| Greg Kroah-Hartman | b244131 | 2017-11-01 15:07:57 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| Andrew Morton | cc2ea41 | 2007-07-15 23:41:38 -0700 | [diff] [blame] | 2 | #include <linux/io.h> |
| Paul Gortmaker | 8bc3bcc | 2011-11-16 21:29:17 -0500 | [diff] [blame] | 3 | #include <linux/export.h> |
| Andrew Morton | cc2ea41 | 2007-07-15 23:41:38 -0700 | [diff] [blame] | 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); |