staging: ion: dup sg_table when map_dma_buffer

[firefly-linux-kernel-4.4.55.git] / drivers / staging / android / ion / ion.c

diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c
index 13c0972669c0d779d85e59f4ab93e582f46ae46f..5083289504abc0202cd882ef2de67dfd22d63bc7 100644 (file)
--- a/drivers/staging/android/ion/ion.c
+++ b/drivers/staging/android/ion/ion.c
@@ -1178,13 +1178,57 @@ static struct sg_table *ion_map_dma_buf(struct dma_buf_attachment *attachment,
 {
        struct dma_buf *dmabuf = attachment->dmabuf;
        struct ion_buffer *buffer = dmabuf->priv;
+       int nr_pages = PAGE_ALIGN(buffer->size) / PAGE_SIZE;
+       struct sg_table *table = buffer->sg_table;
+       struct scatterlist *sg;
+       struct sg_table *sgt;
+       int ret, i;
 
        ion_buffer_sync_for_device(buffer, attachment->dev, direction);
-       if (!dma_map_sg(attachment->dev, buffer->sg_table->sgl,
-                       buffer->sg_table->nents, direction))
+       sgt = kmalloc(sizeof(*sgt), GFP_KERNEL);
+       if (!sgt)
                return ERR_PTR(-ENOMEM);
 
-       return buffer->sg_table;
+       if (!buffer->pages) {
+               int j, k = 0;
+
+               buffer->pages = vmalloc(sizeof(struct page *) * nr_pages);
+               if (!buffer->pages) {
+                       ret = -ENOMEM;
+                       goto err_free_sgt;
+               }
+
+               for_each_sg(table->sgl, sg, table->nents, i) {
+                       struct page *page = sg_page(sg);
+
+                       for (j = 0; j < sg->length / PAGE_SIZE; j++)
+                               buffer->pages[k++] = page++;
+               }
+       }
+
+       ret = sg_alloc_table_from_pages(sgt, buffer->pages, nr_pages, 0,
+                               nr_pages << PAGE_SHIFT, GFP_KERNEL);
+       if (ret)
+               goto err_free_sgt;
+
+       for_each_sg(sgt->sgl, sg, sgt->nents, i) {
+               sg_dma_address(sg) = sg_phys(sg);
+               sg_dma_len(sg) = sg->length;
+       }
+
+       if (!dma_map_sg(attachment->dev, sgt->sgl,
+                       sgt->nents, direction)) {
+               ret = -ENOMEM;
+               goto err_free_sg_table;
+       }
+
+       return sgt;
+
+err_free_sg_table:
+       sg_free_table(sgt);
+err_free_sgt:
+       kfree(sgt);
+       return ERR_PTR(ret);
 }
 
 static void ion_unmap_dma_buf(struct dma_buf_attachment *attachment,
@@ -1192,6 +1236,8 @@ static void ion_unmap_dma_buf(struct dma_buf_attachment *attachment,
                              enum dma_data_direction direction)
 {
        dma_unmap_sg(attachment->dev, table->sgl, table->nents, direction);
+       sg_free_table(table);
+       kfree(table);
 }
 
 void ion_pages_sync_for_device(struct device *dev, struct page *page,