On Mon, 16 Jun 2025 11:46:35 +0200
Eric Auger <eric.auger@redhat.com> wrote:
> acpi_dsdt_add_pci_osc() name is confusing as it gives the impression
> it appends the _OSC method but in fact it also appends the _DSM method
> for the host bridge. Let's split the function into two separate ones
> and let them return the method Aml pointer instead. This matches the
> way it is done on x86 (build_q35_osc_method). In a subsequent patch
> we will replace the gpex method by the q35 implementation that will
> become shared between ARM and x86.
>
> acpi_dsdt_add_host_bridge_methods is a new top helper that generates
> both the _OSC and _DSM methods.
I'd get rid of wrapper, but it's not something that worth to fight over,
so
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
>
> We take the opportunity to move SUPP and CTRL in the _osc method
> that use them.
>
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>
> ---
>
> v2 -> v3:
> - moved
> aml_append(dev, aml_name_decl("SUPP", aml_int(0)));
> aml_append(dev, aml_name_decl("CTRL", aml_int(0)));
> into the _osc function. (Jonathan)
> hence discarded Gustavo's and Igor's R-bs
> ---
> hw/pci-host/gpex-acpi.c | 32 +++++++++++++++++++++-----------
> 1 file changed, 21 insertions(+), 11 deletions(-)
>
> diff --git a/hw/pci-host/gpex-acpi.c b/hw/pci-host/gpex-acpi.c
> index f34b7cf25e..80fc2bf032 100644
> --- a/hw/pci-host/gpex-acpi.c
> +++ b/hw/pci-host/gpex-acpi.c
> @@ -50,14 +50,12 @@ static void acpi_dsdt_add_pci_route_table(Aml *dev, uint32_t irq,
> }
> }
>
> -static void acpi_dsdt_add_pci_osc(Aml *dev, bool enable_native_pcie_hotplug)
> +static Aml *build_host_bridge_osc(bool enable_native_pcie_hotplug)
> {
> - Aml *method, *UUID, *ifctx, *ifctx1, *elsectx, *buf;
> -
> - /* Declare an _OSC (OS Control Handoff) method */
> - aml_append(dev, aml_name_decl("SUPP", aml_int(0)));
> - aml_append(dev, aml_name_decl("CTRL", aml_int(0)));
> + Aml *method, *UUID, *ifctx, *ifctx1, *elsectx;
> method = aml_method("_OSC", 4, AML_NOTSERIALIZED);
> + aml_append(method, aml_name_decl("SUPP", aml_int(0)));
> + aml_append(method, aml_name_decl("CTRL", aml_int(0)));
> aml_append(method,
> aml_create_dword_field(aml_arg(3), aml_int(0), "CDW1"));
>
> @@ -103,9 +101,13 @@ static void acpi_dsdt_add_pci_osc(Aml *dev, bool enable_native_pcie_hotplug)
> aml_name("CDW1")));
> aml_append(elsectx, aml_return(aml_arg(3)));
> aml_append(method, elsectx);
> - aml_append(dev, method);
> + return method;
> +}
>
> - method = aml_method("_DSM", 4, AML_NOTSERIALIZED);
> +static Aml *build_host_bridge_dsm(void)
> +{
> + Aml *method = aml_method("_DSM", 4, AML_NOTSERIALIZED);
> + Aml *UUID, *ifctx, *ifctx1, *buf;
>
> /* PCI Firmware Specification 3.0
> * 4.6.1. _DSM for PCI Express Slot Information
> @@ -124,7 +126,15 @@ static void acpi_dsdt_add_pci_osc(Aml *dev, bool enable_native_pcie_hotplug)
> byte_list[0] = 0;
> buf = aml_buffer(1, byte_list);
> aml_append(method, aml_return(buf));
> - aml_append(dev, method);
> + return method;
> +}
> +
> +static void acpi_dsdt_add_host_bridge_methods(Aml *dev,
> + bool enable_native_pcie_hotplug)
> +{
> + /* Declare an _OSC (OS Control Handoff) method */
> + aml_append(dev, build_host_bridge_osc(enable_native_pcie_hotplug));
> + aml_append(dev, build_host_bridge_dsm());
> }
>
> void acpi_dsdt_add_gpex(Aml *scope, struct GPEXConfig *cfg)
> @@ -193,7 +203,7 @@ void acpi_dsdt_add_gpex(Aml *scope, struct GPEXConfig *cfg)
> if (is_cxl) {
> build_cxl_osc_method(dev);
> } else {
> - acpi_dsdt_add_pci_osc(dev, true);
> + acpi_dsdt_add_host_bridge_methods(dev, true);
> }
>
> aml_append(scope, dev);
> @@ -268,7 +278,7 @@ void acpi_dsdt_add_gpex(Aml *scope, struct GPEXConfig *cfg)
> }
> aml_append(dev, aml_name_decl("_CRS", rbuf));
>
> - acpi_dsdt_add_pci_osc(dev, true);
> + acpi_dsdt_add_host_bridge_methods(dev, true);
>
> Aml *dev_res0 = aml_device("%s", "RES0");
> aml_append(dev_res0, aml_name_decl("_HID", aml_string("PNP0C02")));