[PATCH] efi/cper: Add NVIDIA CPER section support

[Kai-Heng Feng <kaihengf@nvidia.com>]

Add support for decoding NVIDIA-specific error sections in UEFI CPER
records. NVIDIA hardware generates vendor-specific CPER sections
containing error signatures and diagnostic register dumps. This
implementation decodes these sections and prints error details to the
kernel log.

The NVIDIA CPER section contains a fixed header with error metadata
(signature, error type, severity, socket) followed by variable-length
register address-value pairs for hardware diagnostics.

This work is based on libcper [0].

Example output:
Hardware error from APEI Generic Hardware Error Source: 816
event severity: info
 imprecise tstamp: 2025-11-17 07:57:38
 Error 0, type: info
  section_type: NVIDIA, error_data_length: 224
  signature: HSS-IDLE
  error_type: 0
  error_instance: 0
  severity: 0
  socket: 255
  number_regs: 12
  instance_base: 0x0000000000000000
  register[0]: address=0x0000000004f10008 value=0x0000000000002019
  register[1]: address=0x0000000000000000 value=0x0000000000000000

[0] https://github.com/openbmc/libcper/commit/683e055061ce
Signed-off-by: Kai-Heng Feng <kaihengf@nvidia.com>
---
 drivers/firmware/efi/Kconfig       | 16 ++++++
 drivers/firmware/efi/Makefile      |  1 +
 drivers/firmware/efi/cper-nvidia.c | 79 ++++++++++++++++++++++++++++++
 drivers/firmware/efi/cper-nvidia.h | 33 +++++++++++++
 drivers/firmware/efi/cper.c        |  3 ++
 include/linux/cper.h               |  4 ++
 6 files changed, 136 insertions(+)
 create mode 100644 drivers/firmware/efi/cper-nvidia.c
 create mode 100644 drivers/firmware/efi/cper-nvidia.h

diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig
index 29e0729299f5..ed1f53b8e878 100644
--- a/drivers/firmware/efi/Kconfig
+++ b/drivers/firmware/efi/Kconfig
@@ -329,6 +329,22 @@ config UEFI_CPER_X86
 	depends on UEFI_CPER && X86
 	default y
 
+config UEFI_CPER_NVIDIA
+	bool "UEFI CPER NVIDIA support"
+	depends on UEFI_CPER
+	help
+	  This option enables support for decoding NVIDIA-specific error
+	  sections in UEFI Common Platform Error Records (CPER). These
+	  sections contain additional diagnostic information for errors
+	  occurring in NVIDIA hardware such as GPUs, switches, and other
+	  devices.
+
+	  The NVIDIA CPER sections include error signatures (e.g., PCIe-DPC,
+	  DCC-ECC, GPU-STATUS) and diagnostic registers that provide detailed
+	  information about hardware errors for debugging and analysis.
+
+	  If unsure, say N.
+
 config TEE_STMM_EFI
 	tristate "TEE-based EFI runtime variable service driver"
 	depends on EFI && OPTEE
diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile
index 8efbcf699e4f..a571b6086860 100644
--- a/drivers/firmware/efi/Makefile
+++ b/drivers/firmware/efi/Makefile
@@ -42,5 +42,6 @@ obj-$(CONFIG_EFI_CAPSULE_LOADER)	+= capsule-loader.o
 obj-$(CONFIG_EFI_EARLYCON)		+= earlycon.o
 obj-$(CONFIG_UEFI_CPER_ARM)		+= cper-arm.o
 obj-$(CONFIG_UEFI_CPER_X86)		+= cper-x86.o
+obj-$(CONFIG_UEFI_CPER_NVIDIA)		+= cper-nvidia.o
 obj-$(CONFIG_UNACCEPTED_MEMORY)		+= unaccepted_memory.o
 obj-$(CONFIG_TEE_STMM_EFI)		+= stmm/tee_stmm_efi.o
diff --git a/drivers/firmware/efi/cper-nvidia.c b/drivers/firmware/efi/cper-nvidia.c
new file mode 100644
index 000000000000..8f96318c8e95
--- /dev/null
+++ b/drivers/firmware/efi/cper-nvidia.c
@@ -0,0 +1,79 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * UEFI Common Platform Error Record (CPER) support for NVIDIA sections
+ *
+ * Copyright (c) 2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+ */
+
+#include <linux/kernel.h>
+#include <linux/cper.h>
+#include <linux/unaligned.h>
+#include <acpi/ghes.h>
+#include "cper-nvidia.h"
+
+static void cper_print_nvidia_error(const char *pfx,
+				    const struct cper_sec_nvidia *nvidia_err,
+				    size_t error_data_length)
+{
+	int i;
+	const u8 *reg_data;
+	size_t min_size;
+
+	printk("%s""signature: %.16s\n", pfx, nvidia_err->signature);
+	printk("%s""error_type: %u\n", pfx, le16_to_cpu(nvidia_err->error_type));
+	printk("%s""error_instance: %u\n", pfx, le16_to_cpu(nvidia_err->error_instance));
+	printk("%s""severity: %u\n", pfx, nvidia_err->severity);
+	printk("%s""socket: %u\n", pfx, nvidia_err->socket);
+	printk("%s""number_regs: %u\n", pfx, nvidia_err->number_regs);
+	printk("%s""instance_base: 0x%016llx\n", pfx,
+	       (unsigned long long)le64_to_cpu(nvidia_err->instance_base));
+
+	if (nvidia_err->number_regs == 0)
+		return;
+
+	/*
+	 * Validate that all registers fit within the error_data_length.
+	 * Each register pair is 16 bytes (two u64s).
+	 */
+	min_size = sizeof(*nvidia_err) + (nvidia_err->number_regs * 16);
+	if (error_data_length < min_size) {
+		printk("%s""NVIDIA: Invalid number_regs %u (section size %zu, need %zu)\n",
+		       pfx, nvidia_err->number_regs, error_data_length, min_size);
+		return;
+	}
+
+	/*
+	 * Registers are stored as address-value pairs immediately
+	 * following the fixed header. Each pair is two little-endian u64s.
+	 */
+	reg_data = (const u8 *)(nvidia_err + 1);
+	for (i = 0; i < nvidia_err->number_regs; i++) {
+		u64 addr = get_unaligned_le64(reg_data + i * 16);
+		u64 val = get_unaligned_le64(reg_data + i * 16 + 8);
+
+		printk("%s""register[%d]: address=0x%016llx value=0x%016llx\n",
+		       pfx, i, (unsigned long long)addr, (unsigned long long)val);
+	}
+}
+
+void cper_estatus_print_nvidia(const char *pfx,
+			       const struct acpi_hest_generic_data *gdata)
+{
+	struct cper_sec_nvidia *nvidia_err;
+
+	nvidia_err = acpi_hest_get_payload((struct acpi_hest_generic_data *)gdata);
+	if (!nvidia_err) {
+		printk("%s""NVIDIA error: Failed to get payload\n", pfx);
+		return;
+	}
+
+	printk("%s""section_type: NVIDIA, error_data_length: %u\n", pfx, gdata->error_data_length);
+
+	if (gdata->error_data_length < sizeof(*nvidia_err)) {
+		printk("%s""NVIDIA error: Section too small (%u < %zu)\n",
+		       pfx, gdata->error_data_length, sizeof(*nvidia_err));
+		return;
+	}
+
+	cper_print_nvidia_error(pfx, nvidia_err, gdata->error_data_length);
+}
diff --git a/drivers/firmware/efi/cper-nvidia.h b/drivers/firmware/efi/cper-nvidia.h
new file mode 100644
index 000000000000..c489f8f05f0f
--- /dev/null
+++ b/drivers/firmware/efi/cper-nvidia.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * UEFI Common Platform Error Record (CPER) support for NVIDIA sections
+ *
+ * Copyright (c) 2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+ */
+
+#ifndef LINUX_CPER_NVIDIA_H
+#define LINUX_CPER_NVIDIA_H
+
+#include <linux/cper.h>
+
+struct cper_sec_nvidia {
+	char signature[16];
+	__le16 error_type;
+	__le16 error_instance;
+	u8 severity;
+	u8 socket;
+	u8 number_regs;
+	u8 reserved;
+	__le64 instance_base;
+} __packed;
+
+#ifdef CONFIG_UEFI_CPER_NVIDIA
+struct acpi_hest_generic_data;
+void cper_estatus_print_nvidia(const char *pfx,
+			       const struct acpi_hest_generic_data *gdata);
+#else
+static inline void cper_estatus_print_nvidia(const char *pfx,
+					     const struct acpi_hest_generic_data *gdata) { }
+#endif
+
+#endif
diff --git a/drivers/firmware/efi/cper.c b/drivers/firmware/efi/cper.c
index 06b4fdb59917..0b5216aaa8c4 100644
--- a/drivers/firmware/efi/cper.c
+++ b/drivers/firmware/efi/cper.c
@@ -26,6 +26,7 @@
 #include <acpi/ghes.h>
 #include <ras/ras_event.h>
 #include <cxl/event.h>
+#include "cper-nvidia.h"
 
 /*
  * CPER record ID need to be unique even after reboot, because record
@@ -697,6 +698,8 @@ cper_estatus_print_section(const char *pfx, struct acpi_hest_generic_data *gdata
 			cxl_cper_print_prot_err(newpfx, prot_err);
 		else
 			goto err_section_too_small;
+	} else if (guid_equal(sec_type, &CPER_SEC_NVIDIA)) {
+		cper_estatus_print_nvidia(newpfx, gdata);
 	} else {
 		const void *err = acpi_hest_get_payload(gdata);
 
diff --git a/include/linux/cper.h b/include/linux/cper.h
index 440b35e459e5..b5790e48fbef 100644
--- a/include/linux/cper.h
+++ b/include/linux/cper.h
@@ -224,6 +224,10 @@ enum {
 #define CPER_SEC_DMAR_IOMMU						\
 	GUID_INIT(0x036F84E1, 0x7F37, 0x428c, 0xA7, 0x9E, 0x57, 0x5F,	\
 		  0xDF, 0xAA, 0x84, 0xEC)
+/* NVIDIA Error Section */
+#define CPER_SEC_NVIDIA							\
+	GUID_INIT(0x6d5244f2, 0x2712, 0x11ec, 0xbe, 0xa7, 0xcb, 0x3f,	\
+		  0xdb, 0x95, 0xc7, 0x86)
 
 #define CPER_PROC_VALID_TYPE			0x0001
 #define CPER_PROC_VALID_ISA			0x0002
-- 
2.43.0