[media] media: vb2: Convert vb2_dc_get_userptr() to use frame vector

Convert vb2_dc_get_userptr() to use frame vector infrastructure. When we
are doing that there's no need to allocate page array and some code can
be simplified.

Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
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>

1 files changed, 34 insertions, 178 deletions

diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c
index c548ce425701..2397ceb1dc6b 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c
@@ -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();
@@ -604,75 +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);
 
-        down_read(&current->mm->mmap_sem);
-        /* 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) {
-                        up_read(&current->mm->mmap_sem);
-                        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;
         }
-        up_read(&current->mm->mmap_sem);
 
         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.
@@ -694,8 +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;
 
@@ -704,25 +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]);
-
-        down_read(&current->mm->mmap_sem);
-fail_vma:
-        vb2_put_vma(buf->vma);
-
-fail_pages:
-        up_read(&current->mm->mmap_sem);
-        kfree(pages); /* kfree is NULL-proof */
+fail_pfnvec:
+        vb2_destroy_framevec(vec);
 
 fail_buf:
         kfree(buf);