From e2e360e3f8ab90154bbad05ef5d9cb480d841dca Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jeremy@system76.com>
Date: Wed, 9 Oct 2019 21:28:04 -0600
Subject: [PATCH] Add hotplug_buses to device struct to allow removal of hack

---
 src/device/pci_device.c               | 24 ++++++++++++++++--------
 src/drivers/thunderbolt/thunderbolt.c | 19 +++++++++++++++----
 src/include/device/device.h           |  1 +
 3 files changed, 32 insertions(+), 12 deletions(-)

diff --git a/src/device/pci_device.c b/src/device/pci_device.c
index 861ed4a924..29ef5dd8bd 100644
--- a/src/device/pci_device.c
+++ b/src/device/pci_device.c
@@ -1217,13 +1217,15 @@ static void pci_bridge_route(struct bus *link, scan_state state)
 
 	if (state == PCI_ROUTE_SCAN) {
 		link->secondary = parent->subordinate + 1;
-		link->subordinate = link->secondary;
-
-		if (dev->vendor == 0x8086 && dev->device == 0x15e7 && PCI_SLOT(dev->path.pci.devfn) == 1) {
-			printk(BIOS_DEBUG, "system76: HACK: add 32 to subordinate\n");
-			link->subordinate += 32;
-		}
-		printk(BIOS_DEBUG, "system76: pci_bridge_route: assigning link secondary %d subordinate %d\n", link->secondary, link->subordinate);
+		link->subordinate = link->secondary + dev->hotplug_buses;
+		printk(
+			BIOS_DEBUG,
+			"system76: %s: %s: assigning link secondary %d subordinate %d\n",
+			__func__,
+			dev_path(dev),
+			link->secondary,
+			link->subordinate
+		);
 	}
 
 	if (state == PCI_ROUTE_CLOSE) {
@@ -1259,7 +1261,13 @@ static void pci_bridge_route(struct bus *link, scan_state state)
 	if (state == PCI_ROUTE_FINAL) {
 		pci_write_config16(dev, PCI_COMMAND, link->bridge_cmd);
 		parent->subordinate = link->subordinate;
-		printk(BIOS_DEBUG, "system76: pci_bridge_route: assigning link subordinate %d\n", link->subordinate);
+		printk(
+			BIOS_DEBUG,
+			"system76: %s: %s: assigning parent subordinate %d\n",
+			__func__,
+			dev_path(dev),
+			parent->subordinate
+		);
 	}
 }
 
diff --git a/src/drivers/thunderbolt/thunderbolt.c b/src/drivers/thunderbolt/thunderbolt.c
index c1ef3c7bb3..cb417ec5b8 100644
--- a/src/drivers/thunderbolt/thunderbolt.c
+++ b/src/drivers/thunderbolt/thunderbolt.c
@@ -52,15 +52,26 @@ static struct device_operations slot_dev_ops = {
 	.read_resources   = slot_dev_read_resources,
 };
 
+static bool tbt_is_hotplug_bridge(struct device *dev) {
+	return PCI_SLOT(dev->path.pci.devfn) == 1;
+}
+
 static void tbt_pciexp_scan_bridge(struct device *dev) {
-	printk(BIOS_DEBUG, "tbt_pciexp_scan_bridge %s: scan bridge\n", dev_path(dev));
+	printk(BIOS_DEBUG, "%s: %s: scan bridge\n", __func__, dev_path(dev));
+
+	bool is_hotplug = tbt_is_hotplug_bridge(dev);
+	if (is_hotplug) {
+		/* Add hotplug buses, must happen before bus scan */
+		printk(BIOS_DEBUG, "%s: %s: add hotplug buses\n", __func__, dev_path(dev));
+		dev->hotplug_buses = 32;
+	}
 
 	/* Normal PCIe Scan */
 	pciexp_scan_bridge(dev);
 
-	/* Add dummy slot to preserve resources */
-	if (PCI_SLOT(dev->path.pci.devfn) == 1) {
-		printk(BIOS_DEBUG, "tbt_pciexp_scan_bridge %s: add dummy device\n", dev_path(dev));
+	if (is_hotplug) {
+		/* Add dummy slot to preserve resources, must happen after bus scan */
+		printk(BIOS_DEBUG, "%s: %s: add dummy device\n", __func__, dev_path(dev));
 		struct device *slot;
 		struct device_path slot_path = { .type = DEVICE_PATH_NONE };
 		slot = alloc_dev(dev->link_list, &slot_path);
diff --git a/src/include/device/device.h b/src/include/device/device.h
index cb37c096e4..f22bed5d58 100644
--- a/src/include/device/device.h
+++ b/src/include/device/device.h
@@ -129,6 +129,7 @@ struct device {
 	unsigned int    disable_pcie_aspm : 1;
 	unsigned int    hidden : 1;	/* set if we should hide from UI */
 	u8 command;
+	uint16_t hotplug_buses; /* hotplug buses to allocate */
 
 	/* Base registers for this device. I/O, MEM and Expansion ROM */
 	DEVTREE_CONST struct resource *resource_list;