xref: /openbmc/linux/drivers/s390/virtio/virtio_ccw.c (revision 7f33105cdd59a99d068d3d147723a865d10e2260)
1  // SPDX-License-Identifier: GPL-2.0
2  /*
3   * ccw based virtio transport
4   *
5   * Copyright IBM Corp. 2012, 2014
6   *
7   *    Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
8   */
9  
10  #include <linux/kernel_stat.h>
11  #include <linux/init.h>
12  #include <linux/memblock.h>
13  #include <linux/err.h>
14  #include <linux/virtio.h>
15  #include <linux/virtio_config.h>
16  #include <linux/slab.h>
17  #include <linux/interrupt.h>
18  #include <linux/virtio_ring.h>
19  #include <linux/pfn.h>
20  #include <linux/async.h>
21  #include <linux/wait.h>
22  #include <linux/list.h>
23  #include <linux/bitops.h>
24  #include <linux/moduleparam.h>
25  #include <linux/io.h>
26  #include <linux/kvm_para.h>
27  #include <linux/notifier.h>
28  #include <asm/diag.h>
29  #include <asm/setup.h>
30  #include <asm/irq.h>
31  #include <asm/cio.h>
32  #include <asm/ccwdev.h>
33  #include <asm/virtio-ccw.h>
34  #include <asm/isc.h>
35  #include <asm/airq.h>
36  #include <asm/tpi.h>
37  
38  /*
39   * virtio related functions
40   */
41  
42  struct vq_config_block {
43  	__u16 index;
44  	__u16 num;
45  } __packed;
46  
47  #define VIRTIO_CCW_CONFIG_SIZE 0x100
48  /* same as PCI config space size, should be enough for all drivers */
49  
50  struct vcdev_dma_area {
51  	unsigned long indicators;
52  	unsigned long indicators2;
53  	struct vq_config_block config_block;
54  	__u8 status;
55  };
56  
57  struct virtio_ccw_device {
58  	struct virtio_device vdev;
59  	__u8 config[VIRTIO_CCW_CONFIG_SIZE];
60  	struct ccw_device *cdev;
61  	__u32 curr_io;
62  	int err;
63  	unsigned int revision; /* Transport revision */
64  	wait_queue_head_t wait_q;
65  	spinlock_t lock;
66  	rwlock_t irq_lock;
67  	struct mutex io_lock; /* Serializes I/O requests */
68  	struct list_head virtqueues;
69  	bool is_thinint;
70  	bool going_away;
71  	bool device_lost;
72  	unsigned int config_ready;
73  	void *airq_info;
74  	struct vcdev_dma_area *dma_area;
75  };
76  
77  static inline unsigned long *indicators(struct virtio_ccw_device *vcdev)
78  {
79  	return &vcdev->dma_area->indicators;
80  }
81  
82  static inline unsigned long *indicators2(struct virtio_ccw_device *vcdev)
83  {
84  	return &vcdev->dma_area->indicators2;
85  }
86  
87  struct vq_info_block_legacy {
88  	__u64 queue;
89  	__u32 align;
90  	__u16 index;
91  	__u16 num;
92  } __packed;
93  
94  struct vq_info_block {
95  	__u64 desc;
96  	__u32 res0;
97  	__u16 index;
98  	__u16 num;
99  	__u64 avail;
100  	__u64 used;
101  } __packed;
102  
103  struct virtio_feature_desc {
104  	__le32 features;
105  	__u8 index;
106  } __packed;
107  
108  struct virtio_thinint_area {
109  	unsigned long summary_indicator;
110  	unsigned long indicator;
111  	u64 bit_nr;
112  	u8 isc;
113  } __packed;
114  
115  struct virtio_rev_info {
116  	__u16 revision;
117  	__u16 length;
118  	__u8 data[];
119  };
120  
121  /* the highest virtio-ccw revision we support */
122  #define VIRTIO_CCW_REV_MAX 2
123  
124  struct virtio_ccw_vq_info {
125  	struct virtqueue *vq;
126  	int num;
127  	union {
128  		struct vq_info_block s;
129  		struct vq_info_block_legacy l;
130  	} *info_block;
131  	int bit_nr;
132  	struct list_head node;
133  	long cookie;
134  };
135  
136  #define VIRTIO_AIRQ_ISC IO_SCH_ISC /* inherit from subchannel */
137  
138  #define VIRTIO_IV_BITS (L1_CACHE_BYTES * 8)
139  #define MAX_AIRQ_AREAS 20
140  
141  static int virtio_ccw_use_airq = 1;
142  
143  struct airq_info {
144  	rwlock_t lock;
145  	u8 summary_indicator_idx;
146  	struct airq_struct airq;
147  	struct airq_iv *aiv;
148  };
149  static struct airq_info *airq_areas[MAX_AIRQ_AREAS];
150  static DEFINE_MUTEX(airq_areas_lock);
151  
152  static u8 *summary_indicators;
153  
154  static inline u8 *get_summary_indicator(struct airq_info *info)
155  {
156  	return summary_indicators + info->summary_indicator_idx;
157  }
158  
159  #define CCW_CMD_SET_VQ 0x13
160  #define CCW_CMD_VDEV_RESET 0x33
161  #define CCW_CMD_SET_IND 0x43
162  #define CCW_CMD_SET_CONF_IND 0x53
163  #define CCW_CMD_READ_FEAT 0x12
164  #define CCW_CMD_WRITE_FEAT 0x11
165  #define CCW_CMD_READ_CONF 0x22
166  #define CCW_CMD_WRITE_CONF 0x21
167  #define CCW_CMD_WRITE_STATUS 0x31
168  #define CCW_CMD_READ_VQ_CONF 0x32
169  #define CCW_CMD_READ_STATUS 0x72
170  #define CCW_CMD_SET_IND_ADAPTER 0x73
171  #define CCW_CMD_SET_VIRTIO_REV 0x83
172  
173  #define VIRTIO_CCW_DOING_SET_VQ 0x00010000
174  #define VIRTIO_CCW_DOING_RESET 0x00040000
175  #define VIRTIO_CCW_DOING_READ_FEAT 0x00080000
176  #define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000
177  #define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000
178  #define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000
179  #define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000
180  #define VIRTIO_CCW_DOING_SET_IND 0x01000000
181  #define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000
182  #define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000
183  #define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
184  #define VIRTIO_CCW_DOING_SET_VIRTIO_REV 0x10000000
185  #define VIRTIO_CCW_DOING_READ_STATUS 0x20000000
186  #define VIRTIO_CCW_INTPARM_MASK 0xffff0000
187  
188  static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
189  {
190  	return container_of(vdev, struct virtio_ccw_device, vdev);
191  }
192  
193  static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
194  {
195  	unsigned long i, flags;
196  
197  	write_lock_irqsave(&info->lock, flags);
198  	for (i = 0; i < airq_iv_end(info->aiv); i++) {
199  		if (vq == (void *)airq_iv_get_ptr(info->aiv, i)) {
200  			airq_iv_free_bit(info->aiv, i);
201  			airq_iv_set_ptr(info->aiv, i, 0);
202  			break;
203  		}
204  	}
205  	write_unlock_irqrestore(&info->lock, flags);
206  }
207  
208  static void virtio_airq_handler(struct airq_struct *airq,
209  				struct tpi_info *tpi_info)
210  {
211  	struct airq_info *info = container_of(airq, struct airq_info, airq);
212  	unsigned long ai;
213  
214  	inc_irq_stat(IRQIO_VAI);
215  	read_lock(&info->lock);
216  	/* Walk through indicators field, summary indicator active. */
217  	for (ai = 0;;) {
218  		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
219  		if (ai == -1UL)
220  			break;
221  		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
222  	}
223  	*(get_summary_indicator(info)) = 0;
224  	smp_wmb();
225  	/* Walk through indicators field, summary indicator not active. */
226  	for (ai = 0;;) {
227  		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
228  		if (ai == -1UL)
229  			break;
230  		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
231  	}
232  	read_unlock(&info->lock);
233  }
234  
235  static struct airq_info *new_airq_info(int index)
236  {
237  	struct airq_info *info;
238  	int rc;
239  
240  	info = kzalloc(sizeof(*info), GFP_KERNEL);
241  	if (!info)
242  		return NULL;
243  	rwlock_init(&info->lock);
244  	info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR
245  				   | AIRQ_IV_CACHELINE, NULL);
246  	if (!info->aiv) {
247  		kfree(info);
248  		return NULL;
249  	}
250  	info->airq.handler = virtio_airq_handler;
251  	info->summary_indicator_idx = index;
252  	info->airq.lsi_ptr = get_summary_indicator(info);
253  	info->airq.lsi_mask = 0xff;
254  	info->airq.isc = VIRTIO_AIRQ_ISC;
255  	rc = register_adapter_interrupt(&info->airq);
256  	if (rc) {
257  		airq_iv_release(info->aiv);
258  		kfree(info);
259  		return NULL;
260  	}
261  	return info;
262  }
263  
264  static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs,
265  					u64 *first, void **airq_info)
266  {
267  	int i, j;
268  	struct airq_info *info;
269  	unsigned long indicator_addr = 0;
270  	unsigned long bit, flags;
271  
272  	for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
273  		mutex_lock(&airq_areas_lock);
274  		if (!airq_areas[i])
275  			airq_areas[i] = new_airq_info(i);
276  		info = airq_areas[i];
277  		mutex_unlock(&airq_areas_lock);
278  		if (!info)
279  			return 0;
280  		write_lock_irqsave(&info->lock, flags);
281  		bit = airq_iv_alloc(info->aiv, nvqs);
282  		if (bit == -1UL) {
283  			/* Not enough vacancies. */
284  			write_unlock_irqrestore(&info->lock, flags);
285  			continue;
286  		}
287  		*first = bit;
288  		*airq_info = info;
289  		indicator_addr = (unsigned long)info->aiv->vector;
290  		for (j = 0; j < nvqs; j++) {
291  			airq_iv_set_ptr(info->aiv, bit + j,
292  					(unsigned long)vqs[j]);
293  		}
294  		write_unlock_irqrestore(&info->lock, flags);
295  	}
296  	return indicator_addr;
297  }
298  
299  static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
300  {
301  	struct virtio_ccw_vq_info *info;
302  
303  	if (!vcdev->airq_info)
304  		return;
305  	list_for_each_entry(info, &vcdev->virtqueues, node)
306  		drop_airq_indicator(info->vq, vcdev->airq_info);
307  }
308  
309  static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)
310  {
311  	unsigned long flags;
312  	__u32 ret;
313  
314  	spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
315  	if (vcdev->err)
316  		ret = 0;
317  	else
318  		ret = vcdev->curr_io & flag;
319  	spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
320  	return ret;
321  }
322  
323  static int ccw_io_helper(struct virtio_ccw_device *vcdev,
324  			 struct ccw1 *ccw, __u32 intparm)
325  {
326  	int ret;
327  	unsigned long flags;
328  	int flag = intparm & VIRTIO_CCW_INTPARM_MASK;
329  
330  	mutex_lock(&vcdev->io_lock);
331  	do {
332  		spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
333  		ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
334  		if (!ret) {
335  			if (!vcdev->curr_io)
336  				vcdev->err = 0;
337  			vcdev->curr_io |= flag;
338  		}
339  		spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
340  		cpu_relax();
341  	} while (ret == -EBUSY);
342  	wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
343  	ret = ret ? ret : vcdev->err;
344  	mutex_unlock(&vcdev->io_lock);
345  	return ret;
346  }
347  
348  static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
349  				      struct ccw1 *ccw)
350  {
351  	int ret;
352  	unsigned long *indicatorp = NULL;
353  	struct virtio_thinint_area *thinint_area = NULL;
354  	struct airq_info *airq_info = vcdev->airq_info;
355  
356  	if (vcdev->is_thinint) {
357  		thinint_area = ccw_device_dma_zalloc(vcdev->cdev,
358  						     sizeof(*thinint_area));
359  		if (!thinint_area)
360  			return;
361  		thinint_area->summary_indicator =
362  			(unsigned long) get_summary_indicator(airq_info);
363  		thinint_area->isc = VIRTIO_AIRQ_ISC;
364  		ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
365  		ccw->count = sizeof(*thinint_area);
366  		ccw->cda = (__u32)virt_to_phys(thinint_area);
367  	} else {
368  		/* payload is the address of the indicators */
369  		indicatorp = ccw_device_dma_zalloc(vcdev->cdev,
370  						   sizeof(indicators(vcdev)));
371  		if (!indicatorp)
372  			return;
373  		*indicatorp = 0;
374  		ccw->cmd_code = CCW_CMD_SET_IND;
375  		ccw->count = sizeof(indicators(vcdev));
376  		ccw->cda = (__u32)virt_to_phys(indicatorp);
377  	}
378  	/* Deregister indicators from host. */
379  	*indicators(vcdev) = 0;
380  	ccw->flags = 0;
381  	ret = ccw_io_helper(vcdev, ccw,
382  			    vcdev->is_thinint ?
383  			    VIRTIO_CCW_DOING_SET_IND_ADAPTER :
384  			    VIRTIO_CCW_DOING_SET_IND);
385  	if (ret && (ret != -ENODEV))
386  		dev_info(&vcdev->cdev->dev,
387  			 "Failed to deregister indicators (%d)\n", ret);
388  	else if (vcdev->is_thinint)
389  		virtio_ccw_drop_indicators(vcdev);
390  	ccw_device_dma_free(vcdev->cdev, indicatorp, sizeof(indicators(vcdev)));
391  	ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area));
392  }
393  
394  static inline bool virtio_ccw_do_kvm_notify(struct virtqueue *vq, u32 data)
395  {
396  	struct virtio_ccw_vq_info *info = vq->priv;
397  	struct virtio_ccw_device *vcdev;
398  	struct subchannel_id schid;
399  
400  	vcdev = to_vc_device(info->vq->vdev);
401  	ccw_device_get_schid(vcdev->cdev, &schid);
402  	BUILD_BUG_ON(sizeof(struct subchannel_id) != sizeof(unsigned int));
403  	info->cookie = kvm_hypercall3(KVM_S390_VIRTIO_CCW_NOTIFY,
404  				      *((unsigned int *)&schid),
405  				      data, info->cookie);
406  	if (info->cookie < 0)
407  		return false;
408  	return true;
409  }
410  
411  static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
412  {
413  	return virtio_ccw_do_kvm_notify(vq, vq->index);
414  }
415  
416  static bool virtio_ccw_kvm_notify_with_data(struct virtqueue *vq)
417  {
418  	return virtio_ccw_do_kvm_notify(vq, vring_notification_data(vq));
419  }
420  
421  static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
422  				   struct ccw1 *ccw, int index)
423  {
424  	int ret;
425  
426  	vcdev->dma_area->config_block.index = index;
427  	ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
428  	ccw->flags = 0;
429  	ccw->count = sizeof(struct vq_config_block);
430  	ccw->cda = (__u32)virt_to_phys(&vcdev->dma_area->config_block);
431  	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
432  	if (ret)
433  		return ret;
434  	return vcdev->dma_area->config_block.num ?: -ENOENT;
435  }
436  
437  static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
438  {
439  	struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
440  	struct virtio_ccw_vq_info *info = vq->priv;
441  	unsigned long flags;
442  	int ret;
443  	unsigned int index = vq->index;
444  
445  	/* Remove from our list. */
446  	spin_lock_irqsave(&vcdev->lock, flags);
447  	list_del(&info->node);
448  	spin_unlock_irqrestore(&vcdev->lock, flags);
449  
450  	/* Release from host. */
451  	if (vcdev->revision == 0) {
452  		info->info_block->l.queue = 0;
453  		info->info_block->l.align = 0;
454  		info->info_block->l.index = index;
455  		info->info_block->l.num = 0;
456  		ccw->count = sizeof(info->info_block->l);
457  	} else {
458  		info->info_block->s.desc = 0;
459  		info->info_block->s.index = index;
460  		info->info_block->s.num = 0;
461  		info->info_block->s.avail = 0;
462  		info->info_block->s.used = 0;
463  		ccw->count = sizeof(info->info_block->s);
464  	}
465  	ccw->cmd_code = CCW_CMD_SET_VQ;
466  	ccw->flags = 0;
467  	ccw->cda = (__u32)virt_to_phys(info->info_block);
468  	ret = ccw_io_helper(vcdev, ccw,
469  			    VIRTIO_CCW_DOING_SET_VQ | index);
470  	/*
471  	 * -ENODEV isn't considered an error: The device is gone anyway.
472  	 * This may happen on device detach.
473  	 */
474  	if (ret && (ret != -ENODEV))
475  		dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d\n",
476  			 ret, index);
477  
478  	vring_del_virtqueue(vq);
479  	ccw_device_dma_free(vcdev->cdev, info->info_block,
480  			    sizeof(*info->info_block));
481  	kfree(info);
482  }
483  
484  static void virtio_ccw_del_vqs(struct virtio_device *vdev)
485  {
486  	struct virtqueue *vq, *n;
487  	struct ccw1 *ccw;
488  	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
489  
490  	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
491  	if (!ccw)
492  		return;
493  
494  	virtio_ccw_drop_indicator(vcdev, ccw);
495  
496  	list_for_each_entry_safe(vq, n, &vdev->vqs, list)
497  		virtio_ccw_del_vq(vq, ccw);
498  
499  	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
500  }
501  
502  static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
503  					     int i, vq_callback_t *callback,
504  					     const char *name, bool ctx,
505  					     struct ccw1 *ccw)
506  {
507  	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
508  	bool (*notify)(struct virtqueue *vq);
509  	int err;
510  	struct virtqueue *vq = NULL;
511  	struct virtio_ccw_vq_info *info;
512  	u64 queue;
513  	unsigned long flags;
514  	bool may_reduce;
515  
516  	if (__virtio_test_bit(vdev, VIRTIO_F_NOTIFICATION_DATA))
517  		notify = virtio_ccw_kvm_notify_with_data;
518  	else
519  		notify = virtio_ccw_kvm_notify;
520  
521  	/* Allocate queue. */
522  	info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
523  	if (!info) {
524  		dev_warn(&vcdev->cdev->dev, "no info\n");
525  		err = -ENOMEM;
526  		goto out_err;
527  	}
528  	info->info_block = ccw_device_dma_zalloc(vcdev->cdev,
529  						 sizeof(*info->info_block));
530  	if (!info->info_block) {
531  		dev_warn(&vcdev->cdev->dev, "no info block\n");
532  		err = -ENOMEM;
533  		goto out_err;
534  	}
535  	info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
536  	if (info->num < 0) {
537  		err = info->num;
538  		goto out_err;
539  	}
540  	may_reduce = vcdev->revision > 0;
541  	vq = vring_create_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN,
542  				    vdev, true, may_reduce, ctx,
543  				    notify, callback, name);
544  
545  	if (!vq) {
546  		/* For now, we fail if we can't get the requested size. */
547  		dev_warn(&vcdev->cdev->dev, "no vq\n");
548  		err = -ENOMEM;
549  		goto out_err;
550  	}
551  
552  	vq->num_max = info->num;
553  
554  	/* it may have been reduced */
555  	info->num = virtqueue_get_vring_size(vq);
556  
557  	/* Register it with the host. */
558  	queue = virtqueue_get_desc_addr(vq);
559  	if (vcdev->revision == 0) {
560  		info->info_block->l.queue = queue;
561  		info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
562  		info->info_block->l.index = i;
563  		info->info_block->l.num = info->num;
564  		ccw->count = sizeof(info->info_block->l);
565  	} else {
566  		info->info_block->s.desc = queue;
567  		info->info_block->s.index = i;
568  		info->info_block->s.num = info->num;
569  		info->info_block->s.avail = (__u64)virtqueue_get_avail_addr(vq);
570  		info->info_block->s.used = (__u64)virtqueue_get_used_addr(vq);
571  		ccw->count = sizeof(info->info_block->s);
572  	}
573  	ccw->cmd_code = CCW_CMD_SET_VQ;
574  	ccw->flags = 0;
575  	ccw->cda = (__u32)virt_to_phys(info->info_block);
576  	err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
577  	if (err) {
578  		dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
579  		goto out_err;
580  	}
581  
582  	info->vq = vq;
583  	vq->priv = info;
584  
585  	/* Save it to our list. */
586  	spin_lock_irqsave(&vcdev->lock, flags);
587  	list_add(&info->node, &vcdev->virtqueues);
588  	spin_unlock_irqrestore(&vcdev->lock, flags);
589  
590  	return vq;
591  
592  out_err:
593  	if (vq)
594  		vring_del_virtqueue(vq);
595  	if (info) {
596  		ccw_device_dma_free(vcdev->cdev, info->info_block,
597  				    sizeof(*info->info_block));
598  	}
599  	kfree(info);
600  	return ERR_PTR(err);
601  }
602  
603  static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
604  					   struct virtqueue *vqs[], int nvqs,
605  					   struct ccw1 *ccw)
606  {
607  	int ret;
608  	struct virtio_thinint_area *thinint_area = NULL;
609  	unsigned long indicator_addr;
610  	struct airq_info *info;
611  
612  	thinint_area = ccw_device_dma_zalloc(vcdev->cdev,
613  					     sizeof(*thinint_area));
614  	if (!thinint_area) {
615  		ret = -ENOMEM;
616  		goto out;
617  	}
618  	/* Try to get an indicator. */
619  	indicator_addr = get_airq_indicator(vqs, nvqs,
620  					    &thinint_area->bit_nr,
621  					    &vcdev->airq_info);
622  	if (!indicator_addr) {
623  		ret = -ENOSPC;
624  		goto out;
625  	}
626  	thinint_area->indicator = virt_to_phys((void *)indicator_addr);
627  	info = vcdev->airq_info;
628  	thinint_area->summary_indicator =
629  		virt_to_phys(get_summary_indicator(info));
630  	thinint_area->isc = VIRTIO_AIRQ_ISC;
631  	ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
632  	ccw->flags = CCW_FLAG_SLI;
633  	ccw->count = sizeof(*thinint_area);
634  	ccw->cda = (__u32)virt_to_phys(thinint_area);
635  	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
636  	if (ret) {
637  		if (ret == -EOPNOTSUPP) {
638  			/*
639  			 * The host does not support adapter interrupts
640  			 * for virtio-ccw, stop trying.
641  			 */
642  			virtio_ccw_use_airq = 0;
643  			pr_info("Adapter interrupts unsupported on host\n");
644  		} else
645  			dev_warn(&vcdev->cdev->dev,
646  				 "enabling adapter interrupts = %d\n", ret);
647  		virtio_ccw_drop_indicators(vcdev);
648  	}
649  out:
650  	ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area));
651  	return ret;
652  }
653  
654  static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
655  			       struct virtqueue *vqs[],
656  			       vq_callback_t *callbacks[],
657  			       const char * const names[],
658  			       const bool *ctx,
659  			       struct irq_affinity *desc)
660  {
661  	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
662  	unsigned long *indicatorp = NULL;
663  	int ret, i, queue_idx = 0;
664  	struct ccw1 *ccw;
665  
666  	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
667  	if (!ccw)
668  		return -ENOMEM;
669  
670  	for (i = 0; i < nvqs; ++i) {
671  		if (!names[i]) {
672  			vqs[i] = NULL;
673  			continue;
674  		}
675  
676  		vqs[i] = virtio_ccw_setup_vq(vdev, queue_idx++, callbacks[i],
677  					     names[i], ctx ? ctx[i] : false,
678  					     ccw);
679  		if (IS_ERR(vqs[i])) {
680  			ret = PTR_ERR(vqs[i]);
681  			vqs[i] = NULL;
682  			goto out;
683  		}
684  	}
685  	ret = -ENOMEM;
686  	/*
687  	 * We need a data area under 2G to communicate. Our payload is
688  	 * the address of the indicators.
689  	*/
690  	indicatorp = ccw_device_dma_zalloc(vcdev->cdev,
691  					   sizeof(indicators(vcdev)));
692  	if (!indicatorp)
693  		goto out;
694  	*indicatorp = (unsigned long) indicators(vcdev);
695  	if (vcdev->is_thinint) {
696  		ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
697  		if (ret)
698  			/* no error, just fall back to legacy interrupts */
699  			vcdev->is_thinint = false;
700  	}
701  	if (!vcdev->is_thinint) {
702  		/* Register queue indicators with host. */
703  		*indicators(vcdev) = 0;
704  		ccw->cmd_code = CCW_CMD_SET_IND;
705  		ccw->flags = 0;
706  		ccw->count = sizeof(indicators(vcdev));
707  		ccw->cda = (__u32)virt_to_phys(indicatorp);
708  		ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
709  		if (ret)
710  			goto out;
711  	}
712  	/* Register indicators2 with host for config changes */
713  	*indicatorp = (unsigned long) indicators2(vcdev);
714  	*indicators2(vcdev) = 0;
715  	ccw->cmd_code = CCW_CMD_SET_CONF_IND;
716  	ccw->flags = 0;
717  	ccw->count = sizeof(indicators2(vcdev));
718  	ccw->cda = (__u32)virt_to_phys(indicatorp);
719  	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
720  	if (ret)
721  		goto out;
722  
723  	if (indicatorp)
724  		ccw_device_dma_free(vcdev->cdev, indicatorp,
725  				    sizeof(indicators(vcdev)));
726  	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
727  	return 0;
728  out:
729  	if (indicatorp)
730  		ccw_device_dma_free(vcdev->cdev, indicatorp,
731  				    sizeof(indicators(vcdev)));
732  	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
733  	virtio_ccw_del_vqs(vdev);
734  	return ret;
735  }
736  
737  static void virtio_ccw_reset(struct virtio_device *vdev)
738  {
739  	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
740  	struct ccw1 *ccw;
741  
742  	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
743  	if (!ccw)
744  		return;
745  
746  	/* Zero status bits. */
747  	vcdev->dma_area->status = 0;
748  
749  	/* Send a reset ccw on device. */
750  	ccw->cmd_code = CCW_CMD_VDEV_RESET;
751  	ccw->flags = 0;
752  	ccw->count = 0;
753  	ccw->cda = 0;
754  	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
755  	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
756  }
757  
758  static u64 virtio_ccw_get_features(struct virtio_device *vdev)
759  {
760  	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
761  	struct virtio_feature_desc *features;
762  	int ret;
763  	u64 rc;
764  	struct ccw1 *ccw;
765  
766  	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
767  	if (!ccw)
768  		return 0;
769  
770  	features = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*features));
771  	if (!features) {
772  		rc = 0;
773  		goto out_free;
774  	}
775  	/* Read the feature bits from the host. */
776  	features->index = 0;
777  	ccw->cmd_code = CCW_CMD_READ_FEAT;
778  	ccw->flags = 0;
779  	ccw->count = sizeof(*features);
780  	ccw->cda = (__u32)virt_to_phys(features);
781  	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
782  	if (ret) {
783  		rc = 0;
784  		goto out_free;
785  	}
786  
787  	rc = le32_to_cpu(features->features);
788  
789  	if (vcdev->revision == 0)
790  		goto out_free;
791  
792  	/* Read second half of the feature bits from the host. */
793  	features->index = 1;
794  	ccw->cmd_code = CCW_CMD_READ_FEAT;
795  	ccw->flags = 0;
796  	ccw->count = sizeof(*features);
797  	ccw->cda = (__u32)virt_to_phys(features);
798  	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
799  	if (ret == 0)
800  		rc |= (u64)le32_to_cpu(features->features) << 32;
801  
802  out_free:
803  	ccw_device_dma_free(vcdev->cdev, features, sizeof(*features));
804  	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
805  	return rc;
806  }
807  
808  static void ccw_transport_features(struct virtio_device *vdev)
809  {
810  	/*
811  	 * Currently nothing to do here.
812  	 */
813  }
814  
815  static int virtio_ccw_finalize_features(struct virtio_device *vdev)
816  {
817  	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
818  	struct virtio_feature_desc *features;
819  	struct ccw1 *ccw;
820  	int ret;
821  
822  	if (vcdev->revision >= 1 &&
823  	    !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
824  		dev_err(&vdev->dev, "virtio: device uses revision 1 "
825  			"but does not have VIRTIO_F_VERSION_1\n");
826  		return -EINVAL;
827  	}
828  
829  	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
830  	if (!ccw)
831  		return -ENOMEM;
832  
833  	features = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*features));
834  	if (!features) {
835  		ret = -ENOMEM;
836  		goto out_free;
837  	}
838  	/* Give virtio_ring a chance to accept features. */
839  	vring_transport_features(vdev);
840  
841  	/* Give virtio_ccw a chance to accept features. */
842  	ccw_transport_features(vdev);
843  
844  	features->index = 0;
845  	features->features = cpu_to_le32((u32)vdev->features);
846  	/* Write the first half of the feature bits to the host. */
847  	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
848  	ccw->flags = 0;
849  	ccw->count = sizeof(*features);
850  	ccw->cda = (__u32)virt_to_phys(features);
851  	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
852  	if (ret)
853  		goto out_free;
854  
855  	if (vcdev->revision == 0)
856  		goto out_free;
857  
858  	features->index = 1;
859  	features->features = cpu_to_le32(vdev->features >> 32);
860  	/* Write the second half of the feature bits to the host. */
861  	ccw->cmd_code = CCW_CMD_WRITE_FEAT;
862  	ccw->flags = 0;
863  	ccw->count = sizeof(*features);
864  	ccw->cda = (__u32)virt_to_phys(features);
865  	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
866  
867  out_free:
868  	ccw_device_dma_free(vcdev->cdev, features, sizeof(*features));
869  	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
870  
871  	return ret;
872  }
873  
874  static void virtio_ccw_get_config(struct virtio_device *vdev,
875  				  unsigned int offset, void *buf, unsigned len)
876  {
877  	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
878  	int ret;
879  	struct ccw1 *ccw;
880  	void *config_area;
881  	unsigned long flags;
882  
883  	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
884  	if (!ccw)
885  		return;
886  
887  	config_area = ccw_device_dma_zalloc(vcdev->cdev,
888  					    VIRTIO_CCW_CONFIG_SIZE);
889  	if (!config_area)
890  		goto out_free;
891  
892  	/* Read the config area from the host. */
893  	ccw->cmd_code = CCW_CMD_READ_CONF;
894  	ccw->flags = 0;
895  	ccw->count = offset + len;
896  	ccw->cda = (__u32)virt_to_phys(config_area);
897  	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
898  	if (ret)
899  		goto out_free;
900  
901  	spin_lock_irqsave(&vcdev->lock, flags);
902  	memcpy(vcdev->config, config_area, offset + len);
903  	if (vcdev->config_ready < offset + len)
904  		vcdev->config_ready = offset + len;
905  	spin_unlock_irqrestore(&vcdev->lock, flags);
906  	if (buf)
907  		memcpy(buf, config_area + offset, len);
908  
909  out_free:
910  	ccw_device_dma_free(vcdev->cdev, config_area, VIRTIO_CCW_CONFIG_SIZE);
911  	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
912  }
913  
914  static void virtio_ccw_set_config(struct virtio_device *vdev,
915  				  unsigned int offset, const void *buf,
916  				  unsigned len)
917  {
918  	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
919  	struct ccw1 *ccw;
920  	void *config_area;
921  	unsigned long flags;
922  
923  	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
924  	if (!ccw)
925  		return;
926  
927  	config_area = ccw_device_dma_zalloc(vcdev->cdev,
928  					    VIRTIO_CCW_CONFIG_SIZE);
929  	if (!config_area)
930  		goto out_free;
931  
932  	/* Make sure we don't overwrite fields. */
933  	if (vcdev->config_ready < offset)
934  		virtio_ccw_get_config(vdev, 0, NULL, offset);
935  	spin_lock_irqsave(&vcdev->lock, flags);
936  	memcpy(&vcdev->config[offset], buf, len);
937  	/* Write the config area to the host. */
938  	memcpy(config_area, vcdev->config, sizeof(vcdev->config));
939  	spin_unlock_irqrestore(&vcdev->lock, flags);
940  	ccw->cmd_code = CCW_CMD_WRITE_CONF;
941  	ccw->flags = 0;
942  	ccw->count = offset + len;
943  	ccw->cda = (__u32)virt_to_phys(config_area);
944  	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);
945  
946  out_free:
947  	ccw_device_dma_free(vcdev->cdev, config_area, VIRTIO_CCW_CONFIG_SIZE);
948  	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
949  }
950  
951  static u8 virtio_ccw_get_status(struct virtio_device *vdev)
952  {
953  	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
954  	u8 old_status = vcdev->dma_area->status;
955  	struct ccw1 *ccw;
956  
957  	if (vcdev->revision < 2)
958  		return vcdev->dma_area->status;
959  
960  	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
961  	if (!ccw)
962  		return old_status;
963  
964  	ccw->cmd_code = CCW_CMD_READ_STATUS;
965  	ccw->flags = 0;
966  	ccw->count = sizeof(vcdev->dma_area->status);
967  	ccw->cda = (__u32)virt_to_phys(&vcdev->dma_area->status);
968  	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_STATUS);
969  /*
970   * If the channel program failed (should only happen if the device
971   * was hotunplugged, and then we clean up via the machine check
972   * handler anyway), vcdev->dma_area->status was not overwritten and we just
973   * return the old status, which is fine.
974  */
975  	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
976  
977  	return vcdev->dma_area->status;
978  }
979  
980  static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
981  {
982  	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
983  	u8 old_status = vcdev->dma_area->status;
984  	struct ccw1 *ccw;
985  	int ret;
986  
987  	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
988  	if (!ccw)
989  		return;
990  
991  	/* Write the status to the host. */
992  	vcdev->dma_area->status = status;
993  	ccw->cmd_code = CCW_CMD_WRITE_STATUS;
994  	ccw->flags = 0;
995  	ccw->count = sizeof(status);
996  	ccw->cda = (__u32)virt_to_phys(&vcdev->dma_area->status);
997  	/* We use ssch for setting the status which is a serializing
998  	 * instruction that guarantees the memory writes have
999  	 * completed before ssch.
1000  	 */
1001  	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
1002  	/* Write failed? We assume status is unchanged. */
1003  	if (ret)
1004  		vcdev->dma_area->status = old_status;
1005  	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1006  }
1007  
1008  static const char *virtio_ccw_bus_name(struct virtio_device *vdev)
1009  {
1010  	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
1011  
1012  	return dev_name(&vcdev->cdev->dev);
1013  }
1014  
1015  static void virtio_ccw_synchronize_cbs(struct virtio_device *vdev)
1016  {
1017  	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
1018  	struct airq_info *info = vcdev->airq_info;
1019  
1020  	if (info) {
1021  		/*
1022  		 * This device uses adapter interrupts: synchronize with
1023  		 * vring_interrupt() called by virtio_airq_handler()
1024  		 * via the indicator area lock.
1025  		 */
1026  		write_lock_irq(&info->lock);
1027  		write_unlock_irq(&info->lock);
1028  	} else {
1029  		/* This device uses classic interrupts: synchronize
1030  		 * with vring_interrupt() called by
1031  		 * virtio_ccw_int_handler() via the per-device
1032  		 * irq_lock
1033  		 */
1034  		write_lock_irq(&vcdev->irq_lock);
1035  		write_unlock_irq(&vcdev->irq_lock);
1036  	}
1037  }
1038  
1039  static const struct virtio_config_ops virtio_ccw_config_ops = {
1040  	.get_features = virtio_ccw_get_features,
1041  	.finalize_features = virtio_ccw_finalize_features,
1042  	.get = virtio_ccw_get_config,
1043  	.set = virtio_ccw_set_config,
1044  	.get_status = virtio_ccw_get_status,
1045  	.set_status = virtio_ccw_set_status,
1046  	.reset = virtio_ccw_reset,
1047  	.find_vqs = virtio_ccw_find_vqs,
1048  	.del_vqs = virtio_ccw_del_vqs,
1049  	.bus_name = virtio_ccw_bus_name,
1050  	.synchronize_cbs = virtio_ccw_synchronize_cbs,
1051  };
1052  
1053  
1054  /*
1055   * ccw bus driver related functions
1056   */
1057  
1058  static void virtio_ccw_release_dev(struct device *_d)
1059  {
1060  	struct virtio_device *dev = dev_to_virtio(_d);
1061  	struct virtio_ccw_device *vcdev = to_vc_device(dev);
1062  
1063  	ccw_device_dma_free(vcdev->cdev, vcdev->dma_area,
1064  			    sizeof(*vcdev->dma_area));
1065  	kfree(vcdev);
1066  }
1067  
1068  static int irb_is_error(struct irb *irb)
1069  {
1070  	if (scsw_cstat(&irb->scsw) != 0)
1071  		return 1;
1072  	if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))
1073  		return 1;
1074  	if (scsw_cc(&irb->scsw) != 0)
1075  		return 1;
1076  	return 0;
1077  }
1078  
1079  static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
1080  					      int index)
1081  {
1082  	struct virtio_ccw_vq_info *info;
1083  	unsigned long flags;
1084  	struct virtqueue *vq;
1085  
1086  	vq = NULL;
1087  	spin_lock_irqsave(&vcdev->lock, flags);
1088  	list_for_each_entry(info, &vcdev->virtqueues, node) {
1089  		if (info->vq->index == index) {
1090  			vq = info->vq;
1091  			break;
1092  		}
1093  	}
1094  	spin_unlock_irqrestore(&vcdev->lock, flags);
1095  	return vq;
1096  }
1097  
1098  static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev,
1099  				      __u32 activity)
1100  {
1101  	if (vcdev->curr_io & activity) {
1102  		switch (activity) {
1103  		case VIRTIO_CCW_DOING_READ_FEAT:
1104  		case VIRTIO_CCW_DOING_WRITE_FEAT:
1105  		case VIRTIO_CCW_DOING_READ_CONFIG:
1106  		case VIRTIO_CCW_DOING_WRITE_CONFIG:
1107  		case VIRTIO_CCW_DOING_WRITE_STATUS:
1108  		case VIRTIO_CCW_DOING_READ_STATUS:
1109  		case VIRTIO_CCW_DOING_SET_VQ:
1110  		case VIRTIO_CCW_DOING_SET_IND:
1111  		case VIRTIO_CCW_DOING_SET_CONF_IND:
1112  		case VIRTIO_CCW_DOING_RESET:
1113  		case VIRTIO_CCW_DOING_READ_VQ_CONF:
1114  		case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
1115  		case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
1116  			vcdev->curr_io &= ~activity;
1117  			wake_up(&vcdev->wait_q);
1118  			break;
1119  		default:
1120  			/* don't know what to do... */
1121  			dev_warn(&vcdev->cdev->dev,
1122  				 "Suspicious activity '%08x'\n", activity);
1123  			WARN_ON(1);
1124  			break;
1125  		}
1126  	}
1127  }
1128  
1129  static void virtio_ccw_int_handler(struct ccw_device *cdev,
1130  				   unsigned long intparm,
1131  				   struct irb *irb)
1132  {
1133  	__u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;
1134  	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1135  	int i;
1136  	struct virtqueue *vq;
1137  
1138  	if (!vcdev)
1139  		return;
1140  	if (IS_ERR(irb)) {
1141  		vcdev->err = PTR_ERR(irb);
1142  		virtio_ccw_check_activity(vcdev, activity);
1143  		/* Don't poke around indicators, something's wrong. */
1144  		return;
1145  	}
1146  	/* Check if it's a notification from the host. */
1147  	if ((intparm == 0) &&
1148  	    (scsw_stctl(&irb->scsw) ==
1149  	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {
1150  		/* OK */
1151  	}
1152  	if (irb_is_error(irb)) {
1153  		/* Command reject? */
1154  		if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
1155  		    (irb->ecw[0] & SNS0_CMD_REJECT))
1156  			vcdev->err = -EOPNOTSUPP;
1157  		else
1158  			/* Map everything else to -EIO. */
1159  			vcdev->err = -EIO;
1160  	}
1161  	virtio_ccw_check_activity(vcdev, activity);
1162  #ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
1163  	/*
1164  	 * Paired with virtio_ccw_synchronize_cbs() and interrupts are
1165  	 * disabled here.
1166  	 */
1167  	read_lock(&vcdev->irq_lock);
1168  #endif
1169  	for_each_set_bit(i, indicators(vcdev),
1170  			 sizeof(*indicators(vcdev)) * BITS_PER_BYTE) {
1171  		/* The bit clear must happen before the vring kick. */
1172  		clear_bit(i, indicators(vcdev));
1173  		barrier();
1174  		vq = virtio_ccw_vq_by_ind(vcdev, i);
1175  		vring_interrupt(0, vq);
1176  	}
1177  #ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
1178  	read_unlock(&vcdev->irq_lock);
1179  #endif
1180  	if (test_bit(0, indicators2(vcdev))) {
1181  		virtio_config_changed(&vcdev->vdev);
1182  		clear_bit(0, indicators2(vcdev));
1183  	}
1184  }
1185  
1186  /*
1187   * We usually want to autoonline all devices, but give the admin
1188   * a way to exempt devices from this.
1189   */
1190  #define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
1191  		     (8*sizeof(long)))
1192  static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];
1193  
1194  static char *no_auto = "";
1195  
1196  module_param(no_auto, charp, 0444);
1197  MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");
1198  
1199  static int virtio_ccw_check_autoonline(struct ccw_device *cdev)
1200  {
1201  	struct ccw_dev_id id;
1202  
1203  	ccw_device_get_id(cdev, &id);
1204  	if (test_bit(id.devno, devs_no_auto[id.ssid]))
1205  		return 0;
1206  	return 1;
1207  }
1208  
1209  static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)
1210  {
1211  	struct ccw_device *cdev = data;
1212  	int ret;
1213  
1214  	ret = ccw_device_set_online(cdev);
1215  	if (ret)
1216  		dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);
1217  }
1218  
1219  static int virtio_ccw_probe(struct ccw_device *cdev)
1220  {
1221  	cdev->handler = virtio_ccw_int_handler;
1222  
1223  	if (virtio_ccw_check_autoonline(cdev))
1224  		async_schedule(virtio_ccw_auto_online, cdev);
1225  	return 0;
1226  }
1227  
1228  static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
1229  {
1230  	unsigned long flags;
1231  	struct virtio_ccw_device *vcdev;
1232  
1233  	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1234  	vcdev = dev_get_drvdata(&cdev->dev);
1235  	if (!vcdev || vcdev->going_away) {
1236  		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1237  		return NULL;
1238  	}
1239  	vcdev->going_away = true;
1240  	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1241  	return vcdev;
1242  }
1243  
1244  static void virtio_ccw_remove(struct ccw_device *cdev)
1245  {
1246  	unsigned long flags;
1247  	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1248  
1249  	if (vcdev && cdev->online) {
1250  		if (vcdev->device_lost)
1251  			virtio_break_device(&vcdev->vdev);
1252  		unregister_virtio_device(&vcdev->vdev);
1253  		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1254  		dev_set_drvdata(&cdev->dev, NULL);
1255  		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1256  	}
1257  	cdev->handler = NULL;
1258  }
1259  
1260  static int virtio_ccw_offline(struct ccw_device *cdev)
1261  {
1262  	unsigned long flags;
1263  	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1264  
1265  	if (!vcdev)
1266  		return 0;
1267  	if (vcdev->device_lost)
1268  		virtio_break_device(&vcdev->vdev);
1269  	unregister_virtio_device(&vcdev->vdev);
1270  	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1271  	dev_set_drvdata(&cdev->dev, NULL);
1272  	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1273  	return 0;
1274  }
1275  
1276  static int virtio_ccw_set_transport_rev(struct virtio_ccw_device *vcdev)
1277  {
1278  	struct virtio_rev_info *rev;
1279  	struct ccw1 *ccw;
1280  	int ret;
1281  
1282  	ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw));
1283  	if (!ccw)
1284  		return -ENOMEM;
1285  	rev = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*rev));
1286  	if (!rev) {
1287  		ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1288  		return -ENOMEM;
1289  	}
1290  
1291  	/* Set transport revision */
1292  	ccw->cmd_code = CCW_CMD_SET_VIRTIO_REV;
1293  	ccw->flags = 0;
1294  	ccw->count = sizeof(*rev);
1295  	ccw->cda = (__u32)virt_to_phys(rev);
1296  
1297  	vcdev->revision = VIRTIO_CCW_REV_MAX;
1298  	do {
1299  		rev->revision = vcdev->revision;
1300  		/* none of our supported revisions carry payload */
1301  		rev->length = 0;
1302  		ret = ccw_io_helper(vcdev, ccw,
1303  				    VIRTIO_CCW_DOING_SET_VIRTIO_REV);
1304  		if (ret == -EOPNOTSUPP) {
1305  			if (vcdev->revision == 0)
1306  				/*
1307  				 * The host device does not support setting
1308  				 * the revision: let's operate it in legacy
1309  				 * mode.
1310  				 */
1311  				ret = 0;
1312  			else
1313  				vcdev->revision--;
1314  		}
1315  	} while (ret == -EOPNOTSUPP);
1316  
1317  	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
1318  	ccw_device_dma_free(vcdev->cdev, rev, sizeof(*rev));
1319  	return ret;
1320  }
1321  
1322  static int virtio_ccw_online(struct ccw_device *cdev)
1323  {
1324  	int ret;
1325  	struct virtio_ccw_device *vcdev;
1326  	unsigned long flags;
1327  
1328  	vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
1329  	if (!vcdev) {
1330  		dev_warn(&cdev->dev, "Could not get memory for virtio\n");
1331  		ret = -ENOMEM;
1332  		goto out_free;
1333  	}
1334  	vcdev->vdev.dev.parent = &cdev->dev;
1335  	vcdev->cdev = cdev;
1336  	vcdev->dma_area = ccw_device_dma_zalloc(vcdev->cdev,
1337  						sizeof(*vcdev->dma_area));
1338  	if (!vcdev->dma_area) {
1339  		ret = -ENOMEM;
1340  		goto out_free;
1341  	}
1342  
1343  	vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */
1344  
1345  	vcdev->vdev.dev.release = virtio_ccw_release_dev;
1346  	vcdev->vdev.config = &virtio_ccw_config_ops;
1347  	init_waitqueue_head(&vcdev->wait_q);
1348  	INIT_LIST_HEAD(&vcdev->virtqueues);
1349  	spin_lock_init(&vcdev->lock);
1350  	rwlock_init(&vcdev->irq_lock);
1351  	mutex_init(&vcdev->io_lock);
1352  
1353  	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1354  	dev_set_drvdata(&cdev->dev, vcdev);
1355  	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1356  	vcdev->vdev.id.vendor = cdev->id.cu_type;
1357  	vcdev->vdev.id.device = cdev->id.cu_model;
1358  
1359  	ret = virtio_ccw_set_transport_rev(vcdev);
1360  	if (ret)
1361  		goto out_free;
1362  
1363  	ret = register_virtio_device(&vcdev->vdev);
1364  	if (ret) {
1365  		dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",
1366  			 ret);
1367  		goto out_put;
1368  	}
1369  	return 0;
1370  out_put:
1371  	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1372  	dev_set_drvdata(&cdev->dev, NULL);
1373  	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1374  	put_device(&vcdev->vdev.dev);
1375  	return ret;
1376  out_free:
1377  	if (vcdev) {
1378  		ccw_device_dma_free(vcdev->cdev, vcdev->dma_area,
1379  				    sizeof(*vcdev->dma_area));
1380  	}
1381  	kfree(vcdev);
1382  	return ret;
1383  }
1384  
1385  static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
1386  {
1387  	int rc;
1388  	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);
1389  
1390  	/*
1391  	 * Make sure vcdev is set
1392  	 * i.e. set_offline/remove callback not already running
1393  	 */
1394  	if (!vcdev)
1395  		return NOTIFY_DONE;
1396  
1397  	switch (event) {
1398  	case CIO_GONE:
1399  		vcdev->device_lost = true;
1400  		rc = NOTIFY_DONE;
1401  		break;
1402  	case CIO_OPER:
1403  		rc = NOTIFY_OK;
1404  		break;
1405  	default:
1406  		rc = NOTIFY_DONE;
1407  		break;
1408  	}
1409  	return rc;
1410  }
1411  
1412  static struct ccw_device_id virtio_ids[] = {
1413  	{ CCW_DEVICE(0x3832, 0) },
1414  	{},
1415  };
1416  
1417  static struct ccw_driver virtio_ccw_driver = {
1418  	.driver = {
1419  		.owner = THIS_MODULE,
1420  		.name = "virtio_ccw",
1421  	},
1422  	.ids = virtio_ids,
1423  	.probe = virtio_ccw_probe,
1424  	.remove = virtio_ccw_remove,
1425  	.set_offline = virtio_ccw_offline,
1426  	.set_online = virtio_ccw_online,
1427  	.notify = virtio_ccw_cio_notify,
1428  	.int_class = IRQIO_VIR,
1429  };
1430  
1431  static int __init pure_hex(char **cp, unsigned int *val, int min_digit,
1432  			   int max_digit, int max_val)
1433  {
1434  	int diff;
1435  
1436  	diff = 0;
1437  	*val = 0;
1438  
1439  	while (diff <= max_digit) {
1440  		int value = hex_to_bin(**cp);
1441  
1442  		if (value < 0)
1443  			break;
1444  		*val = *val * 16 + value;
1445  		(*cp)++;
1446  		diff++;
1447  	}
1448  
1449  	if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
1450  		return 1;
1451  
1452  	return 0;
1453  }
1454  
1455  static int __init parse_busid(char *str, unsigned int *cssid,
1456  			      unsigned int *ssid, unsigned int *devno)
1457  {
1458  	char *str_work;
1459  	int rc, ret;
1460  
1461  	rc = 1;
1462  
1463  	if (*str == '\0')
1464  		goto out;
1465  
1466  	str_work = str;
1467  	ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
1468  	if (ret || (str_work[0] != '.'))
1469  		goto out;
1470  	str_work++;
1471  	ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
1472  	if (ret || (str_work[0] != '.'))
1473  		goto out;
1474  	str_work++;
1475  	ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
1476  	if (ret || (str_work[0] != '\0'))
1477  		goto out;
1478  
1479  	rc = 0;
1480  out:
1481  	return rc;
1482  }
1483  
1484  static void __init no_auto_parse(void)
1485  {
1486  	unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
1487  	char *parm, *str;
1488  	int rc;
1489  
1490  	str = no_auto;
1491  	while ((parm = strsep(&str, ","))) {
1492  		rc = parse_busid(strsep(&parm, "-"), &from_cssid,
1493  				 &from_ssid, &from);
1494  		if (rc)
1495  			continue;
1496  		if (parm != NULL) {
1497  			rc = parse_busid(parm, &to_cssid,
1498  					 &to_ssid, &to);
1499  			if ((from_ssid > to_ssid) ||
1500  			    ((from_ssid == to_ssid) && (from > to)))
1501  				rc = -EINVAL;
1502  		} else {
1503  			to_cssid = from_cssid;
1504  			to_ssid = from_ssid;
1505  			to = from;
1506  		}
1507  		if (rc)
1508  			continue;
1509  		while ((from_ssid < to_ssid) ||
1510  		       ((from_ssid == to_ssid) && (from <= to))) {
1511  			set_bit(from, devs_no_auto[from_ssid]);
1512  			from++;
1513  			if (from > __MAX_SUBCHANNEL) {
1514  				from_ssid++;
1515  				from = 0;
1516  			}
1517  		}
1518  	}
1519  }
1520  
1521  static int __init virtio_ccw_init(void)
1522  {
1523  	int rc;
1524  
1525  	/* parse no_auto string before we do anything further */
1526  	no_auto_parse();
1527  
1528  	summary_indicators = cio_dma_zalloc(MAX_AIRQ_AREAS);
1529  	if (!summary_indicators)
1530  		return -ENOMEM;
1531  	rc = ccw_driver_register(&virtio_ccw_driver);
1532  	if (rc)
1533  		cio_dma_free(summary_indicators, MAX_AIRQ_AREAS);
1534  	return rc;
1535  }
1536  device_initcall(virtio_ccw_init);
1537