[PATCH RFC 054/111] staging: etnaviv: move scatterlist creation to etnaviv_gem_get_pages()

[Lucas Stach]

From: Russell King <rmk+ker...@arm.linux.org.uk>

Move the scatterlist creation from etnaviv_gem_shmem_get_pages() into
etnaviv_gem_get_pages() as we always want a scatterlist internally for
the IOMMU code.  It makes little sense to have each get_pages() method
re-implement this code.

However, we still allow a get_pages() method to override this by doing
their own initialisation of the etnaviv_obj->sgt pointer.

Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
---
 drivers/staging/etnaviv/etnaviv_gem.c | 47 +++++++++++++++++++++--------------
 1 file changed, 28 insertions(+), 19 deletions(-)

diff --git a/drivers/staging/etnaviv/etnaviv_gem.c 
b/drivers/staging/etnaviv/etnaviv_gem.c
index ab7c6db4ec10..ad8fa71ea920 100644
--- a/drivers/staging/etnaviv/etnaviv_gem.c
+++ b/drivers/staging/etnaviv/etnaviv_gem.c
@@ -27,37 +27,21 @@
 static int etnaviv_gem_shmem_get_pages(struct etnaviv_gem_object *etnaviv_obj)
 {
        struct drm_device *dev = etnaviv_obj->base.dev;
-       struct page **p;
-       int npages = etnaviv_obj->base.size >> PAGE_SHIFT;
+       struct page **p = drm_gem_get_pages(&etnaviv_obj->base);

-       p = drm_gem_get_pages(&etnaviv_obj->base);
        if (IS_ERR(p)) {
                dev_err(dev->dev, "could not get pages: %ld\n", PTR_ERR(p));
                return PTR_ERR(p);
        }

-       etnaviv_obj->sgt = drm_prime_pages_to_sg(p, npages);
-       if (IS_ERR(etnaviv_obj->sgt)) {
-               dev_err(dev->dev, "failed to allocate sgt\n");
-               drm_gem_put_pages(&etnaviv_obj->base, p, false, false);
-               return PTR_ERR(p);
-       }
-
        etnaviv_obj->pages = p;

-       /* For non-cached buffers, ensure the new pages are clean
-        * because display controller, GPU, etc. are not coherent:
-        */
-       if (etnaviv_obj->flags & (ETNA_BO_WC|ETNA_BO_CACHED))
-               dma_map_sg(dev->dev, etnaviv_obj->sgt->sgl,
-                          etnaviv_obj->sgt->nents, DMA_BIDIRECTIONAL);
-
        return 0;
 }

 static void put_pages(struct etnaviv_gem_object *etnaviv_obj)
 {
-       if (etnaviv_obj->pages) {
+       if (etnaviv_obj->sgt) {
                struct drm_device *dev = etnaviv_obj->base.dev;

                /*
@@ -81,7 +65,9 @@ static void put_pages(struct etnaviv_gem_object *etnaviv_obj)
                                     DMA_BIDIRECTIONAL);
                sg_free_table(etnaviv_obj->sgt);
                kfree(etnaviv_obj->sgt);
-
+               etnaviv_obj->sgt = NULL;
+       }
+       if (etnaviv_obj->pages) {
                drm_gem_put_pages(&etnaviv_obj->base, etnaviv_obj->pages,
                                  true, false);

@@ -99,6 +85,29 @@ struct page **etnaviv_gem_get_pages(struct 
etnaviv_gem_object *etnaviv_obj)
                        return ERR_PTR(ret);
        }

+       if (!etnaviv_obj->sgt) {
+               struct drm_device *dev = etnaviv_obj->base.dev;
+               int npages = etnaviv_obj->base.size >> PAGE_SHIFT;
+               struct sg_table *sgt;
+
+               sgt = drm_prime_pages_to_sg(etnaviv_obj->pages, npages);
+               if (IS_ERR(sgt)) {
+                       dev_err(dev->dev, "failed to allocate sgt: %ld\n",
+                               PTR_ERR(sgt));
+                       return ERR_CAST(sgt);
+               }
+
+               etnaviv_obj->sgt = sgt;
+
+               /*
+                * For non-cached buffers, ensure the new pages are clean
+                * because display controller, GPU, etc. are not coherent.
+                */
+               if (etnaviv_obj->flags & (ETNA_BO_WC|ETNA_BO_CACHED))
+                       dma_map_sg(dev->dev, etnaviv_obj->sgt->sgl,
+                                  etnaviv_obj->sgt->nents, DMA_BIDIRECTIONAL);
+       }
+
        return etnaviv_obj->pages;
 }

-- 
2.1.4