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

[PATCH 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.

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

 arch/x86/pci/fixup.c                          | 10 ++++
 drivers/thunderbolt/tb.c                      | 49 +++++++++++++++++++
 include/linux/platform_data/x86/apple.h       |  5 ++
 security/integrity/platform_certs/load_uefi.c | 38 +++-----------
 4 files changed, 72 insertions(+), 30 deletions(-)

-- 
2.43.0

[PATCH 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/pci/fixup.c                          | 10 +++++
 include/linux/platform_data/x86/apple.h       |  5 +++
 security/integrity/platform_certs/load_uefi.c | 38 ++++---------------
 3 files changed, 23 insertions(+), 30 deletions(-)

diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
index b301c6c8df75..fbd204ca4c6d 100644
--- a/arch/x86/pci/fixup.c
+++ b/arch/x86/pci/fixup.c
@@ -7,6 +7,7 @@
 #include <linux/delay.h>
 #include <linux/dmi.h>
 #include <linux/pci.h>
+#include <linux/platform_data/x86/apple.h>
 #include <linux/suspend.h>
 #include <linux/vgaarb.h>
 #include <asm/amd/node.h>
@@ -995,6 +996,15 @@ static void asus_disable_nvme_d3cold(struct pci_dev *pdev)
 }
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x9a09, asus_disable_nvme_d3cold);
 
+bool has_t2_chip;
+EXPORT_SYMBOL(has_t2_chip);
+
+static void apple_has_t2_chip(struct pci_dev *pdev)
+{
+	has_t2_chip = true;
+}
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_APPLE, 0x1801, apple_has_t2_chip);
+
 #ifdef CONFIG_SUSPEND
 /*
  * Root Ports on some AMD SoCs advertise PME_Support for D3hot and D3cold, but
diff --git a/include/linux/platform_data/x86/apple.h b/include/linux/platform_data/x86/apple.h
index 079e816c3c21..a2ab63bd1eac 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_t2_chip - whether the machine has the Apple T2 chip
+ */
+extern bool has_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..da57ac322e72 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_t2_chip) {
 		pr_err("Reading UEFI Secure Boot Certs is not supported on T2 Macs.\n");
 		return false;
 	}
-- 
2.43.0

[PATCH 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 | 49 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index c69c323e6952..26529141573a 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>
@@ -3310,6 +3311,54 @@ static bool tb_apple_add_links(struct tb_nhi *nhi)
 	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_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