Merge tag 'media/v4.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab...
authorLinus Torvalds <torvalds@linux-foundation.org>
Fri, 11 Sep 2015 23:42:39 +0000 (16:42 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 11 Sep 2015 23:42:39 +0000 (16:42 -0700)
Pull media updates from Mauro Carvalho Chehab:
 "A series of patches that move part of the code used to allocate memory
  from the media subsystem to the mm subsystem"

[ The mm parts have been acked by VM people, and the series was
  apparently in -mm for a while   - Linus ]

* tag 'media/v4.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  [media] drm/exynos: Convert g2d_userptr_get_dma_addr() to use get_vaddr_frames()
  [media] media: vb2: Remove unused functions
  [media] media: vb2: Convert vb2_dc_get_userptr() to use frame vector
  [media] media: vb2: Convert vb2_vmalloc_get_userptr() to use frame vector
  [media] media: vb2: Convert vb2_dma_sg_get_userptr() to use frame vector
  [media] vb2: Provide helpers for mapping virtual addresses
  [media] media: omap_vout: Convert omap_vout_uservirt_to_phys() to use get_vaddr_pfns()
  [media] mm: Provide new get_vaddr_frames() helper
  [media] vb2: Push mmap_sem down to memops

16 files changed:
drivers/gpu/drm/exynos/Kconfig
drivers/gpu/drm/exynos/exynos_drm_g2d.c
drivers/gpu/drm/exynos/exynos_drm_gem.c
drivers/media/platform/omap/Kconfig
drivers/media/platform/omap/omap_vout.c
drivers/media/v4l2-core/Kconfig
drivers/media/v4l2-core/videobuf2-core.c
drivers/media/v4l2-core/videobuf2-dma-contig.c
drivers/media/v4l2-core/videobuf2-dma-sg.c
drivers/media/v4l2-core/videobuf2-memops.c
drivers/media/v4l2-core/videobuf2-vmalloc.c
include/linux/mm.h
include/media/videobuf2-memops.h
mm/Kconfig
mm/Makefile
mm/frame_vector.c [new file with mode: 0644]

index df0b61a60501c46ac6a58da5ae0ec993cbb7f9f4..bd1a4156f647b3b8cf3d26b97ee657c2b4b2bab6 100644 (file)
@@ -77,6 +77,7 @@ 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.
 
index 535b4ad6c4b14783a6ce099f81f4775759bd5ee6..3734c34aed16a22938509454cf794e5b4069ac35 100644 (file)
@@ -194,10 +194,8 @@ struct g2d_cmdlist_userptr {
        dma_addr_t              dma_addr;
        unsigned long           userptr;
        unsigned long           size;
-       struct page             **pages;
-       unsigned int            npages;
+       struct frame_vector     *vec;
        struct sg_table         *sgt;
-       struct vm_area_struct   *vma;
        atomic_t                refcount;
        bool                    in_pool;
        bool                    out_of_list;
@@ -367,6 +365,7 @@ static void g2d_userptr_put_dma_addr(struct drm_device *drm_dev,
 {
        struct g2d_cmdlist_userptr *g2d_userptr =
                                        (struct g2d_cmdlist_userptr *)obj;
+       struct page **pages;
 
        if (!obj)
                return;
@@ -386,19 +385,21 @@ out:
        exynos_gem_unmap_sgt_from_dma(drm_dev, g2d_userptr->sgt,
                                        DMA_BIDIRECTIONAL);
 
-       exynos_gem_put_pages_to_userptr(g2d_userptr->pages,
-                                       g2d_userptr->npages,
-                                       g2d_userptr->vma);
+       pages = frame_vector_pages(g2d_userptr->vec);
+       if (!IS_ERR(pages)) {
+               int i;
 
-       exynos_gem_put_vma(g2d_userptr->vma);
+               for (i = 0; i < frame_vector_count(g2d_userptr->vec); i++)
+                       set_page_dirty_lock(pages[i]);
+       }
+       put_vaddr_frames(g2d_userptr->vec);
+       frame_vector_destroy(g2d_userptr->vec);
 
        if (!g2d_userptr->out_of_list)
                list_del_init(&g2d_userptr->list);
 
        sg_free_table(g2d_userptr->sgt);
        kfree(g2d_userptr->sgt);
-
-       drm_free_large(g2d_userptr->pages);
        kfree(g2d_userptr);
 }
 
@@ -412,9 +413,7 @@ static dma_addr_t *g2d_userptr_get_dma_addr(struct drm_device *drm_dev,
        struct exynos_drm_g2d_private *g2d_priv = file_priv->g2d_priv;
        struct g2d_cmdlist_userptr *g2d_userptr;
        struct g2d_data *g2d;
-       struct page **pages;
        struct sg_table *sgt;
-       struct vm_area_struct *vma;
        unsigned long start, end;
        unsigned int npages, offset;
        int ret;
@@ -460,65 +459,40 @@ static dma_addr_t *g2d_userptr_get_dma_addr(struct drm_device *drm_dev,
                return ERR_PTR(-ENOMEM);
 
        atomic_set(&g2d_userptr->refcount, 1);
+       g2d_userptr->size = size;
 
        start = userptr & PAGE_MASK;
        offset = userptr & ~PAGE_MASK;
        end = PAGE_ALIGN(userptr + size);
        npages = (end - start) >> PAGE_SHIFT;
-       g2d_userptr->npages = npages;
-
-       pages = drm_calloc_large(npages, sizeof(struct page *));
-       if (!pages) {
-               DRM_ERROR("failed to allocate pages.\n");
+       g2d_userptr->vec = frame_vector_create(npages);
+       if (!g2d_userptr->vec) {
                ret = -ENOMEM;
                goto err_free;
        }
 
-       down_read(&current->mm->mmap_sem);
-       vma = find_vma(current->mm, userptr);
-       if (!vma) {
-               up_read(&current->mm->mmap_sem);
-               DRM_ERROR("failed to get vm region.\n");
+       ret = get_vaddr_frames(start, npages, true, true, g2d_userptr->vec);
+       if (ret != npages) {
+               DRM_ERROR("failed to get user pages from userptr.\n");
+               if (ret < 0)
+                       goto err_destroy_framevec;
                ret = -EFAULT;
-               goto err_free_pages;
+               goto err_put_framevec;
        }
-
-       if (vma->vm_end < userptr + size) {
-               up_read(&current->mm->mmap_sem);
-               DRM_ERROR("vma is too small.\n");
+       if (frame_vector_to_pages(g2d_userptr->vec) < 0) {
                ret = -EFAULT;
-               goto err_free_pages;
-       }
-
-       g2d_userptr->vma = exynos_gem_get_vma(vma);
-       if (!g2d_userptr->vma) {
-               up_read(&current->mm->mmap_sem);
-               DRM_ERROR("failed to copy vma.\n");
-               ret = -ENOMEM;
-               goto err_free_pages;
-       }
-
-       g2d_userptr->size = size;
-
-       ret = exynos_gem_get_pages_from_userptr(start & PAGE_MASK,
-                                               npages, pages, vma);
-       if (ret < 0) {
-               up_read(&current->mm->mmap_sem);
-               DRM_ERROR("failed to get user pages from userptr.\n");
-               goto err_put_vma;
+               goto err_put_framevec;
        }
 
-       up_read(&current->mm->mmap_sem);
-       g2d_userptr->pages = pages;
-
        sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
        if (!sgt) {
                ret = -ENOMEM;
-               goto err_free_userptr;
+               goto err_put_framevec;
        }
 
-       ret = sg_alloc_table_from_pages(sgt, pages, npages, offset,
-                                       size, GFP_KERNEL);
+       ret = sg_alloc_table_from_pages(sgt,
+                                       frame_vector_pages(g2d_userptr->vec),
+                                       npages, offset, size, GFP_KERNEL);
        if (ret < 0) {
                DRM_ERROR("failed to get sgt from pages.\n");
                goto err_free_sgt;
@@ -553,16 +527,11 @@ err_sg_free_table:
 err_free_sgt:
        kfree(sgt);
 
-err_free_userptr:
-       exynos_gem_put_pages_to_userptr(g2d_userptr->pages,
-                                       g2d_userptr->npages,
-                                       g2d_userptr->vma);
-
-err_put_vma:
-       exynos_gem_put_vma(g2d_userptr->vma);
+err_put_framevec:
+       put_vaddr_frames(g2d_userptr->vec);
 
-err_free_pages:
-       drm_free_large(pages);
+err_destroy_framevec:
+       frame_vector_destroy(g2d_userptr->vec);
 
 err_free:
        kfree(g2d_userptr);
index 62b9ea1b07fb005c04da732490c06e91a2996e21..f12fbc36b120065902c50253a4e91e9cc8952df5 100644 (file)
@@ -366,103 +366,6 @@ int exynos_drm_gem_get_ioctl(struct drm_device *dev, void *data,
        return 0;
 }
 
-struct vm_area_struct *exynos_gem_get_vma(struct vm_area_struct *vma)
-{
-       struct vm_area_struct *vma_copy;
-
-       vma_copy = kmalloc(sizeof(*vma_copy), GFP_KERNEL);
-       if (!vma_copy)
-               return NULL;
-
-       if (vma->vm_ops && vma->vm_ops->open)
-               vma->vm_ops->open(vma);
-
-       if (vma->vm_file)
-               get_file(vma->vm_file);
-
-       memcpy(vma_copy, vma, sizeof(*vma));
-
-       vma_copy->vm_mm = NULL;
-       vma_copy->vm_next = NULL;
-       vma_copy->vm_prev = NULL;
-
-       return vma_copy;
-}
-
-void exynos_gem_put_vma(struct vm_area_struct *vma)
-{
-       if (!vma)
-               return;
-
-       if (vma->vm_ops && vma->vm_ops->close)
-               vma->vm_ops->close(vma);
-
-       if (vma->vm_file)
-               fput(vma->vm_file);
-
-       kfree(vma);
-}
-
-int exynos_gem_get_pages_from_userptr(unsigned long start,
-                                               unsigned int npages,
-                                               struct page **pages,
-                                               struct vm_area_struct *vma)
-{
-       int get_npages;
-
-       /* the memory region mmaped with VM_PFNMAP. */
-       if (vma_is_io(vma)) {
-               unsigned int i;
-
-               for (i = 0; i < npages; ++i, start += PAGE_SIZE) {
-                       unsigned long pfn;
-                       int ret = follow_pfn(vma, start, &pfn);
-                       if (ret)
-                               return ret;
-
-                       pages[i] = pfn_to_page(pfn);
-               }
-
-               if (i != npages) {
-                       DRM_ERROR("failed to get user_pages.\n");
-                       return -EINVAL;
-               }
-
-               return 0;
-       }
-
-       get_npages = get_user_pages(current, current->mm, start,
-                                       npages, 1, 1, pages, NULL);
-       get_npages = max(get_npages, 0);
-       if (get_npages != npages) {
-               DRM_ERROR("failed to get user_pages.\n");
-               while (get_npages)
-                       put_page(pages[--get_npages]);
-               return -EFAULT;
-       }
-
-       return 0;
-}
-
-void exynos_gem_put_pages_to_userptr(struct page **pages,
-                                       unsigned int npages,
-                                       struct vm_area_struct *vma)
-{
-       if (!vma_is_io(vma)) {
-               unsigned int i;
-
-               for (i = 0; i < npages; i++) {
-                       set_page_dirty_lock(pages[i]);
-
-                       /*
-                        * undo the reference we took when populating
-                        * the table.
-                        */
-                       put_page(pages[i]);
-               }
-       }
-}
-
 int exynos_gem_map_sgt_with_dma(struct drm_device *drm_dev,
                                struct sg_table *sgt,
                                enum dma_data_direction dir)
index dc2aaab54aef7bf050b24f5921194b5598c7690c..217d613b0fe7a66c53b0085696d43345728df761 100644 (file)
@@ -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.
index de2474e1132de486ae73f5581555f814a299b390..70c28d19ea04c8a7cfa452a6c68d0452094d6fcb 100644 (file)
@@ -195,46 +195,34 @@ static int omap_vout_try_format(struct v4l2_pix_format *pix)
 }
 
 /*
- * omap_vout_uservirt_to_phys: This inline function is used to convert user
- * space virtual address to physical address.
+ * omap_vout_get_userptr: Convert user space virtual address to physical
+ * address.
  */
-static unsigned long omap_vout_uservirt_to_phys(unsigned long virtp)
+static int omap_vout_get_userptr(struct videobuf_buffer *vb, u32 virtp,
+                                u32 *physp)
 {
-       unsigned long physp = 0;
-       struct vm_area_struct *vma;
-       struct mm_struct *mm = current->mm;
+       struct frame_vector *vec;
+       int ret;
 
        /* For kernel direct-mapped memory, take the easy way */
-       if (virtp >= PAGE_OFFSET)
-               return virt_to_phys((void *) virtp);
-
-       down_read(&current->mm->mmap_sem);
-       vma = find_vma(mm, virtp);
-       if (vma && (vma->vm_flags & VM_IO) && vma->vm_pgoff) {
-               /* this will catch, kernel-allocated, mmaped-to-usermode
-                  addresses */
-               physp = (vma->vm_pgoff << PAGE_SHIFT) + (virtp - vma->vm_start);
-               up_read(&current->mm->mmap_sem);
-       } else {
-               /* otherwise, use get_user_pages() for general userland pages */
-               int res, nr_pages = 1;
-               struct page *pages;
+       if (virtp >= PAGE_OFFSET) {
+               *physp = virt_to_phys((void *)virtp);
+               return 0;
+       }
 
-               res = get_user_pages(current, current->mm, virtp, nr_pages, 1,
-                               0, &pages, NULL);
-               up_read(&current->mm->mmap_sem);
+       vec = frame_vector_create(1);
+       if (!vec)
+               return -ENOMEM;
 
-               if (res == nr_pages) {
-                       physp =  __pa(page_address(&pages[0]) +
-                                       (virtp & ~PAGE_MASK));
-               } else {
-                       printk(KERN_WARNING VOUT_NAME
-                                       "get_user_pages failed\n");
-                       return 0;
-               }
+       ret = get_vaddr_frames(virtp, 1, true, false, vec);
+       if (ret != 1) {
+               frame_vector_destroy(vec);
+               return -EINVAL;
        }
+       *physp = __pfn_to_phys(frame_vector_pfns(vec)[0]);
+       vb->priv = vec;
 
-       return physp;
+       return 0;
 }
 
 /*
@@ -784,11 +772,15 @@ static int omap_vout_buffer_prepare(struct videobuf_queue *q,
         * address of the buffer
         */
        if (V4L2_MEMORY_USERPTR == vb->memory) {
+               int ret;
+
                if (0 == vb->baddr)
                        return -EINVAL;
                /* Physical address */
-               vout->queued_buf_addr[vb->i] = (u8 *)
-                       omap_vout_uservirt_to_phys(vb->baddr);
+               ret = omap_vout_get_userptr(vb, vb->baddr,
+                               (u32 *)&vout->queued_buf_addr[vb->i]);
+               if (ret < 0)
+                       return ret;
        } else {
                unsigned long addr, dma_addr;
                unsigned long size;
@@ -834,12 +826,13 @@ static void omap_vout_buffer_queue(struct videobuf_queue *q,
 static void omap_vout_buffer_release(struct videobuf_queue *q,
                            struct videobuf_buffer *vb)
 {
-       struct omap_vout_device *vout = q->priv_data;
-
        vb->state = VIDEOBUF_NEEDS_INIT;
+       if (vb->memory == V4L2_MEMORY_USERPTR && vb->priv) {
+               struct frame_vector *vec = vb->priv;
 
-       if (V4L2_MEMORY_MMAP != vout->memory)
-               return;
+               put_vaddr_frames(vec);
+               frame_vector_destroy(vec);
+       }
 }
 
 /*
index b4b022933e29e463c8075b53a2ec8b0a0d7271b5..82876a67f1449b62f02142f4a677aee8880c295a 100644 (file)
@@ -84,6 +84,7 @@ config VIDEOBUF2_CORE
 
 config VIDEOBUF2_MEMOPS
        tristate
+       select FRAME_VECTOR
 
 config VIDEOBUF2_DMA_CONTIG
        tristate
index f1022d810d2208f92057b3cf25eddabd5973aa90..4f59b7ec05d0fe7261312082d7ee2c2e17453b53 100644 (file)
@@ -1691,9 +1691,7 @@ static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b)
                ret = __qbuf_mmap(vb, b);
                break;
        case V4L2_MEMORY_USERPTR:
-               down_read(&current->mm->mmap_sem);
                ret = __qbuf_userptr(vb, b);
-               up_read(&current->mm->mmap_sem);
                break;
        case V4L2_MEMORY_DMABUF:
                ret = __qbuf_dmabuf(vb, b);
index 94c1e6455d365de7faa1b4b0df14ce279820d5f2..2397ceb1dc6b3743f18fefe4ddc958ecb5c6589c 100644 (file)
@@ -32,15 +32,13 @@ struct vb2_dc_buf {
        dma_addr_t                      dma_addr;
        enum dma_data_direction         dma_dir;
        struct sg_table                 *dma_sgt;
+       struct frame_vector             *vec;
 
        /* MMAP related */
        struct vb2_vmarea_handler       handler;
        atomic_t                        refcount;
        struct sg_table                 *sgt_base;
 
-       /* USERPTR related */
-       struct vm_area_struct           *vma;
-
        /* DMABUF related */
        struct dma_buf_attachment       *db_attach;
 };
@@ -49,24 +47,6 @@ struct vb2_dc_buf {
 /*        scatterlist table functions        */
 /*********************************************/
 
-
-static void vb2_dc_sgt_foreach_page(struct sg_table *sgt,
-       void (*cb)(struct page *pg))
-{
-       struct scatterlist *s;
-       unsigned int i;
-
-       for_each_sg(sgt->sgl, s, sgt->orig_nents, i) {
-               struct page *page = sg_page(s);
-               unsigned int n_pages = PAGE_ALIGN(s->offset + s->length)
-                       >> PAGE_SHIFT;
-               unsigned int j;
-
-               for (j = 0; j < n_pages; ++j, ++page)
-                       cb(page);
-       }
-}
-
 static unsigned long vb2_dc_get_contiguous_size(struct sg_table *sgt)
 {
        struct scatterlist *s;
@@ -429,92 +409,12 @@ static struct dma_buf *vb2_dc_get_dmabuf(void *buf_priv, unsigned long flags)
 /*       callbacks for USERPTR buffers       */
 /*********************************************/
 
-static inline int vma_is_io(struct vm_area_struct *vma)
-{
-       return !!(vma->vm_flags & (VM_IO | VM_PFNMAP));
-}
-
-static int vb2_dc_get_user_pfn(unsigned long start, int n_pages,
-       struct vm_area_struct *vma, unsigned long *res)
-{
-       unsigned long pfn, start_pfn, prev_pfn;
-       unsigned int i;
-       int ret;
-
-       if (!vma_is_io(vma))
-               return -EFAULT;
-
-       ret = follow_pfn(vma, start, &pfn);
-       if (ret)
-               return ret;
-
-       start_pfn = pfn;
-       start += PAGE_SIZE;
-
-       for (i = 1; i < n_pages; ++i, start += PAGE_SIZE) {
-               prev_pfn = pfn;
-               ret = follow_pfn(vma, start, &pfn);
-
-               if (ret) {
-                       pr_err("no page for address %lu\n", start);
-                       return ret;
-               }
-               if (pfn != prev_pfn + 1)
-                       return -EINVAL;
-       }
-
-       *res = start_pfn;
-       return 0;
-}
-
-static int vb2_dc_get_user_pages(unsigned long start, struct page **pages,
-       int n_pages, struct vm_area_struct *vma,
-       enum dma_data_direction dma_dir)
-{
-       if (vma_is_io(vma)) {
-               unsigned int i;
-
-               for (i = 0; i < n_pages; ++i, start += PAGE_SIZE) {
-                       unsigned long pfn;
-                       int ret = follow_pfn(vma, start, &pfn);
-
-                       if (!pfn_valid(pfn))
-                               return -EINVAL;
-
-                       if (ret) {
-                               pr_err("no page for address %lu\n", start);
-                               return ret;
-                       }
-                       pages[i] = pfn_to_page(pfn);
-               }
-       } else {
-               int n;
-
-               n = get_user_pages(current, current->mm, start & PAGE_MASK,
-                       n_pages, dma_dir == DMA_FROM_DEVICE, 1, pages, NULL);
-               /* negative error means that no page was pinned */
-               n = max(n, 0);
-               if (n != n_pages) {
-                       pr_err("got only %d of %d user pages\n", n, n_pages);
-                       while (n)
-                               put_page(pages[--n]);
-                       return -EFAULT;
-               }
-       }
-
-       return 0;
-}
-
-static void vb2_dc_put_dirty_page(struct page *page)
-{
-       set_page_dirty_lock(page);
-       put_page(page);
-}
-
 static void vb2_dc_put_userptr(void *buf_priv)
 {
        struct vb2_dc_buf *buf = buf_priv;
        struct sg_table *sgt = buf->dma_sgt;
+       int i;
+       struct page **pages;
 
        if (sgt) {
                DEFINE_DMA_ATTRS(attrs);
@@ -526,13 +426,15 @@ static void vb2_dc_put_userptr(void *buf_priv)
                 */
                dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
                                   buf->dma_dir, &attrs);
-               if (!vma_is_io(buf->vma))
-                       vb2_dc_sgt_foreach_page(sgt, vb2_dc_put_dirty_page);
-
+               pages = frame_vector_pages(buf->vec);
+               /* sgt should exist only if vector contains pages... */
+               BUG_ON(IS_ERR(pages));
+               for (i = 0; i < frame_vector_count(buf->vec); i++)
+                       set_page_dirty_lock(pages[i]);
                sg_free_table(sgt);
                kfree(sgt);
        }
-       vb2_put_vma(buf->vma);
+       vb2_destroy_framevec(buf->vec);
        kfree(buf);
 }
 
@@ -572,13 +474,10 @@ static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr,
 {
        struct vb2_dc_conf *conf = alloc_ctx;
        struct vb2_dc_buf *buf;
-       unsigned long start;
-       unsigned long end;
+       struct frame_vector *vec;
        unsigned long offset;
-       struct page **pages;
-       int n_pages;
+       int n_pages, i;
        int ret = 0;
-       struct vm_area_struct *vma;
        struct sg_table *sgt;
        unsigned long contig_size;
        unsigned long dma_align = dma_get_cache_alignment();
@@ -604,72 +503,43 @@ static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr,
        buf->dev = conf->dev;
        buf->dma_dir = dma_dir;
 
-       start = vaddr & PAGE_MASK;
        offset = vaddr & ~PAGE_MASK;
-       end = PAGE_ALIGN(vaddr + size);
-       n_pages = (end - start) >> PAGE_SHIFT;
-
-       pages = kmalloc(n_pages * sizeof(pages[0]), GFP_KERNEL);
-       if (!pages) {
-               ret = -ENOMEM;
-               pr_err("failed to allocate pages table\n");
+       vec = vb2_create_framevec(vaddr, size, dma_dir == DMA_FROM_DEVICE);
+       if (IS_ERR(vec)) {
+               ret = PTR_ERR(vec);
                goto fail_buf;
        }
+       buf->vec = vec;
+       n_pages = frame_vector_count(vec);
+       ret = frame_vector_to_pages(vec);
+       if (ret < 0) {
+               unsigned long *nums = frame_vector_pfns(vec);
 
-       /* current->mm->mmap_sem is taken by videobuf2 core */
-       vma = find_vma(current->mm, vaddr);
-       if (!vma) {
-               pr_err("no vma for address %lu\n", vaddr);
-               ret = -EFAULT;
-               goto fail_pages;
-       }
-
-       if (vma->vm_end < vaddr + size) {
-               pr_err("vma at %lu is too small for %lu bytes\n", vaddr, size);
-               ret = -EFAULT;
-               goto fail_pages;
-       }
-
-       buf->vma = vb2_get_vma(vma);
-       if (!buf->vma) {
-               pr_err("failed to copy vma\n");
-               ret = -ENOMEM;
-               goto fail_pages;
-       }
-
-       /* extract page list from userspace mapping */
-       ret = vb2_dc_get_user_pages(start, pages, n_pages, vma, dma_dir);
-       if (ret) {
-               unsigned long pfn;
-               if (vb2_dc_get_user_pfn(start, n_pages, vma, &pfn) == 0) {
-                       buf->dma_addr = vb2_dc_pfn_to_dma(buf->dev, pfn);
-                       buf->size = size;
-                       kfree(pages);
-                       return buf;
-               }
-
-               pr_err("failed to get user pages\n");
-               goto fail_vma;
+               /*
+                * Failed to convert to pages... Check the memory is physically
+                * contiguous and use direct mapping
+                */
+               for (i = 1; i < n_pages; i++)
+                       if (nums[i-1] + 1 != nums[i])
+                               goto fail_pfnvec;
+               buf->dma_addr = vb2_dc_pfn_to_dma(buf->dev, nums[0]);
+               goto out;
        }
 
        sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
        if (!sgt) {
                pr_err("failed to allocate sg table\n");
                ret = -ENOMEM;
-               goto fail_get_user_pages;
+               goto fail_pfnvec;
        }
 
-       ret = sg_alloc_table_from_pages(sgt, pages, n_pages,
+       ret = sg_alloc_table_from_pages(sgt, frame_vector_pages(vec), n_pages,
                offset, size, GFP_KERNEL);
        if (ret) {
                pr_err("failed to initialize sg table\n");
                goto fail_sgt;
        }
 
-       /* pages are no longer needed */
-       kfree(pages);
-       pages = NULL;
-
        /*
         * No need to sync to the device, this will happen later when the
         * prepare() memop is called.
@@ -691,8 +561,9 @@ static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr,
        }
 
        buf->dma_addr = sg_dma_address(sgt->sgl);
-       buf->size = size;
        buf->dma_sgt = sgt;
+out:
+       buf->size = size;
 
        return buf;
 
@@ -701,23 +572,13 @@ fail_map_sg:
                           buf->dma_dir, &attrs);
 
 fail_sgt_init:
-       if (!vma_is_io(buf->vma))
-               vb2_dc_sgt_foreach_page(sgt, put_page);
        sg_free_table(sgt);
 
 fail_sgt:
        kfree(sgt);
 
-fail_get_user_pages:
-       if (pages && !vma_is_io(buf->vma))
-               while (n_pages)
-                       put_page(pages[--n_pages]);
-
-fail_vma:
-       vb2_put_vma(buf->vma);
-
-fail_pages:
-       kfree(pages); /* kfree is NULL-proof */
+fail_pfnvec:
+       vb2_destroy_framevec(vec);
 
 fail_buf:
        kfree(buf);
index 7289b81bd7b72e46acf5f522a2341a31088020e4..be7bd6535c9d87d6bc3839e4bccae160f2251047 100644 (file)
@@ -38,6 +38,7 @@ struct vb2_dma_sg_buf {
        struct device                   *dev;
        void                            *vaddr;
        struct page                     **pages;
+       struct frame_vector             *vec;
        int                             offset;
        enum dma_data_direction         dma_dir;
        struct sg_table                 sg_table;
@@ -51,7 +52,6 @@ struct vb2_dma_sg_buf {
        unsigned int                    num_pages;
        atomic_t                        refcount;
        struct vb2_vmarea_handler       handler;
-       struct vm_area_struct           *vma;
 
        struct dma_buf_attachment       *db_attach;
 };
@@ -225,25 +225,17 @@ static void vb2_dma_sg_finish(void *buf_priv)
        dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
 }
 
-static inline int vma_is_io(struct vm_area_struct *vma)
-{
-       return !!(vma->vm_flags & (VM_IO | VM_PFNMAP));
-}
-
 static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
                                    unsigned long size,
                                    enum dma_data_direction dma_dir)
 {
        struct vb2_dma_sg_conf *conf = alloc_ctx;
        struct vb2_dma_sg_buf *buf;
-       unsigned long first, last;
-       int num_pages_from_user;
-       struct vm_area_struct *vma;
        struct sg_table *sgt;
        DEFINE_DMA_ATTRS(attrs);
+       struct frame_vector *vec;
 
        dma_set_attr(DMA_ATTR_SKIP_CPU_SYNC, &attrs);
-
        buf = kzalloc(sizeof *buf, GFP_KERNEL);
        if (!buf)
                return NULL;
@@ -254,61 +246,19 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
        buf->offset = vaddr & ~PAGE_MASK;
        buf->size = size;
        buf->dma_sgt = &buf->sg_table;
+       vec = vb2_create_framevec(vaddr, size, buf->dma_dir == DMA_FROM_DEVICE);
+       if (IS_ERR(vec))
+               goto userptr_fail_pfnvec;
+       buf->vec = vec;
 
-       first = (vaddr           & PAGE_MASK) >> PAGE_SHIFT;
-       last  = ((vaddr + size - 1) & PAGE_MASK) >> PAGE_SHIFT;
-       buf->num_pages = last - first + 1;
-
-       buf->pages = kzalloc(buf->num_pages * sizeof(struct page *),
-                            GFP_KERNEL);
-       if (!buf->pages)
-               goto userptr_fail_alloc_pages;
-
-       vma = find_vma(current->mm, vaddr);
-       if (!vma) {
-               dprintk(1, "no vma for address %lu\n", vaddr);
-               goto userptr_fail_find_vma;
-       }
-
-       if (vma->vm_end < vaddr + size) {
-               dprintk(1, "vma at %lu is too small for %lu bytes\n",
-                       vaddr, size);
-               goto userptr_fail_find_vma;
-       }
-
-       buf->vma = vb2_get_vma(vma);
-       if (!buf->vma) {
-               dprintk(1, "failed to copy vma\n");
-               goto userptr_fail_find_vma;
-       }
-
-       if (vma_is_io(buf->vma)) {
-               for (num_pages_from_user = 0;
-                    num_pages_from_user < buf->num_pages;
-                    ++num_pages_from_user, vaddr += PAGE_SIZE) {
-                       unsigned long pfn;
-
-                       if (follow_pfn(vma, vaddr, &pfn)) {
-                               dprintk(1, "no page for address %lu\n", vaddr);
-                               break;
-                       }
-                       buf->pages[num_pages_from_user] = pfn_to_page(pfn);
-               }
-       } else
-               num_pages_from_user = get_user_pages(current, current->mm,
-                                            vaddr & PAGE_MASK,
-                                            buf->num_pages,
-                                            buf->dma_dir == DMA_FROM_DEVICE,
-                                            1, /* force */
-                                            buf->pages,
-                                            NULL);
-
-       if (num_pages_from_user != buf->num_pages)
-               goto userptr_fail_get_user_pages;
+       buf->pages = frame_vector_pages(vec);
+       if (IS_ERR(buf->pages))
+               goto userptr_fail_sgtable;
+       buf->num_pages = frame_vector_count(vec);
 
        if (sg_alloc_table_from_pages(buf->dma_sgt, buf->pages,
                        buf->num_pages, buf->offset, size, 0))
-               goto userptr_fail_alloc_table_from_pages;
+               goto userptr_fail_sgtable;
 
        sgt = &buf->sg_table;
        /*
@@ -324,17 +274,9 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
 
 userptr_fail_map:
        sg_free_table(&buf->sg_table);
-userptr_fail_alloc_table_from_pages:
-userptr_fail_get_user_pages:
-       dprintk(1, "get_user_pages requested/got: %d/%d]\n",
-               buf->num_pages, num_pages_from_user);
-       if (!vma_is_io(buf->vma))
-               while (--num_pages_from_user >= 0)
-                       put_page(buf->pages[num_pages_from_user]);
-       vb2_put_vma(buf->vma);
-userptr_fail_find_vma:
-       kfree(buf->pages);
-userptr_fail_alloc_pages:
+userptr_fail_sgtable:
+       vb2_destroy_framevec(vec);
+userptr_fail_pfnvec:
        kfree(buf);
        return NULL;
 }
@@ -362,11 +304,8 @@ static void vb2_dma_sg_put_userptr(void *buf_priv)
        while (--i >= 0) {
                if (buf->dma_dir == DMA_FROM_DEVICE)
                        set_page_dirty_lock(buf->pages[i]);
-               if (!vma_is_io(buf->vma))
-                       put_page(buf->pages[i]);
        }
-       kfree(buf->pages);
-       vb2_put_vma(buf->vma);
+       vb2_destroy_framevec(buf->vec);
        kfree(buf);
 }
 
index 0d49b7951f84a55a0d996ba90412b49ec249762c..48c6a49c4928f0446d53526c6cbda0b52ef3e08f 100644 (file)
 #include <media/videobuf2-memops.h>
 
 /**
- * vb2_get_vma() - acquire and lock the virtual memory area
- * @vma:       given virtual memory area
+ * vb2_create_framevec() - map virtual addresses to pfns
+ * @start:     Virtual user address where we start mapping
+ * @length:    Length of a range to map
+ * @write:     Should we map for writing into the area
  *
- * This function attempts to acquire an area mapped in the userspace for
- * the duration of a hardware operation. The area is "locked" by performing
- * the same set of operation that are done when process calls fork() and
- * memory areas are duplicated.
- *
- * Returns a copy of a virtual memory region on success or NULL.
- */
-struct vm_area_struct *vb2_get_vma(struct vm_area_struct *vma)
-{
-       struct vm_area_struct *vma_copy;
-
-       vma_copy = kmalloc(sizeof(*vma_copy), GFP_KERNEL);
-       if (vma_copy == NULL)
-               return NULL;
-
-       if (vma->vm_ops && vma->vm_ops->open)
-               vma->vm_ops->open(vma);
-
-       if (vma->vm_file)
-               get_file(vma->vm_file);
-
-       memcpy(vma_copy, vma, sizeof(*vma));
-
-       vma_copy->vm_mm = NULL;
-       vma_copy->vm_next = NULL;
-       vma_copy->vm_prev = NULL;
-
-       return vma_copy;
-}
-EXPORT_SYMBOL_GPL(vb2_get_vma);
-
-/**
- * vb2_put_userptr() - release a userspace virtual memory area
- * @vma:       virtual memory region associated with the area to be released
- *
- * This function releases the previously acquired memory area after a hardware
- * operation.
+ * This function allocates and fills in a vector with pfns corresponding to
+ * virtual address range passed in arguments. If pfns have corresponding pages,
+ * page references are also grabbed to pin pages in memory. The function
+ * returns pointer to the vector on success and error pointer in case of
+ * failure. Returned vector needs to be freed via vb2_destroy_pfnvec().
  */
-void vb2_put_vma(struct vm_area_struct *vma)
+struct frame_vector *vb2_create_framevec(unsigned long start,
+                                        unsigned long length,
+                                        bool write)
 {
-       if (!vma)
-               return;
-
-       if (vma->vm_ops && vma->vm_ops->close)
-               vma->vm_ops->close(vma);
-
-       if (vma->vm_file)
-               fput(vma->vm_file);
-
-       kfree(vma);
+       int ret;
+       unsigned long first, last;
+       unsigned long nr;
+       struct frame_vector *vec;
+
+       first = start >> PAGE_SHIFT;
+       last = (start + length - 1) >> PAGE_SHIFT;
+       nr = last - first + 1;
+       vec = frame_vector_create(nr);
+       if (!vec)
+               return ERR_PTR(-ENOMEM);
+       ret = get_vaddr_frames(start, nr, write, 1, vec);
+       if (ret < 0)
+               goto out_destroy;
+       /* We accept only complete set of PFNs */
+       if (ret != nr) {
+               ret = -EFAULT;
+               goto out_release;
+       }
+       return vec;
+out_release:
+       put_vaddr_frames(vec);
+out_destroy:
+       frame_vector_destroy(vec);
+       return ERR_PTR(ret);
 }
-EXPORT_SYMBOL_GPL(vb2_put_vma);
+EXPORT_SYMBOL(vb2_create_framevec);
 
 /**
- * vb2_get_contig_userptr() - lock physically contiguous userspace mapped memory
- * @vaddr:     starting virtual address of the area to be verified
- * @size:      size of the area
- * @res_paddr: will return physical address for the given vaddr
- * @res_vma:   will return locked copy of struct vm_area for the given area
- *
- * This function will go through memory area of size @size mapped at @vaddr and
- * verify that the underlying physical pages are contiguous. If they are
- * contiguous the virtual memory area is locked and a @res_vma is filled with
- * the copy and @res_pa set to the physical address of the buffer.
+ * vb2_destroy_framevec() - release vector of mapped pfns
+ * @vec:       vector of pfns / pages to release
  *
- * Returns 0 on success.
+ * This releases references to all pages in the vector @vec (if corresponding
+ * pfns are backed by pages) and frees the passed vector.
  */
-int vb2_get_contig_userptr(unsigned long vaddr, unsigned long size,
-                          struct vm_area_struct **res_vma, dma_addr_t *res_pa)
+void vb2_destroy_framevec(struct frame_vector *vec)
 {
-       struct mm_struct *mm = current->mm;
-       struct vm_area_struct *vma;
-       unsigned long offset, start, end;
-       unsigned long this_pfn, prev_pfn;
-       dma_addr_t pa = 0;
-
-       start = vaddr;
-       offset = start & ~PAGE_MASK;
-       end = start + size;
-
-       vma = find_vma(mm, start);
-
-       if (vma == NULL || vma->vm_end < end)
-               return -EFAULT;
-
-       for (prev_pfn = 0; start < end; start += PAGE_SIZE) {
-               int ret = follow_pfn(vma, start, &this_pfn);
-               if (ret)
-                       return ret;
-
-               if (prev_pfn == 0)
-                       pa = this_pfn << PAGE_SHIFT;
-               else if (this_pfn != prev_pfn + 1)
-                       return -EFAULT;
-
-               prev_pfn = this_pfn;
-       }
-
-       /*
-        * Memory is contiguous, lock vma and return to the caller
-        */
-       *res_vma = vb2_get_vma(vma);
-       if (*res_vma == NULL)
-               return -ENOMEM;
-
-       *res_pa = pa + offset;
-       return 0;
+       put_vaddr_frames(vec);
+       frame_vector_destroy(vec);
 }
-EXPORT_SYMBOL_GPL(vb2_get_contig_userptr);
+EXPORT_SYMBOL(vb2_destroy_framevec);
 
 /**
  * vb2_common_vm_open() - increase refcount of the vma
index 2fe4c27f524a85d9732ba4cbc72f5979f954466f..ecb8f0c7f0253b7eef10e97e3e88bd7e25c28296 100644 (file)
 
 struct vb2_vmalloc_buf {
        void                            *vaddr;
-       struct page                     **pages;
-       struct vm_area_struct           *vma;
+       struct frame_vector             *vec;
        enum dma_data_direction         dma_dir;
        unsigned long                   size;
-       unsigned int                    n_pages;
        atomic_t                        refcount;
        struct vb2_vmarea_handler       handler;
        struct dma_buf                  *dbuf;
@@ -76,10 +74,8 @@ static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr,
                                     enum dma_data_direction dma_dir)
 {
        struct vb2_vmalloc_buf *buf;
-       unsigned long first, last;
-       int n_pages, offset;
-       struct vm_area_struct *vma;
-       dma_addr_t physp;
+       struct frame_vector *vec;
+       int n_pages, offset, i;
 
        buf = kzalloc(sizeof(*buf), GFP_KERNEL);
        if (!buf)
@@ -88,51 +84,36 @@ static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr,
        buf->dma_dir = dma_dir;
        offset = vaddr & ~PAGE_MASK;
        buf->size = size;
-
-
-       vma = find_vma(current->mm, vaddr);
-       if (vma && (vma->vm_flags & VM_PFNMAP) && (vma->vm_pgoff)) {
-               if (vb2_get_contig_userptr(vaddr, size, &vma, &physp))
-                       goto fail_pages_array_alloc;
-               buf->vma = vma;
-               buf->vaddr = (__force void *)ioremap_nocache(physp, size);
-               if (!buf->vaddr)
-                       goto fail_pages_array_alloc;
+       vec = vb2_create_framevec(vaddr, size, dma_dir == DMA_FROM_DEVICE);
+       if (IS_ERR(vec))
+               goto fail_pfnvec_create;
+       buf->vec = vec;
+       n_pages = frame_vector_count(vec);
+       if (frame_vector_to_pages(vec) < 0) {
+               unsigned long *nums = frame_vector_pfns(vec);
+
+               /*
+                * We cannot get page pointers for these pfns. Check memory is
+                * physically contiguous and use direct mapping.
+                */
+               for (i = 1; i < n_pages; i++)
+                       if (nums[i-1] + 1 != nums[i])
+                               goto fail_map;
+               buf->vaddr = (__force void *)
+                               ioremap_nocache(nums[0] << PAGE_SHIFT, size);
        } else {
-               first = vaddr >> PAGE_SHIFT;
-               last  = (vaddr + size - 1) >> PAGE_SHIFT;
-               buf->n_pages = last - first + 1;
-               buf->pages = kzalloc(buf->n_pages * sizeof(struct page *),
-                                    GFP_KERNEL);
-               if (!buf->pages)
-                       goto fail_pages_array_alloc;
-
-               /* current->mm->mmap_sem is taken by videobuf2 core */
-               n_pages = get_user_pages(current, current->mm,
-                                        vaddr & PAGE_MASK, buf->n_pages,
-                                        dma_dir == DMA_FROM_DEVICE,
-                                        1, /* force */
-                                        buf->pages, NULL);
-               if (n_pages != buf->n_pages)
-                       goto fail_get_user_pages;
-
-               buf->vaddr = vm_map_ram(buf->pages, buf->n_pages, -1,
+               buf->vaddr = vm_map_ram(frame_vector_pages(vec), n_pages, -1,
                                        PAGE_KERNEL);
-               if (!buf->vaddr)
-                       goto fail_get_user_pages;
        }
 
+       if (!buf->vaddr)
+               goto fail_map;
        buf->vaddr += offset;
        return buf;
 
-fail_get_user_pages:
-       pr_debug("get_user_pages requested/got: %d/%d]\n", n_pages,
-                buf->n_pages);
-       while (--n_pages >= 0)
-               put_page(buf->pages[n_pages]);
-       kfree(buf->pages);
-
-fail_pages_array_alloc:
+fail_map:
+       vb2_destroy_framevec(vec);
+fail_pfnvec_create:
        kfree(buf);
 
        return NULL;
@@ -143,20 +124,21 @@ static void vb2_vmalloc_put_userptr(void *buf_priv)
        struct vb2_vmalloc_buf *buf = buf_priv;
        unsigned long vaddr = (unsigned long)buf->vaddr & PAGE_MASK;
        unsigned int i;
+       struct page **pages;
+       unsigned int n_pages;
 
-       if (buf->pages) {
+       if (!buf->vec->is_pfns) {
+               n_pages = frame_vector_count(buf->vec);
+               pages = frame_vector_pages(buf->vec);
                if (vaddr)
-                       vm_unmap_ram((void *)vaddr, buf->n_pages);
-               for (i = 0; i < buf->n_pages; ++i) {
-                       if (buf->dma_dir == DMA_FROM_DEVICE)
-                               set_page_dirty_lock(buf->pages[i]);
-                       put_page(buf->pages[i]);
-               }
-               kfree(buf->pages);
+                       vm_unmap_ram((void *)vaddr, n_pages);
+               if (buf->dma_dir == DMA_FROM_DEVICE)
+                       for (i = 0; i < n_pages; i++)
+                               set_page_dirty_lock(pages[i]);
        } else {
-               vb2_put_vma(buf->vma);
                iounmap((__force void __iomem *)buf->vaddr);
        }
+       vb2_destroy_framevec(buf->vec);
        kfree(buf);
 }
 
index fda728e3c27d000d952bfccc8c0850dcd649aa68..91c08f6f0dc96dbb7474d3349f62b5d3f723fe80 100644 (file)
@@ -20,6 +20,7 @@
 #include <linux/shrinker.h>
 #include <linux/resource.h>
 #include <linux/page_ext.h>
+#include <linux/err.h>
 
 struct mempolicy;
 struct anon_vma;
@@ -1214,6 +1215,49 @@ long get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm,
                    int write, int force, struct page **pages);
 int get_user_pages_fast(unsigned long start, int nr_pages, int write,
                        struct page **pages);
+
+/* Container for pinned pfns / pages */
+struct frame_vector {
+       unsigned int nr_allocated;      /* Number of frames we have space for */
+       unsigned int nr_frames; /* Number of frames stored in ptrs array */
+       bool got_ref;           /* Did we pin pages by getting page ref? */
+       bool is_pfns;           /* Does array contain pages or pfns? */
+       void *ptrs[0];          /* Array of pinned pfns / pages. Use
+                                * pfns_vector_pages() or pfns_vector_pfns()
+                                * for access */
+};
+
+struct frame_vector *frame_vector_create(unsigned int nr_frames);
+void frame_vector_destroy(struct frame_vector *vec);
+int get_vaddr_frames(unsigned long start, unsigned int nr_pfns,
+                    bool write, bool force, struct frame_vector *vec);
+void put_vaddr_frames(struct frame_vector *vec);
+int frame_vector_to_pages(struct frame_vector *vec);
+void frame_vector_to_pfns(struct frame_vector *vec);
+
+static inline unsigned int frame_vector_count(struct frame_vector *vec)
+{
+       return vec->nr_frames;
+}
+
+static inline struct page **frame_vector_pages(struct frame_vector *vec)
+{
+       if (vec->is_pfns) {
+               int err = frame_vector_to_pages(vec);
+
+               if (err)
+                       return ERR_PTR(err);
+       }
+       return (struct page **)(vec->ptrs);
+}
+
+static inline unsigned long *frame_vector_pfns(struct frame_vector *vec)
+{
+       if (!vec->is_pfns)
+               frame_vector_to_pfns(vec);
+       return (unsigned long *)(vec->ptrs);
+}
+
 struct kvec;
 int get_kernel_pages(const struct kvec *iov, int nr_pages, int write,
                        struct page **pages);
index 9f36641a67810f80a4387b2a706d61318841e2af..6513c7ec3116f1722f490fac8abf9d1f39d39ceb 100644 (file)
@@ -15,6 +15,7 @@
 #define _MEDIA_VIDEOBUF2_MEMOPS_H
 
 #include <media/videobuf2-core.h>
+#include <linux/mm.h>
 
 /**
  * struct vb2_vmarea_handler - common vma refcount tracking handler
@@ -31,11 +32,9 @@ struct vb2_vmarea_handler {
 
 extern const struct vm_operations_struct vb2_common_vm_ops;
 
-int vb2_get_contig_userptr(unsigned long vaddr, unsigned long size,
-                          struct vm_area_struct **res_vma, dma_addr_t *res_pa);
-
-struct vm_area_struct *vb2_get_vma(struct vm_area_struct *vma);
-void vb2_put_vma(struct vm_area_struct *vma);
-
+struct frame_vector *vb2_create_framevec(unsigned long start,
+                                        unsigned long length,
+                                        bool write);
+void vb2_destroy_framevec(struct frame_vector *vec);
 
 #endif
index 6413d027c0b2ea18acb3c9c1a35149ce7af4bd2c..0d9fdcd01e479d87a45cb487db54e8c1fff27883 100644 (file)
@@ -677,3 +677,6 @@ config ZONE_DEVICE
          mapping in an O_DIRECT operation, among other things.
 
          If FS_DAX is enabled, then say Y.
+
+config FRAME_VECTOR
+       bool
index 56f8eed73f1a6f658d90d156b5b4f2ddd0030eae..2ed43191fc3bf78f46f111e88fa9d5a01b8c661a 100644 (file)
@@ -80,3 +80,4 @@ obj-$(CONFIG_PAGE_EXTENSION) += page_ext.o
 obj-$(CONFIG_CMA_DEBUGFS) += cma_debug.o
 obj-$(CONFIG_USERFAULTFD) += userfaultfd.o
 obj-$(CONFIG_IDLE_PAGE_TRACKING) += page_idle.o
+obj-$(CONFIG_FRAME_VECTOR) += frame_vector.o
diff --git a/mm/frame_vector.c b/mm/frame_vector.c
new file mode 100644 (file)
index 0000000..cdabcb9
--- /dev/null
@@ -0,0 +1,230 @@
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.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);
+       kvfree(vec);
+}
+EXPORT_SYMBOL(frame_vector_destroy);