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