diff options
| author | Will Deacon <will.deacon@arm.com> | 2016-09-06 16:40:23 +0100 |
|---|---|---|
| committer | Sami Tolvanen <samitolvanen@google.com> | 2017-01-04 09:02:08 -0800 |
| commit | 12ac5b67a13dabdb6e9cd9c0811bcebe12a23b1c (patch) | |
| tree | 696a605dd5b6fed0196104d1eb3cfe40366a479f | |
| parent | c86266edfaa4e39a5f784e1c9ee8ec6ba2803cc1 (diff) | |
UPSTREAM: arm64: barriers: introduce nops and __nops macros for NOP sequences
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>
Bug: 31432001
Change-Id: I7f82b677a065ede302a763d39ffcc3fef83f8fbe
(cherry picked from commit f99a250cb6a3b301b101b4c0f5fcb80593bba6dc)
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
| -rw-r--r-- | arch/arm64/include/asm/assembler.h | 9 | ||||
| -rw-r--r-- | arch/arm64/include/asm/barrier.h | 3 |
2 files changed, 12 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index 9e8ac1e73457..bacc75b6c78c 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -99,6 +99,15 @@ .endm /* + * NOP sequence + */ + .macro nops, num + .rept \num + nop + .endr + .endm + +/* * Emit an entry into the exception table */ .macro _asm_extable, from, to diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h index 9622eb48f894..c5dbc5cb8f10 100644 --- a/arch/arm64/include/asm/barrier.h +++ b/arch/arm64/include/asm/barrier.h @@ -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") |