| /* |
| * Virtio memory mapped device driver |
| * |
| * Copyright 2011, ARM Ltd. |
| * |
| * This module allows virtio devices to be used over a virtual, memory mapped |
| * platform device. |
| * |
| * The guest device(s) may be instantiated in one of three equivalent ways: |
| * |
| * 1. Static platform device in board's code, eg.: |
| * |
| * static struct platform_device v2m_virtio_device = { |
| * .name = "virtio-mmio", |
| * .id = -1, |
| * .num_resources = 2, |
| * .resource = (struct resource []) { |
| * { |
| * .start = 0x1001e000, |
| * .end = 0x1001e0ff, |
| * .flags = IORESOURCE_MEM, |
| * }, { |
| * .start = 42 + 32, |
| * .end = 42 + 32, |
| * .flags = IORESOURCE_IRQ, |
| * }, |
| * } |
| * }; |
| * |
| * 2. Device Tree node, eg.: |
| * |
| * virtio_block@1e000 { |
| * compatible = "virtio,mmio"; |
| * reg = <0x1e000 0x100>; |
| * interrupts = <42>; |
| * } |
| * |
| * 3. Kernel module (or command line) parameter. Can be used more than once - |
| * one device will be created for each one. Syntax: |
| * |
| * [virtio_mmio.]device=<size>@<baseaddr>:<irq>[:<id>] |
| * where: |
| * <size> := size (can use standard suffixes like K, M or G) |
| * <baseaddr> := physical base address |
| * <irq> := interrupt number (as passed to request_irq()) |
| * <id> := (optional) platform device id |
| * eg.: |
| * virtio_mmio.device=0x100@0x100b0000:48 \ |
| * virtio_mmio.device=1K@0x1001e000:74 |
| * |
| * |
| * |
| * 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 |
| * 0x064 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. |
| */ |
| |
| #define pr_fmt(fmt) "virtio-mmio: " fmt |
| |
| #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 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 bool vm_notify(struct virtqueue *vq) |
| { |
| struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); |
| |
| /* We write the queue's selector into the notification register to |
| * signal the other end */ |
| writel(vq->index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY); |
| return true; |
| } |
| |
| /* 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; |
| 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)) { |
| virtio_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; |
| unsigned int index = vq->index; |
| |
| 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(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; |
| |
| if (!name) |
| return NULL; |
| |
| /* 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; |
| } |
| |
| /* 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); |
| |
| /* If the device reports a 0 entry queue, we won't be able to |
| * use it to perform I/O, and vring_new_virtqueue() can't create |
| * empty queues anyway, so don't bother to set up the device. |
| */ |
| if (info->num == 0) { |
| err = -ENOENT; |
| goto error_alloc_pages; |
| } |
| |
| while (1) { |
| size = PAGE_ALIGN(vring_size(info->num, |
| VIRTIO_MMIO_VRING_ALIGN)); |
| /* Did the last iter shrink the queue below minimum size? */ |
| 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(index, info->num, VIRTIO_MMIO_VRING_ALIGN, vdev, |
| true, 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 const 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 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 (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) { |
| 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 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; |
| } |
| |
| |
| |
| /* Devices list parameter */ |
| |
| #if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES) |
| |
| static struct device vm_cmdline_parent = { |
| .init_name = "virtio-mmio-cmdline", |
| }; |
| |
| static int vm_cmdline_parent_registered; |
| static int vm_cmdline_id; |
| |
| static int vm_cmdline_set(const char *device, |
| const struct kernel_param *kp) |
| { |
| int err; |
| struct resource resources[2] = {}; |
| char *str; |
| long long int base, size; |
| unsigned int irq; |
| int processed, consumed = 0; |
| struct platform_device *pdev; |
| |
| /* Consume "size" part of the command line parameter */ |
| size = memparse(device, &str); |
| |
| /* Get "@<base>:<irq>[:<id>]" chunks */ |
| processed = sscanf(str, "@%lli:%u%n:%d%n", |
| &base, &irq, &consumed, |
| &vm_cmdline_id, &consumed); |
| |
| /* |
| * sscanf() must processes at least 2 chunks; also there |
| * must be no extra characters after the last chunk, so |
| * str[consumed] must be '\0' |
| */ |
| if (processed < 2 || str[consumed]) |
| return -EINVAL; |
| |
| resources[0].flags = IORESOURCE_MEM; |
| resources[0].start = base; |
| resources[0].end = base + size - 1; |
| |
| resources[1].flags = IORESOURCE_IRQ; |
| resources[1].start = resources[1].end = irq; |
| |
| if (!vm_cmdline_parent_registered) { |
| err = device_register(&vm_cmdline_parent); |
| if (err) { |
| pr_err("Failed to register parent device!\n"); |
| return err; |
| } |
| vm_cmdline_parent_registered = 1; |
| } |
| |
| pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n", |
| vm_cmdline_id, |
| (unsigned long long)resources[0].start, |
| (unsigned long long)resources[0].end, |
| (int)resources[1].start); |
| |
| pdev = platform_device_register_resndata(&vm_cmdline_parent, |
| "virtio-mmio", vm_cmdline_id++, |
| resources, ARRAY_SIZE(resources), NULL, 0); |
| if (IS_ERR(pdev)) |
| return PTR_ERR(pdev); |
| |
| return 0; |
| } |
| |
| static int vm_cmdline_get_device(struct device *dev, void *data) |
| { |
| char *buffer = data; |
| unsigned int len = strlen(buffer); |
| struct platform_device *pdev = to_platform_device(dev); |
| |
| snprintf(buffer + len, PAGE_SIZE - len, "0x%llx@0x%llx:%llu:%d\n", |
| pdev->resource[0].end - pdev->resource[0].start + 1ULL, |
| (unsigned long long)pdev->resource[0].start, |
| (unsigned long long)pdev->resource[1].start, |
| pdev->id); |
| return 0; |
| } |
| |
| static int vm_cmdline_get(char *buffer, const struct kernel_param *kp) |
| { |
| buffer[0] = '\0'; |
| device_for_each_child(&vm_cmdline_parent, buffer, |
| vm_cmdline_get_device); |
| return strlen(buffer) + 1; |
| } |
| |
| static struct kernel_param_ops vm_cmdline_param_ops = { |
| .set = vm_cmdline_set, |
| .get = vm_cmdline_get, |
| }; |
| |
| device_param_cb(device, &vm_cmdline_param_ops, NULL, S_IRUSR); |
| |
| static int vm_unregister_cmdline_device(struct device *dev, |
| void *data) |
| { |
| platform_device_unregister(to_platform_device(dev)); |
| |
| return 0; |
| } |
| |
| static void vm_unregister_cmdline_devices(void) |
| { |
| if (vm_cmdline_parent_registered) { |
| device_for_each_child(&vm_cmdline_parent, NULL, |
| vm_unregister_cmdline_device); |
| device_unregister(&vm_cmdline_parent); |
| vm_cmdline_parent_registered = 0; |
| } |
| } |
| |
| #else |
| |
| static void vm_unregister_cmdline_devices(void) |
| { |
| } |
| |
| #endif |
| |
| /* 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 = 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); |
| vm_unregister_cmdline_devices(); |
| } |
| |
| 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"); |