Re: [PATCH 1/1] hw/i386/acpi-build: add OSHP method support for SHPC driver load

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Jun 24, 2024 at 09:14:26PM +0800, Shiyuan Gao wrote:
> SHPC driver will be loaded fail in i440fx platform, the dmesg shows
> that OS cannot get control of SHPC hotplug and hotplug device to
> the PCI bridge will fail when we use SHPC Native type:
> 
>   [3.336059] shpchp 0000:00:03.0: Requesting control of SHPC hotplug via OSHP (\_SB_.PCI0.S28_)
>   [3.337408] shpchp 0000:00:03.0: Requesting control of SHPC hotplug via OSHP (\_SB_.PCI0)
>   [3.338710] shpchp 0000:00:03.0: Cannot get control of SHPC hotplug
> 
> Add OSHP method support for SHPC driver load, the hotplug device to the PCI bridge will
> success when we use SHPC Native type.
> 
>   [1.703975] shpchp 0000:00:03.0: Requesting control of SHPC hotplug via OSHP (\_SB_.PCI0.S18_)
>   [1.704934] shpchp 0000:00:03.0: Requesting control of SHPC hotplug via OSHP (\_SB_.PCI0)
>   [1.705855] shpchp 0000:00:03.0: Gained control of SHPC hotplug (\_SB_.PCI0)
>   [1.707054] shpchp 0000:00:03.0: HPC vendor_id 1b36 device_id 1 ss_vid 0 ss_did 0
> 
> According to the acpi_pcihp, the OSHP method don't need parameter and return value now.
> 
>   shpc_probe
>     --> acpi_get_hp_hw_control_from_firmware
>       --> acpi_run_oshp
>         --> status = acpi_evaluate_object(handle, METHOD_NAME_OSHP, NULL, NULL);
> 
> Signed-off-by: Shiyuan Gao <gaoshiyuan@baidu.com>
> ---
>  hw/i386/acpi-build.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index f4e366f64f..79622e6939 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -1412,6 +1412,18 @@ static void build_acpi0017(Aml *table)
>      aml_append(table, scope);
>  }
>  
> +static Aml *build_oshp_method(void)
> +{
> +    Aml *method;
> +
> +    /*
> +     * Request control of SHPC hotplug via OSHP method,
> +     * no need parameter and return value in acpi_pcihp.
> +     */

Quote spec and earliest version documenting this, please.


> +    method = aml_method("OSHP", 0, AML_NOTSERIALIZED);
> +    return method;
> +}
> +
>  static void
>  build_dsdt(GArray *table_data, BIOSLinker *linker,
>             AcpiPmInfo *pm, AcpiMiscInfo *misc,
> @@ -1452,6 +1464,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
>          aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A03")));
>          aml_append(dev, aml_name_decl("_UID", aml_int(pcmc->pci_root_uid)));
>          aml_append(dev, aml_pci_edsm());
> +        aml_append(dev, build_oshp_method());
>          aml_append(sb_scope, dev);
>          aml_append(dsdt, sb_scope);
>  
> @@ -1586,6 +1599,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
>                  aml_append(dev, build_q35_osc_method(true));
>              } else {
>                  aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A03")));
> +                aml_append(dev, build_oshp_method());
>              }
>  
>              if (numa_node != NUMA_NODE_UNASSIGNED) {
> -- 
> 2.27.0