Re: [PULL 1/2] target/hppa: Add CPU reset method

[Philippe Mathieu-Daudé]

Hi Helge,

On 30/12/24 01:22, deller@kernel.org wrote:
> From: Helge Deller <deller@gmx.de>
>
> Add the CPU reset method, which resets all CPU registers and the TLB to
> zero. Then the CPU will switch to 32-bit mode (PSW_W bit is not set) and
> start execution at address 0xf0000004.
> Although we currently want to zero out all values in the CPUHPPAState
> struct, add the end_reset_fields marker in case the state structs gets
> extended with other variables later on which should not be reset.

This patch is doing multiple things at once.

> Signed-off-by: Helge Deller <deller@gmx.de>
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   hw/hppa/machine.c |  6 +++---
>   target/hppa/cpu.c | 26 ++++++++++++++++++++++++--
>   target/hppa/cpu.h |  5 +++++
>   3 files changed, 32 insertions(+), 5 deletions(-)


> diff --git a/target/hppa/cpu.c b/target/hppa/cpu.c
> index c38439c180..cb1b5191a4 100644
> --- a/target/hppa/cpu.c
> +++ b/target/hppa/cpu.c
> @@ -194,11 +194,9 @@ static void hppa_cpu_realizefn(DeviceState *dev, Error 
> **errp)
>   
>   static void hppa_cpu_initfn(Object *obj)
>   {
> -    CPUState *cs = CPU(obj);
>       HPPACPU *cpu = HPPA_CPU(obj);
>       CPUHPPAState *env = &cpu->env;
>   
> -    cs->exception_index = -1;
>       cpu_hppa_loaded_fr0(env);
>       cpu_hppa_put_psw(env, PSW_W);

This is reset code.

Should PSW_M bit set on hard reset?

>   }
> @@ -235,15 +233,39 @@ static const TCGCPUOps hppa_tcg_ops = {
>   #endif /* !CONFIG_USER_ONLY */
>   };
>   
> +static void hppa_cpu_reset_hold(Object *obj, ResetType type)
> +{
> +    HPPACPU *cpu = HPPA_CPU(obj);
> +    HPPACPUClass *scc = HPPA_CPU_GET_CLASS(cpu);
> +    CPUHPPAState *env = &cpu->env;
> +    CPUState *cs = CPU(cpu);
> +
> +    if (scc->parent_phases.hold) {
> +        scc->parent_phases.hold(obj, type);
> +    }
> +
> +    memset(env, 0, offsetof(CPUHPPAState, end_reset_fields));
> +    cpu_set_pc(cs, 0xf0000004);
> +    cpu_hppa_put_psw(env, hppa_is_pa20(env) ? PSW_W : 0);

PSW_W is already cleared in cpu_hppa_put_psw() for PA1.x.

> +    cpu_hppa_loaded_fr0(env);
> +
> +    cs->exception_index = -1;
> +    cs->halted = 0;
> +}

For clarity I'll respin your patch including my comments.