在 2021/8/29 20:49, Xi Ruoyao 写道:
Newest Loongson-3 processors have moved to use LoongArch architecture.
Sadly, the LL/SC issue is still existing on both latest Loongson-3
processors using MIPS64 (Loongson-3A4000) and LoongArch
(Loongson-3A5000).
LLSC is fixed on Loongson-3A4000 as per CPUCFG report.
As it's very unlikely there will be new Loongson-3 processors using
MIPS64, let's stop people from false hoping.
Signed-off-by: Xi Ruoyao <xry111@xxxxxxxxxxxxxxxx>
Cc: Huacai Chen <chenhuacai@xxxxxxxxxx>
---
Huacai: how's the status of LL/SC issue on Loongson-2K? If
the issue exists on it as well, we can just force
CPU_LOONGSON3_WORKAROUNDS when CONFIG_CPU_LOONGSON64 and
CONFIG_SMP are both selected.
Loongson-2K do need LLSC workaround, although the reason behind the
workaround seems different...
Thanks.
- Jiaxun
arch/mips/Kconfig | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 6dfb27d531dd..ff5f344a371e 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1433,19 +1433,14 @@ config LOONGSON3_ENHANCEMENT
new Loongson-3 machines only, please say 'Y' here.
config CPU_LOONGSON3_WORKAROUNDS
- bool "Old Loongson-3 LLSC Workarounds"
+ bool "Loongson-3 LLSC Workarounds"
default y if SMP
depends on CPU_LOONGSON64
help
Loongson-3 processors have the llsc issues which require workarounds.
Without workarounds the system may hang unexpectedly.
- Newer Loongson-3 will fix these issues and no workarounds are needed.
- The workarounds have no significant side effect on them but may
- decrease the performance of the system so this option should be
- disabled unless the kernel is intended to be run on old systems.
-
- If unsure, please say Y.
+ Say Y, unless you know what you are doing.
config CPU_LOONGSON3_CPUCFG_EMULATION
bool "Emulate the CPUCFG instruction on older Loongson cores"
