device: Add support for multiple PCI segment groups

Add initial support for multiple PCI segment groups. Instead of
modifying secondary in the bus struct introduce a new segment_group
struct element and keep existing common code.

Since all platforms currently only use 1 segment this is not a
functional change. On platforms that support more than 1 segment the
segment has to be set when creating the PCI domain.

Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: Ied3313c41896362dd989ee2ab1b1bcdced840aa8
Reviewed-on: https://review.coreboot.org/c/coreboot/+/79927
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Martin Roth <martin.roth@amd.corp-partner.google.com>

7 files changed, 43 insertions, 18 deletions

diff --git a/src/device/Kconfig b/src/device/Kconfig
index 5202c186b46c..e5b90bbcb081 100644
--- a/src/device/Kconfig
+++ b/src/device/Kconfig
@@ -589,6 +589,13 @@ config ECAM_MMCONF_BASE_ADDRESS
 config ECAM_MMCONF_BUS_NUMBER
 	int
 	depends on ECAM_MMCONF_SUPPORT
+	help
+	  Total number of PCI buses in the system across all segment groups.
+	  The number needs to be a power of 2. For values <= 256,
+	  PCI_BUSES_PER_SEGMENT_GROUP is CONFIG_ECAM_MMCONF_BUS_NUMBER and
+	  PCI_SEGMENT_GROUP_COUNT is 1. For values > 256,
+	  PCI_BUSES_PER_SEGMENT_GROUP is 256 and PCI_SEGMENT_GROUP_COUNT is
+	  CONFIG_ECAM_MMCONF_BUS_NUMBER / 256.
 
 config ECAM_MMCONF_LENGTH
 	hex
@@ -597,6 +604,8 @@ config ECAM_MMCONF_LENGTH
 	default 0x04000000 if ECAM_MMCONF_BUS_NUMBER = 64
 	default 0x08000000 if ECAM_MMCONF_BUS_NUMBER = 128
 	default 0x10000000 if ECAM_MMCONF_BUS_NUMBER = 256
+	default 0x20000000 if ECAM_MMCONF_BUS_NUMBER = 512
+	default 0x80000000 if ECAM_MMCONF_BUS_NUMBER = 1024
 	default 0x0
 
 config PCI_ALLOW_BUS_MASTER
diff --git a/src/device/device.c b/src/device/device.c
index a635e731dd8f..811b70937cf4 100644
--- a/src/device/device.c
+++ b/src/device/device.c
@@ -152,8 +152,8 @@ static void read_resources(struct bus *bus)
 {
 	struct device *curdev;
 
-	printk(BIOS_SPEW, "%s %s bus %d link: %d\n", dev_path(bus->dev),
-	       __func__, bus->secondary, bus->link_num);
+	printk(BIOS_SPEW, "%s %s segment group %d bus %d link: %d\n", dev_path(bus->dev),
+	       __func__, bus->segment_group, bus->secondary, bus->link_num);
 
 	/* Walk through all devices and find which resources they need. */
 	for (curdev = bus->children; curdev; curdev = curdev->sibling) {
@@ -176,8 +176,8 @@ static void read_resources(struct bus *bus)
 			read_resources(link);
 	}
 	post_log_clear();
-	printk(BIOS_SPEW, "%s %s bus %d link: %d done\n",
-	       dev_path(bus->dev), __func__, bus->secondary, bus->link_num);
+	printk(BIOS_SPEW, "%s %s segment group %d bus %d link: %d done\n",
+	       dev_path(bus->dev), __func__, bus->segment_group, bus->secondary, bus->link_num);
 }
 
 struct device *vga_pri = NULL;
@@ -266,8 +266,8 @@ void assign_resources(struct bus *bus)
 {
 	struct device *curdev;
 
-	printk(BIOS_SPEW, "%s %s, bus %d link: %d\n",
-	       dev_path(bus->dev), __func__, bus->secondary, bus->link_num);
+	printk(BIOS_SPEW, "%s %s, segment group %d bus %d link: %d\n",
+	       dev_path(bus->dev), __func__, bus->segment_group, bus->secondary, bus->link_num);
 
 	for (curdev = bus->children; curdev; curdev = curdev->sibling) {
 		if (!curdev->enabled || !curdev->resource_list)
@@ -282,8 +282,8 @@ void assign_resources(struct bus *bus)
 		curdev->ops->set_resources(curdev);
 	}
 	post_log_clear();
-	printk(BIOS_SPEW, "%s %s, bus %d link: %d done\n",
-	       dev_path(bus->dev), __func__, bus->secondary, bus->link_num);
+	printk(BIOS_SPEW, "%s %s, segment group %d bus %d link: %d done\n",
+	       dev_path(bus->dev), __func__, bus->segment_group, bus->secondary, bus->link_num);
 }
 
 /**
diff --git a/src/device/device_const.c b/src/device/device_const.c
index a63a62934442..c91c00908d31 100644
--- a/src/device/device_const.c
+++ b/src/device/device_const.c
@@ -35,6 +35,7 @@ static DEVTREE_CONST struct device *dev_find_slot(unsigned int bus,
 	for (dev = all_devices; dev; dev = dev->next) {
 		if ((dev->path.type == DEVICE_PATH_PCI) &&
 		    (dev->bus->secondary == bus) &&
+		    (dev->bus->segment_group == 0) &&
 		    (dev->path.pci.devfn == devfn)) {
 			result = dev;
 			break;
@@ -233,7 +234,7 @@ DEVTREE_CONST struct device *pcidev_path_on_bus(unsigned int bus, pci_devfn_t de
 			dev = dev->next;
 			continue;
 		}
-		if (dev->bus->secondary == bus)
+		if (dev->bus->secondary == bus && dev->bus->segment_group == 0)
 			return pcidev_path_behind(dev->bus, devfn);
 		dev = dev->next;
 	}
diff --git a/src/device/device_util.c b/src/device/device_util.c
index b37d1d9bfc72..ac2d33cdb9ce 100644
--- a/src/device/device_util.c
+++ b/src/device/device_util.c
@@ -97,7 +97,7 @@ u32 dev_path_encode(const struct device *dev)
 	case DEVICE_PATH_ROOT:
 		break;
 	case DEVICE_PATH_PCI:
-		ret |= dev->bus->secondary << 8 | dev->path.pci.devfn;
+		ret |= dev->bus->segment_group << 16 | dev->bus->secondary << 8 | dev->path.pci.devfn;
 		break;
 	case DEVICE_PATH_PNP:
 		ret |= dev->path.pnp.port << 8 | dev->path.pnp.device;
@@ -168,7 +168,8 @@ const char *dev_path(const struct device *dev)
 			break;
 		case DEVICE_PATH_PCI:
 			snprintf(buffer, sizeof(buffer),
-				 "PCI: %02x:%02x.%01x",
+				 "PCI: %02x:%02x:%02x.%01x",
+				 dev->bus->segment_group,
 				 dev->bus->secondary,
 				 PCI_SLOT(dev->path.pci.devfn),
 				 PCI_FUNC(dev->path.pci.devfn));
@@ -525,7 +526,8 @@ void report_resource_stored(struct device *dev, const struct resource *resource,
 
 	if (dev->link_list && (resource->flags & IORESOURCE_PCI_BRIDGE)) {
 		snprintf(buf, sizeof(buf),
-			 "bus %02x ", dev->link_list->secondary);
+			 "seg %02x bus %02x ", dev->link_list->segment_group,
+			 dev->link_list->secondary);
 	}
 	printk(BIOS_DEBUG, "%s %02lx <- [0x%016llx - 0x%016llx] size 0x%08llx "
 	       "gran 0x%02x %s%s%s\n", dev_path(dev), resource->index,
@@ -982,5 +984,5 @@ bool is_enabled_pci(const struct device *pci)
 
 bool is_pci_dev_on_bus(const struct device *pci, unsigned int bus)
 {
-	return is_pci(pci) && pci->bus->secondary == bus;
+	return is_pci(pci) && pci->bus->segment_group == 0 && pci->bus->secondary == bus;
 }
diff --git a/src/device/pci_device.c b/src/device/pci_device.c
index b356c2695bb6..acdad421c536 100644
--- a/src/device/pci_device.c
+++ b/src/device/pci_device.c
@@ -846,6 +846,12 @@ static int should_run_oprom(struct device *dev, struct rom_header *rom)
 {
 	static int should_run = -1;
 
+	if (dev->bus->segment_group) {
+		printk(BIOS_ERR, "Only option ROMs of devices in first PCI segment group can "
+				 "be run.\n");
+		return 0;
+	}
+
 	if (CONFIG(VENDORCODE_ELTAN_VBOOT))
 		if (rom != NULL)
 			if (!verified_boot_should_run_oprom(rom))
@@ -1314,7 +1320,8 @@ struct device *pci_probe_dev(struct device *dev, struct bus *bus,
  */
 unsigned int pci_match_simple_dev(struct device *dev, pci_devfn_t sdev)
 {
-	return dev->bus->secondary == PCI_DEV2SEGBUS(sdev) &&
+	return dev->bus->secondary == PCI_DEV2BUS(sdev) &&
+			dev->bus->segment_group == PCI_DEV2SEG(sdev) &&
 			dev->path.pci.devfn == PCI_DEV2DEVFN(sdev);
 }
 
@@ -1428,7 +1435,8 @@ void pci_scan_bus(struct bus *bus, unsigned int min_devfn,
 	struct device *dev, **prev;
 	int once = 0;
 
-	printk(BIOS_DEBUG, "PCI: %s for bus %02x\n", __func__, bus->secondary);
+	printk(BIOS_DEBUG, "PCI: %s for segment group %02x bus %02x\n", __func__,
+	       bus->segment_group, bus->secondary);
 
 	/* Maximum sane devfn is 0xFF. */
 	if (max_devfn > 0xff) {
@@ -1549,7 +1557,8 @@ static void pci_bridge_route(struct bus *link, scan_state state)
 		link->subordinate = link->secondary + dev->hotplug_buses;
 		link->max_subordinate = parent->max_subordinate
 						? parent->max_subordinate
-						: (CONFIG_ECAM_MMCONF_BUS_NUMBER - 1);
+						: (PCI_BUSES_PER_SEGMENT_GROUP - 1);
+		link->segment_group = parent->segment_group;
 	}
 
 	if (link->secondary > link->max_subordinate)
diff --git a/src/device/pci_rom.c b/src/device/pci_rom.c
index 2592f83757ed..cc1e5d1277fe 100644
--- a/src/device/pci_rom.c
+++ b/src/device/pci_rom.c
@@ -230,6 +230,10 @@ ati_rom_acpi_fill_vfct(const struct device *device, acpi_vfct_t *vfct_struct,
 		printk(BIOS_ERR, "%s failed\n", __func__);
 		return current;
 	}
+	if (device->bus->segment_group) {
+		printk(BIOS_ERR, "VFCT only supports GPU in first PCI segment group.\n");
+		return current;
+	}
 
 	printk(BIOS_DEBUG, "           Copying %sVBIOS image from %p\n",
 			rom == (struct rom_header *)
diff --git a/src/device/pcix_device.c b/src/device/pcix_device.c
index 5593357fca60..e40ed3bf6570 100644
--- a/src/device/pcix_device.c
+++ b/src/device/pcix_device.c
@@ -110,8 +110,8 @@ void pcix_scan_bridge(struct device *dev)
 		pcix_tune_bus(dev->link_list);
 
 	/* Print the PCI-X bus speed. */
-	printk(BIOS_DEBUG, "PCI: %02x: %s\n", dev->link_list->secondary,
-	       pcix_speed(sstatus));
+	printk(BIOS_DEBUG, "PCI: %02x:%02x: %s\n", dev->link_list->segment_group,
+	       dev->link_list->secondary, pcix_speed(sstatus));
 }
 
 /** Default device operations for PCI-X bridges */