/*
* 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, 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(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 =
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 = 100, 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 (i = retry; i--;) {
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 = mic_aligned_size(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;
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 = MIC_MAGIC + mvdev->virtio_id + i;
vqconfig[i].address = mic_map_single(mdev,
vr->va, vr_size);
if (mic_map_error(vqconfig[i].address)) {
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(vqconfig[i].address);
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 = 100;
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 (i = retry; i--;) {
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\n",
mvdev->virtio_id, mvdev->dc->config_change,
mvdev->dc->guest_ack);
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);
}
