hw/i386/acpi-build: Turn build_q35_osc_method into a generic method

GPEX acpi_dsdt_add_pci_osc() does basically the same as
build_q35_osc_method().

Rename build_q35_osc_method() into build_pci_host_bridge_osc_method()
and move it into hw/acpi/pci.c. In a subsequent patch we will
use this later in place of acpi_dsdt_add_pci_osc().

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20250714080639.2525563-9-eric.auger@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 50 insertions, 0 deletions

diff --git a/hw/acpi/pci.c b/hw/acpi/pci.c
index d511a85029..2228f1245e 100644
--- a/hw/acpi/pci.c
+++ b/hw/acpi/pci.c
@@ -301,3 +301,53 @@ void build_srat_generic_affinity_structures(GArray *table_data)
     object_child_foreach_recursive(object_get_root(), build_acpi_generic_port,
                                    table_data);
 }
+
+Aml *build_pci_host_bridge_osc_method(bool enable_native_pcie_hotplug)
+{
+    Aml *if_ctx;
+    Aml *if_ctx2;
+    Aml *else_ctx;
+    Aml *method;
+    Aml *a_cwd1 = aml_name("CDW1");
+    Aml *a_ctrl = aml_local(0);
+
+    method = aml_method("_OSC", 4, AML_NOTSERIALIZED);
+    aml_append(method, aml_create_dword_field(aml_arg(3), aml_int(0), "CDW1"));
+
+    if_ctx = aml_if(aml_equal(
+        aml_arg(0), aml_touuid("33DB4D5B-1FF7-401C-9657-7441C03DD766")));
+    aml_append(if_ctx, aml_create_dword_field(aml_arg(3), aml_int(4), "CDW2"));
+    aml_append(if_ctx, aml_create_dword_field(aml_arg(3), aml_int(8), "CDW3"));
+
+    aml_append(if_ctx, aml_store(aml_name("CDW3"), a_ctrl));
+
+    /*
+     * Always allow native PME, AER (no dependencies)
+     * Allow SHPC (PCI bridges can have SHPC controller)
+     * Disable PCIe Native Hot-plug if ACPI PCI Hot-plug is enabled.
+     */
+    aml_append(if_ctx, aml_and(a_ctrl,
+        aml_int(0x1E | (enable_native_pcie_hotplug ? 0x1 : 0x0)), a_ctrl));
+
+    if_ctx2 = aml_if(aml_lnot(aml_equal(aml_arg(1), aml_int(1))));
+    /* Unknown revision */
+    aml_append(if_ctx2, aml_or(a_cwd1, aml_int(0x08), a_cwd1));
+    aml_append(if_ctx, if_ctx2);
+
+    if_ctx2 = aml_if(aml_lnot(aml_equal(aml_name("CDW3"), a_ctrl)));
+    /* Capabilities bits were masked */
+    aml_append(if_ctx2, aml_or(a_cwd1, aml_int(0x10), a_cwd1));
+    aml_append(if_ctx, if_ctx2);
+
+    /* Update DWORD3 in the buffer */
+    aml_append(if_ctx, aml_store(a_ctrl, aml_name("CDW3")));
+    aml_append(method, if_ctx);
+
+    else_ctx = aml_else();
+    /* Unrecognized UUID */
+    aml_append(else_ctx, aml_or(a_cwd1, aml_int(4), a_cwd1));
+    aml_append(method, else_ctx);
+
+    aml_append(method, aml_return(aml_arg(3)));
+    return method;
+}