system/linux
system/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux synced 2024-10-08 12:22:38 +00:00
Code Issues Packages Projects Releases Wiki Activity

arm64: barriers: introduce nops and __nops macros for NOP sequences

Browse source 
NOP sequences tend to get used for padding out alternative sections
and uarch-specific pipeline flushes in errata workarounds.

This patch adds macros for generating these sequences as both inline
asm blocks, but also as strings suitable for embedding in other asm
blocks directly.

Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Will Deacon 2016-09-06 16:40:23 +01:00
parent 8a71f0c656
commit f99a250cb6
2 changed files with 12 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

9
arch/arm64/include/asm/assembler.h
View file

@ -86,6 +86,15 @@
dmb \opt
.endm
/*
* NOP sequence
*/
.macro nops, num
.rept \num
nop
.endr
.endm
/*
* Emit an entry into the exception table
*/

3
arch/arm64/include/asm/barrier.h
View file

@ -20,6 +20,9 @@
#ifndef __ASSEMBLY__
#define __nops(n) ".rept " #n "\nnop\n.endr\n"
#define nops(n) asm volatile(__nops(n))
#define sev() asm volatile("sev" : : : "memory")
#define wfe() asm volatile("wfe" : : : "memory")
#define wfi() asm volatile("wfi" : : : "memory")