1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * SHA-1 optimized for x86_64
4  *
5  * Copyright 2025 Google LLC
6  */
7 #include <asm/fpu/api.h>
8 #include <linux/static_call.h>
9 
10 DEFINE_STATIC_CALL(sha1_blocks_x86, sha1_blocks_generic);
11 
12 #define DEFINE_X86_SHA1_FN(c_fn, asm_fn)                           \
13 	asmlinkage void asm_fn(struct sha1_block_state *state,     \
14 			       const u8 *data, size_t nblocks);    \
15 	static void c_fn(struct sha1_block_state *state,           \
16 			 const u8 *data, size_t nblocks)           \
17 	{                                                          \
18 		if (likely(irq_fpu_usable())) {                    \
19 			kernel_fpu_begin();                        \
20 			asm_fn(state, data, nblocks);              \
21 			kernel_fpu_end();                          \
22 		} else {                                           \
23 			sha1_blocks_generic(state, data, nblocks); \
24 		}                                                  \
25 	}
26 
27 DEFINE_X86_SHA1_FN(sha1_blocks_ssse3, sha1_transform_ssse3);
28 DEFINE_X86_SHA1_FN(sha1_blocks_avx, sha1_transform_avx);
29 DEFINE_X86_SHA1_FN(sha1_blocks_ni, sha1_ni_transform);
30 
31 #define SHA1_AVX2_BLOCK_OPTSIZE 4 /* optimal 4*64 bytes of SHA1 blocks */
32 
33 asmlinkage void sha1_transform_avx2(struct sha1_block_state *state,
34 				    const u8 *data, size_t nblocks);
sha1_blocks_avx2(struct sha1_block_state * state,const u8 * data,size_t nblocks)35 static void sha1_blocks_avx2(struct sha1_block_state *state,
36 			     const u8 *data, size_t nblocks)
37 {
38 	if (likely(irq_fpu_usable())) {
39 		kernel_fpu_begin();
40 		/* Select the optimal transform based on the number of blocks */
41 		if (nblocks >= SHA1_AVX2_BLOCK_OPTSIZE)
42 			sha1_transform_avx2(state, data, nblocks);
43 		else
44 			sha1_transform_avx(state, data, nblocks);
45 		kernel_fpu_end();
46 	} else {
47 		sha1_blocks_generic(state, data, nblocks);
48 	}
49 }
50 
sha1_blocks(struct sha1_block_state * state,const u8 * data,size_t nblocks)51 static void sha1_blocks(struct sha1_block_state *state,
52 			const u8 *data, size_t nblocks)
53 {
54 	static_call(sha1_blocks_x86)(state, data, nblocks);
55 }
56 
57 #define sha1_mod_init_arch sha1_mod_init_arch
sha1_mod_init_arch(void)58 static inline void sha1_mod_init_arch(void)
59 {
60 	if (boot_cpu_has(X86_FEATURE_SHA_NI)) {
61 		static_call_update(sha1_blocks_x86, sha1_blocks_ni);
62 	} else if (cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM,
63 				     NULL) &&
64 		   boot_cpu_has(X86_FEATURE_AVX)) {
65 		if (boot_cpu_has(X86_FEATURE_AVX2) &&
66 		    boot_cpu_has(X86_FEATURE_BMI1) &&
67 		    boot_cpu_has(X86_FEATURE_BMI2))
68 			static_call_update(sha1_blocks_x86, sha1_blocks_avx2);
69 		else
70 			static_call_update(sha1_blocks_x86, sha1_blocks_avx);
71 	} else if (boot_cpu_has(X86_FEATURE_SSSE3)) {
72 		static_call_update(sha1_blocks_x86, sha1_blocks_ssse3);
73 	}
74 }
75