| Message ID | 20230417060618.639395-1-vincent.chen@sifive.com (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
| Series | [v3] riscv: mm: execute local TLB flush after populating vmemmap | expand |
| Context | Check | Description |
|---|---|---|
| conchuod/cover_letter | success | Single patches do not need cover letters |
| conchuod/tree_selection | success | Guessed tree name to be fixes at HEAD 1b50f956c8fe |
| conchuod/fixes_present | success | Fixes tag present in non-next series |
| conchuod/maintainers_pattern | success | MAINTAINERS pattern errors before the patch: 1 and now 1 |
| conchuod/verify_signedoff | success | Signed-off-by tag matches author and committer |
| conchuod/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| conchuod/build_rv64_clang_allmodconfig | success | Errors and warnings before: 3288 this patch: 3288 |
| conchuod/module_param | success | Was 0 now: 0 |
| conchuod/build_rv64_gcc_allmodconfig | success | Errors and warnings before: 17609 this patch: 17609 |
| conchuod/build_rv32_defconfig | success | Build OK |
| conchuod/dtb_warn_rv64 | success | Errors and warnings before: 3 this patch: 3 |
| conchuod/header_inline | success | No static functions without inline keyword in header files |
| conchuod/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 28 lines checked |
| conchuod/source_inline | success | Was 0 now: 0 |
| conchuod/build_rv64_nommu_k210_defconfig | success | Build OK |
| conchuod/verify_fixes | success | Fixes tag looks correct |
| conchuod/build_rv64_nommu_virt_defconfig | success | Build OK |
On Sun, 16 Apr 2023 23:06:18 PDT (-0700), vincent.chen@sifive.com wrote: > The spare_init() calls memmap_populate() many times to create VA to PA > mapping for the VMEMMAP area, where all "struct page" are located once > CONFIG_SPARSEMEM_VMEMMAP is defined. These "struct page" are later > initialized in the zone_sizes_init() function. However, during this > process, no sfence.vma instruction is executed for this VMEMMAP area. > This omission may cause the hart to fail to perform page table walk > because some data related to the address translation is invisible to the > hart. To solve this issue, the local_flush_tlb_kernel_range() is called > right after the spare_init() to execute a sfence.vma instruction for the > VMEMMAP area, ensuring that all data related to the address translation > is visible to the hart. > > Fixes: d95f1a542c3d ("RISC-V: Implement sparsemem") > Signed-off-by: Vincent Chen <vincent.chen@sifive.com> > Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> > Reviewed-by: Andrew Jones <ajones@ventanamicro.com> > --- > arch/riscv/include/asm/tlbflush.h | 7 +++++++ > arch/riscv/mm/init.c | 5 +++++ > 2 files changed, 12 insertions(+) > > diff --git a/arch/riscv/include/asm/tlbflush.h b/arch/riscv/include/asm/tlbflush.h > index a09196f8de68..f9d3712bd93b 100644 > --- a/arch/riscv/include/asm/tlbflush.h > +++ b/arch/riscv/include/asm/tlbflush.h > @@ -61,4 +61,11 @@ static inline void flush_tlb_kernel_range(unsigned long start, > flush_tlb_all(); > } > > +/* Flush a range of kernel pages without broadcasting */ > +static inline void local_flush_tlb_kernel_range(unsigned long start, > + unsigned long end) > +{ > + local_flush_tlb_all(); Why is this a global flush, istead of a range-based one? We should probably make the same change for flush_tlb_kernel_range(), though that's not a fix. > +} > + > #endif /* _ASM_RISCV_TLBFLUSH_H */ > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > index 0f14f4a8d179..bcf365cbbcc1 100644 > --- a/arch/riscv/mm/init.c > +++ b/arch/riscv/mm/init.c > @@ -1221,6 +1221,10 @@ void __init misc_mem_init(void) > early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT); > arch_numa_init(); > sparse_init(); > +#ifdef CONFIG_SPARSEMEM_VMEMMAP > + /* The entire VMEMMAP region has been populated. Flush TLB for this region */ > + local_flush_tlb_kernel_range(VMEMMAP_START, VMEMMAP_END); > +#endif > zone_sizes_init(); > reserve_crashkernel(); > memblock_dump_all(); > @@ -1230,6 +1234,7 @@ void __init misc_mem_init(void) > int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, > struct vmem_altmap *altmap) > { > + /* Defer the required TLB flush until the entire VMEMMAP region has been populated */ > return vmemmap_populate_basepages(start, end, node, NULL); > } > #endif
On Tue, May 2, 2023 at 2:18 AM Palmer Dabbelt <palmer@dabbelt.com> wrote: > > On Sun, 16 Apr 2023 23:06:18 PDT (-0700), vincent.chen@sifive.com wrote: > > The spare_init() calls memmap_populate() many times to create VA to PA > > mapping for the VMEMMAP area, where all "struct page" are located once > > CONFIG_SPARSEMEM_VMEMMAP is defined. These "struct page" are later > > initialized in the zone_sizes_init() function. However, during this > > process, no sfence.vma instruction is executed for this VMEMMAP area. > > This omission may cause the hart to fail to perform page table walk > > because some data related to the address translation is invisible to the > > hart. To solve this issue, the local_flush_tlb_kernel_range() is called > > right after the spare_init() to execute a sfence.vma instruction for the > > VMEMMAP area, ensuring that all data related to the address translation > > is visible to the hart. > > > > Fixes: d95f1a542c3d ("RISC-V: Implement sparsemem") > > Signed-off-by: Vincent Chen <vincent.chen@sifive.com> > > Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> > > Reviewed-by: Andrew Jones <ajones@ventanamicro.com> > > --- > > arch/riscv/include/asm/tlbflush.h | 7 +++++++ > > arch/riscv/mm/init.c | 5 +++++ > > 2 files changed, 12 insertions(+) > > > > diff --git a/arch/riscv/include/asm/tlbflush.h b/arch/riscv/include/asm/tlbflush.h > > index a09196f8de68..f9d3712bd93b 100644 > > --- a/arch/riscv/include/asm/tlbflush.h > > +++ b/arch/riscv/include/asm/tlbflush.h > > @@ -61,4 +61,11 @@ static inline void flush_tlb_kernel_range(unsigned long start, > > flush_tlb_all(); > > } > > > > +/* Flush a range of kernel pages without broadcasting */ > > +static inline void local_flush_tlb_kernel_range(unsigned long start, > > + unsigned long end) > > +{ > > + local_flush_tlb_all(); > > Why is this a global flush, istead of a range-based one? We should > probably make the same change for flush_tlb_kernel_range(), though > that's not a fix. You're right, but the current implementation of flush_tlb_range will ultimately call flush_tlb_all if the size > PAGE_SIZE, which is very likely in this case. Anyway, I have a patchset almost ready that improves the tlb flush routines, and I noted that I had to fix this function once merged. > > > +} > > + > > #endif /* _ASM_RISCV_TLBFLUSH_H */ > > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > > index 0f14f4a8d179..bcf365cbbcc1 100644 > > --- a/arch/riscv/mm/init.c > > +++ b/arch/riscv/mm/init.c > > @@ -1221,6 +1221,10 @@ void __init misc_mem_init(void) > > early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT); > > arch_numa_init(); > > sparse_init(); > > +#ifdef CONFIG_SPARSEMEM_VMEMMAP > > + /* The entire VMEMMAP region has been populated. Flush TLB for this region */ > > + local_flush_tlb_kernel_range(VMEMMAP_START, VMEMMAP_END); > > +#endif > > zone_sizes_init(); > > reserve_crashkernel(); > > memblock_dump_all(); > > @@ -1230,6 +1234,7 @@ void __init misc_mem_init(void) > > int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, > > struct vmem_altmap *altmap) > > { > > + /* Defer the required TLB flush until the entire VMEMMAP region has been populated */ > > return vmemmap_populate_basepages(start, end, node, NULL); > > } > > #endif
On Tue, May 2, 2023 at 8:16 PM Alexandre Ghiti <alexghiti@rivosinc.com> wrote: > > On Tue, May 2, 2023 at 2:18 AM Palmer Dabbelt <palmer@dabbelt.com> wrote: > > > > On Sun, 16 Apr 2023 23:06:18 PDT (-0700), vincent.chen@sifive.com wrote: > > > The spare_init() calls memmap_populate() many times to create VA to PA > > > mapping for the VMEMMAP area, where all "struct page" are located once > > > CONFIG_SPARSEMEM_VMEMMAP is defined. These "struct page" are later > > > initialized in the zone_sizes_init() function. However, during this > > > process, no sfence.vma instruction is executed for this VMEMMAP area. > > > This omission may cause the hart to fail to perform page table walk > > > because some data related to the address translation is invisible to the > > > hart. To solve this issue, the local_flush_tlb_kernel_range() is called > > > right after the spare_init() to execute a sfence.vma instruction for the > > > VMEMMAP area, ensuring that all data related to the address translation > > > is visible to the hart. > > > > > > Fixes: d95f1a542c3d ("RISC-V: Implement sparsemem") > > > Signed-off-by: Vincent Chen <vincent.chen@sifive.com> > > > Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> > > > Reviewed-by: Andrew Jones <ajones@ventanamicro.com> > > > --- > > > arch/riscv/include/asm/tlbflush.h | 7 +++++++ > > > arch/riscv/mm/init.c | 5 +++++ > > > 2 files changed, 12 insertions(+) > > > > > > diff --git a/arch/riscv/include/asm/tlbflush.h b/arch/riscv/include/asm/tlbflush.h > > > index a09196f8de68..f9d3712bd93b 100644 > > > --- a/arch/riscv/include/asm/tlbflush.h > > > +++ b/arch/riscv/include/asm/tlbflush.h > > > @@ -61,4 +61,11 @@ static inline void flush_tlb_kernel_range(unsigned long start, > > > flush_tlb_all(); > > > } > > > > > > +/* Flush a range of kernel pages without broadcasting */ > > > +static inline void local_flush_tlb_kernel_range(unsigned long start, > > > + unsigned long end) > > > +{ > > > + local_flush_tlb_all(); > > > > Why is this a global flush, istead of a range-based one? We should > > probably make the same change for flush_tlb_kernel_range(), though > > that's not a fix. > > You're right, but the current implementation of flush_tlb_range will > ultimately call flush_tlb_all if the size > PAGE_SIZE, which is very > likely in this case. Anyway, I have a patchset almost ready that > improves the tlb flush routines, and I noted that I had to fix this > function once merged. > I agree with Alexandre that it's highly probable that the size will be greater than PAGE_SIZE in this case. However, I must admit that this implementation is not suitable for the case where the size is less than or equal to PAGE_SIZE. I am willing to wait for Alexandre's patch and rebase my patch on top of his If you believe it is a better approach. > > > > > +} > > > + > > > #endif /* _ASM_RISCV_TLBFLUSH_H */ > > > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > > > index 0f14f4a8d179..bcf365cbbcc1 100644 > > > --- a/arch/riscv/mm/init.c > > > +++ b/arch/riscv/mm/init.c > > > @@ -1221,6 +1221,10 @@ void __init misc_mem_init(void) > > > early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT); > > > arch_numa_init(); > > > sparse_init(); > > > +#ifdef CONFIG_SPARSEMEM_VMEMMAP > > > + /* The entire VMEMMAP region has been populated. Flush TLB for this region */ > > > + local_flush_tlb_kernel_range(VMEMMAP_START, VMEMMAP_END); > > > +#endif > > > zone_sizes_init(); > > > reserve_crashkernel(); > > > memblock_dump_all(); > > > @@ -1230,6 +1234,7 @@ void __init misc_mem_init(void) > > > int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, > > > struct vmem_altmap *altmap) > > > { > > > + /* Defer the required TLB flush until the entire VMEMMAP region has been populated */ > > > return vmemmap_populate_basepages(start, end, node, NULL); > > > } > > > #endif
Hi Vincent, On 04/05/2023 11:13, Vincent Chen wrote: > On Tue, May 2, 2023 at 8:16 PM Alexandre Ghiti <alexghiti@rivosinc.com> wrote: >> On Tue, May 2, 2023 at 2:18 AM Palmer Dabbelt <palmer@dabbelt.com> wrote: >>> On Sun, 16 Apr 2023 23:06:18 PDT (-0700), vincent.chen@sifive.com wrote: >>>> The spare_init() calls memmap_populate() many times to create VA to PA >>>> mapping for the VMEMMAP area, where all "struct page" are located once >>>> CONFIG_SPARSEMEM_VMEMMAP is defined. These "struct page" are later >>>> initialized in the zone_sizes_init() function. However, during this >>>> process, no sfence.vma instruction is executed for this VMEMMAP area. >>>> This omission may cause the hart to fail to perform page table walk >>>> because some data related to the address translation is invisible to the >>>> hart. To solve this issue, the local_flush_tlb_kernel_range() is called >>>> right after the spare_init() to execute a sfence.vma instruction for the >>>> VMEMMAP area, ensuring that all data related to the address translation >>>> is visible to the hart. >>>> >>>> Fixes: d95f1a542c3d ("RISC-V: Implement sparsemem") >>>> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> >>>> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> >>>> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> >>>> --- >>>> arch/riscv/include/asm/tlbflush.h | 7 +++++++ >>>> arch/riscv/mm/init.c | 5 +++++ >>>> 2 files changed, 12 insertions(+) >>>> >>>> diff --git a/arch/riscv/include/asm/tlbflush.h b/arch/riscv/include/asm/tlbflush.h >>>> index a09196f8de68..f9d3712bd93b 100644 >>>> --- a/arch/riscv/include/asm/tlbflush.h >>>> +++ b/arch/riscv/include/asm/tlbflush.h >>>> @@ -61,4 +61,11 @@ static inline void flush_tlb_kernel_range(unsigned long start, >>>> flush_tlb_all(); >>>> } >>>> >>>> +/* Flush a range of kernel pages without broadcasting */ >>>> +static inline void local_flush_tlb_kernel_range(unsigned long start, >>>> + unsigned long end) >>>> +{ >>>> + local_flush_tlb_all(); >>> Why is this a global flush, istead of a range-based one? We should >>> probably make the same change for flush_tlb_kernel_range(), though >>> that's not a fix. >> You're right, but the current implementation of flush_tlb_range will >> ultimately call flush_tlb_all if the size > PAGE_SIZE, which is very >> likely in this case. Anyway, I have a patchset almost ready that >> improves the tlb flush routines, and I noted that I had to fix this >> function once merged. >> > I agree with Alexandre that it's highly probable that the size will be > greater than PAGE_SIZE in this case. However, I must admit that this > implementation is not suitable for the case where the size is less > than or equal to PAGE_SIZE. I am willing to wait for Alexandre's patch > and rebase my patch on top of his If you believe it is a better > approach. My patchset was merged in 6.6, so you can now rebase this :) Let me know if I can help. Thanks, Alex > >>>> +} >>>> + >>>> #endif /* _ASM_RISCV_TLBFLUSH_H */ >>>> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c >>>> index 0f14f4a8d179..bcf365cbbcc1 100644 >>>> --- a/arch/riscv/mm/init.c >>>> +++ b/arch/riscv/mm/init.c >>>> @@ -1221,6 +1221,10 @@ void __init misc_mem_init(void) >>>> early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT); >>>> arch_numa_init(); >>>> sparse_init(); >>>> +#ifdef CONFIG_SPARSEMEM_VMEMMAP >>>> + /* The entire VMEMMAP region has been populated. Flush TLB for this region */ >>>> + local_flush_tlb_kernel_range(VMEMMAP_START, VMEMMAP_END); >>>> +#endif >>>> zone_sizes_init(); >>>> reserve_crashkernel(); >>>> memblock_dump_all(); >>>> @@ -1230,6 +1234,7 @@ void __init misc_mem_init(void) >>>> int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, >>>> struct vmem_altmap *altmap) >>>> { >>>> + /* Defer the required TLB flush until the entire VMEMMAP region has been populated */ >>>> return vmemmap_populate_basepages(start, end, node, NULL); >>>> } >>>> #endif > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv
On 12/12/2023 06:42, Vincent Chen wrote: > > > On Mon, Dec 11, 2023 at 4:57 PM Alexandre Ghiti <alex@ghiti.fr> wrote: > > Hi Vincent, > > On 04/05/2023 11:13, Vincent Chen wrote: > > On Tue, May 2, 2023 at 8:16 PM Alexandre Ghiti > <alexghiti@rivosinc.com> wrote: > >> On Tue, May 2, 2023 at 2:18 AM Palmer Dabbelt > <palmer@dabbelt.com> wrote: > >>> On Sun, 16 Apr 2023 23:06:18 PDT (-0700), > vincent.chen@sifive.com wrote: > >>>> The spare_init() calls memmap_populate() many times to create > VA to PA > >>>> mapping for the VMEMMAP area, where all "struct page" are > located once > >>>> CONFIG_SPARSEMEM_VMEMMAP is defined. These "struct page" are > later > >>>> initialized in the zone_sizes_init() function. However, > during this > >>>> process, no sfence.vma instruction is executed for this > VMEMMAP area. > >>>> This omission may cause the hart to fail to perform page > table walk > >>>> because some data related to the address translation is > invisible to the > >>>> hart. To solve this issue, the local_flush_tlb_kernel_range() > is called > >>>> right after the spare_init() to execute a sfence.vma > instruction for the > >>>> VMEMMAP area, ensuring that all data related to the address > translation > >>>> is visible to the hart. > >>>> > >>>> Fixes: d95f1a542c3d ("RISC-V: Implement sparsemem") > >>>> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> > >>>> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> > >>>> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> > >>>> --- > >>>> arch/riscv/include/asm/tlbflush.h | 7 +++++++ > >>>> arch/riscv/mm/init.c | 5 +++++ > >>>> 2 files changed, 12 insertions(+) > >>>> > >>>> diff --git a/arch/riscv/include/asm/tlbflush.h > b/arch/riscv/include/asm/tlbflush.h > >>>> index a09196f8de68..f9d3712bd93b 100644 > >>>> --- a/arch/riscv/include/asm/tlbflush.h > >>>> +++ b/arch/riscv/include/asm/tlbflush.h > >>>> @@ -61,4 +61,11 @@ static inline void > flush_tlb_kernel_range(unsigned long start, > >>>> flush_tlb_all(); > >>>> } > >>>> > >>>> +/* Flush a range of kernel pages without broadcasting */ > >>>> +static inline void local_flush_tlb_kernel_range(unsigned > long start, > >>>> + unsigned long end) > >>>> +{ > >>>> + local_flush_tlb_all(); > >>> Why is this a global flush, istead of a range-based one? We > should > >>> probably make the same change for flush_tlb_kernel_range(), though > >>> that's not a fix. > >> You're right, but the current implementation of flush_tlb_range > will > >> ultimately call flush_tlb_all if the size > PAGE_SIZE, which is > very > >> likely in this case. Anyway, I have a patchset almost ready that > >> improves the tlb flush routines, and I noted that I had to fix this > >> function once merged. > >> > > I agree with Alexandre that it's highly probable that the size > will be > > greater than PAGE_SIZE in this case. However, I must admit that this > > implementation is not suitable for the case where the size is less > > than or equal to PAGE_SIZE. I am willing to wait for Alexandre's > patch > > and rebase my patch on top of his If you believe it is a better > > approach. > > > My patchset was merged in 6.6, so you can now rebase this :) Let > me know > if I can help. > > Thanks, > > Alex > > Thank you for the notification. I will rebase my patch on the Linux 6.6. Sorry, it actually landed in 6.7, not 6.6. Thanks! Alex > > Thanks, > Vincent > > > > > >>>> +} > >>>> + > >>>> #endif /* _ASM_RISCV_TLBFLUSH_H */ > >>>> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > >>>> index 0f14f4a8d179..bcf365cbbcc1 100644 > >>>> --- a/arch/riscv/mm/init.c > >>>> +++ b/arch/riscv/mm/init.c > >>>> @@ -1221,6 +1221,10 @@ void __init misc_mem_init(void) > >>>> early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn > << PAGE_SHIFT); > >>>> arch_numa_init(); > >>>> sparse_init(); > >>>> +#ifdef CONFIG_SPARSEMEM_VMEMMAP > >>>> + /* The entire VMEMMAP region has been populated. Flush > TLB for this region */ > >>>> + local_flush_tlb_kernel_range(VMEMMAP_START, VMEMMAP_END); > >>>> +#endif > >>>> zone_sizes_init(); > >>>> reserve_crashkernel(); > >>>> memblock_dump_all(); > >>>> @@ -1230,6 +1234,7 @@ void __init misc_mem_init(void) > >>>> int __meminit vmemmap_populate(unsigned long start, > unsigned long end, int node, > >>>> struct vmem_altmap *altmap) > >>>> { > >>>> + /* Defer the required TLB flush until the entire > VMEMMAP region has been populated */ > >>>> return vmemmap_populate_basepages(start, end, node, NULL); > >>>> } > >>>> #endif > > _______________________________________________ > > linux-riscv mailing list > > linux-riscv@lists.infradead.org > > http://lists.infradead.org/mailman/listinfo/linux-riscv >
diff --git a/arch/riscv/include/asm/tlbflush.h b/arch/riscv/include/asm/tlbflush.h index a09196f8de68..f9d3712bd93b 100644 --- a/arch/riscv/include/asm/tlbflush.h +++ b/arch/riscv/include/asm/tlbflush.h @@ -61,4 +61,11 @@ static inline void flush_tlb_kernel_range(unsigned long start, flush_tlb_all(); } +/* Flush a range of kernel pages without broadcasting */ +static inline void local_flush_tlb_kernel_range(unsigned long start, + unsigned long end) +{ + local_flush_tlb_all(); +} + #endif /* _ASM_RISCV_TLBFLUSH_H */ diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 0f14f4a8d179..bcf365cbbcc1 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -1221,6 +1221,10 @@ void __init misc_mem_init(void) early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT); arch_numa_init(); sparse_init(); +#ifdef CONFIG_SPARSEMEM_VMEMMAP + /* The entire VMEMMAP region has been populated. Flush TLB for this region */ + local_flush_tlb_kernel_range(VMEMMAP_START, VMEMMAP_END); +#endif zone_sizes_init(); reserve_crashkernel(); memblock_dump_all(); @@ -1230,6 +1234,7 @@ void __init misc_mem_init(void) int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, struct vmem_altmap *altmap) { + /* Defer the required TLB flush until the entire VMEMMAP region has been populated */ return vmemmap_populate_basepages(start, end, node, NULL); } #endif
The spare_init() calls memmap_populate() many times to create VA to PA mapping for the VMEMMAP area, where all "struct page" are located once CONFIG_SPARSEMEM_VMEMMAP is defined. These "struct page" are later initialized in the zone_sizes_init() function. However, during this process, no sfence.vma instruction is executed for this VMEMMAP area. This omission may cause the hart to fail to perform page table walk because some data related to the address translation is invisible to the hart. To solve this issue, the local_flush_tlb_kernel_range() is called right after the spare_init() to execute a sfence.vma instruction for the VMEMMAP area, ensuring that all data related to the address translation is visible to the hart. Fixes: d95f1a542c3d ("RISC-V: Implement sparsemem") Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> --- arch/riscv/include/asm/tlbflush.h | 7 +++++++ arch/riscv/mm/init.c | 5 +++++ 2 files changed, 12 insertions(+)