Only perform the NEON yield check for every 8 blocks of input, to
prevent taking a considerable performance hit on cores with very
fast crypto instructions and comparatively slow memory accesses,
such as the Cortex-A53.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
arch/arm64/crypto/aes-ce-ccm-core.S | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/arm64/crypto/aes-ce-ccm-core.S b/arch/arm64/crypto/aes-ce-ccm-core.S
index 88f5aef7934c..627710cdc220 100644
--- a/arch/arm64/crypto/aes-ce-ccm-core.S
+++ b/arch/arm64/crypto/aes-ce-ccm-core.S
@@ -208,6 +208,9 @@ CPU_LE( rev x26, x26 ) /* keep swabbed ctr in reg */
st1 {v1.16b}, [x19], #16 /* write output block */
beq 5f
+ tst w21, #(0x7 * 16) /* yield every 8 blocks */
+ b.ne 0b
+
if_will_cond_yield_neon
st1 {v0.16b}, [x24] /* store mac */
do_cond_yield_neon
--
2.11.0
