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SubjectRe: [PATCH v4 5/5] virt: vmgenid: add support for devicetree bindings
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On 09/04/2024 18:07, Sudan Landge wrote:
> Extend the vmgenid platform driver to support devicetree bindings.
> With this support, hypervisors can send vmgenid notifications to
> the virtual machine without the need to enable ACPI.
> The bindings are located at:
> Documentation/devicetree/bindings/rng/microsoft,vmgenid.yaml
>
> Signed-off-by: Sudan Landge <sudanl@amazon.com>
> ---
> drivers/virt/vmgenid.c | 53 ++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 51 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/virt/vmgenid.c b/drivers/virt/vmgenid.c
> index 3d93e3fb94c4..e1ad74116c0c 100644
> --- a/drivers/virt/vmgenid.c
> +++ b/drivers/virt/vmgenid.c
> @@ -2,12 +2,13 @@
> /*
> * Copyright (C) 2022 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
> *
> - * The "Virtual Machine Generation ID" is exposed via ACPI and changes when a
> + * The "Virtual Machine Generation ID" is exposed via ACPI or DT and changes when a
> * virtual machine forks or is cloned. This driver exists for shepherding that
> * information to random.c.
> */
>
> #include <linux/acpi.h>
> +#include <linux/interrupt.h>
> #include <linux/kernel.h>
> #include <linux/module.h>
> #include <linux/platform_device.h>
> @@ -20,6 +21,7 @@ enum { VMGENID_SIZE = 16 };
> struct vmgenid_state {
> u8 *next_id;
> u8 this_id[VMGENID_SIZE];
> + int irq;
> };
>
> static void vmgenid_notify(struct device *device)
> @@ -43,6 +45,14 @@ vmgenid_acpi_handler(acpi_handle __always_unused handle,
> vmgenid_notify(dev);
> }
>
> +static __maybe_unused irqreturn_t
> +vmgenid_of_irq_handler(int __always_unused irq, void *dev)
> +{
> + vmgenid_notify(dev);
> +
> + return IRQ_HANDLED;
> +}
> +
> static int __maybe_unused
> setup_vmgenid_state(struct vmgenid_state *state, u8 *next_id)
> {
> @@ -106,6 +116,35 @@ static int vmgenid_add_acpi(struct device __maybe_unused *dev,
> #endif
> }
>
> +static int vmgenid_add_of(struct platform_device *pdev,
> + struct vmgenid_state *state)
> +{
> + u8 *virt_addr;
> + int ret = 0;
> +
> + virt_addr = (u8 *)devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
> + if (IS_ERR(virt_addr))
> + return PTR_ERR(virt_addr);
> +
> + ret = setup_vmgenid_state(state, virt_addr);
> + if (ret)
> + return ret;
> +
> + ret = platform_get_irq(pdev, 0);
> + if (ret < 0)
> + return ret;
> +
> + state->irq = ret;
> + pdev->dev.driver_data = state;
> +
> + ret = devm_request_irq(&pdev->dev, state->irq, vmgenid_of_irq_handler,
> + IRQF_SHARED, "vmgenid", &pdev->dev);
> + if (ret)
> + pdev->dev.driver_data = NULL;
> +
> + return ret;
> +}
> +
> static int vmgenid_add(struct platform_device *pdev)
> {
> struct vmgenid_state *state;
> @@ -116,7 +155,10 @@ static int vmgenid_add(struct platform_device *pdev)
> if (!state)
> return -ENOMEM;
>
> - ret = vmgenid_add_acpi(dev, state);
> + if (dev->of_node)
> + ret = vmgenid_add_of(pdev, state);
> + else
> + ret = vmgenid_add_acpi(dev, state);
>
> if (ret)
> devm_kfree(dev, state);
> @@ -124,6 +166,12 @@ static int vmgenid_add(struct platform_device *pdev)
> return ret;
> }
>
> +static const struct of_device_id vmgenid_of_ids[] = {
> + { .compatible = "microsoft,vmgenid", },
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, vmgenid_of_ids);
> +
> static const struct acpi_device_id vmgenid_acpi_ids[] = {
> { "VMGENCTR", 0 },
> { "VM_GEN_COUNTER", 0 },
> @@ -136,6 +184,7 @@ static struct platform_driver vmgenid_plaform_driver = {
> .driver = {
> .name = "vmgenid",
> .acpi_match_table = vmgenid_acpi_ids,
> + .of_match_table = vmgenid_of_ids,
> },
> };
>
Due to a mail server error this last patch of the vmgenid series,
"[PATCH v4 0/5] virt: vmgenid: Add devicetree bindings support", got
sent separately. Apologies for this. I will resend the patches to
correct this issue so, I request reviewers to please ignore this patch.

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