Re: [PATCH crypto-stable] crypto: arch/lib - limit simd usage to PAGE_SIZE chunks

On Tue, Apr 21, 2020 at 10:04 PM Eric Biggers ebiggers@kernel.org wrote:

Seems this should just be a 'while' loop?

    while (bytes) {
            unsigned int todo = min_t(unsigned int, PAGE_SIZE, bytes);

            kernel_neon_begin();
            chacha_doneon(state, dst, src, todo, nrounds);
            kernel_neon_end();

            bytes -= todo;
            src += todo;
            dst += todo;
    }

The for(;;) is how it's done elsewhere in the kernel (that this patch doesn't touch), because then we can break out of the loop before having to increment src and dst unnecessarily. Likely a pointless optimization as probably the compiler can figure out how to avoid that. But maybe it can't. If you have a strong preference, I can reactor everything to use `while (bytes)`, but if you don't care, let's keep this as-is. Opinion?

Jason