Merge tag 'efi-next-for-v6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi

Pull EFI updates from Ard Biesheuvel:
 "The usual trickle of EFI contributions:

   - Parse SMBIOS tables in memory directly on Macbooks that do not
     implement the EFI SMBIOS protocol

   - Obtain EDID information from the primary display while running in
     the EFI stub, and expose it via bootparams on x86 (generic method
     is in the works, and will likely land during the next cycle)

   - Bring CPER handling for ARM systems up to data with the latest EFI
     spec changes

   - Various cosmetic changes"

* tag 'efi-next-for-v6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  docs: efi: add CPER functions to driver-api
  efi/cper: align ARM CPER type with UEFI 2.9A/2.10 specs
  efi/cper: Add a new helper function to print bitmasks
  efi/cper: Adjust infopfx size to accept an extra space
  RAS: Report all ARM processor CPER information to userspace
  efi/libstub: x86: Store EDID in boot_params
  efi/libstub: gop: Add support for reading EDID
  efi/libstub: gop: Initialize screen_info in helper function
  efi/libstub: gop: Find GOP handle instead of GOP data
  efi: Fix trailing whitespace in header file
  efi/memattr: Convert efi_memattr_init() return type to void
  efi: stmm: fix kernel-doc "bad line" warnings
  efi/riscv: Remove the useless failure return message print
  efistub/x86: Add fallback for SMBIOS record lookup

1 files changed, 102 insertions, 2 deletions

diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c
index 761121a77f9e..cef32e2c82d8 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;
 
@@ -388,8 +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_gop(si);
+	efi_setup_graphics(si, edid);
 }
 
 static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status)