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Date:   Mon, 20 Jul 2020 09:57:41 +1000
From:   Nicholas Piggin <npiggin@gmail.com>
Subject: Re: [PATCH v3 2/3] powerpc/powernv/idle: Rename
 pnv_first_spr_loss_level variable
To:     benh@kernel.crashing.org, ego@linux.vnet.ibm.com,
        linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
        mikey@neuling.org, mpe@ellerman.id.au, paulus@samba.org,
        pratik.r.sampat@gmail.com,
        Pratik Rajesh Sampat <psampat@linux.ibm.com>,
        svaidy@linux.ibm.com
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        <20200717185306.60607-3-psampat@linux.ibm.com>
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Excerpts from Pratik Rajesh Sampat's message of July 18, 2020 4:53 am:
> Replace the variable name from using "pnv_first_spr_loss_level" to
> "pnv_first_fullstate_loss_level".
>=20
> As pnv_first_spr_loss_level is supposed to be the earliest state that
> has OPAL_PM_LOSE_FULL_CONTEXT set, however as shallow states too loose
> SPR values, render an incorrect terminology.

It also doesn't lose "full" state at this loss level though. From the=20
architecture it could be called "hv state loss level", but in POWER10=20
even that is not strictly true.


>=20
> Signed-off-by: Pratik Rajesh Sampat <psampat@linux.ibm.com>
> ---
>  arch/powerpc/platforms/powernv/idle.c | 18 +++++++++---------
>  1 file changed, 9 insertions(+), 9 deletions(-)
>=20
> diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platfor=
ms/powernv/idle.c
> index f62904f70fc6..d439e11af101 100644
> --- a/arch/powerpc/platforms/powernv/idle.c
> +++ b/arch/powerpc/platforms/powernv/idle.c
> @@ -48,7 +48,7 @@ static bool default_stop_found;
>   * First stop state levels when SPR and TB loss can occur.
>   */
>  static u64 pnv_first_tb_loss_level =3D MAX_STOP_STATE + 1;
> -static u64 pnv_first_spr_loss_level =3D MAX_STOP_STATE + 1;
> +static u64 pnv_first_fullstate_loss_level =3D MAX_STOP_STATE + 1;
> =20
>  /*
>   * psscr value and mask of the deepest stop idle state.
> @@ -657,7 +657,7 @@ static unsigned long power9_idle_stop(unsigned long p=
sscr, bool mmu_on)
>  		  */
>  		mmcr0		=3D mfspr(SPRN_MMCR0);
>  	}
> -	if ((psscr & PSSCR_RL_MASK) >=3D pnv_first_spr_loss_level) {
> +	if ((psscr & PSSCR_RL_MASK) >=3D pnv_first_fullstate_loss_level) {
>  		sprs.lpcr	=3D mfspr(SPRN_LPCR);
>  		sprs.hfscr	=3D mfspr(SPRN_HFSCR);
>  		sprs.fscr	=3D mfspr(SPRN_FSCR);
> @@ -741,7 +741,7 @@ static unsigned long power9_idle_stop(unsigned long p=
sscr, bool mmu_on)
>  	 * just always test PSSCR for SPR/TB state loss.
>  	 */
>  	pls =3D (psscr & PSSCR_PLS) >> PSSCR_PLS_SHIFT;
> -	if (likely(pls < pnv_first_spr_loss_level)) {
> +	if (likely(pls < pnv_first_fullstate_loss_level)) {
>  		if (sprs_saved)
>  			atomic_stop_thread_idle();
>  		goto out;
> @@ -1088,7 +1088,7 @@ static void __init pnv_power9_idle_init(void)
>  	 * the deepest loss-less (OPAL_PM_STOP_INST_FAST) stop state.
>  	 */
>  	pnv_first_tb_loss_level =3D MAX_STOP_STATE + 1;
> -	pnv_first_spr_loss_level =3D MAX_STOP_STATE + 1;
> +	pnv_first_fullstate_loss_level =3D MAX_STOP_STATE + 1;
>  	for (i =3D 0; i < nr_pnv_idle_states; i++) {
>  		int err;
>  		struct pnv_idle_states_t *state =3D &pnv_idle_states[i];
> @@ -1099,8 +1099,8 @@ static void __init pnv_power9_idle_init(void)
>  			pnv_first_tb_loss_level =3D psscr_rl;
> =20
>  		if ((state->flags & OPAL_PM_LOSE_FULL_CONTEXT) &&
> -		     (pnv_first_spr_loss_level > psscr_rl))
> -			pnv_first_spr_loss_level =3D psscr_rl;
> +		     (pnv_first_fullstate_loss_level > psscr_rl))
> +			pnv_first_fullstate_loss_level =3D psscr_rl;
> =20
>  		/*
>  		 * The idle code does not deal with TB loss occurring
> @@ -1111,8 +1111,8 @@ static void __init pnv_power9_idle_init(void)
>  		 * compatibility.
>  		 */
>  		if ((state->flags & OPAL_PM_TIMEBASE_STOP) &&
> -		     (pnv_first_spr_loss_level > psscr_rl))
> -			pnv_first_spr_loss_level =3D psscr_rl;
> +		     (pnv_first_fullstate_loss_level > psscr_rl))
> +			pnv_first_fullstate_loss_level =3D psscr_rl;
> =20
>  		err =3D validate_psscr_val_mask(&state->psscr_val,
>  					      &state->psscr_mask,
> @@ -1158,7 +1158,7 @@ static void __init pnv_power9_idle_init(void)
>  	}
> =20
>  	pr_info("cpuidle-powernv: First stop level that may lose SPRs =3D 0x%ll=
x\n",
> -		pnv_first_spr_loss_level);
> +		pnv_first_fullstate_loss_level);
> =20
>  	pr_info("cpuidle-powernv: First stop level that may lose timebase =3D 0=
x%llx\n",
>  		pnv_first_tb_loss_level);
> --=20
> 2.25.4
>=20
>=20