lib/crypto: arm64/sha3: Remove obsolete chunking logic

Since commit aefbab8e77eb ("arm64: fpsimd: Preserve/restore kernel mode
NEON at context switch"), kernel-mode NEON sections have been
preemptible on arm64.  And since commit 7dadeaa6e851 ("sched: Further
restrict the preemption modes"), voluntary preemption is no longer
supported on arm64 either.  Therefore, there's no longer any need to
limit the length of kernel-mode NEON sections on arm64.

Simplify the SHA-3 code accordingly.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260401000548.133151-9-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>

diff --git a/lib/crypto/arm64/sha3-ce-core.S b/lib/crypto/arm64/sha3-ce-core.S
index ace90b506490ca7bf6d5756ec0b3876186068ae3..b8ab01987ae076b760c58111ef0d3033e1d8e7b6 100644 (file)
--- a/lib/crypto/arm64/sha3-ce-core.S
+++ b/lib/crypto/arm64/sha3-ce-core.S
@@ -37,8 +37,8 @@
        .endm
 
        /*
-        * size_t sha3_ce_transform(struct sha3_state *state, const u8 *data,
-        *                          size_t nblocks, size_t block_size)
+        * void sha3_ce_transform(struct sha3_state *state, const u8 *data,
+        *                        size_t nblocks, size_t block_size)
         *
         * block_size is assumed to be one of 72 (SHA3-512), 104 (SHA3-384), 136
         * (SHA3-256 and SHAKE256), 144 (SHA3-224), or 168 (SHAKE128).
@@ -185,18 +185,16 @@ SYM_FUNC_START(sha3_ce_transform)
        eor      v0.16b,  v0.16b, v31.16b
 
        cbnz    w8, 3b
-       cond_yield 4f, x8, x9
        cbnz    x2, 0b
 
        /* save state */
-4:     st1     { v0.1d- v3.1d}, [x0], #32
+       st1     { v0.1d- v3.1d}, [x0], #32
        st1     { v4.1d- v7.1d}, [x0], #32
        st1     { v8.1d-v11.1d}, [x0], #32
        st1     {v12.1d-v15.1d}, [x0], #32
        st1     {v16.1d-v19.1d}, [x0], #32
        st1     {v20.1d-v23.1d}, [x0], #32
        st1     {v24.1d}, [x0]
-       mov     x0, x2
        ret
 SYM_FUNC_END(sha3_ce_transform)
 

diff --git a/lib/crypto/arm64/sha3.h b/lib/crypto/arm64/sha3.h
index b602f1b3b2822e510b1ffbed2af30f5639b1ac37..eaaba3224acc1bb91adb3618802689da61d3ddf2 100644 (file)
--- a/lib/crypto/arm64/sha3.h
+++ b/lib/crypto/arm64/sha3.h
@@ -12,22 +12,15 @@
 
 static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_sha3);
 
-asmlinkage size_t sha3_ce_transform(struct sha3_state *state, const u8 *data,
-                                   size_t nblocks, size_t block_size);
+asmlinkage void sha3_ce_transform(struct sha3_state *state, const u8 *data,
+                                 size_t nblocks, size_t block_size);
 
 static void sha3_absorb_blocks(struct sha3_state *state, const u8 *data,
                               size_t nblocks, size_t block_size)
 {
        if (static_branch_likely(&have_sha3) && likely(may_use_simd())) {
-               do {
-                       size_t rem;
-
-                       scoped_ksimd()
-                               rem = sha3_ce_transform(state, data, nblocks,
-                                                       block_size);
-                       data += (nblocks - rem) * block_size;
-                       nblocks = rem;
-               } while (nblocks);
+               scoped_ksimd()
+                       sha3_ce_transform(state, data, nblocks, block_size);
        } else {
                sha3_absorb_blocks_generic(state, data, nblocks, block_size);
        }