On Thu, 18 Oct 2018 18:06:20 PDT (-0700), cota@braap.org wrote:
> Soon we will call cpu_has_work without the BQL.
>
> Cc: Michael Clark <mjc@sifive.com>
> Cc: Palmer Dabbelt <palmer@sifive.com>
> Cc: Sagar Karandikar <sagark@eecs.berkeley.edu>
> Cc: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
> Signed-off-by: Emilio G. Cota <cota@braap.org>
> ---
> target/riscv/cpu.c | 21 ++++++++++++++++++++-
> 1 file changed, 20 insertions(+), 1 deletion(-)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index d630e8fd6c..b10995c807 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -18,6 +18,7 @@
> */
>
> #include "qemu/osdep.h"
> +#include "qemu/main-loop.h"
> #include "qemu/log.h"
> #include "cpu.h"
> #include "exec/exec-all.h"
> @@ -244,11 +245,14 @@ static void riscv_cpu_synchronize_from_tb(CPUState *cs, TranslationBlock *tb)
> env->pc = tb->pc;
> }
>
> -static bool riscv_cpu_has_work(CPUState *cs)
> +static bool riscv_cpu_has_work_locked(CPUState *cs)
> {
> #ifndef CONFIG_USER_ONLY
> RISCVCPU *cpu = RISCV_CPU(cs);
> CPURISCVState *env = &cpu->env;
> +
> + g_assert(qemu_mutex_iothread_locked());
> +
> /*
> * Definition of the WFI instruction requires it to ignore the privilege
> * mode and delegation registers, but respect individual enables
> @@ -259,6 +263,21 @@ static bool riscv_cpu_has_work(CPUState *cs)
> #endif
> }
>
> +static bool riscv_cpu_has_work(CPUState *cs)
> +{
> + if (!qemu_mutex_iothread_locked()) {
> + bool ret;
> +
> + cpu_mutex_unlock(cs);
> + qemu_mutex_lock_iothread();
> + cpu_mutex_lock(cs);
> + ret = riscv_cpu_has_work_locked(cs);
> + qemu_mutex_unlock_iothread();
> + return ret;
> + }
> + return riscv_cpu_has_work_locked(cs);
> +}
> +
> void restore_state_to_opc(CPURISCVState *env, TranslationBlock *tb,
> target_ulong *data)
> {
I'm afraid I don't understand the locking scheme, but as far as the RISC-V
stuff goes this looks fine.
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Thanks!