 		(int)d->sectors, (int)d->bytes_per_sector,
505 		d->read_only ? " (RO)" : "");
506 
507 	/* register us in the global list */
508 	add_disk(g);
509 	return 1;
510 }
511 
512 /* returns the total number of scatterlist elements converted */
block_event_to_scatterlist(const struct vioblocklpevent * bevent,struct scatterlist * sg,int * total_len)513 static int block_event_to_scatterlist(const struct vioblocklpevent *bevent,
514 		struct scatterlist *sg, int *total_len)
515 {
516 	int i, numsg;
517 	const struct rw_data *rw_data = &bevent->u.rw_data;
518 	static const int offset =
519 		offsetof(struct vioblocklpevent, u.rw_data.dma_info);
520 	static const int element_size = sizeof(rw_data->dma_info[0]);
521 
522 	numsg = ((bevent->event.xSizeMinus1 + 1) - offset) / element_size;
523 	if (numsg > VIOMAXBLOCKDMA)
524 		numsg = VIOMAXBLOCKDMA;
525 
526 	*total_len = 0;
527 	sg_init_table(sg, VIOMAXBLOCKDMA);
528 	for (i = 0; (i < numsg) && (rw_data->dma_info[i].len > 0); ++i) {
529 		sg_dma_address(&sg[i]) = rw_data->dma_info[i].token;
530 		sg_dma_len(&sg[i]) = rw_data->dma_info[i].len;
531 		*total_len += rw_data->dma_info[i].len;
532 	}
533 	return i;
534 }
535 
536 /*
537  * Restart all queues, starting with the one _after_ the disk given,
538  * thus reducing the chance of starvation of higher numbered disks.
539  */
viodasd_restart_all_queues_starting_from(int first_index)540 static void viodasd_restart_all_queues_starting_from(int first_index)
541 {
542 	int i;
543 
544 	for (i = first_index + 1; i < MAX_DISKNO; ++i)
545 		if (viodasd_devices[i].disk)
546 			blk_run_queue(viodasd_devices[i].disk->queue);
547 	for (i = 0; i <= first_index; ++i)
548 		if (viodasd_devices[i].disk)
549 			blk_run_queue(viodasd_devices[i].disk->queue);
550 }
551 
552 /*
553  * For read and write requests, decrement the number of outstanding requests,
554  * Free the DMA buffers we allocated.
555  */
viodasd_handle_read_write(struct vioblocklpevent * bevent)556 static int viodasd_handle_read_write(struct vioblocklpevent *bevent)
557 {
558 	int num_sg, num_sect, pci_direction, total_len;
559 	struct request *req;
560 	struct scatterlist sg[VIOMAXBLOCKDMA];
561 	struct HvLpEvent *event = &bevent->event;
562 	unsigned long irq_flags;
563 	struct viodasd_device *d;
564 	int error;
565 	spinlock_t *qlock;
566 
567 	num_sg = block_event_to_scatterlist(bevent, sg, &total_len);
568 	num_sect = total_len >> 9;
569 	if (event->xSubtype == (viomajorsubtype_blockio | vioblockread))
570 		pci_direction = DMA_FROM_DEVICE;
571 	else
572 		pci_direction = DMA_TO_DEVICE;
573 	req = (struct request *)bevent->event.xCorrelationToken;
574 	d = req->rq_disk->private_data;
575 
576 	dma_unmap_sg(d->dev, sg, num_sg, pci_direction);
577 
578 	/*
579 	 * Since this is running in interrupt mode, we need to make sure
580 	 * we're not stepping on any global I/O operations
581 	 */
582 	spin_lock_irqsave(&viodasd_spinlock, irq_flags);
583 	num_req_outstanding--;
584 	spin_unlock_irqrestore(&viodasd_spinlock, irq_flags);
585 
586 	error = (event->xRc == HvLpEvent_Rc_Good) ? 0 : -EIO;
587 	if (error) {
588 		const struct vio_error_entry *err;
589 		err = vio_lookup_rc(viodasd_err_table, bevent->sub_result);
590 		pr_warning("read/write error %d:0x%04x (%s)\n",
591 			   event->xRc, bevent->sub_result, err->msg);
592 		num_sect = blk_rq_sectors(req);
593 	}
594 	qlock = req->q->queue_lock;
595 	spin_lock_irqsave(qlock, irq_flags);
596 	viodasd_end_request(req, error, num_sect);
597 	spin_unlock_irqrestore(qlock, irq_flags);
598 
599 	/* Finally, try to get more requests off of this device's queue */
600 	viodasd_restart_all_queues_starting_from(DEVICE_NO(d));
601 
602 	return 0;
603 }
604 
605 /* This routine handles incoming block LP events */
handle_block_event(struct HvLpEvent * event)606 static void handle_block_event(struct HvLpEvent *event)
607 {
608 	struct vioblocklpevent *bevent = (struct vioblocklpevent *)event;
609 	struct viodasd_waitevent *pwe;
610 
611 	if (event == NULL)
612 		/* Notification that a partition went away! */
613 		return;
614 	/* First, we should NEVER get an int here...only acks */
615 	if (hvlpevent_is_int(event)) {
616 		pr_warning("Yikes! got an int in viodasd event handler!\n");
617 		if (hvlpevent_need_ack(event)) {
618 			event->xRc = HvLpEvent_Rc_InvalidSubtype;
619 			HvCallEvent_ackLpEvent(event);
620 		}
621 	}
622 
623 	switch (event->xSubtype & VIOMINOR_SUBTYPE_MASK) {
624 	case vioblockopen:
625 		/*
626 		 * Handle a response to an open request.  We get all the
627 		 * disk information in the response, so update it.  The
628 		 * correlation token contains a pointer to a waitevent
629 		 * structure that has a completion in it.  update the
630 		 * return code in the waitevent structure and post the
631 		 * completion to wake up the guy who sent the request
632 		 */
633 		pwe = (struct viodasd_waitevent *)event->xCorrelationToken;
634 		pwe->rc = event->xRc;
635 		pwe->sub_result = bevent->sub_result;
636 		if (event->xRc == HvLpEvent_Rc_Good) {
637 			const struct open_data *data = &bevent->u.open_data;
638 			struct viodasd_device *device =
639 				&viodasd_devices[bevent->disk];
640 			device->read_only =
641 				bevent->flags & vioblockflags_ro;
642 			device->size = data->disk_size;
643 			device->cylinders = data->cylinders;
644 			device->tracks = data->tracks;
645 			device->sectors = data->sectors;
646 			device->bytes_per_sector = data->bytes_per_sector;
647 			pwe->max_disk = data->max_disk;
648 		}
649 		complete(&pwe->com);
650 		break;
651 	case vioblockclose:
652 		break;
653 	case vioblockread:
654 	case vioblockwrite:
655 		viodasd_handle_read_write(bevent);
656 		break;
657 
658 	default:
659 		pr_warning("invalid subtype!");
660 		if (hvlpevent_need_ack(event)) {
661 			event->xRc = HvLpEvent_Rc_InvalidSubtype;
662 			HvCallEvent_ackLpEvent(event);
663 		}
664 	}
665 }
666 
667 /*
668  * Get the driver to reprobe for more disks.
669  */
probe_disks(struct device_driver * drv,const char * buf,size_t count)670 static ssize_t probe_disks(struct device_driver *drv, const char *buf,
671 		size_t count)
672 {
673 	struct viodasd_device *d;
674 
675 	for (d = viodasd_devices; d < &viodasd_devices[MAX_DISKNO]; d++) {
676 		if (d->disk == NULL)
677 			probe_disk(d);
678 	}
679 	return count;
680 }
681 static DRIVER_ATTR(probe, S_IWUSR, NULL, probe_disks);
682 
viodasd_probe(struct vio_dev * vdev,const struct vio_device_id * id)683 static int viodasd_probe(struct vio_dev *vdev, const struct vio_device_id *id)
684 {
685 	struct viodasd_device *d = &viodasd_devices[vdev->unit_address];
686 
687 	d->dev = &vdev->dev;
688 	if (!probe_disk(d))
689 		return -ENODEV;
690 	return 0;
691 }
692 
viodasd_remove(struct vio_dev * vdev)693 static int viodasd_remove(struct vio_dev *vdev)
694 {
695 	struct viodasd_device *d;
696 
697 	d = &viodasd_devices[vdev->unit_address];
698 	if (d->disk) {
699 		del_gendisk(d->disk);
700 		blk_cleanup_queue(d->disk->queue);
701 		put_disk(d->disk);
702 		d->disk = NULL;
703 	}
704 	d->dev = NULL;
705 	return 0;
706 }
707 
708 /**
709  * viodasd_device_table: Used by vio.c to match devices that we
710  * support.
711  */
712 static struct vio_device_id viodasd_device_table[] __devinitdata = {
713 	{ "block", "IBM,iSeries-viodasd" },
714 	{ "", "" }
715 };
716 MODULE_DEVICE_TABLE(vio, viodasd_device_table);
717 
718 static struct vio_driver viodasd_driver = {
719 	.id_table = viodasd_device_table,
720 	.probe = viodasd_probe,
721 	.remove = viodasd_remove,
722 	.driver = {
723 		.name = "viodasd",
724 		.owner = THIS_MODULE,
725 	}
726 };
727 
728 static int need_delete_probe;
729 
730 /*
731  * Initialize the whole device driver.  Handle module and non-module
732  * versions
733  */
viodasd_init(void)734 static int __init viodasd_init(void)
735 {
736 	int rc;
737 
738 	if (!firmware_has_feature(FW_FEATURE_ISERIES)) {
739 		rc = -ENODEV;
740 		goto early_fail;
741 	}
742 
743 	/* Try to open to our host lp */
744 	if (viopath_hostLp == HvLpIndexInvalid)
745 		vio_set_hostlp();
746 
747 	if (viopath_hostLp == HvLpIndexInvalid) {
748 		pr_warning("invalid hosting partition\n");
749 		rc = -EIO;
750 		goto early_fail;
751 	}
752 
753 	pr_info("vers " VIOD_VERS ", hosting partition %d\n", viopath_hostLp);
754 
755         /* register the block device */
756 	rc =  register_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
757 	if (rc) {
758 		pr_warning("Unable to get major number %d for %s\n",
759 			   VIODASD_MAJOR, VIOD_GENHD_NAME);
760 		goto early_fail;
761 	}
762 	/* Actually open the path to the hosting partition */
763 	rc = viopath_open(viopath_hostLp, viomajorsubtype_blockio,
764 				VIOMAXREQ + 2);
765 	if (rc) {
766 		pr_warning("error opening path to host partition %d\n",
767 			   viopath_hostLp);
768 		goto unregister_blk;
769 	}
770 
771 	/* Initialize our request handler */
772 	vio_setHandler(viomajorsubtype_blockio, handle_block_event);
773 
774 	rc = vio_register_driver(&viodasd_driver);
775 	if (rc) {
776 		pr_warning("vio_register_driver failed\n");
777 		goto unset_handler;
778 	}
779 
780 	/*
781 	 * If this call fails, it just means that we cannot dynamically
782 	 * add virtual disks, but the driver will still work fine for
783 	 * all existing disk, so ignore the failure.
784 	 */
785 	if (!driver_create_file(&viodasd_driver.driver, &driver_attr_probe))
786 		need_delete_probe = 1;
787 
788 	return 0;
789 
790 unset_handler:
791 	vio_clearHandler(viomajorsubtype_blockio);
792 	viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
793 unregister_blk:
794 	unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
795 early_fail:
796 	return rc;
797 }
798 module_init(viodasd_init);
799 
viodasd_exit(void)800 void __exit viodasd_exit(void)
801 {
802 	if (need_delete_probe)
803 		driver_remove_file(&viodasd_driver.driver, &driver_attr_probe);
804 	vio_unregister_driver(&viodasd_driver);
805 	vio_clearHandler(viomajorsubtype_blockio);
806 	viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
807 	unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
808 }
809 module_exit(viodasd_exit);
810