On 2017-07-06 16:20, Richard Henderson wrote: > As for other targets, cmpxchg isn't quite right for ll/sc, > suffering from an ABA race, but is sufficient to implement > portable atomic operations. > > Signed-off-by: Richard Henderson <r...@twiddle.net> > --- > target/sh4/cpu.h | 3 ++- > target/sh4/translate.c | 56 > +++++++++++++++++++++++++++++++++----------------- > 2 files changed, 39 insertions(+), 20 deletions(-)
For the linux-user case, where we need to emulate sequences that needs to be executed on multiple CPUs, while the ISA has been designed for a single CPU, this patch looks good. There is no real other way to do it. For the system case, one might imagine using MOVLI/MOVCO with a different address, although 1) it hasn't been designed for that 2) all the sequences I have found use the same address. I therefore wonder if we should just add the code to correctly clear LDST in case of interrupt or exception. -- Aurelien Jarno GPG: 4096R/1DDD8C9B aurel...@aurel32.net http://www.aurel32.net
