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