On Tue, Nov 21, 2017 at 01:40:17PM +0000, Ard Biesheuvel wrote: > Most crypto drivers involving kernel mode NEON take care to put the code > that actually touches the NEON register file in a separate compilation > unit, to prevent the compiler from reordering code that preserves or > restores the NEON context with code that may corrupt it. This is > necessary because we currently have no way to express the restrictions > imposed upon use of the NEON in kernel mode in a way that the compiler > understands. > > However, in the case of aes-ce-cipher, it did not seem unreasonable to > deviate from this rule, given how it does not seem possible for the > compiler to reorder cross object function calls with asm blocks whose > in- and output constraints reflect that it reads from and writes to > memory. > > Now that LTO is being proposed for the arm64 kernel, it is time to > revisit this. The link time optimization may replace the function > calls to kernel_neon_begin() and kernel_neon_end() with instantiations > of the IR that make up its implementation, allowing further reordering > with the asm block. > > So let's clean this up, and move the asm() blocks into a separate .S > file. > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> Patch applied. Thanks. -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
