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authorHeiko Carstens <hca@linux.ibm.com>2024-09-19 15:40:04 +0300
committerVasily Gorbik <gor@linux.ibm.com>2024-09-23 18:57:04 +0300
commit8e391ae0607fc820e9ece87d1415e6a1ff274e69 (patch)
treecfb4dc4c017aa7c9999b4398d197b1895786adc0 /arch
parent1ec6d097897a35dfb55c4c31fc8633cf5be46497 (diff)
downloadlinux-8e391ae0607fc820e9ece87d1415e6a1ff274e69.tar.xz
s390/vdso: Get rid of permutation constants
The three byte masks for VECTOR PERMUTE are not needed, since the instruction VECTOR SHIFT LEFT DOUBLE BY BYTE can be used to implement the required "rotate left" easily. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/s390/kernel/vdso64/vgetrandom-chacha.S25
1 files changed, 10 insertions, 15 deletions
diff --git a/arch/s390/kernel/vdso64/vgetrandom-chacha.S b/arch/s390/kernel/vdso64/vgetrandom-chacha.S
index d802b0a96f41..475711e0c6a3 100644
--- a/arch/s390/kernel/vdso64/vgetrandom-chacha.S
+++ b/arch/s390/kernel/vdso64/vgetrandom-chacha.S
@@ -1,5 +1,6 @@
/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/stringify.h>
#include <linux/linkage.h>
#include <asm/alternative.h>
#include <asm/fpu-insn.h>
@@ -12,9 +13,6 @@
#define COPY1 %v5
#define COPY2 %v6
#define COPY3 %v7
-#define PERM4 %v16
-#define PERM8 %v17
-#define PERM12 %v18
#define BEPERM %v19
#define TMP0 %v20
#define TMP1 %v21
@@ -23,12 +21,9 @@
.section .rodata
- .balign 128
+ .balign 32
.Lconstants:
.long 0x61707865,0x3320646e,0x79622d32,0x6b206574 # endian-neutral
- .long 0x04050607,0x08090a0b,0x0c0d0e0f,0x00010203 # rotl 4 bytes
- .long 0x08090a0b,0x0c0d0e0f,0x00010203,0x04050607 # rotl 8 bytes
- .long 0x0c0d0e0f,0x00010203,0x04050607,0x08090a0b # rotl 12 bytes
.long 0x03020100,0x07060504,0x0b0a0908,0x0f0e0d0c # byte swap
.text
@@ -48,8 +43,8 @@ SYM_FUNC_START(__arch_chacha20_blocks_nostack)
/* COPY0 = "expand 32-byte k" */
VL COPY0,0,,%r1
- /* PERM4-PERM12,BEPERM = byte selectors for VPERM */
- VLM PERM4,BEPERM,16,%r1
+ /* BEPERM = byte selectors for VPERM */
+ ALTERNATIVE __stringify(VL BEPERM,16,,%r1), "brcl 0,0", ALT_FACILITY(148)
/* COPY1,COPY2 = key */
VLM COPY1,COPY2,0,%r3
@@ -89,11 +84,11 @@ SYM_FUNC_START(__arch_chacha20_blocks_nostack)
VERLLF STATE1,STATE1,7
/* STATE1[0,1,2,3] = STATE1[1,2,3,0] */
- VPERM STATE1,STATE1,STATE1,PERM4
+ VSLDB STATE1,STATE1,STATE1,4
/* STATE2[0,1,2,3] = STATE2[2,3,0,1] */
- VPERM STATE2,STATE2,STATE2,PERM8
+ VSLDB STATE2,STATE2,STATE2,8
/* STATE3[0,1,2,3] = STATE3[3,0,1,2] */
- VPERM STATE3,STATE3,STATE3,PERM12
+ VSLDB STATE3,STATE3,STATE3,12
/* STATE0 += STATE1, STATE3 = rotl32(STATE3 ^ STATE0, 16) */
VAF STATE0,STATE0,STATE1
@@ -116,11 +111,11 @@ SYM_FUNC_START(__arch_chacha20_blocks_nostack)
VERLLF STATE1,STATE1,7
/* STATE1[0,1,2,3] = STATE1[3,0,1,2] */
- VPERM STATE1,STATE1,STATE1,PERM12
+ VSLDB STATE1,STATE1,STATE1,12
/* STATE2[0,1,2,3] = STATE2[2,3,0,1] */
- VPERM STATE2,STATE2,STATE2,PERM8
+ VSLDB STATE2,STATE2,STATE2,8
/* STATE3[0,1,2,3] = STATE3[1,2,3,0] */
- VPERM STATE3,STATE3,STATE3,PERM4
+ VSLDB STATE3,STATE3,STATE3,4
brctg %r0,.Ldoubleround
/* OUTPUT0 = STATE0 + STATE0 */