[PATCH v8 0/3] Add Apple T2 NHI Device links

[PATCH v8 0/3] Add Apple T2 NHI Device links

[Atharva Tiwari]

This series adds support for Device linking on Titan ridge, and
Icelake, which are used exclusively on Apple T2 machines.

Changes in v8:
- Shifted tb_apple_add_links to pci.c

Changes in v7:
- Used pci_lock_rescan_remove to prevent race conditons.
- Fixed patch format.

Changes in v6:
- Used for_each_pci_bridge in Icelake section
- Removed has_apple_t2_chip as its not required now

Changes in v5:
- Used Icelake root PCI IDs for detection of root ports instead of TRP

Changes in v4:
- Limited TRP check to T2 Icelake systems only
- Optimized has_apple_t2_chip check
- Included pci.h to drivers/thunderbolt/tb.c
- Used __free(pci_dev_put) to avoid label

Changes in v3:
- Fix build errors with non-x86 machines
- Used __initconst for apple_t2_devices
- Removed UEFI_QUIRK_SKIP_CERT as its unused now
- Used IS_ENABLED(CONFIG_ACPI) in tb_apple_add_links for the T2 part
- Removed !bid check to remove warning with -Waddress

Changes in v2:
- Used a less generic name for has_t2_chip
- Used DMI instead of PCI for has_apple_t2_chip to avoid PCI problems
- Initialized ret in tb_apple_add_links

Link to v7:
https://lore.kernel.org/all/20260812153717.1345-1-atharvatiwarilinuxdev@gmail.com/

Link to v6:
https://lore.kernel.org/all/20260730223435.2874-1-atharvatiwarilinuxdev@gmail.com/

Link to v5:
https://lore.kernel.org/all/20260727211807.1223-1-atharvatiwarilinuxdev@gmail.com/

Link to v4:
https://lore.kernel.org/all/20260724164641.2239-1-atharvatiwarilinuxdev@gmail.com/

Link to v3:
https://lore.kernel.org/all/20260721063412.11588-1-atharvatiwarilinuxdev@gmail.com/

Link to v2:
https://lore.kernel.org/all/20260721054506.11871-1-atharvatiwarilinuxdev@gmail.com/

Link to v1:
https://lore.kernel.org/all/20260719180308.1398-1-atharvatiwarilinuxdev@gmail.com/


Atharva Tiwari (3):
  thunderbolt: Shift tb_apple_add_links to pci.c
  thunderbolt: Add device links for Apple machines with Titan Ridge
  thunderbolt: Add device links for Apple systems with Icelake
    thunderbolt

 drivers/thunderbolt/pci.c | 119 ++++++++++++++++++++++++++++++++++++++
 drivers/thunderbolt/tb.c  |  72 +----------------------
 drivers/thunderbolt/tb.h  |   1 +
 3 files changed, 121 insertions(+), 71 deletions(-)

-- 
2.43.0

[PATCH v8 1/3] thunderbolt: Shift tb_apple_add_links to pci.c

[Atharva Tiwari]

Shift tb_apple_add_links to pci.c as tb_apple_add_links calls
pci functions.

Suggested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Atharva Tiwari <atharvatiwarilinuxdev@gmail.com>
---
 drivers/thunderbolt/pci.c | 73 +++++++++++++++++++++++++++++++++++++++
 drivers/thunderbolt/tb.c  | 72 +-------------------------------------
 drivers/thunderbolt/tb.h  |  1 +
 3 files changed, 75 insertions(+), 71 deletions(-)

diff --git a/drivers/thunderbolt/pci.c b/drivers/thunderbolt/pci.c
index bbd186c29..c3d5a36ab 100644
--- a/drivers/thunderbolt/pci.c
+++ b/drivers/thunderbolt/pci.c
@@ -18,6 +18,7 @@
 #include <linux/property.h>
 #include <linux/string_helpers.h>
 #include <linux/suspend.h>
+#include <linux/platform_data/x86/apple.h>
 
 #include "nhi.h"
 #include "nhi_regs.h"
@@ -261,6 +262,53 @@ static const struct tb_nhi_ops pci_nhi_default_ops = {
 	.init_interrupts = nhi_pci_init_msi,
 };
 
+static bool tb_pci_add_links_discrete(struct pci_dev *nhi_pdev)
+{
+	struct pci_dev *pdev, *upstream = pci_upstream_bridge(nhi_pdev);
+	bool ret = false;
+
+	while (upstream) {
+		if (!pci_is_pcie(upstream))
+			return false;
+		if (pci_pcie_type(upstream) == PCI_EXP_TYPE_UPSTREAM)
+			break;
+		upstream = pci_upstream_bridge(upstream);
+	}
+
+	if (!upstream)
+		return false;
+
+	/*
+	 * For each hotplug downstream port, create add device link
+	 * back to NHI so that PCIe tunnels can be re-established after
+	 * sleep.
+	 */
+	pci_lock_rescan_remove();
+	for_each_pci_bridge(pdev, upstream->subordinate) {
+		const struct device_link *link;
+
+		if (!pci_is_pcie(pdev))
+			continue;
+		if (pci_pcie_type(pdev) != PCI_EXP_TYPE_DOWNSTREAM ||
+		    !pdev->is_pciehp)
+			continue;
+
+		link = device_link_add(&pdev->dev, &nhi_pdev->dev,
+				       DL_FLAG_AUTOREMOVE_SUPPLIER |
+				       DL_FLAG_PM_RUNTIME);
+		if (link) {
+			dev_dbg(&nhi_pdev->dev, "created link from %s\n",
+				dev_name(&pdev->dev));
+			ret = true;
+		} else {
+			dev_warn(&nhi_pdev->dev, "device link creation from %s failed\n",
+				 dev_name(&pdev->dev));
+		}
+	}
+	pci_unlock_rescan_remove();
+
+	return ret;
+}
 /* Ice Lake specific NHI operations */
 
 #define ICL_LC_MAILBOX_TIMEOUT	500 /* ms */
@@ -444,6 +492,31 @@ static const struct tb_nhi_ops icl_nhi_ops = {
 	.init_interrupts = nhi_pci_init_msi,
 };
 
+/*
+ * During suspend the Thunderbolt controller is reset and all PCIe
+ * tunnels are lost. The NHI driver will try to reestablish all tunnels
+ * during resume. This adds device links between the tunneled PCIe
+ * downstream ports and the NHI so that the device core will make sure
+ * NHI is resumed first before the rest.
+ */
+bool tb_pci_add_links(struct tb_nhi *nhi)
+{
+	struct pci_dev *nhi_pdev = to_pci_dev(nhi->dev);
+
+	if (!x86_apple_machine)
+		return false;
+
+	switch (nhi_pdev->device) {
+	case PCI_DEVICE_ID_INTEL_LIGHT_RIDGE:
+	case PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_4C:
+	case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_NHI:
+	case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_NHI:
+		return tb_pci_add_links_discrete(nhi_pdev);
+	default:
+		return false;
+	}
+}
+
 static int nhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	struct device *dev = &pdev->dev;
diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index f43f2d952..9c2fc7ff1 100644
--- a/drivers/thunderbolt/tb.c
+++ b/drivers/thunderbolt/tb.c
@@ -10,7 +10,6 @@
 #include <linux/errno.h>
 #include <linux/delay.h>
 #include <linux/pm_runtime.h>
-#include <linux/platform_data/x86/apple.h>
 
 #include "tb.h"
 #include "tb_regs.h"
@@ -3302,75 +3301,6 @@ static const struct tb_cm_ops tb_cm_ops = {
 	.disconnect_xdomain_paths = tb_disconnect_xdomain_paths,
 };
 
-/*
- * During suspend the Thunderbolt controller is reset and all PCIe
- * tunnels are lost. The NHI driver will try to reestablish all tunnels
- * during resume. This adds device links between the tunneled PCIe
- * downstream ports and the NHI so that the device core will make sure
- * NHI is resumed first before the rest.
- */
-static bool tb_apple_add_links(struct tb_nhi *nhi)
-{
-	struct pci_dev *nhi_pdev = to_pci_dev(nhi->dev);
-	struct pci_dev *upstream, *pdev;
-	bool ret;
-
-	if (!x86_apple_machine)
-		return false;
-
-	switch (nhi_pdev->device) {
-	case PCI_DEVICE_ID_INTEL_LIGHT_RIDGE:
-	case PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_4C:
-	case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_NHI:
-	case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_NHI:
-		break;
-	default:
-		return false;
-	}
-
-	upstream = pci_upstream_bridge(nhi_pdev);
-	while (upstream) {
-		if (!pci_is_pcie(upstream))
-			return false;
-		if (pci_pcie_type(upstream) == PCI_EXP_TYPE_UPSTREAM)
-			break;
-		upstream = pci_upstream_bridge(upstream);
-	}
-
-	if (!upstream)
-		return false;
-
-	/*
-	 * For each hotplug downstream port, create add device link
-	 * back to NHI so that PCIe tunnels can be re-established after
-	 * sleep.
-	 */
-	ret = false;
-	for_each_pci_bridge(pdev, upstream->subordinate) {
-		const struct device_link *link;
-
-		if (!pci_is_pcie(pdev))
-			continue;
-		if (pci_pcie_type(pdev) != PCI_EXP_TYPE_DOWNSTREAM ||
-		    !pdev->is_pciehp)
-			continue;
-
-		link = device_link_add(&pdev->dev, nhi->dev,
-				       DL_FLAG_AUTOREMOVE_SUPPLIER |
-				       DL_FLAG_PM_RUNTIME);
-		if (link) {
-			dev_dbg(nhi->dev, "created link from %s\n",
-				dev_name(&pdev->dev));
-			ret = true;
-		} else {
-			dev_warn(nhi->dev, "device link creation from %s failed\n",
-				 dev_name(&pdev->dev));
-		}
-	}
-
-	return ret;
-}
-
 struct tb *tb_probe(struct tb_nhi *nhi)
 {
 	struct tb_cm *tcm;
@@ -3400,7 +3330,7 @@ struct tb *tb_probe(struct tb_nhi *nhi)
 	 * before the PCIe/USB stack is resumed so complain here if we
 	 * found them missing.
 	 */
-	if (!tb_apple_add_links(nhi) && !tb_acpi_add_links(nhi))
+	if (!tb_pci_add_links(nhi) && !tb_acpi_add_links(nhi))
 		tb_warn(tb, "device links to tunneled native ports are missing!\n");
 
 	return tb;
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index ec9192b61..6a285fe7f 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -1506,6 +1506,7 @@ static inline bool usb4_port_device_is_offline(const struct usb4_port *usb4)
 }
 
 void tb_check_quirks(struct tb_switch *sw);
+bool tb_pci_add_links(struct tb_nhi *nhi);
 
 #ifdef CONFIG_ACPI
 bool tb_acpi_add_links(struct tb_nhi *nhi);
-- 
2.43.0

[PATCH v8 2/3] thunderbolt: Add device links for Apple machines with Titan Ridge

[Atharva Tiwari]

Add device links for Apple machines with the
Titan Ridge thunderbolt controller.

To add device links on Titan ridge, the discrete method is used.

Signed-off-by: Atharva Tiwari <atharvatiwarilinuxdev@gmail.com>
---
 drivers/thunderbolt/pci.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/thunderbolt/pci.c b/drivers/thunderbolt/pci.c
index c3d5a36ab..af3a7a9ba 100644
--- a/drivers/thunderbolt/pci.c
+++ b/drivers/thunderbolt/pci.c
@@ -511,6 +511,8 @@ bool tb_pci_add_links(struct tb_nhi *nhi)
 	case PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_4C:
 	case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_NHI:
 	case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_NHI:
+	case PCI_DEVICE_ID_INTEL_TITAN_RIDGE_2C_NHI:
+	case PCI_DEVICE_ID_INTEL_TITAN_RIDGE_4C_NHI:
 		return tb_pci_add_links_discrete(nhi_pdev);
 	default:
 		return false;
-- 
2.43.0

[PATCH v8 3/3] thunderbolt: Add device links for Apple systems with Icelake thunderbolt

[Atharva Tiwari]

Ice Lake Thunderbolt NHI That are on some Macs. The NHI and its
associated PCIe Root Ports all sit directly on the Root Complex
with no upstream port. Identify the tunneled PCIe Root Ports by
their PCI IDs and create device links back to the NHI so that
PCIe tunnels can be re-established after sleep.

Tested-by: Alexander Fischer <alexander.fischer@kait2en.org>

Co-developed-by: Andre Eikmeyer <andre@negmaster.com>
Signed-off-by: Andre Eikmeyer <andre@negmaster.com>

Signed-off-by: Atharva Tiwari <atharvatiwarilinuxdev@gmail.com>
---
 drivers/thunderbolt/pci.c | 44 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/drivers/thunderbolt/pci.c b/drivers/thunderbolt/pci.c
index af3a7a9ba..8c0e40fb9 100644
--- a/drivers/thunderbolt/pci.c
+++ b/drivers/thunderbolt/pci.c
@@ -492,6 +492,47 @@ static const struct tb_nhi_ops icl_nhi_ops = {
 	.init_interrupts = nhi_pci_init_msi,
 };
 
+static bool tb_pci_add_links_icl(struct pci_dev *nhi_pdev)
+{
+	struct pci_dev *pdev;
+	const struct device_link *link;
+	bool ret = false;
+
+	pci_lock_rescan_remove();
+	for_each_pci_bridge(pdev, nhi_pdev->bus) {
+		if (!pci_is_pcie(pdev) ||
+		    pci_pcie_type(pdev) != PCI_EXP_TYPE_ROOT_PORT)
+			continue;
+
+		switch (pdev->device) {
+		/* Ice Lake Thunderbolt 3 PCIe Root Ports */
+		case 0x8a1d:
+		case 0x8a1f:
+		case 0x8a21:
+		case 0x8a23:
+			break;
+		default:
+			continue;
+		}
+
+		link = device_link_add(&pdev->dev, &nhi_pdev->dev,
+				       DL_FLAG_AUTOREMOVE_SUPPLIER |
+				       DL_FLAG_PM_RUNTIME);
+		if (link) {
+			dev_dbg(&nhi_pdev->dev, "created link from %s\n",
+				dev_name(&pdev->dev));
+			ret = true;
+		} else {
+			dev_warn(&nhi_pdev->dev,
+				 "device link creation from %s failed\n",
+				 dev_name(&pdev->dev));
+		}
+	}
+	pci_unlock_rescan_remove();
+
+	return ret;
+}
+
 /*
  * During suspend the Thunderbolt controller is reset and all PCIe
  * tunnels are lost. The NHI driver will try to reestablish all tunnels
@@ -514,6 +555,9 @@ bool tb_pci_add_links(struct tb_nhi *nhi)
 	case PCI_DEVICE_ID_INTEL_TITAN_RIDGE_2C_NHI:
 	case PCI_DEVICE_ID_INTEL_TITAN_RIDGE_4C_NHI:
 		return tb_pci_add_links_discrete(nhi_pdev);
+	case PCI_DEVICE_ID_INTEL_ICL_NHI0:
+	case PCI_DEVICE_ID_INTEL_ICL_NHI1:
+		return tb_pci_add_links_icl(nhi_pdev);
 	default:
 		return false;
 	}
-- 
2.43.0