diff options
Diffstat (limited to 'drivers/virtio/virtio_mmio.c')
| -rw-r--r-- | drivers/virtio/virtio_mmio.c | 215 |
1 files changed, 198 insertions, 17 deletions
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c index 01d6dc250d5..c600ccfd692 100644 --- a/drivers/virtio/virtio_mmio.c +++ b/drivers/virtio/virtio_mmio.c @@ -6,6 +6,50 @@ * 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 @@ -31,7 +75,7 @@ * * 0x050 W QueueNotify Queue notifier * 0x060 R InterruptStatus Interrupt status register - * 0x060 W InterruptACK Interrupt acknowledge register + * 0x064 W InterruptACK Interrupt acknowledge register * 0x070 RW Status Device status register * * 0x100+ RW Device-specific configuration space @@ -42,6 +86,8 @@ * 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> @@ -85,9 +131,6 @@ struct virtio_mmio_vq_info { /* 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; @@ -176,14 +219,14 @@ static void vm_reset(struct virtio_device *vdev) /* Transport interface */ /* the notify function used when creating a virt queue */ -static void vm_notify(struct virtqueue *vq) +static bool 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); + writel(vq->index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY); + return true; } /* Notify all virtqueues on an interrupt. */ @@ -224,6 +267,7 @@ 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); @@ -232,7 +276,7 @@ static void vm_del_vq(struct virtqueue *vq) vring_del_virtqueue(vq); /* Select and deactivate the queue */ - writel(info->queue_index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL); + 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)); @@ -263,6 +307,9 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index, 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); @@ -278,7 +325,6 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index, 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 @@ -286,11 +332,21 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index, * 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)); - /* Already smallest possible allocation? */ - if (size <= VIRTIO_MMIO_VRING_ALIGN * 2) { + /* Did the last iter shrink the queue below minimum size? */ + if (size < VIRTIO_MMIO_VRING_ALIGN * 2) { err = -ENOMEM; goto error_alloc_pages; } @@ -310,7 +366,7 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN); /* Create the vring */ - vq = vring_new_virtqueue(info->num, VIRTIO_MMIO_VRING_ALIGN, vdev, + vq = vring_new_virtqueue(index, info->num, VIRTIO_MMIO_VRING_ALIGN, vdev, true, info->queue, vm_notify, callback, name); if (!vq) { err = -ENOMEM; @@ -368,7 +424,7 @@ static const char *vm_bus_name(struct virtio_device *vdev) return vm_dev->pdev->name; } -static struct virtio_config_ops virtio_mmio_config_ops = { +static const struct virtio_config_ops virtio_mmio_config_ops = { .get = vm_get, .set = vm_set, .get_status = vm_get_status, @@ -385,7 +441,7 @@ static struct virtio_config_ops virtio_mmio_config_ops = { /* Platform device */ -static int __devinit virtio_mmio_probe(struct platform_device *pdev) +static int virtio_mmio_probe(struct platform_device *pdev) { struct virtio_mmio_device *vm_dev; struct resource *mem; @@ -415,7 +471,7 @@ static int __devinit virtio_mmio_probe(struct platform_device *pdev) /* Check magic value */ magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE); - if (memcmp(&magic, "virt", 4) != 0) { + if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) { dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic); return -ENODEV; } @@ -438,7 +494,7 @@ static int __devinit virtio_mmio_probe(struct platform_device *pdev) return register_virtio_device(&vm_dev->vdev); } -static int __devexit virtio_mmio_remove(struct platform_device *pdev) +static int virtio_mmio_remove(struct platform_device *pdev) { struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev); @@ -449,6 +505,130 @@ static int __devexit virtio_mmio_remove(struct platform_device *pdev) +/* 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[] = { @@ -459,7 +639,7 @@ MODULE_DEVICE_TABLE(of, virtio_mmio_match); static struct platform_driver virtio_mmio_driver = { .probe = virtio_mmio_probe, - .remove = __devexit_p(virtio_mmio_remove), + .remove = virtio_mmio_remove, .driver = { .name = "virtio-mmio", .owner = THIS_MODULE, @@ -475,6 +655,7 @@ static int __init virtio_mmio_init(void) static void __exit virtio_mmio_exit(void) { platform_driver_unregister(&virtio_mmio_driver); + vm_unregister_cmdline_devices(); } module_init(virtio_mmio_init); |