arch/x86/acpi_device: Add a helper function to write PCI device

This change adds a helper function to write a PCI device with _ADR
and _STA defined for it.

BUG=b:153858769

Signed-off-by: Furquan Shaikh <furquan@google.com>
Change-Id: I932af917d91198876fe8e90af9bb7a2531bd8960
Reviewed-on: https://review.coreboot.org/c/coreboot/+/40674
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

2 files changed, 41 insertions, 0 deletions

diff --git a/src/arch/x86/acpi_device.c b/src/arch/x86/acpi_device.c
index 9f1710e35f..2c461558a2 100644
--- a/src/arch/x86/acpi_device.c
+++ b/src/arch/x86/acpi_device.c
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /* This file is part of the coreboot project. */
 
+#include <assert.h>
 #include <string.h>
 #include <arch/acpi.h>
 #include <arch/acpi_device.h>
@@ -927,3 +928,34 @@ struct acpi_dp *acpi_dp_add_gpio(struct acpi_dp *dp, const char *name,
 
 	return gpio;
 }
+
+/*
+ * This function writes a PCI device with _ADR object:
+ * Example:
+ * Scope (\_SB.PCI0)
+ * {
+ *    Device (IGFX)
+ *    {
+ *       Name (_ADR, 0x0000000000000000)
+ *       Method (_STA, 0, NotSerialized) { Return (status) }
+ *    }
+ * }
+ */
+void acpi_device_write_pci_dev(struct device *dev)
+{
+	const char *scope = acpi_device_scope(dev);
+	const char *name = acpi_device_name(dev);
+
+	assert(dev->path.type == DEVICE_PATH_PCI);
+	assert(name);
+	assert(scope);
+
+	acpigen_write_scope(scope);
+	acpigen_write_device(name);
+
+	acpigen_write_ADR_pci_device(dev);
+	acpigen_write_STA(acpi_device_status(dev));
+
+	acpigen_pop_len(); /* Device */
+	acpigen_pop_len(); /* Scope */
+}
diff --git a/src/arch/x86/include/arch/acpi_device.h b/src/arch/x86/include/arch/acpi_device.h
index e9c5cd4de2..362efc4a62 100644
--- a/src/arch/x86/include/arch/acpi_device.h
+++ b/src/arch/x86/include/arch/acpi_device.h
@@ -501,4 +501,13 @@ size_t acpi_dp_add_property_list(struct acpi_dp *dp,
 /* Write Device Property hierarchy and clean up resources */
 void acpi_dp_write(struct acpi_dp *table);
 
+/*
+ * Helper function to write a PCI device with _ADR object defined.
+ *
+ * IMPORTANT: Scope of a device created in SSDT cannot be used to add ACPI nodes under that
+ * scope in DSDT. So, if there are any references to this PCI device scope required from static
+ * asl files, do not use this function and instead add the device to DSDT as well.
+ */
+void acpi_device_write_pci_dev(struct device *dev);
+
 #endif