| Message ID | 20180618223323.130072-1-ebiggers@google.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Herbert Xu |
| Headers | show |
On 19 June 2018 at 00:33, Eric Biggers <ebiggers@google.com> wrote: > Building the kernel with CONFIG_THUMB2_KERNEL=y and > CONFIG_CRYPTO_SPECK_NEON set fails with the following errors: > > arch/arm/crypto/speck-neon-core.S: Assembler messages: > > arch/arm/crypto/speck-neon-core.S:419: Error: r13 not allowed here -- `bic sp,#0xf' > arch/arm/crypto/speck-neon-core.S:423: Error: r13 not allowed here -- `bic sp,#0xf' > arch/arm/crypto/speck-neon-core.S:427: Error: r13 not allowed here -- `bic sp,#0xf' > arch/arm/crypto/speck-neon-core.S:431: Error: r13 not allowed here -- `bic sp,#0xf' > > The problem is that the 'bic' instruction can't operate on the 'sp' > register in Thumb2 mode. Fix it by using a temporary register. This > isn't in the main loop, so the performance difference is negligible. > This also matches what aes-neonbs-core.S does. > > Reported-by: Stefan Agner <stefan@agner.ch> > Fixes: ede9622162fa ("crypto: arm/speck - add NEON-accelerated implementation of Speck-XTS") > Signed-off-by: Eric Biggers <ebiggers@google.com> > --- > arch/arm/crypto/speck-neon-core.S | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/arch/arm/crypto/speck-neon-core.S b/arch/arm/crypto/speck-neon-core.S > index 3c1e203e53b9..57caa742016e 100644 > --- a/arch/arm/crypto/speck-neon-core.S > +++ b/arch/arm/crypto/speck-neon-core.S > @@ -272,9 +272,11 @@ > * Allocate stack space to store 128 bytes worth of tweaks. For > * performance, this space is aligned to a 16-byte boundary so that we > * can use the load/store instructions that declare 16-byte alignment. > + * For Thumb2 compatibility, don't do the 'bic' directly on 'sp'. > */ > - sub sp, #128 > - bic sp, #0xf > + sub r12, sp, #128 > + bic r12, #0xf > + mov sp, r12 > > .if \n == 64 > // Load first tweak Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
On 19.06.2018 00:33, Eric Biggers wrote: > Building the kernel with CONFIG_THUMB2_KERNEL=y and > CONFIG_CRYPTO_SPECK_NEON set fails with the following errors: > > arch/arm/crypto/speck-neon-core.S: Assembler messages: > > arch/arm/crypto/speck-neon-core.S:419: Error: r13 not allowed here > -- `bic sp,#0xf' > arch/arm/crypto/speck-neon-core.S:423: Error: r13 not allowed here > -- `bic sp,#0xf' > arch/arm/crypto/speck-neon-core.S:427: Error: r13 not allowed here > -- `bic sp,#0xf' > arch/arm/crypto/speck-neon-core.S:431: Error: r13 not allowed here > -- `bic sp,#0xf' > > The problem is that the 'bic' instruction can't operate on the 'sp' > register in Thumb2 mode. Fix it by using a temporary register. This > isn't in the main loop, so the performance difference is negligible. > This also matches what aes-neonbs-core.S does. > > Reported-by: Stefan Agner <stefan@agner.ch> > Fixes: ede9622162fa ("crypto: arm/speck - add NEON-accelerated > implementation of Speck-XTS") > Signed-off-by: Eric Biggers <ebiggers@google.com> > --- > arch/arm/crypto/speck-neon-core.S | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/arch/arm/crypto/speck-neon-core.S > b/arch/arm/crypto/speck-neon-core.S > index 3c1e203e53b9..57caa742016e 100644 > --- a/arch/arm/crypto/speck-neon-core.S > +++ b/arch/arm/crypto/speck-neon-core.S > @@ -272,9 +272,11 @@ > * Allocate stack space to store 128 bytes worth of tweaks. For > * performance, this space is aligned to a 16-byte boundary so that we > * can use the load/store instructions that declare 16-byte alignment. > + * For Thumb2 compatibility, don't do the 'bic' directly on 'sp'. > */ > - sub sp, #128 > - bic sp, #0xf > + sub r12, sp, #128 > + bic r12, #0xf > + mov sp, r12 Looks good to me and compiles fine here. Thanks! Reviewed-by: Stefan Agner <stefan@agner.ch> -- Stefan > > .if \n == 64 > // Load first tweak
On Mon, Jun 18, 2018 at 03:33:23PM -0700, Eric Biggers wrote: > Building the kernel with CONFIG_THUMB2_KERNEL=y and > CONFIG_CRYPTO_SPECK_NEON set fails with the following errors: > > arch/arm/crypto/speck-neon-core.S: Assembler messages: > > arch/arm/crypto/speck-neon-core.S:419: Error: r13 not allowed here -- `bic sp,#0xf' > arch/arm/crypto/speck-neon-core.S:423: Error: r13 not allowed here -- `bic sp,#0xf' > arch/arm/crypto/speck-neon-core.S:427: Error: r13 not allowed here -- `bic sp,#0xf' > arch/arm/crypto/speck-neon-core.S:431: Error: r13 not allowed here -- `bic sp,#0xf' > > The problem is that the 'bic' instruction can't operate on the 'sp' > register in Thumb2 mode. Fix it by using a temporary register. This > isn't in the main loop, so the performance difference is negligible. > This also matches what aes-neonbs-core.S does. > > Reported-by: Stefan Agner <stefan@agner.ch> > Fixes: ede9622162fa ("crypto: arm/speck - add NEON-accelerated implementation of Speck-XTS") > Signed-off-by: Eric Biggers <ebiggers@google.com> Patch applied. Thanks.
diff --git a/arch/arm/crypto/speck-neon-core.S b/arch/arm/crypto/speck-neon-core.S index 3c1e203e53b9..57caa742016e 100644 --- a/arch/arm/crypto/speck-neon-core.S +++ b/arch/arm/crypto/speck-neon-core.S @@ -272,9 +272,11 @@ * Allocate stack space to store 128 bytes worth of tweaks. For * performance, this space is aligned to a 16-byte boundary so that we * can use the load/store instructions that declare 16-byte alignment. + * For Thumb2 compatibility, don't do the 'bic' directly on 'sp'. */ - sub sp, #128 - bic sp, #0xf + sub r12, sp, #128 + bic r12, #0xf + mov sp, r12 .if \n == 64 // Load first tweak
Building the kernel with CONFIG_THUMB2_KERNEL=y and CONFIG_CRYPTO_SPECK_NEON set fails with the following errors: arch/arm/crypto/speck-neon-core.S: Assembler messages: arch/arm/crypto/speck-neon-core.S:419: Error: r13 not allowed here -- `bic sp,#0xf' arch/arm/crypto/speck-neon-core.S:423: Error: r13 not allowed here -- `bic sp,#0xf' arch/arm/crypto/speck-neon-core.S:427: Error: r13 not allowed here -- `bic sp,#0xf' arch/arm/crypto/speck-neon-core.S:431: Error: r13 not allowed here -- `bic sp,#0xf' The problem is that the 'bic' instruction can't operate on the 'sp' register in Thumb2 mode. Fix it by using a temporary register. This isn't in the main loop, so the performance difference is negligible. This also matches what aes-neonbs-core.S does. Reported-by: Stefan Agner <stefan@agner.ch> Fixes: ede9622162fa ("crypto: arm/speck - add NEON-accelerated implementation of Speck-XTS") Signed-off-by: Eric Biggers <ebiggers@google.com> --- arch/arm/crypto/speck-neon-core.S | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)