486 lines
13 KiB
C
486 lines
13 KiB
C
/*
|
|
* Virtio memory mapped device driver
|
|
*
|
|
* Copyright 2011, ARM Ltd.
|
|
*
|
|
* This module allows virtio devices to be used over a virtual, memory mapped
|
|
* platform device.
|
|
*
|
|
* Registers layout (all 32-bit wide):
|
|
*
|
|
* offset d. name description
|
|
* ------ -- ---------------- -----------------
|
|
*
|
|
* 0x000 R MagicValue Magic value "virt"
|
|
* 0x004 R Version Device version (current max. 1)
|
|
* 0x008 R DeviceID Virtio device ID
|
|
* 0x00c R VendorID Virtio vendor ID
|
|
*
|
|
* 0x010 R HostFeatures Features supported by the host
|
|
* 0x014 W HostFeaturesSel Set of host features to access via HostFeatures
|
|
*
|
|
* 0x020 W GuestFeatures Features activated by the guest
|
|
* 0x024 W GuestFeaturesSel Set of activated features to set via GuestFeatures
|
|
* 0x028 W GuestPageSize Size of guest's memory page in bytes
|
|
*
|
|
* 0x030 W QueueSel Queue selector
|
|
* 0x034 R QueueNumMax Maximum size of the currently selected queue
|
|
* 0x038 W QueueNum Queue size for the currently selected queue
|
|
* 0x03c W QueueAlign Used Ring alignment for the current queue
|
|
* 0x040 RW QueuePFN PFN for the currently selected queue
|
|
*
|
|
* 0x050 W QueueNotify Queue notifier
|
|
* 0x060 R InterruptStatus Interrupt status register
|
|
* 0x060 W InterruptACK Interrupt acknowledge register
|
|
* 0x070 RW Status Device status register
|
|
*
|
|
* 0x100+ RW Device-specific configuration space
|
|
*
|
|
* Based on Virtio PCI driver by Anthony Liguori, copyright IBM Corp. 2007
|
|
*
|
|
* This work is licensed under the terms of the GNU GPL, version 2 or later.
|
|
* See the COPYING file in the top-level directory.
|
|
*/
|
|
|
|
#include <linux/highmem.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/io.h>
|
|
#include <linux/list.h>
|
|
#include <linux/module.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/virtio.h>
|
|
#include <linux/virtio_config.h>
|
|
#include <linux/virtio_mmio.h>
|
|
#include <linux/virtio_ring.h>
|
|
|
|
|
|
|
|
/* The alignment to use between consumer and producer parts of vring.
|
|
* Currently hardcoded to the page size. */
|
|
#define VIRTIO_MMIO_VRING_ALIGN PAGE_SIZE
|
|
|
|
|
|
|
|
#define to_virtio_mmio_device(_plat_dev) \
|
|
container_of(_plat_dev, struct virtio_mmio_device, vdev)
|
|
|
|
struct virtio_mmio_device {
|
|
struct virtio_device vdev;
|
|
struct platform_device *pdev;
|
|
|
|
void __iomem *base;
|
|
unsigned long version;
|
|
|
|
/* a list of queues so we can dispatch IRQs */
|
|
spinlock_t lock;
|
|
struct list_head virtqueues;
|
|
};
|
|
|
|
struct virtio_mmio_vq_info {
|
|
/* the actual virtqueue */
|
|
struct virtqueue *vq;
|
|
|
|
/* the number of entries in the queue */
|
|
unsigned int num;
|
|
|
|
/* the index of the queue */
|
|
int queue_index;
|
|
|
|
/* the virtual address of the ring queue */
|
|
void *queue;
|
|
|
|
/* the list node for the virtqueues list */
|
|
struct list_head node;
|
|
};
|
|
|
|
|
|
|
|
/* Configuration interface */
|
|
|
|
static u32 vm_get_features(struct virtio_device *vdev)
|
|
{
|
|
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
|
|
|
|
/* TODO: Features > 32 bits */
|
|
writel(0, vm_dev->base + VIRTIO_MMIO_HOST_FEATURES_SEL);
|
|
|
|
return readl(vm_dev->base + VIRTIO_MMIO_HOST_FEATURES);
|
|
}
|
|
|
|
static void vm_finalize_features(struct virtio_device *vdev)
|
|
{
|
|
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
|
|
int i;
|
|
|
|
/* Give virtio_ring a chance to accept features. */
|
|
vring_transport_features(vdev);
|
|
|
|
for (i = 0; i < ARRAY_SIZE(vdev->features); i++) {
|
|
writel(i, vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES_SEL);
|
|
writel(vdev->features[i],
|
|
vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES);
|
|
}
|
|
}
|
|
|
|
static void vm_get(struct virtio_device *vdev, unsigned offset,
|
|
void *buf, unsigned len)
|
|
{
|
|
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
|
|
u8 *ptr = buf;
|
|
int i;
|
|
|
|
for (i = 0; i < len; i++)
|
|
ptr[i] = readb(vm_dev->base + VIRTIO_MMIO_CONFIG + offset + i);
|
|
}
|
|
|
|
static void vm_set(struct virtio_device *vdev, unsigned offset,
|
|
const void *buf, unsigned len)
|
|
{
|
|
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
|
|
const u8 *ptr = buf;
|
|
int i;
|
|
|
|
for (i = 0; i < len; i++)
|
|
writeb(ptr[i], vm_dev->base + VIRTIO_MMIO_CONFIG + offset + i);
|
|
}
|
|
|
|
static u8 vm_get_status(struct virtio_device *vdev)
|
|
{
|
|
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
|
|
|
|
return readl(vm_dev->base + VIRTIO_MMIO_STATUS) & 0xff;
|
|
}
|
|
|
|
static void vm_set_status(struct virtio_device *vdev, u8 status)
|
|
{
|
|
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
|
|
|
|
/* We should never be setting status to 0. */
|
|
BUG_ON(status == 0);
|
|
|
|
writel(status, vm_dev->base + VIRTIO_MMIO_STATUS);
|
|
}
|
|
|
|
static void vm_reset(struct virtio_device *vdev)
|
|
{
|
|
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
|
|
|
|
/* 0 status means a reset. */
|
|
writel(0, vm_dev->base + VIRTIO_MMIO_STATUS);
|
|
}
|
|
|
|
|
|
|
|
/* Transport interface */
|
|
|
|
/* the notify function used when creating a virt queue */
|
|
static void vm_notify(struct virtqueue *vq)
|
|
{
|
|
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
|
|
struct virtio_mmio_vq_info *info = vq->priv;
|
|
|
|
/* We write the queue's selector into the notification register to
|
|
* signal the other end */
|
|
writel(info->queue_index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY);
|
|
}
|
|
|
|
/* Notify all virtqueues on an interrupt. */
|
|
static irqreturn_t vm_interrupt(int irq, void *opaque)
|
|
{
|
|
struct virtio_mmio_device *vm_dev = opaque;
|
|
struct virtio_mmio_vq_info *info;
|
|
struct virtio_driver *vdrv = container_of(vm_dev->vdev.dev.driver,
|
|
struct virtio_driver, driver);
|
|
unsigned long status;
|
|
unsigned long flags;
|
|
irqreturn_t ret = IRQ_NONE;
|
|
|
|
/* Read and acknowledge interrupts */
|
|
status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS);
|
|
writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK);
|
|
|
|
if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)
|
|
&& vdrv && vdrv->config_changed) {
|
|
vdrv->config_changed(&vm_dev->vdev);
|
|
ret = IRQ_HANDLED;
|
|
}
|
|
|
|
if (likely(status & VIRTIO_MMIO_INT_VRING)) {
|
|
spin_lock_irqsave(&vm_dev->lock, flags);
|
|
list_for_each_entry(info, &vm_dev->virtqueues, node)
|
|
ret |= vring_interrupt(irq, info->vq);
|
|
spin_unlock_irqrestore(&vm_dev->lock, flags);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
|
|
|
|
static void vm_del_vq(struct virtqueue *vq)
|
|
{
|
|
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
|
|
struct virtio_mmio_vq_info *info = vq->priv;
|
|
unsigned long flags, size;
|
|
|
|
spin_lock_irqsave(&vm_dev->lock, flags);
|
|
list_del(&info->node);
|
|
spin_unlock_irqrestore(&vm_dev->lock, flags);
|
|
|
|
vring_del_virtqueue(vq);
|
|
|
|
/* Select and deactivate the queue */
|
|
writel(info->queue_index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
|
|
writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
|
|
|
|
size = PAGE_ALIGN(vring_size(info->num, VIRTIO_MMIO_VRING_ALIGN));
|
|
free_pages_exact(info->queue, size);
|
|
kfree(info);
|
|
}
|
|
|
|
static void vm_del_vqs(struct virtio_device *vdev)
|
|
{
|
|
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
|
|
struct virtqueue *vq, *n;
|
|
|
|
list_for_each_entry_safe(vq, n, &vdev->vqs, list)
|
|
vm_del_vq(vq);
|
|
|
|
free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev);
|
|
}
|
|
|
|
|
|
|
|
static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index,
|
|
void (*callback)(struct virtqueue *vq),
|
|
const char *name)
|
|
{
|
|
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
|
|
struct virtio_mmio_vq_info *info;
|
|
struct virtqueue *vq;
|
|
unsigned long flags, size;
|
|
int err;
|
|
|
|
/* Select the queue we're interested in */
|
|
writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
|
|
|
|
/* Queue shouldn't already be set up. */
|
|
if (readl(vm_dev->base + VIRTIO_MMIO_QUEUE_PFN)) {
|
|
err = -ENOENT;
|
|
goto error_available;
|
|
}
|
|
|
|
/* Allocate and fill out our active queue description */
|
|
info = kmalloc(sizeof(*info), GFP_KERNEL);
|
|
if (!info) {
|
|
err = -ENOMEM;
|
|
goto error_kmalloc;
|
|
}
|
|
info->queue_index = index;
|
|
|
|
/* Allocate pages for the queue - start with a queue as big as
|
|
* possible (limited by maximum size allowed by device), drop down
|
|
* to a minimal size, just big enough to fit descriptor table
|
|
* and two rings (which makes it "alignment_size * 2")
|
|
*/
|
|
info->num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX);
|
|
while (1) {
|
|
size = PAGE_ALIGN(vring_size(info->num,
|
|
VIRTIO_MMIO_VRING_ALIGN));
|
|
/* Already smallest possible allocation? */
|
|
if (size <= VIRTIO_MMIO_VRING_ALIGN * 2) {
|
|
err = -ENOMEM;
|
|
goto error_alloc_pages;
|
|
}
|
|
|
|
info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
|
|
if (info->queue)
|
|
break;
|
|
|
|
info->num /= 2;
|
|
}
|
|
|
|
/* Activate the queue */
|
|
writel(info->num, vm_dev->base + VIRTIO_MMIO_QUEUE_NUM);
|
|
writel(VIRTIO_MMIO_VRING_ALIGN,
|
|
vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN);
|
|
writel(virt_to_phys(info->queue) >> PAGE_SHIFT,
|
|
vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
|
|
|
|
/* Create the vring */
|
|
vq = vring_new_virtqueue(info->num, VIRTIO_MMIO_VRING_ALIGN,
|
|
vdev, info->queue, vm_notify, callback, name);
|
|
if (!vq) {
|
|
err = -ENOMEM;
|
|
goto error_new_virtqueue;
|
|
}
|
|
|
|
vq->priv = info;
|
|
info->vq = vq;
|
|
|
|
spin_lock_irqsave(&vm_dev->lock, flags);
|
|
list_add(&info->node, &vm_dev->virtqueues);
|
|
spin_unlock_irqrestore(&vm_dev->lock, flags);
|
|
|
|
return vq;
|
|
|
|
error_new_virtqueue:
|
|
writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
|
|
free_pages_exact(info->queue, size);
|
|
error_alloc_pages:
|
|
kfree(info);
|
|
error_kmalloc:
|
|
error_available:
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
static int vm_find_vqs(struct virtio_device *vdev, unsigned nvqs,
|
|
struct virtqueue *vqs[],
|
|
vq_callback_t *callbacks[],
|
|
const char *names[])
|
|
{
|
|
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
|
|
unsigned int irq = platform_get_irq(vm_dev->pdev, 0);
|
|
int i, err;
|
|
|
|
err = request_irq(irq, vm_interrupt, IRQF_SHARED,
|
|
dev_name(&vdev->dev), vm_dev);
|
|
if (err)
|
|
return err;
|
|
|
|
for (i = 0; i < nvqs; ++i) {
|
|
vqs[i] = vm_setup_vq(vdev, i, callbacks[i], names[i]);
|
|
if (IS_ERR(vqs[i])) {
|
|
vm_del_vqs(vdev);
|
|
return PTR_ERR(vqs[i]);
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const char *vm_bus_name(struct virtio_device *vdev)
|
|
{
|
|
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
|
|
|
|
return vm_dev->pdev->name;
|
|
}
|
|
|
|
static struct virtio_config_ops virtio_mmio_config_ops = {
|
|
.get = vm_get,
|
|
.set = vm_set,
|
|
.get_status = vm_get_status,
|
|
.set_status = vm_set_status,
|
|
.reset = vm_reset,
|
|
.find_vqs = vm_find_vqs,
|
|
.del_vqs = vm_del_vqs,
|
|
.get_features = vm_get_features,
|
|
.finalize_features = vm_finalize_features,
|
|
.bus_name = vm_bus_name,
|
|
};
|
|
|
|
|
|
|
|
/* Platform device */
|
|
|
|
static int __devinit virtio_mmio_probe(struct platform_device *pdev)
|
|
{
|
|
struct virtio_mmio_device *vm_dev;
|
|
struct resource *mem;
|
|
unsigned long magic;
|
|
|
|
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
if (!mem)
|
|
return -EINVAL;
|
|
|
|
if (!devm_request_mem_region(&pdev->dev, mem->start,
|
|
resource_size(mem), pdev->name))
|
|
return -EBUSY;
|
|
|
|
vm_dev = devm_kzalloc(&pdev->dev, sizeof(*vm_dev), GFP_KERNEL);
|
|
if (!vm_dev)
|
|
return -ENOMEM;
|
|
|
|
vm_dev->vdev.dev.parent = &pdev->dev;
|
|
vm_dev->vdev.config = &virtio_mmio_config_ops;
|
|
vm_dev->pdev = pdev;
|
|
INIT_LIST_HEAD(&vm_dev->virtqueues);
|
|
spin_lock_init(&vm_dev->lock);
|
|
|
|
vm_dev->base = devm_ioremap(&pdev->dev, mem->start, resource_size(mem));
|
|
if (vm_dev->base == NULL)
|
|
return -EFAULT;
|
|
|
|
/* Check magic value */
|
|
magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE);
|
|
if (memcmp(&magic, "virt", 4) != 0) {
|
|
dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic);
|
|
return -ENODEV;
|
|
}
|
|
|
|
/* Check device version */
|
|
vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION);
|
|
if (vm_dev->version != 1) {
|
|
dev_err(&pdev->dev, "Version %ld not supported!\n",
|
|
vm_dev->version);
|
|
return -ENXIO;
|
|
}
|
|
|
|
vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID);
|
|
vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID);
|
|
|
|
writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
|
|
|
|
platform_set_drvdata(pdev, vm_dev);
|
|
|
|
return register_virtio_device(&vm_dev->vdev);
|
|
}
|
|
|
|
static int __devexit virtio_mmio_remove(struct platform_device *pdev)
|
|
{
|
|
struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev);
|
|
|
|
unregister_virtio_device(&vm_dev->vdev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
|
|
/* Platform driver */
|
|
|
|
static struct of_device_id virtio_mmio_match[] = {
|
|
{ .compatible = "virtio,mmio", },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, virtio_mmio_match);
|
|
|
|
static struct platform_driver virtio_mmio_driver = {
|
|
.probe = virtio_mmio_probe,
|
|
.remove = __devexit_p(virtio_mmio_remove),
|
|
.driver = {
|
|
.name = "virtio-mmio",
|
|
.owner = THIS_MODULE,
|
|
.of_match_table = virtio_mmio_match,
|
|
},
|
|
};
|
|
|
|
static int __init virtio_mmio_init(void)
|
|
{
|
|
return platform_driver_register(&virtio_mmio_driver);
|
|
}
|
|
|
|
static void __exit virtio_mmio_exit(void)
|
|
{
|
|
platform_driver_unregister(&virtio_mmio_driver);
|
|
}
|
|
|
|
module_init(virtio_mmio_init);
|
|
module_exit(virtio_mmio_exit);
|
|
|
|
MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
|
|
MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices");
|
|
MODULE_LICENSE("GPL");
|