soc/intel/xeon_sp/chip_common: Improve the domain ID

Use a union to access the PCI domain ID.
This will become handy in the following commits to gather meta-data
from the domain ID.

Change-Id: I5c371961768410167a571358f6f366847a259eb6
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/80099
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/xeon_sp/chip_common.c

@@ -12,12 +12,14 @@
 static const STACK_RES *domain_to_stack_res(const struct device *dev)
 {
 	assert(dev->path.type == DEVICE_PATH_DOMAIN);
-	const unsigned int dn = dev->path.domain.domain;
+	const union xeon_domain_path dn = {
+		.domain_path = dev->path.domain.domain
+	};
 
 	const IIO_UDS *hob = get_iio_uds();
 	assert(hob != NULL);
 
-	return &hob->PlatformData.IIO_resource[dn / MAX_LOGIC_IIO_STACK].StackRes[dn % MAX_LOGIC_IIO_STACK];
+	return &hob->PlatformData.IIO_resource[dn.socket].StackRes[dn.stack];
 }
 
 void iio_pci_domain_read_resources(struct device *dev)
@@ -101,6 +103,7 @@ static struct device_operations iio_pcie_domain_ops = {
 void attach_iio_stacks(struct device *dev)
 {
 	const IIO_UDS *hob = get_iio_uds();
+	union xeon_domain_path dn = { .domain_path = 0 };
 	if (!hob)
 		return;
 
@@ -113,15 +116,20 @@ void attach_iio_stacks(struct device *dev)
 			if (ri->BusBase > ri->BusLimit)
 				continue;
 
+			/* Prepare domain path */
+			dn.socket = s;
+			dn.stack = x;
+			dn.bus = ri->BusBase;
+
 			if (!is_pcie_iio_stack_res(ri)) {
 				if (CONFIG(HAVE_IOAT_DOMAINS))
-					soc_create_ioat_domains(dev->bus, ri);
+					soc_create_ioat_domains(dn, dev->bus, ri);
 				continue;
 			}
 
 			struct device_path path;
 			path.type = DEVICE_PATH_DOMAIN;
-			path.domain.domain = s * MAX_LOGIC_IIO_STACK + x;
+			path.domain.domain = dn.domain_path;
 			struct device *iio_domain = alloc_dev(dev->bus, &path);
 			if (iio_domain == NULL)
 				die("%s: out of memory.\n", __func__);

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

@@ -5,10 +5,20 @@
 
 #include <hob_iiouds.h>
 
+union xeon_domain_path {
+	unsigned int domain_path;
+	struct {
+		u8 bus;
+		u8 stack;
+		u8 socket;
+		u8 unused;
+	};
+};
+
 void iio_pci_domain_read_resources(struct device *dev);
 void iio_pci_domain_scan_bus(struct device *dev);
 void attach_iio_stacks(struct device *dev);
 
-void soc_create_ioat_domains(struct bus *bus, const STACK_RES *sr);
+void soc_create_ioat_domains(union xeon_domain_path path, struct bus *bus, const STACK_RES *sr);
 
 #endif /* _CHIP_COMMON_H_ */

src/soc/intel/xeon_sp/spr/ioat.c

@@ -23,15 +23,20 @@ static struct device_operations ioat_domain_ops = {
 	.scan_bus = pci_host_bridge_scan_bus,
 };
 
-static void create_ioat_domain(struct bus *const upstream, const unsigned int domain_base,
+static void create_ioat_domain(const union xeon_domain_path dp, struct bus *const upstream,
 				const unsigned int bus_base, const unsigned int bus_limit,
 				const resource_t mem32_base, const resource_t mem32_limit,
 				const resource_t mem64_base, const resource_t mem64_limit)
 {
+	union xeon_domain_path new_path = {
+		.domain_path = dp.domain_path
+	};
+	new_path.bus = bus_base;
+
 	struct device_path path = {
 		.type = DEVICE_PATH_DOMAIN,
 		.domain = {
-			.domain = domain_base + bus_base,
+			.domain = new_path.domain_path,
 		},
 	};
 	struct device *const domain = alloc_dev(upstream, &path);
@@ -69,10 +74,8 @@ static void create_ioat_domain(struct bus *const upstream, const unsigned int do
 	}
 }
 
-void soc_create_ioat_domains(struct bus *const bus, const STACK_RES *const sr)
+void soc_create_ioat_domains(const union xeon_domain_path path, struct bus *const bus, const STACK_RES *const sr)
 {
-	const unsigned int domain_base = MAX_SOCKET * MAX_LOGIC_IIO_STACK;
-
 	if (sr->BusLimit < sr->BusBase + HQM_BUS_OFFSET + HQM_RESERVED_BUS) {
 		printk(BIOS_WARNING,
 			"Ignoring IOAT domain with limited bus range.\n");
@@ -96,14 +99,14 @@ void soc_create_ioat_domains(struct bus *const bus, const STACK_RES *const sr)
 	mem64_limit = mem64_base + CPM_MMIO_SIZE - 1;
 	bus_base = sr->BusBase + CPM_BUS_OFFSET;
 	bus_limit = bus_base + CPM_RESERVED_BUS;
-	create_ioat_domain(bus, domain_base, bus_base, bus_limit, 0, -1, mem64_base, mem64_limit);
+	create_ioat_domain(path, bus, bus_base, bus_limit, 0, -1, mem64_base, mem64_limit);
 
 	/* HQM0 */
 	mem64_base = mem64_limit + 1;
 	mem64_limit = mem64_base + HQM_MMIO_SIZE - 1;
 	bus_base = sr->BusBase + HQM_BUS_OFFSET;
 	bus_limit = bus_base + HQM_RESERVED_BUS;
-	create_ioat_domain(bus, domain_base, bus_base, bus_limit, 0, -1, mem64_base, mem64_limit);
+	create_ioat_domain(path, bus, bus_base, bus_limit, 0, -1, mem64_base, mem64_limit);
 
 	/* CPM1 (optional) */
 	mem64_base = mem64_limit + 1;
@@ -111,7 +114,7 @@ void soc_create_ioat_domains(struct bus *const bus, const STACK_RES *const sr)
 	bus_base = sr->BusBase + CPM1_BUS_OFFSET;
 	bus_limit = bus_base + CPM_RESERVED_BUS;
 	if (bus_limit <= sr->BusLimit)
-		create_ioat_domain(bus, domain_base, bus_base, bus_limit, 0, -1, mem64_base, mem64_limit);
+		create_ioat_domain(path, bus, bus_base, bus_limit, 0, -1, mem64_base, mem64_limit);
 
 	/* HQM1 (optional) */
 	mem64_base = mem64_limit + 1;
@@ -119,13 +122,13 @@ void soc_create_ioat_domains(struct bus *const bus, const STACK_RES *const sr)
 	bus_base = sr->BusBase + HQM1_BUS_OFFSET;
 	bus_limit = bus_base + HQM_RESERVED_BUS;
 	if (bus_limit <= sr->BusLimit)
-		create_ioat_domain(bus, domain_base, bus_base, bus_limit, 0, -1, mem64_base, mem64_limit);
+		create_ioat_domain(path, bus, bus_base, bus_limit, 0, -1, mem64_base, mem64_limit);
 
 	/* DINO */
 	mem64_base = mem64_limit + 1;
 	mem64_limit = sr->PciResourceMem64Limit;
 	bus_base = sr->BusBase;
 	bus_limit = bus_base;
-	create_ioat_domain(bus, domain_base, bus_base, bus_limit, sr->PciResourceMem32Base, sr->PciResourceMem32Limit,
+	create_ioat_domain(path, bus, bus_base, bus_limit, sr->PciResourceMem32Base, sr->PciResourceMem32Limit,
 		mem64_base, mem64_limit);
 }