Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) #include <linux/io.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) #include <linux/export.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  *	check_signature		-	find BIOS signatures
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7)  *	@io_addr: mmio address to check
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8)  *	@signature:  signature block
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9)  *	@length: length of signature
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)  *	Perform a signature comparison with the mmio address io_addr. This
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)  *	address should have been obtained by ioremap.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)  *	Returns 1 on a match.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) int check_signature(const volatile void __iomem *io_addr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 			const unsigned char *signature, int length)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 	while (length--) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 		if (readb(io_addr) != *signature)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 			return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 		io_addr++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 		signature++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 	return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) EXPORT_SYMBOL(check_signature);