crypto: aesni - Add fast path for > 16 byte update

We can fast-path any < 16 byte read if the full message is > 16 bytes,
and shift over by the appropriate amount.  Usually we are
reading > 16 bytes, so this should be faster than the READ_PARTIAL
macro introduced in b20209c91e2 for the average case.

Signed-off-by: Dave Watson <davejwatson@fb.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/arch/x86/crypto/aesni-intel_asm.S b/arch/x86/crypto/aesni-intel_asm.S
index 760a517..c00f32c 100644 (file)
--- a/arch/x86/crypto/aesni-intel_asm.S
+++ b/arch/x86/crypto/aesni-intel_asm.S
@@ -356,12 +356,37 @@ _zero_cipher_left_\@:
        ENCRYPT_SINGLE_BLOCK    %xmm0, %xmm1        # Encrypt(K, Yn)
        movdqu %xmm0, PBlockEncKey(%arg2)
 
+       cmp     $16, %arg5
+       jge _large_enough_update_\@
+
        lea (%arg4,%r11,1), %r10
        mov %r13, %r12
        READ_PARTIAL_BLOCK %r10 %r12 %xmm2 %xmm1
+       jmp _data_read_\@
+
+_large_enough_update_\@:
+       sub     $16, %r11
+       add     %r13, %r11
+
+       # receive the last <16 Byte block
+       movdqu  (%arg4, %r11, 1), %xmm1
 
+       sub     %r13, %r11
+       add     $16, %r11
+
+       lea     SHIFT_MASK+16(%rip), %r12
+       # adjust the shuffle mask pointer to be able to shift 16-r13 bytes
+       # (r13 is the number of bytes in plaintext mod 16)
+       sub     %r13, %r12
+       # get the appropriate shuffle mask
+       movdqu  (%r12), %xmm2
+       # shift right 16-r13 bytes
+       PSHUFB_XMM  %xmm2, %xmm1
+
+_data_read_\@:
        lea ALL_F+16(%rip), %r12
        sub %r13, %r12
+
 .ifc \operation, dec
        movdqa  %xmm1, %xmm2
 .endif