2 * Intel MIC Platform Software Stack (MPSS)
4 * Copyright(c) 2016 Intel Corporation.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License, version 2, as
8 * published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * The full GNU General Public License is included in this distribution in
16 * the file called "COPYING".
20 * virtio for kvm on s390
22 * Copyright IBM Corp. 2008
24 * This program is free software; you can redistribute it and/or modify
25 * it under the terms of the GNU General Public License (version 2 only)
26 * as published by the Free Software Foundation.
28 * Author(s): Christian Borntraeger <borntraeger@de.ibm.com>
30 * Intel Virtio Over PCIe (VOP) driver.
33 #include <linux/delay.h>
34 #include <linux/module.h>
35 #include <linux/sched.h>
36 #include <linux/dma-mapping.h>
40 #define VOP_MAX_VRINGS 4
43 * _vop_vdev - Allocated per virtio device instance injected by the peer.
45 * @vdev: Virtio device
46 * @desc: Virtio device page descriptor
47 * @dc: Virtio device control
48 * @vpdev: VOP device which is the parent for this virtio device
49 * @vr: Buffer for accessing the VRING
50 * @used: Buffer for used
51 * @used_size: Size of the used buffer
52 * @reset_done: Track whether VOP reset is complete
53 * @virtio_cookie: Cookie returned upon requesting a interrupt
54 * @c2h_vdev_db: The doorbell used by the guest to interrupt the host
55 * @h2c_vdev_db: The doorbell used by the host to interrupt the guest
56 * @dnode: The destination node
59 struct virtio_device vdev;
60 struct mic_device_desc __iomem *desc;
61 struct mic_device_ctrl __iomem *dc;
62 struct vop_device *vpdev;
63 void __iomem *vr[VOP_MAX_VRINGS];
64 dma_addr_t used[VOP_MAX_VRINGS];
65 int used_size[VOP_MAX_VRINGS];
66 struct completion reset_done;
67 struct mic_irq *virtio_cookie;
73 #define to_vopvdev(vd) container_of(vd, struct _vop_vdev, vdev)
75 #define _vop_aligned_desc_size(d) __mic_align(_vop_desc_size(d), 8)
77 /* Helper API to obtain the parent of the virtio device */
78 static inline struct device *_vop_dev(struct _vop_vdev *vdev)
80 return vdev->vdev.dev.parent;
83 static inline unsigned _vop_desc_size(struct mic_device_desc __iomem *desc)
86 + ioread8(&desc->num_vq) * sizeof(struct mic_vqconfig)
87 + ioread8(&desc->feature_len) * 2
88 + ioread8(&desc->config_len);
91 static inline struct mic_vqconfig __iomem *
92 _vop_vq_config(struct mic_device_desc __iomem *desc)
94 return (struct mic_vqconfig __iomem *)(desc + 1);
97 static inline u8 __iomem *
98 _vop_vq_features(struct mic_device_desc __iomem *desc)
100 return (u8 __iomem *)(_vop_vq_config(desc) + ioread8(&desc->num_vq));
103 static inline u8 __iomem *
104 _vop_vq_configspace(struct mic_device_desc __iomem *desc)
106 return _vop_vq_features(desc) + ioread8(&desc->feature_len) * 2;
109 static inline unsigned
110 _vop_total_desc_size(struct mic_device_desc __iomem *desc)
112 return _vop_aligned_desc_size(desc) + sizeof(struct mic_device_ctrl);
115 /* This gets the device's feature bits. */
116 static u64 vop_get_features(struct virtio_device *vdev)
118 unsigned int i, bits;
120 struct mic_device_desc __iomem *desc = to_vopvdev(vdev)->desc;
121 u8 __iomem *in_features = _vop_vq_features(desc);
122 int feature_len = ioread8(&desc->feature_len);
124 bits = min_t(unsigned, feature_len, sizeof(vdev->features)) * 8;
125 for (i = 0; i < bits; i++)
126 if (ioread8(&in_features[i / 8]) & (BIT(i % 8)))
132 static void vop_transport_features(struct virtio_device *vdev)
135 * Packed ring isn't enabled on virtio_vop for now,
136 * because virtio_vop uses vring_new_virtqueue() which
137 * creates virtio rings on preallocated memory.
139 __virtio_clear_bit(vdev, VIRTIO_F_RING_PACKED);
142 static int vop_finalize_features(struct virtio_device *vdev)
144 unsigned int i, bits;
145 struct mic_device_desc __iomem *desc = to_vopvdev(vdev)->desc;
146 u8 feature_len = ioread8(&desc->feature_len);
147 /* Second half of bitmap is features we accept. */
148 u8 __iomem *out_features =
149 _vop_vq_features(desc) + feature_len;
151 /* Give virtio_ring a chance to accept features. */
152 vring_transport_features(vdev);
154 /* Give virtio_vop a chance to accept features. */
155 vop_transport_features(vdev);
157 memset_io(out_features, 0, feature_len);
158 bits = min_t(unsigned, feature_len,
159 sizeof(vdev->features)) * 8;
160 for (i = 0; i < bits; i++) {
161 if (__virtio_test_bit(vdev, i))
162 iowrite8(ioread8(&out_features[i / 8]) | (1 << (i % 8)),
163 &out_features[i / 8]);
169 * Reading and writing elements in config space
171 static void vop_get(struct virtio_device *vdev, unsigned int offset,
172 void *buf, unsigned len)
174 struct mic_device_desc __iomem *desc = to_vopvdev(vdev)->desc;
176 if (offset + len > ioread8(&desc->config_len))
178 memcpy_fromio(buf, _vop_vq_configspace(desc) + offset, len);
181 static void vop_set(struct virtio_device *vdev, unsigned int offset,
182 const void *buf, unsigned len)
184 struct mic_device_desc __iomem *desc = to_vopvdev(vdev)->desc;
186 if (offset + len > ioread8(&desc->config_len))
188 memcpy_toio(_vop_vq_configspace(desc) + offset, buf, len);
192 * The operations to get and set the status word just access the status
193 * field of the device descriptor. set_status also interrupts the host
194 * to tell about status changes.
196 static u8 vop_get_status(struct virtio_device *vdev)
198 return ioread8(&to_vopvdev(vdev)->desc->status);
201 static void vop_set_status(struct virtio_device *dev, u8 status)
203 struct _vop_vdev *vdev = to_vopvdev(dev);
204 struct vop_device *vpdev = vdev->vpdev;
208 iowrite8(status, &vdev->desc->status);
209 vpdev->hw_ops->send_intr(vpdev, vdev->c2h_vdev_db);
212 /* Inform host on a virtio device reset and wait for ack from host */
213 static void vop_reset_inform_host(struct virtio_device *dev)
215 struct _vop_vdev *vdev = to_vopvdev(dev);
216 struct mic_device_ctrl __iomem *dc = vdev->dc;
217 struct vop_device *vpdev = vdev->vpdev;
220 iowrite8(0, &dc->host_ack);
221 iowrite8(1, &dc->vdev_reset);
222 vpdev->hw_ops->send_intr(vpdev, vdev->c2h_vdev_db);
224 /* Wait till host completes all card accesses and acks the reset */
225 for (retry = 100; retry--;) {
226 if (ioread8(&dc->host_ack))
231 dev_dbg(_vop_dev(vdev), "%s: retry: %d\n", __func__, retry);
233 /* Reset status to 0 in case we timed out */
234 iowrite8(0, &vdev->desc->status);
237 static void vop_reset(struct virtio_device *dev)
239 struct _vop_vdev *vdev = to_vopvdev(dev);
241 dev_dbg(_vop_dev(vdev), "%s: virtio id %d\n",
242 __func__, dev->id.device);
244 vop_reset_inform_host(dev);
245 complete_all(&vdev->reset_done);
249 * The virtio_ring code calls this API when it wants to notify the Host.
251 static bool vop_notify(struct virtqueue *vq)
253 struct _vop_vdev *vdev = vq->priv;
254 struct vop_device *vpdev = vdev->vpdev;
256 vpdev->hw_ops->send_intr(vpdev, vdev->c2h_vdev_db);
260 static void vop_del_vq(struct virtqueue *vq, int n)
262 struct _vop_vdev *vdev = to_vopvdev(vq->vdev);
263 struct vring *vr = (struct vring *)(vq + 1);
264 struct vop_device *vpdev = vdev->vpdev;
266 dma_unmap_single(&vpdev->dev, vdev->used[n],
267 vdev->used_size[n], DMA_BIDIRECTIONAL);
268 free_pages((unsigned long)vr->used, get_order(vdev->used_size[n]));
269 vring_del_virtqueue(vq);
270 vpdev->hw_ops->iounmap(vpdev, vdev->vr[n]);
274 static void vop_del_vqs(struct virtio_device *dev)
276 struct _vop_vdev *vdev = to_vopvdev(dev);
277 struct virtqueue *vq, *n;
280 dev_dbg(_vop_dev(vdev), "%s\n", __func__);
282 list_for_each_entry_safe(vq, n, &dev->vqs, list)
283 vop_del_vq(vq, idx++);
287 * This routine will assign vring's allocated in host/io memory. Code in
288 * virtio_ring.c however continues to access this io memory as if it were local
289 * memory without io accessors.
291 static struct virtqueue *vop_find_vq(struct virtio_device *dev,
293 void (*callback)(struct virtqueue *vq),
294 const char *name, bool ctx)
296 struct _vop_vdev *vdev = to_vopvdev(dev);
297 struct vop_device *vpdev = vdev->vpdev;
298 struct mic_vqconfig __iomem *vqconfig;
299 struct mic_vqconfig config;
300 struct virtqueue *vq;
302 struct _mic_vring_info __iomem *info;
304 int vr_size, _vr_size, err, magic;
306 u8 type = ioread8(&vdev->desc->type);
308 if (index >= ioread8(&vdev->desc->num_vq))
309 return ERR_PTR(-ENOENT);
312 return ERR_PTR(-ENOENT);
314 /* First assign the vring's allocated in host memory */
315 vqconfig = _vop_vq_config(vdev->desc) + index;
316 memcpy_fromio(&config, vqconfig, sizeof(config));
317 _vr_size = vring_size(le16_to_cpu(config.num), MIC_VIRTIO_RING_ALIGN);
318 vr_size = PAGE_ALIGN(_vr_size + sizeof(struct _mic_vring_info));
319 va = vpdev->hw_ops->ioremap(vpdev, le64_to_cpu(config.address),
322 return ERR_PTR(-ENOMEM);
323 vdev->vr[index] = va;
324 memset_io(va, 0x0, _vr_size);
325 vq = vring_new_virtqueue(
327 le16_to_cpu(config.num), MIC_VIRTIO_RING_ALIGN,
331 (void __force *)va, vop_notify, callback, name);
336 info = va + _vr_size;
337 magic = ioread32(&info->magic);
339 if (WARN(magic != MIC_MAGIC + type + index, "magic mismatch")) {
344 /* Allocate and reassign used ring now */
345 vdev->used_size[index] = PAGE_ALIGN(sizeof(__u16) * 3 +
346 sizeof(struct vring_used_elem) *
347 le16_to_cpu(config.num));
348 used = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
349 get_order(vdev->used_size[index]));
352 dev_err(_vop_dev(vdev), "%s %d err %d\n",
353 __func__, __LINE__, err);
356 vdev->used[index] = dma_map_single(&vpdev->dev, used,
357 vdev->used_size[index],
359 if (dma_mapping_error(&vpdev->dev, vdev->used[index])) {
361 dev_err(_vop_dev(vdev), "%s %d err %d\n",
362 __func__, __LINE__, err);
365 writeq(vdev->used[index], &vqconfig->used_address);
367 * To reassign the used ring here we are directly accessing
368 * struct vring_virtqueue which is a private data structure
369 * in virtio_ring.c. At the minimum, a BUILD_BUG_ON() in
370 * vring_new_virtqueue() would ensure that
371 * (&vq->vring == (struct vring *) (&vq->vq + 1));
373 vr = (struct vring *)(vq + 1);
379 free_pages((unsigned long)used,
380 get_order(vdev->used_size[index]));
382 vring_del_virtqueue(vq);
384 vpdev->hw_ops->iounmap(vpdev, vdev->vr[index]);
388 static int vop_find_vqs(struct virtio_device *dev, unsigned nvqs,
389 struct virtqueue *vqs[],
390 vq_callback_t *callbacks[],
391 const char * const names[], const bool *ctx,
392 struct irq_affinity *desc)
394 struct _vop_vdev *vdev = to_vopvdev(dev);
395 struct vop_device *vpdev = vdev->vpdev;
396 struct mic_device_ctrl __iomem *dc = vdev->dc;
397 int i, err, retry, queue_idx = 0;
399 /* We must have this many virtqueues. */
400 if (nvqs > ioread8(&vdev->desc->num_vq))
403 for (i = 0; i < nvqs; ++i) {
409 dev_dbg(_vop_dev(vdev), "%s: %d: %s\n",
410 __func__, i, names[i]);
411 vqs[i] = vop_find_vq(dev, queue_idx++, callbacks[i], names[i],
412 ctx ? ctx[i] : false);
413 if (IS_ERR(vqs[i])) {
414 err = PTR_ERR(vqs[i]);
419 iowrite8(1, &dc->used_address_updated);
421 * Send an interrupt to the host to inform it that used
422 * rings have been re-assigned.
424 vpdev->hw_ops->send_intr(vpdev, vdev->c2h_vdev_db);
425 for (retry = 100; --retry;) {
426 if (!ioread8(&dc->used_address_updated))
431 dev_dbg(_vop_dev(vdev), "%s: retry: %d\n", __func__, retry);
444 * The config ops structure as defined by virtio config
446 static struct virtio_config_ops vop_vq_config_ops = {
447 .get_features = vop_get_features,
448 .finalize_features = vop_finalize_features,
451 .get_status = vop_get_status,
452 .set_status = vop_set_status,
454 .find_vqs = vop_find_vqs,
455 .del_vqs = vop_del_vqs,
458 static irqreturn_t vop_virtio_intr_handler(int irq, void *data)
460 struct _vop_vdev *vdev = data;
461 struct vop_device *vpdev = vdev->vpdev;
462 struct virtqueue *vq;
464 vpdev->hw_ops->ack_interrupt(vpdev, vdev->h2c_vdev_db);
465 list_for_each_entry(vq, &vdev->vdev.vqs, list)
466 vring_interrupt(0, vq);
471 static void vop_virtio_release_dev(struct device *_d)
473 struct virtio_device *vdev =
474 container_of(_d, struct virtio_device, dev);
475 struct _vop_vdev *vop_vdev =
476 container_of(vdev, struct _vop_vdev, vdev);
482 * adds a new device and register it with virtio
483 * appropriate drivers are loaded by the device model
485 static int _vop_add_device(struct mic_device_desc __iomem *d,
486 unsigned int offset, struct vop_device *vpdev,
489 struct _vop_vdev *vdev, *reg_dev = NULL;
491 u8 type = ioread8(&d->type);
493 vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
498 vdev->vdev.dev.parent = &vpdev->dev;
499 vdev->vdev.dev.release = vop_virtio_release_dev;
500 vdev->vdev.id.device = type;
501 vdev->vdev.config = &vop_vq_config_ops;
503 vdev->dc = (void __iomem *)d + _vop_aligned_desc_size(d);
505 vdev->vdev.priv = (void *)(u64)dnode;
506 init_completion(&vdev->reset_done);
508 vdev->h2c_vdev_db = vpdev->hw_ops->next_db(vpdev);
509 vdev->virtio_cookie = vpdev->hw_ops->request_irq(vpdev,
510 vop_virtio_intr_handler, "virtio intr",
511 vdev, vdev->h2c_vdev_db);
512 if (IS_ERR(vdev->virtio_cookie)) {
513 ret = PTR_ERR(vdev->virtio_cookie);
516 iowrite8((u8)vdev->h2c_vdev_db, &vdev->dc->h2c_vdev_db);
517 vdev->c2h_vdev_db = ioread8(&vdev->dc->c2h_vdev_db);
519 ret = register_virtio_device(&vdev->vdev);
522 dev_err(_vop_dev(vdev),
523 "Failed to register vop device %u type %u\n",
527 writeq((u64)vdev, &vdev->dc->vdev);
528 dev_dbg(_vop_dev(vdev), "%s: registered vop device %u type %u vdev %p\n",
529 __func__, offset, type, vdev);
534 vpdev->hw_ops->free_irq(vpdev, vdev->virtio_cookie, vdev);
537 put_device(&vdev->vdev.dev);
544 * match for a vop device with a specific desc pointer
546 static int vop_match_desc(struct device *dev, void *data)
548 struct virtio_device *_dev = dev_to_virtio(dev);
549 struct _vop_vdev *vdev = to_vopvdev(_dev);
551 return vdev->desc == (void __iomem *)data;
554 static void _vop_handle_config_change(struct mic_device_desc __iomem *d,
556 struct vop_device *vpdev)
558 struct mic_device_ctrl __iomem *dc
559 = (void __iomem *)d + _vop_aligned_desc_size(d);
560 struct _vop_vdev *vdev = (struct _vop_vdev *)readq(&dc->vdev);
562 if (ioread8(&dc->config_change) != MIC_VIRTIO_PARAM_CONFIG_CHANGED)
565 dev_dbg(&vpdev->dev, "%s %d\n", __func__, __LINE__);
566 virtio_config_changed(&vdev->vdev);
567 iowrite8(1, &dc->guest_ack);
571 * removes a virtio device if a hot remove event has been
572 * requested by the host.
574 static int _vop_remove_device(struct mic_device_desc __iomem *d,
575 unsigned int offset, struct vop_device *vpdev)
577 struct mic_device_ctrl __iomem *dc
578 = (void __iomem *)d + _vop_aligned_desc_size(d);
579 struct _vop_vdev *vdev = (struct _vop_vdev *)readq(&dc->vdev);
583 if (ioread8(&dc->config_change) == MIC_VIRTIO_PARAM_DEV_REMOVE) {
585 "%s %d config_change %d type %d vdev %p\n",
587 ioread8(&dc->config_change), ioread8(&d->type), vdev);
588 status = ioread8(&d->status);
589 reinit_completion(&vdev->reset_done);
590 unregister_virtio_device(&vdev->vdev);
591 vpdev->hw_ops->free_irq(vpdev, vdev->virtio_cookie, vdev);
592 iowrite8(-1, &dc->h2c_vdev_db);
593 if (status & VIRTIO_CONFIG_S_DRIVER_OK)
594 wait_for_completion(&vdev->reset_done);
595 put_device(&vdev->vdev.dev);
596 iowrite8(1, &dc->guest_ack);
597 dev_dbg(&vpdev->dev, "%s %d guest_ack %d\n",
598 __func__, __LINE__, ioread8(&dc->guest_ack));
599 iowrite8(-1, &d->type);
605 #define REMOVE_DEVICES true
607 static void _vop_scan_devices(void __iomem *dp, struct vop_device *vpdev,
608 bool remove, int dnode)
612 struct mic_device_desc __iomem *d;
613 struct mic_device_ctrl __iomem *dc;
617 for (i = sizeof(struct mic_bootparam);
618 i < MIC_DP_SIZE; i += _vop_total_desc_size(d)) {
620 dc = (void __iomem *)d + _vop_aligned_desc_size(d);
622 * This read barrier is paired with the corresponding write
623 * barrier on the host which is inserted before adding or
624 * removing a virtio device descriptor, by updating the type.
627 type = ioread8(&d->type);
636 /* device already exists */
637 dev = device_find_child(&vpdev->dev, (void __force *)d,
641 iowrite8(MIC_VIRTIO_PARAM_DEV_REMOVE,
644 _vop_handle_config_change(d, i, vpdev);
645 ret = _vop_remove_device(d, i, vpdev);
647 iowrite8(0, &dc->config_change);
648 iowrite8(0, &dc->guest_ack);
654 dev_dbg(&vpdev->dev, "%s %d Adding new virtio device %p\n",
655 __func__, __LINE__, d);
657 _vop_add_device(d, i, vpdev, dnode);
661 static void vop_scan_devices(struct vop_info *vi,
662 struct vop_device *vpdev, bool remove)
664 void __iomem *dp = vpdev->hw_ops->get_remote_dp(vpdev);
668 mutex_lock(&vi->vop_mutex);
669 _vop_scan_devices(dp, vpdev, remove, vpdev->dnode);
670 mutex_unlock(&vi->vop_mutex);
674 * vop_hotplug_device tries to find changes in the device page.
676 static void vop_hotplug_devices(struct work_struct *work)
678 struct vop_info *vi = container_of(work, struct vop_info,
681 vop_scan_devices(vi, vi->vpdev, !REMOVE_DEVICES);
685 * Interrupt handler for hot plug/config changes etc.
687 static irqreturn_t vop_extint_handler(int irq, void *data)
689 struct vop_info *vi = data;
690 struct mic_bootparam __iomem *bp;
691 struct vop_device *vpdev = vi->vpdev;
693 bp = vpdev->hw_ops->get_remote_dp(vpdev);
694 dev_dbg(&vpdev->dev, "%s %d hotplug work\n",
696 vpdev->hw_ops->ack_interrupt(vpdev, ioread8(&bp->h2c_config_db));
697 schedule_work(&vi->hotplug_work);
701 static int vop_driver_probe(struct vop_device *vpdev)
706 vi = kzalloc(sizeof(*vi), GFP_KERNEL);
711 dev_set_drvdata(&vpdev->dev, vi);
714 mutex_init(&vi->vop_mutex);
715 INIT_WORK(&vi->hotplug_work, vop_hotplug_devices);
717 rc = vop_host_init(vi);
721 struct mic_bootparam __iomem *bootparam;
723 vop_scan_devices(vi, vpdev, !REMOVE_DEVICES);
725 vi->h2c_config_db = vpdev->hw_ops->next_db(vpdev);
726 vi->cookie = vpdev->hw_ops->request_irq(vpdev,
728 "virtio_config_intr",
729 vi, vi->h2c_config_db);
730 if (IS_ERR(vi->cookie)) {
731 rc = PTR_ERR(vi->cookie);
734 bootparam = vpdev->hw_ops->get_remote_dp(vpdev);
735 iowrite8(vi->h2c_config_db, &bootparam->h2c_config_db);
737 vop_init_debugfs(vi);
745 static void vop_driver_remove(struct vop_device *vpdev)
747 struct vop_info *vi = dev_get_drvdata(&vpdev->dev);
752 struct mic_bootparam __iomem *bootparam =
753 vpdev->hw_ops->get_remote_dp(vpdev);
755 iowrite8(-1, &bootparam->h2c_config_db);
756 vpdev->hw_ops->free_irq(vpdev, vi->cookie, vi);
757 flush_work(&vi->hotplug_work);
758 vop_scan_devices(vi, vpdev, REMOVE_DEVICES);
760 vop_exit_debugfs(vi);
764 static struct vop_device_id id_table[] = {
765 { VOP_DEV_TRNSP, VOP_DEV_ANY_ID },
769 static struct vop_driver vop_driver = {
770 .driver.name = KBUILD_MODNAME,
771 .driver.owner = THIS_MODULE,
772 .id_table = id_table,
773 .probe = vop_driver_probe,
774 .remove = vop_driver_remove,
777 module_vop_driver(vop_driver);
779 MODULE_DEVICE_TABLE(mbus, id_table);
780 MODULE_AUTHOR("Intel Corporation");
781 MODULE_DESCRIPTION("Intel(R) Virtio Over PCIe (VOP) driver");
782 MODULE_LICENSE("GPL v2");