On Tue, May 12, 2020 at 07:43:26AM +0530, Anshuman Khandual wrote: > This replaces multiple open encoding (0x7) with ID_AA64MMFR0_PARANGE_MASK > thus cleaning the clutter. It modifies an existing ID_AA64MMFR0 helper and > introduces a new one i.e id_aa64mmfr0_iparange() and id_aa64mmfr0_parange() > respectively. > > Cc: Catalin Marinas <catalin.marinas@xxxxxxx> > Cc: Will Deacon <will@xxxxxxxxxx> > Cc: Marc Zyngier <maz@xxxxxxxxxx> > Cc: James Morse <james.morse@xxxxxxx> > Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx > Cc: kvmarm@xxxxxxxxxxxxxxxxxxxxx > > Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx> > --- > This applies after (https://patchwork.kernel.org/patch/11541893/). > > arch/arm64/include/asm/cpufeature.h | 11 ++++++++++- > arch/arm64/kernel/cpufeature.c | 5 ++--- > arch/arm64/kvm/reset.c | 9 +++++---- > 3 files changed, 17 insertions(+), 8 deletions(-) > > diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h > index 1291ad5a9ccb..320cfc5b6025 100644 > --- a/arch/arm64/include/asm/cpufeature.h > +++ b/arch/arm64/include/asm/cpufeature.h > @@ -706,8 +706,17 @@ void arm64_set_ssbd_mitigation(bool state); > > extern int do_emulate_mrs(struct pt_regs *regs, u32 sys_reg, u32 rt); > > -static inline u32 id_aa64mmfr0_parange_to_phys_shift(int parange) > +#define ID_AA64MMFR0_PARANGE_MASK 0x7 We already have ID_AA64MMFR0_PARANGE_SHIFT in <asm/sysreg.h>, so if we need this it should live there too. The ARM ARM tells me ID_AA64MMFR0_EL1.PARange is bits 3:0, so this should be 0xf. Given it's a standard 4-bit field, do we even need this? We have helpers that assume 4 bits for standard fields, e.g. cpuid_feature_extract_unsigned_field(). > + > +static inline u32 id_aa64mmfr0_parange(u64 mmfr0) > { > + return mmfr0 & ID_AA64MMFR0_PARANGE_MASK; > +} return cpuid_feature_extract_unsigned_field(mmfr0, ID_AA64MMFR0_PARANGE_SHIFT); > + > +static inline u32 id_aa64mmfr0_iparange(u64 mmfr0) > +{ > + int parange = id_aa64mmfr0_parange(mmfr0); > + > switch (parange) { > case 0: return 32; > case 1: return 36; > diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c > index 30917fe7942a..2c62f7c64a3c 100644 > --- a/arch/arm64/kernel/cpufeature.c > +++ b/arch/arm64/kernel/cpufeature.c > @@ -2185,7 +2185,7 @@ static void verify_sve_features(void) > void verify_hyp_capabilities(void) > { > u64 safe_mmfr1, mmfr0, mmfr1; > - int parange, ipa_max; > + int ipa_max; > unsigned int safe_vmid_bits, vmid_bits; > > safe_mmfr1 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1); > @@ -2201,8 +2201,7 @@ void verify_hyp_capabilities(void) > } > > /* Verify IPA range */ > - parange = mmfr0 & 0x7; > - ipa_max = id_aa64mmfr0_parange_to_phys_shift(parange); > + ipa_max = id_aa64mmfr0_iparange(mmfr0); Why drop id_aa64mmfr0_parange_to_phys_shift()? > if (ipa_max < get_kvm_ipa_limit()) { > pr_crit("CPU%d: IPA range mismatch\n", smp_processor_id()); > cpu_die_early(); > diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c > index 841b492ff334..2e4da75d79ea 100644 > --- a/arch/arm64/kvm/reset.c > +++ b/arch/arm64/kvm/reset.c > @@ -347,10 +347,10 @@ u32 get_kvm_ipa_limit(void) > > void kvm_set_ipa_limit(void) > { > - unsigned int ipa_max, pa_max, va_max, parange; > + unsigned int ipa_max, pa_max, va_max; > > - parange = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1) & 0x7; > - pa_max = id_aa64mmfr0_parange_to_phys_shift(parange); > + pa_max = id_aa64mmfr0_iparange(read_sanitised_ftr_reg > + (SYS_ID_AA64MMFR0_EL1)); Weird style here. the '(' should be kept next to the function name. > > /* Clamp the IPA limit to the PA size supported by the kernel */ > ipa_max = (pa_max > PHYS_MASK_SHIFT) ? PHYS_MASK_SHIFT : pa_max; > @@ -411,7 +411,8 @@ int kvm_arm_setup_stage2(struct kvm *kvm, unsigned long type) > phys_shift = KVM_PHYS_SHIFT; > } > > - parange = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1) & 7; > + parange = id_aa64mmfr0_parange(read_sanitised_ftr_reg > + (SYS_ID_AA64MMFR0_EL1)); Can't we add a system_ipa_range() helper, and avoid more boilerplate in each of these? e.g. int system_ipa_range(void) { u64 mmfr0; int parange; mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1); parange = cpuid_feature_extract_unsigned_field(mmfr0, ID_AA64MMFR0_PARANGE_SHIFT); return parange; } ... we do similar for the system_supports_xxx() helpers. Thanks, Mark. _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
