device/device_util: Use const qualifier

Allows to use the function in more places that expect the
struct device to be readonly.

TEST=Build and boot on intel/archercity CRB

Change-Id: Iac04fe6931a43070f6638b399adbff2ce64829c9
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Signed-off-by: Shuo Liu <shuo.liu@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/81275
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/device/device_util.c

@@ -248,7 +248,7 @@ const char *dev_name(const struct device *dev)
 }
 
 /* Returns the PCI domain for the given PCI device */
-struct device *dev_get_pci_domain(struct device *dev)
+const struct device *dev_get_pci_domain(const struct device *dev)
 {
 	/* Walk up the tree up to the PCI domain */
 	while (dev && dev->upstream && !is_root_device(dev)) {

src/include/device/device.h

@@ -182,7 +182,7 @@ void assign_resources(struct bus *bus);
 const char *dev_name(const struct device *dev);
 const char *dev_path(const struct device *dev);
 u32 dev_path_encode(const struct device *dev);
-struct device *dev_get_pci_domain(struct device *dev);
+const struct device *dev_get_pci_domain(const struct device *dev);
 void dev_set_enabled(struct device *dev, int enable);
 void disable_children(struct bus *bus);
 bool dev_is_active_bridge(struct device *dev);

src/soc/intel/xeon_sp/chip_common.c

@@ -41,12 +41,13 @@ struct device *dev_find_device_on_socket(uint8_t socket, u16 vendor, u16 device)
 static int filter_device_on_stack(struct device *dev, uint8_t socket, uint8_t stack,
 	u16 vendor, u16 device)
 {
-	struct device *domain = dev_get_pci_domain(dev);
-	if (!domain)
-		return 0;
 	if (dev->path.type != DEVICE_PATH_PCI)
 		return 0;
 
+	const struct device *domain = dev_get_pci_domain(dev);
+	if (!domain)
+		return 0;
+
 	union xeon_domain_path dn;
 	dn.domain_path = domain->path.domain.domain;
 
@@ -130,9 +131,9 @@ struct device *dev_find_all_devices_on_domain(struct device *domain, u16 vendor,
  *
  * @return Socket ID the device is attached to, negative number on error.
  */
-int iio_pci_domain_socket_from_dev(struct device *dev)
+int iio_pci_domain_socket_from_dev(const struct device *dev)
 {
-	struct device *domain;
+	const struct device *domain;
 	union xeon_domain_path dn;
 
 	if (dev->path.type == DEVICE_PATH_DOMAIN)
@@ -156,9 +157,9 @@ int iio_pci_domain_socket_from_dev(struct device *dev)
  *
  * @return Stack ID the device is attached to, negative number on error.
  */
-int iio_pci_domain_stack_from_dev(struct device *dev)
+int iio_pci_domain_stack_from_dev(const struct device *dev)
 {
-	struct device *domain;
+	const struct device *domain;
 	union xeon_domain_path dn;
 
 	if (dev->path.type == DEVICE_PATH_DOMAIN)
@@ -224,7 +225,7 @@ void attach_iio_stacks(void)
 	}
 }
 
-bool is_pcie_domain(struct device *dev)
+bool is_pcie_domain(const struct device *dev)
 {
 	if ((!dev) || (dev->path.type != DEVICE_PATH_DOMAIN))
 		return false;
@@ -232,7 +233,7 @@ bool is_pcie_domain(struct device *dev)
 	return strstr(dev->name, DOMAIN_TYPE_PCIE);
 }
 
-bool is_ioat_domain(struct device *dev)
+bool is_ioat_domain(const struct device *dev)
 {
 	if ((!dev) || (dev->path.type != DEVICE_PATH_DOMAIN))
 		return false;
@@ -244,7 +245,7 @@ bool is_ioat_domain(struct device *dev)
 		strstr(dev->name, DOMAIN_TYPE_HQM1));
 }
 
-bool is_ubox_domain(struct device *dev)
+bool is_ubox_domain(const struct device *dev)
 {
 	if ((!dev) || (dev->path.type != DEVICE_PATH_DOMAIN))
 		return false;
@@ -253,7 +254,7 @@ bool is_ubox_domain(struct device *dev)
 		strstr(dev->name, DOMAIN_TYPE_UBX1));
 }
 
-bool is_cxl_domain(struct device *dev)
+bool is_cxl_domain(const struct device *dev)
 {
 	if ((!dev) || (dev->path.type != DEVICE_PATH_DOMAIN))
 		return false;

src/soc/intel/xeon_sp/include/soc/chip_common.h

@@ -70,13 +70,13 @@ struct device *dev_find_all_devices_on_stack(uint8_t socket, uint8_t stack,
 struct device *dev_find_all_devices_on_domain(struct device *domain,
 						u16 vendor, u16 device, struct device *from);
 
-int iio_pci_domain_socket_from_dev(struct device *dev);
-int iio_pci_domain_stack_from_dev(struct device *dev);
+int iio_pci_domain_socket_from_dev(const struct device *dev);
+int iio_pci_domain_stack_from_dev(const struct device *dev);
 
-bool is_pcie_domain(struct device *dev);
-bool is_ioat_domain(struct device *dev);
-bool is_ubox_domain(struct device *dev);
-bool is_cxl_domain(struct device *dev);
+bool is_pcie_domain(const struct device *dev);
+bool is_ioat_domain(const struct device *dev);
+bool is_ubox_domain(const struct device *dev);
+bool is_cxl_domain(const struct device *dev);
 
 #define is_dev_on_pcie_domain(dev) is_pcie_domain(dev_get_pci_domain(dev))
 #define is_dev_on_ioat_domain(dev) is_ioat_domain(dev_get_pci_domain(dev))

src/soc/intel/xeon_sp/uncore_acpi.c

@@ -315,7 +315,7 @@ static unsigned long acpi_create_drhd(unsigned long current, struct device *iomm
 
 	// Add PCIe Ports
 	if (!is_dev_on_domain0(iommu)) {
-		struct device *domain = dev_get_pci_domain(iommu);
+		const struct device *domain = dev_get_pci_domain(iommu);
 		struct device *dev = NULL;
 		while ((dev = dev_bus_each_child(domain->downstream, dev)))
 			if ((dev->hdr_type & 0x7f) == PCI_HEADER_TYPE_BRIDGE)