virtio_ivshmem.c
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// SPDX-License-Identifier: GPL-2.0-only
/*
* Virtio over ivshmem front-end device driver
*
* Copyright (c) Siemens AG, 2019
*/
#include <linux/delay.h>
#include <linux/dma-map-ops.h>
#include <linux/ivshmem.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/pci.h>
#include <linux/virtio.h>
#include <linux/virtio_config.h>
#include <linux/virtio_ring.h>
#define DRV_NAME "virtio-ivshmem"
#define VIRTIO_IVSHMEM_PREFERRED_ALLOC_CHUNKS 4096
#define VIRTIO_STATE_READY cpu_to_le32(1)
struct virtio_ivshmem_header {
__le32 revision;
__le32 size;
__le32 write_transaction;
__le32 device_features;
__le32 device_features_sel;
__le32 driver_features;
__le32 driver_features_sel;
__le32 queue_sel;
__le16 queue_size;
__le16 queue_device_vector;
__le16 queue_driver_vector;
__le16 queue_enable;
__le64 queue_desc;
__le64 queue_driver;
__le64 queue_device;
__u8 config_event;
__u8 queue_event;
__u8 __reserved[2];
__le32 device_status;
__le32 config_generation;
__u8 config[];
};
#define VI_REG_OFFSET(reg) offsetof(struct virtio_ivshmem_header, reg)
struct virtio_ivshmem_device {
struct virtio_device vdev;
struct pci_dev *pci_dev;
struct ivshm_regs __iomem *ivshm_regs;
unsigned int num_vectors;
bool per_vq_vector;
char *config_irq_name;
char *queues_irq_name;
u32 peer_id;
u32 *peer_state;
void *shmem;
resource_size_t shmem_sz;
struct virtio_ivshmem_header *virtio_header;
spinlock_t alloc_lock;
unsigned long *alloc_bitmap;
unsigned int alloc_shift;
void **map_src_addr;
/* a list of queues so we can dispatch IRQs */
spinlock_t virtqueues_lock;
struct list_head virtqueues;
};
struct virtio_ivshmem_vq_info {
/* the actual virtqueue */
struct virtqueue *vq;
/* vector to use for signaling the device */
unsigned int device_vector;
/* vector used by the device for signaling the driver */
unsigned int driver_vector;
char *irq_name;
/* the list node for the virtqueues list */
struct list_head node;
};
static inline unsigned int get_custom_order(unsigned long size,
unsigned int shift)
{
size--;
size >>= shift;
#if BITS_PER_LONG == 32
return fls(size);
#else
return fls64(size);
#endif
}
static inline struct virtio_ivshmem_device *
to_virtio_ivshmem_device(struct virtio_device *vdev)
{
return container_of(vdev, struct virtio_ivshmem_device, vdev);
}
static bool vi_synchronize_reg_write(struct virtio_ivshmem_device *vi_dev)
{
while (READ_ONCE(vi_dev->virtio_header->write_transaction)) {
if (READ_ONCE(*vi_dev->peer_state) != VIRTIO_STATE_READY) {
dev_err_ratelimited(&vi_dev->pci_dev->dev,
"backend failed!");
return false;
}
cpu_relax();
}
return true;
}
static bool vi_reg_write(struct virtio_ivshmem_device *vi_dev, unsigned int reg,
u64 value, unsigned int size)
{
u8 *reg_area = (u8 *)vi_dev->virtio_header;
if (!vi_synchronize_reg_write(vi_dev))
return false;
if (size == 1)
*(u8 *)(reg_area + reg) = (u8)value;
else if (size == 2)
*(u16 *)(reg_area + reg) = cpu_to_le16((u16)value);
else if (size == 4)
*(u32 *)(reg_area + reg) = cpu_to_le32((u32)value);
else if (size == 8)
*(u64 *)(reg_area + reg) = cpu_to_le64(value);
else
BUG();
virt_wmb();
vi_dev->virtio_header->write_transaction = cpu_to_le32(reg);
virt_wmb();
writel((vi_dev->peer_id << 16), &vi_dev->ivshm_regs->doorbell);
return true;
}
static bool vi_reg_write16(struct virtio_ivshmem_device *vi_dev,
unsigned int reg, u32 value)
{
return vi_reg_write(vi_dev, reg, value, 2);
}
static bool vi_reg_write32(struct virtio_ivshmem_device *vi_dev,
unsigned int reg, u32 value)
{
return vi_reg_write(vi_dev, reg, value, 4);
}
static bool vi_reg_write64(struct virtio_ivshmem_device *vi_dev,
unsigned int reg, u64 value)
{
return vi_reg_write(vi_dev, reg, value, 8);
}
static void vi_get(struct virtio_device *vdev, unsigned offset,
void *buf, unsigned len)
{
struct virtio_ivshmem_device *vi_dev = to_virtio_ivshmem_device(vdev);
__le16 w;
__le32 l;
__le64 q;
switch (len) {
case 1:
*(u8 *)buf = *(u8 *)(vi_dev->virtio_header->config + offset);
break;
case 2:
w = *(u16 *)(vi_dev->virtio_header->config + offset);
*(u16 *)buf = le16_to_cpu(w);
break;
case 4:
l = *(u32 *)(vi_dev->virtio_header->config + offset);
*(u32 *)buf = le32_to_cpu(l);
break;
case 8:
q = *(u64 *)(vi_dev->virtio_header->config + offset);
*(u64 *)buf = le64_to_cpu(q);
break;
default:
BUG();
}
}
static void vi_set(struct virtio_device *vdev, unsigned offset,
const void *buf, unsigned len)
{
u64 value;
switch (len) {
case 1:
value = *(u8 *)buf;
break;
case 2:
value = *(u16 *)buf;
break;
case 4:
value = *(u32 *)buf;
break;
case 8:
value = *(u64 *)buf;
break;
default:
BUG();
}
vi_reg_write(to_virtio_ivshmem_device(vdev),
offsetof(struct virtio_ivshmem_header, config) + offset,
value, len);
}
static u32 vi_generation(struct virtio_device *vdev)
{
struct virtio_ivshmem_device *vi_dev = to_virtio_ivshmem_device(vdev);
u32 gen = READ_ONCE(vi_dev->virtio_header->config_generation);
while (gen & 1) {
if (READ_ONCE(*vi_dev->peer_state) != VIRTIO_STATE_READY) {
dev_err_ratelimited(&vi_dev->pci_dev->dev,
"backend failed!");
return 0;
}
cpu_relax();
gen = READ_ONCE(vi_dev->virtio_header->config_generation);
}
return gen;
}
static u8 vi_get_status(struct virtio_device *vdev)
{
struct virtio_ivshmem_device *vi_dev = to_virtio_ivshmem_device(vdev);
return le32_to_cpu(vi_dev->virtio_header->device_status) & 0xff;
}
static void vi_set_status(struct virtio_device *vdev, u8 status)
{
struct virtio_ivshmem_device *vi_dev = to_virtio_ivshmem_device(vdev);
/* We should never be setting status to 0. */
BUG_ON(status == 0);
vi_reg_write32(vi_dev, VI_REG_OFFSET(device_status), status);
}
static void vi_reset(struct virtio_device *vdev)
{
struct virtio_ivshmem_device *vi_dev = to_virtio_ivshmem_device(vdev);
/* 0 status means a reset. */
vi_reg_write32(vi_dev, VI_REG_OFFSET(device_status), 0);
}
static u64 vi_get_features(struct virtio_device *vdev)
{
struct virtio_ivshmem_device *vi_dev = to_virtio_ivshmem_device(vdev);
u64 features;
if (!vi_reg_write32(vi_dev, VI_REG_OFFSET(device_features_sel), 1) ||
!vi_synchronize_reg_write(vi_dev))
return 0;
features = le32_to_cpu(vi_dev->virtio_header->device_features);
features <<= 32;
if (!vi_reg_write32(vi_dev, VI_REG_OFFSET(device_features_sel), 0) ||
!vi_synchronize_reg_write(vi_dev))
return 0;
features |= le32_to_cpu(vi_dev->virtio_header->device_features);
return features;
}
static int vi_finalize_features(struct virtio_device *vdev)
{
struct virtio_ivshmem_device *vi_dev = to_virtio_ivshmem_device(vdev);
/* Give virtio_ring a chance to accept features. */
vring_transport_features(vdev);
if (!__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
dev_err(&vdev->dev,
"virtio: device does not have VIRTIO_F_VERSION_1\n");
return -EINVAL;
}
if (!vi_reg_write32(vi_dev, VI_REG_OFFSET(driver_features_sel), 1) ||
!vi_reg_write32(vi_dev, VI_REG_OFFSET(driver_features),
(u32)(vdev->features >> 32)))
return -ENODEV;
if (!vi_reg_write32(vi_dev, VI_REG_OFFSET(driver_features_sel), 0) ||
!vi_reg_write32(vi_dev, VI_REG_OFFSET(driver_features),
(u32)vdev->features))
return -ENODEV;
return 0;
}
/* the notify function used when creating a virt queue */
static bool vi_notify(struct virtqueue *vq)
{
struct virtio_ivshmem_vq_info *info = vq->priv;
struct virtio_ivshmem_device *vi_dev =
to_virtio_ivshmem_device(vq->vdev);
virt_wmb();
writel((vi_dev->peer_id << 16) | info->device_vector,
&vi_dev->ivshm_regs->doorbell);
return true;
}
static irqreturn_t vi_config_interrupt(int irq, void *opaque)
{
struct virtio_ivshmem_device *vi_dev = opaque;
if (unlikely(READ_ONCE(*vi_dev->peer_state) != VIRTIO_STATE_READY)) {
virtio_break_device(&vi_dev->vdev);
vi_dev->virtio_header->config_event = 0;
vi_dev->virtio_header->queue_event = 0;
dev_err(&vi_dev->pci_dev->dev, "backend failed!");
return IRQ_HANDLED;
}
if (unlikely(READ_ONCE(vi_dev->virtio_header->config_event) & 1)) {
vi_dev->virtio_header->config_event = 0;
virt_wmb();
virtio_config_changed(&vi_dev->vdev);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
static irqreturn_t vi_queues_interrupt(int irq, void *opaque)
{
struct virtio_ivshmem_device *vi_dev = opaque;
struct virtio_ivshmem_vq_info *info;
irqreturn_t ret = IRQ_NONE;
if (likely(READ_ONCE(vi_dev->virtio_header->queue_event) & 1)) {
vi_dev->virtio_header->queue_event = 0;
virt_wmb();
spin_lock(&vi_dev->virtqueues_lock);
list_for_each_entry(info, &vi_dev->virtqueues, node)
ret |= vring_interrupt(irq, info->vq);
spin_unlock(&vi_dev->virtqueues_lock);
}
return ret;
}
static irqreturn_t vi_interrupt(int irq, void *opaque)
{
return vi_config_interrupt(irq, opaque) |
vi_queues_interrupt(irq, opaque);
}
static struct virtqueue *vi_setup_vq(struct virtio_device *vdev,
unsigned int index,
void (*callback)(struct virtqueue *vq),
const char *name, bool ctx,
unsigned int irq_vector)
{
struct virtio_ivshmem_device *vi_dev = to_virtio_ivshmem_device(vdev);
struct virtio_ivshmem_vq_info *info;
struct virtqueue *vq;
unsigned long flags;
unsigned int size;
int irq, err;
/* Select the queue we're interested in */
if (!vi_reg_write32(vi_dev, VI_REG_OFFSET(queue_sel), index) ||
!vi_synchronize_reg_write(vi_dev))
return ERR_PTR(-ENODEV);
/* Queue shouldn't already be set up. */
if (vi_dev->virtio_header->queue_enable)
return ERR_PTR(-ENOENT);
/* Allocate and fill out our active queue description */
info = kzalloc(sizeof(*info), GFP_KERNEL);
if (!info)
return ERR_PTR(-ENOMEM);
size = vi_dev->virtio_header->queue_size;
if (size == 0) {
err = -ENOENT;
goto error_new_virtqueue;
}
info->device_vector = vi_dev->virtio_header->queue_device_vector;
info->driver_vector = irq_vector;
/* Create the vring */
vq = vring_create_virtqueue(index, size, SMP_CACHE_BYTES, vdev, true,
true, ctx, vi_notify, callback, name);
if (!vq) {
err = -ENOMEM;
goto error_new_virtqueue;
}
if (callback && vi_dev->per_vq_vector) {
irq = pci_irq_vector(vi_dev->pci_dev, info->driver_vector);
info->irq_name = kasprintf(GFP_KERNEL, "%s-%s",
dev_name(&vdev->dev), name);
if (!info->irq_name) {
err = -ENOMEM;
goto error_setup_virtqueue;
}
err = request_irq(irq, vring_interrupt, 0, info->irq_name, vq);
if (err)
goto error_setup_virtqueue;
}
/* Activate the queue */
if (!vi_reg_write16(vi_dev, VI_REG_OFFSET(queue_size),
virtqueue_get_vring_size(vq)) ||
!vi_reg_write16(vi_dev, VI_REG_OFFSET(queue_driver_vector),
info->driver_vector) ||
!vi_reg_write64(vi_dev, VI_REG_OFFSET(queue_desc),
virtqueue_get_desc_addr(vq)) ||
!vi_reg_write64(vi_dev, VI_REG_OFFSET(queue_driver),
virtqueue_get_avail_addr(vq)) ||
!vi_reg_write64(vi_dev, VI_REG_OFFSET(queue_device),
virtqueue_get_used_addr(vq)) ||
!vi_reg_write16(vi_dev, VI_REG_OFFSET(queue_enable), 1)) {
err = -ENODEV;
goto error_setup_virtqueue;
}
vq->priv = info;
info->vq = vq;
spin_lock_irqsave(&vi_dev->virtqueues_lock, flags);
list_add(&info->node, &vi_dev->virtqueues);
spin_unlock_irqrestore(&vi_dev->virtqueues_lock, flags);
return vq;
error_setup_virtqueue:
vring_del_virtqueue(vq);
error_new_virtqueue:
vi_reg_write32(vi_dev, VI_REG_OFFSET(queue_enable), 0);
kfree(info);
return ERR_PTR(err);
}
static void vi_del_vq(struct virtqueue *vq)
{
struct virtio_ivshmem_device *vi_dev =
to_virtio_ivshmem_device(vq->vdev);
struct virtio_ivshmem_vq_info *info = vq->priv;
unsigned long flags;
spin_lock_irqsave(&vi_dev->virtqueues_lock, flags);
list_del(&info->node);
spin_unlock_irqrestore(&vi_dev->virtqueues_lock, flags);
/* Select and deactivate the queue */
vi_reg_write32(vi_dev, VI_REG_OFFSET(queue_sel), vq->index);
vi_reg_write32(vi_dev, VI_REG_OFFSET(queue_enable), 0);
vring_del_virtqueue(vq);
if (info->driver_vector) {
free_irq(pci_irq_vector(vi_dev->pci_dev, info->driver_vector),
vq);
kfree(info->irq_name);
}
kfree(info);
}
static void vi_del_vqs(struct virtio_device *vdev)
{
struct virtio_ivshmem_device *vi_dev = to_virtio_ivshmem_device(vdev);
struct virtqueue *vq, *n;
list_for_each_entry_safe(vq, n, &vdev->vqs, list)
vi_del_vq(vq);
free_irq(pci_irq_vector(vi_dev->pci_dev, 0), vi_dev);
if (!vi_dev->per_vq_vector && vi_dev->num_vectors > 1)
free_irq(pci_irq_vector(vi_dev->pci_dev, 1), vi_dev);
pci_free_irq_vectors(vi_dev->pci_dev);
kfree(vi_dev->config_irq_name);
vi_dev->config_irq_name = NULL;
kfree(vi_dev->queues_irq_name);
vi_dev->queues_irq_name = NULL;
}
static int vi_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_ivshmem_device *vi_dev = to_virtio_ivshmem_device(vdev);
unsigned int vq_vector, desired_vectors;
int err, vectors, i, queue_idx = 0;
desired_vectors = 1; /* one for config events */
for (i = 0; i < nvqs; i++)
if (callbacks[i])
desired_vectors++;
vectors = pci_alloc_irq_vectors(vi_dev->pci_dev, desired_vectors,
desired_vectors, PCI_IRQ_MSIX);
if (vectors != desired_vectors) {
vectors = pci_alloc_irq_vectors(vi_dev->pci_dev, 1, 2,
PCI_IRQ_LEGACY | PCI_IRQ_MSIX);
if (vectors < 0)
return vectors;
}
vi_dev->num_vectors = vectors;
vi_dev->per_vq_vector = vectors == desired_vectors;
if (vectors == 1) {
vq_vector = 0;
err = request_irq(pci_irq_vector(vi_dev->pci_dev, 0),
vi_interrupt, IRQF_SHARED,
dev_name(&vdev->dev), vi_dev);
if (err)
goto error_common_irq;
} else {
vq_vector = 1;
vi_dev->config_irq_name = kasprintf(GFP_KERNEL, "%s-config",
dev_name(&vdev->dev));
if (!vi_dev->config_irq_name) {
err = -ENOMEM;
goto error_common_irq;
}
err = request_irq(pci_irq_vector(vi_dev->pci_dev, 0),
vi_config_interrupt, 0,
vi_dev->config_irq_name, vi_dev);
if (err)
goto error_common_irq;
}
if (!vi_dev->per_vq_vector && vectors > 1) {
vi_dev->queues_irq_name = kasprintf(GFP_KERNEL, "%s-virtqueues",
dev_name(&vdev->dev));
if (!vi_dev->queues_irq_name) {
err = -ENOMEM;
goto error_queues_irq;
}
err = request_irq(pci_irq_vector(vi_dev->pci_dev, 1),
vi_queues_interrupt, 0,
vi_dev->queues_irq_name, vi_dev);
if (err)
goto error_queues_irq;
}
for (i = 0; i < nvqs; ++i) {
if (!names[i]) {
vqs[i] = NULL;
continue;
}
vqs[i] = vi_setup_vq(vdev, queue_idx++, callbacks[i], names[i],
ctx ? ctx[i] : false, vq_vector);
if (IS_ERR(vqs[i])) {
vi_del_vqs(vdev);
return PTR_ERR(vqs[i]);
}
if (vi_dev->per_vq_vector)
vq_vector++;
}
writel(IVSHM_INT_ENABLE, &vi_dev->ivshm_regs->int_control);
return 0;
error_queues_irq:
free_irq(pci_irq_vector(vi_dev->pci_dev, 0), vi_dev);
kfree(vi_dev->config_irq_name);
vi_dev->config_irq_name = NULL;
error_common_irq:
kfree(vi_dev->queues_irq_name);
vi_dev->queues_irq_name = NULL;
pci_free_irq_vectors(vi_dev->pci_dev);
return err;
}
static const char *vi_bus_name(struct virtio_device *vdev)
{
struct virtio_ivshmem_device *vi_dev = to_virtio_ivshmem_device(vdev);
return pci_name(vi_dev->pci_dev);
}
static const struct virtio_config_ops virtio_ivshmem_config_ops = {
.get = vi_get,
.set = vi_set,
.generation = vi_generation,
.get_status = vi_get_status,
.set_status = vi_set_status,
.reset = vi_reset,
.find_vqs = vi_find_vqs,
.del_vqs = vi_del_vqs,
.get_features = vi_get_features,
.finalize_features = vi_finalize_features,
.bus_name = vi_bus_name,
};
static void virtio_ivshmem_release_dev(struct device *_d)
{
struct virtio_device *vdev = dev_to_virtio(_d);
struct virtio_ivshmem_device *vi_dev = to_virtio_ivshmem_device(vdev);
devm_kfree(&vi_dev->pci_dev->dev, vi_dev);
}
static u64 get_config_qword(struct pci_dev *pci_dev, unsigned int pos)
{
u32 lo, hi;
pci_read_config_dword(pci_dev, pos, &lo);
pci_read_config_dword(pci_dev, pos + 4, &hi);
return lo | ((u64)hi << 32);
}
static void *vi_dma_alloc(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flag,
unsigned long attrs)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
struct virtio_ivshmem_device *vi_dev = pci_get_drvdata(pci_dev);
int order = get_custom_order(size, vi_dev->alloc_shift);
int chunk = -ENOMEM;
unsigned long flags;
void *addr;
spin_lock_irqsave(&vi_dev->alloc_lock, flags);
chunk = bitmap_find_free_region(vi_dev->alloc_bitmap,
vi_dev->shmem_sz >> vi_dev->alloc_shift,
order);
spin_unlock_irqrestore(&vi_dev->alloc_lock, flags);
if (chunk < 0) {
if (!(attrs & DMA_ATTR_NO_WARN) && printk_ratelimit())
dev_warn(dev,
"shared memory is full (size: %zd bytes)\n",
size);
return NULL;
}
*dma_handle = chunk << vi_dev->alloc_shift;
addr = vi_dev->shmem + *dma_handle;
memset(addr, 0, size);
return addr;
}
static void vi_dma_free(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_handle, unsigned long attrs)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
struct virtio_ivshmem_device *vi_dev = pci_get_drvdata(pci_dev);
int order = get_custom_order(size, vi_dev->alloc_shift);
int chunk = (int)(dma_handle >> vi_dev->alloc_shift);
unsigned long flags;
spin_lock_irqsave(&vi_dev->alloc_lock, flags);
bitmap_release_region(vi_dev->alloc_bitmap, chunk, order);
spin_unlock_irqrestore(&vi_dev->alloc_lock, flags);
}
static dma_addr_t vi_dma_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction dir,
unsigned long attrs)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
struct virtio_ivshmem_device *vi_dev = pci_get_drvdata(pci_dev);
void *buffer, *orig_addr;
dma_addr_t dma_addr;
buffer = vi_dma_alloc(dev, size, &dma_addr, 0, attrs);
if (!buffer)
return DMA_MAPPING_ERROR;
orig_addr = page_address(page) + offset;
vi_dev->map_src_addr[dma_addr >> vi_dev->alloc_shift] = orig_addr;
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL))
memcpy(buffer, orig_addr, size);
return dma_addr;
}
static void vi_dma_unmap_page(struct device *dev, dma_addr_t dma_addr,
size_t size, enum dma_data_direction dir,
unsigned long attrs)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
struct virtio_ivshmem_device *vi_dev = pci_get_drvdata(pci_dev);
void *orig_addr = vi_dev->map_src_addr[dma_addr >> vi_dev->alloc_shift];
void *buffer = vi_dev->shmem + dma_addr;
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL)))
memcpy(orig_addr, buffer, size);
vi_dma_free(dev, size, buffer, dma_addr, attrs);
}
static void
vi_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_addr,
size_t size, enum dma_data_direction dir)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
struct virtio_ivshmem_device *vi_dev = pci_get_drvdata(pci_dev);
void *orig_addr = vi_dev->map_src_addr[dma_addr >> vi_dev->alloc_shift];
void *buffer = vi_dev->shmem + dma_addr;
memcpy(orig_addr, buffer, size);
}
static void
vi_dma_sync_single_for_device(struct device *dev, dma_addr_t dma_addr,
size_t size, enum dma_data_direction dir)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
struct virtio_ivshmem_device *vi_dev = pci_get_drvdata(pci_dev);
void *orig_addr = vi_dev->map_src_addr[dma_addr >> vi_dev->alloc_shift];
void *buffer = vi_dev->shmem + dma_addr;
memcpy(buffer, orig_addr, size);
}
static const struct dma_map_ops virtio_ivshmem_dma_ops = {
.alloc = vi_dma_alloc,
.free = vi_dma_free,
.map_page = vi_dma_map_page,
.unmap_page = vi_dma_unmap_page,
.sync_single_for_cpu = vi_dma_sync_single_for_cpu,
.sync_single_for_device = vi_dma_sync_single_for_device,
};
static int virtio_ivshmem_probe(struct pci_dev *pci_dev,
const struct pci_device_id *pci_id)
{
unsigned int chunks, chunk_size, bitmap_size;
struct virtio_ivshmem_device *vi_dev;
resource_size_t section_sz;
phys_addr_t section_addr;
unsigned int cap_pos;
u32 *state_table;
int vendor_cap;
u32 id, dword;
int ret;
vi_dev = devm_kzalloc(&pci_dev->dev, sizeof(*vi_dev), GFP_KERNEL);
if (!vi_dev)
return -ENOMEM;
pci_set_drvdata(pci_dev, vi_dev);
vi_dev->vdev.dev.parent = &pci_dev->dev;
vi_dev->vdev.dev.release = virtio_ivshmem_release_dev;
vi_dev->vdev.config = &virtio_ivshmem_config_ops;
vi_dev->vdev.id.device = pci_dev->class & IVSHM_PROTO_VIRTIO_DEVID_MASK;
vi_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
vi_dev->pci_dev = pci_dev;
spin_lock_init(&vi_dev->virtqueues_lock);
INIT_LIST_HEAD(&vi_dev->virtqueues);
ret = pcim_enable_device(pci_dev);
if (ret)
return ret;
ret = pcim_iomap_regions(pci_dev, BIT(0), DRV_NAME);
if (ret)
return ret;
vi_dev->ivshm_regs = pcim_iomap_table(pci_dev)[0];
id = readl(&vi_dev->ivshm_regs->id);
if (id > 1) {
dev_err(&pci_dev->dev, "invalid ID %d\n", id);
return -EINVAL;
}
if (readl(&vi_dev->ivshm_regs->max_peers) != 2) {
dev_err(&pci_dev->dev, "number of peers must be 2\n");
return -EINVAL;
}
vi_dev->peer_id = !id;
vendor_cap = pci_find_capability(pci_dev, PCI_CAP_ID_VNDR);
if (vendor_cap < 0) {
dev_err(&pci_dev->dev, "missing vendor capability\n");
return -EINVAL;
}
if (pci_resource_len(pci_dev, 2) > 0) {
section_addr = pci_resource_start(pci_dev, 2);
} else {
cap_pos = vendor_cap + IVSHM_CFG_ADDRESS;
section_addr = get_config_qword(pci_dev, cap_pos);
}
cap_pos = vendor_cap + IVSHM_CFG_STATE_TAB_SZ;
pci_read_config_dword(pci_dev, cap_pos, &dword);
section_sz = dword;
if (!devm_request_mem_region(&pci_dev->dev, section_addr, section_sz,
DRV_NAME))
return -EBUSY;
state_table = devm_memremap(&pci_dev->dev, section_addr, section_sz,
MEMREMAP_WB);
if (!state_table)
return -ENOMEM;
vi_dev->peer_state = &state_table[vi_dev->peer_id];
if (*vi_dev->peer_state != VIRTIO_STATE_READY) {
dev_err(&pci_dev->dev, "backend not ready\n");
return -ENODEV;
}
section_addr += section_sz;
cap_pos = vendor_cap + IVSHM_CFG_RW_SECTION_SZ;
section_sz = get_config_qword(pci_dev, cap_pos);
if (section_sz < 2 * PAGE_SIZE) {
dev_err(&pci_dev->dev, "R/W section too small\n");
return -EINVAL;
}
vi_dev->shmem_sz = section_sz;
vi_dev->shmem = devm_memremap(&pci_dev->dev, section_addr, section_sz,
MEMREMAP_WB);
if (!vi_dev->shmem)
return -ENOMEM;
vi_dev->virtio_header = vi_dev->shmem;
if (vi_dev->virtio_header->revision < 1) {
dev_err(&pci_dev->dev, "invalid virtio-ivshmem revision\n");
return -EINVAL;
}
spin_lock_init(&vi_dev->alloc_lock);
chunk_size = vi_dev->shmem_sz / VIRTIO_IVSHMEM_PREFERRED_ALLOC_CHUNKS;
if (chunk_size < SMP_CACHE_BYTES)
chunk_size = SMP_CACHE_BYTES;
if (chunk_size > PAGE_SIZE)
chunk_size = PAGE_SIZE;
vi_dev->alloc_shift = get_custom_order(chunk_size, 0);
chunks = vi_dev->shmem_sz >> vi_dev->alloc_shift;
bitmap_size = BITS_TO_LONGS(chunks) * sizeof(long);
vi_dev->alloc_bitmap = devm_kzalloc(&pci_dev->dev,
bitmap_size,
GFP_KERNEL);
if (!vi_dev->alloc_bitmap)
return -ENOMEM;
/* mark the header chunks used */
bitmap_set(vi_dev->alloc_bitmap, 0,
1 << get_custom_order(vi_dev->virtio_header->size,
vi_dev->alloc_shift));
vi_dev->map_src_addr = devm_kzalloc(&pci_dev->dev,
chunks * sizeof(void *),
GFP_KERNEL);
if (!vi_dev->map_src_addr)
return -ENOMEM;
set_dma_ops(&pci_dev->dev, &virtio_ivshmem_dma_ops);
pci_set_master(pci_dev);
pci_write_config_byte(pci_dev, vendor_cap + IVSHM_CFG_PRIV_CNTL, 0);
writel(VIRTIO_STATE_READY, &vi_dev->ivshm_regs->state);
ret = register_virtio_device(&vi_dev->vdev);
if (ret) {
dev_err(&pci_dev->dev, "failed to register device\n");
writel(0, &vi_dev->ivshm_regs->state);
put_device(&vi_dev->vdev.dev);
}
return ret;
}
static void virtio_ivshmem_remove(struct pci_dev *pci_dev)
{
struct virtio_ivshmem_device *vi_dev = pci_get_drvdata(pci_dev);
writel(0, &vi_dev->ivshm_regs->state);
writel(0, &vi_dev->ivshm_regs->int_control);
unregister_virtio_device(&vi_dev->vdev);
}
static const struct pci_device_id virtio_ivshmem_id_table[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_SIEMENS, PCI_DEVICE_ID_IVSHMEM),
(PCI_CLASS_OTHERS << 16) | IVSHM_PROTO_VIRTIO_FRONT, 0xffff00 },
{ 0 }
};
MODULE_DEVICE_TABLE(pci, virtio_ivshmem_id_table);
static struct pci_driver virtio_ivshmem_driver = {
.name = DRV_NAME,
.id_table = virtio_ivshmem_id_table,
.probe = virtio_ivshmem_probe,
.remove = virtio_ivshmem_remove,
};
module_pci_driver(virtio_ivshmem_driver);
MODULE_AUTHOR("Jan Kiszka <jan.kiszka@siemens.com>");
MODULE_DESCRIPTION("Driver for ivshmem-based virtio front-end devices");
MODULE_LICENSE("GPL v2");