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linux/drivers/virtio/virtio_pci_modern.c
Jason Wang 6e52fc446d virtio-pci-modern: introduce helper for getting queue nums 
This patch introduces helper for getting queue num of modern device.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-14-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-02-23 07:52:58 -05:00

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Virtio PCI driver - modern (virtio 1.0) device support
*
* This module allows virtio devices to be used over a virtual PCI device.
* This can be used with QEMU based VMMs like KVM or Xen.
*
* Copyright IBM Corp. 2007
* Copyright Red Hat, Inc. 2014
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
* Rusty Russell <rusty@rustcorp.com.au>
* Michael S. Tsirkin <mst@redhat.com>
*/
#include <linux/delay.h>
#define VIRTIO_PCI_NO_LEGACY
#define VIRTIO_RING_NO_LEGACY
#include "virtio_pci_common.h"
/*
* Type-safe wrappers for io accesses.
* Use these to enforce at compile time the following spec requirement:
*
* The driver MUST access each field using the “natural” access
* method, i.e. 32-bit accesses for 32-bit fields, 16-bit accesses
* for 16-bit fields and 8-bit accesses for 8-bit fields.
*/
static inline u8 vp_ioread8(const u8 __iomem *addr)
{
return ioread8(addr);
}
static inline u16 vp_ioread16 (const __le16 __iomem *addr)
{
return ioread16(addr);
}
static inline u32 vp_ioread32(const __le32 __iomem *addr)
{
return ioread32(addr);
}
static inline void vp_iowrite8(u8 value, u8 __iomem *addr)
{
iowrite8(value, addr);
}
static inline void vp_iowrite16(u16 value, __le16 __iomem *addr)
{
iowrite16(value, addr);
}
static inline void vp_iowrite32(u32 value, __le32 __iomem *addr)
{
iowrite32(value, addr);
}
static void vp_iowrite64_twopart(u64 val,
__le32 __iomem *lo, __le32 __iomem *hi)
{
vp_iowrite32((u32)val, lo);
vp_iowrite32(val >> 32, hi);
}
static void __iomem *map_capability(struct pci_dev *dev, int off,
size_t minlen,
u32 align,
u32 start, u32 size,
size_t *len)
{
u8 bar;
u32 offset, length;
void __iomem *p;
pci_read_config_byte(dev, off + offsetof(struct virtio_pci_cap,
bar),
&bar);
pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, offset),
&offset);
pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, length),
&length);
if (length <= start) {
dev_err(&dev->dev,
"virtio_pci: bad capability len %u (>%u expected)\n",
length, start);
return NULL;
}
if (length - start < minlen) {
dev_err(&dev->dev,
"virtio_pci: bad capability len %u (>=%zu expected)\n",
length, minlen);
return NULL;
}
length -= start;
if (start + offset < offset) {
dev_err(&dev->dev,
"virtio_pci: map wrap-around %u+%u\n",
start, offset);
return NULL;
}
offset += start;
if (offset & (align - 1)) {
dev_err(&dev->dev,
"virtio_pci: offset %u not aligned to %u\n",
offset, align);
return NULL;
}
if (length > size)
length = size;
if (len)
*len = length;
if (minlen + offset < minlen ||
minlen + offset > pci_resource_len(dev, bar)) {
dev_err(&dev->dev,
"virtio_pci: map virtio %zu@%u "
"out of range on bar %i length %lu\n",
minlen, offset,
bar, (unsigned long)pci_resource_len(dev, bar));
return NULL;
}
p = pci_iomap_range(dev, bar, offset, length);
if (!p)
dev_err(&dev->dev,
"virtio_pci: unable to map virtio %u@%u on bar %i\n",
length, offset, bar);
return p;
}
/*
* vp_modern_get_features - get features from device
* @mdev: the modern virtio-pci device
*
* Returns the features read from the device
*/
static u64 vp_modern_get_features(struct virtio_pci_modern_device *mdev)
{
struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
u64 features;
vp_iowrite32(0, &cfg->device_feature_select);
features = vp_ioread32(&cfg->device_feature);
vp_iowrite32(1, &cfg->device_feature_select);
features |= ((u64)vp_ioread32(&cfg->device_feature) << 32);
return features;
}
/* virtio config->get_features() implementation */
static u64 vp_get_features(struct virtio_device *vdev)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
return vp_modern_get_features(&vp_dev->mdev);
}
static void vp_transport_features(struct virtio_device *vdev, u64 features)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
struct pci_dev *pci_dev = vp_dev->pci_dev;
if ((features & BIT_ULL(VIRTIO_F_SR_IOV)) &&
pci_find_ext_capability(pci_dev, PCI_EXT_CAP_ID_SRIOV))
__virtio_set_bit(vdev, VIRTIO_F_SR_IOV);
}
/*
* vp_modern_set_features - set features to device
* @mdev: the modern virtio-pci device
* @features: the features set to device
*/
static void vp_modern_set_features(struct virtio_pci_modern_device *mdev,
u64 features)
{
struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
vp_iowrite32(0, &cfg->guest_feature_select);
vp_iowrite32((u32)features, &cfg->guest_feature);
vp_iowrite32(1, &cfg->guest_feature_select);
vp_iowrite32(features >> 32, &cfg->guest_feature);
}
/*
* vp_modern_queue_vector - set the MSIX vector for a specific virtqueue
* @mdev: the modern virtio-pci device
* @index: queue index
* @vector: the config vector
*
* Returns the config vector read from the device
*/
static u16 vp_modern_queue_vector(struct virtio_pci_modern_device *mdev,
u16 index, u16 vector)
{
struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
vp_iowrite16(index, &cfg->queue_select);
vp_iowrite16(vector, &cfg->queue_msix_vector);
/* Flush the write out to device */
return vp_ioread16(&cfg->queue_msix_vector);
}
/*
* vp_modern_queue_address - set the virtqueue address
* @mdev: the modern virtio-pci device
* @index: the queue index
* @desc_addr: address of the descriptor area
* @driver_addr: address of the driver area
* @device_addr: address of the device area
*/
static void vp_modern_queue_address(struct virtio_pci_modern_device *mdev,
u16 index, u64 desc_addr, u64 driver_addr,
u64 device_addr)
{
struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
vp_iowrite16(index, &cfg->queue_select);
vp_iowrite64_twopart(desc_addr, &cfg->queue_desc_lo,
&cfg->queue_desc_hi);
vp_iowrite64_twopart(driver_addr, &cfg->queue_avail_lo,
&cfg->queue_avail_hi);
vp_iowrite64_twopart(device_addr, &cfg->queue_used_lo,
&cfg->queue_used_hi);
}
/*
* vp_modern_set_queue_enable - enable a virtqueue
* @mdev: the modern virtio-pci device
* @index: the queue index
* @enable: whether the virtqueue is enable or not
*/
static void vp_modern_set_queue_enable(struct virtio_pci_modern_device *mdev,
u16 index, bool enable)
{
vp_iowrite16(index, &mdev->common->queue_select);
vp_iowrite16(enable, &mdev->common->queue_enable);
}
/*
* vp_modern_get_queue_enable - enable a virtqueue
* @mdev: the modern virtio-pci device
* @index: the queue index
*
* Returns whether a virtqueue is enabled or not
*/
static bool vp_modern_get_queue_enable(struct virtio_pci_modern_device *mdev,
u16 index)
{
vp_iowrite16(index, &mdev->common->queue_select);
return vp_ioread16(&mdev->common->queue_enable);
}
/*
* vp_modern_set_queue_size - set size for a virtqueue
* @mdev: the modern virtio-pci device
* @index: the queue index
* @size: the size of the virtqueue
*/
static void vp_modern_set_queue_size(struct virtio_pci_modern_device *mdev,
u16 index, u16 size)
{
vp_iowrite16(index, &mdev->common->queue_select);
vp_iowrite16(size, &mdev->common->queue_size);
}
/*
* vp_modern_get_queue_size - get size for a virtqueue
* @mdev: the modern virtio-pci device
* @index: the queue index
*
* Returns the size of the virtqueue
*/
static u16 vp_modern_get_queue_size(struct virtio_pci_modern_device *mdev,
u16 index)
{
vp_iowrite16(index, &mdev->common->queue_select);
return vp_ioread16(&mdev->common->queue_size);
}
/*
* vp_modern_get_num_queues - get the number of virtqueues
* @mdev: the modern virtio-pci device
*
* Returns the number of virtqueues
*/
static u16 vp_modern_get_num_queues(struct virtio_pci_modern_device *mdev)
{
return vp_ioread16(&mdev->common->num_queues);
}
/* virtio config->finalize_features() implementation */
static int vp_finalize_features(struct virtio_device *vdev)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
u64 features = vdev->features;
/* Give virtio_ring a chance to accept features. */
vring_transport_features(vdev);
/* Give virtio_pci a chance to accept features. */
vp_transport_features(vdev, features);
if (!__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
dev_err(&vdev->dev, "virtio: device uses modern interface "
"but does not have VIRTIO_F_VERSION_1\n");
return -EINVAL;
}
vp_modern_set_features(&vp_dev->mdev, vdev->features);
return 0;
}
/* virtio config->get() implementation */
static void vp_get(struct virtio_device *vdev, unsigned offset,
void *buf, unsigned len)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
void __iomem *device = mdev->device;
u8 b;
__le16 w;
__le32 l;
BUG_ON(offset + len > mdev->device_len);
switch (len) {
case 1:
b = ioread8(device + offset);
memcpy(buf, &b, sizeof b);
break;
case 2:
w = cpu_to_le16(ioread16(device + offset));
memcpy(buf, &w, sizeof w);
break;
case 4:
l = cpu_to_le32(ioread32(device + offset));
memcpy(buf, &l, sizeof l);
break;
case 8:
l = cpu_to_le32(ioread32(device + offset));
memcpy(buf, &l, sizeof l);
l = cpu_to_le32(ioread32(device + offset + sizeof l));
memcpy(buf + sizeof l, &l, sizeof l);
break;
default:
BUG();
}
}
/* the config->set() implementation. it's symmetric to the config->get()
* implementation */
static void vp_set(struct virtio_device *vdev, unsigned offset,
const void *buf, unsigned len)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
void __iomem *device = mdev->device;
u8 b;
__le16 w;
__le32 l;
BUG_ON(offset + len > mdev->device_len);
switch (len) {
case 1:
memcpy(&b, buf, sizeof b);
iowrite8(b, device + offset);
break;
case 2:
memcpy(&w, buf, sizeof w);
iowrite16(le16_to_cpu(w), device + offset);
break;
case 4:
memcpy(&l, buf, sizeof l);
iowrite32(le32_to_cpu(l), device + offset);
break;
case 8:
memcpy(&l, buf, sizeof l);
iowrite32(le32_to_cpu(l), device + offset);
memcpy(&l, buf + sizeof l, sizeof l);
iowrite32(le32_to_cpu(l), device + offset + sizeof l);
break;
default:
BUG();
}
}
/*
* vp_modern_generation - get the device genreation
* @mdev: the modern virtio-pci device
*
* Returns the genreation read from device
*/
static u32 vp_modern_generation(struct virtio_pci_modern_device *mdev)
{
struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
return vp_ioread8(&cfg->config_generation);
}
static u32 vp_generation(struct virtio_device *vdev)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
return vp_modern_generation(&vp_dev->mdev);
}
/*
* vp_modern_get_status - get the device status
* @mdev: the modern virtio-pci device
*
* Returns the status read from device
*/
static u8 vp_modern_get_status(struct virtio_pci_modern_device *mdev)
{
struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
return vp_ioread8(&cfg->device_status);
}
/* config->{get,set}_status() implementations */
static u8 vp_get_status(struct virtio_device *vdev)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
return vp_modern_get_status(&vp_dev->mdev);
}
/*
* vp_modern_set_status - set status to device
* @mdev: the modern virtio-pci device
* @status: the status set to device
*/
static void vp_modern_set_status(struct virtio_pci_modern_device *mdev,
u8 status)
{
struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
vp_iowrite8(status, &cfg->device_status);
}
static void vp_set_status(struct virtio_device *vdev, u8 status)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
/* We should never be setting status to 0. */
BUG_ON(status == 0);
vp_modern_set_status(&vp_dev->mdev, status);
}
static void vp_reset(struct virtio_device *vdev)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
/* 0 status means a reset. */
vp_modern_set_status(mdev, 0);
/* After writing 0 to device_status, the driver MUST wait for a read of
* device_status to return 0 before reinitializing the device.
* This will flush out the status write, and flush in device writes,
* including MSI-X interrupts, if any.
*/
while (vp_modern_get_status(mdev))
msleep(1);
/* Flush pending VQ/configuration callbacks. */
vp_synchronize_vectors(vdev);
}
/*
* vp_modern_config_vector - set the vector for config interrupt
* @mdev: the modern virtio-pci device
* @vector: the config vector
*
* Returns the config vector read from the device
*/
static u16 vp_modern_config_vector(struct virtio_pci_modern_device *mdev,
u16 vector)
{
struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
/* Setup the vector used for configuration events */
vp_iowrite16(vector, &cfg->msix_config);
/* Verify we had enough resources to assign the vector */
/* Will also flush the write out to device */
return vp_ioread16(&cfg->msix_config);
}
static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
{
return vp_modern_config_vector(&vp_dev->mdev, vector);
}
static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
struct virtio_pci_vq_info *info,
unsigned index,
void (*callback)(struct virtqueue *vq),
const char *name,
bool ctx,
u16 msix_vec)
{
struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
struct virtqueue *vq;
u16 num, off;
int err;
if (index >= vp_modern_get_num_queues(mdev))
return ERR_PTR(-ENOENT);
/* Select the queue we're interested in */
vp_iowrite16(index, &cfg->queue_select);
/* Check if queue is either not available or already active. */
num = vp_modern_get_queue_size(mdev, index);
if (!num || vp_modern_get_queue_enable(mdev, index))
return ERR_PTR(-ENOENT);
if (num & (num - 1)) {
dev_warn(&vp_dev->pci_dev->dev, "bad queue size %u", num);
return ERR_PTR(-EINVAL);
}
/* get offset of notification word for this vq */
off = vp_ioread16(&cfg->queue_notify_off);
info->msix_vector = msix_vec;
/* create the vring */
vq = vring_create_virtqueue(index, num,
SMP_CACHE_BYTES, &vp_dev->vdev,
true, true, ctx,
vp_notify, callback, name);
if (!vq)
return ERR_PTR(-ENOMEM);
/* activate the queue */
vp_modern_set_queue_size(mdev, index, virtqueue_get_vring_size(vq));
vp_modern_queue_address(mdev, index, virtqueue_get_desc_addr(vq),
virtqueue_get_avail_addr(vq),
virtqueue_get_used_addr(vq));
if (mdev->notify_base) {
/* offset should not wrap */
if ((u64)off * mdev->notify_offset_multiplier + 2
> mdev->notify_len) {
dev_warn(&mdev->pci_dev->dev,
"bad notification offset %u (x %u) "
"for queue %u > %zd",
off, mdev->notify_offset_multiplier,
index, mdev->notify_len);
err = -EINVAL;
goto err_map_notify;
}
vq->priv = (void __force *)mdev->notify_base +
off * mdev->notify_offset_multiplier;
} else {
vq->priv = (void __force *)map_capability(mdev->pci_dev,
mdev->notify_map_cap, 2, 2,
off * mdev->notify_offset_multiplier, 2,
NULL);
}
if (!vq->priv) {
err = -ENOMEM;
goto err_map_notify;
}
if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
msix_vec = vp_modern_queue_vector(mdev, index, msix_vec);
if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
err = -EBUSY;
goto err_assign_vector;
}
}
return vq;
err_assign_vector:
if (!mdev->notify_base)
pci_iounmap(mdev->pci_dev, (void __iomem __force *)vq->priv);
err_map_notify:
vring_del_virtqueue(vq);
return ERR_PTR(err);
}
static int vp_modern_find_vqs(struct virtio_device *vdev, unsigned nvqs,
struct virtqueue *vqs[],
vq_callback_t *callbacks[],
const char * const names[], const bool *ctx,
struct irq_affinity *desc)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
struct virtqueue *vq;
int rc = vp_find_vqs(vdev, nvqs, vqs, callbacks, names, ctx, desc);
if (rc)
return rc;
/* Select and activate all queues. Has to be done last: once we do
* this, there's no way to go back except reset.
*/
list_for_each_entry(vq, &vdev->vqs, list)
vp_modern_set_queue_enable(&vp_dev->mdev, vq->index, true);
return 0;
}
static void del_vq(struct virtio_pci_vq_info *info)
{
struct virtqueue *vq = info->vq;
struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
if (vp_dev->msix_enabled)
vp_modern_queue_vector(mdev, vq->index,
VIRTIO_MSI_NO_VECTOR);
if (!mdev->notify_base)
pci_iounmap(mdev->pci_dev, (void __force __iomem *)vq->priv);
vring_del_virtqueue(vq);
}
static int virtio_pci_find_shm_cap(struct pci_dev *dev, u8 required_id,
u8 *bar, u64 *offset, u64 *len)
{
int pos;
for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR); pos > 0;
pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) {
u8 type, cap_len, id;
u32 tmp32;
u64 res_offset, res_length;
pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
cfg_type), &type);
if (type != VIRTIO_PCI_CAP_SHARED_MEMORY_CFG)
continue;
pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
cap_len), &cap_len);
if (cap_len != sizeof(struct virtio_pci_cap64)) {
dev_err(&dev->dev, "%s: shm cap with bad size offset:"
" %d size: %d\n", __func__, pos, cap_len);
continue;
}
pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
id), &id);
if (id != required_id)
continue;
/* Type, and ID match, looks good */
pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
bar), bar);
/* Read the lower 32bit of length and offset */
pci_read_config_dword(dev, pos + offsetof(struct virtio_pci_cap,
offset), &tmp32);
res_offset = tmp32;
pci_read_config_dword(dev, pos + offsetof(struct virtio_pci_cap,
length), &tmp32);
res_length = tmp32;
/* and now the top half */
pci_read_config_dword(dev,
pos + offsetof(struct virtio_pci_cap64,
offset_hi), &tmp32);
res_offset |= ((u64)tmp32) << 32;
pci_read_config_dword(dev,
pos + offsetof(struct virtio_pci_cap64,
length_hi), &tmp32);
res_length |= ((u64)tmp32) << 32;
*offset = res_offset;
*len = res_length;
return pos;
}
return 0;
}
static bool vp_get_shm_region(struct virtio_device *vdev,
struct virtio_shm_region *region, u8 id)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
struct pci_dev *pci_dev = vp_dev->pci_dev;
u8 bar;
u64 offset, len;
phys_addr_t phys_addr;
size_t bar_len;
if (!virtio_pci_find_shm_cap(pci_dev, id, &bar, &offset, &len))
return false;
phys_addr = pci_resource_start(pci_dev, bar);
bar_len = pci_resource_len(pci_dev, bar);
if ((offset + len) < offset) {
dev_err(&pci_dev->dev, "%s: cap offset+len overflow detected\n",
__func__);
return false;
}
if (offset + len > bar_len) {
dev_err(&pci_dev->dev, "%s: bar shorter than cap offset+len\n",
__func__);
return false;
}
region->len = len;
region->addr = (u64) phys_addr + offset;
return true;
}
static const struct virtio_config_ops virtio_pci_config_nodev_ops = {
.get = NULL,
.set = NULL,
.generation = vp_generation,
.get_status = vp_get_status,
.set_status = vp_set_status,
.reset = vp_reset,
.find_vqs = vp_modern_find_vqs,
.del_vqs = vp_del_vqs,
.get_features = vp_get_features,
.finalize_features = vp_finalize_features,
.bus_name = vp_bus_name,
.set_vq_affinity = vp_set_vq_affinity,
.get_vq_affinity = vp_get_vq_affinity,
.get_shm_region = vp_get_shm_region,
};
static const struct virtio_config_ops virtio_pci_config_ops = {
.get = vp_get,
.set = vp_set,
.generation = vp_generation,
.get_status = vp_get_status,
.set_status = vp_set_status,
.reset = vp_reset,
.find_vqs = vp_modern_find_vqs,
.del_vqs = vp_del_vqs,
.get_features = vp_get_features,
.finalize_features = vp_finalize_features,
.bus_name = vp_bus_name,
.set_vq_affinity = vp_set_vq_affinity,
.get_vq_affinity = vp_get_vq_affinity,
.get_shm_region = vp_get_shm_region,
};
/**
* virtio_pci_find_capability - walk capabilities to find device info.
* @dev: the pci device
* @cfg_type: the VIRTIO_PCI_CAP_* value we seek
* @ioresource_types: IORESOURCE_MEM and/or IORESOURCE_IO.
* @bars: the bitmask of BARs
*
* Returns offset of the capability, or 0.
*/
static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type,
u32 ioresource_types, int *bars)
{
int pos;
for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
pos > 0;
pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) {
u8 type, bar;
pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
cfg_type),
&type);
pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
bar),
&bar);
/* Ignore structures with reserved BAR values */
if (bar > 0x5)
continue;
if (type == cfg_type) {
if (pci_resource_len(dev, bar) &&
pci_resource_flags(dev, bar) & ioresource_types) {
*bars |= (1 << bar);
return pos;
}
}
}
return 0;
}
/* This is part of the ABI. Don't screw with it. */
static inline void check_offsets(void)
{
/* Note: disk space was harmed in compilation of this function. */
BUILD_BUG_ON(VIRTIO_PCI_CAP_VNDR !=
offsetof(struct virtio_pci_cap, cap_vndr));
BUILD_BUG_ON(VIRTIO_PCI_CAP_NEXT !=
offsetof(struct virtio_pci_cap, cap_next));
BUILD_BUG_ON(VIRTIO_PCI_CAP_LEN !=
offsetof(struct virtio_pci_cap, cap_len));
BUILD_BUG_ON(VIRTIO_PCI_CAP_CFG_TYPE !=
offsetof(struct virtio_pci_cap, cfg_type));
BUILD_BUG_ON(VIRTIO_PCI_CAP_BAR !=
offsetof(struct virtio_pci_cap, bar));
BUILD_BUG_ON(VIRTIO_PCI_CAP_OFFSET !=
offsetof(struct virtio_pci_cap, offset));
BUILD_BUG_ON(VIRTIO_PCI_CAP_LENGTH !=
offsetof(struct virtio_pci_cap, length));
BUILD_BUG_ON(VIRTIO_PCI_NOTIFY_CAP_MULT !=
offsetof(struct virtio_pci_notify_cap,
notify_off_multiplier));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_DFSELECT !=
offsetof(struct virtio_pci_common_cfg,
device_feature_select));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_DF !=
offsetof(struct virtio_pci_common_cfg, device_feature));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_GFSELECT !=
offsetof(struct virtio_pci_common_cfg,
guest_feature_select));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_GF !=
offsetof(struct virtio_pci_common_cfg, guest_feature));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_MSIX !=
offsetof(struct virtio_pci_common_cfg, msix_config));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_NUMQ !=
offsetof(struct virtio_pci_common_cfg, num_queues));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_STATUS !=
offsetof(struct virtio_pci_common_cfg, device_status));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_CFGGENERATION !=
offsetof(struct virtio_pci_common_cfg, config_generation));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SELECT !=
offsetof(struct virtio_pci_common_cfg, queue_select));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SIZE !=
offsetof(struct virtio_pci_common_cfg, queue_size));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_MSIX !=
offsetof(struct virtio_pci_common_cfg, queue_msix_vector));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_ENABLE !=
offsetof(struct virtio_pci_common_cfg, queue_enable));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_NOFF !=
offsetof(struct virtio_pci_common_cfg, queue_notify_off));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCLO !=
offsetof(struct virtio_pci_common_cfg, queue_desc_lo));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCHI !=
offsetof(struct virtio_pci_common_cfg, queue_desc_hi));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILLO !=
offsetof(struct virtio_pci_common_cfg, queue_avail_lo));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILHI !=
offsetof(struct virtio_pci_common_cfg, queue_avail_hi));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDLO !=
offsetof(struct virtio_pci_common_cfg, queue_used_lo));
BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDHI !=
offsetof(struct virtio_pci_common_cfg, queue_used_hi));
}
/*
* vp_modern_probe: probe the modern virtio pci device, note that the
* caller is required to enable PCI device before calling this function.
* @mdev: the modern virtio-pci device
*
* Return 0 on succeed otherwise fail
*/
static int vp_modern_probe(struct virtio_pci_modern_device *mdev)
{
struct pci_dev *pci_dev = mdev->pci_dev;
int err, common, isr, notify, device;
u32 notify_length;
u32 notify_offset;
check_offsets();
mdev->pci_dev = pci_dev;
/* We only own devices >= 0x1000 and <= 0x107f: leave the rest. */
if (pci_dev->device < 0x1000 || pci_dev->device > 0x107f)
return -ENODEV;
if (pci_dev->device < 0x1040) {
/* Transitional devices: use the PCI subsystem device id as
* virtio device id, same as legacy driver always did.
*/
mdev->id.device = pci_dev->subsystem_device;
} else {
/* Modern devices: simply use PCI device id, but start from 0x1040. */
mdev->id.device = pci_dev->device - 0x1040;
}
mdev->id.vendor = pci_dev->subsystem_vendor;
/* check for a common config: if not, use legacy mode (bar 0). */
common = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG,
IORESOURCE_IO | IORESOURCE_MEM,
&mdev->modern_bars);
if (!common) {
dev_info(&pci_dev->dev,
"virtio_pci: leaving for legacy driver\n");
return -ENODEV;
}
/* If common is there, these should be too... */
isr = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_ISR_CFG,
IORESOURCE_IO | IORESOURCE_MEM,
&mdev->modern_bars);
notify = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG,
IORESOURCE_IO | IORESOURCE_MEM,
&mdev->modern_bars);
if (!isr || !notify) {
dev_err(&pci_dev->dev,
"virtio_pci: missing capabilities %i/%i/%i\n",
common, isr, notify);
return -EINVAL;
}
err = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(64));
if (err)
err = dma_set_mask_and_coherent(&pci_dev->dev,
DMA_BIT_MASK(32));
if (err)
dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
/* Device capability is only mandatory for devices that have
* device-specific configuration.
*/
device = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_DEVICE_CFG,
IORESOURCE_IO | IORESOURCE_MEM,
&mdev->modern_bars);
err = pci_request_selected_regions(pci_dev, mdev->modern_bars,
"virtio-pci-modern");
if (err)
return err;
err = -EINVAL;
mdev->common = map_capability(pci_dev, common,
sizeof(struct virtio_pci_common_cfg), 4,
0, sizeof(struct virtio_pci_common_cfg),
NULL);
if (!mdev->common)
goto err_map_common;
mdev->isr = map_capability(pci_dev, isr, sizeof(u8), 1,
0, 1,
NULL);
if (!mdev->isr)
goto err_map_isr;
/* Read notify_off_multiplier from config space. */
pci_read_config_dword(pci_dev,
notify + offsetof(struct virtio_pci_notify_cap,
notify_off_multiplier),
&mdev->notify_offset_multiplier);
/* Read notify length and offset from config space. */
pci_read_config_dword(pci_dev,
notify + offsetof(struct virtio_pci_notify_cap,
cap.length),
&notify_length);
pci_read_config_dword(pci_dev,
notify + offsetof(struct virtio_pci_notify_cap,
cap.offset),
&notify_offset);
/* We don't know how many VQs we'll map, ahead of the time.
* If notify length is small, map it all now.
* Otherwise, map each VQ individually later.
*/
if ((u64)notify_length + (notify_offset % PAGE_SIZE) <= PAGE_SIZE) {
mdev->notify_base = map_capability(pci_dev, notify, 2, 2,
0, notify_length,
&mdev->notify_len);
if (!mdev->notify_base)
goto err_map_notify;
} else {
mdev->notify_map_cap = notify;
}
/* Again, we don't know how much we should map, but PAGE_SIZE
* is more than enough for all existing devices.
*/
if (device) {
mdev->device = map_capability(pci_dev, device, 0, 4,
0, PAGE_SIZE,
&mdev->device_len);
if (!mdev->device)
goto err_map_device;
}
return 0;
err_map_device:
if (mdev->notify_base)
pci_iounmap(pci_dev, mdev->notify_base);
err_map_notify:
pci_iounmap(pci_dev, mdev->isr);
err_map_isr:
pci_iounmap(pci_dev, mdev->common);
err_map_common:
return err;
}
/* the PCI probing function */
int virtio_pci_modern_probe(struct virtio_pci_device *vp_dev)
{
struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
struct pci_dev *pci_dev = vp_dev->pci_dev;
int err;
mdev->pci_dev = pci_dev;
err = vp_modern_probe(mdev);
if (err)
return err;
if (mdev->device)
vp_dev->vdev.config = &virtio_pci_config_ops;
else
vp_dev->vdev.config = &virtio_pci_config_nodev_ops;
vp_dev->config_vector = vp_config_vector;
vp_dev->setup_vq = setup_vq;
vp_dev->del_vq = del_vq;
vp_dev->isr = mdev->isr;
vp_dev->vdev.id = mdev->id;
return 0;
}
/*
* vp_modern_probe: remove and cleanup the modern virtio pci device
* @mdev: the modern virtio-pci device
*/
static void vp_modern_remove(struct virtio_pci_modern_device *mdev)
{
struct pci_dev *pci_dev = mdev->pci_dev;
if (mdev->device)
pci_iounmap(pci_dev, mdev->device);
if (mdev->notify_base)
pci_iounmap(pci_dev, mdev->notify_base);
pci_iounmap(pci_dev, mdev->isr);
pci_iounmap(pci_dev, mdev->common);
pci_release_selected_regions(pci_dev, mdev->modern_bars);
}
void virtio_pci_modern_remove(struct virtio_pci_device *vp_dev)
{
struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
vp_modern_remove(mdev);
}
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