RE: [PATCH v9 5/5] Driver: VMBus: Add Devicetree support

Michael Kelley (LINUX)
2023-03-20T18:17:45Z

From: Saurabh Sengar <ssengar@linux.microsoft.com> Sent: Monday, March 20, 2023 12:48 AM
>
> Update the driver to support Devicetree boot as well along with ACPI.
> At present the Devicetree parsing only provides the mmio region info
> and is not the exact copy of ACPI parsing. This is sufficient to cater
> all the current Devicetree usecases for VMBus.
>
> Currently Devicetree is supported only for x86 systems.
>
> Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
> ---
> [V9]
> - Add vmbus_mmio_remove for error handling
> - Remove logic from !acpi_disabled to acpi_disabled
>
> drivers/hv/Kconfig | 5 ++--
> drivers/hv/vmbus_drv.c | 66 +++++++++++++++++++++++++++++++++++++++---
> 2 files changed, 65 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig
> index 0747a8f1fcee..47132b30b7ee 100644
> --- a/drivers/hv/Kconfig
> +++ b/drivers/hv/Kconfig
> @@ -4,11 +4,12 @@ menu "Microsoft Hyper-V guest support"
>
> config HYPERV
> tristate "Microsoft Hyper-V client drivers"
> - depends on ACPI && ((X86 && X86_LOCAL_APIC && HYPERVISOR_GUEST) \
> - || (ARM64 && !CPU_BIG_ENDIAN))
> + depends on (X86 && X86_LOCAL_APIC && HYPERVISOR_GUEST) \
> + || (ACPI && ARM64 && !CPU_BIG_ENDIAN)
> select PARAVIRT
> select X86_HV_CALLBACK_VECTOR if X86
> select VMAP_PFN
> + select OF_EARLY_FLATTREE if OF
> help
> Select this option to run Linux as a Hyper-V client operating
> system.
> diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
> index 3ad2fa2b92e7..5de2d3bb8289 100644
> --- a/drivers/hv/vmbus_drv.c
> +++ b/drivers/hv/vmbus_drv.c
> @@ -20,6 +20,7 @@
> #include <linux/completion.h>
> #include <linux/hyperv.h>
> #include <linux/kernel_stat.h>
> +#include <linux/of_address.h>
> #include <linux/clockchips.h>
> #include <linux/cpu.h>
> #include <linux/sched/isolation.h>
> @@ -2143,7 +2144,7 @@ void vmbus_device_unregister(struct hv_device
> *device_obj)
> device_unregister(&device_obj->device);
> }
>
> -
> +#ifdef CONFIG_ACPI
> /*
> * VMBUS is an acpi enumerated device. Get the information we
> * need from DSDT.
> @@ -2253,6 +2254,7 @@ static acpi_status vmbus_walk_resources(struct
> acpi_resource *res, void *ctx)
>
> return AE_OK;
> }
> +#endif
>
> static void vmbus_mmio_remove(void)
> {
> @@ -2273,7 +2275,7 @@ static void vmbus_mmio_remove(void)
> }
> }
>
> -static void vmbus_reserve_fb(void)
> +static void __maybe_unused vmbus_reserve_fb(void)
> {
> resource_size_t start = 0, size;
> struct pci_dev *pdev;
> @@ -2433,6 +2435,7 @@ void vmbus_free_mmio(resource_size_t start,
> resource_size_t size)
> }
> EXPORT_SYMBOL_GPL(vmbus_free_mmio);
>
> +#ifdef CONFIG_ACPI
> static int vmbus_acpi_add(struct platform_device *pdev)
> {
> acpi_status result;
> @@ -2485,10 +2488,54 @@ static int vmbus_acpi_add(struct platform_device *pdev)
> vmbus_mmio_remove();
> return ret_val;
> }
> +#else
> +static int vmbus_acpi_add(struct platform_device *pdev)
> +{
> + return 0;
> +}
> +#endif
> +
> +static int vmbus_device_add(struct platform_device *pdev)
> +{
> + struct resource **cur_res = &hyperv_mmio;
> + struct of_range range;
> + struct of_range_parser parser;
> + struct device_node *np = pdev->dev.of_node;
> + int ret;
> +
> + hv_dev = &pdev->dev;
> +
> + ret = of_range_parser_init(&parser, np);
> + if (ret)
> + return ret;
> +
> + for_each_of_range(&parser, &range) {
> + struct resource *res;
> +
> + res = kzalloc(sizeof(*res), GFP_KERNEL);
> + if (!res) {
> + vmbus_mmio_remove();
> + return -ENOMEM;
> + }
> +
> + res->name = "hyperv mmio";
> + res->flags = range.flags;
> + res->start = range.cpu_addr;
> + res->end = range.cpu_addr + range.size;
> +
> + *cur_res = res;
> + cur_res = &res->sibling;
> + }
> +
> + return ret;
> +}
>
> static int vmbus_platform_driver_probe(struct platform_device *pdev)
> {
> - return vmbus_acpi_add(pdev);
> + if (acpi_disabled)
> + return vmbus_device_add(pdev);
> + else
> + return vmbus_acpi_add(pdev);
> }
>
> static int vmbus_platform_driver_remove(struct platform_device *pdev)
> @@ -2634,7 +2681,17 @@ static int vmbus_bus_resume(struct device *dev)
> #define vmbus_bus_resume NULL
> #endif /* CONFIG_PM_SLEEP */
>
> -static const struct acpi_device_id vmbus_acpi_device_ids[] = {
> +static const __maybe_unused struct of_device_id vmbus_of_match[] = {
> + {
> + .compatible = "microsoft,vmbus",
> + },
> + {
> + /* sentinel */
> + },
> +};
> +MODULE_DEVICE_TABLE(of, vmbus_of_match);
> +
> +static const __maybe_unused struct acpi_device_id vmbus_acpi_device_ids[] = {
> {"VMBUS", 0},
> {"VMBus", 0},
> {"", 0},
> @@ -2668,6 +2725,7 @@ static struct platform_driver vmbus_platform_driver = {
> .driver = {
> .name = "vmbus",
> .acpi_match_table = ACPI_PTR(vmbus_acpi_device_ids),
> + .of_match_table = of_match_ptr(vmbus_of_match),
> .pm = &vmbus_bus_pm,
> .probe_type = PROBE_FORCE_SYNCHRONOUS,
> }
> --
> 2.34.1

Reviewed-by: Michael Kelley <mikelley@microsoft.com>