> On Dec 20, 2023, at 13:18, Nanyong Sun <sunnanyong@xxxxxxxxxx> wrote: > > Implement vmemmap_update_pmd and vmemmap_update_pte on arm64 to do > BBM(break-before-make) logic when change the page table of vmemmap > address, they will under the init_mm.page_table_lock. > If a translation fault of vmemmap address concurrently happened after > pte/pmd cleared, vmemmap page fault handler will acquire the > init_mm.page_table_lock to wait for vmemmap update to complete, > by then the virtual address is valid again, so PF can return and > access can continue. > In other case, do the traditional kernel fault. > > Implement vmemmap_flush_tlb_all/range on arm64 with nothing > to do because tlb already flushed in every single BBM. > > Signed-off-by: Nanyong Sun <sunnanyong@xxxxxxxxxx> > --- > arch/arm64/include/asm/esr.h | 4 ++ > arch/arm64/include/asm/mmu.h | 20 +++++++++ > arch/arm64/mm/fault.c | 78 ++++++++++++++++++++++++++++++++++-- > arch/arm64/mm/mmu.c | 28 +++++++++++++ > 4 files changed, 127 insertions(+), 3 deletions(-) > > diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h > index ae35939f395b..1c63256efd25 100644 > --- a/arch/arm64/include/asm/esr.h > +++ b/arch/arm64/include/asm/esr.h > @@ -116,6 +116,10 @@ > #define ESR_ELx_FSC_SERROR (0x11) > #define ESR_ELx_FSC_ACCESS (0x08) > #define ESR_ELx_FSC_FAULT (0x04) > +#define ESR_ELx_FSC_FAULT_L0 (0x04) > +#define ESR_ELx_FSC_FAULT_L1 (0x05) > +#define ESR_ELx_FSC_FAULT_L2 (0x06) > +#define ESR_ELx_FSC_FAULT_L3 (0x07) > #define ESR_ELx_FSC_PERM (0x0C) > #define ESR_ELx_FSC_SEA_TTW0 (0x14) > #define ESR_ELx_FSC_SEA_TTW1 (0x15) > diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h > index 2fcf51231d6e..b553bc37c925 100644 > --- a/arch/arm64/include/asm/mmu.h > +++ b/arch/arm64/include/asm/mmu.h > @@ -76,5 +76,25 @@ extern bool kaslr_requires_kpti(void); > #define INIT_MM_CONTEXT(name) \ > .pgd = init_pg_dir, > > +#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP > +void vmemmap_update_pmd(unsigned long addr, pmd_t *pmdp, pte_t *ptep); > +#define vmemmap_update_pmd vmemmap_update_pmd > +void vmemmap_update_pte(unsigned long addr, pte_t *ptep, pte_t pte); > +#define vmemmap_update_pte vmemmap_update_pte > + > +static inline void vmemmap_flush_tlb_all(void) > +{ > + /* do nothing, already flushed tlb in every single BBM */ > +} > +#define vmemmap_flush_tlb_all vmemmap_flush_tlb_all > + > +static inline void vmemmap_flush_tlb_range(unsigned long start, > + unsigned long end) > +{ > + /* do nothing, already flushed tlb in every single BBM */ > +} > +#define vmemmap_flush_tlb_range vmemmap_flush_tlb_range > +#endif I think those declaration related to TLB flushing should be moved to arch/arm64/include/asm/tlbflush.h since we do not include <asm/mmu.h> explicitly in hugetlb_vmemmap.c and its functionality is to flush TLB. Luckily, <asm/tlbflush.h> is included by hugetlb_vmemmap.c. Additionally, vmemmap_update_pmd/pte helpers should be moved to arch/arm64/include/asm/pgtable.h since it is really pgtable related operations. Thanks.