Re: [PATCH 3/4] target/ppc: add TFMR SPR implementation with read and write helpers

[Cédric Le Goater]

On 6/4/23 01:36, Nicholas Piggin wrote:
> TFMR is the Time Facility Management Register which is specific to POWER
> CPUs, and used for the purpose of timebase management (generally by
> firmware, not the OS).
>
> This adds an initial simple TFMR register, which will form part of the
> core timebase facility model in the next patch.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>


Reviewed-by: Cédric Le Goater <clg@kaod.org>

Thanks,

C.


> ---
>   target/ppc/cpu_init.c        |  2 +-
>   target/ppc/helper.h          |  2 ++
>   target/ppc/spr_common.h      |  2 ++
>   target/ppc/timebase_helper.c | 13 +++++++++++++
>   target/ppc/translate.c       | 10 ++++++++++
>   5 files changed, 28 insertions(+), 1 deletion(-)
>
> diff --git a/target/ppc/cpu_init.c b/target/ppc/cpu_init.c
> index da0f7a7159..37088021d2 100644
> --- a/target/ppc/cpu_init.c
> +++ b/target/ppc/cpu_init.c
> @@ -5662,7 +5662,7 @@ static void register_power_common_book4_sprs(CPUPPCState 
> *env)
>       spr_register_hv(env, SPR_TFMR, "TFMR",
>                    SPR_NOACCESS, SPR_NOACCESS,
>                    SPR_NOACCESS, SPR_NOACCESS,
> -                 &spr_read_generic, &spr_write_generic,
> +                 &spr_read_tfmr, &spr_write_tfmr,
>                    0x00000000);
>       spr_register_hv(env, SPR_LDBAR, "LDBAR",
>                    SPR_NOACCESS, SPR_NOACCESS,
> diff --git a/target/ppc/helper.h b/target/ppc/helper.h
> index 16bb485c1a..166cacb3f9 100644
> --- a/target/ppc/helper.h
> +++ b/target/ppc/helper.h
> @@ -746,6 +746,8 @@ DEF_HELPER_2(store_40x_dbcr0, void, env, tl)
>   DEF_HELPER_2(store_40x_sler, void, env, tl)
>   DEF_HELPER_FLAGS_2(store_booke_tcr, TCG_CALL_NO_RWG, void, env, tl)
>   DEF_HELPER_FLAGS_2(store_booke_tsr, TCG_CALL_NO_RWG, void, env, tl)
> +DEF_HELPER_1(load_tfmr, tl, env)
> +DEF_HELPER_2(store_tfmr, void, env, tl)
>   DEF_HELPER_3(store_ibatl, void, env, i32, tl)
>   DEF_HELPER_3(store_ibatu, void, env, i32, tl)
>   DEF_HELPER_3(store_dbatl, void, env, i32, tl)
> diff --git a/target/ppc/spr_common.h b/target/ppc/spr_common.h
> index d6c679cd99..8ab17123a4 100644
> --- a/target/ppc/spr_common.h
> +++ b/target/ppc/spr_common.h
> @@ -196,6 +196,8 @@ void spr_write_ebb(DisasContext *ctx, int sprn, int gprn);
>   void spr_read_ebb_upper32(DisasContext *ctx, int gprn, int sprn);
>   void spr_write_ebb_upper32(DisasContext *ctx, int sprn, int gprn);
>   void spr_write_hmer(DisasContext *ctx, int sprn, int gprn);
> +void spr_read_tfmr(DisasContext *ctx, int gprn, int sprn);
> +void spr_write_tfmr(DisasContext *ctx, int sprn, int gprn);
>   void spr_write_lpcr(DisasContext *ctx, int sprn, int gprn);
>   void spr_read_dexcr_ureg(DisasContext *ctx, int gprn, int sprn);
>   #endif
> diff --git a/target/ppc/timebase_helper.c b/target/ppc/timebase_helper.c
> index de1ee85e0b..34b1d5ad05 100644
> --- a/target/ppc/timebase_helper.c
> +++ b/target/ppc/timebase_helper.c
> @@ -270,6 +270,19 @@ void helper_store_booke_tsr(CPUPPCState *env, target_ulong 
> val)
>       store_booke_tsr(env, val);
>   }
>   
> +#if defined(TARGET_PPC64)
> +/* POWER processor Timebase Facility */
> +target_ulong helper_load_tfmr(CPUPPCState *env)
> +{
> +    return env->spr[SPR_TFMR];
> +}
> +
> +void helper_store_tfmr(CPUPPCState *env, target_ulong val)
> +{
> +    env->spr[SPR_TFMR] = val;
> +}
> +#endif
> +
>   
> /*****************************************************************************/
>   /* Embedded PowerPC specific helpers */
>   
> diff --git a/target/ppc/translate.c b/target/ppc/translate.c
> index 8b312b46e0..9dcd66eac8 100644
> --- a/target/ppc/translate.c
> +++ b/target/ppc/translate.c
> @@ -1255,6 +1255,16 @@ void spr_write_hmer(DisasContext *ctx, int sprn, int 
> gprn)
>       spr_store_dump_spr(sprn);
>   }
>   
> +void spr_read_tfmr(DisasContext *ctx, int gprn, int sprn)
> +{
> +    gen_helper_load_tfmr(cpu_gpr[gprn], cpu_env);
> +}
> +
> +void spr_write_tfmr(DisasContext *ctx, int sprn, int gprn)
> +{
> +    gen_helper_store_tfmr(cpu_env, cpu_gpr[gprn]);
> +}
> +
>   void spr_write_lpcr(DisasContext *ctx, int sprn, int gprn)
>   {
>       gen_helper_store_lpcr(cpu_env, cpu_gpr[gprn]);