Re: [PATCH 2/2] virtio-mmio: Devices parameter parsing
From: Sasha Levin
Date: Mon Apr 09 2012 - 12:32:27 EST
Ping? Was this patch forgotten?
On Mon, Dec 12, 2011 at 6:57 PM, Pawel Moll <pawel.moll@xxxxxxx> wrote:
> This patch adds an option to instantiate guest virtio-mmio devices
> basing on a kernel command line (or module) parameter, for example:
>
> virtio_mmio.devices=0x100@0x100b0000:48
>
> Signed-off-by: Pawel Moll <pawel.moll@xxxxxxx>
> ---
> Documentation/kernel-parameters.txt | 17 ++++
> drivers/virtio/Kconfig | 11 +++
> drivers/virtio/virtio_mmio.c | 163 +++++++++++++++++++++++++++++++++++
> 3 files changed, 191 insertions(+), 0 deletions(-)
>
> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
> index a0c5c5f..c155d13 100644
> --- a/Documentation/kernel-parameters.txt
> +++ b/Documentation/kernel-parameters.txt
> @@ -110,6 +110,7 @@ parameter is applicable:
> USB USB support is enabled.
> USBHID USB Human Interface Device support is enabled.
> V4L Video For Linux support is enabled.
> + VMMIO Driver for memory mapped virtio devices is enabled.
> VGA The VGA console has been enabled.
> VT Virtual terminal support is enabled.
> WDT Watchdog support is enabled.
> @@ -2720,6 +2721,22 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
> video= [FB] Frame buffer configuration
> See Documentation/fb/modedb.txt.
>
> + virtio_mmio.device=
> + [VMMIO] Memory mapped virtio (platform) device.
> +
> + <size>@<baseaddr>:<irq>[:<id>]
> + where:
> + <size> := size (can use standard suffixes
> + like K, M and G)
> + <baseaddr> := physical base address
> + <irq> := interrupt number (as passed to
> + request_irq())
> + <id> := (optional) platform device id
> + example:
> + virtio_mmio.device=1K@0x100b0000:48:7
> +
> + Can be used multiple times for multiple devices.
> +
> vga= [BOOT,X86-32] Select a particular video mode
> See Documentation/x86/boot.txt and
> Documentation/svga.txt.
> diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
> index 1a61939..f38b17a 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 7317dc2..eab0007 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>
> @@ -443,6 +489,122 @@ 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[] = {
> @@ -469,6 +631,7 @@ 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);
> --
> 1.7.5.4
>
>
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