Message ID | 20211004151142.256251-2-sourabhjain@linux.ibm.com (mailing list archive) |
---|---|
State | Superseded |
Headers | show |
Series | Update crashkernel offset to allow kernel to boot on large config LPARs | expand |
Related | show |
On 10/4/21 20:41, Sourabh Jain wrote: > From: Mahesh Salgaonkar <mahesh@linux.ibm.com> > > On system with radix support available, early_radix_enabled() starts > returning true for a small window (until mmu_early_init_devtree() is > called) even when radix mode disabled on kernel command line. This causes > ppc64_bolted_size() to return ULONG_MAX in HPT mode instead of supported > segment size, during boot cpu paca allocation. > > With kernel command line = "... disable_radix": > > early_init_devtree: <- early_radix_enabled() = false > early_init_dt_scan_cpus: <- early_radix_enabled() = false > ... > check_cpu_pa_features: <- early_radix_enabled() = false > ... ^ <- early_radix_enabled() = TRUE > allocate_paca: | <- early_radix_enabled() = TRUE > ... | > ppc64_bolted_size: | <- early_radix_enabled() = TRUE > if (early_radix_enabled())| <- early_radix_enabled() = TRUE > return ULONG_MAX; | > ... | > ... | <- early_radix_enabled() = TRUE > ... | <- early_radix_enabled() = TRUE > mmu_early_init_devtree() V > ... <- early_radix_enabled() = false > > So far we have not seen any issue because allocate_paca() takes minimum of > ppc64_bolted_size and rma_size while allocating paca. However it is better > to close this window by fixing up the mmu features as early as possible. > This fixes early_radix_enabled() and ppc64_bolted_size() to return valid > values in radix disable mode. This patch will help subsequent patch to > depend on early_radix_enabled() check while detecting supported segment > size in HPT mode. > > Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com> > Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com> > Reported-and-tested-by: Abdul haleem <abdhalee@linux.vnet.ibm.com> > --- > arch/powerpc/include/asm/book3s/64/mmu.h | 1 + > arch/powerpc/include/asm/mmu.h | 1 + > arch/powerpc/kernel/prom.c | 1 + > arch/powerpc/mm/init_64.c | 5 ++++- > 4 files changed, 7 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h b/arch/powerpc/include/asm/book3s/64/mmu.h > index c02f42d1031e..69a89fa1330d 100644 > --- a/arch/powerpc/include/asm/book3s/64/mmu.h > +++ b/arch/powerpc/include/asm/book3s/64/mmu.h > @@ -197,6 +197,7 @@ extern int mmu_vmemmap_psize; > extern int mmu_io_psize; > > /* MMU initialization */ > +void mmu_cpu_feature_fixup(void); > void mmu_early_init_devtree(void); > void hash__early_init_devtree(void); > void radix__early_init_devtree(void); > diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h > index 8abe8e42e045..c8eafd401fe9 100644 > --- a/arch/powerpc/include/asm/mmu.h > +++ b/arch/powerpc/include/asm/mmu.h > @@ -401,6 +401,7 @@ extern void early_init_mmu(void); > extern void early_init_mmu_secondary(void); > extern void setup_initial_memory_limit(phys_addr_t first_memblock_base, > phys_addr_t first_memblock_size); > +static inline void mmu_cpu_feature_fixup(void) { } > static inline void mmu_early_init_devtree(void) { } > > static inline void pkey_early_init_devtree(void) {} > diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c > index 2e67588f6f6e..1727a3abe6c1 100644 > --- a/arch/powerpc/kernel/prom.c > +++ b/arch/powerpc/kernel/prom.c > @@ -380,6 +380,7 @@ static int __init early_init_dt_scan_cpus(unsigned long node, > check_cpu_pa_features(node); > } > > + mmu_cpu_feature_fixup(); can you do that call inside check_cpu_pa_features? or is it because we have the same issue with baremetal platforms? Can we also rename this to indicate we are sanitizing the feature flag based on kernel command line. Something like /* Update cpu features based on kernel command line */ update_cpu_features(); > identical_pvr_fixup(node); > init_mmu_slb_size(node); > > diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c > index 386be136026e..9ed452605a2c 100644 > --- a/arch/powerpc/mm/init_64.c > +++ b/arch/powerpc/mm/init_64.c > @@ -437,12 +437,15 @@ static void __init early_check_vec5(void) > } > } > > -void __init mmu_early_init_devtree(void) > +void __init mmu_cpu_feature_fixup(void) > { > /* Disable radix mode based on kernel command line. */ > if (disable_radix) > cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; > +} > > +void __init mmu_early_init_devtree(void) > +{ > /* > * Check /chosen/ibm,architecture-vec-5 if running as a guest. > * When running bare-metal, we can use radix if we like >
On 2021-10-04 21:02:21 Mon, Aneesh Kumar K.V wrote: > On 10/4/21 20:41, Sourabh Jain wrote: > > From: Mahesh Salgaonkar <mahesh@linux.ibm.com> > > > > On system with radix support available, early_radix_enabled() starts > > returning true for a small window (until mmu_early_init_devtree() is > > called) even when radix mode disabled on kernel command line. This causes > > ppc64_bolted_size() to return ULONG_MAX in HPT mode instead of supported > > segment size, during boot cpu paca allocation. > > > > With kernel command line = "... disable_radix": > > > > early_init_devtree: <- early_radix_enabled() = false > > early_init_dt_scan_cpus: <- early_radix_enabled() = false > > ... > > check_cpu_pa_features: <- early_radix_enabled() = false > > ... ^ <- early_radix_enabled() = TRUE > > allocate_paca: | <- early_radix_enabled() = TRUE > > ... | > > ppc64_bolted_size: | <- early_radix_enabled() = TRUE > > if (early_radix_enabled())| <- early_radix_enabled() = TRUE > > return ULONG_MAX; | > > ... | > > ... | <- early_radix_enabled() = TRUE > > ... | <- early_radix_enabled() = TRUE > > mmu_early_init_devtree() V > > ... <- early_radix_enabled() = false > > > > So far we have not seen any issue because allocate_paca() takes minimum of > > ppc64_bolted_size and rma_size while allocating paca. However it is better > > to close this window by fixing up the mmu features as early as possible. > > This fixes early_radix_enabled() and ppc64_bolted_size() to return valid > > values in radix disable mode. This patch will help subsequent patch to > > depend on early_radix_enabled() check while detecting supported segment > > size in HPT mode. > > > > Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com> > > Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com> > > Reported-and-tested-by: Abdul haleem <abdhalee@linux.vnet.ibm.com> > > --- > > arch/powerpc/include/asm/book3s/64/mmu.h | 1 + > > arch/powerpc/include/asm/mmu.h | 1 + > > arch/powerpc/kernel/prom.c | 1 + > > arch/powerpc/mm/init_64.c | 5 ++++- > > 4 files changed, 7 insertions(+), 1 deletion(-) > > > > diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h b/arch/powerpc/include/asm/book3s/64/mmu.h > > index c02f42d1031e..69a89fa1330d 100644 > > --- a/arch/powerpc/include/asm/book3s/64/mmu.h > > +++ b/arch/powerpc/include/asm/book3s/64/mmu.h > > @@ -197,6 +197,7 @@ extern int mmu_vmemmap_psize; > > extern int mmu_io_psize; > > /* MMU initialization */ > > +void mmu_cpu_feature_fixup(void); > > void mmu_early_init_devtree(void); > > void hash__early_init_devtree(void); > > void radix__early_init_devtree(void); > > diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h > > index 8abe8e42e045..c8eafd401fe9 100644 > > --- a/arch/powerpc/include/asm/mmu.h > > +++ b/arch/powerpc/include/asm/mmu.h > > @@ -401,6 +401,7 @@ extern void early_init_mmu(void); > > extern void early_init_mmu_secondary(void); > > extern void setup_initial_memory_limit(phys_addr_t first_memblock_base, > > phys_addr_t first_memblock_size); > > +static inline void mmu_cpu_feature_fixup(void) { } > > static inline void mmu_early_init_devtree(void) { } > > static inline void pkey_early_init_devtree(void) {} > > diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c > > index 2e67588f6f6e..1727a3abe6c1 100644 > > --- a/arch/powerpc/kernel/prom.c > > +++ b/arch/powerpc/kernel/prom.c > > @@ -380,6 +380,7 @@ static int __init early_init_dt_scan_cpus(unsigned long node, > > check_cpu_pa_features(node); > > } > > + mmu_cpu_feature_fixup(); > > can you do that call inside check_cpu_pa_features? or is it because we have > the same issue with baremetal platforms? Yup same issue exist on baremetal as well in case of dt_cpu_ftrs_in_use is true. Hence calling it after the if (!dt_cpu_ftrs_in_use) code block takes care of both pseries and baremetal platforms. > > Can we also rename this to indicate we are sanitizing the feature flag based > on kernel command line. Something like > > /* Update cpu features based on kernel command line */ > update_cpu_features(); Sure will do. Thanks for your review. -Mahesh.
diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h b/arch/powerpc/include/asm/book3s/64/mmu.h index c02f42d1031e..69a89fa1330d 100644 --- a/arch/powerpc/include/asm/book3s/64/mmu.h +++ b/arch/powerpc/include/asm/book3s/64/mmu.h @@ -197,6 +197,7 @@ extern int mmu_vmemmap_psize; extern int mmu_io_psize; /* MMU initialization */ +void mmu_cpu_feature_fixup(void); void mmu_early_init_devtree(void); void hash__early_init_devtree(void); void radix__early_init_devtree(void); diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h index 8abe8e42e045..c8eafd401fe9 100644 --- a/arch/powerpc/include/asm/mmu.h +++ b/arch/powerpc/include/asm/mmu.h @@ -401,6 +401,7 @@ extern void early_init_mmu(void); extern void early_init_mmu_secondary(void); extern void setup_initial_memory_limit(phys_addr_t first_memblock_base, phys_addr_t first_memblock_size); +static inline void mmu_cpu_feature_fixup(void) { } static inline void mmu_early_init_devtree(void) { } static inline void pkey_early_init_devtree(void) {} diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c index 2e67588f6f6e..1727a3abe6c1 100644 --- a/arch/powerpc/kernel/prom.c +++ b/arch/powerpc/kernel/prom.c @@ -380,6 +380,7 @@ static int __init early_init_dt_scan_cpus(unsigned long node, check_cpu_pa_features(node); } + mmu_cpu_feature_fixup(); identical_pvr_fixup(node); init_mmu_slb_size(node); diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c index 386be136026e..9ed452605a2c 100644 --- a/arch/powerpc/mm/init_64.c +++ b/arch/powerpc/mm/init_64.c @@ -437,12 +437,15 @@ static void __init early_check_vec5(void) } } -void __init mmu_early_init_devtree(void) +void __init mmu_cpu_feature_fixup(void) { /* Disable radix mode based on kernel command line. */ if (disable_radix) cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; +} +void __init mmu_early_init_devtree(void) +{ /* * Check /chosen/ibm,architecture-vec-5 if running as a guest. * When running bare-metal, we can use radix if we like