[PATCH v2 0/2] Add Apple T2 NHI device links

[PATCH v2 0/2] Add Apple T2 NHI device links

[Atharva Tiwari]

This series adds a cached flag to detect Apple T2 systems, then uses it
to create device links for the Thunderbolt NHI.

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

Atharva Tiwari (2):
  treewide: Add a flag to detect the Apple T2 chip
  thunderbolt: Add device links for Apple T2 NHI

 arch/x86/kernel/quirks.c                      | 105 ++++++++++++++++++
 drivers/thunderbolt/tb.c                      |  51 ++++++++-
 include/linux/platform_data/x86/apple.h       |   5 +
 security/integrity/platform_certs/load_uefi.c |  38 ++-----
 4 files changed, 168 insertions(+), 31 deletions(-)

-- 
2.43.0

[PATCH v2 1/2] treewide: Add a flag to detect the Apple T2 chip

[Atharva Tiwari]

Add a flag to detect Apple T2 chips on Intel Macs.
Cache the result to avoid repeated checks. That will
be used in upcoming patches.

Signed-off-by: Atharva Tiwari <atharvatiwarilinuxdev@gmail.com>
---
 arch/x86/kernel/quirks.c                      | 105 ++++++++++++++++++
 include/linux/platform_data/x86/apple.h       |   5 +
 security/integrity/platform_certs/load_uefi.c |  38 ++-----
 3 files changed, 118 insertions(+), 30 deletions(-)

diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
index a92f18db9610..74b29738d404 100644
--- a/arch/x86/kernel/quirks.c
+++ b/arch/x86/kernel/quirks.c
@@ -664,8 +664,113 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2083, quirk_intel_purley_xeon_ras
 bool x86_apple_machine;
 EXPORT_SYMBOL(x86_apple_machine);
 
+bool has_apple_t2_chip;
+EXPORT_SYMBOL(has_apple_t2_chip);
+
+static const struct dmi_system_id apple_t2_devices[] = {
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro15,1"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro15,2"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro15,3"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro15,4"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro16,1"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro16,2"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro16,3"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro16,4"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookAir8,1"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookAir8,2"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookAir9,1"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Macmini8,1"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacPro7,1"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "iMac20,1"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "iMac20,2"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "iMacPro1,1"),
+		},
+	},
+	{ }
+};
+
 void __init early_platform_quirks(void)
 {
 	x86_apple_machine = dmi_match(DMI_SYS_VENDOR, "Apple Inc.") ||
 			    dmi_match(DMI_SYS_VENDOR, "Apple Computer, Inc.");
+
+	has_apple_t2_chip = dmi_check_system(apple_t2_devices);
 }
diff --git a/include/linux/platform_data/x86/apple.h b/include/linux/platform_data/x86/apple.h
index 079e816c3c21..50bbcc5134fc 100644
--- a/include/linux/platform_data/x86/apple.h
+++ b/include/linux/platform_data/x86/apple.h
@@ -6,8 +6,13 @@
  * x86_apple_machine - whether the machine is an x86 Apple Macintosh
  */
 extern bool x86_apple_machine;
+/**
+ * has_apple_t2_chip - whether the machine has the Apple T2 chip
+ */
+extern bool has_apple_t2_chip;
 #else
 #define x86_apple_machine false
+#define has_t2_chip false
 #endif
 
 #endif
diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c
index c0d6948446c3..b4096d4c828d 100644
--- a/security/integrity/platform_certs/load_uefi.c
+++ b/security/integrity/platform_certs/load_uefi.c
@@ -3,42 +3,16 @@
 #include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/cred.h>
-#include <linux/dmi.h>
 #include <linux/err.h>
 #include <linux/efi.h>
 #include <linux/slab.h>
 #include <linux/ima.h>
+#include <linux/platform_data/x86/apple.h>
 #include <keys/asymmetric-type.h>
 #include <keys/system_keyring.h>
 #include "../integrity.h"
 #include "keyring_handler.h"
 
-/*
- * On T2 Macs reading the db and dbx efi variables to load UEFI Secure Boot
- * certificates causes occurrence of a page fault in Apple's firmware and
- * a crash disabling EFI runtime services. The following quirk skips reading
- * these variables.
- */
-static const struct dmi_system_id uefi_skip_cert[] = {
-	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro15,1") },
-	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro15,2") },
-	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro15,3") },
-	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro15,4") },
-	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro16,1") },
-	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro16,2") },
-	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro16,3") },
-	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro16,4") },
-	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookAir8,1") },
-	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookAir8,2") },
-	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookAir9,1") },
-	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "Macmini8,1") },
-	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacPro7,1") },
-	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "iMac20,1") },
-	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "iMac20,2") },
-	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "iMacPro1,1") },
-	{ }
-};
-
 /*
  * Look to see if a UEFI variable called MokIgnoreDB exists and return true if
  * it does.
@@ -165,10 +139,14 @@ static int __init load_uefi_certs(void)
 	unsigned long dbsize = 0, dbxsize = 0, mokxsize = 0;
 	efi_status_t status;
 	int rc = 0;
-	const struct dmi_system_id *dmi_id;
 
-	dmi_id = dmi_first_match(uefi_skip_cert);
-	if (dmi_id) {
+	/*
+	 * On T2 Macs reading the db and dbx efi variables to load UEFI Secure Boot
+	 * certificates causes occurrence of a page fault in Apple's firmware and
+	 * a crash disabling EFI runtime services. The following quirk skips reading
+	 * these variables.
+	 */
+	if (has_apple_t2_chip) {
 		pr_err("Reading UEFI Secure Boot Certs is not supported on T2 Macs.\n");
 		return false;
 	}
-- 
2.43.0

[PATCH v2 2/2] thunderbolt: Add device links for Apple T2 NHI

[Atharva Tiwari]

From: Andre Eikmeyer <andre@negmaster.com>

Thunderbolt NHI on T2 Macs (2018-2020). The NHI and its
associated PCIe root ports all sit directly on the root complex
with no upstream port. Apple's ACPI tables name Thunderbolt root
ports as TRP0, TRP1, etc. Find them and create device links back
to the NHI so that PCIe tunnels can be re-established after sleep.

Co-developed-by: Atharva Tiwari <atharvatiwarilinuxdev@gmail.com>
Signed-off-by: Atharva Tiwari <atharvatiwarilinuxdev@gmail.com>

Signed-off-by: Andre Eikmeyer <andre@negmaster.com>
---
 drivers/thunderbolt/tb.c | 51 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 50 insertions(+), 1 deletion(-)

diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index c69c323e6952..ca47bfbcefdf 100644
--- a/drivers/thunderbolt/tb.c
+++ b/drivers/thunderbolt/tb.c
@@ -6,6 +6,7 @@
  * Copyright (C) 2019, Intel Corporation
  */
 
+#include <linux/acpi.h>
 #include <linux/slab.h>
 #include <linux/errno.h>
 #include <linux/delay.h>
@@ -3305,11 +3306,59 @@ static const struct tb_cm_ops tb_cm_ops = {
 static bool tb_apple_add_links(struct tb_nhi *nhi)
 {
 	struct pci_dev *upstream, *pdev;
-	bool ret;
+	bool ret = false;
 
 	if (!x86_apple_machine)
 		return false;
 
+	/* On T2 Macs. the root ports are stored in ACPI as TRP0,
+	 * TRP1, etc. Find them and create device links
+	 * so that PCIe tunnels can be re-established after
+	 * sleep.
+	 */
+	if (has_apple_t2_chip) {
+		struct acpi_device *adev;
+		unsigned int slot, func;
+		const struct device_link *link;
+		const char *bid;
+
+		for (slot = 0; slot < 32; slot++) {
+			for (func = 0; func < 8; func++) {
+				pdev = pci_get_slot(nhi->pdev->bus, PCI_DEVFN(slot, func));
+				if (!pdev)
+					continue;
+
+				if (!pci_is_pcie(pdev) || pci_pcie_type(pdev) !=
+						PCI_EXP_TYPE_ROOT_PORT)
+					goto put_pdev;
+
+				adev = ACPI_COMPANION(&pdev->dev);
+				if (!adev)
+					goto put_pdev;
+
+				bid = acpi_device_bid(adev);
+				if (!bid || strncmp(bid, "TRP", 3) != 0)
+					goto put_pdev;
+
+				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));
+
+put_pdev:
+	pci_dev_put(pdev);
+			}
+		}
+		return ret;
+	}
+
 	switch (nhi->pdev->device) {
 	case PCI_DEVICE_ID_INTEL_LIGHT_RIDGE:
 	case PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_4C:
-- 
2.43.0

Re: [PATCH v2 1/2] treewide: Add a flag to detect the Apple T2 chip

[Jarkko Sakkinen]

On Tue, Jul 21, 2026 at 01:45:01AM -0400, Atharva Tiwari wrote:
> Add a flag to detect Apple T2 chips on Intel Macs.
> Cache the result to avoid repeated checks. That will
> be used in upcoming patches.
> 
> Signed-off-by: Atharva Tiwari <atharvatiwarilinuxdev@gmail.com>
> ---
>  arch/x86/kernel/quirks.c                      | 105 ++++++++++++++++++
>  include/linux/platform_data/x86/apple.h       |   5 +
>  security/integrity/platform_certs/load_uefi.c |  38 ++-----
>  3 files changed, 118 insertions(+), 30 deletions(-)
> 
> diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
> index a92f18db9610..74b29738d404 100644
> --- a/arch/x86/kernel/quirks.c
> +++ b/arch/x86/kernel/quirks.c
> @@ -664,8 +664,113 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2083, quirk_intel_purley_xeon_ras
>  bool x86_apple_machine;
>  EXPORT_SYMBOL(x86_apple_machine);
>  
> +bool has_apple_t2_chip;
> +EXPORT_SYMBOL(has_apple_t2_chip);
> +
> +static const struct dmi_system_id apple_t2_devices[] = {
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro15,1"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro15,2"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro15,3"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro15,4"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro16,1"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro16,2"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro16,3"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro16,4"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookAir8,1"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookAir8,2"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookAir9,1"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Macmini8,1"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "MacPro7,1"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "iMac20,1"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "iMac20,2"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "iMacPro1,1"),
> +		},
> +	},
> +	{ }
> +};
> +
>  void __init early_platform_quirks(void)
>  {
>  	x86_apple_machine = dmi_match(DMI_SYS_VENDOR, "Apple Inc.") ||
>  			    dmi_match(DMI_SYS_VENDOR, "Apple Computer, Inc.");
> +
> +	has_apple_t2_chip = dmi_check_system(apple_t2_devices);
>  }
> diff --git a/include/linux/platform_data/x86/apple.h b/include/linux/platform_data/x86/apple.h
> index 079e816c3c21..50bbcc5134fc 100644
> --- a/include/linux/platform_data/x86/apple.h
> +++ b/include/linux/platform_data/x86/apple.h
> @@ -6,8 +6,13 @@
>   * x86_apple_machine - whether the machine is an x86 Apple Macintosh
>   */
>  extern bool x86_apple_machine;
> +/**
> + * has_apple_t2_chip - whether the machine has the Apple T2 chip
> + */
> +extern bool has_apple_t2_chip;
>  #else
>  #define x86_apple_machine false
> +#define has_t2_chip false
>  #endif
>  
>  #endif
> diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c
> index c0d6948446c3..b4096d4c828d 100644
> --- a/security/integrity/platform_certs/load_uefi.c
> +++ b/security/integrity/platform_certs/load_uefi.c
> @@ -3,42 +3,16 @@
>  #include <linux/kernel.h>
>  #include <linux/sched.h>
>  #include <linux/cred.h>
> -#include <linux/dmi.h>
>  #include <linux/err.h>
>  #include <linux/efi.h>
>  #include <linux/slab.h>
>  #include <linux/ima.h>
> +#include <linux/platform_data/x86/apple.h>
>  #include <keys/asymmetric-type.h>
>  #include <keys/system_keyring.h>
>  #include "../integrity.h"
>  #include "keyring_handler.h"
>  
> -/*
> - * On T2 Macs reading the db and dbx efi variables to load UEFI Secure Boot
> - * certificates causes occurrence of a page fault in Apple's firmware and
> - * a crash disabling EFI runtime services. The following quirk skips reading
> - * these variables.
> - */
> -static const struct dmi_system_id uefi_skip_cert[] = {
> -	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro15,1") },
> -	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro15,2") },
> -	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro15,3") },
> -	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro15,4") },
> -	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro16,1") },
> -	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro16,2") },
> -	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro16,3") },
> -	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookPro16,4") },
> -	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookAir8,1") },
> -	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookAir8,2") },
> -	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacBookAir9,1") },
> -	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "Macmini8,1") },
> -	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "MacPro7,1") },
> -	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "iMac20,1") },
> -	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "iMac20,2") },
> -	{ UEFI_QUIRK_SKIP_CERT("Apple Inc.", "iMacPro1,1") },
> -	{ }
> -};
> -
>  /*
>   * Look to see if a UEFI variable called MokIgnoreDB exists and return true if
>   * it does.
> @@ -165,10 +139,14 @@ static int __init load_uefi_certs(void)
>  	unsigned long dbsize = 0, dbxsize = 0, mokxsize = 0;
>  	efi_status_t status;
>  	int rc = 0;
> -	const struct dmi_system_id *dmi_id;
>  
> -	dmi_id = dmi_first_match(uefi_skip_cert);
> -	if (dmi_id) {
> +	/*
> +	 * On T2 Macs reading the db and dbx efi variables to load UEFI Secure Boot
> +	 * certificates causes occurrence of a page fault in Apple's firmware and
> +	 * a crash disabling EFI runtime services. The following quirk skips reading
> +	 * these variables.
> +	 */
> +	if (has_apple_t2_chip) {
>  		pr_err("Reading UEFI Secure Boot Certs is not supported on T2 Macs.\n");
>  		return false;
>  	}
> -- 
> 2.43.0
> 

Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>

BR, Jarkko