diff options
Diffstat (limited to 'drivers/virtio')
| -rw-r--r-- | drivers/virtio/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/virtio/virtio_mmio.c | 163 |
2 files changed, 174 insertions, 0 deletions
diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig index 1a61939b85fc..f38b17a86c35 100644 --- a/drivers/virtio/Kconfig +++ b/drivers/virtio/Kconfig @@ -46,4 +46,15 @@ config VIRTIO_BALLOON If unsure, say N. +config VIRTIO_MMIO_CMDLINE_DEVICES + bool "Memory mapped virtio devices parameter parsing" + depends on VIRTIO_MMIO + ---help--- + Allow virtio-mmio devices instantiation via the kernel command line + or module parameters. Be aware that using incorrect parameters (base + address in particular) can crash your system - you have been warned. + See Documentation/kernel-parameters.txt for details. + + If unsure, say 'N'. + endmenu diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c index 01d6dc250d5c..453db0c403d8 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 @@ -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> @@ -449,6 +495,122 @@ 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; + int processed, consumed = 0; + struct platform_device *pdev; + + resources[0].flags = IORESOURCE_MEM; + resources[1].flags = IORESOURCE_IRQ; + + resources[0].end = memparse(device, &str) - 1; + + processed = sscanf(str, "@%lli:%u%n:%d%n", + &base, &resources[1].start, &consumed, + &vm_cmdline_id, &consumed); + + if (processed < 2 || processed > 3 || str[consumed]) + return -EINVAL; + + resources[0].start = base; + resources[0].end += base; + resources[1].end = resources[1].start; + + 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[] = { @@ -475,6 +637,7 @@ 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); |