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Diffstat (limited to 'lib/crypto/powerpc/sha1.h')
-rw-r--r-- | lib/crypto/powerpc/sha1.h | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/lib/crypto/powerpc/sha1.h b/lib/crypto/powerpc/sha1.h new file mode 100644 index 000000000000..e2c010f0370b --- /dev/null +++ b/lib/crypto/powerpc/sha1.h @@ -0,0 +1,67 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * SHA-1 optimized for PowerPC + * + * Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de> + */ + +#include <asm/switch_to.h> +#include <linux/preempt.h> + +#ifdef CONFIG_SPE +/* + * MAX_BYTES defines the number of bytes that are allowed to be processed + * between preempt_disable() and preempt_enable(). SHA1 takes ~1000 + * operations per 64 bytes. e500 cores can issue two arithmetic instructions + * per clock cycle using one 32/64 bit unit (SU1) and one 32 bit unit (SU2). + * Thus 2KB of input data will need an estimated maximum of 18,000 cycles. + * Headroom for cache misses included. Even with the low end model clocked + * at 667 MHz this equals to a critical time window of less than 27us. + * + */ +#define MAX_BYTES 2048 + +asmlinkage void ppc_spe_sha1_transform(struct sha1_block_state *state, + const u8 *data, u32 nblocks); + +static void spe_begin(void) +{ + /* We just start SPE operations and will save SPE registers later. */ + preempt_disable(); + enable_kernel_spe(); +} + +static void spe_end(void) +{ + disable_kernel_spe(); + /* reenable preemption */ + preempt_enable(); +} + +static void sha1_blocks(struct sha1_block_state *state, + const u8 *data, size_t nblocks) +{ + do { + u32 unit = min_t(size_t, nblocks, MAX_BYTES / SHA1_BLOCK_SIZE); + + spe_begin(); + ppc_spe_sha1_transform(state, data, unit); + spe_end(); + + data += unit * SHA1_BLOCK_SIZE; + nblocks -= unit; + } while (nblocks); +} +#else /* CONFIG_SPE */ +asmlinkage void powerpc_sha_transform(struct sha1_block_state *state, + const u8 data[SHA1_BLOCK_SIZE]); + +static void sha1_blocks(struct sha1_block_state *state, + const u8 *data, size_t nblocks) +{ + do { + powerpc_sha_transform(state, data); + data += SHA1_BLOCK_SIZE; + } while (--nblocks); +} +#endif /* !CONFIG_SPE */ |