xref: /linux/drivers/virtio/virtio_pci_modern_dev.c (revision 9e56ff53b4115875667760445b028357848b4748)
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 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_ADM_Q_IDX !=
211 		     offsetof(struct virtio_pci_modern_common_cfg, admin_queue_index));
212 	BUILD_BUG_ON(VIRTIO_PCI_COMMON_ADM_Q_NUM !=
213 		     offsetof(struct virtio_pci_modern_common_cfg, admin_queue_num));
214 }
215 
216 /*
217  * vp_modern_probe: probe the modern virtio pci device, note that the
218  * caller is required to enable PCI device before calling this function.
219  * @mdev: the modern virtio-pci device
220  *
221  * Return 0 on succeed otherwise fail
222  */
223 int vp_modern_probe(struct virtio_pci_modern_device *mdev)
224 {
225 	struct pci_dev *pci_dev = mdev->pci_dev;
226 	int err, common, isr, notify, device;
227 	u32 notify_length;
228 	u32 notify_offset;
229 	int devid;
230 
231 	check_offsets();
232 
233 	if (mdev->device_id_check) {
234 		devid = mdev->device_id_check(pci_dev);
235 		if (devid < 0)
236 			return devid;
237 		mdev->id.device = devid;
238 	} else {
239 		/* We only own devices >= 0x1000 and <= 0x107f: leave the rest. */
240 		if (pci_dev->device < 0x1000 || pci_dev->device > 0x107f)
241 			return -ENODEV;
242 
243 		if (pci_dev->device < 0x1040) {
244 			/* Transitional devices: use the PCI subsystem device id as
245 			 * virtio device id, same as legacy driver always did.
246 			 */
247 			mdev->id.device = pci_dev->subsystem_device;
248 		} else {
249 			/* Modern devices: simply use PCI device id, but start from 0x1040. */
250 			mdev->id.device = pci_dev->device - 0x1040;
251 		}
252 	}
253 	mdev->id.vendor = pci_dev->subsystem_vendor;
254 
255 	/* check for a common config: if not, use legacy mode (bar 0). */
256 	common = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG,
257 					    IORESOURCE_IO | IORESOURCE_MEM,
258 					    &mdev->modern_bars);
259 	if (!common) {
260 		dev_info(&pci_dev->dev,
261 			 "virtio_pci: leaving for legacy driver\n");
262 		return -ENODEV;
263 	}
264 
265 	/* If common is there, these should be too... */
266 	isr = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_ISR_CFG,
267 					 IORESOURCE_IO | IORESOURCE_MEM,
268 					 &mdev->modern_bars);
269 	notify = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG,
270 					    IORESOURCE_IO | IORESOURCE_MEM,
271 					    &mdev->modern_bars);
272 	if (!isr || !notify) {
273 		dev_err(&pci_dev->dev,
274 			"virtio_pci: missing capabilities %i/%i/%i\n",
275 			common, isr, notify);
276 		return -EINVAL;
277 	}
278 
279 	err = dma_set_mask_and_coherent(&pci_dev->dev,
280 					mdev->dma_mask ? : DMA_BIT_MASK(64));
281 	if (err)
282 		err = dma_set_mask_and_coherent(&pci_dev->dev,
283 						DMA_BIT_MASK(32));
284 	if (err)
285 		dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA.  Trying to continue, but this might not work.\n");
286 
287 	/* Device capability is only mandatory for devices that have
288 	 * device-specific configuration.
289 	 */
290 	device = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_DEVICE_CFG,
291 					    IORESOURCE_IO | IORESOURCE_MEM,
292 					    &mdev->modern_bars);
293 
294 	err = pci_request_selected_regions(pci_dev, mdev->modern_bars,
295 					   "virtio-pci-modern");
296 	if (err)
297 		return err;
298 
299 	err = -EINVAL;
300 	mdev->common = vp_modern_map_capability(mdev, common,
301 			      sizeof(struct virtio_pci_common_cfg), 4, 0,
302 			      offsetofend(struct virtio_pci_modern_common_cfg,
303 					  admin_queue_num),
304 			      &mdev->common_len, NULL);
305 	if (!mdev->common)
306 		goto err_map_common;
307 	mdev->isr = vp_modern_map_capability(mdev, isr, sizeof(u8), 1,
308 					     0, 1,
309 					     NULL, NULL);
310 	if (!mdev->isr)
311 		goto err_map_isr;
312 
313 	/* Read notify_off_multiplier from config space. */
314 	pci_read_config_dword(pci_dev,
315 			      notify + offsetof(struct virtio_pci_notify_cap,
316 						notify_off_multiplier),
317 			      &mdev->notify_offset_multiplier);
318 	/* Read notify length and offset from config space. */
319 	pci_read_config_dword(pci_dev,
320 			      notify + offsetof(struct virtio_pci_notify_cap,
321 						cap.length),
322 			      &notify_length);
323 
324 	pci_read_config_dword(pci_dev,
325 			      notify + offsetof(struct virtio_pci_notify_cap,
326 						cap.offset),
327 			      &notify_offset);
328 
329 	/* We don't know how many VQs we'll map, ahead of the time.
330 	 * If notify length is small, map it all now.
331 	 * Otherwise, map each VQ individually later.
332 	 */
333 	if ((u64)notify_length + (notify_offset % PAGE_SIZE) <= PAGE_SIZE) {
334 		mdev->notify_base = vp_modern_map_capability(mdev, notify,
335 							     2, 2,
336 							     0, notify_length,
337 							     &mdev->notify_len,
338 							     &mdev->notify_pa);
339 		if (!mdev->notify_base)
340 			goto err_map_notify;
341 	} else {
342 		mdev->notify_map_cap = notify;
343 	}
344 
345 	/* Again, we don't know how much we should map, but PAGE_SIZE
346 	 * is more than enough for all existing devices.
347 	 */
348 	if (device) {
349 		mdev->device = vp_modern_map_capability(mdev, device, 0, 4,
350 							0, PAGE_SIZE,
351 							&mdev->device_len,
352 							NULL);
353 		if (!mdev->device)
354 			goto err_map_device;
355 	}
356 
357 	return 0;
358 
359 err_map_device:
360 	if (mdev->notify_base)
361 		pci_iounmap(pci_dev, mdev->notify_base);
362 err_map_notify:
363 	pci_iounmap(pci_dev, mdev->isr);
364 err_map_isr:
365 	pci_iounmap(pci_dev, mdev->common);
366 err_map_common:
367 	pci_release_selected_regions(pci_dev, mdev->modern_bars);
368 	return err;
369 }
370 EXPORT_SYMBOL_GPL(vp_modern_probe);
371 
372 /*
373  * vp_modern_remove: remove and cleanup the modern virtio pci device
374  * @mdev: the modern virtio-pci device
375  */
376 void vp_modern_remove(struct virtio_pci_modern_device *mdev)
377 {
378 	struct pci_dev *pci_dev = mdev->pci_dev;
379 
380 	if (mdev->device)
381 		pci_iounmap(pci_dev, mdev->device);
382 	if (mdev->notify_base)
383 		pci_iounmap(pci_dev, mdev->notify_base);
384 	pci_iounmap(pci_dev, mdev->isr);
385 	pci_iounmap(pci_dev, mdev->common);
386 	pci_release_selected_regions(pci_dev, mdev->modern_bars);
387 }
388 EXPORT_SYMBOL_GPL(vp_modern_remove);
389 
390 /*
391  * vp_modern_get_features - get features from device
392  * @mdev: the modern virtio-pci device
393  *
394  * Returns the features read from the device
395  */
396 u64 vp_modern_get_features(struct virtio_pci_modern_device *mdev)
397 {
398 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
399 
400 	u64 features;
401 
402 	vp_iowrite32(0, &cfg->device_feature_select);
403 	features = vp_ioread32(&cfg->device_feature);
404 	vp_iowrite32(1, &cfg->device_feature_select);
405 	features |= ((u64)vp_ioread32(&cfg->device_feature) << 32);
406 
407 	return features;
408 }
409 EXPORT_SYMBOL_GPL(vp_modern_get_features);
410 
411 /*
412  * vp_modern_get_driver_features - get driver features from device
413  * @mdev: the modern virtio-pci device
414  *
415  * Returns the driver features read from the device
416  */
417 u64 vp_modern_get_driver_features(struct virtio_pci_modern_device *mdev)
418 {
419 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
420 
421 	u64 features;
422 
423 	vp_iowrite32(0, &cfg->guest_feature_select);
424 	features = vp_ioread32(&cfg->guest_feature);
425 	vp_iowrite32(1, &cfg->guest_feature_select);
426 	features |= ((u64)vp_ioread32(&cfg->guest_feature) << 32);
427 
428 	return features;
429 }
430 EXPORT_SYMBOL_GPL(vp_modern_get_driver_features);
431 
432 /*
433  * vp_modern_set_features - set features to device
434  * @mdev: the modern virtio-pci device
435  * @features: the features set to device
436  */
437 void vp_modern_set_features(struct virtio_pci_modern_device *mdev,
438 			    u64 features)
439 {
440 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
441 
442 	vp_iowrite32(0, &cfg->guest_feature_select);
443 	vp_iowrite32((u32)features, &cfg->guest_feature);
444 	vp_iowrite32(1, &cfg->guest_feature_select);
445 	vp_iowrite32(features >> 32, &cfg->guest_feature);
446 }
447 EXPORT_SYMBOL_GPL(vp_modern_set_features);
448 
449 /*
450  * vp_modern_generation - get the device genreation
451  * @mdev: the modern virtio-pci device
452  *
453  * Returns the genreation read from device
454  */
455 u32 vp_modern_generation(struct virtio_pci_modern_device *mdev)
456 {
457 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
458 
459 	return vp_ioread8(&cfg->config_generation);
460 }
461 EXPORT_SYMBOL_GPL(vp_modern_generation);
462 
463 /*
464  * vp_modern_get_status - get the device status
465  * @mdev: the modern virtio-pci device
466  *
467  * Returns the status read from device
468  */
469 u8 vp_modern_get_status(struct virtio_pci_modern_device *mdev)
470 {
471 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
472 
473 	return vp_ioread8(&cfg->device_status);
474 }
475 EXPORT_SYMBOL_GPL(vp_modern_get_status);
476 
477 /*
478  * vp_modern_set_status - set status to device
479  * @mdev: the modern virtio-pci device
480  * @status: the status set to device
481  */
482 void vp_modern_set_status(struct virtio_pci_modern_device *mdev,
483 				 u8 status)
484 {
485 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
486 
487 	/*
488 	 * Per memory-barriers.txt, wmb() is not needed to guarantee
489 	 * that the cache coherent memory writes have completed
490 	 * before writing to the MMIO region.
491 	 */
492 	vp_iowrite8(status, &cfg->device_status);
493 }
494 EXPORT_SYMBOL_GPL(vp_modern_set_status);
495 
496 /*
497  * vp_modern_get_queue_reset - get the queue reset status
498  * @mdev: the modern virtio-pci device
499  * @index: queue index
500  */
501 int vp_modern_get_queue_reset(struct virtio_pci_modern_device *mdev, u16 index)
502 {
503 	struct virtio_pci_modern_common_cfg __iomem *cfg;
504 
505 	cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev->common;
506 
507 	vp_iowrite16(index, &cfg->cfg.queue_select);
508 	return vp_ioread16(&cfg->queue_reset);
509 }
510 EXPORT_SYMBOL_GPL(vp_modern_get_queue_reset);
511 
512 /*
513  * vp_modern_set_queue_reset - reset the queue
514  * @mdev: the modern virtio-pci device
515  * @index: queue index
516  */
517 void vp_modern_set_queue_reset(struct virtio_pci_modern_device *mdev, u16 index)
518 {
519 	struct virtio_pci_modern_common_cfg __iomem *cfg;
520 
521 	cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev->common;
522 
523 	vp_iowrite16(index, &cfg->cfg.queue_select);
524 	vp_iowrite16(1, &cfg->queue_reset);
525 
526 	while (vp_ioread16(&cfg->queue_reset))
527 		msleep(1);
528 
529 	while (vp_ioread16(&cfg->cfg.queue_enable))
530 		msleep(1);
531 }
532 EXPORT_SYMBOL_GPL(vp_modern_set_queue_reset);
533 
534 /*
535  * vp_modern_queue_vector - set the MSIX vector for a specific virtqueue
536  * @mdev: the modern virtio-pci device
537  * @index: queue index
538  * @vector: the config vector
539  *
540  * Returns the config vector read from the device
541  */
542 u16 vp_modern_queue_vector(struct virtio_pci_modern_device *mdev,
543 			   u16 index, u16 vector)
544 {
545 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
546 
547 	vp_iowrite16(index, &cfg->queue_select);
548 	vp_iowrite16(vector, &cfg->queue_msix_vector);
549 	/* Flush the write out to device */
550 	return vp_ioread16(&cfg->queue_msix_vector);
551 }
552 EXPORT_SYMBOL_GPL(vp_modern_queue_vector);
553 
554 /*
555  * vp_modern_config_vector - set the vector for config interrupt
556  * @mdev: the modern virtio-pci device
557  * @vector: the config vector
558  *
559  * Returns the config vector read from the device
560  */
561 u16 vp_modern_config_vector(struct virtio_pci_modern_device *mdev,
562 			    u16 vector)
563 {
564 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
565 
566 	/* Setup the vector used for configuration events */
567 	vp_iowrite16(vector, &cfg->msix_config);
568 	/* Verify we had enough resources to assign the vector */
569 	/* Will also flush the write out to device */
570 	return vp_ioread16(&cfg->msix_config);
571 }
572 EXPORT_SYMBOL_GPL(vp_modern_config_vector);
573 
574 /*
575  * vp_modern_queue_address - set the virtqueue address
576  * @mdev: the modern virtio-pci device
577  * @index: the queue index
578  * @desc_addr: address of the descriptor area
579  * @driver_addr: address of the driver area
580  * @device_addr: address of the device area
581  */
582 void vp_modern_queue_address(struct virtio_pci_modern_device *mdev,
583 			     u16 index, u64 desc_addr, u64 driver_addr,
584 			     u64 device_addr)
585 {
586 	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
587 
588 	vp_iowrite16(index, &cfg->queue_select);
589 
590 	vp_iowrite64_twopart(desc_addr, &cfg->queue_desc_lo,
591 			     &cfg->queue_desc_hi);
592 	vp_iowrite64_twopart(driver_addr, &cfg->queue_avail_lo,
593 			     &cfg->queue_avail_hi);
594 	vp_iowrite64_twopart(device_addr, &cfg->queue_used_lo,
595 			     &cfg->queue_used_hi);
596 }
597 EXPORT_SYMBOL_GPL(vp_modern_queue_address);
598 
599 /*
600  * vp_modern_set_queue_enable - enable a virtqueue
601  * @mdev: the modern virtio-pci device
602  * @index: the queue index
603  * @enable: whether the virtqueue is enable or not
604  */
605 void vp_modern_set_queue_enable(struct virtio_pci_modern_device *mdev,
606 				u16 index, bool enable)
607 {
608 	vp_iowrite16(index, &mdev->common->queue_select);
609 	vp_iowrite16(enable, &mdev->common->queue_enable);
610 }
611 EXPORT_SYMBOL_GPL(vp_modern_set_queue_enable);
612 
613 /*
614  * vp_modern_get_queue_enable - enable a virtqueue
615  * @mdev: the modern virtio-pci device
616  * @index: the queue index
617  *
618  * Returns whether a virtqueue is enabled or not
619  */
620 bool vp_modern_get_queue_enable(struct virtio_pci_modern_device *mdev,
621 				u16 index)
622 {
623 	vp_iowrite16(index, &mdev->common->queue_select);
624 
625 	return vp_ioread16(&mdev->common->queue_enable);
626 }
627 EXPORT_SYMBOL_GPL(vp_modern_get_queue_enable);
628 
629 /*
630  * vp_modern_set_queue_size - set size for a virtqueue
631  * @mdev: the modern virtio-pci device
632  * @index: the queue index
633  * @size: the size of the virtqueue
634  */
635 void vp_modern_set_queue_size(struct virtio_pci_modern_device *mdev,
636 			      u16 index, u16 size)
637 {
638 	vp_iowrite16(index, &mdev->common->queue_select);
639 	vp_iowrite16(size, &mdev->common->queue_size);
640 
641 }
642 EXPORT_SYMBOL_GPL(vp_modern_set_queue_size);
643 
644 /*
645  * vp_modern_get_queue_size - get size for a virtqueue
646  * @mdev: the modern virtio-pci device
647  * @index: the queue index
648  *
649  * Returns the size of the virtqueue
650  */
651 u16 vp_modern_get_queue_size(struct virtio_pci_modern_device *mdev,
652 			     u16 index)
653 {
654 	vp_iowrite16(index, &mdev->common->queue_select);
655 
656 	return vp_ioread16(&mdev->common->queue_size);
657 
658 }
659 EXPORT_SYMBOL_GPL(vp_modern_get_queue_size);
660 
661 /*
662  * vp_modern_get_num_queues - get the number of virtqueues
663  * @mdev: the modern virtio-pci device
664  *
665  * Returns the number of virtqueues
666  */
667 u16 vp_modern_get_num_queues(struct virtio_pci_modern_device *mdev)
668 {
669 	return vp_ioread16(&mdev->common->num_queues);
670 }
671 EXPORT_SYMBOL_GPL(vp_modern_get_num_queues);
672 
673 /*
674  * vp_modern_get_queue_notify_off - get notification offset for a virtqueue
675  * @mdev: the modern virtio-pci device
676  * @index: the queue index
677  *
678  * Returns the notification offset for a virtqueue
679  */
680 static u16 vp_modern_get_queue_notify_off(struct virtio_pci_modern_device *mdev,
681 					  u16 index)
682 {
683 	vp_iowrite16(index, &mdev->common->queue_select);
684 
685 	return vp_ioread16(&mdev->common->queue_notify_off);
686 }
687 
688 /*
689  * vp_modern_map_vq_notify - map notification area for a
690  * specific virtqueue
691  * @mdev: the modern virtio-pci device
692  * @index: the queue index
693  * @pa: the pointer to the physical address of the nofity area
694  *
695  * Returns the address of the notification area
696  */
697 void __iomem *vp_modern_map_vq_notify(struct virtio_pci_modern_device *mdev,
698 				      u16 index, resource_size_t *pa)
699 {
700 	u16 off = vp_modern_get_queue_notify_off(mdev, index);
701 
702 	if (mdev->notify_base) {
703 		/* offset should not wrap */
704 		if ((u64)off * mdev->notify_offset_multiplier + 2
705 			> mdev->notify_len) {
706 			dev_warn(&mdev->pci_dev->dev,
707 				 "bad notification offset %u (x %u) "
708 				 "for queue %u > %zd",
709 				 off, mdev->notify_offset_multiplier,
710 				 index, mdev->notify_len);
711 			return NULL;
712 		}
713 		if (pa)
714 			*pa = mdev->notify_pa +
715 			      off * mdev->notify_offset_multiplier;
716 		return mdev->notify_base + off * mdev->notify_offset_multiplier;
717 	} else {
718 		return vp_modern_map_capability(mdev,
719 				       mdev->notify_map_cap, 2, 2,
720 				       off * mdev->notify_offset_multiplier, 2,
721 				       NULL, pa);
722 	}
723 }
724 EXPORT_SYMBOL_GPL(vp_modern_map_vq_notify);
725 
726 u16 vp_modern_avq_num(struct virtio_pci_modern_device *mdev)
727 {
728 	struct virtio_pci_modern_common_cfg __iomem *cfg;
729 
730 	cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev->common;
731 	return vp_ioread16(&cfg->admin_queue_num);
732 }
733 EXPORT_SYMBOL_GPL(vp_modern_avq_num);
734 
735 u16 vp_modern_avq_index(struct virtio_pci_modern_device *mdev)
736 {
737 	struct virtio_pci_modern_common_cfg __iomem *cfg;
738 
739 	cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev->common;
740 	return vp_ioread16(&cfg->admin_queue_index);
741 }
742 EXPORT_SYMBOL_GPL(vp_modern_avq_index);
743 
744 MODULE_VERSION("0.1");
745 MODULE_DESCRIPTION("Modern Virtio PCI Device");
746 MODULE_AUTHOR("Jason Wang <jasowang@redhat.com>");
747 MODULE_LICENSE("GPL");
748