diff options
Diffstat (limited to 'arch/powerpc/include/asm/book3s/64/pgtable.h')
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/pgtable.h | 42 |
1 files changed, 37 insertions, 5 deletions
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h index 581f91be9dd4..ccf00a8b98c6 100644 --- a/arch/powerpc/include/asm/book3s/64/pgtable.h +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h @@ -277,9 +277,11 @@ extern unsigned long __vmalloc_end; extern unsigned long __kernel_virt_start; extern unsigned long __kernel_virt_size; extern unsigned long __kernel_io_start; +extern unsigned long __kernel_io_end; #define KERN_VIRT_START __kernel_virt_start -#define KERN_VIRT_SIZE __kernel_virt_size #define KERN_IO_START __kernel_io_start +#define KERN_IO_END __kernel_io_end + extern struct page *vmemmap; extern unsigned long ioremap_bot; extern unsigned long pci_io_base; @@ -296,8 +298,7 @@ extern unsigned long pci_io_base; #include <asm/barrier.h> /* - * The second half of the kernel virtual space is used for IO mappings, - * it's itself carved into the PIO region (ISA and PHB IO space) and + * IO space itself carved into the PIO region (ISA and PHB IO space) and * the ioremap space * * ISA_IO_BASE = KERN_IO_START, 64K reserved area @@ -310,7 +311,7 @@ extern unsigned long pci_io_base; #define PHB_IO_BASE (ISA_IO_END) #define PHB_IO_END (KERN_IO_START + FULL_IO_SIZE) #define IOREMAP_BASE (PHB_IO_END) -#define IOREMAP_END (KERN_VIRT_START + KERN_VIRT_SIZE) +#define IOREMAP_END (KERN_IO_END) /* Advertise special mapping type for AGP */ #define HAVE_PAGE_AGP @@ -875,6 +876,23 @@ static inline int pmd_present(pmd_t pmd) return false; } +static inline int pmd_is_serializing(pmd_t pmd) +{ + /* + * If the pmd is undergoing a split, the _PAGE_PRESENT bit is clear + * and _PAGE_INVALID is set (see pmd_present, pmdp_invalidate). + * + * This condition may also occur when flushing a pmd while flushing + * it (see ptep_modify_prot_start), so callers must ensure this + * case is fine as well. + */ + if ((pmd_raw(pmd) & cpu_to_be64(_PAGE_PRESENT | _PAGE_INVALID)) == + cpu_to_be64(_PAGE_INVALID)) + return true; + + return false; +} + static inline int pmd_bad(pmd_t pmd) { if (radix_enabled()) @@ -992,7 +1010,8 @@ extern struct page *pgd_page(pgd_t pgd); (((pte_t *) pmd_page_vaddr(*(dir))) + pte_index(addr)) #define pte_offset_map(dir,addr) pte_offset_kernel((dir), (addr)) -#define pte_unmap(pte) do { } while(0) + +static inline void pte_unmap(pte_t *pte) { } /* to find an entry in a kernel page-table-directory */ /* This now only contains the vmalloc pages */ @@ -1090,6 +1109,19 @@ static inline int pmd_protnone(pmd_t pmd) #define pmd_access_permitted pmd_access_permitted static inline bool pmd_access_permitted(pmd_t pmd, bool write) { + /* + * pmdp_invalidate sets this combination (which is not caught by + * !pte_present() check in pte_access_permitted), to prevent + * lock-free lookups, as part of the serialize_against_pte_lookup() + * synchronisation. + * + * This also catches the case where the PTE's hardware PRESENT bit is + * cleared while TLB is flushed, which is suboptimal but should not + * be frequent. + */ + if (pmd_is_serializing(pmd)) + return false; + return pte_access_permitted(pmd_pte(pmd), write); } |