| Message ID | 817d92886fc3b33bcbf6e105ee83a74babb3a5aa.1558547956.git.robin.murphy@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Devmap cleanups + arm64 support | expand |
On Thu, May 23, 2019 at 04:03:16PM +0100, Robin Murphy wrote: > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index 2c41b04708fe..a6378625d47c 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -90,6 +90,7 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; > #define pte_write(pte) (!!(pte_val(pte) & PTE_WRITE)) > #define pte_user_exec(pte) (!(pte_val(pte) & PTE_UXN)) > #define pte_cont(pte) (!!(pte_val(pte) & PTE_CONT)) > +#define pte_devmap(pte) (!!(pte_val(pte) & PTE_DEVMAP)) > > #define pte_cont_addr_end(addr, end) \ > ({ unsigned long __boundary = ((addr) + CONT_PTE_SIZE) & CONT_PTE_MASK; \ > @@ -217,6 +218,11 @@ static inline pmd_t pmd_mkcont(pmd_t pmd) > return __pmd(pmd_val(pmd) | PMD_SECT_CONT); > } > > +static inline pte_t pte_mkdevmap(pte_t pte) > +{ > + return set_pte_bit(pte, __pgprot(PTE_DEVMAP)); > +} > + > static inline void set_pte(pte_t *ptep, pte_t pte) > { > WRITE_ONCE(*ptep, pte); > @@ -381,6 +387,9 @@ static inline int pmd_protnone(pmd_t pmd) > > #define pmd_mkhuge(pmd) (__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT)) > > +#define pmd_devmap(pmd) pte_devmap(pmd_pte(pmd)) > +#define pmd_mkdevmap(pmd) pte_pmd(pte_mkdevmap(pmd_pte(pmd))) > + > #define __pmd_to_phys(pmd) __pte_to_phys(pmd_pte(pmd)) > #define __phys_to_pmd_val(phys) __phys_to_pte_val(phys) > #define pmd_pfn(pmd) ((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT) > @@ -537,6 +546,11 @@ static inline phys_addr_t pud_page_paddr(pud_t pud) > return __pud_to_phys(pud); > } > > +static inline int pud_devmap(pud_t pud) > +{ > + return 0; > +} > + > /* Find an entry in the second-level page table. */ > #define pmd_index(addr) (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1)) > > @@ -624,6 +638,11 @@ static inline phys_addr_t pgd_page_paddr(pgd_t pgd) > > #define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd_val(pgd)) > > +static inline int pgd_devmap(pgd_t pgd) > +{ > + return 0; > +} I think you need to guard this and pXd_devmap() with CONFIG_TRANSPARENT_HUGEPAGE, otherwise you'll conflict with the dummy definitions in mm.h and the build will fail. Will
On 24/05/2019 19:08, Will Deacon wrote: > On Thu, May 23, 2019 at 04:03:16PM +0100, Robin Murphy wrote: >> diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h >> index 2c41b04708fe..a6378625d47c 100644 >> --- a/arch/arm64/include/asm/pgtable.h >> +++ b/arch/arm64/include/asm/pgtable.h >> @@ -90,6 +90,7 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; >> #define pte_write(pte) (!!(pte_val(pte) & PTE_WRITE)) >> #define pte_user_exec(pte) (!(pte_val(pte) & PTE_UXN)) >> #define pte_cont(pte) (!!(pte_val(pte) & PTE_CONT)) >> +#define pte_devmap(pte) (!!(pte_val(pte) & PTE_DEVMAP)) >> >> #define pte_cont_addr_end(addr, end) \ >> ({ unsigned long __boundary = ((addr) + CONT_PTE_SIZE) & CONT_PTE_MASK; \ >> @@ -217,6 +218,11 @@ static inline pmd_t pmd_mkcont(pmd_t pmd) >> return __pmd(pmd_val(pmd) | PMD_SECT_CONT); >> } >> >> +static inline pte_t pte_mkdevmap(pte_t pte) >> +{ >> + return set_pte_bit(pte, __pgprot(PTE_DEVMAP)); >> +} >> + >> static inline void set_pte(pte_t *ptep, pte_t pte) >> { >> WRITE_ONCE(*ptep, pte); >> @@ -381,6 +387,9 @@ static inline int pmd_protnone(pmd_t pmd) >> >> #define pmd_mkhuge(pmd) (__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT)) >> >> +#define pmd_devmap(pmd) pte_devmap(pmd_pte(pmd)) >> +#define pmd_mkdevmap(pmd) pte_pmd(pte_mkdevmap(pmd_pte(pmd))) >> + >> #define __pmd_to_phys(pmd) __pte_to_phys(pmd_pte(pmd)) >> #define __phys_to_pmd_val(phys) __phys_to_pte_val(phys) >> #define pmd_pfn(pmd) ((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT) >> @@ -537,6 +546,11 @@ static inline phys_addr_t pud_page_paddr(pud_t pud) >> return __pud_to_phys(pud); >> } >> >> +static inline int pud_devmap(pud_t pud) >> +{ >> + return 0; >> +} >> + >> /* Find an entry in the second-level page table. */ >> #define pmd_index(addr) (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1)) >> >> @@ -624,6 +638,11 @@ static inline phys_addr_t pgd_page_paddr(pgd_t pgd) >> >> #define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd_val(pgd)) >> >> +static inline int pgd_devmap(pgd_t pgd) >> +{ >> + return 0; >> +} > > I think you need to guard this and pXd_devmap() with > CONFIG_TRANSPARENT_HUGEPAGE, otherwise you'll conflict with the dummy > definitions in mm.h and the build will fail. Ah, right you are - I got as far as catching similar issues with CONFIG_PGTABLE_LEVELS, but apparently I failed to spot the !THP guards in x86 and powerpc. Let me give this one a tweak and test a wider range of configs... Robin.
On 05/24/2019 11:38 PM, Will Deacon wrote: > On Thu, May 23, 2019 at 04:03:16PM +0100, Robin Murphy wrote: >> diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h >> index 2c41b04708fe..a6378625d47c 100644 >> --- a/arch/arm64/include/asm/pgtable.h >> +++ b/arch/arm64/include/asm/pgtable.h >> @@ -90,6 +90,7 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; >> #define pte_write(pte) (!!(pte_val(pte) & PTE_WRITE)) >> #define pte_user_exec(pte) (!(pte_val(pte) & PTE_UXN)) >> #define pte_cont(pte) (!!(pte_val(pte) & PTE_CONT)) >> +#define pte_devmap(pte) (!!(pte_val(pte) & PTE_DEVMAP)) >> >> #define pte_cont_addr_end(addr, end) \ >> ({ unsigned long __boundary = ((addr) + CONT_PTE_SIZE) & CONT_PTE_MASK; \ >> @@ -217,6 +218,11 @@ static inline pmd_t pmd_mkcont(pmd_t pmd) >> return __pmd(pmd_val(pmd) | PMD_SECT_CONT); >> } >> >> +static inline pte_t pte_mkdevmap(pte_t pte) >> +{ >> + return set_pte_bit(pte, __pgprot(PTE_DEVMAP)); >> +} >> + >> static inline void set_pte(pte_t *ptep, pte_t pte) >> { >> WRITE_ONCE(*ptep, pte); >> @@ -381,6 +387,9 @@ static inline int pmd_protnone(pmd_t pmd) >> >> #define pmd_mkhuge(pmd) (__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT)) >> >> +#define pmd_devmap(pmd) pte_devmap(pmd_pte(pmd)) >> +#define pmd_mkdevmap(pmd) pte_pmd(pte_mkdevmap(pmd_pte(pmd))) >> + >> #define __pmd_to_phys(pmd) __pte_to_phys(pmd_pte(pmd)) >> #define __phys_to_pmd_val(phys) __phys_to_pte_val(phys) >> #define pmd_pfn(pmd) ((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT) >> @@ -537,6 +546,11 @@ static inline phys_addr_t pud_page_paddr(pud_t pud) >> return __pud_to_phys(pud); >> } >> >> +static inline int pud_devmap(pud_t pud) >> +{ >> + return 0; >> +} >> + >> /* Find an entry in the second-level page table. */ >> #define pmd_index(addr) (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1)) >> >> @@ -624,6 +638,11 @@ static inline phys_addr_t pgd_page_paddr(pgd_t pgd) >> >> #define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd_val(pgd)) >> >> +static inline int pgd_devmap(pgd_t pgd) >> +{ >> + return 0; >> +} > > I think you need to guard this and pXd_devmap() with > CONFIG_TRANSPARENT_HUGEPAGE, otherwise you'll conflict with the dummy > definitions in mm.h and the build will fail. Just curious why pgd_devmap() also needs to be wrapped in TRANSPARENT_HUGEPAGE config (or use this dummy otherwise). IIUC in case of DAX mappings there can never be a huge mapping at PGD level. It only supports PMD or PUD based ones.
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 4780eb7af842..b5a4611fa4c6 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -23,6 +23,7 @@ config ARM64 select ARCH_HAS_KCOV select ARCH_HAS_KEEPINITRD select ARCH_HAS_MEMBARRIER_SYNC_CORE + select ARCH_HAS_PTE_DEVMAP select ARCH_HAS_PTE_SPECIAL select ARCH_HAS_SETUP_DMA_OPS select ARCH_HAS_SET_MEMORY diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h index 986e41c4c32b..af0b372d15e5 100644 --- a/arch/arm64/include/asm/pgtable-prot.h +++ b/arch/arm64/include/asm/pgtable-prot.h @@ -28,6 +28,7 @@ #define PTE_WRITE (PTE_DBM) /* same as DBM (51) */ #define PTE_DIRTY (_AT(pteval_t, 1) << 55) #define PTE_SPECIAL (_AT(pteval_t, 1) << 56) +#define PTE_DEVMAP (_AT(pteval_t, 1) << 57) #define PTE_PROT_NONE (_AT(pteval_t, 1) << 58) /* only when !PTE_VALID */ #ifndef __ASSEMBLY__ diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 2c41b04708fe..a6378625d47c 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -90,6 +90,7 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; #define pte_write(pte) (!!(pte_val(pte) & PTE_WRITE)) #define pte_user_exec(pte) (!(pte_val(pte) & PTE_UXN)) #define pte_cont(pte) (!!(pte_val(pte) & PTE_CONT)) +#define pte_devmap(pte) (!!(pte_val(pte) & PTE_DEVMAP)) #define pte_cont_addr_end(addr, end) \ ({ unsigned long __boundary = ((addr) + CONT_PTE_SIZE) & CONT_PTE_MASK; \ @@ -217,6 +218,11 @@ static inline pmd_t pmd_mkcont(pmd_t pmd) return __pmd(pmd_val(pmd) | PMD_SECT_CONT); } +static inline pte_t pte_mkdevmap(pte_t pte) +{ + return set_pte_bit(pte, __pgprot(PTE_DEVMAP)); +} + static inline void set_pte(pte_t *ptep, pte_t pte) { WRITE_ONCE(*ptep, pte); @@ -381,6 +387,9 @@ static inline int pmd_protnone(pmd_t pmd) #define pmd_mkhuge(pmd) (__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT)) +#define pmd_devmap(pmd) pte_devmap(pmd_pte(pmd)) +#define pmd_mkdevmap(pmd) pte_pmd(pte_mkdevmap(pmd_pte(pmd))) + #define __pmd_to_phys(pmd) __pte_to_phys(pmd_pte(pmd)) #define __phys_to_pmd_val(phys) __phys_to_pte_val(phys) #define pmd_pfn(pmd) ((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT) @@ -537,6 +546,11 @@ static inline phys_addr_t pud_page_paddr(pud_t pud) return __pud_to_phys(pud); } +static inline int pud_devmap(pud_t pud) +{ + return 0; +} + /* Find an entry in the second-level page table. */ #define pmd_index(addr) (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1)) @@ -624,6 +638,11 @@ static inline phys_addr_t pgd_page_paddr(pgd_t pgd) #define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd_val(pgd)) +static inline int pgd_devmap(pgd_t pgd) +{ + return 0; +} + /* to find an entry in a page-table-directory */ #define pgd_index(addr) (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
In order for things like get_user_pages() to work on ZONE_DEVICE memory, we need a software PTE bit to identify device-backed PFNs. Hook this up along with the relevant helpers to join in with ARCH_HAS_PTE_DEVMAP. Signed-off-by: Robin Murphy <robin.murphy@arm.com> --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/pgtable-prot.h | 1 + arch/arm64/include/asm/pgtable.h | 19 +++++++++++++++++++ 3 files changed, 21 insertions(+)