| Message ID | 20191007153822.16518-8-steven.price@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Generic page walk and ptdump | expand |
On 10/7/19 11:38 AM, Steven Price wrote: > walk_page_range() is going to be allowed to walk page tables other than > those of user space. For this it needs to know when it has reached a > 'leaf' entry in the page tables. This information is provided by the > p?d_leaf() functions/macros. > > For riscv a page is a leaf page when it has a read, write or execute bit > set on it. > > CC: Palmer Dabbelt <palmer@sifive.com> > CC: Albert Ou <aou@eecs.berkeley.edu> > CC: linux-riscv@lists.infradead.org > Signed-off-by: Steven Price <steven.price@arm.com> > --- > arch/riscv/include/asm/pgtable-64.h | 7 +++++++ > arch/riscv/include/asm/pgtable.h | 7 +++++++ > 2 files changed, 14 insertions(+) > > diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h > index 74630989006d..e88a8e8acbdf 100644 > --- a/arch/riscv/include/asm/pgtable-64.h > +++ b/arch/riscv/include/asm/pgtable-64.h > @@ -43,6 +43,13 @@ static inline int pud_bad(pud_t pud) > return !pud_present(pud); > } > > +#define pud_leaf pud_leaf > +static inline int pud_leaf(pud_t pud) > +{ > + return pud_present(pud) > + && (pud_val(pud) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC)); > +} > + > static inline void set_pud(pud_t *pudp, pud_t pud) > { > *pudp = pud; > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h > index 7255f2d8395b..b9a679153265 100644 > --- a/arch/riscv/include/asm/pgtable.h > +++ b/arch/riscv/include/asm/pgtable.h > @@ -130,6 +130,13 @@ static inline int pmd_bad(pmd_t pmd) > return !pmd_present(pmd); > } > > +#define pmd_leaf pmd_leaf > +static inline int pmd_leaf(pmd_t pmd) > +{ > + return pmd_present(pmd) > + && (pmd_val(pmd) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC)); > +} > + > static inline void set_pmd(pmd_t *pmdp, pmd_t pmd) > { > *pmdp = pmd; Hi Steven, The way you check leaf entries is correct: we do the same for hugepages. So is there a reason you did not use the pmd/pud_huge functions that are defined in arch/riscv/mm/hugetlbpage.c ? Anyway, FWIW: Reviewed-by: Alexandre Ghiti <alex@ghiti.fr> Thanks, Alex
On Mon, 7 Oct 2019, Steven Price wrote: > walk_page_range() is going to be allowed to walk page tables other than > those of user space. For this it needs to know when it has reached a > 'leaf' entry in the page tables. This information is provided by the > p?d_leaf() functions/macros. > > For riscv a page is a leaf page when it has a read, write or execute bit > set on it. > > CC: Palmer Dabbelt <palmer@sifive.com> > CC: Albert Ou <aou@eecs.berkeley.edu> > CC: linux-riscv@lists.infradead.org > Signed-off-by: Steven Price <steven.price@arm.com> Acked-by: Paul Walmsley <paul.walmsley@sifive.com> # for arch/riscv Alex has a good point, but probably the right thing to do is to replace the contents of the arch/riscv/mm/hugetlbpage.c p{u,m}d_huge() functions with calls to Steven's new static inline functions. - Paul
On 08/10/2019 22:33, Paul Walmsley wrote: > On Mon, 7 Oct 2019, Steven Price wrote: > >> walk_page_range() is going to be allowed to walk page tables other than >> those of user space. For this it needs to know when it has reached a >> 'leaf' entry in the page tables. This information is provided by the >> p?d_leaf() functions/macros. >> >> For riscv a page is a leaf page when it has a read, write or execute bit >> set on it. >> >> CC: Palmer Dabbelt <palmer@sifive.com> >> CC: Albert Ou <aou@eecs.berkeley.edu> >> CC: linux-riscv@lists.infradead.org >> Signed-off-by: Steven Price <steven.price@arm.com> > > Acked-by: Paul Walmsley <paul.walmsley@sifive.com> # for arch/riscv > > Alex has a good point, but probably the right thing to do is to replace > the contents of the arch/riscv/mm/hugetlbpage.c p{u,m}d_huge() functions > with calls to Steven's new static inline functions. The intention is to create new functions that are not dependent on hugepage support in user space. hugetlbpage.c is only built if CONFIG_HUGETLB_PAGE is defined. As you say - the p{u,m}d_huge() functions can be reimplemented using the new static inline functions if desired. Thanks for the review. Steve > > - Paul > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >
diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h index 74630989006d..e88a8e8acbdf 100644 --- a/arch/riscv/include/asm/pgtable-64.h +++ b/arch/riscv/include/asm/pgtable-64.h @@ -43,6 +43,13 @@ static inline int pud_bad(pud_t pud) return !pud_present(pud); } +#define pud_leaf pud_leaf +static inline int pud_leaf(pud_t pud) +{ + return pud_present(pud) + && (pud_val(pud) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC)); +} + static inline void set_pud(pud_t *pudp, pud_t pud) { *pudp = pud; diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index 7255f2d8395b..b9a679153265 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -130,6 +130,13 @@ static inline int pmd_bad(pmd_t pmd) return !pmd_present(pmd); } +#define pmd_leaf pmd_leaf +static inline int pmd_leaf(pmd_t pmd) +{ + return pmd_present(pmd) + && (pmd_val(pmd) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC)); +} + static inline void set_pmd(pmd_t *pmdp, pmd_t pmd) { *pmdp = pmd;
walk_page_range() is going to be allowed to walk page tables other than those of user space. For this it needs to know when it has reached a 'leaf' entry in the page tables. This information is provided by the p?d_leaf() functions/macros. For riscv a page is a leaf page when it has a read, write or execute bit set on it. CC: Palmer Dabbelt <palmer@sifive.com> CC: Albert Ou <aou@eecs.berkeley.edu> CC: linux-riscv@lists.infradead.org Signed-off-by: Steven Price <steven.price@arm.com> --- arch/riscv/include/asm/pgtable-64.h | 7 +++++++ arch/riscv/include/asm/pgtable.h | 7 +++++++ 2 files changed, 14 insertions(+)