tegrakernel/kernel/kernel-4.9/drivers/misc/mic/vop/vop_vringh.c

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2022-02-16 09:13:02 -06:00
/*
* 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".
*
* Intel Virtio Over PCIe (VOP) driver.
*
*/
#include <linux/sched.h>
#include <linux/poll.h>
#include <linux/dma-mapping.h>
#include <linux/mic_common.h>
#include "../common/mic_dev.h"
#include <linux/mic_ioctl.h>
#include "vop_main.h"
/* Helper API to obtain the VOP PCIe device */
static inline struct device *vop_dev(struct vop_vdev *vdev)
{
return vdev->vpdev->dev.parent;
}
/* Helper API to check if a virtio device is initialized */
static inline int vop_vdev_inited(struct vop_vdev *vdev)
{
if (!vdev)
return -EINVAL;
/* Device has not been created yet */
if (!vdev->dd || !vdev->dd->type) {
dev_err(vop_dev(vdev), "%s %d err %d\n",
__func__, __LINE__, -EINVAL);
return -EINVAL;
}
/* Device has been removed/deleted */
if (vdev->dd->type == -1) {
dev_dbg(vop_dev(vdev), "%s %d err %d\n",
__func__, __LINE__, -ENODEV);
return -ENODEV;
}
return 0;
}
static void _vop_notify(struct vringh *vrh)
{
struct vop_vringh *vvrh = container_of(vrh, struct vop_vringh, vrh);
struct vop_vdev *vdev = vvrh->vdev;
struct vop_device *vpdev = vdev->vpdev;
s8 db = vdev->dc->h2c_vdev_db;
if (db != -1)
vpdev->hw_ops->send_intr(vpdev, db);
}
static void vop_virtio_init_post(struct vop_vdev *vdev)
{
struct mic_vqconfig *vqconfig = mic_vq_config(vdev->dd);
struct vop_device *vpdev = vdev->vpdev;
int i, used_size;
for (i = 0; i < vdev->dd->num_vq; i++) {
used_size = PAGE_ALIGN(sizeof(u16) * 3 +
sizeof(struct vring_used_elem) *
le16_to_cpu(vqconfig->num));
if (!le64_to_cpu(vqconfig[i].used_address)) {
dev_warn(vop_dev(vdev), "used_address zero??\n");
continue;
}
vdev->vvr[i].vrh.vring.used =
(void __force *)vpdev->hw_ops->ioremap(
vpdev,
le64_to_cpu(vqconfig[i].used_address),
used_size);
}
vdev->dc->used_address_updated = 0;
dev_info(vop_dev(vdev), "%s: device type %d LINKUP\n",
__func__, vdev->virtio_id);
}
static inline void vop_virtio_device_reset(struct vop_vdev *vdev)
{
int i;
dev_dbg(vop_dev(vdev), "%s: status %d device type %d RESET\n",
__func__, vdev->dd->status, vdev->virtio_id);
for (i = 0; i < vdev->dd->num_vq; i++)
/*
* Avoid lockdep false positive. The + 1 is for the vop
* mutex which is held in the reset devices code path.
*/
mutex_lock_nested(&vdev->vvr[i].vr_mutex, i + 1);
/* 0 status means "reset" */
vdev->dd->status = 0;
vdev->dc->vdev_reset = 0;
vdev->dc->host_ack = 1;
for (i = 0; i < vdev->dd->num_vq; i++) {
struct vringh *vrh = &vdev->vvr[i].vrh;
vdev->vvr[i].vring.info->avail_idx = 0;
vrh->completed = 0;
vrh->last_avail_idx = 0;
vrh->last_used_idx = 0;
}
for (i = 0; i < vdev->dd->num_vq; i++)
mutex_unlock(&vdev->vvr[i].vr_mutex);
}
static void vop_virtio_reset_devices(struct vop_info *vi)
{
struct list_head *pos, *tmp;
struct vop_vdev *vdev;
list_for_each_safe(pos, tmp, &vi->vdev_list) {
vdev = list_entry(pos, struct vop_vdev, list);
vop_virtio_device_reset(vdev);
vdev->poll_wake = 1;
wake_up(&vdev->waitq);
}
}
static void vop_bh_handler(struct work_struct *work)
{
struct vop_vdev *vdev = container_of(work, struct vop_vdev,
virtio_bh_work);
if (vdev->dc->used_address_updated)
vop_virtio_init_post(vdev);
if (vdev->dc->vdev_reset)
vop_virtio_device_reset(vdev);
vdev->poll_wake = 1;
wake_up(&vdev->waitq);
}
static irqreturn_t _vop_virtio_intr_handler(int irq, void *data)
{
struct vop_vdev *vdev = data;
struct vop_device *vpdev = vdev->vpdev;
vpdev->hw_ops->ack_interrupt(vpdev, vdev->virtio_db);
schedule_work(&vdev->virtio_bh_work);
return IRQ_HANDLED;
}
static int vop_virtio_config_change(struct vop_vdev *vdev, void *argp)
{
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake);
int ret = 0, retry, i;
struct vop_device *vpdev = vdev->vpdev;
struct vop_info *vi = dev_get_drvdata(&vpdev->dev);
struct mic_bootparam *bootparam = vpdev->hw_ops->get_dp(vpdev);
s8 db = bootparam->h2c_config_db;
mutex_lock(&vi->vop_mutex);
for (i = 0; i < vdev->dd->num_vq; i++)
mutex_lock_nested(&vdev->vvr[i].vr_mutex, i + 1);
if (db == -1 || vdev->dd->type == -1) {
ret = -EIO;
goto exit;
}
memcpy(mic_vq_configspace(vdev->dd), argp, vdev->dd->config_len);
vdev->dc->config_change = MIC_VIRTIO_PARAM_CONFIG_CHANGED;
vpdev->hw_ops->send_intr(vpdev, db);
for (retry = 100; retry--;) {
ret = wait_event_timeout(wake, vdev->dc->guest_ack,
msecs_to_jiffies(100));
if (ret)
break;
}
dev_dbg(vop_dev(vdev),
"%s %d retry: %d\n", __func__, __LINE__, retry);
vdev->dc->config_change = 0;
vdev->dc->guest_ack = 0;
exit:
for (i = 0; i < vdev->dd->num_vq; i++)
mutex_unlock(&vdev->vvr[i].vr_mutex);
mutex_unlock(&vi->vop_mutex);
return ret;
}
static int vop_copy_dp_entry(struct vop_vdev *vdev,
struct mic_device_desc *argp, __u8 *type,
struct mic_device_desc **devpage)
{
struct vop_device *vpdev = vdev->vpdev;
struct mic_device_desc *devp;
struct mic_vqconfig *vqconfig;
int ret = 0, i;
bool slot_found = false;
vqconfig = mic_vq_config(argp);
for (i = 0; i < argp->num_vq; i++) {
if (le16_to_cpu(vqconfig[i].num) > MIC_MAX_VRING_ENTRIES) {
ret = -EINVAL;
dev_err(vop_dev(vdev), "%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(argp);
i += mic_total_desc_size(devp)) {
devp = vpdev->hw_ops->get_dp(vpdev) + i;
if (devp->type == 0 || devp->type == -1) {
slot_found = true;
break;
}
}
if (!slot_found) {
ret = -EINVAL;
dev_err(vop_dev(vdev), "%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 = argp->type;
argp->type = 0;
memcpy(devp, argp, mic_desc_size(argp));
*devpage = devp;
exit:
return ret;
}
static void vop_init_device_ctrl(struct vop_vdev *vdev,
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;
vdev->dc = dc;
}
static int vop_virtio_add_device(struct vop_vdev *vdev,
struct mic_device_desc *argp)
{
struct vop_info *vi = vdev->vi;
struct vop_device *vpdev = vi->vpdev;
struct mic_device_desc *dd = NULL;
struct mic_vqconfig *vqconfig;
int vr_size, i, j, ret;
u8 type = 0;
s8 db = -1;
char irqname[16];
struct mic_bootparam *bootparam;
u16 num;
dma_addr_t vr_addr;
bootparam = vpdev->hw_ops->get_dp(vpdev);
init_waitqueue_head(&vdev->waitq);
INIT_LIST_HEAD(&vdev->list);
vdev->vpdev = vpdev;
ret = vop_copy_dp_entry(vdev, argp, &type, &dd);
if (ret) {
dev_err(vop_dev(vdev), "%s %d err %d\n",
__func__, __LINE__, ret);
return ret;
}
vop_init_device_ctrl(vdev, dd);
vdev->dd = dd;
vdev->virtio_id = type;
vqconfig = mic_vq_config(dd);
INIT_WORK(&vdev->virtio_bh_work, vop_bh_handler);
for (i = 0; i < dd->num_vq; i++) {
struct vop_vringh *vvr = &vdev->vvr[i];
struct mic_vring *vr = &vdev->vvr[i].vring;
num = le16_to_cpu(vqconfig[i].num);
mutex_init(&vvr->vr_mutex);
vr_size = PAGE_ALIGN(round_up(vring_size(num, MIC_VIRTIO_RING_ALIGN), 4) +
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(vop_dev(vdev), "%s %d err %d\n",
__func__, __LINE__, ret);
goto err;
}
vr->len = vr_size;
vr->info = vr->va + round_up(vring_size(num, MIC_VIRTIO_RING_ALIGN), 4);
vr->info->magic = cpu_to_le32(MIC_MAGIC + vdev->virtio_id + i);
vr_addr = dma_map_single(&vpdev->dev, vr->va, vr_size,
DMA_BIDIRECTIONAL);
if (dma_mapping_error(&vpdev->dev, vr_addr)) {
free_pages((unsigned long)vr->va, get_order(vr_size));
ret = -ENOMEM;
dev_err(vop_dev(vdev), "%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(&vvr->vrh,
*(u32 *)mic_vq_features(vdev->dd),
num, false, vr->vr.desc, vr->vr.avail,
vr->vr.used);
if (ret) {
dev_err(vop_dev(vdev), "%s %d err %d\n",
__func__, __LINE__, ret);
goto err;
}
vringh_kiov_init(&vvr->riov, NULL, 0);
vringh_kiov_init(&vvr->wiov, NULL, 0);
vvr->head = USHRT_MAX;
vvr->vdev = vdev;
vvr->vrh.notify = _vop_notify;
dev_dbg(&vpdev->dev,
"%s %d index %d va %p info %p vr_size 0x%x\n",
__func__, __LINE__, i, vr->va, vr->info, vr_size);
vvr->buf = (void *)__get_free_pages(GFP_KERNEL,
get_order(VOP_INT_DMA_BUF_SIZE));
vvr->buf_da = dma_map_single(&vpdev->dev,
vvr->buf, VOP_INT_DMA_BUF_SIZE,
DMA_BIDIRECTIONAL);
}
snprintf(irqname, sizeof(irqname), "vop%dvirtio%d", vpdev->index,
vdev->virtio_id);
vdev->virtio_db = vpdev->hw_ops->next_db(vpdev);
vdev->virtio_cookie = vpdev->hw_ops->request_irq(vpdev,
_vop_virtio_intr_handler, irqname, vdev,
vdev->virtio_db);
if (IS_ERR(vdev->virtio_cookie)) {
ret = PTR_ERR(vdev->virtio_cookie);
dev_dbg(&vpdev->dev, "request irq failed\n");
goto err;
}
vdev->dc->c2h_vdev_db = vdev->virtio_db;
/*
* 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;
argp->type = type;
if (bootparam) {
db = bootparam->h2c_config_db;
if (db != -1)
vpdev->hw_ops->send_intr(vpdev, db);
}
dev_dbg(&vpdev->dev, "Added virtio id %d db %d\n", dd->type, db);
return 0;
err:
vqconfig = mic_vq_config(dd);
for (j = 0; j < i; j++) {
struct vop_vringh *vvr = &vdev->vvr[j];
dma_unmap_single(&vpdev->dev, le64_to_cpu(vqconfig[j].address),
vvr->vring.len, DMA_BIDIRECTIONAL);
free_pages((unsigned long)vvr->vring.va,
get_order(vvr->vring.len));
}
return ret;
}
static void vop_dev_remove(struct vop_info *pvi, struct mic_device_ctrl *devp,
struct vop_device *vpdev)
{
struct mic_bootparam *bootparam = vpdev->hw_ops->get_dp(vpdev);
s8 db;
int ret, retry;
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake);
devp->config_change = MIC_VIRTIO_PARAM_DEV_REMOVE;
db = bootparam->h2c_config_db;
if (db != -1)
vpdev->hw_ops->send_intr(vpdev, db);
else
goto done;
for (retry = 15; retry--;) {
ret = wait_event_timeout(wake, devp->guest_ack,
msecs_to_jiffies(1000));
if (ret)
break;
}
done:
devp->config_change = 0;
devp->guest_ack = 0;
}
static void vop_virtio_del_device(struct vop_vdev *vdev)
{
struct vop_info *vi = vdev->vi;
struct vop_device *vpdev = vdev->vpdev;
int i;
struct mic_vqconfig *vqconfig;
struct mic_bootparam *bootparam = vpdev->hw_ops->get_dp(vpdev);
if (!bootparam)
goto skip_hot_remove;
vop_dev_remove(vi, vdev->dc, vpdev);
skip_hot_remove:
vpdev->hw_ops->free_irq(vpdev, vdev->virtio_cookie, vdev);
flush_work(&vdev->virtio_bh_work);
vqconfig = mic_vq_config(vdev->dd);
for (i = 0; i < vdev->dd->num_vq; i++) {
struct vop_vringh *vvr = &vdev->vvr[i];
dma_unmap_single(&vpdev->dev,
vvr->buf_da, VOP_INT_DMA_BUF_SIZE,
DMA_BIDIRECTIONAL);
free_pages((unsigned long)vvr->buf,
get_order(VOP_INT_DMA_BUF_SIZE));
vringh_kiov_cleanup(&vvr->riov);
vringh_kiov_cleanup(&vvr->wiov);
dma_unmap_single(&vpdev->dev, le64_to_cpu(vqconfig[i].address),
vvr->vring.len, DMA_BIDIRECTIONAL);
free_pages((unsigned long)vvr->vring.va,
get_order(vvr->vring.len));
}
/*
* 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();
vdev->dd->type = -1;
}
/*
* vop_sync_dma - Wrapper for synchronous DMAs.
*
* @dev - The address of the pointer to the device instance used
* for DMA registration.
* @dst - destination DMA address.
* @src - source DMA address.
* @len - size of the transfer.
*
* Return DMA_SUCCESS on success
*/
static int vop_sync_dma(struct vop_vdev *vdev, dma_addr_t dst, dma_addr_t src,
size_t len)
{
int err = 0;
struct dma_device *ddev;
struct dma_async_tx_descriptor *tx;
struct vop_info *vi = dev_get_drvdata(&vdev->vpdev->dev);
struct dma_chan *vop_ch = vi->dma_ch;
if (!vop_ch) {
err = -EBUSY;
goto error;
}
ddev = vop_ch->device;
tx = ddev->device_prep_dma_memcpy(vop_ch, dst, src, len,
DMA_PREP_FENCE);
if (!tx) {
err = -ENOMEM;
goto error;
} else {
dma_cookie_t cookie;
cookie = tx->tx_submit(tx);
if (dma_submit_error(cookie)) {
err = -ENOMEM;
goto error;
}
dma_async_issue_pending(vop_ch);
err = dma_sync_wait(vop_ch, cookie);
}
error:
if (err)
dev_err(&vi->vpdev->dev, "%s %d err %d\n",
__func__, __LINE__, err);
return err;
}
#define VOP_USE_DMA true
/*
* Initiates the copies across the PCIe bus from card memory to a user
* space buffer. When transfers are done using DMA, source/destination
* addresses and transfer length must follow the alignment requirements of
* the MIC DMA engine.
*/
static int vop_virtio_copy_to_user(struct vop_vdev *vdev, void __user *ubuf,
size_t len, u64 daddr, size_t dlen,
int vr_idx)
{
struct vop_device *vpdev = vdev->vpdev;
void __iomem *dbuf = vpdev->hw_ops->ioremap(vpdev, daddr, len);
struct vop_vringh *vvr = &vdev->vvr[vr_idx];
struct vop_info *vi = dev_get_drvdata(&vpdev->dev);
size_t dma_alignment = 1 << vi->dma_ch->device->copy_align;
bool x200 = is_dma_copy_aligned(vi->dma_ch->device, 1, 1, 1);
size_t dma_offset, partlen;
int err;
if (!VOP_USE_DMA) {
if (copy_to_user(ubuf, (void __force *)dbuf, len)) {
err = -EFAULT;
dev_err(vop_dev(vdev), "%s %d err %d\n",
__func__, __LINE__, err);
goto err;
}
vdev->in_bytes += len;
err = 0;
goto err;
}
dma_offset = daddr - round_down(daddr, dma_alignment);
daddr -= dma_offset;
len += dma_offset;
/*
* X100 uses DMA addresses as seen by the card so adding
* the aperture base is not required for DMA. However x200
* requires DMA addresses to be an offset into the bar so
* add the aperture base for x200.
*/
if (x200)
daddr += vpdev->aper->pa;
while (len) {
partlen = min_t(size_t, len, VOP_INT_DMA_BUF_SIZE);
err = vop_sync_dma(vdev, vvr->buf_da, daddr,
ALIGN(partlen, dma_alignment));
if (err) {
dev_err(vop_dev(vdev), "%s %d err %d\n",
__func__, __LINE__, err);
goto err;
}
if (copy_to_user(ubuf, vvr->buf + dma_offset,
partlen - dma_offset)) {
err = -EFAULT;
dev_err(vop_dev(vdev), "%s %d err %d\n",
__func__, __LINE__, err);
goto err;
}
daddr += partlen;
ubuf += partlen;
dbuf += partlen;
vdev->in_bytes_dma += partlen;
vdev->in_bytes += partlen;
len -= partlen;
dma_offset = 0;
}
err = 0;
err:
vpdev->hw_ops->iounmap(vpdev, dbuf);
dev_dbg(vop_dev(vdev),
"%s: ubuf %p dbuf %p len 0x%lx vr_idx 0x%x\n",
__func__, ubuf, dbuf, len, vr_idx);
return err;
}
/*
* Initiates copies across the PCIe bus from a user space buffer to card
* memory. When transfers are done using DMA, source/destination addresses
* and transfer length must follow the alignment requirements of the MIC
* DMA engine.
*/
static int vop_virtio_copy_from_user(struct vop_vdev *vdev, void __user *ubuf,
size_t len, u64 daddr, size_t dlen,
int vr_idx)
{
struct vop_device *vpdev = vdev->vpdev;
void __iomem *dbuf = vpdev->hw_ops->ioremap(vpdev, daddr, len);
struct vop_vringh *vvr = &vdev->vvr[vr_idx];
struct vop_info *vi = dev_get_drvdata(&vdev->vpdev->dev);
size_t dma_alignment = 1 << vi->dma_ch->device->copy_align;
bool x200 = is_dma_copy_aligned(vi->dma_ch->device, 1, 1, 1);
size_t partlen;
bool dma = VOP_USE_DMA;
int err = 0;
size_t offset = 0;
if (daddr & (dma_alignment - 1)) {
vdev->tx_dst_unaligned += len;
dma = false;
} else if (ALIGN(len, dma_alignment) > dlen) {
vdev->tx_len_unaligned += len;
dma = false;
}
if (!dma)
goto memcpy;
/*
* X100 uses DMA addresses as seen by the card so adding
* the aperture base is not required for DMA. However x200
* requires DMA addresses to be an offset into the bar so
* add the aperture base for x200.
*/
if (x200)
daddr += vpdev->aper->pa;
while (len) {
partlen = min_t(size_t, len, VOP_INT_DMA_BUF_SIZE);
if (copy_from_user(vvr->buf, ubuf, partlen)) {
err = -EFAULT;
dev_err(vop_dev(vdev), "%s %d err %d\n",
__func__, __LINE__, err);
goto err;
}
err = vop_sync_dma(vdev, daddr, vvr->buf_da,
ALIGN(partlen, dma_alignment));
if (err) {
dev_err(vop_dev(vdev), "%s %d err %d\n",
__func__, __LINE__, err);
goto err;
}
daddr += partlen;
ubuf += partlen;
dbuf += partlen;
vdev->out_bytes_dma += partlen;
vdev->out_bytes += partlen;
len -= partlen;
}
memcpy:
/*
* We are copying to IO below and should ideally use something
* like copy_from_user_toio(..) if it existed.
*/
while (len) {
partlen = min_t(size_t, len, VOP_INT_DMA_BUF_SIZE);
if (copy_from_user(vvr->buf, ubuf + offset, partlen)) {
err = -EFAULT;
dev_err(vop_dev(vdev), "%s %d err %d\n",
__func__, __LINE__, err);
goto err;
}
memcpy_toio(dbuf + offset, vvr->buf, partlen);
offset += partlen;
vdev->out_bytes += partlen;
len -= partlen;
}
err = 0;
err:
vpdev->hw_ops->iounmap(vpdev, dbuf);
dev_dbg(vop_dev(vdev),
"%s: ubuf %p dbuf %p len 0x%lx vr_idx 0x%x\n",
__func__, ubuf, dbuf, len, vr_idx);
return err;
}
#define MIC_VRINGH_READ true
/* Determine the total number of bytes consumed in a VRINGH KIOV */
static inline u32 vop_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 vop_vringh_copy(struct vop_vdev *vdev, struct vringh_kiov *iov,
void __user *ubuf, size_t len, bool read, int vr_idx,
size_t *out_len)
{
int ret = 0;
size_t partlen, tot_len = 0;
while (len && iov->i < iov->used) {
struct kvec *kiov = &iov->iov[iov->i];
partlen = min(kiov->iov_len, len);
if (read)
ret = vop_virtio_copy_to_user(vdev, ubuf, partlen,
(u64)kiov->iov_base,
kiov->iov_len,
vr_idx);
else
ret = vop_virtio_copy_from_user(vdev, ubuf, partlen,
(u64)kiov->iov_base,
kiov->iov_len,
vr_idx);
if (ret) {
dev_err(vop_dev(vdev), "%s %d err %d\n",
__func__, __LINE__, ret);
break;
}
len -= partlen;
ubuf += partlen;
tot_len += partlen;
iov->consumed += partlen;
kiov->iov_len -= partlen;
kiov->iov_base += partlen;
if (!kiov->iov_len) {
/* Fix up old iov element then increment. */
kiov->iov_len = iov->consumed;
kiov->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 _vop_virtio_copy(struct vop_vdev *vdev, struct mic_copy_desc *copy)
{
int ret = 0;
u32 iovcnt = copy->iovcnt;
struct iovec iov;
struct iovec __user *u_iov = copy->iov;
void __user *ubuf = NULL;
struct vop_vringh *vvr = &vdev->vvr[copy->vr_idx];
struct vringh_kiov *riov = &vvr->riov;
struct vringh_kiov *wiov = &vvr->wiov;
struct vringh *vrh = &vvr->vrh;
u16 *head = &vvr->head;
struct mic_vring *vr = &vvr->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(vop_dev(vdev), "%s %d err %d\n",
__func__, __LINE__, ret);
break;
}
len = iov.iov_len;
ubuf = iov.iov_base;
}
/* Issue all the read descriptors first */
ret = vop_vringh_copy(vdev, riov, ubuf, len,
MIC_VRINGH_READ, copy->vr_idx, &out_len);
if (ret) {
dev_err(vop_dev(vdev), "%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 = vop_vringh_copy(vdev, wiov, ubuf, len,
!MIC_VRINGH_READ, copy->vr_idx, &out_len);
if (ret) {
dev_err(vop_dev(vdev), "%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 += vop_vringh_iov_consumed(riov);
total += vop_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 vop_verify_copy_args(struct vop_vdev *vdev,
struct mic_copy_desc *copy)
{
if (!vdev || copy->vr_idx >= vdev->dd->num_vq)
return -EINVAL;
return 0;
}
/* Copy a specified number of virtio descriptors in a chain */
static int vop_virtio_copy_desc(struct vop_vdev *vdev,
struct mic_copy_desc *copy)
{
int err;
struct vop_vringh *vvr;
err = vop_verify_copy_args(vdev, copy);
if (err)
return err;
vvr = &vdev->vvr[copy->vr_idx];
mutex_lock(&vvr->vr_mutex);
if (!vop_vdevup(vdev)) {
err = -ENODEV;
dev_err(vop_dev(vdev), "%s %d err %d\n",
__func__, __LINE__, err);
goto err;
}
err = _vop_virtio_copy(vdev, copy);
if (err) {
dev_err(vop_dev(vdev), "%s %d err %d\n",
__func__, __LINE__, err);
}
err:
mutex_unlock(&vvr->vr_mutex);
return err;
}
static int vop_open(struct inode *inode, struct file *f)
{
struct vop_vdev *vdev;
struct vop_info *vi = container_of(f->private_data,
struct vop_info, miscdev);
vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
if (!vdev)
return -ENOMEM;
vdev->vi = vi;
mutex_init(&vdev->vdev_mutex);
f->private_data = vdev;
init_completion(&vdev->destroy);
complete(&vdev->destroy);
return 0;
}
static int vop_release(struct inode *inode, struct file *f)
{
struct vop_vdev *vdev = f->private_data, *vdev_tmp;
struct vop_info *vi = vdev->vi;
struct list_head *pos, *tmp;
bool found = false;
mutex_lock(&vdev->vdev_mutex);
if (vdev->deleted)
goto unlock;
mutex_lock(&vi->vop_mutex);
list_for_each_safe(pos, tmp, &vi->vdev_list) {
vdev_tmp = list_entry(pos, struct vop_vdev, list);
if (vdev == vdev_tmp) {
vop_virtio_del_device(vdev);
list_del(pos);
found = true;
break;
}
}
mutex_unlock(&vi->vop_mutex);
unlock:
mutex_unlock(&vdev->vdev_mutex);
if (!found)
wait_for_completion(&vdev->destroy);
f->private_data = NULL;
kfree(vdev);
return 0;
}
static long vop_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
{
struct vop_vdev *vdev = f->private_data;
struct vop_info *vi = vdev->vi;
void __user *argp = (void __user *)arg;
int ret;
switch (cmd) {
case MIC_VIRTIO_ADD_DEVICE:
{
struct mic_device_desc dd, *dd_config;
if (copy_from_user(&dd, argp, sizeof(dd)))
return -EFAULT;
if (mic_aligned_desc_size(&dd) > MIC_MAX_DESC_BLK_SIZE ||
dd.num_vq > MIC_MAX_VRINGS)
return -EINVAL;
dd_config = kzalloc(mic_desc_size(&dd), GFP_KERNEL);
if (!dd_config)
return -ENOMEM;
if (copy_from_user(dd_config, argp, mic_desc_size(&dd))) {
ret = -EFAULT;
goto free_ret;
}
/* Ensure desc has not changed between the two reads */
if (memcmp(&dd, dd_config, sizeof(dd))) {
ret = -EINVAL;
goto free_ret;
}
mutex_lock(&vdev->vdev_mutex);
mutex_lock(&vi->vop_mutex);
ret = vop_virtio_add_device(vdev, dd_config);
if (ret)
goto unlock_ret;
list_add_tail(&vdev->list, &vi->vdev_list);
unlock_ret:
mutex_unlock(&vi->vop_mutex);
mutex_unlock(&vdev->vdev_mutex);
free_ret:
kfree(dd_config);
return ret;
}
case MIC_VIRTIO_COPY_DESC:
{
struct mic_copy_desc copy;
mutex_lock(&vdev->vdev_mutex);
ret = vop_vdev_inited(vdev);
if (ret)
goto _unlock_ret;
if (copy_from_user(&copy, argp, sizeof(copy))) {
ret = -EFAULT;
goto _unlock_ret;
}
ret = vop_virtio_copy_desc(vdev, &copy);
if (ret < 0)
goto _unlock_ret;
if (copy_to_user(
&((struct mic_copy_desc __user *)argp)->out_len,
&copy.out_len, sizeof(copy.out_len)))
ret = -EFAULT;
_unlock_ret:
mutex_unlock(&vdev->vdev_mutex);
return ret;
}
case MIC_VIRTIO_CONFIG_CHANGE:
{
void *buf;
mutex_lock(&vdev->vdev_mutex);
ret = vop_vdev_inited(vdev);
if (ret)
goto __unlock_ret;
buf = kzalloc(vdev->dd->config_len, GFP_KERNEL);
if (!buf) {
ret = -ENOMEM;
goto __unlock_ret;
}
if (copy_from_user(buf, argp, vdev->dd->config_len)) {
ret = -EFAULT;
goto done;
}
ret = vop_virtio_config_change(vdev, buf);
done:
kfree(buf);
__unlock_ret:
mutex_unlock(&vdev->vdev_mutex);
return ret;
}
default:
return -ENOIOCTLCMD;
};
return 0;
}
/*
* We return POLLIN | POLLOUT from poll when new buffers are enqueued, and
* not when previously enqueued buffers may be available. This means that
* in the card->host (TX) path, when userspace is unblocked by poll it
* must drain all available descriptors or it can stall.
*/
static unsigned int vop_poll(struct file *f, poll_table *wait)
{
struct vop_vdev *vdev = f->private_data;
int mask = 0;
mutex_lock(&vdev->vdev_mutex);
if (vop_vdev_inited(vdev)) {
mask = POLLERR;
goto done;
}
poll_wait(f, &vdev->waitq, wait);
if (vop_vdev_inited(vdev)) {
mask = POLLERR;
} else if (vdev->poll_wake) {
vdev->poll_wake = 0;
mask = POLLIN | POLLOUT;
}
done:
mutex_unlock(&vdev->vdev_mutex);
return mask;
}
static inline int
vop_query_offset(struct vop_vdev *vdev, unsigned long offset,
unsigned long *size, unsigned long *pa)
{
struct vop_device *vpdev = vdev->vpdev;
unsigned long start = MIC_DP_SIZE;
int i;
/*
* MMAP interface is as follows:
* offset region
* 0x0 virtio device_page
* 0x1000 first vring
* 0x1000 + size of 1st vring second vring
* ....
*/
if (!offset) {
*pa = virt_to_phys(vpdev->hw_ops->get_dp(vpdev));
*size = MIC_DP_SIZE;
return 0;
}
for (i = 0; i < vdev->dd->num_vq; i++) {
struct vop_vringh *vvr = &vdev->vvr[i];
if (offset == start) {
*pa = virt_to_phys(vvr->vring.va);
*size = vvr->vring.len;
return 0;
}
start += vvr->vring.len;
}
return -1;
}
/*
* Maps the device page and virtio rings to user space for readonly access.
*/
static int vop_mmap(struct file *f, struct vm_area_struct *vma)
{
struct vop_vdev *vdev = f->private_data;
unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
unsigned long pa, size = vma->vm_end - vma->vm_start, size_rem = size;
int i, err;
err = vop_vdev_inited(vdev);
if (err)
goto ret;
if (vma->vm_flags & VM_WRITE) {
err = -EACCES;
goto ret;
}
while (size_rem) {
i = vop_query_offset(vdev, offset, &size, &pa);
if (i < 0) {
err = -EINVAL;
goto ret;
}
err = remap_pfn_range(vma, vma->vm_start + offset,
pa >> PAGE_SHIFT, size,
vma->vm_page_prot);
if (err)
goto ret;
size_rem -= size;
offset += size;
}
ret:
return err;
}
static const struct file_operations vop_fops = {
.open = vop_open,
.release = vop_release,
.unlocked_ioctl = vop_ioctl,
.poll = vop_poll,
.mmap = vop_mmap,
.owner = THIS_MODULE,
};
int vop_host_init(struct vop_info *vi)
{
int rc;
struct miscdevice *mdev;
struct vop_device *vpdev = vi->vpdev;
INIT_LIST_HEAD(&vi->vdev_list);
vi->dma_ch = vpdev->dma_ch;
mdev = &vi->miscdev;
mdev->minor = MISC_DYNAMIC_MINOR;
snprintf(vi->name, sizeof(vi->name), "vop_virtio%d", vpdev->index);
mdev->name = vi->name;
mdev->fops = &vop_fops;
mdev->parent = &vpdev->dev;
rc = misc_register(mdev);
if (rc)
dev_err(&vpdev->dev, "%s failed rc %d\n", __func__, rc);
return rc;
}
void vop_host_uninit(struct vop_info *vi)
{
struct list_head *pos, *tmp;
struct vop_vdev *vdev;
mutex_lock(&vi->vop_mutex);
vop_virtio_reset_devices(vi);
list_for_each_safe(pos, tmp, &vi->vdev_list) {
vdev = list_entry(pos, struct vop_vdev, list);
list_del(pos);
reinit_completion(&vdev->destroy);
mutex_unlock(&vi->vop_mutex);
mutex_lock(&vdev->vdev_mutex);
vop_virtio_del_device(vdev);
vdev->deleted = true;
mutex_unlock(&vdev->vdev_mutex);
complete(&vdev->destroy);
mutex_lock(&vi->vop_mutex);
}
mutex_unlock(&vi->vop_mutex);
misc_deregister(&vi->miscdev);
}