From 4f90742d4a09a8253861b0d5fd0984e3cd399c9b Mon Sep 17 00:00:00 2001
From: Francesco Pompo <francescopompo2@gmail.com>
Date: Mon, 3 Nov 2025 13:25:39 +0100
Subject: [PATCH 01/14] efistub/x86: Add fallback for SMBIOS record lookup

Some Apple EFI firmwares do not provide the SMBIOS Protocol,
causing efi_get_smbios_record() to fail. This prevents retrieval of
system information such as product name, which is needed by
apple_set_os() to enable the integrated GPU on dual-graphics Intel
MacBooks.

Add a fallback that directly parses the SMBIOS entry point table when
the protocol is unavailable.

Signed-off-by: Francesco Pompo <francescopompo2@gmail.com>
[ardb: cosmetic tweaks]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 drivers/firmware/efi/libstub/x86-stub.c | 101 +++++++++++++++++++++++-
 1 file changed, 100 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c
index 761121a77f9e..dd9e19c31dd7 100644
--- a/drivers/firmware/efi/libstub/x86-stub.c
+++ b/drivers/firmware/efi/libstub/x86-stub.c
@@ -203,6 +203,104 @@ static void retrieve_apple_device_properties(struct boot_params *boot_params)
 	}
 }
 
+struct smbios_entry_point {
+	u8	anchor[4];
+	u8	ep_checksum;
+	u8	ep_length;
+	u8	major_version;
+	u8	minor_version;
+	u16	max_size_entry;
+	u8	ep_rev;
+	u8	reserved[5];
+
+	struct __packed {
+		u8	anchor[5];
+		u8	checksum;
+		u16	st_length;
+		u32	st_address;
+		u16	number_of_entries;
+		u8	bcd_rev;
+	} intm;
+};
+
+static bool verify_ep_checksum(const void *ptr, int length)
+{
+	u8 sum = 0;
+
+	for (int i = 0; i < length; i++)
+		sum += ((u8 *)ptr)[i];
+
+	return sum == 0;
+}
+
+static bool verify_ep_integrity(const struct smbios_entry_point *ep)
+{
+	if (memcmp(ep->anchor, "_SM_", sizeof(ep->anchor)) != 0)
+		return false;
+
+	if (memcmp(ep->intm.anchor, "_DMI_", sizeof(ep->intm.anchor)) != 0)
+		return false;
+
+	if (!verify_ep_checksum(ep, ep->ep_length) ||
+	    !verify_ep_checksum(&ep->intm, sizeof(ep->intm)))
+		return false;
+
+	return true;
+}
+
+static const struct efi_smbios_record *search_record(void *table, u32 length,
+						     u8 type)
+{
+	const u8 *p, *end;
+
+	p = (u8 *)table;
+	end = p + length;
+
+	while (p + sizeof(struct efi_smbios_record) < end) {
+		const struct efi_smbios_record *hdr =
+			(struct efi_smbios_record *)p;
+		const u8 *next;
+
+		if (hdr->type == type)
+			return hdr;
+
+		/* Type 127 = End-of-Table */
+		if (hdr->type == 0x7F)
+			return NULL;
+
+		/* Jumping to the unformed section */
+		next = p + hdr->length;
+
+		/* Unformed section ends with 0000h */
+		while ((next[0] != 0 || next[1] != 0) && next + 1 < end)
+			next++;
+
+		next += 2;
+		p = next;
+	}
+
+	return NULL;
+}
+
+static const struct efi_smbios_record *get_table_record(u8 type)
+{
+	const struct smbios_entry_point *ep;
+
+	/*
+	 * Locate the legacy 32-bit SMBIOS entrypoint in memory, and parse it
+	 * directly. Needed by some Macs that do not implement the EFI protocol.
+	 */
+	ep = get_efi_config_table(SMBIOS_TABLE_GUID);
+	if (!ep)
+		return NULL;
+
+	if (!verify_ep_integrity(ep))
+		return NULL;
+
+	return search_record((void *)(unsigned long)ep->intm.st_address,
+			     ep->intm.st_length, type);
+}
+
 static bool apple_match_product_name(void)
 {
 	static const char type1_product_matches[][15] = {
@@ -218,7 +316,8 @@ static bool apple_match_product_name(void)
 	const struct efi_smbios_type1_record *record;
 	const u8 *product;
 
-	record = (struct efi_smbios_type1_record *)efi_get_smbios_record(1);
+	record = (struct efi_smbios_type1_record *)
+			(efi_get_smbios_record(1) ?: get_table_record(1));
 	if (!record)
 		return false;
 

From 935f94ccb95b81517c73042f44a5d9396bd20dc4 Mon Sep 17 00:00:00 2001
From: Qiang Ma <maqianga@uniontech.com>
Date: Fri, 31 Oct 2025 10:43:28 +0800
Subject: [PATCH 02/14] efi/riscv: Remove the useless failure return message
 print

In the efi_create_mapping() in arch/riscv/kernel/efi.c,
the return value is always 0, and this debug message
is unnecessary. So, remove it.

Signed-off-by: Qiang Ma <maqianga@uniontech.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 drivers/firmware/efi/riscv-runtime.c | 10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/drivers/firmware/efi/riscv-runtime.c b/drivers/firmware/efi/riscv-runtime.c
index fa71cd898120..4a2588358be2 100644
--- a/drivers/firmware/efi/riscv-runtime.c
+++ b/drivers/firmware/efi/riscv-runtime.c
@@ -36,20 +36,12 @@ static bool __init efi_virtmap_init(void)
 	init_new_context(NULL, &efi_mm);
 
 	for_each_efi_memory_desc(md) {
-		phys_addr_t phys = md->phys_addr;
-		int ret;
-
 		if (!(md->attribute & EFI_MEMORY_RUNTIME))
 			continue;
 		if (md->virt_addr == U64_MAX)
 			return false;
 
-		ret = efi_create_mapping(&efi_mm, md);
-		if (ret) {
-			pr_warn("  EFI remap %pa: failed to create mapping (%d)\n",
-				&phys, ret);
-			return false;
-		}
+		efi_create_mapping(&efi_mm, md);
 	}
 
 	if (efi_memattr_apply_permissions(&efi_mm, efi_set_mapping_permissions))

From 793b13541c2f47cc4822e2567ab4113a4d931c56 Mon Sep 17 00:00:00 2001
From: Randy Dunlap <rdunlap@infradead.org>
Date: Mon, 10 Nov 2025 22:02:12 -0800
Subject: [PATCH 03/14] efi: stmm: fix kernel-doc "bad line" warnings

Add a beginning " *" to each line to avoid kernel-doc warnings:

Warning: drivers/firmware/efi/stmm/mm_communication.h:34 bad line:
Warning: drivers/firmware/efi/stmm/mm_communication.h:113 bad line:
Warning: drivers/firmware/efi/stmm/mm_communication.h:130 bad line:

Fixes: c44b6be62e8d ("efi: Add tee-based EFI variable driver")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 drivers/firmware/efi/stmm/mm_communication.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/firmware/efi/stmm/mm_communication.h b/drivers/firmware/efi/stmm/mm_communication.h
index 52a1f32cd1eb..06e7663f96dc 100644
--- a/drivers/firmware/efi/stmm/mm_communication.h
+++ b/drivers/firmware/efi/stmm/mm_communication.h
@@ -32,7 +32,7 @@
 
 /**
  * struct efi_mm_communicate_header - Header used for SMM variable communication
-
+ *
  * @header_guid:  header use for disambiguation of content
  * @message_len:  length of the message. Does not include the size of the
  *                header
@@ -111,7 +111,7 @@ struct efi_mm_communicate_header {
 
 /**
  * struct smm_variable_communicate_header - Used for SMM variable communication
-
+ *
  * @function:     function to call in Smm.
  * @ret_status:   return status
  * @data:         payload
@@ -128,7 +128,7 @@ struct smm_variable_communicate_header {
 /**
  * struct smm_variable_access - Used to communicate with StMM by
  *                              SetVariable and GetVariable.
-
+ *
  * @guid:         vendor GUID
  * @data_size:    size of EFI variable data
  * @name_size:    size of EFI name

From cb46a58d77e5b433e9f4538faaa2a73970157e8d Mon Sep 17 00:00:00 2001
From: Breno Leitao <leitao@debian.org>
Date: Fri, 10 Oct 2025 03:44:04 -0700
Subject: [PATCH 04/14] efi/memattr: Convert efi_memattr_init() return type to
 void

The efi_memattr_init() function's return values (0 and -ENOMEM) are never
checked by callers. Convert the function to return void since the return
status is unused.

Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 drivers/firmware/efi/memattr.c | 7 +++----
 include/linux/efi.h            | 2 +-
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/firmware/efi/memattr.c b/drivers/firmware/efi/memattr.c
index c38b1a335590..e727cc5909cb 100644
--- a/drivers/firmware/efi/memattr.c
+++ b/drivers/firmware/efi/memattr.c
@@ -19,19 +19,19 @@ unsigned long __ro_after_init efi_mem_attr_table = EFI_INVALID_TABLE_ADDR;
  * Reserve the memory associated with the Memory Attributes configuration
  * table, if it exists.
  */
-int __init efi_memattr_init(void)
+void __init efi_memattr_init(void)
 {
 	efi_memory_attributes_table_t *tbl;
 	unsigned long size;
 
 	if (efi_mem_attr_table == EFI_INVALID_TABLE_ADDR)
-		return 0;
+		return;
 
 	tbl = early_memremap(efi_mem_attr_table, sizeof(*tbl));
 	if (!tbl) {
 		pr_err("Failed to map EFI Memory Attributes table @ 0x%lx\n",
 		       efi_mem_attr_table);
-		return -ENOMEM;
+		return;
 	}
 
 	if (tbl->version > 2) {
@@ -61,7 +61,6 @@ int __init efi_memattr_init(void)
 
 unmap:
 	early_memunmap(tbl, sizeof(*tbl));
-	return 0;
 }
 
 /*
diff --git a/include/linux/efi.h b/include/linux/efi.h
index a98cc39e7aaa..0b9eb3d2ff97 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -772,7 +772,7 @@ extern unsigned long efi_mem_attr_table;
  */
 typedef int (*efi_memattr_perm_setter)(struct mm_struct *, efi_memory_desc_t *, bool);
 
-extern int efi_memattr_init(void);
+extern void efi_memattr_init(void);
 extern int efi_memattr_apply_permissions(struct mm_struct *mm,
 					 efi_memattr_perm_setter fn);
 

From d85b56af22f371409cbf667bab26f938e6528d2e Mon Sep 17 00:00:00 2001
From: Thomas Zimmermann <tzimmermann@suse.de>
Date: Wed, 15 Oct 2025 17:56:30 +0200
Subject: [PATCH 05/14] efi: Fix trailing whitespace in header file

Resolve an issue with the coding style.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 include/linux/efi.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/efi.h b/include/linux/efi.h
index 0b9eb3d2ff97..60e994096e20 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -290,7 +290,7 @@ typedef efi_status_t efi_get_variable_t (efi_char16_t *name, efi_guid_t *vendor,
 					 unsigned long *data_size, void *data);
 typedef efi_status_t efi_get_next_variable_t (unsigned long *name_size, efi_char16_t *name,
 					      efi_guid_t *vendor);
-typedef efi_status_t efi_set_variable_t (efi_char16_t *name, efi_guid_t *vendor, 
+typedef efi_status_t efi_set_variable_t (efi_char16_t *name, efi_guid_t *vendor,
 					 u32 attr, unsigned long data_size,
 					 void *data);
 typedef efi_status_t efi_get_next_high_mono_count_t (u32 *count);

From 9d805709d897dc3765d32630178ef8c8b2b624ee Mon Sep 17 00:00:00 2001
From: Thomas Zimmermann <tzimmermann@suse.de>
Date: Wed, 15 Oct 2025 17:56:31 +0200
Subject: [PATCH 06/14] efi/libstub: gop: Find GOP handle instead of GOP data

The device handle of the GOP device is required to retrieve the
correct EDID data. Find the handle instead of the GOP data. Still
return the GOP data in the function arguments, as we already looked
it up.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 drivers/firmware/efi/libstub/gop.c | 27 +++++++++++++++++----------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/drivers/firmware/efi/libstub/gop.c b/drivers/firmware/efi/libstub/gop.c
index 3785fb4986b4..fd32be8dd146 100644
--- a/drivers/firmware/efi/libstub/gop.c
+++ b/drivers/firmware/efi/libstub/gop.c
@@ -402,12 +402,13 @@ setup_pixel_info(struct screen_info *si, u32 pixels_per_scan_line,
 	}
 }
 
-static efi_graphics_output_protocol_t *find_gop(unsigned long num,
-						const efi_handle_t handles[])
+static efi_handle_t find_handle_with_primary_gop(unsigned long num, const efi_handle_t handles[],
+						 efi_graphics_output_protocol_t **found_gop)
 {
 	efi_graphics_output_protocol_t *first_gop;
-	efi_handle_t h;
+	efi_handle_t h, first_gop_handle;
 
+	first_gop_handle = NULL;
 	first_gop = NULL;
 
 	for_each_efi_handle(h, handles, num) {
@@ -442,19 +443,25 @@ static efi_graphics_output_protocol_t *find_gop(unsigned long num,
 		 */
 		status = efi_bs_call(handle_protocol, h,
 				     &EFI_CONSOLE_OUT_DEVICE_GUID, &dummy);
-		if (status == EFI_SUCCESS)
-			return gop;
-
-		if (!first_gop)
+		if (status == EFI_SUCCESS) {
+			if (found_gop)
+				*found_gop = gop;
+			return h;
+		} else if (!first_gop_handle) {
+			first_gop_handle = h;
 			first_gop = gop;
+		}
 	}
 
-	return first_gop;
+	if (found_gop)
+		*found_gop = first_gop;
+	return first_gop_handle;
 }
 
 efi_status_t efi_setup_gop(struct screen_info *si)
 {
 	efi_handle_t *handles __free(efi_pool) = NULL;
+	efi_handle_t handle;
 	efi_graphics_output_protocol_mode_t *mode;
 	efi_graphics_output_mode_info_t *info;
 	efi_graphics_output_protocol_t *gop;
@@ -467,8 +474,8 @@ efi_status_t efi_setup_gop(struct screen_info *si)
 	if (status != EFI_SUCCESS)
 		return status;
 
-	gop = find_gop(num, handles);
-	if (!gop)
+	handle = find_handle_with_primary_gop(num, handles, &gop);
+	if (!handle)
 		return EFI_NOT_FOUND;
 
 	/* Change mode if requested */

From ae42b9c5ddda213feb4e5e57673c4b1f9d2f5541 Mon Sep 17 00:00:00 2001
From: Thomas Zimmermann <tzimmermann@suse.de>
Date: Wed, 15 Oct 2025 17:56:32 +0200
Subject: [PATCH 07/14] efi/libstub: gop: Initialize screen_info in helper
 function

Move initialization of screen_info into a single helper function.
Frees up space in the main setup helper for adding EDID support.
No functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 drivers/firmware/efi/libstub/gop.c | 76 +++++++++++++-----------------
 1 file changed, 33 insertions(+), 43 deletions(-)

diff --git a/drivers/firmware/efi/libstub/gop.c b/drivers/firmware/efi/libstub/gop.c
index fd32be8dd146..02459ef0f18c 100644
--- a/drivers/firmware/efi/libstub/gop.c
+++ b/drivers/firmware/efi/libstub/gop.c
@@ -367,24 +367,31 @@ static void find_bits(u32 mask, u8 *pos, u8 *size)
 	*size = __fls(mask) - *pos + 1;
 }
 
-static void
-setup_pixel_info(struct screen_info *si, u32 pixels_per_scan_line,
-		 efi_pixel_bitmask_t pixel_info, int pixel_format)
+static void setup_screen_info(struct screen_info *si, const efi_graphics_output_protocol_t *gop)
 {
-	if (pixel_format == PIXEL_BIT_MASK) {
-		find_bits(pixel_info.red_mask,
-			  &si->red_pos, &si->red_size);
-		find_bits(pixel_info.green_mask,
-			  &si->green_pos, &si->green_size);
-		find_bits(pixel_info.blue_mask,
-			  &si->blue_pos, &si->blue_size);
-		find_bits(pixel_info.reserved_mask,
-			  &si->rsvd_pos, &si->rsvd_size);
-		si->lfb_depth = si->red_size + si->green_size +
-			si->blue_size + si->rsvd_size;
-		si->lfb_linelength = (pixels_per_scan_line * si->lfb_depth) / 8;
+	const efi_graphics_output_protocol_mode_t *mode = efi_table_attr(gop, mode);
+	const efi_graphics_output_mode_info_t *info = efi_table_attr(mode, info);
+
+	si->orig_video_isVGA = VIDEO_TYPE_EFI;
+
+	si->lfb_width  = info->horizontal_resolution;
+	si->lfb_height = info->vertical_resolution;
+
+	efi_set_u64_split(efi_table_attr(mode, frame_buffer_base),
+			  &si->lfb_base, &si->ext_lfb_base);
+	if (si->ext_lfb_base)
+		si->capabilities |= VIDEO_CAPABILITY_64BIT_BASE;
+	si->pages = 1;
+
+	if (info->pixel_format == PIXEL_BIT_MASK) {
+		find_bits(info->pixel_information.red_mask, &si->red_pos, &si->red_size);
+		find_bits(info->pixel_information.green_mask, &si->green_pos, &si->green_size);
+		find_bits(info->pixel_information.blue_mask, &si->blue_pos, &si->blue_size);
+		find_bits(info->pixel_information.reserved_mask, &si->rsvd_pos, &si->rsvd_size);
+		si->lfb_depth = si->red_size + si->green_size + si->blue_size + si->rsvd_size;
+		si->lfb_linelength = (info->pixels_per_scan_line * si->lfb_depth) / 8;
 	} else {
-		if (pixel_format == PIXEL_RGB_RESERVED_8BIT_PER_COLOR) {
+		if (info->pixel_format == PIXEL_RGB_RESERVED_8BIT_PER_COLOR) {
 			si->red_pos   = 0;
 			si->blue_pos  = 16;
 		} else /* PIXEL_BGR_RESERVED_8BIT_PER_COLOR */ {
@@ -394,12 +401,16 @@ setup_pixel_info(struct screen_info *si, u32 pixels_per_scan_line,
 
 		si->green_pos = 8;
 		si->rsvd_pos  = 24;
-		si->red_size = si->green_size =
-			si->blue_size = si->rsvd_size = 8;
-
+		si->red_size = 8;
+		si->green_size = 8;
+		si->blue_size = 8;
+		si->rsvd_size = 8;
 		si->lfb_depth = 32;
-		si->lfb_linelength = pixels_per_scan_line * 4;
+		si->lfb_linelength = info->pixels_per_scan_line * 4;
 	}
+
+	si->lfb_size = si->lfb_linelength * si->lfb_height;
+	si->capabilities |= VIDEO_CAPABILITY_SKIP_QUIRKS;
 }
 
 static efi_handle_t find_handle_with_primary_gop(unsigned long num, const efi_handle_t handles[],
@@ -462,8 +473,6 @@ efi_status_t efi_setup_gop(struct screen_info *si)
 {
 	efi_handle_t *handles __free(efi_pool) = NULL;
 	efi_handle_t handle;
-	efi_graphics_output_protocol_mode_t *mode;
-	efi_graphics_output_mode_info_t *info;
 	efi_graphics_output_protocol_t *gop;
 	efi_status_t status;
 	unsigned long num;
@@ -482,27 +491,8 @@ efi_status_t efi_setup_gop(struct screen_info *si)
 	set_mode(gop);
 
 	/* EFI framebuffer */
-	mode = efi_table_attr(gop, mode);
-	info = efi_table_attr(mode, info);
-
-	si->orig_video_isVGA = VIDEO_TYPE_EFI;
-
-	si->lfb_width  = info->horizontal_resolution;
-	si->lfb_height = info->vertical_resolution;
-
-	efi_set_u64_split(efi_table_attr(mode, frame_buffer_base),
-			  &si->lfb_base, &si->ext_lfb_base);
-	if (si->ext_lfb_base)
-		si->capabilities |= VIDEO_CAPABILITY_64BIT_BASE;
-
-	si->pages = 1;
-
-	setup_pixel_info(si, info->pixels_per_scan_line,
-			     info->pixel_information, info->pixel_format);
-
-	si->lfb_size = si->lfb_linelength * si->lfb_height;
-
-	si->capabilities |= VIDEO_CAPABILITY_SKIP_QUIRKS;
+	if (si)
+		setup_screen_info(si, gop);
 
 	return EFI_SUCCESS;
 }

From 17029cdd8f9d0182a6499e0b7bfc6391e8463091 Mon Sep 17 00:00:00 2001
From: Thomas Zimmermann <tzimmermann@suse.de>
Date: Wed, 15 Oct 2025 17:56:33 +0200
Subject: [PATCH 08/14] efi/libstub: gop: Add support for reading EDID

Add support for EFI_EDID_DISCOVERED_PROTOCOL and EFI_EDID_ACTIVE_PROTOCOL
as defined in UEFI 2.8, sec 12.9. Define GUIDs and data structures in the
rsp header files.

In the GOP setup function, read the EDID of the primary GOP device. First
try EFI_EDID_ACTIVE_PROTOCOL, which supports user-specified EDID data. Or
else try EFI_EDID_DISCOVERED_PROTOCOL, which returns the display device's
native EDID. If no EDID could be retrieved, clear the storage.

Rename efi_setup_gop() to efi_setup_graphics() to reflect the changes
Let callers pass an optional instance of struct edid_data, if they are
interested.

While screen_info and edid_info come from the same device handle, they
should be considered indendent data. The former refers to the graphics
mode, the latter refers to the display device. GOP devices might not
provide both.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 drivers/firmware/efi/libstub/efi-stub.c |  2 +-
 drivers/firmware/efi/libstub/efistub.h  | 31 ++++++++++++++++++++-
 drivers/firmware/efi/libstub/gop.c      | 36 ++++++++++++++++++++++++-
 drivers/firmware/efi/libstub/x86-stub.c |  2 +-
 include/linux/efi.h                     |  2 ++
 5 files changed, 69 insertions(+), 4 deletions(-)

diff --git a/drivers/firmware/efi/libstub/efi-stub.c b/drivers/firmware/efi/libstub/efi-stub.c
index 874f63b4a383..9cb814c5ba1b 100644
--- a/drivers/firmware/efi/libstub/efi-stub.c
+++ b/drivers/firmware/efi/libstub/efi-stub.c
@@ -56,7 +56,7 @@ static struct screen_info *setup_graphics(void)
 {
 	struct screen_info *si, tmp = {};
 
-	if (efi_setup_gop(&tmp) != EFI_SUCCESS)
+	if (efi_setup_graphics(&tmp, NULL) != EFI_SUCCESS)
 		return NULL;
 
 	si = alloc_screen_info();
diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index f5ba032863a9..b2fb0c3fa721 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -34,6 +34,9 @@
 #define EFI_ALLOC_LIMIT		ULONG_MAX
 #endif
 
+struct edid_info;
+struct screen_info;
+
 extern bool efi_no5lvl;
 extern bool efi_nochunk;
 extern bool efi_nokaslr;
@@ -578,6 +581,32 @@ union efi_graphics_output_protocol {
 	} mixed_mode;
 };
 
+typedef union efi_edid_discovered_protocol efi_edid_discovered_protocol_t;
+
+union efi_edid_discovered_protocol {
+	struct {
+		u32 size_of_edid;
+		u8 *edid;
+	};
+	struct {
+		u32 size_of_edid;
+		u32 edid;
+	} mixed_mode;
+};
+
+typedef union efi_edid_active_protocol efi_edid_active_protocol_t;
+
+union efi_edid_active_protocol {
+	struct {
+		u32 size_of_edid;
+		u8 *edid;
+	};
+	struct {
+		u32 size_of_edid;
+		u32 edid;
+	} mixed_mode;
+};
+
 typedef union {
 	struct {
 		u32			revision;
@@ -1085,7 +1114,7 @@ efi_status_t efi_parse_options(char const *cmdline);
 
 void efi_parse_option_graphics(char *option);
 
-efi_status_t efi_setup_gop(struct screen_info *si);
+efi_status_t efi_setup_graphics(struct screen_info *si, struct edid_info *edid);
 
 efi_status_t handle_cmdline_files(efi_loaded_image_t *image,
 				  const efi_char16_t *optstr,
diff --git a/drivers/firmware/efi/libstub/gop.c b/drivers/firmware/efi/libstub/gop.c
index 02459ef0f18c..72d74436a7a4 100644
--- a/drivers/firmware/efi/libstub/gop.c
+++ b/drivers/firmware/efi/libstub/gop.c
@@ -12,6 +12,7 @@
 #include <linux/string.h>
 #include <asm/efi.h>
 #include <asm/setup.h>
+#include <video/edid.h>
 
 #include "efistub.h"
 
@@ -413,6 +414,14 @@ static void setup_screen_info(struct screen_info *si, const efi_graphics_output_
 	si->capabilities |= VIDEO_CAPABILITY_SKIP_QUIRKS;
 }
 
+static void setup_edid_info(struct edid_info *edid, u32 gop_size_of_edid, u8 *gop_edid)
+{
+	if (!gop_edid || gop_size_of_edid < 128)
+		memset(edid->dummy, 0, sizeof(edid->dummy));
+	else
+		memcpy(edid->dummy, gop_edid, min(gop_size_of_edid, sizeof(edid->dummy)));
+}
+
 static efi_handle_t find_handle_with_primary_gop(unsigned long num, const efi_handle_t handles[],
 						 efi_graphics_output_protocol_t **found_gop)
 {
@@ -469,7 +478,7 @@ static efi_handle_t find_handle_with_primary_gop(unsigned long num, const efi_ha
 	return first_gop_handle;
 }
 
-efi_status_t efi_setup_gop(struct screen_info *si)
+efi_status_t efi_setup_graphics(struct screen_info *si, struct edid_info *edid)
 {
 	efi_handle_t *handles __free(efi_pool) = NULL;
 	efi_handle_t handle;
@@ -494,5 +503,30 @@ efi_status_t efi_setup_gop(struct screen_info *si)
 	if (si)
 		setup_screen_info(si, gop);
 
+	/* Display EDID for primary GOP */
+	if (edid) {
+		efi_edid_discovered_protocol_t *discovered_edid;
+		efi_edid_active_protocol_t *active_edid;
+		u32 gop_size_of_edid = 0;
+		u8 *gop_edid = NULL;
+
+		status = efi_bs_call(handle_protocol, handle, &EFI_EDID_ACTIVE_PROTOCOL_GUID,
+				     (void **)&active_edid);
+		if (status == EFI_SUCCESS) {
+			gop_size_of_edid = active_edid->size_of_edid;
+			gop_edid = active_edid->edid;
+		} else {
+			status = efi_bs_call(handle_protocol, handle,
+					     &EFI_EDID_DISCOVERED_PROTOCOL_GUID,
+					     (void **)&discovered_edid);
+			if (status == EFI_SUCCESS) {
+				gop_size_of_edid = discovered_edid->size_of_edid;
+				gop_edid = discovered_edid->edid;
+			}
+		}
+
+		setup_edid_info(edid, gop_size_of_edid, gop_edid);
+	}
+
 	return EFI_SUCCESS;
 }
diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c
index dd9e19c31dd7..6e51cca72684 100644
--- a/drivers/firmware/efi/libstub/x86-stub.c
+++ b/drivers/firmware/efi/libstub/x86-stub.c
@@ -488,7 +488,7 @@ static void setup_graphics(struct boot_params *boot_params)
 {
 	struct screen_info *si = memset(&boot_params->screen_info, 0, sizeof(*si));
 
-	efi_setup_gop(si);
+	efi_setup_graphics(si, NULL);
 }
 
 static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status)
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 60e994096e20..a01f3fe20dab 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -373,6 +373,8 @@ void efi_native_runtime_setup(void);
 #define EFI_DEVICE_PATH_TO_TEXT_PROTOCOL_GUID	EFI_GUID(0x8b843e20, 0x8132, 0x4852,  0x90, 0xcc, 0x55, 0x1a, 0x4e, 0x4a, 0x7f, 0x1c)
 #define EFI_DEVICE_PATH_FROM_TEXT_PROTOCOL_GUID	EFI_GUID(0x05c99a21, 0xc70f, 0x4ad2,  0x8a, 0x5f, 0x35, 0xdf, 0x33, 0x43, 0xf5, 0x1e)
 #define EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID	EFI_GUID(0x9042a9de, 0x23dc, 0x4a38,  0x96, 0xfb, 0x7a, 0xde, 0xd0, 0x80, 0x51, 0x6a)
+#define EFI_EDID_DISCOVERED_PROTOCOL_GUID	EFI_GUID(0x1c0c34f6, 0xd380, 0x41fa,  0xa0, 0x49, 0x8a, 0xd0, 0x6c, 0x1a, 0x66, 0xaa)
+#define EFI_EDID_ACTIVE_PROTOCOL_GUID		EFI_GUID(0xbd8c1056, 0x9f36, 0x44ec,  0x92, 0xa8, 0xa6, 0x33, 0x7f, 0x81, 0x79, 0x86)
 #define EFI_PCI_IO_PROTOCOL_GUID		EFI_GUID(0x4cf5b200, 0x68b8, 0x4ca5,  0x9e, 0xec, 0xb2, 0x3e, 0x3f, 0x50, 0x02, 0x9a)
 #define EFI_FILE_INFO_ID			EFI_GUID(0x09576e92, 0x6d3f, 0x11d2,  0x8e, 0x39, 0x00, 0xa0, 0xc9, 0x69, 0x72, 0x3b)
 #define EFI_SYSTEM_RESOURCE_TABLE_GUID		EFI_GUID(0xb122a263, 0x3661, 0x4f68,  0x99, 0x29, 0x78, 0xf8, 0xb0, 0xd6, 0x21, 0x80)

From e41ef37ddfe763b829b5b44662ce29e26549b42c Mon Sep 17 00:00:00 2001
From: Thomas Zimmermann <tzimmermann@suse.de>
Date: Wed, 15 Oct 2025 17:56:34 +0200
Subject: [PATCH 09/14] efi/libstub: x86: Store EDID in boot_params

Retrieve the GOP device's EDID information in the kernel's boot
parameters. Makes the data avaialble to kernel graphics code and
drives, such as efidrm.

With efidrm, the EDID is now also available to user-space compositors
via standard DRM interfaces.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 drivers/firmware/efi/libstub/x86-stub.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c
index 6e51cca72684..cef32e2c82d8 100644
--- a/drivers/firmware/efi/libstub/x86-stub.c
+++ b/drivers/firmware/efi/libstub/x86-stub.c
@@ -487,8 +487,9 @@ static void setup_quirks(struct boot_params *boot_params)
 static void setup_graphics(struct boot_params *boot_params)
 {
 	struct screen_info *si = memset(&boot_params->screen_info, 0, sizeof(*si));
+	struct edid_info *edid = memset(&boot_params->edid_info, 0, sizeof(*edid));
 
-	efi_setup_graphics(si, NULL);
+	efi_setup_graphics(si, edid);
 }
 
 static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status)

From 05954511b73e748d0370549ad9dd9cd95297d97a Mon Sep 17 00:00:00 2001
From: Jason Tian <jason@os.amperecomputing.com>
Date: Thu, 14 Aug 2025 09:52:52 -0700
Subject: [PATCH 10/14] RAS: Report all ARM processor CPER information to
 userspace

The ARM processor CPER record was added in UEFI v2.6 and remained
unchanged up to v2.10.

Yet, the original arm_event trace code added by

  e9279e83ad1f ("trace, ras: add ARM processor error trace event")

is incomplete, as it only traces some fields of UAPI 2.6 table N.16, not
exporting any information from tables N.17 to N.29 of the record.

This is not enough for the user to be able to figure out what has
exactly happened or to take appropriate action.

According to the UEFI v2.9 specification chapter N2.4.4, the ARM
processor error section includes:

- several (ERR_INFO_NUM) ARM processor error information structures
  (Tables N.17 to N.20);
- several (CONTEXT_INFO_NUM) ARM processor context information
  structures (Tables N.21 to N.29);
- several vendor specific error information structures. The
  size is given by Section Length minus the size of the other
  fields.

In addition, it also exports two fields that are parsed by the GHES
driver when firmware reports it, e.g.:

- error severity
- CPU logical index

Report all of these information to userspace via a the ARM tracepoint so
that userspace can properly record the error and take decisions related
to CPU core isolation according to error severity and other info.

The updated ARM trace event now contains the following fields:

======================================  =============================
UEFI field on table N.16                ARM Processor trace fields
======================================  =============================
Validation                              handled when filling data for
                                        affinity MPIDR and running
                                        state.
ERR_INFO_NUM                            pei_len
CONTEXT_INFO_NUM                        ctx_len
Section Length                          indirectly reported by
                                        pei_len, ctx_len and oem_len
Error affinity level                    affinity
MPIDR_EL1                               mpidr
MIDR_EL1                                midr
Running State                           running_state
PSCI State                              psci_state
Processor Error Information Structure   pei_err - count at pei_len
Processor Context                       ctx_err- count at ctx_len
Vendor Specific Error Info              oem - count at oem_len
======================================  =============================

It should be noted that decoding of tables N.17 to N.29, if needed, will
be handled in userspace. That gives more flexibility, as there won't be
any need to flood the kernel with micro-architecture specific error
decoding.

Also, decoding the other fields require a complex logic, and should be
done for each of the several values inside the record field.  So, let
userspace daemons like rasdaemon decode them, parsing such tables and
having vendor-specific micro-architecture-specific decoders.

 [mchehab: modified description, solved merge conflicts and fixed coding style]

Signed-off-by: Jason Tian <jason@os.amperecomputing.com>
Co-developed-by: Shengwei Luo <luoshengwei@huawei.com>
Signed-off-by: Shengwei Luo <luoshengwei@huawei.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Daniel Ferguson <danielf@os.amperecomputing.com> # rebased
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Tested-by: Shiju Jose <shiju.jose@huawei.com>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Fixes: e9279e83ad1f ("trace, ras: add ARM processor error trace event")
Link: https://uefi.org/specs/UEFI/2.10/Apx_N_Common_Platform_Error_Record.html#arm-processor-error-section
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 drivers/acpi/apei/ghes.c | 11 ++++-----
 drivers/ras/ras.c        | 40 ++++++++++++++++++++++++++++++--
 include/linux/ras.h      | 16 ++++++++++---
 include/ras/ras_event.h  | 49 ++++++++++++++++++++++++++++++++++++----
 4 files changed, 99 insertions(+), 17 deletions(-)

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 97ee19f2cae0..7d2466b51504 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -552,7 +552,7 @@ static bool ghes_handle_memory_failure(struct acpi_hest_generic_data *gdata,
 }
 
 static bool ghes_handle_arm_hw_error(struct acpi_hest_generic_data *gdata,
-				       int sev, bool sync)
+				     int sev, bool sync)
 {
 	struct cper_sec_proc_arm *err = acpi_hest_get_payload(gdata);
 	int flags = sync ? MF_ACTION_REQUIRED : 0;
@@ -560,9 +560,8 @@ static bool ghes_handle_arm_hw_error(struct acpi_hest_generic_data *gdata,
 	int sec_sev, i;
 	char *p;
 
-	log_arm_hw_error(err);
-
 	sec_sev = ghes_severity(gdata->error_severity);
+	log_arm_hw_error(err, sec_sev);
 	if (sev != GHES_SEV_RECOVERABLE || sec_sev != GHES_SEV_RECOVERABLE)
 		return false;
 
@@ -895,11 +894,9 @@ static void ghes_do_proc(struct ghes *ghes,
 
 			arch_apei_report_mem_error(sev, mem_err);
 			queued = ghes_handle_memory_failure(gdata, sev, sync);
-		}
-		else if (guid_equal(sec_type, &CPER_SEC_PCIE)) {
+		} else if (guid_equal(sec_type, &CPER_SEC_PCIE)) {
 			ghes_handle_aer(gdata);
-		}
-		else if (guid_equal(sec_type, &CPER_SEC_PROC_ARM)) {
+		} else if (guid_equal(sec_type, &CPER_SEC_PROC_ARM)) {
 			queued = ghes_handle_arm_hw_error(gdata, sev, sync);
 		} else if (guid_equal(sec_type, &CPER_SEC_CXL_PROT_ERR)) {
 			struct cxl_cper_sec_prot_err *prot_err = acpi_hest_get_payload(gdata);
diff --git a/drivers/ras/ras.c b/drivers/ras/ras.c
index ac0e132ccc3e..2a5b5a9fdcb3 100644
--- a/drivers/ras/ras.c
+++ b/drivers/ras/ras.c
@@ -53,9 +53,45 @@ void log_non_standard_event(const guid_t *sec_type, const guid_t *fru_id,
 }
 EXPORT_SYMBOL_GPL(log_non_standard_event);
 
-void log_arm_hw_error(struct cper_sec_proc_arm *err)
+void log_arm_hw_error(struct cper_sec_proc_arm *err, const u8 sev)
 {
-	trace_arm_event(err);
+	struct cper_arm_err_info *err_info;
+	struct cper_arm_ctx_info *ctx_info;
+	u8 *ven_err_data;
+	u32 ctx_len = 0;
+	int n, sz, cpu;
+	s32 vsei_len;
+	u32 pei_len;
+	u8 *pei_err, *ctx_err;
+
+	pei_len = sizeof(struct cper_arm_err_info) * err->err_info_num;
+	pei_err = (u8 *)(err + 1);
+
+	err_info = (struct cper_arm_err_info *)(err + 1);
+	ctx_info = (struct cper_arm_ctx_info *)(err_info + err->err_info_num);
+	ctx_err = (u8 *)ctx_info;
+
+	for (n = 0; n < err->context_info_num; n++) {
+		sz = sizeof(struct cper_arm_ctx_info) + ctx_info->size;
+		ctx_info = (struct cper_arm_ctx_info *)((long)ctx_info + sz);
+		ctx_len += sz;
+	}
+
+	vsei_len = err->section_length - (sizeof(struct cper_sec_proc_arm) + pei_len + ctx_len);
+	if (vsei_len < 0) {
+		pr_warn(FW_BUG "section length: %d\n", err->section_length);
+		pr_warn(FW_BUG "section length is too small\n");
+		pr_warn(FW_BUG "firmware-generated error record is incorrect\n");
+		vsei_len = 0;
+	}
+	ven_err_data = (u8 *)ctx_info;
+
+	cpu = GET_LOGICAL_INDEX(err->mpidr);
+	if (cpu < 0)
+		cpu = -1;
+
+	trace_arm_event(err, pei_err, pei_len, ctx_err, ctx_len,
+			ven_err_data, (u32)vsei_len, sev, cpu);
 }
 
 static int __init ras_init(void)
diff --git a/include/linux/ras.h b/include/linux/ras.h
index a64182bc72ad..468941bfe855 100644
--- a/include/linux/ras.h
+++ b/include/linux/ras.h
@@ -24,8 +24,7 @@ int __init parse_cec_param(char *str);
 void log_non_standard_event(const guid_t *sec_type,
 			    const guid_t *fru_id, const char *fru_text,
 			    const u8 sev, const u8 *err, const u32 len);
-void log_arm_hw_error(struct cper_sec_proc_arm *err);
-
+void log_arm_hw_error(struct cper_sec_proc_arm *err, const u8 sev);
 #else
 static inline void
 log_non_standard_event(const guid_t *sec_type,
@@ -33,7 +32,7 @@ log_non_standard_event(const guid_t *sec_type,
 		       const u8 sev, const u8 *err, const u32 len)
 { return; }
 static inline void
-log_arm_hw_error(struct cper_sec_proc_arm *err) { return; }
+log_arm_hw_error(struct cper_sec_proc_arm *err, const u8 sev) { return; }
 #endif
 
 struct atl_err {
@@ -53,4 +52,15 @@ static inline unsigned long
 amd_convert_umc_mca_addr_to_sys_addr(struct atl_err *err) { return -EINVAL; }
 #endif /* CONFIG_AMD_ATL */
 
+#if defined(CONFIG_ARM) || defined(CONFIG_ARM64)
+#include <asm/smp_plat.h>
+/*
+ * Include ARM-specific SMP header which provides a function mapping mpidr to
+ * CPU logical index.
+ */
+#define GET_LOGICAL_INDEX(mpidr) get_logical_index(mpidr & MPIDR_HWID_BITMASK)
+#else
+#define GET_LOGICAL_INDEX(mpidr) -EINVAL
+#endif /* CONFIG_ARM || CONFIG_ARM64 */
+
 #endif /* __RAS_H__ */
diff --git a/include/ras/ras_event.h b/include/ras/ras_event.h
index c8cd0f00c845..c9f0b1018bcc 100644
--- a/include/ras/ras_event.h
+++ b/include/ras/ras_event.h
@@ -168,11 +168,25 @@ TRACE_EVENT(mc_event,
  * This event is generated when hardware detects an ARM processor error
  * has occurred. UEFI 2.6 spec section N.2.4.4.
  */
+#define APEIL "ARM Processor Err Info data len"
+#define APEID "ARM Processor Err Info raw data"
+#define APECIL "ARM Processor Err Context Info data len"
+#define APECID "ARM Processor Err Context Info raw data"
+#define VSEIL "Vendor Specific Err Info data len"
+#define VSEID "Vendor Specific Err Info raw data"
 TRACE_EVENT(arm_event,
 
-	TP_PROTO(const struct cper_sec_proc_arm *proc),
+	TP_PROTO(const struct cper_sec_proc_arm *proc,
+		 const u8 *pei_err,
+		 const u32 pei_len,
+		 const u8 *ctx_err,
+		 const u32 ctx_len,
+		 const u8 *oem,
+		 const u32 oem_len,
+		 u8 sev,
+		 int cpu),
 
-	TP_ARGS(proc),
+	TP_ARGS(proc, pei_err, pei_len, ctx_err, ctx_len, oem, oem_len, sev, cpu),
 
 	TP_STRUCT__entry(
 		__field(u64, mpidr)
@@ -180,6 +194,14 @@ TRACE_EVENT(arm_event,
 		__field(u32, running_state)
 		__field(u32, psci_state)
 		__field(u8, affinity)
+		__field(u32, pei_len)
+		__dynamic_array(u8, pei_buf, pei_len)
+		__field(u32, ctx_len)
+		__dynamic_array(u8, ctx_buf, ctx_len)
+		__field(u32, oem_len)
+		__dynamic_array(u8, oem_buf, oem_len)
+		__field(u8, sev)
+		__field(int, cpu)
 	),
 
 	TP_fast_assign(
@@ -199,12 +221,29 @@ TRACE_EVENT(arm_event,
 			__entry->running_state = ~0;
 			__entry->psci_state = ~0;
 		}
+		__entry->pei_len = pei_len;
+		memcpy(__get_dynamic_array(pei_buf), pei_err, pei_len);
+		__entry->ctx_len = ctx_len;
+		memcpy(__get_dynamic_array(ctx_buf), ctx_err, ctx_len);
+		__entry->oem_len = oem_len;
+		memcpy(__get_dynamic_array(oem_buf), oem, oem_len);
+		__entry->sev = sev;
+		__entry->cpu = cpu;
 	),
 
-	TP_printk("affinity level: %d; MPIDR: %016llx; MIDR: %016llx; "
-		  "running state: %d; PSCI state: %d",
+	TP_printk("cpu: %d; error: %d; affinity level: %d; MPIDR: %016llx; MIDR: %016llx; "
+		  "running state: %d; PSCI state: %d; "
+		  "%s: %d; %s: %s; %s: %d; %s: %s; %s: %d; %s: %s",
+		  __entry->cpu,
+		  __entry->sev,
 		  __entry->affinity, __entry->mpidr, __entry->midr,
-		  __entry->running_state, __entry->psci_state)
+		  __entry->running_state, __entry->psci_state,
+		  APEIL, __entry->pei_len, APEID,
+		  __print_hex(__get_dynamic_array(pei_buf), __entry->pei_len),
+		  APECIL, __entry->ctx_len, APECID,
+		  __print_hex(__get_dynamic_array(ctx_buf), __entry->ctx_len),
+		  VSEIL, __entry->oem_len, VSEID,
+		  __print_hex(__get_dynamic_array(oem_buf), __entry->oem_len))
 );
 
 /*

From 8ad2c72e21efb3dc76c5b14089fa7984cdd87898 Mon Sep 17 00:00:00 2001
From: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Date: Thu, 14 Aug 2025 09:52:53 -0700
Subject: [PATCH 11/14] efi/cper: Adjust infopfx size to accept an extra space
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Compiling with W=1 with werror enabled produces an error:

drivers/firmware/efi/cper-arm.c: In function ‘cper_print_proc_arm’:
drivers/firmware/efi/cper-arm.c:298:64: error: ‘snprintf’ output may be truncated before the last format character [-Werror=format-truncation=]
  298 |                         snprintf(infopfx, sizeof(infopfx), "%s ", newpfx);
      |                                                                ^
drivers/firmware/efi/cper-arm.c:298:25: note: ‘snprintf’ output between 2 and 65 bytes into a destination of size 64
  298 |                         snprintf(infopfx, sizeof(infopfx), "%s ", newpfx);
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

As the logic there adds an space at the end of infopx buffer.
Add an extra space to avoid such warning.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 drivers/firmware/efi/cper-arm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/firmware/efi/cper-arm.c b/drivers/firmware/efi/cper-arm.c
index f0a63d09d3c4..6ff781e47147 100644
--- a/drivers/firmware/efi/cper-arm.c
+++ b/drivers/firmware/efi/cper-arm.c
@@ -240,7 +240,7 @@ void cper_print_proc_arm(const char *pfx,
 	int i, len, max_ctx_type;
 	struct cper_arm_err_info *err_info;
 	struct cper_arm_ctx_info *ctx_info;
-	char newpfx[64], infopfx[64];
+	char newpfx[64], infopfx[ARRAY_SIZE(newpfx) + 1];
 
 	printk("%sMIDR: 0x%016llx\n", pfx, proc->midr);
 

From a976d790f49499ccaa0f991788ad8ebf92e7fd5c Mon Sep 17 00:00:00 2001
From: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Date: Thu, 14 Aug 2025 09:52:54 -0700
Subject: [PATCH 12/14] efi/cper: Add a new helper function to print bitmasks

Add a helper function to print a string with names associated
to each bit field.

A typical example is:

	const char * const bits[] = {
		"bit 3 name",
		"bit 4 name",
		"bit 5 name",
	};
	char str[120];
        unsigned int bitmask = BIT(3) | BIT(5);

	#define MASK  GENMASK(5,3)

	cper_bits_to_str(str, sizeof(str), FIELD_GET(MASK, bitmask),
			 bits, ARRAY_SIZE(bits));

The above code fills string "str" with "bit 3 name|bit 5 name".

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 drivers/firmware/efi/cper.c | 60 +++++++++++++++++++++++++++++++++++++
 include/linux/cper.h        |  2 ++
 2 files changed, 62 insertions(+)

diff --git a/drivers/firmware/efi/cper.c b/drivers/firmware/efi/cper.c
index 928409199a1a..79ba688a64f8 100644
--- a/drivers/firmware/efi/cper.c
+++ b/drivers/firmware/efi/cper.c
@@ -12,6 +12,7 @@
  * Specification version 2.4.
  */
 
+#include <linux/bitmap.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/time.h>
@@ -106,6 +107,65 @@ void cper_print_bits(const char *pfx, unsigned int bits,
 		printk("%s\n", buf);
 }
 
+/**
+ * cper_bits_to_str - return a string for set bits
+ * @buf: buffer to store the output string
+ * @buf_size: size of the output string buffer
+ * @bits: bit mask
+ * @strs: string array, indexed by bit position
+ * @strs_size: size of the string array: @strs
+ *
+ * Add to @buf the bitmask in hexadecimal. Then, for each set bit in @bits,
+ * add the corresponding string describing the bit in @strs to @buf.
+ *
+ * A typical example is::
+ *
+ *	const char * const bits[] = {
+ *		"bit 3 name",
+ *		"bit 4 name",
+ *		"bit 5 name",
+ *	};
+ *	char str[120];
+ *	unsigned int bitmask = BIT(3) | BIT(5);
+ *	#define MASK GENMASK(5,3)
+ *
+ *	cper_bits_to_str(str, sizeof(str), FIELD_GET(MASK, bitmask),
+ *			 bits, ARRAY_SIZE(bits));
+ *
+ * The above code fills the string ``str`` with ``bit 3 name|bit 5 name``.
+ *
+ * Return: number of bytes stored or an error code if lower than zero.
+ */
+int cper_bits_to_str(char *buf, int buf_size, unsigned long bits,
+		     const char * const strs[], unsigned int strs_size)
+{
+	int len = buf_size;
+	char *str = buf;
+	int i, size;
+
+	*buf = '\0';
+
+	for_each_set_bit(i, &bits, strs_size) {
+		if (!(bits & BIT_ULL(i)))
+			continue;
+
+		if (*buf && len > 0) {
+			*str = '|';
+			len--;
+			str++;
+		}
+
+		size = strscpy(str, strs[i], len);
+		if (size < 0)
+			return size;
+
+		len -= size;
+		str += size;
+	}
+	return len - buf_size;
+}
+EXPORT_SYMBOL_GPL(cper_bits_to_str);
+
 static const char * const proc_type_strs[] = {
 	"IA32/X64",
 	"IA64",
diff --git a/include/linux/cper.h b/include/linux/cper.h
index 0ed60a91eca9..58f40477c824 100644
--- a/include/linux/cper.h
+++ b/include/linux/cper.h
@@ -588,6 +588,8 @@ const char *cper_mem_err_type_str(unsigned int);
 const char *cper_mem_err_status_str(u64 status);
 void cper_print_bits(const char *prefix, unsigned int bits,
 		     const char * const strs[], unsigned int strs_size);
+int cper_bits_to_str(char *buf, int buf_size, unsigned long bits,
+		     const char * const strs[], unsigned int strs_size);
 void cper_mem_err_pack(const struct cper_sec_mem_err *,
 		       struct cper_mem_err_compact *);
 const char *cper_mem_err_unpack(struct trace_seq *,

From 96b010536ee020e716d28d9b359a4bcd18800aeb Mon Sep 17 00:00:00 2001
From: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Date: Thu, 14 Aug 2025 09:52:55 -0700
Subject: [PATCH 13/14] efi/cper: align ARM CPER type with UEFI 2.9A/2.10 specs

Up to UEFI spec 2.9, the type byte of CPER struct for ARM processor
was defined simply as:

Type at byte offset 4:

	- Cache error
	- TLB Error
	- Bus Error
	- Micro-architectural Error
	All other values are reserved

Yet, there was no information about how this would be encoded.

Spec 2.9A errata corrected it by defining:

	- Bit 1 - Cache Error
	- Bit 2 - TLB Error
	- Bit 3 - Bus Error
	- Bit 4 - Micro-architectural Error
	All other values are reserved

That actually aligns with the values already defined on older
versions at N.2.4.1. Generic Processor Error Section.

Spec 2.10 also preserve the same encoding as 2.9A.

Adjust CPER and GHES handling code for both generic and ARM
processors to properly handle UEFI 2.9A and 2.10 encoding.

Link: https://uefi.org/specs/UEFI/2.10/Apx_N_Common_Platform_Error_Record.html#arm-processor-error-information
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 drivers/acpi/apei/ghes.c        | 16 +++++++----
 drivers/firmware/efi/cper-arm.c | 50 ++++++++++++++++-----------------
 include/linux/cper.h            | 10 +++----
 3 files changed, 39 insertions(+), 37 deletions(-)

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 7d2466b51504..56107aa00274 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -22,6 +22,7 @@
 #include <linux/moduleparam.h>
 #include <linux/init.h>
 #include <linux/acpi.h>
+#include <linux/bitfield.h>
 #include <linux/io.h>
 #include <linux/interrupt.h>
 #include <linux/timer.h>
@@ -556,6 +557,7 @@ static bool ghes_handle_arm_hw_error(struct acpi_hest_generic_data *gdata,
 {
 	struct cper_sec_proc_arm *err = acpi_hest_get_payload(gdata);
 	int flags = sync ? MF_ACTION_REQUIRED : 0;
+	char error_type[120];
 	bool queued = false;
 	int sec_sev, i;
 	char *p;
@@ -568,9 +570,8 @@ static bool ghes_handle_arm_hw_error(struct acpi_hest_generic_data *gdata,
 	p = (char *)(err + 1);
 	for (i = 0; i < err->err_info_num; i++) {
 		struct cper_arm_err_info *err_info = (struct cper_arm_err_info *)p;
-		bool is_cache = (err_info->type == CPER_ARM_CACHE_ERROR);
+		bool is_cache = err_info->type & CPER_ARM_CACHE_ERROR;
 		bool has_pa = (err_info->validation_bits & CPER_ARM_INFO_VALID_PHYSICAL_ADDR);
-		const char *error_type = "unknown error";
 
 		/*
 		 * The field (err_info->error_info & BIT(26)) is fixed to set to
@@ -584,12 +585,15 @@ static bool ghes_handle_arm_hw_error(struct acpi_hest_generic_data *gdata,
 			continue;
 		}
 
-		if (err_info->type < ARRAY_SIZE(cper_proc_error_type_strs))
-			error_type = cper_proc_error_type_strs[err_info->type];
+		cper_bits_to_str(error_type, sizeof(error_type),
+				 FIELD_GET(CPER_ARM_ERR_TYPE_MASK, err_info->type),
+				 cper_proc_error_type_strs,
+				 ARRAY_SIZE(cper_proc_error_type_strs));
 
 		pr_warn_ratelimited(FW_WARN GHES_PFX
-				    "Unhandled processor error type: %s\n",
-				    error_type);
+				    "Unhandled processor error type 0x%02x: %s%s\n",
+				    err_info->type, error_type,
+				    (err_info->type & ~CPER_ARM_ERR_TYPE_MASK) ? " with reserved bit(s)" : "");
 		p += err_info->length;
 	}
 
diff --git a/drivers/firmware/efi/cper-arm.c b/drivers/firmware/efi/cper-arm.c
index 6ff781e47147..76542a53e202 100644
--- a/drivers/firmware/efi/cper-arm.c
+++ b/drivers/firmware/efi/cper-arm.c
@@ -93,15 +93,11 @@ static void cper_print_arm_err_info(const char *pfx, u32 type,
 	bool proc_context_corrupt, corrected, precise_pc, restartable_pc;
 	bool time_out, access_mode;
 
-	/* If the type is unknown, bail. */
-	if (type > CPER_ARM_MAX_TYPE)
-		return;
-
 	/*
 	 * Vendor type errors have error information values that are vendor
 	 * specific.
 	 */
-	if (type == CPER_ARM_VENDOR_ERROR)
+	if (type & CPER_ARM_VENDOR_ERROR)
 		return;
 
 	if (error_info & CPER_ARM_ERR_VALID_TRANSACTION_TYPE) {
@@ -116,43 +112,38 @@ static void cper_print_arm_err_info(const char *pfx, u32 type,
 	if (error_info & CPER_ARM_ERR_VALID_OPERATION_TYPE) {
 		op_type = ((error_info >> CPER_ARM_ERR_OPERATION_SHIFT)
 			   & CPER_ARM_ERR_OPERATION_MASK);
-		switch (type) {
-		case CPER_ARM_CACHE_ERROR:
+		if (type & CPER_ARM_CACHE_ERROR) {
 			if (op_type < ARRAY_SIZE(arm_cache_err_op_strs)) {
-				printk("%soperation type: %s\n", pfx,
+				printk("%scache error, operation type: %s\n", pfx,
 				       arm_cache_err_op_strs[op_type]);
 			}
-			break;
-		case CPER_ARM_TLB_ERROR:
+		}
+		if (type & CPER_ARM_TLB_ERROR) {
 			if (op_type < ARRAY_SIZE(arm_tlb_err_op_strs)) {
-				printk("%soperation type: %s\n", pfx,
+				printk("%sTLB error, operation type: %s\n", pfx,
 				       arm_tlb_err_op_strs[op_type]);
 			}
-			break;
-		case CPER_ARM_BUS_ERROR:
+		}
+		if (type & CPER_ARM_BUS_ERROR) {
 			if (op_type < ARRAY_SIZE(arm_bus_err_op_strs)) {
-				printk("%soperation type: %s\n", pfx,
+				printk("%sbus error, operation type: %s\n", pfx,
 				       arm_bus_err_op_strs[op_type]);
 			}
-			break;
 		}
 	}
 
 	if (error_info & CPER_ARM_ERR_VALID_LEVEL) {
 		level = ((error_info >> CPER_ARM_ERR_LEVEL_SHIFT)
 			 & CPER_ARM_ERR_LEVEL_MASK);
-		switch (type) {
-		case CPER_ARM_CACHE_ERROR:
+		if (type & CPER_ARM_CACHE_ERROR)
 			printk("%scache level: %d\n", pfx, level);
-			break;
-		case CPER_ARM_TLB_ERROR:
+
+		if (type & CPER_ARM_TLB_ERROR)
 			printk("%sTLB level: %d\n", pfx, level);
-			break;
-		case CPER_ARM_BUS_ERROR:
+
+		if (type & CPER_ARM_BUS_ERROR)
 			printk("%saffinity level at which the bus error occurred: %d\n",
 			       pfx, level);
-			break;
-		}
 	}
 
 	if (error_info & CPER_ARM_ERR_VALID_PROC_CONTEXT_CORRUPT) {
@@ -241,6 +232,7 @@ void cper_print_proc_arm(const char *pfx,
 	struct cper_arm_err_info *err_info;
 	struct cper_arm_ctx_info *ctx_info;
 	char newpfx[64], infopfx[ARRAY_SIZE(newpfx) + 1];
+	char error_type[120];
 
 	printk("%sMIDR: 0x%016llx\n", pfx, proc->midr);
 
@@ -289,9 +281,15 @@ void cper_print_proc_arm(const char *pfx,
 				       newpfx);
 		}
 
-		printk("%serror_type: %d, %s\n", newpfx, err_info->type,
-			err_info->type < ARRAY_SIZE(cper_proc_error_type_strs) ?
-			cper_proc_error_type_strs[err_info->type] : "unknown");
+		cper_bits_to_str(error_type, sizeof(error_type),
+				 FIELD_GET(CPER_ARM_ERR_TYPE_MASK, err_info->type),
+				 cper_proc_error_type_strs,
+				 ARRAY_SIZE(cper_proc_error_type_strs));
+
+		printk("%serror_type: 0x%02x: %s%s\n", newpfx, err_info->type,
+		       error_type,
+		       (err_info->type & ~CPER_ARM_ERR_TYPE_MASK) ? " with reserved bit(s)" : "");
+
 		if (err_info->validation_bits & CPER_ARM_INFO_VALID_ERR_INFO) {
 			printk("%serror_info: 0x%016llx\n", newpfx,
 			       err_info->error_info);
diff --git a/include/linux/cper.h b/include/linux/cper.h
index 58f40477c824..5b1236d8c65b 100644
--- a/include/linux/cper.h
+++ b/include/linux/cper.h
@@ -297,11 +297,11 @@ enum {
 #define CPER_ARM_INFO_FLAGS_PROPAGATED		BIT(2)
 #define CPER_ARM_INFO_FLAGS_OVERFLOW		BIT(3)
 
-#define CPER_ARM_CACHE_ERROR			0
-#define CPER_ARM_TLB_ERROR			1
-#define CPER_ARM_BUS_ERROR			2
-#define CPER_ARM_VENDOR_ERROR			3
-#define CPER_ARM_MAX_TYPE			CPER_ARM_VENDOR_ERROR
+#define CPER_ARM_ERR_TYPE_MASK			GENMASK(4,1)
+#define CPER_ARM_CACHE_ERROR			BIT(1)
+#define CPER_ARM_TLB_ERROR			BIT(2)
+#define CPER_ARM_BUS_ERROR			BIT(3)
+#define CPER_ARM_VENDOR_ERROR			BIT(4)
 
 #define CPER_ARM_ERR_VALID_TRANSACTION_TYPE	BIT(0)
 #define CPER_ARM_ERR_VALID_OPERATION_TYPE	BIT(1)

From 7a2ff00c3b5e3ca1bbeb13cda52efe870be8501b Mon Sep 17 00:00:00 2001
From: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Date: Thu, 14 Aug 2025 09:52:56 -0700
Subject: [PATCH 14/14] docs: efi: add CPER functions to driver-api

There are two kernel-doc like descriptions at cper, which is used
by other parts of cper and on ghes driver. They both have kernel-doc
like descriptions.

Change the tags for them to be actual kernel-doc tags and add them
to the driver-api documentaion at the UEFI section.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 Documentation/driver-api/firmware/efi/index.rst | 11 ++++++++---
 drivers/firmware/efi/cper.c                     |  2 +-
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/Documentation/driver-api/firmware/efi/index.rst b/Documentation/driver-api/firmware/efi/index.rst
index 4fe8abba9fc6..5a6b6229592c 100644
--- a/Documentation/driver-api/firmware/efi/index.rst
+++ b/Documentation/driver-api/firmware/efi/index.rst
@@ -1,11 +1,16 @@
 .. SPDX-License-Identifier: GPL-2.0
 
-============
-UEFI Support
-============
+====================================================
+Unified Extensible Firmware Interface (UEFI) Support
+====================================================
 
 UEFI stub library functions
 ===========================
 
 .. kernel-doc:: drivers/firmware/efi/libstub/mem.c
    :internal:
+
+UEFI Common Platform Error Record (CPER) functions
+==================================================
+
+.. kernel-doc:: drivers/firmware/efi/cper.c
diff --git a/drivers/firmware/efi/cper.c b/drivers/firmware/efi/cper.c
index 79ba688a64f8..0232bd040f61 100644
--- a/drivers/firmware/efi/cper.c
+++ b/drivers/firmware/efi/cper.c
@@ -70,7 +70,7 @@ const char *cper_severity_str(unsigned int severity)
 }
 EXPORT_SYMBOL_GPL(cper_severity_str);
 
-/*
+/**
  * cper_print_bits - print strings for set bits
  * @pfx: prefix for each line, including log level and prefix string
  * @bits: bit mask