diff options
Diffstat (limited to 'drivers/misc/mic/host/mic_virtio.c')
| -rw-r--r-- | drivers/misc/mic/host/mic_virtio.c | 700 |
1 files changed, 700 insertions, 0 deletions
diff --git a/drivers/misc/mic/host/mic_virtio.c b/drivers/misc/mic/host/mic_virtio.c new file mode 100644 index 00000000000..e04bb4fe682 --- /dev/null +++ b/drivers/misc/mic/host/mic_virtio.c @@ -0,0 +1,700 @@ +/* + * Intel MIC Platform Software Stack (MPSS) + * + * Copyright(c) 2013 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". + * + * Intel MIC Host driver. + * + */ +#include <linux/pci.h> +#include <linux/sched.h> +#include <linux/uaccess.h> + +#include <linux/mic_common.h> +#include "../common/mic_dev.h" +#include "mic_device.h" +#include "mic_smpt.h" +#include "mic_virtio.h" + +/* + * Initiates the copies across the PCIe bus from card memory to + * a user space buffer. + */ +static int mic_virtio_copy_to_user(struct mic_vdev *mvdev, + void __user *ubuf, size_t len, u64 addr) +{ + int err; + void __iomem *dbuf = mvdev->mdev->aper.va + addr; + /* + * We are copying from IO below an should ideally use something + * like copy_to_user_fromio(..) if it existed. + */ + if (copy_to_user(ubuf, (void __force *)dbuf, len)) { + err = -EFAULT; + dev_err(mic_dev(mvdev), "%s %d err %d\n", + __func__, __LINE__, err); + goto err; + } + mvdev->in_bytes += len; + err = 0; +err: + return err; +} + +/* + * Initiates copies across the PCIe bus from a user space + * buffer to card memory. + */ +static int mic_virtio_copy_from_user(struct mic_vdev *mvdev, + void __user *ubuf, size_t len, u64 addr) +{ + int err; + void __iomem *dbuf = mvdev->mdev->aper.va + addr; + /* + * We are copying to IO below and should ideally use something + * like copy_from_user_toio(..) if it existed. + */ + if (copy_from_user((void __force *)dbuf, ubuf, len)) { + err = -EFAULT; + dev_err(mic_dev(mvdev), "%s %d err %d\n", + __func__, __LINE__, err); + goto err; + } + mvdev->out_bytes += len; + err = 0; +err: + return err; +} + +#define MIC_VRINGH_READ true + +/* The function to call to notify the card about added buffers */ +static void mic_notify(struct vringh *vrh) +{ + struct mic_vringh *mvrh = container_of(vrh, struct mic_vringh, vrh); + struct mic_vdev *mvdev = mvrh->mvdev; + s8 db = mvdev->dc->h2c_vdev_db; + + if (db != -1) + mvdev->mdev->ops->send_intr(mvdev->mdev, db); +} + +/* Determine the total number of bytes consumed in a VRINGH KIOV */ +static inline u32 mic_vringh_iov_consumed(struct vringh_kiov *iov) +{ + int i; + u32 total = iov->consumed; + + for (i = 0; i < iov->i; i++) + total += iov->iov[i].iov_len; + return total; +} + +/* + * Traverse the VRINGH KIOV and issue the APIs to trigger the copies. + * This API is heavily based on the vringh_iov_xfer(..) implementation + * in vringh.c. The reason we cannot reuse vringh_iov_pull_kern(..) + * and vringh_iov_push_kern(..) directly is because there is no + * way to override the VRINGH xfer(..) routines as of v3.10. + */ +static int mic_vringh_copy(struct mic_vdev *mvdev, struct vringh_kiov *iov, + void __user *ubuf, size_t len, bool read, size_t *out_len) +{ + int ret = 0; + size_t partlen, tot_len = 0; + + while (len && iov->i < iov->used) { + partlen = min(iov->iov[iov->i].iov_len, len); + if (read) + ret = mic_virtio_copy_to_user(mvdev, + ubuf, partlen, + (u64)iov->iov[iov->i].iov_base); + else + ret = mic_virtio_copy_from_user(mvdev, + ubuf, partlen, + (u64)iov->iov[iov->i].iov_base); + if (ret) { + dev_err(mic_dev(mvdev), "%s %d err %d\n", + __func__, __LINE__, ret); + break; + } + len -= partlen; + ubuf += partlen; + tot_len += partlen; + iov->consumed += partlen; + iov->iov[iov->i].iov_len -= partlen; + iov->iov[iov->i].iov_base += partlen; + if (!iov->iov[iov->i].iov_len) { + /* Fix up old iov element then increment. */ + iov->iov[iov->i].iov_len = iov->consumed; + iov->iov[iov->i].iov_base -= iov->consumed; + + iov->consumed = 0; + iov->i++; + } + } + *out_len = tot_len; + return ret; +} + +/* + * Use the standard VRINGH infrastructure in the kernel to fetch new + * descriptors, initiate the copies and update the used ring. + */ +static int _mic_virtio_copy(struct mic_vdev *mvdev, + struct mic_copy_desc *copy) +{ + int ret = 0, iovcnt = copy->iovcnt; + struct iovec iov; + struct iovec __user *u_iov = copy->iov; + void __user *ubuf = NULL; + struct mic_vringh *mvr = &mvdev->mvr[copy->vr_idx]; + struct vringh_kiov *riov = &mvr->riov; + struct vringh_kiov *wiov = &mvr->wiov; + struct vringh *vrh = &mvr->vrh; + u16 *head = &mvr->head; + struct mic_vring *vr = &mvr->vring; + size_t len = 0, out_len; + + copy->out_len = 0; + /* Fetch a new IOVEC if all previous elements have been processed */ + if (riov->i == riov->used && wiov->i == wiov->used) { + ret = vringh_getdesc_kern(vrh, riov, wiov, + head, GFP_KERNEL); + /* Check if there are available descriptors */ + if (ret <= 0) + return ret; + } + while (iovcnt) { + if (!len) { + /* Copy over a new iovec from user space. */ + ret = copy_from_user(&iov, u_iov, sizeof(*u_iov)); + if (ret) { + ret = -EINVAL; + dev_err(mic_dev(mvdev), "%s %d err %d\n", + __func__, __LINE__, ret); + break; + } + len = iov.iov_len; + ubuf = iov.iov_base; + } + /* Issue all the read descriptors first */ + ret = mic_vringh_copy(mvdev, riov, ubuf, len, + MIC_VRINGH_READ, &out_len); + if (ret) { + dev_err(mic_dev(mvdev), "%s %d err %d\n", + __func__, __LINE__, ret); + break; + } + len -= out_len; + ubuf += out_len; + copy->out_len += out_len; + /* Issue the write descriptors next */ + ret = mic_vringh_copy(mvdev, wiov, ubuf, len, + !MIC_VRINGH_READ, &out_len); + if (ret) { + dev_err(mic_dev(mvdev), "%s %d err %d\n", + __func__, __LINE__, ret); + break; + } + len -= out_len; + ubuf += out_len; + copy->out_len += out_len; + if (!len) { + /* One user space iovec is now completed */ + iovcnt--; + u_iov++; + } + /* Exit loop if all elements in KIOVs have been processed. */ + if (riov->i == riov->used && wiov->i == wiov->used) + break; + } + /* + * Update the used ring if a descriptor was available and some data was + * copied in/out and the user asked for a used ring update. + */ + if (*head != USHRT_MAX && copy->out_len && copy->update_used) { + u32 total = 0; + + /* Determine the total data consumed */ + total += mic_vringh_iov_consumed(riov); + total += mic_vringh_iov_consumed(wiov); + vringh_complete_kern(vrh, *head, total); + *head = USHRT_MAX; + if (vringh_need_notify_kern(vrh) > 0) + vringh_notify(vrh); + vringh_kiov_cleanup(riov); + vringh_kiov_cleanup(wiov); + /* Update avail idx for user space */ + vr->info->avail_idx = vrh->last_avail_idx; + } + return ret; +} + +static inline int mic_verify_copy_args(struct mic_vdev *mvdev, + struct mic_copy_desc *copy) +{ + if (copy->vr_idx >= mvdev->dd->num_vq) { + dev_err(mic_dev(mvdev), "%s %d err %d\n", + __func__, __LINE__, -EINVAL); + return -EINVAL; + } + return 0; +} + +/* Copy a specified number of virtio descriptors in a chain */ +int mic_virtio_copy_desc(struct mic_vdev *mvdev, + struct mic_copy_desc *copy) +{ + int err; + struct mic_vringh *mvr = &mvdev->mvr[copy->vr_idx]; + + err = mic_verify_copy_args(mvdev, copy); + if (err) + return err; + + mutex_lock(&mvr->vr_mutex); + if (!mic_vdevup(mvdev)) { + err = -ENODEV; + dev_err(mic_dev(mvdev), "%s %d err %d\n", + __func__, __LINE__, err); + goto err; + } + err = _mic_virtio_copy(mvdev, copy); + if (err) { + dev_err(mic_dev(mvdev), "%s %d err %d\n", + __func__, __LINE__, err); + } +err: + mutex_unlock(&mvr->vr_mutex); + return err; +} + +static void mic_virtio_init_post(struct mic_vdev *mvdev) +{ + struct mic_vqconfig *vqconfig = mic_vq_config(mvdev->dd); + int i; + + for (i = 0; i < mvdev->dd->num_vq; i++) { + if (!le64_to_cpu(vqconfig[i].used_address)) { + dev_warn(mic_dev(mvdev), "used_address zero??\n"); + continue; + } + mvdev->mvr[i].vrh.vring.used = + (void __force *)mvdev->mdev->aper.va + + le64_to_cpu(vqconfig[i].used_address); + } + + mvdev->dc->used_address_updated = 0; + + dev_dbg(mic_dev(mvdev), "%s: device type %d LINKUP\n", + __func__, mvdev->virtio_id); +} + +static inline void mic_virtio_device_reset(struct mic_vdev *mvdev) +{ + int i; + + dev_dbg(mic_dev(mvdev), "%s: status %d device type %d RESET\n", + __func__, mvdev->dd->status, mvdev->virtio_id); + + for (i = 0; i < mvdev->dd->num_vq; i++) + /* + * Avoid lockdep false positive. The + 1 is for the mic + * mutex which is held in the reset devices code path. + */ + mutex_lock_nested(&mvdev->mvr[i].vr_mutex, i + 1); + + /* 0 status means "reset" */ + mvdev->dd->status = 0; + mvdev->dc->vdev_reset = 0; + mvdev->dc->host_ack = 1; + + for (i = 0; i < mvdev->dd->num_vq; i++) { + struct vringh *vrh = &mvdev->mvr[i].vrh; + mvdev->mvr[i].vring.info->avail_idx = 0; + vrh->completed = 0; + vrh->last_avail_idx = 0; + vrh->last_used_idx = 0; + } + + for (i = 0; i < mvdev->dd->num_vq; i++) + mutex_unlock(&mvdev->mvr[i].vr_mutex); +} + +void mic_virtio_reset_devices(struct mic_device *mdev) +{ + struct list_head *pos, *tmp; + struct mic_vdev *mvdev; + + dev_dbg(mdev->sdev->parent, "%s\n", __func__); + + list_for_each_safe(pos, tmp, &mdev->vdev_list) { + mvdev = list_entry(pos, struct mic_vdev, list); + mic_virtio_device_reset(mvdev); + mvdev->poll_wake = 1; + wake_up(&mvdev->waitq); + } +} + +void mic_bh_handler(struct work_struct *work) +{ + struct mic_vdev *mvdev = container_of(work, struct mic_vdev, + virtio_bh_work); + + if (mvdev->dc->used_address_updated) + mic_virtio_init_post(mvdev); + + if (mvdev->dc->vdev_reset) + mic_virtio_device_reset(mvdev); + + mvdev->poll_wake = 1; + wake_up(&mvdev->waitq); +} + +static irqreturn_t mic_virtio_intr_handler(int irq, void *data) +{ + struct mic_vdev *mvdev = data; + struct mic_device *mdev = mvdev->mdev; + + mdev->ops->ack_interrupt(mdev); + schedule_work(&mvdev->virtio_bh_work); + return IRQ_HANDLED; +} + +int mic_virtio_config_change(struct mic_vdev *mvdev, + void __user *argp) +{ + DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake); + int ret = 0, retry, i; + struct mic_bootparam *bootparam = mvdev->mdev->dp; + s8 db = bootparam->h2c_config_db; + + mutex_lock(&mvdev->mdev->mic_mutex); + for (i = 0; i < mvdev->dd->num_vq; i++) + mutex_lock_nested(&mvdev->mvr[i].vr_mutex, i + 1); + + if (db == -1 || mvdev->dd->type == -1) { + ret = -EIO; + goto exit; + } + + if (copy_from_user(mic_vq_configspace(mvdev->dd), + argp, mvdev->dd->config_len)) { + dev_err(mic_dev(mvdev), "%s %d err %d\n", + __func__, __LINE__, -EFAULT); + ret = -EFAULT; + goto exit; + } + mvdev->dc->config_change = MIC_VIRTIO_PARAM_CONFIG_CHANGED; + mvdev->mdev->ops->send_intr(mvdev->mdev, db); + + for (retry = 100; retry--;) { + ret = wait_event_timeout(wake, + mvdev->dc->guest_ack, msecs_to_jiffies(100)); + if (ret) + break; + } + + dev_dbg(mic_dev(mvdev), + "%s %d retry: %d\n", __func__, __LINE__, retry); + mvdev->dc->config_change = 0; + mvdev->dc->guest_ack = 0; +exit: + for (i = 0; i < mvdev->dd->num_vq; i++) + mutex_unlock(&mvdev->mvr[i].vr_mutex); + mutex_unlock(&mvdev->mdev->mic_mutex); + return ret; +} + +static int mic_copy_dp_entry(struct mic_vdev *mvdev, + void __user *argp, + __u8 *type, + struct mic_device_desc **devpage) +{ + struct mic_device *mdev = mvdev->mdev; + struct mic_device_desc dd, *dd_config, *devp; + struct mic_vqconfig *vqconfig; + int ret = 0, i; + bool slot_found = false; + + if (copy_from_user(&dd, argp, sizeof(dd))) { + dev_err(mic_dev(mvdev), "%s %d err %d\n", + __func__, __LINE__, -EFAULT); + return -EFAULT; + } + + if (mic_aligned_desc_size(&dd) > MIC_MAX_DESC_BLK_SIZE || + dd.num_vq > MIC_MAX_VRINGS) { + dev_err(mic_dev(mvdev), "%s %d err %d\n", + __func__, __LINE__, -EINVAL); + return -EINVAL; + } + + dd_config = kmalloc(mic_desc_size(&dd), GFP_KERNEL); + if (dd_config == NULL) { + dev_err(mic_dev(mvdev), "%s %d err %d\n", + __func__, __LINE__, -ENOMEM); + return -ENOMEM; + } + if (copy_from_user(dd_config, argp, mic_desc_size(&dd))) { + ret = -EFAULT; + dev_err(mic_dev(mvdev), "%s %d err %d\n", + __func__, __LINE__, ret); + goto exit; + } + + vqconfig = mic_vq_config(dd_config); + for (i = 0; i < dd.num_vq; i++) { + if (le16_to_cpu(vqconfig[i].num) > MIC_MAX_VRING_ENTRIES) { + ret = -EINVAL; + dev_err(mic_dev(mvdev), "%s %d err %d\n", + __func__, __LINE__, ret); + goto exit; + } + } + + /* Find the first free device page entry */ + for (i = sizeof(struct mic_bootparam); + i < MIC_DP_SIZE - mic_total_desc_size(dd_config); + i += mic_total_desc_size(devp)) { + devp = mdev->dp + i; + if (devp->type == 0 || devp->type == -1) { + slot_found = true; + break; + } + } + if (!slot_found) { + ret = -EINVAL; + dev_err(mic_dev(mvdev), "%s %d err %d\n", + __func__, __LINE__, ret); + goto exit; + } + /* + * Save off the type before doing the memcpy. Type will be set in the + * end after completing all initialization for the new device. + */ + *type = dd_config->type; + dd_config->type = 0; + memcpy(devp, dd_config, mic_desc_size(dd_config)); + + *devpage = devp; +exit: + kfree(dd_config); + return ret; +} + +static void mic_init_device_ctrl(struct mic_vdev *mvdev, + struct mic_device_desc *devpage) +{ + struct mic_device_ctrl *dc; + + dc = (void *)devpage + mic_aligned_desc_size(devpage); + + dc->config_change = 0; + dc->guest_ack = 0; + dc->vdev_reset = 0; + dc->host_ack = 0; + dc->used_address_updated = 0; + dc->c2h_vdev_db = -1; + dc->h2c_vdev_db = -1; + mvdev->dc = dc; +} + +int mic_virtio_add_device(struct mic_vdev *mvdev, + void __user *argp) +{ + struct mic_device *mdev = mvdev->mdev; + struct mic_device_desc *dd = NULL; + struct mic_vqconfig *vqconfig; + int vr_size, i, j, ret; + u8 type = 0; + s8 db; + char irqname[10]; + struct mic_bootparam *bootparam = mdev->dp; + u16 num; + dma_addr_t vr_addr; + + mutex_lock(&mdev->mic_mutex); + + ret = mic_copy_dp_entry(mvdev, argp, &type, &dd); + if (ret) { + mutex_unlock(&mdev->mic_mutex); + return ret; + } + + mic_init_device_ctrl(mvdev, dd); + + mvdev->dd = dd; + mvdev->virtio_id = type; + vqconfig = mic_vq_config(dd); + INIT_WORK(&mvdev->virtio_bh_work, mic_bh_handler); + + for (i = 0; i < dd->num_vq; i++) { + struct mic_vringh *mvr = &mvdev->mvr[i]; + struct mic_vring *vr = &mvdev->mvr[i].vring; + num = le16_to_cpu(vqconfig[i].num); + mutex_init(&mvr->vr_mutex); + vr_size = PAGE_ALIGN(vring_size(num, MIC_VIRTIO_RING_ALIGN) + + sizeof(struct _mic_vring_info)); + vr->va = (void *) + __get_free_pages(GFP_KERNEL | __GFP_ZERO, + get_order(vr_size)); + if (!vr->va) { + ret = -ENOMEM; + dev_err(mic_dev(mvdev), "%s %d err %d\n", + __func__, __LINE__, ret); + goto err; + } + vr->len = vr_size; + vr->info = vr->va + vring_size(num, MIC_VIRTIO_RING_ALIGN); + vr->info->magic = cpu_to_le32(MIC_MAGIC + mvdev->virtio_id + i); + vr_addr = mic_map_single(mdev, vr->va, vr_size); + if (mic_map_error(vr_addr)) { + free_pages((unsigned long)vr->va, get_order(vr_size)); + ret = -ENOMEM; + dev_err(mic_dev(mvdev), "%s %d err %d\n", + __func__, __LINE__, ret); + goto err; + } + vqconfig[i].address = cpu_to_le64(vr_addr); + + vring_init(&vr->vr, num, vr->va, MIC_VIRTIO_RING_ALIGN); + ret = vringh_init_kern(&mvr->vrh, + *(u32 *)mic_vq_features(mvdev->dd), num, false, + vr->vr.desc, vr->vr.avail, vr->vr.used); + if (ret) { + dev_err(mic_dev(mvdev), "%s %d err %d\n", + __func__, __LINE__, ret); + goto err; + } + vringh_kiov_init(&mvr->riov, NULL, 0); + vringh_kiov_init(&mvr->wiov, NULL, 0); + mvr->head = USHRT_MAX; + mvr->mvdev = mvdev; + mvr->vrh.notify = mic_notify; + dev_dbg(mdev->sdev->parent, + "%s %d index %d va %p info %p vr_size 0x%x\n", + __func__, __LINE__, i, vr->va, vr->info, vr_size); + } + + snprintf(irqname, sizeof(irqname), "mic%dvirtio%d", mdev->id, + mvdev->virtio_id); + mvdev->virtio_db = mic_next_db(mdev); + mvdev->virtio_cookie = mic_request_irq(mdev, mic_virtio_intr_handler, + irqname, mvdev, mvdev->virtio_db, MIC_INTR_DB); + if (IS_ERR(mvdev->virtio_cookie)) { + ret = PTR_ERR(mvdev->virtio_cookie); + dev_dbg(mdev->sdev->parent, "request irq failed\n"); + goto err; + } + + mvdev->dc->c2h_vdev_db = mvdev->virtio_db; + + list_add_tail(&mvdev->list, &mdev->vdev_list); + /* + * Order the type update with previous stores. This write barrier + * is paired with the corresponding read barrier before the uncached + * system memory read of the type, on the card while scanning the + * device page. + */ + smp_wmb(); + dd->type = type; + + dev_dbg(mdev->sdev->parent, "Added virtio device id %d\n", dd->type); + + db = bootparam->h2c_config_db; + if (db != -1) + mdev->ops->send_intr(mdev, db); + mutex_unlock(&mdev->mic_mutex); + return 0; +err: + vqconfig = mic_vq_config(dd); + for (j = 0; j < i; j++) { + struct mic_vringh *mvr = &mvdev->mvr[j]; + mic_unmap_single(mdev, le64_to_cpu(vqconfig[j].address), + mvr->vring.len); + free_pages((unsigned long)mvr->vring.va, + get_order(mvr->vring.len)); + } + mutex_unlock(&mdev->mic_mutex); + return ret; +} + +void mic_virtio_del_device(struct mic_vdev *mvdev) +{ + struct list_head *pos, *tmp; + struct mic_vdev *tmp_mvdev; + struct mic_device *mdev = mvdev->mdev; + DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake); + int i, ret, retry; + struct mic_vqconfig *vqconfig; + struct mic_bootparam *bootparam = mdev->dp; + s8 db; + + mutex_lock(&mdev->mic_mutex); + db = bootparam->h2c_config_db; + if (db == -1) + goto skip_hot_remove; + dev_dbg(mdev->sdev->parent, + "Requesting hot remove id %d\n", mvdev->virtio_id); + mvdev->dc->config_change = MIC_VIRTIO_PARAM_DEV_REMOVE; + mdev->ops->send_intr(mdev, db); + for (retry = 100; retry--;) { + ret = wait_event_timeout(wake, + mvdev->dc->guest_ack, msecs_to_jiffies(100)); + if (ret) + break; + } + dev_dbg(mdev->sdev->parent, + "Device id %d config_change %d guest_ack %d retry %d\n", + mvdev->virtio_id, mvdev->dc->config_change, + mvdev->dc->guest_ack, retry); + mvdev->dc->config_change = 0; + mvdev->dc->guest_ack = 0; +skip_hot_remove: + mic_free_irq(mdev, mvdev->virtio_cookie, mvdev); + flush_work(&mvdev->virtio_bh_work); + vqconfig = mic_vq_config(mvdev->dd); + for (i = 0; i < mvdev->dd->num_vq; i++) { + struct mic_vringh *mvr = &mvdev->mvr[i]; + vringh_kiov_cleanup(&mvr->riov); + vringh_kiov_cleanup(&mvr->wiov); + mic_unmap_single(mdev, le64_to_cpu(vqconfig[i].address), + mvr->vring.len); + free_pages((unsigned long)mvr->vring.va, + get_order(mvr->vring.len)); + } + + list_for_each_safe(pos, tmp, &mdev->vdev_list) { + tmp_mvdev = list_entry(pos, struct mic_vdev, list); + if (tmp_mvdev == mvdev) { + list_del(pos); + dev_dbg(mdev->sdev->parent, + "Removing virtio device id %d\n", + mvdev->virtio_id); + break; + } + } + /* + * Order the type update with previous stores. This write barrier + * is paired with the corresponding read barrier before the uncached + * system memory read of the type, on the card while scanning the + * device page. + */ + smp_wmb(); + mvdev->dd->type = -1; + mutex_unlock(&mdev->mic_mutex); +} |