| Message ID | 3ca4b53f5bcf016d98c875e22cd9cf02a3495f3e.1433927458.git.mchehab@osg.samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed 10-06-15 09:37:20, Josh Triplett wrote: > On Wed, Jun 10, 2015 at 06:20:52AM -0300, Mauro Carvalho Chehab wrote: > > From: Jan Kara <jack@suse.cz> > > > > get_vaddr_frames() is used by relatively rare drivers so hide it and the > > related functions behind a config option that is selected only by > > drivers that need the infrastructure. > > > > Suggested-by: Andrew Morton <akpm@linux-foundation.org> > > > > Signed-off-by: Jan Kara <jack@suse.cz> > > Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> > > Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com> > > Seems sensible to me. > > Since this patch makes the kernel smaller, can you include the delta > from bloat-o-meter between allnoconfig with and without this patch? The results are: add/remove: 0/6 grow/shrink: 0/0 up/down: 0/-868 (-868) function old new delta frame_vector_destroy 55 - -55 frame_vector_to_pfns 56 - -56 frame_vector_create 81 - -81 put_vaddr_frames 93 - -93 frame_vector_to_pages 98 - -98 get_vaddr_frames 485 - -485 I've added it to the changelog of the patch. > Also, I assume you've compile-tested the kernel with allyesconfig minus > the three options that now have "select FRAME_VECTOR", to make sure it > builds? I did not because the config option VIDEOBUF2_MEMOPS is a virtual one selected transitively by quite a few video drivers and I didn't bother with tracking down all of them... But since that config option guards compilation of the code I modified I'm pretty confident I got it right. Honza > > create mode 100644 mm/frame_vector.c > > > > diff --git a/drivers/gpu/drm/exynos/Kconfig b/drivers/gpu/drm/exynos/Kconfig > > index 0a6780367d28..fc678289cf79 100644 > > --- a/drivers/gpu/drm/exynos/Kconfig > > +++ b/drivers/gpu/drm/exynos/Kconfig > > @@ -71,6 +71,7 @@ config DRM_EXYNOS_VIDI > > config DRM_EXYNOS_G2D > > bool "Exynos DRM G2D" > > depends on DRM_EXYNOS && !VIDEO_SAMSUNG_S5P_G2D > > + select FRAME_VECTOR > > help > > Choose this option if you want to use Exynos G2D for DRM. > > > > diff --git a/drivers/media/platform/omap/Kconfig b/drivers/media/platform/omap/Kconfig > > index dc2aaab54aef..217d613b0fe7 100644 > > --- a/drivers/media/platform/omap/Kconfig > > +++ b/drivers/media/platform/omap/Kconfig > > @@ -10,6 +10,7 @@ config VIDEO_OMAP2_VOUT > > select OMAP2_DSS if HAS_IOMEM && ARCH_OMAP2PLUS > > select OMAP2_VRFB if ARCH_OMAP2 || ARCH_OMAP3 > > select VIDEO_OMAP2_VOUT_VRFB if VIDEO_OMAP2_VOUT && OMAP2_VRFB > > + select FRAME_VECTOR > > default n > > ---help--- > > V4L2 Display driver support for OMAP2/3 based boards. > > diff --git a/drivers/media/v4l2-core/Kconfig b/drivers/media/v4l2-core/Kconfig > > index f7a01a72eb9e..f38f6e387f04 100644 > > --- a/drivers/media/v4l2-core/Kconfig > > +++ b/drivers/media/v4l2-core/Kconfig > > @@ -73,6 +73,7 @@ config VIDEOBUF2_CORE > > > > config VIDEOBUF2_MEMOPS > > tristate > > + select FRAME_VECTOR > > > > config VIDEOBUF2_DMA_CONTIG > > tristate > > diff --git a/mm/Kconfig b/mm/Kconfig > > index 390214da4546..2ca52e9986f0 100644 > > --- a/mm/Kconfig > > +++ b/mm/Kconfig > > @@ -635,3 +635,6 @@ config MAX_STACK_SIZE_MB > > changed to a smaller value in which case that is used. > > > > A sane initial value is 80 MB. > > + > > +config FRAME_VECTOR > > + bool > > diff --git a/mm/Makefile b/mm/Makefile > > index 98c4eaeabdcb..be5d5c866305 100644 > > --- a/mm/Makefile > > +++ b/mm/Makefile > > @@ -78,3 +78,4 @@ obj-$(CONFIG_CMA) += cma.o > > obj-$(CONFIG_MEMORY_BALLOON) += balloon_compaction.o > > obj-$(CONFIG_PAGE_EXTENSION) += page_ext.o > > obj-$(CONFIG_CMA_DEBUGFS) += cma_debug.o > > +obj-$(CONFIG_FRAME_VECTOR) += frame_vector.o > > diff --git a/mm/frame_vector.c b/mm/frame_vector.c > > new file mode 100644 > > index 000000000000..31a2bd5f41d5 > > --- /dev/null > > +++ b/mm/frame_vector.c > > @@ -0,0 +1,232 @@ > > +#include <linux/kernel.h> > > +#include <linux/errno.h> > > +#include <linux/err.h> > > +#include <linux/mm.h> > > +#include <linux/slab.h> > > +#include <linux/pagemap.h> > > +#include <linux/sched.h> > > + > > +/* > > + * get_vaddr_frames() - map virtual addresses to pfns > > + * @start: starting user address > > + * @nr_frames: number of pages / pfns from start to map > > + * @write: whether pages will be written to by the caller > > + * @force: whether to force write access even if user mapping is > > + * readonly. See description of the same argument of > > + get_user_pages(). > > + * @vec: structure which receives pages / pfns of the addresses mapped. > > + * It should have space for at least nr_frames entries. > > + * > > + * This function maps virtual addresses from @start and fills @vec structure > > + * with page frame numbers or page pointers to corresponding pages (choice > > + * depends on the type of the vma underlying the virtual address). If @start > > + * belongs to a normal vma, the function grabs reference to each of the pages > > + * to pin them in memory. If @start belongs to VM_IO | VM_PFNMAP vma, we don't > > + * touch page structures and the caller must make sure pfns aren't reused for > > + * anything else while he is using them. > > + * > > + * The function returns number of pages mapped which may be less than > > + * @nr_frames. In particular we stop mapping if there are more vmas of > > + * different type underlying the specified range of virtual addresses. > > + * When the function isn't able to map a single page, it returns error. > > + * > > + * This function takes care of grabbing mmap_sem as necessary. > > + */ > > +int get_vaddr_frames(unsigned long start, unsigned int nr_frames, > > + bool write, bool force, struct frame_vector *vec) > > +{ > > + struct mm_struct *mm = current->mm; > > + struct vm_area_struct *vma; > > + int ret = 0; > > + int err; > > + int locked; > > + > > + if (nr_frames == 0) > > + return 0; > > + > > + if (WARN_ON_ONCE(nr_frames > vec->nr_allocated)) > > + nr_frames = vec->nr_allocated; > > + > > + down_read(&mm->mmap_sem); > > + locked = 1; > > + vma = find_vma_intersection(mm, start, start + 1); > > + if (!vma) { > > + ret = -EFAULT; > > + goto out; > > + } > > + if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) { > > + vec->got_ref = true; > > + vec->is_pfns = false; > > + ret = get_user_pages_locked(current, mm, start, nr_frames, > > + write, force, (struct page **)(vec->ptrs), &locked); > > + goto out; > > + } > > + > > + vec->got_ref = false; > > + vec->is_pfns = true; > > + do { > > + unsigned long *nums = frame_vector_pfns(vec); > > + > > + while (ret < nr_frames && start + PAGE_SIZE <= vma->vm_end) { > > + err = follow_pfn(vma, start, &nums[ret]); > > + if (err) { > > + if (ret == 0) > > + ret = err; > > + goto out; > > + } > > + start += PAGE_SIZE; > > + ret++; > > + } > > + /* > > + * We stop if we have enough pages or if VMA doesn't completely > > + * cover the tail page. > > + */ > > + if (ret >= nr_frames || start < vma->vm_end) > > + break; > > + vma = find_vma_intersection(mm, start, start + 1); > > + } while (vma && vma->vm_flags & (VM_IO | VM_PFNMAP)); > > +out: > > + if (locked) > > + up_read(&mm->mmap_sem); > > + if (!ret) > > + ret = -EFAULT; > > + if (ret > 0) > > + vec->nr_frames = ret; > > + return ret; > > +} > > +EXPORT_SYMBOL(get_vaddr_frames); > > + > > +/** > > + * put_vaddr_frames() - drop references to pages if get_vaddr_frames() acquired > > + * them > > + * @vec: frame vector to put > > + * > > + * Drop references to pages if get_vaddr_frames() acquired them. We also > > + * invalidate the frame vector so that it is prepared for the next call into > > + * get_vaddr_frames(). > > + */ > > +void put_vaddr_frames(struct frame_vector *vec) > > +{ > > + int i; > > + struct page **pages; > > + > > + if (!vec->got_ref) > > + goto out; > > + pages = frame_vector_pages(vec); > > + /* > > + * frame_vector_pages() might needed to do a conversion when > > + * get_vaddr_frames() got pages but vec was later converted to pfns. > > + * But it shouldn't really fail to convert pfns back... > > + */ > > + if (WARN_ON(IS_ERR(pages))) > > + goto out; > > + for (i = 0; i < vec->nr_frames; i++) > > + put_page(pages[i]); > > + vec->got_ref = false; > > +out: > > + vec->nr_frames = 0; > > +} > > +EXPORT_SYMBOL(put_vaddr_frames); > > + > > +/** > > + * frame_vector_to_pages - convert frame vector to contain page pointers > > + * @vec: frame vector to convert > > + * > > + * Convert @vec to contain array of page pointers. If the conversion is > > + * successful, return 0. Otherwise return an error. Note that we do not grab > > + * page references for the page structures. > > + */ > > +int frame_vector_to_pages(struct frame_vector *vec) > > +{ > > + int i; > > + unsigned long *nums; > > + struct page **pages; > > + > > + if (!vec->is_pfns) > > + return 0; > > + nums = frame_vector_pfns(vec); > > + for (i = 0; i < vec->nr_frames; i++) > > + if (!pfn_valid(nums[i])) > > + return -EINVAL; > > + pages = (struct page **)nums; > > + for (i = 0; i < vec->nr_frames; i++) > > + pages[i] = pfn_to_page(nums[i]); > > + vec->is_pfns = false; > > + return 0; > > +} > > +EXPORT_SYMBOL(frame_vector_to_pages); > > + > > +/** > > + * frame_vector_to_pfns - convert frame vector to contain pfns > > + * @vec: frame vector to convert > > + * > > + * Convert @vec to contain array of pfns. > > + */ > > +void frame_vector_to_pfns(struct frame_vector *vec) > > +{ > > + int i; > > + unsigned long *nums; > > + struct page **pages; > > + > > + if (vec->is_pfns) > > + return; > > + pages = (struct page **)(vec->ptrs); > > + nums = (unsigned long *)pages; > > + for (i = 0; i < vec->nr_frames; i++) > > + nums[i] = page_to_pfn(pages[i]); > > + vec->is_pfns = true; > > +} > > +EXPORT_SYMBOL(frame_vector_to_pfns); > > + > > +/** > > + * frame_vector_create() - allocate & initialize structure for pinned pfns > > + * @nr_frames: number of pfns slots we should reserve > > + * > > + * Allocate and initialize struct pinned_pfns to be able to hold @nr_pfns > > + * pfns. > > + */ > > +struct frame_vector *frame_vector_create(unsigned int nr_frames) > > +{ > > + struct frame_vector *vec; > > + int size = sizeof(struct frame_vector) + sizeof(void *) * nr_frames; > > + > > + if (WARN_ON_ONCE(nr_frames == 0)) > > + return NULL; > > + /* > > + * This is absurdly high. It's here just to avoid strange effects when > > + * arithmetics overflows. > > + */ > > + if (WARN_ON_ONCE(nr_frames > INT_MAX / sizeof(void *) / 2)) > > + return NULL; > > + /* > > + * Avoid higher order allocations, use vmalloc instead. It should > > + * be rare anyway. > > + */ > > + if (size <= PAGE_SIZE) > > + vec = kmalloc(size, GFP_KERNEL); > > + else > > + vec = vmalloc(size); > > + if (!vec) > > + return NULL; > > + vec->nr_allocated = nr_frames; > > + vec->nr_frames = 0; > > + return vec; > > +} > > +EXPORT_SYMBOL(frame_vector_create); > > + > > +/** > > + * frame_vector_destroy() - free memory allocated to carry frame vector > > + * @vec: Frame vector to free > > + * > > + * Free structure allocated by frame_vector_create() to carry frames. > > + */ > > +void frame_vector_destroy(struct frame_vector *vec) > > +{ > > + /* Make sure put_vaddr_frames() got called properly... */ > > + VM_BUG_ON(vec->nr_frames > 0); > > + if (!is_vmalloc_addr(vec)) > > + kfree(vec); > > + else > > + vfree(vec); > > +} > > +EXPORT_SYMBOL(frame_vector_destroy); > > diff --git a/mm/gup.c b/mm/gup.c > > index 9d7f4fde30cb..222d57e335f9 100644 > > --- a/mm/gup.c > > +++ b/mm/gup.c > > @@ -937,231 +937,6 @@ int __mm_populate(unsigned long start, unsigned long len, int ignore_errors) > > return ret; /* 0 or negative error code */ > > } > > > > -/* > > - * get_vaddr_frames() - map virtual addresses to pfns > > - * @start: starting user address > > - * @nr_frames: number of pages / pfns from start to map > > - * @write: whether pages will be written to by the caller > > - * @force: whether to force write access even if user mapping is > > - * readonly. See description of the same argument of > > - get_user_pages(). > > - * @vec: structure which receives pages / pfns of the addresses mapped. > > - * It should have space for at least nr_frames entries. > > - * > > - * This function maps virtual addresses from @start and fills @vec structure > > - * with page frame numbers or page pointers to corresponding pages (choice > > - * depends on the type of the vma underlying the virtual address). If @start > > - * belongs to a normal vma, the function grabs reference to each of the pages > > - * to pin them in memory. If @start belongs to VM_IO | VM_PFNMAP vma, we don't > > - * touch page structures and the caller must make sure pfns aren't reused for > > - * anything else while he is using them. > > - * > > - * The function returns number of pages mapped which may be less than > > - * @nr_frames. In particular we stop mapping if there are more vmas of > > - * different type underlying the specified range of virtual addresses. > > - * When the function isn't able to map a single page, it returns error. > > - * > > - * This function takes care of grabbing mmap_sem as necessary. > > - */ > > -int get_vaddr_frames(unsigned long start, unsigned int nr_frames, > > - bool write, bool force, struct frame_vector *vec) > > -{ > > - struct mm_struct *mm = current->mm; > > - struct vm_area_struct *vma; > > - int ret = 0; > > - int err; > > - int locked; > > - > > - if (nr_frames == 0) > > - return 0; > > - > > - if (WARN_ON_ONCE(nr_frames > vec->nr_allocated)) > > - nr_frames = vec->nr_allocated; > > - > > - down_read(&mm->mmap_sem); > > - locked = 1; > > - vma = find_vma_intersection(mm, start, start + 1); > > - if (!vma) { > > - ret = -EFAULT; > > - goto out; > > - } > > - if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) { > > - vec->got_ref = true; > > - vec->is_pfns = false; > > - ret = get_user_pages_locked(current, mm, start, nr_frames, > > - write, force, (struct page **)(vec->ptrs), &locked); > > - goto out; > > - } > > - > > - vec->got_ref = false; > > - vec->is_pfns = true; > > - do { > > - unsigned long *nums = frame_vector_pfns(vec); > > - > > - while (ret < nr_frames && start + PAGE_SIZE <= vma->vm_end) { > > - err = follow_pfn(vma, start, &nums[ret]); > > - if (err) { > > - if (ret == 0) > > - ret = err; > > - goto out; > > - } > > - start += PAGE_SIZE; > > - ret++; > > - } > > - /* > > - * We stop if we have enough pages or if VMA doesn't completely > > - * cover the tail page. > > - */ > > - if (ret >= nr_frames || start < vma->vm_end) > > - break; > > - vma = find_vma_intersection(mm, start, start + 1); > > - } while (vma && vma->vm_flags & (VM_IO | VM_PFNMAP)); > > -out: > > - if (locked) > > - up_read(&mm->mmap_sem); > > - if (!ret) > > - ret = -EFAULT; > > - if (ret > 0) > > - vec->nr_frames = ret; > > - return ret; > > -} > > -EXPORT_SYMBOL(get_vaddr_frames); > > - > > -/** > > - * put_vaddr_frames() - drop references to pages if get_vaddr_frames() acquired > > - * them > > - * @vec: frame vector to put > > - * > > - * Drop references to pages if get_vaddr_frames() acquired them. We also > > - * invalidate the frame vector so that it is prepared for the next call into > > - * get_vaddr_frames(). > > - */ > > -void put_vaddr_frames(struct frame_vector *vec) > > -{ > > - int i; > > - struct page **pages; > > - > > - if (!vec->got_ref) > > - goto out; > > - pages = frame_vector_pages(vec); > > - /* > > - * frame_vector_pages() might needed to do a conversion when > > - * get_vaddr_frames() got pages but vec was later converted to pfns. > > - * But it shouldn't really fail to convert pfns back... > > - */ > > - if (WARN_ON(IS_ERR(pages))) > > - goto out; > > - for (i = 0; i < vec->nr_frames; i++) > > - put_page(pages[i]); > > - vec->got_ref = false; > > -out: > > - vec->nr_frames = 0; > > -} > > -EXPORT_SYMBOL(put_vaddr_frames); > > - > > -/** > > - * frame_vector_to_pages - convert frame vector to contain page pointers > > - * @vec: frame vector to convert > > - * > > - * Convert @vec to contain array of page pointers. If the conversion is > > - * successful, return 0. Otherwise return an error. Note that we do not grab > > - * page references for the page structures. > > - */ > > -int frame_vector_to_pages(struct frame_vector *vec) > > -{ > > - int i; > > - unsigned long *nums; > > - struct page **pages; > > - > > - if (!vec->is_pfns) > > - return 0; > > - nums = frame_vector_pfns(vec); > > - for (i = 0; i < vec->nr_frames; i++) > > - if (!pfn_valid(nums[i])) > > - return -EINVAL; > > - pages = (struct page **)nums; > > - for (i = 0; i < vec->nr_frames; i++) > > - pages[i] = pfn_to_page(nums[i]); > > - vec->is_pfns = false; > > - return 0; > > -} > > -EXPORT_SYMBOL(frame_vector_to_pages); > > - > > -/** > > - * frame_vector_to_pfns - convert frame vector to contain pfns > > - * @vec: frame vector to convert > > - * > > - * Convert @vec to contain array of pfns. > > - */ > > -void frame_vector_to_pfns(struct frame_vector *vec) > > -{ > > - int i; > > - unsigned long *nums; > > - struct page **pages; > > - > > - if (vec->is_pfns) > > - return; > > - pages = (struct page **)(vec->ptrs); > > - nums = (unsigned long *)pages; > > - for (i = 0; i < vec->nr_frames; i++) > > - nums[i] = page_to_pfn(pages[i]); > > - vec->is_pfns = true; > > -} > > -EXPORT_SYMBOL(frame_vector_to_pfns); > > - > > -/** > > - * frame_vector_create() - allocate & initialize structure for pinned pfns > > - * @nr_frames: number of pfns slots we should reserve > > - * > > - * Allocate and initialize struct pinned_pfns to be able to hold @nr_pfns > > - * pfns. > > - */ > > -struct frame_vector *frame_vector_create(unsigned int nr_frames) > > -{ > > - struct frame_vector *vec; > > - int size = sizeof(struct frame_vector) + sizeof(void *) * nr_frames; > > - > > - if (WARN_ON_ONCE(nr_frames == 0)) > > - return NULL; > > - /* > > - * This is absurdly high. It's here just to avoid strange effects when > > - * arithmetics overflows. > > - */ > > - if (WARN_ON_ONCE(nr_frames > INT_MAX / sizeof(void *) / 2)) > > - return NULL; > > - /* > > - * Avoid higher order allocations, use vmalloc instead. It should > > - * be rare anyway. > > - */ > > - if (size <= PAGE_SIZE) > > - vec = kmalloc(size, GFP_KERNEL); > > - else > > - vec = vmalloc(size); > > - if (!vec) > > - return NULL; > > - vec->nr_allocated = nr_frames; > > - vec->nr_frames = 0; > > - return vec; > > -} > > -EXPORT_SYMBOL(frame_vector_create); > > - > > -/** > > - * frame_vector_destroy() - free memory allocated to carry frame vector > > - * @vec: Frame vector to free > > - * > > - * Free structure allocated by frame_vector_create() to carry frames. > > - */ > > -void frame_vector_destroy(struct frame_vector *vec) > > -{ > > - /* Make sure put_vaddr_frames() got called properly... */ > > - VM_BUG_ON(vec->nr_frames > 0); > > - if (!is_vmalloc_addr(vec)) > > - kfree(vec); > > - else > > - vfree(vec); > > -} > > -EXPORT_SYMBOL(frame_vector_destroy); > > - > > /** > > * get_dump_page() - pin user page in memory while writing it to core dump > > * @addr: user address > > -- > > 2.4.2 > >
diff --git a/drivers/gpu/drm/exynos/Kconfig b/drivers/gpu/drm/exynos/Kconfig index 0a6780367d28..fc678289cf79 100644 --- a/drivers/gpu/drm/exynos/Kconfig +++ b/drivers/gpu/drm/exynos/Kconfig @@ -71,6 +71,7 @@ config DRM_EXYNOS_VIDI config DRM_EXYNOS_G2D bool "Exynos DRM G2D" depends on DRM_EXYNOS && !VIDEO_SAMSUNG_S5P_G2D + select FRAME_VECTOR help Choose this option if you want to use Exynos G2D for DRM. diff --git a/drivers/media/platform/omap/Kconfig b/drivers/media/platform/omap/Kconfig index dc2aaab54aef..217d613b0fe7 100644 --- a/drivers/media/platform/omap/Kconfig +++ b/drivers/media/platform/omap/Kconfig @@ -10,6 +10,7 @@ config VIDEO_OMAP2_VOUT select OMAP2_DSS if HAS_IOMEM && ARCH_OMAP2PLUS select OMAP2_VRFB if ARCH_OMAP2 || ARCH_OMAP3 select VIDEO_OMAP2_VOUT_VRFB if VIDEO_OMAP2_VOUT && OMAP2_VRFB + select FRAME_VECTOR default n ---help--- V4L2 Display driver support for OMAP2/3 based boards. diff --git a/drivers/media/v4l2-core/Kconfig b/drivers/media/v4l2-core/Kconfig index f7a01a72eb9e..f38f6e387f04 100644 --- a/drivers/media/v4l2-core/Kconfig +++ b/drivers/media/v4l2-core/Kconfig @@ -73,6 +73,7 @@ config VIDEOBUF2_CORE config VIDEOBUF2_MEMOPS tristate + select FRAME_VECTOR config VIDEOBUF2_DMA_CONTIG tristate diff --git a/mm/Kconfig b/mm/Kconfig index 390214da4546..2ca52e9986f0 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -635,3 +635,6 @@ config MAX_STACK_SIZE_MB changed to a smaller value in which case that is used. A sane initial value is 80 MB. + +config FRAME_VECTOR + bool diff --git a/mm/Makefile b/mm/Makefile index 98c4eaeabdcb..be5d5c866305 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -78,3 +78,4 @@ obj-$(CONFIG_CMA) += cma.o obj-$(CONFIG_MEMORY_BALLOON) += balloon_compaction.o obj-$(CONFIG_PAGE_EXTENSION) += page_ext.o obj-$(CONFIG_CMA_DEBUGFS) += cma_debug.o +obj-$(CONFIG_FRAME_VECTOR) += frame_vector.o diff --git a/mm/frame_vector.c b/mm/frame_vector.c new file mode 100644 index 000000000000..31a2bd5f41d5 --- /dev/null +++ b/mm/frame_vector.c @@ -0,0 +1,232 @@ +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/pagemap.h> +#include <linux/sched.h> + +/* + * get_vaddr_frames() - map virtual addresses to pfns + * @start: starting user address + * @nr_frames: number of pages / pfns from start to map + * @write: whether pages will be written to by the caller + * @force: whether to force write access even if user mapping is + * readonly. See description of the same argument of + get_user_pages(). + * @vec: structure which receives pages / pfns of the addresses mapped. + * It should have space for at least nr_frames entries. + * + * This function maps virtual addresses from @start and fills @vec structure + * with page frame numbers or page pointers to corresponding pages (choice + * depends on the type of the vma underlying the virtual address). If @start + * belongs to a normal vma, the function grabs reference to each of the pages + * to pin them in memory. If @start belongs to VM_IO | VM_PFNMAP vma, we don't + * touch page structures and the caller must make sure pfns aren't reused for + * anything else while he is using them. + * + * The function returns number of pages mapped which may be less than + * @nr_frames. In particular we stop mapping if there are more vmas of + * different type underlying the specified range of virtual addresses. + * When the function isn't able to map a single page, it returns error. + * + * This function takes care of grabbing mmap_sem as necessary. + */ +int get_vaddr_frames(unsigned long start, unsigned int nr_frames, + bool write, bool force, struct frame_vector *vec) +{ + struct mm_struct *mm = current->mm; + struct vm_area_struct *vma; + int ret = 0; + int err; + int locked; + + if (nr_frames == 0) + return 0; + + if (WARN_ON_ONCE(nr_frames > vec->nr_allocated)) + nr_frames = vec->nr_allocated; + + down_read(&mm->mmap_sem); + locked = 1; + vma = find_vma_intersection(mm, start, start + 1); + if (!vma) { + ret = -EFAULT; + goto out; + } + if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) { + vec->got_ref = true; + vec->is_pfns = false; + ret = get_user_pages_locked(current, mm, start, nr_frames, + write, force, (struct page **)(vec->ptrs), &locked); + goto out; + } + + vec->got_ref = false; + vec->is_pfns = true; + do { + unsigned long *nums = frame_vector_pfns(vec); + + while (ret < nr_frames && start + PAGE_SIZE <= vma->vm_end) { + err = follow_pfn(vma, start, &nums[ret]); + if (err) { + if (ret == 0) + ret = err; + goto out; + } + start += PAGE_SIZE; + ret++; + } + /* + * We stop if we have enough pages or if VMA doesn't completely + * cover the tail page. + */ + if (ret >= nr_frames || start < vma->vm_end) + break; + vma = find_vma_intersection(mm, start, start + 1); + } while (vma && vma->vm_flags & (VM_IO | VM_PFNMAP)); +out: + if (locked) + up_read(&mm->mmap_sem); + if (!ret) + ret = -EFAULT; + if (ret > 0) + vec->nr_frames = ret; + return ret; +} +EXPORT_SYMBOL(get_vaddr_frames); + +/** + * put_vaddr_frames() - drop references to pages if get_vaddr_frames() acquired + * them + * @vec: frame vector to put + * + * Drop references to pages if get_vaddr_frames() acquired them. We also + * invalidate the frame vector so that it is prepared for the next call into + * get_vaddr_frames(). + */ +void put_vaddr_frames(struct frame_vector *vec) +{ + int i; + struct page **pages; + + if (!vec->got_ref) + goto out; + pages = frame_vector_pages(vec); + /* + * frame_vector_pages() might needed to do a conversion when + * get_vaddr_frames() got pages but vec was later converted to pfns. + * But it shouldn't really fail to convert pfns back... + */ + if (WARN_ON(IS_ERR(pages))) + goto out; + for (i = 0; i < vec->nr_frames; i++) + put_page(pages[i]); + vec->got_ref = false; +out: + vec->nr_frames = 0; +} +EXPORT_SYMBOL(put_vaddr_frames); + +/** + * frame_vector_to_pages - convert frame vector to contain page pointers + * @vec: frame vector to convert + * + * Convert @vec to contain array of page pointers. If the conversion is + * successful, return 0. Otherwise return an error. Note that we do not grab + * page references for the page structures. + */ +int frame_vector_to_pages(struct frame_vector *vec) +{ + int i; + unsigned long *nums; + struct page **pages; + + if (!vec->is_pfns) + return 0; + nums = frame_vector_pfns(vec); + for (i = 0; i < vec->nr_frames; i++) + if (!pfn_valid(nums[i])) + return -EINVAL; + pages = (struct page **)nums; + for (i = 0; i < vec->nr_frames; i++) + pages[i] = pfn_to_page(nums[i]); + vec->is_pfns = false; + return 0; +} +EXPORT_SYMBOL(frame_vector_to_pages); + +/** + * frame_vector_to_pfns - convert frame vector to contain pfns + * @vec: frame vector to convert + * + * Convert @vec to contain array of pfns. + */ +void frame_vector_to_pfns(struct frame_vector *vec) +{ + int i; + unsigned long *nums; + struct page **pages; + + if (vec->is_pfns) + return; + pages = (struct page **)(vec->ptrs); + nums = (unsigned long *)pages; + for (i = 0; i < vec->nr_frames; i++) + nums[i] = page_to_pfn(pages[i]); + vec->is_pfns = true; +} +EXPORT_SYMBOL(frame_vector_to_pfns); + +/** + * frame_vector_create() - allocate & initialize structure for pinned pfns + * @nr_frames: number of pfns slots we should reserve + * + * Allocate and initialize struct pinned_pfns to be able to hold @nr_pfns + * pfns. + */ +struct frame_vector *frame_vector_create(unsigned int nr_frames) +{ + struct frame_vector *vec; + int size = sizeof(struct frame_vector) + sizeof(void *) * nr_frames; + + if (WARN_ON_ONCE(nr_frames == 0)) + return NULL; + /* + * This is absurdly high. It's here just to avoid strange effects when + * arithmetics overflows. + */ + if (WARN_ON_ONCE(nr_frames > INT_MAX / sizeof(void *) / 2)) + return NULL; + /* + * Avoid higher order allocations, use vmalloc instead. It should + * be rare anyway. + */ + if (size <= PAGE_SIZE) + vec = kmalloc(size, GFP_KERNEL); + else + vec = vmalloc(size); + if (!vec) + return NULL; + vec->nr_allocated = nr_frames; + vec->nr_frames = 0; + return vec; +} +EXPORT_SYMBOL(frame_vector_create); + +/** + * frame_vector_destroy() - free memory allocated to carry frame vector + * @vec: Frame vector to free + * + * Free structure allocated by frame_vector_create() to carry frames. + */ +void frame_vector_destroy(struct frame_vector *vec) +{ + /* Make sure put_vaddr_frames() got called properly... */ + VM_BUG_ON(vec->nr_frames > 0); + if (!is_vmalloc_addr(vec)) + kfree(vec); + else + vfree(vec); +} +EXPORT_SYMBOL(frame_vector_destroy); diff --git a/mm/gup.c b/mm/gup.c index 9d7f4fde30cb..222d57e335f9 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -937,231 +937,6 @@ int __mm_populate(unsigned long start, unsigned long len, int ignore_errors) return ret; /* 0 or negative error code */ } -/* - * get_vaddr_frames() - map virtual addresses to pfns - * @start: starting user address - * @nr_frames: number of pages / pfns from start to map - * @write: whether pages will be written to by the caller - * @force: whether to force write access even if user mapping is - * readonly. See description of the same argument of - get_user_pages(). - * @vec: structure which receives pages / pfns of the addresses mapped. - * It should have space for at least nr_frames entries. - * - * This function maps virtual addresses from @start and fills @vec structure - * with page frame numbers or page pointers to corresponding pages (choice - * depends on the type of the vma underlying the virtual address). If @start - * belongs to a normal vma, the function grabs reference to each of the pages - * to pin them in memory. If @start belongs to VM_IO | VM_PFNMAP vma, we don't - * touch page structures and the caller must make sure pfns aren't reused for - * anything else while he is using them. - * - * The function returns number of pages mapped which may be less than - * @nr_frames. In particular we stop mapping if there are more vmas of - * different type underlying the specified range of virtual addresses. - * When the function isn't able to map a single page, it returns error. - * - * This function takes care of grabbing mmap_sem as necessary. - */ -int get_vaddr_frames(unsigned long start, unsigned int nr_frames, - bool write, bool force, struct frame_vector *vec) -{ - struct mm_struct *mm = current->mm; - struct vm_area_struct *vma; - int ret = 0; - int err; - int locked; - - if (nr_frames == 0) - return 0; - - if (WARN_ON_ONCE(nr_frames > vec->nr_allocated)) - nr_frames = vec->nr_allocated; - - down_read(&mm->mmap_sem); - locked = 1; - vma = find_vma_intersection(mm, start, start + 1); - if (!vma) { - ret = -EFAULT; - goto out; - } - if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) { - vec->got_ref = true; - vec->is_pfns = false; - ret = get_user_pages_locked(current, mm, start, nr_frames, - write, force, (struct page **)(vec->ptrs), &locked); - goto out; - } - - vec->got_ref = false; - vec->is_pfns = true; - do { - unsigned long *nums = frame_vector_pfns(vec); - - while (ret < nr_frames && start + PAGE_SIZE <= vma->vm_end) { - err = follow_pfn(vma, start, &nums[ret]); - if (err) { - if (ret == 0) - ret = err; - goto out; - } - start += PAGE_SIZE; - ret++; - } - /* - * We stop if we have enough pages or if VMA doesn't completely - * cover the tail page. - */ - if (ret >= nr_frames || start < vma->vm_end) - break; - vma = find_vma_intersection(mm, start, start + 1); - } while (vma && vma->vm_flags & (VM_IO | VM_PFNMAP)); -out: - if (locked) - up_read(&mm->mmap_sem); - if (!ret) - ret = -EFAULT; - if (ret > 0) - vec->nr_frames = ret; - return ret; -} -EXPORT_SYMBOL(get_vaddr_frames); - -/** - * put_vaddr_frames() - drop references to pages if get_vaddr_frames() acquired - * them - * @vec: frame vector to put - * - * Drop references to pages if get_vaddr_frames() acquired them. We also - * invalidate the frame vector so that it is prepared for the next call into - * get_vaddr_frames(). - */ -void put_vaddr_frames(struct frame_vector *vec) -{ - int i; - struct page **pages; - - if (!vec->got_ref) - goto out; - pages = frame_vector_pages(vec); - /* - * frame_vector_pages() might needed to do a conversion when - * get_vaddr_frames() got pages but vec was later converted to pfns. - * But it shouldn't really fail to convert pfns back... - */ - if (WARN_ON(IS_ERR(pages))) - goto out; - for (i = 0; i < vec->nr_frames; i++) - put_page(pages[i]); - vec->got_ref = false; -out: - vec->nr_frames = 0; -} -EXPORT_SYMBOL(put_vaddr_frames); - -/** - * frame_vector_to_pages - convert frame vector to contain page pointers - * @vec: frame vector to convert - * - * Convert @vec to contain array of page pointers. If the conversion is - * successful, return 0. Otherwise return an error. Note that we do not grab - * page references for the page structures. - */ -int frame_vector_to_pages(struct frame_vector *vec) -{ - int i; - unsigned long *nums; - struct page **pages; - - if (!vec->is_pfns) - return 0; - nums = frame_vector_pfns(vec); - for (i = 0; i < vec->nr_frames; i++) - if (!pfn_valid(nums[i])) - return -EINVAL; - pages = (struct page **)nums; - for (i = 0; i < vec->nr_frames; i++) - pages[i] = pfn_to_page(nums[i]); - vec->is_pfns = false; - return 0; -} -EXPORT_SYMBOL(frame_vector_to_pages); - -/** - * frame_vector_to_pfns - convert frame vector to contain pfns - * @vec: frame vector to convert - * - * Convert @vec to contain array of pfns. - */ -void frame_vector_to_pfns(struct frame_vector *vec) -{ - int i; - unsigned long *nums; - struct page **pages; - - if (vec->is_pfns) - return; - pages = (struct page **)(vec->ptrs); - nums = (unsigned long *)pages; - for (i = 0; i < vec->nr_frames; i++) - nums[i] = page_to_pfn(pages[i]); - vec->is_pfns = true; -} -EXPORT_SYMBOL(frame_vector_to_pfns); - -/** - * frame_vector_create() - allocate & initialize structure for pinned pfns - * @nr_frames: number of pfns slots we should reserve - * - * Allocate and initialize struct pinned_pfns to be able to hold @nr_pfns - * pfns. - */ -struct frame_vector *frame_vector_create(unsigned int nr_frames) -{ - struct frame_vector *vec; - int size = sizeof(struct frame_vector) + sizeof(void *) * nr_frames; - - if (WARN_ON_ONCE(nr_frames == 0)) - return NULL; - /* - * This is absurdly high. It's here just to avoid strange effects when - * arithmetics overflows. - */ - if (WARN_ON_ONCE(nr_frames > INT_MAX / sizeof(void *) / 2)) - return NULL; - /* - * Avoid higher order allocations, use vmalloc instead. It should - * be rare anyway. - */ - if (size <= PAGE_SIZE) - vec = kmalloc(size, GFP_KERNEL); - else - vec = vmalloc(size); - if (!vec) - return NULL; - vec->nr_allocated = nr_frames; - vec->nr_frames = 0; - return vec; -} -EXPORT_SYMBOL(frame_vector_create); - -/** - * frame_vector_destroy() - free memory allocated to carry frame vector - * @vec: Frame vector to free - * - * Free structure allocated by frame_vector_create() to carry frames. - */ -void frame_vector_destroy(struct frame_vector *vec) -{ - /* Make sure put_vaddr_frames() got called properly... */ - VM_BUG_ON(vec->nr_frames > 0); - if (!is_vmalloc_addr(vec)) - kfree(vec); - else - vfree(vec); -} -EXPORT_SYMBOL(frame_vector_destroy); - /** * get_dump_page() - pin user page in memory while writing it to core dump * @addr: user address