xref: /linux/drivers/virtio/virtio_pci_modern_dev.c (revision 335bbdf01d25517ae832ac1807fd8323c1f4f3b9)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 
3 #include <linux/virtio_pci_modern.h>
4 #include <linux/module.h>
5 #include <linux/pci.h>
6 #include <linux/delay.h>
7 
8 /*
9  * vp_modern_map_capability - map a part of virtio pci capability
10  * @mdev: the modern virtio-pci device
11  * @off: offset of the capability
12  * @minlen: minimal length of the capability
13  * @align: align requirement
14  * @start: start from the capability
15  * @size: map size
16  * @len: the length that is actually mapped
17  * @pa: physical address of the capability
18  *
19  * Returns the io address of for the part of the capability
20  */
21 static void __iomem *
22 vp_modern_map_capability(struct virtio_pci_modern_device *mdev, int off,
23 			 size_t minlen, u32 align, u32 start, u32 size,
24 			 size_t *len, resource_size_t *pa)
25 {
26 	struct pci_dev *dev = mdev->pci_dev;
27 	u8 bar;
28 	u32 offset, length;
29 	void __iomem *p;
30 
31 	pci_read_config_byte(dev, off + offsetof(struct virtio_pci_cap,
32 						 bar),
33 			     &bar);
34 	pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, offset),
35 			     &offset);
36 	pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, length),
37 			      &length);
38 
39 	/* Check if the BAR may have changed since we requested the region. */
40 	if (bar >= PCI_STD_NUM_BARS || !(mdev->modern_bars & (1 << bar))) {
41 		dev_err(&dev->dev,
42 			"virtio_pci: bar unexpectedly changed to %u\n", bar);
43 		return NULL;
44 	}
45 
46 	if (length <= start) {
47 		dev_err(&dev->dev,
48 			"virtio_pci: bad capability len %u (>%u expected)\n",
49 			length, start);
50 		return NULL;
51 	}
52 
53 	if (length - start < minlen) {
54 		dev_err(&dev->dev,
55 			"virtio_pci: bad capability len %u (>=%zu expected)\n",
56 			length, minlen);
57 		return NULL;
58 	}
59 
60 	length -= start;
61 
62 	if (start + offset < offset) {
63 		dev_err(&dev->dev,
64 			"virtio_pci: map wrap-around %u+%u\n",
65 			start, offset);
66 		return NULL;
67 	}
68 
69 	offset += start;
70 
71 	if (offset & (align - 1)) {
72 		dev_err(&dev->dev,
73 			"virtio_pci: offset %u not aligned to %u\n",
74 			offset, align);
75 		return NULL;
76 	}
77 
78 	if (length > size)
79 		length = size;
80 
81 	if (len)
82 		*len = length;
83 
84 	if (minlen + offset < minlen ||
85 	    minlen + offset > pci_resource_len(dev, bar)) {
86 		dev_err(&dev->dev,
87 			"virtio_pci: map virtio %zu@%u "
88 			"out of range on bar %i length %lu\n",
89 			minlen, offset,
90 			bar, (unsigned long)pci_resource_len(dev, bar));
91 		return NULL;
92 	}
93 
94 	p = pci_iomap_range(dev, bar, offset, length);
95 	if (!p)
96 		dev_err(&dev->dev,
97 			"virtio_pci: unable to map virtio %u@%u on bar %i\n",
98 			length, offset, bar);
99 	else if (pa)
100 		*pa = pci_resource_start(dev, bar) + offset;
101 
102 	return p;
103 }
104 
105 /**
106  * virtio_pci_find_capability - walk capabilities to find device info.
107  * @dev: the pci device
108  * @cfg_type: the VIRTIO_PCI_CAP_* value we seek
109  * @ioresource_types: IORESOURCE_MEM and/or IORESOURCE_IO.
110  * @bars: the bitmask of BARs
111  *
112  * Returns offset of the capability, or 0.
113  */
114 static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type,
115 					     u32 ioresource_types, int *bars)
116 {
117 	int pos;
118 
119 	for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
120 	     pos > 0;
121 	     pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) {
122 		u8 type, bar;
123 		pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
124 							 cfg_type),
125 				     &type);
126 		pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
127 							 bar),
128 				     &bar);
129 
130 		/* Ignore structures with reserved BAR values */
131 		if (bar >= PCI_STD_NUM_BARS)
132 			continue;
133 
134 		if (type == cfg_type) {
135 			if (pci_resource_len(dev, bar) &&
136 			    pci_resource_flags(dev, bar) & ioresource_types) {
137 				*bars |= (1 << bar);
138 				return pos;
139 			}
140 		}
141 	}
142 	return 0;
143 }
144 
145 /* This is part of the ABI.  Don't screw with it. */
146 static inline void check_offsets(void)
147 {
148 	/* Note: disk space was harmed in compilation of this function. */
149 	BUILD_BUG_ON(VIRTIO_PCI_CAP_VNDR !=
150 		     offsetof(struct virtio_pci_cap, cap_vndr));
151 	BUILD_BUG_ON(VIRTIO_PCI_CAP_NEXT !=
152 		     offsetof(struct virtio_pci_cap, cap_next));
153 	BUILD_BUG_ON(VIRTIO_PCI_CAP_LEN !=
154 		     offsetof(struct virtio_pci_cap, cap_len));
155 	BUILD_BUG_ON(VIRTIO_PCI_CAP_CFG_TYPE !=
156 		     offsetof(struct virtio_pci_cap, cfg_type));
157 	BUILD_BUG_ON(VIRTIO_PCI_CAP_BAR !=
158 		     offsetof(struct virtio_pci_cap, bar));
159 	BUILD_BUG_ON(VIRTIO_PCI_CAP_OFFSET !=
160 		     offsetof(struct virtio_pci_cap, offset));
161 	BUILD_BUG_ON(VIRTIO_PCI_CAP_LENGTH !=
162 		     offsetof(struct virtio_pci_cap, length));
163 	BUILD_BUG_ON(VIRTIO_PCI_NOTIFY_CAP_MULT !=
164 		     offsetof(struct virtio_pci_notify_cap,
165 			      notify_off_multiplier));
166 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_DFSELECT !=
167 		     offsetof(struct virtio_pci_common_cfg,
168 			      device_feature_select));
169 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_DF !=
170 		     offsetof(struct virtio_pci_common_cfg, device_feature));
171 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_GFSELECT !=
172 		     offsetof(struct virtio_pci_common_cfg,
173 			      guest_feature_select));
174 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_GF !=
175 		     offsetof(struct virtio_pci_common_cfg, guest_feature));
176 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_MSIX !=
177 		     offsetof(struct virtio_pci_common_cfg, msix_config));
178 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_NUMQ !=
179 		     offsetof(struct virtio_pci_common_cfg, num_queues));
180 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_STATUS !=
181 		     offsetof(struct virtio_pci_common_cfg, device_status));
182 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_CFGGENERATION !=
183 		     offsetof(struct virtio_pci_common_cfg, config_generation));
184 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SELECT !=
185 		     offsetof(struct virtio_pci_common_cfg, queue_select));
186 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SIZE !=
187 		     offsetof(struct virtio_pci_common_cfg, queue_size));
188 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_MSIX !=
189 		     offsetof(struct virtio_pci_common_cfg, queue_msix_vector));
190 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_ENABLE !=
191 		     offsetof(struct virtio_pci_common_cfg, queue_enable));
192 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_NOFF !=
193 		     offsetof(struct virtio_pci_common_cfg, queue_notify_off));
194 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCLO !=
195 		     offsetof(struct virtio_pci_common_cfg, queue_desc_lo));
196 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCHI !=
197 		     offsetof(struct virtio_pci_common_cfg, queue_desc_hi));
198 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILLO !=
199 		     offsetof(struct virtio_pci_common_cfg, queue_avail_lo));
200 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILHI !=
201 		     offsetof(struct virtio_pci_common_cfg, queue_avail_hi));
202 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDLO !=
203 		     offsetof(struct virtio_pci_common_cfg, queue_used_lo));
204 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDHI !=
205 		     offsetof(struct virtio_pci_common_cfg, queue_used_hi));
206 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_NDATA !=
207 		     offsetof(struct virtio_pci_modern_common_cfg, queue_notify_data));
208 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_RESET !=
209 		     offsetof(struct virtio_pci_modern_common_cfg, queue_reset));
210 }
211 
212 /*
213  * vp_modern_probe: probe the modern virtio pci device, note that the
214  * caller is required to enable PCI device before calling this function.
215  * @mdev: the modern virtio-pci device
216  *
217  * Return 0 on succeed otherwise fail
218  */
219 int vp_modern_probe(struct virtio_pci_modern_device *mdev)
220 {
221 	struct pci_dev *pci_dev = mdev->pci_dev;
222 	int err, common, isr, notify, device;
223 	u32 notify_length;
224 	u32 notify_offset;
225 	int devid;
226 
227 	check_offsets();
228 
229 	if (mdev->device_id_check) {
230 		devid = mdev->device_id_check(pci_dev);
231 		if (devid < 0)
232 			return devid;
233 		mdev->id.device = devid;
234 	} else {
235 		/* We only own devices >= 0x1000 and <= 0x107f: leave the rest. */
236 		if (pci_dev->device < 0x1000 || pci_dev->device > 0x107f)
237 			return -ENODEV;
238 
239 		if (pci_dev->device < 0x1040) {
240 			/* Transitional devices: use the PCI subsystem device id as
241 			 * virtio device id, same as legacy driver always did.
242 			 */
243 			mdev->id.device = pci_dev->subsystem_device;
244 		} else {
245 			/* Modern devices: simply use PCI device id, but start from 0x1040. */
246 			mdev->id.device = pci_dev->device - 0x1040;
247 		}
248 	}
249 	mdev->id.vendor = pci_dev->subsystem_vendor;
250 
251 	/* check for a common config: if not, use legacy mode (bar 0). */
252 	common = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG,
253 					    IORESOURCE_IO | IORESOURCE_MEM,
254 					    &mdev->modern_bars);
255 	if (!common) {
256 		dev_info(&pci_dev->dev,
257 			 "virtio_pci: leaving for legacy driver\n");
258 		return -ENODEV;
259 	}
260 
261 	/* If common is there, these should be too... */
262 	isr = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_ISR_CFG,
263 					 IORESOURCE_IO | IORESOURCE_MEM,
264 					 &mdev->modern_bars);
265 	notify = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG,
266 					    IORESOURCE_IO | IORESOURCE_MEM,
267 					    &mdev->modern_bars);
268 	if (!isr || !notify) {
269 		dev_err(&pci_dev->dev,
270 			"virtio_pci: missing capabilities %i/%i/%i\n",
271 			common, isr, notify);
272 		return -EINVAL;
273 	}
274 
275 	err = dma_set_mask_and_coherent(&pci_dev->dev,
276 					mdev->dma_mask ? : DMA_BIT_MASK(64));
277 	if (err)
278 		err = dma_set_mask_and_coherent(&pci_dev->dev,
279 						DMA_BIT_MASK(32));
280 	if (err)
281 		dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA.  Trying to continue, but this might not work.\n");
282 
283 	/* Device capability is only mandatory for devices that have
284 	 * device-specific configuration.
285 	 */
286 	device = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_DEVICE_CFG,
287 					    IORESOURCE_IO | IORESOURCE_MEM,
288 					    &mdev->modern_bars);
289 
290 	err = pci_request_selected_regions(pci_dev, mdev->modern_bars,
291 					   "virtio-pci-modern");
292 	if (err)
293 		return err;
294 
295 	err = -EINVAL;
296 	mdev->common = vp_modern_map_capability(mdev, common,
297 				      sizeof(struct virtio_pci_common_cfg), 4,
298 				      0, sizeof(struct virtio_pci_modern_common_cfg),
299 				      &mdev->common_len, NULL);
300 	if (!mdev->common)
301 		goto err_map_common;
302 	mdev->isr = vp_modern_map_capability(mdev, isr, sizeof(u8), 1,
303 					     0, 1,
304 					     NULL, NULL);
305 	if (!mdev->isr)
306 		goto err_map_isr;
307 
308 	/* Read notify_off_multiplier from config space. */
309 	pci_read_config_dword(pci_dev,
310 			      notify + offsetof(struct virtio_pci_notify_cap,
311 						notify_off_multiplier),
312 			      &mdev->notify_offset_multiplier);
313 	/* Read notify length and offset from config space. */
314 	pci_read_config_dword(pci_dev,
315 			      notify + offsetof(struct virtio_pci_notify_cap,
316 						cap.length),
317 			      &notify_length);
318 
319 	pci_read_config_dword(pci_dev,
320 			      notify + offsetof(struct virtio_pci_notify_cap,
321 						cap.offset),
322 			      &notify_offset);
323 
324 	/* We don't know how many VQs we'll map, ahead of the time.
325 	 * If notify length is small, map it all now.
326 	 * Otherwise, map each VQ individually later.
327 	 */
328 	if ((u64)notify_length + (notify_offset % PAGE_SIZE) <= PAGE_SIZE) {
329 		mdev->notify_base = vp_modern_map_capability(mdev, notify,
330 							     2, 2,
331 							     0, notify_length,
332 							     &mdev->notify_len,
333 							     &mdev->notify_pa);
334 		if (!mdev->notify_base)
335 			goto err_map_notify;
336 	} else {
337 		mdev->notify_map_cap = notify;
338 	}
339 
340 	/* Again, we don't know how much we should map, but PAGE_SIZE
341 	 * is more than enough for all existing devices.
342 	 */
343 	if (device) {
344 		mdev->device = vp_modern_map_capability(mdev, device, 0, 4,
345 							0, PAGE_SIZE,
346 							&mdev->device_len,
347 							NULL);
348 		if (!mdev->device)
349 			goto err_map_device;
350 	}
351 
352 	return 0;
353 
354 err_map_device:
355 	if (mdev->notify_base)
356 		pci_iounmap(pci_dev, mdev->notify_base);
357 err_map_notify:
358 	pci_iounmap(pci_dev, mdev->isr);
359 err_map_isr:
360 	pci_iounmap(pci_dev, mdev->common);
361 err_map_common:
362 	pci_release_selected_regions(pci_dev, mdev->modern_bars);
363 	return err;
364 }
365 EXPORT_SYMBOL_GPL(vp_modern_probe);
366 
367 /*
368  * vp_modern_remove: remove and cleanup the modern virtio pci device
369  * @mdev: the modern virtio-pci device
370  */
371 void vp_modern_remove(struct virtio_pci_modern_device *mdev)
372 {
373 	struct pci_dev *pci_dev = mdev->pci_dev;
374 
375 	if (mdev->device)
376 		pci_iounmap(pci_dev, mdev->device);
377 	if (mdev->notify_base)
378 		pci_iounmap(pci_dev, mdev->notify_base);
379 	pci_iounmap(pci_dev, mdev->isr);
380 	pci_iounmap(pci_dev, mdev->common);
381 	pci_release_selected_regions(pci_dev, mdev->modern_bars);
382 }
383 EXPORT_SYMBOL_GPL(vp_modern_remove);
384 
385 /*
386  * vp_modern_get_features - get features from device
387  * @mdev: the modern virtio-pci device
388  *
389  * Returns the features read from the device
390  */
391 u64 vp_modern_get_features(struct virtio_pci_modern_device *mdev)
392 {
393 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
394 
395 	u64 features;
396 
397 	vp_iowrite32(0, &cfg->device_feature_select);
398 	features = vp_ioread32(&cfg->device_feature);
399 	vp_iowrite32(1, &cfg->device_feature_select);
400 	features |= ((u64)vp_ioread32(&cfg->device_feature) << 32);
401 
402 	return features;
403 }
404 EXPORT_SYMBOL_GPL(vp_modern_get_features);
405 
406 /*
407  * vp_modern_get_driver_features - get driver features from device
408  * @mdev: the modern virtio-pci device
409  *
410  * Returns the driver features read from the device
411  */
412 u64 vp_modern_get_driver_features(struct virtio_pci_modern_device *mdev)
413 {
414 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
415 
416 	u64 features;
417 
418 	vp_iowrite32(0, &cfg->guest_feature_select);
419 	features = vp_ioread32(&cfg->guest_feature);
420 	vp_iowrite32(1, &cfg->guest_feature_select);
421 	features |= ((u64)vp_ioread32(&cfg->guest_feature) << 32);
422 
423 	return features;
424 }
425 EXPORT_SYMBOL_GPL(vp_modern_get_driver_features);
426 
427 /*
428  * vp_modern_set_features - set features to device
429  * @mdev: the modern virtio-pci device
430  * @features: the features set to device
431  */
432 void vp_modern_set_features(struct virtio_pci_modern_device *mdev,
433 			    u64 features)
434 {
435 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
436 
437 	vp_iowrite32(0, &cfg->guest_feature_select);
438 	vp_iowrite32((u32)features, &cfg->guest_feature);
439 	vp_iowrite32(1, &cfg->guest_feature_select);
440 	vp_iowrite32(features >> 32, &cfg->guest_feature);
441 }
442 EXPORT_SYMBOL_GPL(vp_modern_set_features);
443 
444 /*
445  * vp_modern_generation - get the device genreation
446  * @mdev: the modern virtio-pci device
447  *
448  * Returns the genreation read from device
449  */
450 u32 vp_modern_generation(struct virtio_pci_modern_device *mdev)
451 {
452 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
453 
454 	return vp_ioread8(&cfg->config_generation);
455 }
456 EXPORT_SYMBOL_GPL(vp_modern_generation);
457 
458 /*
459  * vp_modern_get_status - get the device status
460  * @mdev: the modern virtio-pci device
461  *
462  * Returns the status read from device
463  */
464 u8 vp_modern_get_status(struct virtio_pci_modern_device *mdev)
465 {
466 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
467 
468 	return vp_ioread8(&cfg->device_status);
469 }
470 EXPORT_SYMBOL_GPL(vp_modern_get_status);
471 
472 /*
473  * vp_modern_set_status - set status to device
474  * @mdev: the modern virtio-pci device
475  * @status: the status set to device
476  */
477 void vp_modern_set_status(struct virtio_pci_modern_device *mdev,
478 				 u8 status)
479 {
480 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
481 
482 	/*
483 	 * Per memory-barriers.txt, wmb() is not needed to guarantee
484 	 * that the cache coherent memory writes have completed
485 	 * before writing to the MMIO region.
486 	 */
487 	vp_iowrite8(status, &cfg->device_status);
488 }
489 EXPORT_SYMBOL_GPL(vp_modern_set_status);
490 
491 /*
492  * vp_modern_get_queue_reset - get the queue reset status
493  * @mdev: the modern virtio-pci device
494  * @index: queue index
495  */
496 int vp_modern_get_queue_reset(struct virtio_pci_modern_device *mdev, u16 index)
497 {
498 	struct virtio_pci_modern_common_cfg __iomem *cfg;
499 
500 	cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev->common;
501 
502 	vp_iowrite16(index, &cfg->cfg.queue_select);
503 	return vp_ioread16(&cfg->queue_reset);
504 }
505 EXPORT_SYMBOL_GPL(vp_modern_get_queue_reset);
506 
507 /*
508  * vp_modern_set_queue_reset - reset the queue
509  * @mdev: the modern virtio-pci device
510  * @index: queue index
511  */
512 void vp_modern_set_queue_reset(struct virtio_pci_modern_device *mdev, u16 index)
513 {
514 	struct virtio_pci_modern_common_cfg __iomem *cfg;
515 
516 	cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev->common;
517 
518 	vp_iowrite16(index, &cfg->cfg.queue_select);
519 	vp_iowrite16(1, &cfg->queue_reset);
520 
521 	while (vp_ioread16(&cfg->queue_reset))
522 		msleep(1);
523 
524 	while (vp_ioread16(&cfg->cfg.queue_enable))
525 		msleep(1);
526 }
527 EXPORT_SYMBOL_GPL(vp_modern_set_queue_reset);
528 
529 /*
530  * vp_modern_queue_vector - set the MSIX vector for a specific virtqueue
531  * @mdev: the modern virtio-pci device
532  * @index: queue index
533  * @vector: the config vector
534  *
535  * Returns the config vector read from the device
536  */
537 u16 vp_modern_queue_vector(struct virtio_pci_modern_device *mdev,
538 			   u16 index, u16 vector)
539 {
540 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
541 
542 	vp_iowrite16(index, &cfg->queue_select);
543 	vp_iowrite16(vector, &cfg->queue_msix_vector);
544 	/* Flush the write out to device */
545 	return vp_ioread16(&cfg->queue_msix_vector);
546 }
547 EXPORT_SYMBOL_GPL(vp_modern_queue_vector);
548 
549 /*
550  * vp_modern_config_vector - set the vector for config interrupt
551  * @mdev: the modern virtio-pci device
552  * @vector: the config vector
553  *
554  * Returns the config vector read from the device
555  */
556 u16 vp_modern_config_vector(struct virtio_pci_modern_device *mdev,
557 			    u16 vector)
558 {
559 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
560 
561 	/* Setup the vector used for configuration events */
562 	vp_iowrite16(vector, &cfg->msix_config);
563 	/* Verify we had enough resources to assign the vector */
564 	/* Will also flush the write out to device */
565 	return vp_ioread16(&cfg->msix_config);
566 }
567 EXPORT_SYMBOL_GPL(vp_modern_config_vector);
568 
569 /*
570  * vp_modern_queue_address - set the virtqueue address
571  * @mdev: the modern virtio-pci device
572  * @index: the queue index
573  * @desc_addr: address of the descriptor area
574  * @driver_addr: address of the driver area
575  * @device_addr: address of the device area
576  */
577 void vp_modern_queue_address(struct virtio_pci_modern_device *mdev,
578 			     u16 index, u64 desc_addr, u64 driver_addr,
579 			     u64 device_addr)
580 {
581 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
582 
583 	vp_iowrite16(index, &cfg->queue_select);
584 
585 	vp_iowrite64_twopart(desc_addr, &cfg->queue_desc_lo,
586 			     &cfg->queue_desc_hi);
587 	vp_iowrite64_twopart(driver_addr, &cfg->queue_avail_lo,
588 			     &cfg->queue_avail_hi);
589 	vp_iowrite64_twopart(device_addr, &cfg->queue_used_lo,
590 			     &cfg->queue_used_hi);
591 }
592 EXPORT_SYMBOL_GPL(vp_modern_queue_address);
593 
594 /*
595  * vp_modern_set_queue_enable - enable a virtqueue
596  * @mdev: the modern virtio-pci device
597  * @index: the queue index
598  * @enable: whether the virtqueue is enable or not
599  */
600 void vp_modern_set_queue_enable(struct virtio_pci_modern_device *mdev,
601 				u16 index, bool enable)
602 {
603 	vp_iowrite16(index, &mdev->common->queue_select);
604 	vp_iowrite16(enable, &mdev->common->queue_enable);
605 }
606 EXPORT_SYMBOL_GPL(vp_modern_set_queue_enable);
607 
608 /*
609  * vp_modern_get_queue_enable - enable a virtqueue
610  * @mdev: the modern virtio-pci device
611  * @index: the queue index
612  *
613  * Returns whether a virtqueue is enabled or not
614  */
615 bool vp_modern_get_queue_enable(struct virtio_pci_modern_device *mdev,
616 				u16 index)
617 {
618 	vp_iowrite16(index, &mdev->common->queue_select);
619 
620 	return vp_ioread16(&mdev->common->queue_enable);
621 }
622 EXPORT_SYMBOL_GPL(vp_modern_get_queue_enable);
623 
624 /*
625  * vp_modern_set_queue_size - set size for a virtqueue
626  * @mdev: the modern virtio-pci device
627  * @index: the queue index
628  * @size: the size of the virtqueue
629  */
630 void vp_modern_set_queue_size(struct virtio_pci_modern_device *mdev,
631 			      u16 index, u16 size)
632 {
633 	vp_iowrite16(index, &mdev->common->queue_select);
634 	vp_iowrite16(size, &mdev->common->queue_size);
635 
636 }
637 EXPORT_SYMBOL_GPL(vp_modern_set_queue_size);
638 
639 /*
640  * vp_modern_get_queue_size - get size for a virtqueue
641  * @mdev: the modern virtio-pci device
642  * @index: the queue index
643  *
644  * Returns the size of the virtqueue
645  */
646 u16 vp_modern_get_queue_size(struct virtio_pci_modern_device *mdev,
647 			     u16 index)
648 {
649 	vp_iowrite16(index, &mdev->common->queue_select);
650 
651 	return vp_ioread16(&mdev->common->queue_size);
652 
653 }
654 EXPORT_SYMBOL_GPL(vp_modern_get_queue_size);
655 
656 /*
657  * vp_modern_get_num_queues - get the number of virtqueues
658  * @mdev: the modern virtio-pci device
659  *
660  * Returns the number of virtqueues
661  */
662 u16 vp_modern_get_num_queues(struct virtio_pci_modern_device *mdev)
663 {
664 	return vp_ioread16(&mdev->common->num_queues);
665 }
666 EXPORT_SYMBOL_GPL(vp_modern_get_num_queues);
667 
668 /*
669  * vp_modern_get_queue_notify_off - get notification offset for a virtqueue
670  * @mdev: the modern virtio-pci device
671  * @index: the queue index
672  *
673  * Returns the notification offset for a virtqueue
674  */
675 static u16 vp_modern_get_queue_notify_off(struct virtio_pci_modern_device *mdev,
676 					  u16 index)
677 {
678 	vp_iowrite16(index, &mdev->common->queue_select);
679 
680 	return vp_ioread16(&mdev->common->queue_notify_off);
681 }
682 
683 /*
684  * vp_modern_map_vq_notify - map notification area for a
685  * specific virtqueue
686  * @mdev: the modern virtio-pci device
687  * @index: the queue index
688  * @pa: the pointer to the physical address of the nofity area
689  *
690  * Returns the address of the notification area
691  */
692 void __iomem *vp_modern_map_vq_notify(struct virtio_pci_modern_device *mdev,
693 				      u16 index, resource_size_t *pa)
694 {
695 	u16 off = vp_modern_get_queue_notify_off(mdev, index);
696 
697 	if (mdev->notify_base) {
698 		/* offset should not wrap */
699 		if ((u64)off * mdev->notify_offset_multiplier + 2
700 			> mdev->notify_len) {
701 			dev_warn(&mdev->pci_dev->dev,
702 				 "bad notification offset %u (x %u) "
703 				 "for queue %u > %zd",
704 				 off, mdev->notify_offset_multiplier,
705 				 index, mdev->notify_len);
706 			return NULL;
707 		}
708 		if (pa)
709 			*pa = mdev->notify_pa +
710 			      off * mdev->notify_offset_multiplier;
711 		return mdev->notify_base + off * mdev->notify_offset_multiplier;
712 	} else {
713 		return vp_modern_map_capability(mdev,
714 				       mdev->notify_map_cap, 2, 2,
715 				       off * mdev->notify_offset_multiplier, 2,
716 				       NULL, pa);
717 	}
718 }
719 EXPORT_SYMBOL_GPL(vp_modern_map_vq_notify);
720 
721 MODULE_VERSION("0.1");
722 MODULE_DESCRIPTION("Modern Virtio PCI Device");
723 MODULE_AUTHOR("Jason Wang <jasowang@redhat.com>");
724 MODULE_LICENSE("GPL");
725