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
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
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?
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?
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 ofget_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 ofget_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
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 ofget_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 ofget_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
dri-devel@lists.freedesktop.org
-
Jan Kara -
Josh Triplett -
Mauro Carvalho Chehab