Merge branch 'rdma_mmap' into rdma.git for-next

Jason Gunthorpe says:

====================
Upon review it turns out there are some long standing problems in BAR
mapping area:
 * BAR pages intended for read-only can be switched to writable via mprotect.
 * Missing use of rdma_user_mmap_io for the mlx5 clock BAR page.
 * Disassociate causes SIGBUS when touching the pages.
 * CPU pages are being mapped through to the process via remap_pfn_range
   instead of the more appropriate vm_insert_page, causing weird behaviors
   during disassociation.

This series adds the missing VM_* flag manipulation, adds faulting a zero
page for disassociation and revises the CPU page mappings to use
vm_insert_page.
====================

For dependencies this branch is based on for-rc from
git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma.git

* branch 'rdma_mmap':
  RDMA: Remove rdma_user_mmap_page
  RDMA/mlx5: Use get_zeroed_page() for clock_info
  RDMA/ucontext: Fix regression with disassociate
  RDMA/mlx5: Use rdma_user_map_io for mapping BAR pages
  RDMA/mlx5: Do not allow the user to write to the clock page

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

1 files changed, 46 insertions, 0 deletions

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.c b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
index 259b7b0de1d2..38483e9ee071 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_gem.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
@@ -241,3 +241,49 @@ err_gem_free:
 	kfree(mtk_gem);
 	return ERR_PTR(ret);
 }
+
+void *mtk_drm_gem_prime_vmap(struct drm_gem_object *obj)
+{
+	struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
+	struct sg_table *sgt;
+	struct sg_page_iter iter;
+	unsigned int npages;
+	unsigned int i = 0;
+
+	if (mtk_gem->kvaddr)
+		return mtk_gem->kvaddr;
+
+	sgt = mtk_gem_prime_get_sg_table(obj);
+	if (IS_ERR(sgt))
+		return NULL;
+
+	npages = obj->size >> PAGE_SHIFT;
+	mtk_gem->pages = kcalloc(npages, sizeof(*mtk_gem->pages), GFP_KERNEL);
+	if (!mtk_gem->pages)
+		goto out;
+
+	for_each_sg_page(sgt->sgl, &iter, sgt->orig_nents, 0) {
+		mtk_gem->pages[i++] = sg_page_iter_page(&iter);
+		if (i > npages)
+			break;
+	}
+	mtk_gem->kvaddr = vmap(mtk_gem->pages, npages, VM_MAP,
+			       pgprot_writecombine(PAGE_KERNEL));
+
+out:
+	kfree((void *)sgt);
+
+	return mtk_gem->kvaddr;
+}
+
+void mtk_drm_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
+{
+	struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
+
+	if (!mtk_gem->pages)
+		return;
+
+	vunmap(vaddr);
+	mtk_gem->kvaddr = 0;
+	kfree((void *)mtk_gem->pages);
+}