Bharata B Rao <bhar...@linux.ibm.com> writes: > Make GTSE an MMU feature and enable it by default for radix. > However for guest, conditionally enable it if hypervisor supports > it via OV5 vector. Let prom_init ask for radix GTSE only if the > support exists. > > Having GTSE as an MMU feature will make it easy to enable radix > without GTSE. Currently radix assumes GTSE is enabled by default. >
Reviewed-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com> > Signed-off-by: Bharata B Rao <bhar...@linux.ibm.com> > --- > arch/powerpc/include/asm/mmu.h | 4 ++++ > arch/powerpc/kernel/dt_cpu_ftrs.c | 1 + > arch/powerpc/kernel/prom_init.c | 13 ++++++++----- > arch/powerpc/mm/init_64.c | 5 ++++- > 4 files changed, 17 insertions(+), 6 deletions(-) > > diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h > index f4ac25d4df05..884d51995934 100644 > --- a/arch/powerpc/include/asm/mmu.h > +++ b/arch/powerpc/include/asm/mmu.h > @@ -28,6 +28,9 @@ > * Individual features below. > */ > > +/* Guest Translation Shootdown Enable */ > +#define MMU_FTR_GTSE ASM_CONST(0x00001000) > + > /* > * Support for 68 bit VA space. We added that from ISA 2.05 > */ > @@ -173,6 +176,7 @@ enum { > #endif > #ifdef CONFIG_PPC_RADIX_MMU > MMU_FTR_TYPE_RADIX | > + MMU_FTR_GTSE | > #ifdef CONFIG_PPC_KUAP > MMU_FTR_RADIX_KUAP | > #endif /* CONFIG_PPC_KUAP */ > diff --git a/arch/powerpc/kernel/dt_cpu_ftrs.c > b/arch/powerpc/kernel/dt_cpu_ftrs.c > index a0edeb391e3e..ac650c233cd9 100644 > --- a/arch/powerpc/kernel/dt_cpu_ftrs.c > +++ b/arch/powerpc/kernel/dt_cpu_ftrs.c > @@ -336,6 +336,7 @@ static int __init feat_enable_mmu_radix(struct > dt_cpu_feature *f) > #ifdef CONFIG_PPC_RADIX_MMU > cur_cpu_spec->mmu_features |= MMU_FTR_TYPE_RADIX; > cur_cpu_spec->mmu_features |= MMU_FTRS_HASH_BASE; > + cur_cpu_spec->mmu_features |= MMU_FTR_GTSE; > cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_MMU; > > return 1; > diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c > index 90c604d00b7d..cbc605cfdec0 100644 > --- a/arch/powerpc/kernel/prom_init.c > +++ b/arch/powerpc/kernel/prom_init.c > @@ -1336,12 +1336,15 @@ static void __init prom_check_platform_support(void) > } > } > > - if (supported.radix_mmu && supported.radix_gtse && > - IS_ENABLED(CONFIG_PPC_RADIX_MMU)) { > - /* Radix preferred - but we require GTSE for now */ > - prom_debug("Asking for radix with GTSE\n"); > + if (supported.radix_mmu && IS_ENABLED(CONFIG_PPC_RADIX_MMU)) { > + /* Radix preferred - Check if GTSE is also supported */ > + prom_debug("Asking for radix\n"); > ibm_architecture_vec.vec5.mmu = OV5_FEAT(OV5_MMU_RADIX); > - ibm_architecture_vec.vec5.radix_ext = OV5_FEAT(OV5_RADIX_GTSE); > + if (supported.radix_gtse) > + ibm_architecture_vec.vec5.radix_ext = > + OV5_FEAT(OV5_RADIX_GTSE); > + else > + prom_debug("Radix GTSE isn't supported\n"); > } else if (supported.hash_mmu) { > /* Default to hash mmu (if we can) */ > prom_debug("Asking for hash\n"); > diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c > index bc73abf0bc25..152aa0200cef 100644 > --- a/arch/powerpc/mm/init_64.c > +++ b/arch/powerpc/mm/init_64.c > @@ -407,12 +407,15 @@ static void __init early_check_vec5(void) > if (!(vec5[OV5_INDX(OV5_RADIX_GTSE)] & > OV5_FEAT(OV5_RADIX_GTSE))) { > pr_warn("WARNING: Hypervisor doesn't support RADIX with > GTSE\n"); > - } > + cur_cpu_spec->mmu_features &= ~MMU_FTR_GTSE; > + } else > + cur_cpu_spec->mmu_features |= MMU_FTR_GTSE; > /* Do radix anyway - the hypervisor said we had to */ > cur_cpu_spec->mmu_features |= MMU_FTR_TYPE_RADIX; > } else if (mmu_supported == OV5_FEAT(OV5_MMU_HASH)) { > /* Hypervisor only supports hash - disable radix */ > cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; > + cur_cpu_spec->mmu_features &= ~MMU_FTR_GTSE; > } > } > > -- > 2.21.3