diff --git a/src/acpi/acpigen_pci.c b/src/acpi/acpigen_pci.c
index 3edf0d0..a23b84c 100644
--- a/src/acpi/acpigen_pci.c
+++ b/src/acpi/acpigen_pci.c
@@ -55,3 +55,308 @@
 
 	acpigen_pop_len(); /* Package */
 }
+
+#define PCI_HOST_BRIDGE_OSC_UUID     "33db4d5b-1ff7-401c-9657-7441c03dd766"
+#define CXL_HOST_BRIDGE_OSC_UUID     "68f2d50b-c469-4d8a-bd3d-941a103fd3fc"
+
+#define OSC_RET_FAILURE              0x02
+#define OSC_RET_UNRECOGNIZED_UUID    0x04
+#define OSC_RET_UNRECOGNIZED_REV     0x08
+#define OSC_RET_CAPABILITIES_MASKED  0x10
+
+#define OSC_QUERY_SUPPORT_SET        0x01
+
+#define ASL_UUID_UNHANDLED           0x00
+#define ASL_UUID_HANDLED             0x01
+
+static void acpigen_OSC_handle_pcie_request(const struct device *domain);
+static void acpigen_OSC_handle_cxl_request(const struct device *domain);
+
+/*
+ * acpigen_write_OSC_pci_domain
+ *
+ * Reference:
+ * 6.2.11 in https://uefi.org/htmlspecs/ACPI_Spec_6_4_html/06_Device_Configuration/Device_Configuration.html
+ *
+ * _OSC ASL Arguments: (4)
+ * Arg0 - A Buffer containing a UUID
+ * Arg1 - An Integer containing a Revision ID of the buffer format
+ * Arg2 - An Integer containing a count of entries in Arg3
+ * Arg3 - A Buffer containing a list of DWORD capabilities
+ *
+ * _OSC ASL Return Value:
+ * A Buffer containing a list of capabilities
+ *
+ * Local Variables Assignment:
+ * Local0 - Temp assigned
+ * Local1 - Temp assigned
+ * Local2 - Not used
+ * Local3 - Not used
+ * Local4 - Not used
+ * Local5 - Not used
+ * Local6 - Record whether the UUID is handled
+ * Local7 - Backs up the input value of Arg3
+ *
+ * Field Definitions:
+ * Name - Width	Source	Offset	Description
+ * --------------------------------
+ * QSUP - DWord	Local7	0x00	Query support
+ * RETE - DWord	Arg3	0x00	Returned errors
+ * SUPP - Dword	Arg3	0x04	PCIe Features that OS supported
+ * CTRL - Dword	Arg3	0x08	PCIe Features that firmware grant control to OS
+ * OTRL - Dword	Local7	0x08	PCIe Features that OS requests for control
+ * SUPC - Dword	Arg3	0x0C	CXL Features that OS supported
+ * CTRC - Dword	Arg3	0x10	CXL Features that firmware grant control to OS
+ * OTRC - Dword	Local7	0x10	CXL Features that OS requests for control
+ */
+void acpigen_write_OSC_pci_domain(const struct device *domain, const bool is_cxl_domain)
+{
+	/*
+	 * Method (_OSC, 4, NotSerialized)
+	 * {
+	 */
+	acpigen_write_method("_OSC", 4);
+
+	/*
+	 *	//
+	 *	// Check revision ID
+	 *	//
+	 *	If (Arg1 != 1)
+	 *	{
+	 *		RETE = OSC_RET_UNRECOGNIZED_REV
+	 *		Return (Arg3)
+	 *	}
+	 */
+	acpigen_write_if();
+	acpigen_emit_byte(LNOT_OP);
+	acpigen_emit_byte(LEQUAL_OP);
+	acpigen_emit_byte(ARG1_OP);
+	acpigen_write_integer(0x1);
+
+	acpigen_write_store_int_to_namestr(OSC_RET_UNRECOGNIZED_REV, "RETE");
+	acpigen_write_return_op(ARG3_OP);
+
+	acpigen_write_if_end();
+
+	/*
+	 *	//
+	 *	// Setup up local variables
+	 *	//
+	 *	Local7 = Arg3
+	 *	CreateDwordField (Local7, 0x00, QSUP)
+	 *	CreateDWordField (Arg3, 0x00, RETE)
+	 *	RETE = 0x0
+	 *	Local6 = ASL_UUID_UNHANDLED
+	 */
+	acpigen_write_store_ops(ARG3_OP, LOCAL7_OP);
+	acpigen_write_create_dword_field(LOCAL7_OP, 0x00, "QSUP");
+	acpigen_write_create_dword_field(ARG3_OP, 0x00, "RETE");
+	acpigen_write_store_int_to_namestr(0x0, "RETE");
+	acpigen_write_store_int_to_op(ASL_UUID_UNHANDLED, LOCAL6_OP);
+
+	/*
+	 *	//
+	 *	// Refer to CXL-3.1-Specification, 9.18.2
+	 *	// A CXL Host Bridge also originates a PCIe hierarchy and will have a
+	 *	// _CID of EISAID("PNP0A08"). As such, a CXL Host Bridge device may expose
+	 *	// both CXL _OSC and PCIe _OSC.
+	 *	//
+	 *
+	 *	If (Arg0 == ToUUID (PCI_HOST_BRIDGE_OSC_UUID))
+	 *	{
+	 *		//
+	 *		// Handle PCIe _OSC request
+	 *		// Mark UUID handled
+	 *		//
+	 *	}
+	 */
+	acpigen_write_if();
+	acpigen_emit_byte(LEQUAL_OP);
+	acpigen_emit_byte(ARG0_OP);
+	acpigen_write_uuid(PCI_HOST_BRIDGE_OSC_UUID);
+
+	acpigen_OSC_handle_pcie_request(domain);
+	acpigen_write_store_int_to_op(ASL_UUID_HANDLED, LOCAL6_OP);
+
+	acpigen_write_if_end();
+
+	if (is_cxl_domain) {
+	/*
+	 *	If (Arg0 == ToUUID (CXL_HOST_BRIDGE_OSC_UUID))
+	 *	{
+	 *		//
+	 *		// Handle CXL _OSC request
+	 *		// Mark UUID handled
+	 *		//
+	 *	}
+	 */
+		acpigen_write_if();
+		acpigen_emit_byte(LEQUAL_OP);
+		acpigen_emit_byte(ARG0_OP);
+		acpigen_write_uuid(CXL_HOST_BRIDGE_OSC_UUID);
+
+		acpigen_OSC_handle_cxl_request(domain);
+		acpigen_write_store_int_to_op(ASL_UUID_HANDLED, LOCAL6_OP);
+
+		acpigen_write_if_end();
+	}
+
+	/*
+	 *	//
+	 *	// Handle unrecognized UUID
+	 *	//
+	 *	If (Local6 == ASL_UUID_UNHANDLED)
+	 *	{
+	 *		RETE = OSC_RET_UNRECOGNIZED_UUID
+	 *	}
+	 */
+	acpigen_write_if_lequal_op_int(LOCAL6_OP, ASL_UUID_UNHANDLED);
+	acpigen_write_store_int_to_namestr(OSC_RET_UNRECOGNIZED_UUID, "RETE");
+	acpigen_write_if_end();
+
+	/*
+	 *	//
+	 *	// All done, return
+	 *	//
+	 *	Return (Arg3)
+	 */
+	acpigen_write_return_op(ARG3_OP);
+
+	/*
+	 * } // Method (_OSC, 4, NotSerialized)
+	 */
+	acpigen_pop_len();
+
+}
+
+void acpigen_OSC_handle_pcie_request(const struct device *domain)
+{
+	uint32_t osc_features = soc_get_granted_pci_features(domain);
+
+	/*
+	 *		If (Arg2 < 2))
+	 *		{
+	 *			RETE = OSC_RET_FAILURE
+	 *			Return (Arg3)
+	 *		}
+	 */
+	acpigen_write_if();
+	acpigen_emit_byte(LLESS_OP);
+	acpigen_emit_byte(ARG2_OP);
+	acpigen_write_integer(0x2);
+
+	acpigen_write_store_int_to_namestr(OSC_RET_FAILURE, "RETE");
+	acpigen_write_return_op(ARG3_OP);
+
+	acpigen_write_if_end();
+
+	/*
+	 *		CreateDWordField (Arg3, 0x04, SUPP)
+	 *		CreateDWordField (Arg3, 0x08, CTRL)
+	 *		CreateDWordField (Local7, 0x08, OTRL)
+	 */
+	acpigen_write_create_dword_field(ARG3_OP, 0x04, "SUPP");
+	acpigen_write_create_dword_field(ARG3_OP, 0x08, "CTRL");
+	acpigen_write_create_dword_field(LOCAL7_OP, 0x08, "OTRL");
+
+	/*
+	 *		// Grant PCIe feature controls to OS
+	 *		CTRL &= osc_features
+	 */
+	acpigen_write_to_integer_from_namestring("CTRL", LOCAL0_OP);
+	acpigen_write_store_int_to_op(osc_features, LOCAL1_OP);
+	acpigen_write_and(LOCAL0_OP, LOCAL1_OP, LOCAL0_OP);
+	acpigen_write_store_op_to_namestr(LOCAL0_OP, "CTRL");
+
+	/*
+	 *		If (CTRL != OTRL)
+	 *		{
+	 *			RETE = OSC_RET_CAPABILITIES_MASKED
+	 *		}
+	 */
+	acpigen_write_if();
+	acpigen_emit_byte(LNOT_OP);
+	acpigen_emit_byte(LEQUAL_OP);
+	acpigen_emit_namestring("CTRL");
+	acpigen_emit_namestring("OTRL");
+	acpigen_write_store_int_to_namestr(OSC_RET_CAPABILITIES_MASKED, "RETE");
+	acpigen_write_if_end();
+};
+
+void acpigen_OSC_handle_cxl_request(const struct device *domain)
+{
+	uint32_t osc_features = soc_get_granted_cxl_features(domain);
+
+	/*
+	 *		If (Arg2 < 4))
+	 *		{
+	 *			RETE = OSC_RET_FAILURE
+	 *			Return (Arg3)
+	 *		}
+	 */
+	acpigen_write_if();
+	acpigen_emit_byte(LLESS_OP);
+	acpigen_emit_byte(ARG2_OP);
+	acpigen_write_integer(0x4);
+
+	acpigen_write_store_int_to_namestr(OSC_RET_FAILURE, "RETE");
+	acpigen_write_return_op(ARG3_OP);
+
+	acpigen_write_if_end();
+
+	/*
+	 *		CreateDWordField (Arg3, 0x0C, SUPC)
+	 *		CreateDWordField (Arg3, 0x10, CTRC)
+	 *		CreateDWordField (Local7, 0x10, OTRC)
+	 */
+	acpigen_write_create_dword_field(ARG3_OP, 0x0C, "SUPC");
+	acpigen_write_create_dword_field(ARG3_OP, 0x10, "CTRC");
+	acpigen_write_create_dword_field(LOCAL7_OP, 0x10, "OTRC");
+
+	/*
+	 *		// Grant CXL feature controls to OS
+	 *		CTRC &= osc_features
+	 */
+	acpigen_write_to_integer_from_namestring("CTRC", LOCAL0_OP);
+	acpigen_write_store_int_to_op(osc_features, LOCAL1_OP);
+	acpigen_write_and(LOCAL0_OP, LOCAL1_OP, LOCAL0_OP);
+	acpigen_write_store_op_to_namestr(LOCAL0_OP, "CTRC");
+
+	/*
+	 *		If (CTRC != OTRC)
+	 *		{
+	 *			RETE = OSC_RET_CAPABILITIES_MASKED
+	 *		}
+	 */
+	acpigen_write_if();
+	acpigen_emit_byte(LNOT_OP);
+	acpigen_emit_byte(LEQUAL_OP);
+	acpigen_emit_namestring("CTRC");
+	acpigen_emit_namestring("OTRC");
+	acpigen_write_store_int_to_namestr(OSC_RET_CAPABILITIES_MASKED, "RETE");
+	acpigen_write_if_end();
+};
+
+__weak uint32_t soc_get_granted_pci_features(const struct device *domain)
+{
+	/*
+	 * By default grant no features to OS, which equals to the case where _OSC
+	 * is absent.
+	 *
+	 * Refer to PCI firmware specification, revision 3.1.
+	 * If the _OSC control method is absent from the scope of a host bridge device, then
+	 * the operating system must not enable or attempt to use any features defined in this
+	 * section for the hierarchy originated by the host bridge. Doing so could contend with
+	 * platform firmware operations or produce undesired results.
+	 */
+	return 0;
+}
+
+__weak uint32_t soc_get_granted_cxl_features(const struct device *domain)
+{
+	/*
+	 * By default grant no features to OS, which equals to the case where _OSC
+	 * is absent.
+	 */
+	return 0;
+}
diff --git a/src/include/acpi/acpigen_pci.h b/src/include/acpi/acpigen_pci.h
index 69216ec..7a07423 100644
--- a/src/include/acpi/acpigen_pci.h
+++ b/src/include/acpi/acpigen_pci.h
@@ -7,6 +7,13 @@
 #include <device/pci_def.h>
 #include <device/pci_type.h>
 
+#define PCIE_NATIVE_HOTPLUG_CONTROL  0x01
+#define SHPC_NATIVE_HOTPLUG_CONTROL  0x02
+#define PCIE_PME_CONTROL             0x04
+#define PCIE_AER_CONTROL             0x08
+#define PCIE_CAP_STRUCTURE_CONTROL   0x10
+#define PCIE_LTR_CONTROL             0x20
+
 void acpigen_write_ADR_pci_devfn(pci_devfn_t devfn);
 void acpigen_write_ADR_pci_device(const struct device *dev);
 
@@ -16,4 +23,8 @@
 
 void pci_domain_fill_ssdt(const struct device *domain);
 
+void acpigen_write_OSC_pci_domain(const struct device *domain, const bool is_cxl_domain);
+uint32_t soc_get_granted_pci_features(const struct device *domain);
+uint32_t soc_get_granted_cxl_features(const struct device *domain);
+
 #endif /* ACPIGEN_PCI_H */