[PATCH 1/5] crypto/arm64: aes-ce-ccm - Avoid pointless yield of the NEON unit

Ard Biesheuvel posted 5 patches 2 weeks ago
There is a newer version of this series
[PATCH 1/5] crypto/arm64: aes-ce-ccm - Avoid pointless yield of the NEON unit
Posted by Ard Biesheuvel 2 weeks ago
From: Ard Biesheuvel <ardb@kernel.org>

Kernel mode NEON sections are now preemptible on arm64, and so there is
no need to yield it explicitly in order to prevent scheduling latency
spikes.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 arch/arm64/crypto/aes-ce-ccm-glue.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/arch/arm64/crypto/aes-ce-ccm-glue.c b/arch/arm64/crypto/aes-ce-ccm-glue.c
index 2d791d51891b..2eb4e76cabc3 100644
--- a/arch/arm64/crypto/aes-ce-ccm-glue.c
+++ b/arch/arm64/crypto/aes-ce-ccm-glue.c
@@ -114,11 +114,8 @@ static u32 ce_aes_ccm_auth_data(u8 mac[], u8 const in[], u32 abytes,
 			in += adv;
 			abytes -= adv;
 
-			if (unlikely(rem)) {
-				kernel_neon_end();
-				kernel_neon_begin();
+			if (unlikely(rem))
 				macp = 0;
-			}
 		} else {
 			u32 l = min(AES_BLOCK_SIZE - macp, abytes);
 
-- 
2.51.0.384.g4c02a37b29-goog
Re: [PATCH 1/5] crypto/arm64: aes-ce-ccm - Avoid pointless yield of the NEON unit
Posted by Mark Brown 1 week, 5 days ago
On Thu, Sep 18, 2025 at 08:35:41AM +0200, Ard Biesheuvel wrote:
> From: Ard Biesheuvel <ardb@kernel.org>
> 
> Kernel mode NEON sections are now preemptible on arm64, and so there is
> no need to yield it explicitly in order to prevent scheduling latency
> spikes.
> 
> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

Reviewed-by: Mark Brown <broonie@kernel.org>