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Ard Biesheuvel authored
When the ARM accelerated ChaCha driver is built as part of a configuration that has kernel mode NEON disabled, we expect the compiler to propagate the build time constant expression IS_ENABLED(CONFIG_KERNEL_MODE_NEON) in a way that eliminates all the cross-object references to the actual NEON routines, which allows the chacha-neon-core.o object to be omitted from the build entirely. Unfortunately, this fails to work as expected in some cases, and we may end up with a build error such as chacha-glue.c:(.text+0xc0): undefined reference to `chacha_4block_xor_neon' caused by the fact that chacha_doneon() has not been eliminated from the object code, even though it will never be called in practice. Let's fix this by adding some IS_ENABLED(CONFIG_KERNEL_MODE_NEON) tests that are not strictly needed from a logical point of view, but should help the compiler infer that the NEON code paths are unreachable in those cases. Fixes: b36d8c09 ("crypto: arm/chacha - remove dependency on generic ...") Reported-by: Russell King <linux@armlinux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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