From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3tKbcy3ZJMzDvvd for ; Fri, 18 Nov 2016 09:38:26 +1100 (AEDT) Message-ID: <1479422306.6542.32.camel@neuling.org> Subject: Re: [PATCH] powerpc/64: Fix setting of AIL in hypervisor mode From: Michael Neuling To: Benjamin Herrenschmidt , linuxppc-dev@lists.ozlabs.org Cc: Anton Blanchard Date: Fri, 18 Nov 2016 09:38:26 +1100 In-Reply-To: <1479184113.2608.45.camel@kernel.crashing.org> References: <1479184113.2608.45.camel@kernel.crashing.org> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, 2016-11-15 at 15:28 +1100, Benjamin Herrenschmidt wrote: > Commit d3cbff1b5 "powerpc: Put exception configuration in a common place" > broke the setting of the AIL bit (which enables taking exceptions with > the MMU still on) on all processors, moving it incorrectly to a function > called only on the boot CPU. This was correct for the guest case but > not when running in hypervisor mode. >=20 > This fixes it by partially reverting that commit, putting the setting > back in cpu_ready_for_interrupts() >=20 > Signed-off-by: Benjamin Herrenschmidt > Fixes: d3cbff1b5 ("powerpc: Put exception configuration in a common place= ") > CC: stable@vger.kernel.org # v4.8+ Acked-By: Michael Neuling > --- > =C2=A0arch/powerpc/kernel/setup_64.c | 20 ++++++++++++++------ > =C2=A01 file changed, 14 insertions(+), 6 deletions(-) >=20 > diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_6= 4.c > index 7ac8e6e..ac75224 100644 > --- a/arch/powerpc/kernel/setup_64.c > +++ b/arch/powerpc/kernel/setup_64.c > @@ -226,17 +226,25 @@ static void __init configure_exceptions(void) > =C2=A0 if (firmware_has_feature(FW_FEATURE_OPAL)) > =C2=A0 opal_configure_cores(); > =C2=A0 > - /* Enable AIL if supported, and we are in hypervisor mode */ > - if (early_cpu_has_feature(CPU_FTR_HVMODE) && > - =C2=A0=C2=A0=C2=A0=C2=A0early_cpu_has_feature(CPU_FTR_ARCH_207S)) { > - unsigned long lpcr =3D mfspr(SPRN_LPCR); > - mtspr(SPRN_LPCR, lpcr | LPCR_AIL_3); > - } > + /* AIL on native is done in cpu_ready_for_interrupts */ > =C2=A0 } > =C2=A0} > =C2=A0 > =C2=A0static void cpu_ready_for_interrupts(void) > =C2=A0{ > + /* > + =C2=A0* Enable AIL if supported, and we are in hypervisor mode. This > + =C2=A0* is called once for every processor. > + =C2=A0* > + =C2=A0* If we are not in hypervisor mode the job is done once for > + =C2=A0* the whole partition in configure_exceptions(). > + =C2=A0*/ > + if (early_cpu_has_feature(CPU_FTR_HVMODE) && > + =C2=A0=C2=A0=C2=A0=C2=A0early_cpu_has_feature(CPU_FTR_ARCH_207S)) { > + unsigned long lpcr =3D mfspr(SPRN_LPCR); > + mtspr(SPRN_LPCR, lpcr | LPCR_AIL_3); > + } > + > =C2=A0 /* Set IR and DR in PACA MSR */ > =C2=A0 get_paca()->kernel_msr =3D MSR_KERNEL; > =C2=A0} >=20