crypto: arm64/sha256-neon - play nice with CONFIG_PREEMPT kernels (1a3713c7) · Commits · 戴 / test

arch/arm64/crypto/sha256-glue.c

+23 −13

Original line number	Diff line number	Diff line
		@@ -89,21 +89,32 @@ static struct shash_alg algs[] = { {
		static int sha256_update_neon(struct shash_desc desc, const u8 data,
		unsigned int len)
		{
		/*
		* Stacking and unstacking a substantial slice of the NEON register
		* file may significantly affect performance for small updates when
		* executing in interrupt context, so fall back to the scalar code
		* in that case.
		*/
		struct sha256_state *sctx = shash_desc_ctx(desc);

		if (!may_use_simd())
		return sha256_base_do_update(desc, data, len,
		(sha256_block_fn *)sha256_block_data_order);

		while (len > 0) {
		unsigned int chunk = len;

		/*
		* Don't hog the CPU for the entire time it takes to process all
		* input when running on a preemptible kernel, but process the
		* data block by block instead.
		*/
		if (IS_ENABLED(CONFIG_PREEMPT) &&
		chunk + sctx->count % SHA256_BLOCK_SIZE > SHA256_BLOCK_SIZE)
		chunk = SHA256_BLOCK_SIZE -
		sctx->count % SHA256_BLOCK_SIZE;

		kernel_neon_begin();
		sha256_base_do_update(desc, data, len,
		sha256_base_do_update(desc, data, chunk,
		(sha256_block_fn *)sha256_block_neon);
		kernel_neon_end();

		data += chunk;
		len -= chunk;
		}
		return 0;
		}

		@@ -117,10 +128,9 @@ static int sha256_finup_neon(struct shash_desc desc, const u8 data,
		sha256_base_do_finalize(desc,
		(sha256_block_fn *)sha256_block_data_order);
		} else {
		kernel_neon_begin();
		if (len)
		sha256_base_do_update(desc, data, len,
		(sha256_block_fn *)sha256_block_neon);
		sha256_update_neon(desc, data, len);
		kernel_neon_begin();
		sha256_base_do_finalize(desc,
		(sha256_block_fn *)sha256_block_neon);
		kernel_neon_end();

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