[RFC PATCH 5/6] drm/gma500: Propagate SGX MMU setup and GEM pin failures

[Gabriel Gama <operatingsystemsdepression@gmail.com>]

Check the GEM GPU address and perform transactional MMU insertion before
changing cache attributes or publishing the GTT mapping. On failure,
release temporary pages without publishing a pin and return the error.

Propagate stolen-memory mapping failures through probe cleanup before
installing a hardware context. Existing cache-attribute error handling
is unchanged. This depends on the preceding rollback fix.

Signed-off-by: Gabriel Gama <operatingsystemsdepression@gmail.com>

---
 drivers/gpu/drm/gma500/gem.c     | 19 ++++++++++++++-----
 drivers/gpu/drm/gma500/psb_drv.c |  2 ++
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/gma500/gem.c b/drivers/gpu/drm/gma500/gem.c
index fa5d3f137..c79713e26 100644
--- a/drivers/gpu/drm/gma500/gem.c
+++ b/drivers/gpu/drm/gma500/gem.c
@@ -32,7 +32,7 @@ int psb_gem_pin(struct psb_gem_object *pobj)
 	struct drm_gem_object *obj = &pobj->base;
 	struct drm_device *dev = obj->dev;
 	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
-	u32 gpu_base = dev_priv->gtt.gatt_start;
+	u64 gpu_address = (u64)dev_priv->gtt.gatt_start + pobj->offset;
 	struct page **pages;
 	unsigned int npages;
 	int ret;
@@ -44,6 +44,11 @@ int psb_gem_pin(struct psb_gem_object *pobj)
 	if (pobj->in_gart || pobj->stolen)
 		goto out; /* already mapped */
 
+	if (gpu_address >= BIT_ULL(32)) {
+		ret = -ERANGE;
+		goto err_dma_resv_unlock;
+	}
+
 	pages = drm_gem_get_pages(obj);
 	if (IS_ERR(pages)) {
 		ret = PTR_ERR(pages);
@@ -52,12 +57,14 @@ int psb_gem_pin(struct psb_gem_object *pobj)
 
 	npages = obj->size / PAGE_SIZE;
 
-	set_pages_array_wc(pages, npages);
+	ret = psb_mmu_insert_pages(psb_mmu_get_default_pd(dev_priv->mmu),
+				   pages, gpu_address, npages, 0, 0,
+				   PSB_MMU_CACHED_MEMORY);
+	if (ret)
+		goto err_put_pages;
 
+	set_pages_array_wc(pages, npages);
 	psb_gtt_insert_pages(dev_priv, &pobj->resource, pages);
-	psb_mmu_insert_pages(psb_mmu_get_default_pd(dev_priv->mmu), pages,
-			     (gpu_base + pobj->offset), npages, 0, 0,
-			     PSB_MMU_CACHED_MEMORY);
 
 	pobj->pages = pages;
 
@@ -67,6 +74,8 @@ int psb_gem_pin(struct psb_gem_object *pobj)
 
 	return 0;
 
+err_put_pages:
+	drm_gem_put_pages(obj, pages, false, false);
 err_dma_resv_unlock:
 	dma_resv_unlock(obj->resv);
 	return ret;
diff --git a/drivers/gpu/drm/gma500/psb_drv.c b/drivers/gpu/drm/gma500/psb_drv.c
index d17cb5b4a..d942f7264 100644
--- a/drivers/gpu/drm/gma500/psb_drv.c
+++ b/drivers/gpu/drm/gma500/psb_drv.c
@@ -354,6 +354,8 @@ static int psb_driver_load(struct drm_device *dev, unsigned long flags)
 					  dev_priv->stolen_base >> PAGE_SHIFT,
 					  pg->gatt_start,
 					  pg->stolen_size >> PAGE_SHIFT, 0);
+	if (ret)
+		goto out_err;
 
 	psb_mmu_set_pd_context(psb_mmu_get_default_pd(dev_priv->mmu), 0);
 	psb_mmu_set_pd_context(dev_priv->pf_pd, 1);