linux/lib/crc/crc-t10dif-main.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* T10 Data Integrity Field CRC16 calculation
*
* Copyright (c) 2007 Oracle Corporation. All rights reserved.
* Written by Martin K. Petersen <martin.petersen@oracle.com>
*/
#include <linux/crc-t10dif.h>
#include <linux/export.h>
#include <linux/module.h>
#include <linux/types.h>
/*
* Table generated using the following polynomial:
* x^16 + x^15 + x^11 + x^9 + x^8 + x^7 + x^5 + x^4 + x^2 + x + 1
* gt: 0x8bb7
*/
static const u16 t10_dif_crc_table[256] = {
0x0000, 0x8BB7, 0x9CD9, 0x176E, 0xB205, 0x39B2, 0x2EDC, 0xA56B,
0xEFBD, 0x640A, 0x7364, 0xF8D3, 0x5DB8, 0xD60F, 0xC161, 0x4AD6,
0x54CD, 0xDF7A, 0xC814, 0x43A3, 0xE6C8, 0x6D7F, 0x7A11, 0xF1A6,
0xBB70, 0x30C7, 0x27A9, 0xAC1E, 0x0975, 0x82C2, 0x95AC, 0x1E1B,
0xA99A, 0x222D, 0x3543, 0xBEF4, 0x1B9F, 0x9028, 0x8746, 0x0CF1,
0x4627, 0xCD90, 0xDAFE, 0x5149, 0xF422, 0x7F95, 0x68FB, 0xE34C,
0xFD57, 0x76E0, 0x618E, 0xEA39, 0x4F52, 0xC4E5, 0xD38B, 0x583C,
0x12EA, 0x995D, 0x8E33, 0x0584, 0xA0EF, 0x2B58, 0x3C36, 0xB781,
0xD883, 0x5334, 0x445A, 0xCFED, 0x6A86, 0xE131, 0xF65F, 0x7DE8,
0x373E, 0xBC89, 0xABE7, 0x2050, 0x853B, 0x0E8C, 0x19E2, 0x9255,
0x8C4E, 0x07F9, 0x1097, 0x9B20, 0x3E4B, 0xB5FC, 0xA292, 0x2925,
0x63F3, 0xE844, 0xFF2A, 0x749D, 0xD1F6, 0x5A41, 0x4D2F, 0xC698,
0x7119, 0xFAAE, 0xEDC0, 0x6677, 0xC31C, 0x48AB, 0x5FC5, 0xD472,
0x9EA4, 0x1513, 0x027D, 0x89CA, 0x2CA1, 0xA716, 0xB078, 0x3BCF,
0x25D4, 0xAE63, 0xB90D, 0x32BA, 0x97D1, 0x1C66, 0x0B08, 0x80BF,
0xCA69, 0x41DE, 0x56B0, 0xDD07, 0x786C, 0xF3DB, 0xE4B5, 0x6F02,
0x3AB1, 0xB106, 0xA668, 0x2DDF, 0x88B4, 0x0303, 0x146D, 0x9FDA,
0xD50C, 0x5EBB, 0x49D5, 0xC262, 0x6709, 0xECBE, 0xFBD0, 0x7067,
0x6E7C, 0xE5CB, 0xF2A5, 0x7912, 0xDC79, 0x57CE, 0x40A0, 0xCB17,
0x81C1, 0x0A76, 0x1D18, 0x96AF, 0x33C4, 0xB873, 0xAF1D, 0x24AA,
0x932B, 0x189C, 0x0FF2, 0x8445, 0x212E, 0xAA99, 0xBDF7, 0x3640,
0x7C96, 0xF721, 0xE04F, 0x6BF8, 0xCE93, 0x4524, 0x524A, 0xD9FD,
0xC7E6, 0x4C51, 0x5B3F, 0xD088, 0x75E3, 0xFE54, 0xE93A, 0x628D,
0x285B, 0xA3EC, 0xB482, 0x3F35, 0x9A5E, 0x11E9, 0x0687, 0x8D30,
0xE232, 0x6985, 0x7EEB, 0xF55C, 0x5037, 0xDB80, 0xCCEE, 0x4759,
0x0D8F, 0x8638, 0x9156, 0x1AE1, 0xBF8A, 0x343D, 0x2353, 0xA8E4,
0xB6FF, 0x3D48, 0x2A26, 0xA191, 0x04FA, 0x8F4D, 0x9823, 0x1394,
0x5942, 0xD2F5, 0xC59B, 0x4E2C, 0xEB47, 0x60F0, 0x779E, 0xFC29,
0x4BA8, 0xC01F, 0xD771, 0x5CC6, 0xF9AD, 0x721A, 0x6574, 0xEEC3,
0xA415, 0x2FA2, 0x38CC, 0xB37B, 0x1610, 0x9DA7, 0x8AC9, 0x017E,
0x1F65, 0x94D2, 0x83BC, 0x080B, 0xAD60, 0x26D7, 0x31B9, 0xBA0E,
0xF0D8, 0x7B6F, 0x6C01, 0xE7B6, 0x42DD, 0xC96A, 0xDE04, 0x55B3
};
lib/crc: Prepare for arch-optimized code in subdirs of lib/crc/ Rework how lib/crc/ supports arch-optimized code. First, instead of the arch-optimized CRC code being in arch/$(SRCARCH)/lib/, it will now be in lib/crc/$(SRCARCH)/. Second, the API functions (e.g. crc32c()), arch-optimized functions (e.g. crc32c_arch()), and generic functions (e.g. crc32c_base()) will now be part of a single module for each CRC type, allowing better inlining and dead code elimination. The second change is made possible by the first. As an example, consider CONFIG_CRC32=m on x86. We'll now have just crc32.ko instead of both crc32-x86.ko and crc32.ko. The two modules were already coupled together and always both got loaded together via direct symbol dependency, so the separation provided no benefit. Note: later I'd like to apply the same design to lib/crypto/ too, where often the API functions are out-of-line so this will work even better. In those cases, for each algorithm we currently have 3 modules all coupled together, e.g. libsha256.ko, libsha256-generic.ko, and sha256-x86.ko. We should have just one, inline things properly, and rely on the compiler's dead code elimination to decide the inclusion of the generic code instead of manually setting it via kconfig. Having arch-specific code outside arch/ was somewhat controversial when Zinc proposed it back in 2018. But I don't think the concerns are warranted. It's better from a technical perspective, as it enables the improvements mentioned above. This model is already successfully used in other places in the kernel such as lib/raid6/. The community of each architecture still remains free to work on the code, even if it's not in arch/. At the time there was also a desire to put the library code in the same files as the old-school crypto API, but that was a mistake; now that the library is separate, that's no longer a constraint either. Reviewed-by: "Martin K. Petersen" <martin.petersen@oracle.com> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: "Jason A. Donenfeld" <Jason@zx2c4.com> Link: https://lore.kernel.org/r/20250607200454.73587-3-ebiggers@kernel.org Link: https://lore.kernel.org/r/20250612054514.142728-1-ebiggers@kernel.org Link: https://lore.kernel.org/r/20250621012221.4351-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2025-06-07 13:04:44 -07:00
static inline u16 __maybe_unused
crc_t10dif_generic(u16 crc, const u8 *p, size_t len)
{
lib/crc: Prepare for arch-optimized code in subdirs of lib/crc/ Rework how lib/crc/ supports arch-optimized code. First, instead of the arch-optimized CRC code being in arch/$(SRCARCH)/lib/, it will now be in lib/crc/$(SRCARCH)/. Second, the API functions (e.g. crc32c()), arch-optimized functions (e.g. crc32c_arch()), and generic functions (e.g. crc32c_base()) will now be part of a single module for each CRC type, allowing better inlining and dead code elimination. The second change is made possible by the first. As an example, consider CONFIG_CRC32=m on x86. We'll now have just crc32.ko instead of both crc32-x86.ko and crc32.ko. The two modules were already coupled together and always both got loaded together via direct symbol dependency, so the separation provided no benefit. Note: later I'd like to apply the same design to lib/crypto/ too, where often the API functions are out-of-line so this will work even better. In those cases, for each algorithm we currently have 3 modules all coupled together, e.g. libsha256.ko, libsha256-generic.ko, and sha256-x86.ko. We should have just one, inline things properly, and rely on the compiler's dead code elimination to decide the inclusion of the generic code instead of manually setting it via kconfig. Having arch-specific code outside arch/ was somewhat controversial when Zinc proposed it back in 2018. But I don't think the concerns are warranted. It's better from a technical perspective, as it enables the improvements mentioned above. This model is already successfully used in other places in the kernel such as lib/raid6/. The community of each architecture still remains free to work on the code, even if it's not in arch/. At the time there was also a desire to put the library code in the same files as the old-school crypto API, but that was a mistake; now that the library is separate, that's no longer a constraint either. Reviewed-by: "Martin K. Petersen" <martin.petersen@oracle.com> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: "Jason A. Donenfeld" <Jason@zx2c4.com> Link: https://lore.kernel.org/r/20250607200454.73587-3-ebiggers@kernel.org Link: https://lore.kernel.org/r/20250612054514.142728-1-ebiggers@kernel.org Link: https://lore.kernel.org/r/20250621012221.4351-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2025-06-07 13:04:44 -07:00
while (len--)
crc = (crc << 8) ^ t10_dif_crc_table[(crc >> 8) ^ *p++];
return crc;
}
lib/crc: Prepare for arch-optimized code in subdirs of lib/crc/ Rework how lib/crc/ supports arch-optimized code. First, instead of the arch-optimized CRC code being in arch/$(SRCARCH)/lib/, it will now be in lib/crc/$(SRCARCH)/. Second, the API functions (e.g. crc32c()), arch-optimized functions (e.g. crc32c_arch()), and generic functions (e.g. crc32c_base()) will now be part of a single module for each CRC type, allowing better inlining and dead code elimination. The second change is made possible by the first. As an example, consider CONFIG_CRC32=m on x86. We'll now have just crc32.ko instead of both crc32-x86.ko and crc32.ko. The two modules were already coupled together and always both got loaded together via direct symbol dependency, so the separation provided no benefit. Note: later I'd like to apply the same design to lib/crypto/ too, where often the API functions are out-of-line so this will work even better. In those cases, for each algorithm we currently have 3 modules all coupled together, e.g. libsha256.ko, libsha256-generic.ko, and sha256-x86.ko. We should have just one, inline things properly, and rely on the compiler's dead code elimination to decide the inclusion of the generic code instead of manually setting it via kconfig. Having arch-specific code outside arch/ was somewhat controversial when Zinc proposed it back in 2018. But I don't think the concerns are warranted. It's better from a technical perspective, as it enables the improvements mentioned above. This model is already successfully used in other places in the kernel such as lib/raid6/. The community of each architecture still remains free to work on the code, even if it's not in arch/. At the time there was also a desire to put the library code in the same files as the old-school crypto API, but that was a mistake; now that the library is separate, that's no longer a constraint either. Reviewed-by: "Martin K. Petersen" <martin.petersen@oracle.com> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: "Jason A. Donenfeld" <Jason@zx2c4.com> Link: https://lore.kernel.org/r/20250607200454.73587-3-ebiggers@kernel.org Link: https://lore.kernel.org/r/20250612054514.142728-1-ebiggers@kernel.org Link: https://lore.kernel.org/r/20250621012221.4351-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2025-06-07 13:04:44 -07:00
#ifdef CONFIG_CRC_T10DIF_ARCH
#include "crc-t10dif.h" /* $(SRCARCH)/crc-t10dif.h */
#else
#define crc_t10dif_arch crc_t10dif_generic
#endif
lib/crc: Prepare for arch-optimized code in subdirs of lib/crc/ Rework how lib/crc/ supports arch-optimized code. First, instead of the arch-optimized CRC code being in arch/$(SRCARCH)/lib/, it will now be in lib/crc/$(SRCARCH)/. Second, the API functions (e.g. crc32c()), arch-optimized functions (e.g. crc32c_arch()), and generic functions (e.g. crc32c_base()) will now be part of a single module for each CRC type, allowing better inlining and dead code elimination. The second change is made possible by the first. As an example, consider CONFIG_CRC32=m on x86. We'll now have just crc32.ko instead of both crc32-x86.ko and crc32.ko. The two modules were already coupled together and always both got loaded together via direct symbol dependency, so the separation provided no benefit. Note: later I'd like to apply the same design to lib/crypto/ too, where often the API functions are out-of-line so this will work even better. In those cases, for each algorithm we currently have 3 modules all coupled together, e.g. libsha256.ko, libsha256-generic.ko, and sha256-x86.ko. We should have just one, inline things properly, and rely on the compiler's dead code elimination to decide the inclusion of the generic code instead of manually setting it via kconfig. Having arch-specific code outside arch/ was somewhat controversial when Zinc proposed it back in 2018. But I don't think the concerns are warranted. It's better from a technical perspective, as it enables the improvements mentioned above. This model is already successfully used in other places in the kernel such as lib/raid6/. The community of each architecture still remains free to work on the code, even if it's not in arch/. At the time there was also a desire to put the library code in the same files as the old-school crypto API, but that was a mistake; now that the library is separate, that's no longer a constraint either. Reviewed-by: "Martin K. Petersen" <martin.petersen@oracle.com> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: "Jason A. Donenfeld" <Jason@zx2c4.com> Link: https://lore.kernel.org/r/20250607200454.73587-3-ebiggers@kernel.org Link: https://lore.kernel.org/r/20250612054514.142728-1-ebiggers@kernel.org Link: https://lore.kernel.org/r/20250621012221.4351-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2025-06-07 13:04:44 -07:00
u16 crc_t10dif_update(u16 crc, const u8 *p, size_t len)
{
return crc_t10dif_arch(crc, p, len);
}
EXPORT_SYMBOL(crc_t10dif_update);
#ifdef crc_t10dif_mod_init_arch
static int __init crc_t10dif_mod_init(void)
{
crc_t10dif_mod_init_arch();
return 0;
}
subsys_initcall(crc_t10dif_mod_init);
static void __exit crc_t10dif_mod_exit(void)
{
}
lib/crc: Prepare for arch-optimized code in subdirs of lib/crc/ Rework how lib/crc/ supports arch-optimized code. First, instead of the arch-optimized CRC code being in arch/$(SRCARCH)/lib/, it will now be in lib/crc/$(SRCARCH)/. Second, the API functions (e.g. crc32c()), arch-optimized functions (e.g. crc32c_arch()), and generic functions (e.g. crc32c_base()) will now be part of a single module for each CRC type, allowing better inlining and dead code elimination. The second change is made possible by the first. As an example, consider CONFIG_CRC32=m on x86. We'll now have just crc32.ko instead of both crc32-x86.ko and crc32.ko. The two modules were already coupled together and always both got loaded together via direct symbol dependency, so the separation provided no benefit. Note: later I'd like to apply the same design to lib/crypto/ too, where often the API functions are out-of-line so this will work even better. In those cases, for each algorithm we currently have 3 modules all coupled together, e.g. libsha256.ko, libsha256-generic.ko, and sha256-x86.ko. We should have just one, inline things properly, and rely on the compiler's dead code elimination to decide the inclusion of the generic code instead of manually setting it via kconfig. Having arch-specific code outside arch/ was somewhat controversial when Zinc proposed it back in 2018. But I don't think the concerns are warranted. It's better from a technical perspective, as it enables the improvements mentioned above. This model is already successfully used in other places in the kernel such as lib/raid6/. The community of each architecture still remains free to work on the code, even if it's not in arch/. At the time there was also a desire to put the library code in the same files as the old-school crypto API, but that was a mistake; now that the library is separate, that's no longer a constraint either. Reviewed-by: "Martin K. Petersen" <martin.petersen@oracle.com> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: "Jason A. Donenfeld" <Jason@zx2c4.com> Link: https://lore.kernel.org/r/20250607200454.73587-3-ebiggers@kernel.org Link: https://lore.kernel.org/r/20250612054514.142728-1-ebiggers@kernel.org Link: https://lore.kernel.org/r/20250621012221.4351-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2025-06-07 13:04:44 -07:00
module_exit(crc_t10dif_mod_exit);
#endif
lib/crc: Prepare for arch-optimized code in subdirs of lib/crc/ Rework how lib/crc/ supports arch-optimized code. First, instead of the arch-optimized CRC code being in arch/$(SRCARCH)/lib/, it will now be in lib/crc/$(SRCARCH)/. Second, the API functions (e.g. crc32c()), arch-optimized functions (e.g. crc32c_arch()), and generic functions (e.g. crc32c_base()) will now be part of a single module for each CRC type, allowing better inlining and dead code elimination. The second change is made possible by the first. As an example, consider CONFIG_CRC32=m on x86. We'll now have just crc32.ko instead of both crc32-x86.ko and crc32.ko. The two modules were already coupled together and always both got loaded together via direct symbol dependency, so the separation provided no benefit. Note: later I'd like to apply the same design to lib/crypto/ too, where often the API functions are out-of-line so this will work even better. In those cases, for each algorithm we currently have 3 modules all coupled together, e.g. libsha256.ko, libsha256-generic.ko, and sha256-x86.ko. We should have just one, inline things properly, and rely on the compiler's dead code elimination to decide the inclusion of the generic code instead of manually setting it via kconfig. Having arch-specific code outside arch/ was somewhat controversial when Zinc proposed it back in 2018. But I don't think the concerns are warranted. It's better from a technical perspective, as it enables the improvements mentioned above. This model is already successfully used in other places in the kernel such as lib/raid6/. The community of each architecture still remains free to work on the code, even if it's not in arch/. At the time there was also a desire to put the library code in the same files as the old-school crypto API, but that was a mistake; now that the library is separate, that's no longer a constraint either. Reviewed-by: "Martin K. Petersen" <martin.petersen@oracle.com> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: "Jason A. Donenfeld" <Jason@zx2c4.com> Link: https://lore.kernel.org/r/20250607200454.73587-3-ebiggers@kernel.org Link: https://lore.kernel.org/r/20250612054514.142728-1-ebiggers@kernel.org Link: https://lore.kernel.org/r/20250621012221.4351-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2025-06-07 13:04:44 -07:00
MODULE_DESCRIPTION("CRC-T10DIF library functions");
MODULE_LICENSE("GPL");