diff options
| -rw-r--r-- | mm/Kconfig | 1 | ||||
| -rw-r--r-- | mm/Makefile | 4 | ||||
| -rw-r--r-- | mm/gup.c | 67 | ||||
| -rw-r--r-- | mm/nommu.c | 88 | ||||
| -rw-r--r-- | mm/util.c | 47 |
5 files changed, 65 insertions, 142 deletions
diff --git a/mm/Kconfig b/mm/Kconfig index b5a258d62465..48840b28482b 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -133,6 +133,7 @@ config HAVE_MEMBLOCK_PHYS_MAP bool config HAVE_FAST_GUP + depends on MMU bool config ARCH_KEEP_MEMBLOCK diff --git a/mm/Makefile b/mm/Makefile index ac5e5ba78874..dc0746ca1109 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -22,7 +22,7 @@ KCOV_INSTRUMENT_mmzone.o := n KCOV_INSTRUMENT_vmstat.o := n mmu-y := nommu.o -mmu-$(CONFIG_MMU) := gup.o highmem.o memory.o mincore.o \ +mmu-$(CONFIG_MMU) := highmem.o memory.o mincore.o \ mlock.o mmap.o mmu_gather.o mprotect.o mremap.o \ msync.o page_vma_mapped.o pagewalk.o \ pgtable-generic.o rmap.o vmalloc.o @@ -39,7 +39,7 @@ obj-y := filemap.o mempool.o oom_kill.o fadvise.o \ mm_init.o mmu_context.o percpu.o slab_common.o \ compaction.o vmacache.o \ interval_tree.o list_lru.o workingset.o \ - debug.o $(mmu-y) + debug.o gup.o $(mmu-y) # Give 'page_alloc' its own module-parameter namespace page-alloc-y := page_alloc.o @@ -134,6 +134,7 @@ void put_user_pages(struct page **pages, unsigned long npages) } EXPORT_SYMBOL(put_user_pages); +#ifdef CONFIG_MMU static struct page *no_page_table(struct vm_area_struct *vma, unsigned int flags) { @@ -1322,6 +1323,51 @@ struct page *get_dump_page(unsigned long addr) return page; } #endif /* CONFIG_ELF_CORE */ +#else /* CONFIG_MMU */ +static long __get_user_pages_locked(struct task_struct *tsk, + struct mm_struct *mm, unsigned long start, + unsigned long nr_pages, struct page **pages, + struct vm_area_struct **vmas, int *locked, + unsigned int foll_flags) +{ + struct vm_area_struct *vma; + unsigned long vm_flags; + int i; + + /* calculate required read or write permissions. + * If FOLL_FORCE is set, we only require the "MAY" flags. + */ + vm_flags = (foll_flags & FOLL_WRITE) ? + (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD); + vm_flags &= (foll_flags & FOLL_FORCE) ? + (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE); + + for (i = 0; i < nr_pages; i++) { + vma = find_vma(mm, start); + if (!vma) + goto finish_or_fault; + + /* protect what we can, including chardevs */ + if ((vma->vm_flags & (VM_IO | VM_PFNMAP)) || + !(vm_flags & vma->vm_flags)) + goto finish_or_fault; + + if (pages) { + pages[i] = virt_to_page(start); + if (pages[i]) + get_page(pages[i]); + } + if (vmas) + vmas[i] = vma; + start = (start + PAGE_SIZE) & PAGE_MASK; + } + + return i; + +finish_or_fault: + return i ? : -EFAULT; +} +#endif /* !CONFIG_MMU */ #if defined(CONFIG_FS_DAX) || defined (CONFIG_CMA) static bool check_dax_vmas(struct vm_area_struct **vmas, long nr_pages) @@ -1484,7 +1530,7 @@ static long check_and_migrate_cma_pages(struct task_struct *tsk, { return nr_pages; } -#endif +#endif /* CONFIG_CMA */ /* * __gup_longterm_locked() is a wrapper for __get_user_pages_locked which @@ -2160,6 +2206,12 @@ static void gup_pgd_range(unsigned long addr, unsigned long end, return; } while (pgdp++, addr = next, addr != end); } +#else +static inline void gup_pgd_range(unsigned long addr, unsigned long end, + unsigned int flags, struct page **pages, int *nr) +{ +} +#endif /* CONFIG_HAVE_FAST_GUP */ #ifndef gup_fast_permitted /* @@ -2177,6 +2229,9 @@ static bool gup_fast_permitted(unsigned long start, unsigned long end) * the regular GUP. * Note a difference with get_user_pages_fast: this always returns the * number of pages pinned, 0 if no pages were pinned. + * + * If the architecture does not support this function, simply return with no + * pages pinned. */ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, struct page **pages) @@ -2206,7 +2261,8 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, * block IPIs that come from THPs splitting. */ - if (gup_fast_permitted(start, end)) { + if (IS_ENABLED(CONFIG_HAVE_FAST_GUP) && + gup_fast_permitted(start, end)) { local_irq_save(flags); gup_pgd_range(start, end, write ? FOLL_WRITE : 0, pages, &nr); local_irq_restore(flags); @@ -2214,6 +2270,7 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, return nr; } +EXPORT_SYMBOL_GPL(__get_user_pages_fast); static int __gup_longterm_unlocked(unsigned long start, int nr_pages, unsigned int gup_flags, struct page **pages) @@ -2270,7 +2327,8 @@ int get_user_pages_fast(unsigned long start, int nr_pages, if (unlikely(!access_ok((void __user *)start, len))) return -EFAULT; - if (gup_fast_permitted(start, end)) { + if (IS_ENABLED(CONFIG_HAVE_FAST_GUP) && + gup_fast_permitted(start, end)) { local_irq_disable(); gup_pgd_range(addr, end, gup_flags, pages, &nr); local_irq_enable(); @@ -2296,5 +2354,4 @@ int get_user_pages_fast(unsigned long start, int nr_pages, return ret; } - -#endif /* CONFIG_HAVE_GENERIC_GUP */ +EXPORT_SYMBOL_GPL(get_user_pages_fast); diff --git a/mm/nommu.c b/mm/nommu.c index d8c02fbe03b5..07165ad2e548 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -111,94 +111,6 @@ unsigned int kobjsize(const void *objp) return PAGE_SIZE << compound_order(page); } -static long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, - unsigned long start, unsigned long nr_pages, - unsigned int foll_flags, struct page **pages, - struct vm_area_struct **vmas, int *nonblocking) -{ - struct vm_area_struct *vma; - unsigned long vm_flags; - int i; - - /* calculate required read or write permissions. - * If FOLL_FORCE is set, we only require the "MAY" flags. - */ - vm_flags = (foll_flags & FOLL_WRITE) ? - (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD); - vm_flags &= (foll_flags & FOLL_FORCE) ? - (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE); - - for (i = 0; i < nr_pages; i++) { - vma = find_vma(mm, start); - if (!vma) - goto finish_or_fault; - - /* protect what we can, including chardevs */ - if ((vma->vm_flags & (VM_IO | VM_PFNMAP)) || - !(vm_flags & vma->vm_flags)) - goto finish_or_fault; - - if (pages) { - pages[i] = virt_to_page(start); - if (pages[i]) - get_page(pages[i]); - } - if (vmas) - vmas[i] = vma; - start = (start + PAGE_SIZE) & PAGE_MASK; - } - - return i; - -finish_or_fault: - return i ? : -EFAULT; -} - -/* - * get a list of pages in an address range belonging to the specified process - * and indicate the VMA that covers each page - * - this is potentially dodgy as we may end incrementing the page count of a - * slab page or a secondary page from a compound page - * - don't permit access to VMAs that don't support it, such as I/O mappings - */ -long get_user_pages(unsigned long start, unsigned long nr_pages, - unsigned int gup_flags, struct page **pages, - struct vm_area_struct **vmas) -{ - return __get_user_pages(current, current->mm, start, nr_pages, - gup_flags, pages, vmas, NULL); -} -EXPORT_SYMBOL(get_user_pages); - -long get_user_pages_locked(unsigned long start, unsigned long nr_pages, - unsigned int gup_flags, struct page **pages, - int *locked) -{ - return get_user_pages(start, nr_pages, gup_flags, pages, NULL); -} -EXPORT_SYMBOL(get_user_pages_locked); - -static long __get_user_pages_unlocked(struct task_struct *tsk, - struct mm_struct *mm, unsigned long start, - unsigned long nr_pages, struct page **pages, - unsigned int gup_flags) -{ - long ret; - down_read(&mm->mmap_sem); - ret = __get_user_pages(tsk, mm, start, nr_pages, gup_flags, pages, - NULL, NULL); - up_read(&mm->mmap_sem); - return ret; -} - -long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages, - struct page **pages, unsigned int gup_flags) -{ - return __get_user_pages_unlocked(current, current->mm, start, nr_pages, - pages, gup_flags); -} -EXPORT_SYMBOL(get_user_pages_unlocked); - /** * follow_pfn - look up PFN at a user virtual address * @vma: memory mapping diff --git a/mm/util.c b/mm/util.c index 9834c4ab7d8e..68575a315dc5 100644 --- a/mm/util.c +++ b/mm/util.c @@ -300,53 +300,6 @@ void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) } #endif -/* - * Like get_user_pages_fast() except its IRQ-safe in that it won't fall - * back to the regular GUP. - * Note a difference with get_user_pages_fast: this always returns the - * number of pages pinned, 0 if no pages were pinned. - * If the architecture does not support this function, simply return with no - * pages pinned. - */ -int __weak __get_user_pages_fast(unsigned long start, - int nr_pages, int write, struct page **pages) -{ - return 0; -} -EXPORT_SYMBOL_GPL(__get_user_pages_fast); - -/** - * get_user_pages_fast() - pin user pages in memory - * @start: starting user address - * @nr_pages: number of pages from start to pin - * @gup_flags: flags modifying pin behaviour - * @pages: array that receives pointers to the pages pinned. - * Should be at least nr_pages long. - * - * get_user_pages_fast provides equivalent functionality to get_user_pages, - * operating on current and current->mm, with force=0 and vma=NULL. However - * unlike get_user_pages, it must be called without mmap_sem held. - * - * get_user_pages_fast may take mmap_sem and page table locks, so no - * assumptions can be made about lack of locking. get_user_pages_fast is to be - * implemented in a way that is advantageous (vs get_user_pages()) when the - * user memory area is already faulted in and present in ptes. However if the - * pages have to be faulted in, it may turn out to be slightly slower so - * callers need to carefully consider what to use. On many architectures, - * get_user_pages_fast simply falls back to get_user_pages. - * - * Return: number of pages pinned. This may be fewer than the number - * requested. If nr_pages is 0 or negative, returns 0. If no pages - * were pinned, returns -errno. - */ -int __weak get_user_pages_fast(unsigned long start, - int nr_pages, unsigned int gup_flags, - struct page **pages) -{ - return get_user_pages_unlocked(start, nr_pages, pages, gup_flags); -} -EXPORT_SYMBOL_GPL(get_user_pages_fast); - unsigned long vm_mmap_pgoff(struct file *file, unsigned long addr, unsigned long len, unsigned long prot, unsigned long flag, unsigned long pgoff) |