/* * Intel MIC Platform Software Stack (MPSS) * * Copyright(c) 2016 Intel Corporation. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License, version 2, as * published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * The full GNU General Public License is included in this distribution in * the file called "COPYING". * * Adapted from: * * virtio for kvm on s390 * * Copyright IBM Corp. 2008 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License (version 2 only) * as published by the Free Software Foundation. * * Author(s): Christian Borntraeger * * Intel Virtio Over PCIe (VOP) driver. * */ #include #include #include #include #include "vop_main.h" #define VOP_MAX_VRINGS 4 /* * _vop_vdev - Allocated per virtio device instance injected by the peer. * * @vdev: Virtio device * @desc: Virtio device page descriptor * @dc: Virtio device control * @vpdev: VOP device which is the parent for this virtio device * @vr: Buffer for accessing the VRING * @used: Buffer for used * @used_size: Size of the used buffer * @reset_done: Track whether VOP reset is complete * @virtio_cookie: Cookie returned upon requesting a interrupt * @c2h_vdev_db: The doorbell used by the guest to interrupt the host * @h2c_vdev_db: The doorbell used by the host to interrupt the guest * @dnode: The destination node */ struct _vop_vdev { struct virtio_device vdev; struct mic_device_desc __iomem *desc; struct mic_device_ctrl __iomem *dc; struct vop_device *vpdev; void __iomem *vr[VOP_MAX_VRINGS]; dma_addr_t used[VOP_MAX_VRINGS]; int used_size[VOP_MAX_VRINGS]; struct completion reset_done; struct mic_irq *virtio_cookie; int c2h_vdev_db; int h2c_vdev_db; int dnode; }; #define to_vopvdev(vd) container_of(vd, struct _vop_vdev, vdev) #define _vop_aligned_desc_size(d) __mic_align(_vop_desc_size(d), 8) /* Helper API to obtain the parent of the virtio device */ static inline struct device *_vop_dev(struct _vop_vdev *vdev) { return vdev->vdev.dev.parent; } static inline unsigned _vop_desc_size(struct mic_device_desc __iomem *desc) { return sizeof(*desc) + ioread8(&desc->num_vq) * sizeof(struct mic_vqconfig) + ioread8(&desc->feature_len) * 2 + ioread8(&desc->config_len); } static inline struct mic_vqconfig __iomem * _vop_vq_config(struct mic_device_desc __iomem *desc) { return (struct mic_vqconfig __iomem *)(desc + 1); } static inline u8 __iomem * _vop_vq_features(struct mic_device_desc __iomem *desc) { return (u8 __iomem *)(_vop_vq_config(desc) + ioread8(&desc->num_vq)); } static inline u8 __iomem * _vop_vq_configspace(struct mic_device_desc __iomem *desc) { return _vop_vq_features(desc) + ioread8(&desc->feature_len) * 2; } static inline unsigned _vop_total_desc_size(struct mic_device_desc __iomem *desc) { return _vop_aligned_desc_size(desc) + sizeof(struct mic_device_ctrl); } /* This gets the device's feature bits. */ static u64 vop_get_features(struct virtio_device *vdev) { unsigned int i, bits; u32 features = 0; struct mic_device_desc __iomem *desc = to_vopvdev(vdev)->desc; u8 __iomem *in_features = _vop_vq_features(desc); int feature_len = ioread8(&desc->feature_len); bits = min_t(unsigned, feature_len, sizeof(vdev->features)) * 8; for (i = 0; i < bits; i++) if (ioread8(&in_features[i / 8]) & (BIT(i % 8))) features |= BIT(i); return features; } static int vop_finalize_features(struct virtio_device *vdev) { unsigned int i, bits; struct mic_device_desc __iomem *desc = to_vopvdev(vdev)->desc; u8 feature_len = ioread8(&desc->feature_len); /* Second half of bitmap is features we accept. */ u8 __iomem *out_features = _vop_vq_features(desc) + feature_len; /* Give virtio_ring a chance to accept features. */ vring_transport_features(vdev); memset_io(out_features, 0, feature_len); bits = min_t(unsigned, feature_len, sizeof(vdev->features)) * 8; for (i = 0; i < bits; i++) { if (__virtio_test_bit(vdev, i)) iowrite8(ioread8(&out_features[i / 8]) | (1 << (i % 8)), &out_features[i / 8]); } return 0; } /* * Reading and writing elements in config space */ static void vop_get(struct virtio_device *vdev, unsigned int offset, void *buf, unsigned len) { struct mic_device_desc __iomem *desc = to_vopvdev(vdev)->desc; if (offset + len > ioread8(&desc->config_len)) return; memcpy_fromio(buf, _vop_vq_configspace(desc) + offset, len); } static void vop_set(struct virtio_device *vdev, unsigned int offset, const void *buf, unsigned len) { struct mic_device_desc __iomem *desc = to_vopvdev(vdev)->desc; if (offset + len > ioread8(&desc->config_len)) return; memcpy_toio(_vop_vq_configspace(desc) + offset, buf, len); } /* * The operations to get and set the status word just access the status * field of the device descriptor. set_status also interrupts the host * to tell about status changes. */ static u8 vop_get_status(struct virtio_device *vdev) { return ioread8(&to_vopvdev(vdev)->desc->status); } static void vop_set_status(struct virtio_device *dev, u8 status) { struct _vop_vdev *vdev = to_vopvdev(dev); struct vop_device *vpdev = vdev->vpdev; if (!status) return; iowrite8(status, &vdev->desc->status); vpdev->hw_ops->send_intr(vpdev, vdev->c2h_vdev_db); } /* Inform host on a virtio device reset and wait for ack from host */ static void vop_reset_inform_host(struct virtio_device *dev) { struct _vop_vdev *vdev = to_vopvdev(dev); struct mic_device_ctrl __iomem *dc = vdev->dc; struct vop_device *vpdev = vdev->vpdev; int retry; iowrite8(0, &dc->host_ack); iowrite8(1, &dc->vdev_reset); vpdev->hw_ops->send_intr(vpdev, vdev->c2h_vdev_db); /* Wait till host completes all card accesses and acks the reset */ for (retry = 100; retry--;) { if (ioread8(&dc->host_ack)) break; msleep(100); }; dev_dbg(_vop_dev(vdev), "%s: retry: %d\n", __func__, retry); /* Reset status to 0 in case we timed out */ iowrite8(0, &vdev->desc->status); } static void vop_reset(struct virtio_device *dev) { struct _vop_vdev *vdev = to_vopvdev(dev); dev_dbg(_vop_dev(vdev), "%s: virtio id %d\n", __func__, dev->id.device); vop_reset_inform_host(dev); complete_all(&vdev->reset_done); } /* * The virtio_ring code calls this API when it wants to notify the Host. */ static bool vop_notify(struct virtqueue *vq) { struct _vop_vdev *vdev = vq->priv; struct vop_device *vpdev = vdev->vpdev; vpdev->hw_ops->send_intr(vpdev, vdev->c2h_vdev_db); return true; } static void vop_del_vq(struct virtqueue *vq, int n) { struct _vop_vdev *vdev = to_vopvdev(vq->vdev); struct vring *vr = (struct vring *)(vq + 1); struct vop_device *vpdev = vdev->vpdev; dma_unmap_single(&vpdev->dev, vdev->used[n], vdev->used_size[n], DMA_BIDIRECTIONAL); free_pages((unsigned long)vr->used, get_order(vdev->used_size[n])); vring_del_virtqueue(vq); vpdev->hw_ops->iounmap(vpdev, vdev->vr[n]); vdev->vr[n] = NULL; } static void vop_del_vqs(struct virtio_device *dev) { struct _vop_vdev *vdev = to_vopvdev(dev); struct virtqueue *vq, *n; int idx = 0; dev_dbg(_vop_dev(vdev), "%s\n", __func__); list_for_each_entry_safe(vq, n, &dev->vqs, list) vop_del_vq(vq, idx++); } /* * This routine will assign vring's allocated in host/io memory. Code in * virtio_ring.c however continues to access this io memory as if it were local * memory without io accessors. */ static struct virtqueue *vop_find_vq(struct virtio_device *dev, unsigned index, void (*callback)(struct virtqueue *vq), const char *name, bool ctx) { struct _vop_vdev *vdev = to_vopvdev(dev); struct vop_device *vpdev = vdev->vpdev; struct mic_vqconfig __iomem *vqconfig; struct mic_vqconfig config; struct virtqueue *vq; void __iomem *va; struct _mic_vring_info __iomem *info; void *used; int vr_size, _vr_size, err, magic; struct vring *vr; u8 type = ioread8(&vdev->desc->type); if (index >= ioread8(&vdev->desc->num_vq)) return ERR_PTR(-ENOENT); if (!name) return ERR_PTR(-ENOENT); /* First assign the vring's allocated in host memory */ vqconfig = _vop_vq_config(vdev->desc) + index; memcpy_fromio(&config, vqconfig, sizeof(config)); _vr_size = round_up(vring_size(le16_to_cpu(config.num), MIC_VIRTIO_RING_ALIGN), 4); vr_size = PAGE_ALIGN(_vr_size + sizeof(struct _mic_vring_info)); va = vpdev->hw_ops->ioremap(vpdev, le64_to_cpu(config.address), vr_size); if (!va) return ERR_PTR(-ENOMEM); vdev->vr[index] = va; memset_io(va, 0x0, _vr_size); vq = vring_new_virtqueue( index, le16_to_cpu(config.num), MIC_VIRTIO_RING_ALIGN, dev, false, ctx, (void __force *)va, vop_notify, callback, name); if (!vq) { err = -ENOMEM; goto unmap; } info = va + _vr_size; magic = ioread32(&info->magic); if (WARN(magic != MIC_MAGIC + type + index, "magic mismatch")) { err = -EIO; goto unmap; } /* Allocate and reassign used ring now */ vdev->used_size[index] = PAGE_ALIGN(sizeof(__u16) * 3 + sizeof(struct vring_used_elem) * le16_to_cpu(config.num)); used = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, get_order(vdev->used_size[index])); if (!used) { err = -ENOMEM; dev_err(_vop_dev(vdev), "%s %d err %d\n", __func__, __LINE__, err); goto del_vq; } vdev->used[index] = dma_map_single(&vpdev->dev, used, vdev->used_size[index], DMA_BIDIRECTIONAL); if (dma_mapping_error(&vpdev->dev, vdev->used[index])) { err = -ENOMEM; dev_err(_vop_dev(vdev), "%s %d err %d\n", __func__, __LINE__, err); goto free_used; } writeq(vdev->used[index], &vqconfig->used_address); /* * To reassign the used ring here we are directly accessing * struct vring_virtqueue which is a private data structure * in virtio_ring.c. At the minimum, a BUILD_BUG_ON() in * vring_new_virtqueue() would ensure that * (&vq->vring == (struct vring *) (&vq->vq + 1)); */ vr = (struct vring *)(vq + 1); vr->used = used; vq->priv = vdev; return vq; free_used: free_pages((unsigned long)used, get_order(vdev->used_size[index])); del_vq: vring_del_virtqueue(vq); unmap: vpdev->hw_ops->iounmap(vpdev, vdev->vr[index]); return ERR_PTR(err); } static int vop_find_vqs(struct virtio_device *dev, unsigned nvqs, struct virtqueue *vqs[], vq_callback_t *callbacks[], const char * const names[], const bool *ctx, struct irq_affinity *desc) { struct _vop_vdev *vdev = to_vopvdev(dev); struct vop_device *vpdev = vdev->vpdev; struct mic_device_ctrl __iomem *dc = vdev->dc; int i, err, retry; /* We must have this many virtqueues. */ if (nvqs > ioread8(&vdev->desc->num_vq)) return -ENOENT; for (i = 0; i < nvqs; ++i) { dev_dbg(_vop_dev(vdev), "%s: %d: %s\n", __func__, i, names[i]); vqs[i] = vop_find_vq(dev, i, callbacks[i], names[i], ctx ? ctx[i] : false); if (IS_ERR(vqs[i])) { err = PTR_ERR(vqs[i]); goto error; } } iowrite8(1, &dc->used_address_updated); /* * Send an interrupt to the host to inform it that used * rings have been re-assigned. */ vpdev->hw_ops->send_intr(vpdev, vdev->c2h_vdev_db); for (retry = 100; --retry;) { if (!ioread8(&dc->used_address_updated)) break; msleep(100); }; dev_dbg(_vop_dev(vdev), "%s: retry: %d\n", __func__, retry); if (!retry) { err = -ENODEV; goto error; } return 0; error: vop_del_vqs(dev); return err; } /* * The config ops structure as defined by virtio config */ static struct virtio_config_ops vop_vq_config_ops = { .get_features = vop_get_features, .finalize_features = vop_finalize_features, .get = vop_get, .set = vop_set, .get_status = vop_get_status, .set_status = vop_set_status, .reset = vop_reset, .find_vqs = vop_find_vqs, .del_vqs = vop_del_vqs, }; static irqreturn_t vop_virtio_intr_handler(int irq, void *data) { struct _vop_vdev *vdev = data; struct vop_device *vpdev = vdev->vpdev; struct virtqueue *vq; vpdev->hw_ops->ack_interrupt(vpdev, vdev->h2c_vdev_db); list_for_each_entry(vq, &vdev->vdev.vqs, list) vring_interrupt(0, vq); return IRQ_HANDLED; } static void vop_virtio_release_dev(struct device *_d) { /* * No need for a release method similar to virtio PCI. * Provide an empty one to avoid getting a warning from core. */ } /* * adds a new device and register it with virtio * appropriate drivers are loaded by the device model */ static int _vop_add_device(struct mic_device_desc __iomem *d, unsigned int offset, struct vop_device *vpdev, int dnode) { struct _vop_vdev *vdev; int ret; u8 type = ioread8(&d->type); vdev = kzalloc(sizeof(*vdev), GFP_KERNEL); if (!vdev) return -ENOMEM; vdev->vpdev = vpdev; vdev->vdev.dev.parent = &vpdev->dev; vdev->vdev.dev.release = vop_virtio_release_dev; vdev->vdev.id.device = type; vdev->vdev.config = &vop_vq_config_ops; vdev->desc = d; vdev->dc = (void __iomem *)d + _vop_aligned_desc_size(d); vdev->dnode = dnode; vdev->vdev.priv = (void *)(u64)dnode; init_completion(&vdev->reset_done); vdev->h2c_vdev_db = vpdev->hw_ops->next_db(vpdev); vdev->virtio_cookie = vpdev->hw_ops->request_irq(vpdev, vop_virtio_intr_handler, "virtio intr", vdev, vdev->h2c_vdev_db); if (IS_ERR(vdev->virtio_cookie)) { ret = PTR_ERR(vdev->virtio_cookie); goto kfree; } iowrite8((u8)vdev->h2c_vdev_db, &vdev->dc->h2c_vdev_db); vdev->c2h_vdev_db = ioread8(&vdev->dc->c2h_vdev_db); ret = register_virtio_device(&vdev->vdev); if (ret) { dev_err(_vop_dev(vdev), "Failed to register vop device %u type %u\n", offset, type); goto free_irq; } writeq((u64)vdev, &vdev->dc->vdev); dev_dbg(_vop_dev(vdev), "%s: registered vop device %u type %u vdev %p\n", __func__, offset, type, vdev); return 0; free_irq: vpdev->hw_ops->free_irq(vpdev, vdev->virtio_cookie, vdev); kfree: kfree(vdev); return ret; } /* * match for a vop device with a specific desc pointer */ static int vop_match_desc(struct device *dev, void *data) { struct virtio_device *_dev = dev_to_virtio(dev); struct _vop_vdev *vdev = to_vopvdev(_dev); return vdev->desc == (void __iomem *)data; } static void _vop_handle_config_change(struct mic_device_desc __iomem *d, unsigned int offset, struct vop_device *vpdev) { struct mic_device_ctrl __iomem *dc = (void __iomem *)d + _vop_aligned_desc_size(d); struct _vop_vdev *vdev = (struct _vop_vdev *)readq(&dc->vdev); if (ioread8(&dc->config_change) != MIC_VIRTIO_PARAM_CONFIG_CHANGED) return; dev_dbg(&vpdev->dev, "%s %d\n", __func__, __LINE__); virtio_config_changed(&vdev->vdev); iowrite8(1, &dc->guest_ack); } /* * removes a virtio device if a hot remove event has been * requested by the host. */ static int _vop_remove_device(struct mic_device_desc __iomem *d, unsigned int offset, struct vop_device *vpdev) { struct mic_device_ctrl __iomem *dc = (void __iomem *)d + _vop_aligned_desc_size(d); struct _vop_vdev *vdev = (struct _vop_vdev *)readq(&dc->vdev); u8 status; int ret = -1; if (ioread8(&dc->config_change) == MIC_VIRTIO_PARAM_DEV_REMOVE) { dev_dbg(&vpdev->dev, "%s %d config_change %d type %d vdev %p\n", __func__, __LINE__, ioread8(&dc->config_change), ioread8(&d->type), vdev); status = ioread8(&d->status); reinit_completion(&vdev->reset_done); unregister_virtio_device(&vdev->vdev); vpdev->hw_ops->free_irq(vpdev, vdev->virtio_cookie, vdev); iowrite8(-1, &dc->h2c_vdev_db); if (status & VIRTIO_CONFIG_S_DRIVER_OK) wait_for_completion(&vdev->reset_done); kfree(vdev); iowrite8(1, &dc->guest_ack); dev_dbg(&vpdev->dev, "%s %d guest_ack %d\n", __func__, __LINE__, ioread8(&dc->guest_ack)); iowrite8(-1, &d->type); ret = 0; } return ret; } #define REMOVE_DEVICES true static void _vop_scan_devices(void __iomem *dp, struct vop_device *vpdev, bool remove, int dnode) { s8 type; unsigned int i; struct mic_device_desc __iomem *d; struct mic_device_ctrl __iomem *dc; struct device *dev; int ret; for (i = sizeof(struct mic_bootparam); i < MIC_DP_SIZE; i += _vop_total_desc_size(d)) { d = dp + i; dc = (void __iomem *)d + _vop_aligned_desc_size(d); /* * This read barrier is paired with the corresponding write * barrier on the host which is inserted before adding or * removing a virtio device descriptor, by updating the type. */ rmb(); type = ioread8(&d->type); /* end of list */ if (type == 0) break; if (type == -1) continue; /* device already exists */ dev = device_find_child(&vpdev->dev, (void __force *)d, vop_match_desc); if (dev) { if (remove) iowrite8(MIC_VIRTIO_PARAM_DEV_REMOVE, &dc->config_change); put_device(dev); _vop_handle_config_change(d, i, vpdev); ret = _vop_remove_device(d, i, vpdev); if (remove) { iowrite8(0, &dc->config_change); iowrite8(0, &dc->guest_ack); } continue; } /* new device */ dev_dbg(&vpdev->dev, "%s %d Adding new virtio device %p\n", __func__, __LINE__, d); if (!remove) _vop_add_device(d, i, vpdev, dnode); } } static void vop_scan_devices(struct vop_info *vi, struct vop_device *vpdev, bool remove) { void __iomem *dp = vpdev->hw_ops->get_remote_dp(vpdev); if (!dp) return; mutex_lock(&vi->vop_mutex); _vop_scan_devices(dp, vpdev, remove, vpdev->dnode); mutex_unlock(&vi->vop_mutex); } /* * vop_hotplug_device tries to find changes in the device page. */ static void vop_hotplug_devices(struct work_struct *work) { struct vop_info *vi = container_of(work, struct vop_info, hotplug_work); vop_scan_devices(vi, vi->vpdev, !REMOVE_DEVICES); } /* * Interrupt handler for hot plug/config changes etc. */ static irqreturn_t vop_extint_handler(int irq, void *data) { struct vop_info *vi = data; struct mic_bootparam __iomem *bp; struct vop_device *vpdev = vi->vpdev; bp = vpdev->hw_ops->get_remote_dp(vpdev); dev_dbg(&vpdev->dev, "%s %d hotplug work\n", __func__, __LINE__); vpdev->hw_ops->ack_interrupt(vpdev, ioread8(&bp->h2c_config_db)); schedule_work(&vi->hotplug_work); return IRQ_HANDLED; } static int vop_driver_probe(struct vop_device *vpdev) { struct vop_info *vi; int rc; vi = kzalloc(sizeof(*vi), GFP_KERNEL); if (!vi) { rc = -ENOMEM; goto exit; } dev_set_drvdata(&vpdev->dev, vi); vi->vpdev = vpdev; mutex_init(&vi->vop_mutex); INIT_WORK(&vi->hotplug_work, vop_hotplug_devices); if (vpdev->dnode) { rc = vop_host_init(vi); if (rc < 0) goto free; } else { struct mic_bootparam __iomem *bootparam; vop_scan_devices(vi, vpdev, !REMOVE_DEVICES); vi->h2c_config_db = vpdev->hw_ops->next_db(vpdev); vi->cookie = vpdev->hw_ops->request_irq(vpdev, vop_extint_handler, "virtio_config_intr", vi, vi->h2c_config_db); if (IS_ERR(vi->cookie)) { rc = PTR_ERR(vi->cookie); goto free; } bootparam = vpdev->hw_ops->get_remote_dp(vpdev); iowrite8(vi->h2c_config_db, &bootparam->h2c_config_db); } vop_init_debugfs(vi); return 0; free: kfree(vi); exit: return rc; } static void vop_driver_remove(struct vop_device *vpdev) { struct vop_info *vi = dev_get_drvdata(&vpdev->dev); if (vpdev->dnode) { vop_host_uninit(vi); } else { struct mic_bootparam __iomem *bootparam = vpdev->hw_ops->get_remote_dp(vpdev); if (bootparam) iowrite8(-1, &bootparam->h2c_config_db); vpdev->hw_ops->free_irq(vpdev, vi->cookie, vi); flush_work(&vi->hotplug_work); vop_scan_devices(vi, vpdev, REMOVE_DEVICES); } vop_exit_debugfs(vi); kfree(vi); } static struct vop_device_id id_table[] = { { VOP_DEV_TRNSP, VOP_DEV_ANY_ID }, { 0 }, }; static struct vop_driver vop_driver = { .driver.name = KBUILD_MODNAME, .driver.owner = THIS_MODULE, .id_table = id_table, .probe = vop_driver_probe, .remove = vop_driver_remove, }; module_vop_driver(vop_driver); MODULE_DEVICE_TABLE(mbus, id_table); MODULE_AUTHOR("Intel Corporation"); MODULE_DESCRIPTION("Intel(R) Virtio Over PCIe (VOP) driver"); MODULE_LICENSE("GPL v2");