Nicholas Piggin <npiggin@xxxxxxxxx> writes: > This register controls supervisor SPR modifications, and as such is only > relevant for KVM. KVM always sets AMOR to ~0 on guest entry, and never > restores it coming back out to the host, so it can be kept constant and > avoid the mtSPR in KVM guest entry. > > -21 cycles (9116) cycles POWER9 virt-mode NULL hcall > > Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx> Reviewed-by: Fabiano Rosas <farosas@xxxxxxxxxxxxx> > --- > arch/powerpc/kernel/cpu_setup_power.c | 8 ++++++++ > arch/powerpc/kernel/dt_cpu_ftrs.c | 2 ++ > arch/powerpc/kvm/book3s_hv_p9_entry.c | 2 -- > arch/powerpc/kvm/book3s_hv_rmhandlers.S | 2 -- > arch/powerpc/mm/book3s64/radix_pgtable.c | 15 --------------- > arch/powerpc/platforms/powernv/idle.c | 8 +++----- > 6 files changed, 13 insertions(+), 24 deletions(-) > > diff --git a/arch/powerpc/kernel/cpu_setup_power.c b/arch/powerpc/kernel/cpu_setup_power.c > index 3cca88ee96d7..a29dc8326622 100644 > --- a/arch/powerpc/kernel/cpu_setup_power.c > +++ b/arch/powerpc/kernel/cpu_setup_power.c > @@ -137,6 +137,7 @@ void __setup_cpu_power7(unsigned long offset, struct cpu_spec *t) > return; > > mtspr(SPRN_LPID, 0); > + mtspr(SPRN_AMOR, ~0); > mtspr(SPRN_PCR, PCR_MASK); > init_LPCR_ISA206(mfspr(SPRN_LPCR), LPCR_LPES1 >> LPCR_LPES_SH); > } > @@ -150,6 +151,7 @@ void __restore_cpu_power7(void) > return; > > mtspr(SPRN_LPID, 0); > + mtspr(SPRN_AMOR, ~0); > mtspr(SPRN_PCR, PCR_MASK); > init_LPCR_ISA206(mfspr(SPRN_LPCR), LPCR_LPES1 >> LPCR_LPES_SH); > } > @@ -164,6 +166,7 @@ void __setup_cpu_power8(unsigned long offset, struct cpu_spec *t) > return; > > mtspr(SPRN_LPID, 0); > + mtspr(SPRN_AMOR, ~0); > mtspr(SPRN_PCR, PCR_MASK); > init_LPCR_ISA206(mfspr(SPRN_LPCR) | LPCR_PECEDH, 0); /* LPES = 0 */ > init_HFSCR(); > @@ -184,6 +187,7 @@ void __restore_cpu_power8(void) > return; > > mtspr(SPRN_LPID, 0); > + mtspr(SPRN_AMOR, ~0); > mtspr(SPRN_PCR, PCR_MASK); > init_LPCR_ISA206(mfspr(SPRN_LPCR) | LPCR_PECEDH, 0); /* LPES = 0 */ > init_HFSCR(); > @@ -202,6 +206,7 @@ void __setup_cpu_power9(unsigned long offset, struct cpu_spec *t) > mtspr(SPRN_PSSCR, 0); > mtspr(SPRN_LPID, 0); > mtspr(SPRN_PID, 0); > + mtspr(SPRN_AMOR, ~0); > mtspr(SPRN_PCR, PCR_MASK); > init_LPCR_ISA300((mfspr(SPRN_LPCR) | LPCR_PECEDH | LPCR_PECE_HVEE |\ > LPCR_HVICE | LPCR_HEIC) & ~(LPCR_UPRT | LPCR_HR), 0); > @@ -223,6 +228,7 @@ void __restore_cpu_power9(void) > mtspr(SPRN_PSSCR, 0); > mtspr(SPRN_LPID, 0); > mtspr(SPRN_PID, 0); > + mtspr(SPRN_AMOR, ~0); > mtspr(SPRN_PCR, PCR_MASK); > init_LPCR_ISA300((mfspr(SPRN_LPCR) | LPCR_PECEDH | LPCR_PECE_HVEE |\ > LPCR_HVICE | LPCR_HEIC) & ~(LPCR_UPRT | LPCR_HR), 0); > @@ -242,6 +248,7 @@ void __setup_cpu_power10(unsigned long offset, struct cpu_spec *t) > mtspr(SPRN_PSSCR, 0); > mtspr(SPRN_LPID, 0); > mtspr(SPRN_PID, 0); > + mtspr(SPRN_AMOR, ~0); > mtspr(SPRN_PCR, PCR_MASK); > init_LPCR_ISA300((mfspr(SPRN_LPCR) | LPCR_PECEDH | LPCR_PECE_HVEE |\ > LPCR_HVICE | LPCR_HEIC) & ~(LPCR_UPRT | LPCR_HR), 0); > @@ -264,6 +271,7 @@ void __restore_cpu_power10(void) > mtspr(SPRN_PSSCR, 0); > mtspr(SPRN_LPID, 0); > mtspr(SPRN_PID, 0); > + mtspr(SPRN_AMOR, ~0); > mtspr(SPRN_PCR, PCR_MASK); > init_LPCR_ISA300((mfspr(SPRN_LPCR) | LPCR_PECEDH | LPCR_PECE_HVEE |\ > LPCR_HVICE | LPCR_HEIC) & ~(LPCR_UPRT | LPCR_HR), 0); > diff --git a/arch/powerpc/kernel/dt_cpu_ftrs.c b/arch/powerpc/kernel/dt_cpu_ftrs.c > index 358aee7c2d79..0a6b36b4bda8 100644 > --- a/arch/powerpc/kernel/dt_cpu_ftrs.c > +++ b/arch/powerpc/kernel/dt_cpu_ftrs.c > @@ -80,6 +80,7 @@ static void __restore_cpu_cpufeatures(void) > mtspr(SPRN_LPCR, system_registers.lpcr); > if (hv_mode) { > mtspr(SPRN_LPID, 0); > + mtspr(SPRN_AMOR, ~0); > mtspr(SPRN_HFSCR, system_registers.hfscr); > mtspr(SPRN_PCR, system_registers.pcr); > } > @@ -216,6 +217,7 @@ static int __init feat_enable_hv(struct dt_cpu_feature *f) > } > > mtspr(SPRN_LPID, 0); > + mtspr(SPRN_AMOR, ~0); > > lpcr = mfspr(SPRN_LPCR); > lpcr &= ~LPCR_LPES0; /* HV external interrupts */ > diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c > index c4f3e066fcb4..a3281f0c9214 100644 > --- a/arch/powerpc/kvm/book3s_hv_p9_entry.c > +++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c > @@ -286,8 +286,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc > mtspr(SPRN_SPRG2, vcpu->arch.shregs.sprg2); > mtspr(SPRN_SPRG3, vcpu->arch.shregs.sprg3); > > - mtspr(SPRN_AMOR, ~0UL); > - > local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_HV_P9; > > /* > diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S > index 8dd437d7a2c6..007f87b97184 100644 > --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S > +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S > @@ -772,10 +772,8 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S) > /* Restore AMR and UAMOR, set AMOR to all 1s */ > ld r5,VCPU_AMR(r4) > ld r6,VCPU_UAMOR(r4) > - li r7,-1 > mtspr SPRN_AMR,r5 > mtspr SPRN_UAMOR,r6 > - mtspr SPRN_AMOR,r7 > > /* Restore state of CTRL run bit; assume 1 on entry */ > lwz r5,VCPU_CTRL(r4) > diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c > index fe236c38ce00..b985cfead5d7 100644 > --- a/arch/powerpc/mm/book3s64/radix_pgtable.c > +++ b/arch/powerpc/mm/book3s64/radix_pgtable.c > @@ -566,18 +566,6 @@ void __init radix__early_init_devtree(void) > return; > } > > -static void radix_init_amor(void) > -{ > - /* > - * In HV mode, we init AMOR (Authority Mask Override Register) so that > - * the hypervisor and guest can setup IAMR (Instruction Authority Mask > - * Register), enable key 0 and set it to 1. > - * > - * AMOR = 0b1100 .... 0000 (Mask for key 0 is 11) > - */ > - mtspr(SPRN_AMOR, (3ul << 62)); > -} > - > void __init radix__early_init_mmu(void) > { > unsigned long lpcr; > @@ -638,7 +626,6 @@ void __init radix__early_init_mmu(void) > lpcr = mfspr(SPRN_LPCR); > mtspr(SPRN_LPCR, lpcr | LPCR_UPRT | LPCR_HR); > radix_init_partition_table(); > - radix_init_amor(); > } else { > radix_init_pseries(); > } > @@ -662,8 +649,6 @@ void radix__early_init_mmu_secondary(void) > > set_ptcr_when_no_uv(__pa(partition_tb) | > (PATB_SIZE_SHIFT - 12)); > - > - radix_init_amor(); > } > > radix__switch_mmu_context(NULL, &init_mm); > diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c > index 180baecad914..f791ca041854 100644 > --- a/arch/powerpc/platforms/powernv/idle.c > +++ b/arch/powerpc/platforms/powernv/idle.c > @@ -306,8 +306,8 @@ struct p7_sprs { > /* per thread SPRs that get lost in shallow states */ > u64 amr; > u64 iamr; > - u64 amor; > u64 uamor; > + /* amor is restored to constant ~0 */ > }; > > static unsigned long power7_idle_insn(unsigned long type) > @@ -378,7 +378,6 @@ static unsigned long power7_idle_insn(unsigned long type) > if (cpu_has_feature(CPU_FTR_ARCH_207S)) { > sprs.amr = mfspr(SPRN_AMR); > sprs.iamr = mfspr(SPRN_IAMR); > - sprs.amor = mfspr(SPRN_AMOR); > sprs.uamor = mfspr(SPRN_UAMOR); > } > > @@ -397,7 +396,7 @@ static unsigned long power7_idle_insn(unsigned long type) > */ > mtspr(SPRN_AMR, sprs.amr); > mtspr(SPRN_IAMR, sprs.iamr); > - mtspr(SPRN_AMOR, sprs.amor); > + mtspr(SPRN_AMOR, ~0); > mtspr(SPRN_UAMOR, sprs.uamor); > } > } > @@ -687,7 +686,6 @@ static unsigned long power9_idle_stop(unsigned long psscr) > > sprs.amr = mfspr(SPRN_AMR); > sprs.iamr = mfspr(SPRN_IAMR); > - sprs.amor = mfspr(SPRN_AMOR); > sprs.uamor = mfspr(SPRN_UAMOR); > > srr1 = isa300_idle_stop_mayloss(psscr); /* go idle */ > @@ -708,7 +706,7 @@ static unsigned long power9_idle_stop(unsigned long psscr) > */ > mtspr(SPRN_AMR, sprs.amr); > mtspr(SPRN_IAMR, sprs.iamr); > - mtspr(SPRN_AMOR, sprs.amor); > + mtspr(SPRN_AMOR, ~0); > mtspr(SPRN_UAMOR, sprs.uamor); > > /*