On Tue, 15 May 2018 15:51:20 PDT (-0700), bart.vanassche@xxxxxxx wrote:
The next patch in this series introduces a call to cmpxchg64()
in the block layer core for those architectures on which this
functionality is available. Make it possible to test whether
cmpxchg64() is available by introducing CONFIG_ARCH_HAVE_CMPXCHG64.
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Cc: "James E.J. Bottomley" <jejb@xxxxxxxxxxxxxxxx>
Cc: Helge Deller <deller@xxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Chris Zankel <chris@xxxxxxxxxx>
Cc: Max Filippov <jcmvbkbc@xxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
---
.../features/locking/cmpxchg64/arch-support.txt | 33 ++++++++++++++++++++++
arch/Kconfig | 3 ++
arch/alpha/Kconfig | 1 +
arch/arm/Kconfig | 1 +
arch/arm64/Kconfig | 1 +
arch/ia64/Kconfig | 1 +
arch/m68k/Kconfig | 1 +
arch/mips/Kconfig | 1 +
arch/parisc/Kconfig | 1 +
arch/powerpc/Kconfig | 1 +
arch/riscv/Kconfig | 1 +
arch/s390/Kconfig | 1 +
arch/sparc/Kconfig | 1 +
arch/x86/Kconfig | 1 +
arch/xtensa/Kconfig | 1 +
15 files changed, 49 insertions(+)
create mode 100644 Documentation/features/locking/cmpxchg64/arch-support.txt
[...]
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -8,6 +8,7 @@ config RISCV
select OF
select OF_EARLY_FLATTREE
select OF_IRQ
+ select ARCH_HAVE_CMPXCHG64
select ARCH_WANT_FRAME_POINTERS
select CLONE_BACKWARDS
select COMMON_CLK
If I understand correctly, we should only have ARCH_HAVE_CMPXCHG64 on 64-bit
RISC-V systems so this should look something like
select ARCH_HAVE_CMPXCHG64 if 64BIT
Of course, the RV32I port is broken right now so it's not a big deal, but we're
working through making it less broken...
