[Intel-gfx] [PATCH] drm/shmem-helper: Switch to vmf_insert_pfn

[Daniel Vetter]

We want to stop gup, which isn't the case if we use vmf_insert_page
and VM_MIXEDMAP, because that does not set pte_special.

v2: With this shmem gem helpers now definitely need CONFIG_MMU (0day)

v3: add more depends on MMU. For usb drivers this is a bit awkward,
but really it's correct: To be able to provide a contig mapping of
buffers to userspace on !MMU platforms we'd need to use the cma
helpers for these drivers on those platforms. As-is this wont work.

Also not exactly sure why vm_insert_page doesn't go boom, because that
definitely wont fly in practice since the pages are non-contig to
begin with.

Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Cc: Maxime Ripard <mripard at kernel.org>
Cc: Thomas Zimmermann <tzimmermann at suse.de>
Cc: David Airlie <airlied at linux.ie>
Cc: Daniel Vetter <daniel at ffwll.ch>
---
 drivers/gpu/drm/Kconfig                | 2 +-
 drivers/gpu/drm/drm_gem_shmem_helper.c | 4 ++--
 drivers/gpu/drm/gud/Kconfig            | 2 +-
 drivers/gpu/drm/tiny/Kconfig           | 4 ++--
 drivers/gpu/drm/udl/Kconfig            | 1 +
 5 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 56a55a6e6239..9c21527b791f 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -206,7 +206,7 @@ config DRM_KMS_CMA_HELPER
 
 config DRM_GEM_SHMEM_HELPER
 	bool
-	depends on DRM
+	depends on DRM && MMU
 	help
 	  Choose this if you need the GEM shmem helper functions
 
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 6d625cee7a6a..11edd54f0580 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -542,7 +542,7 @@ static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf)
 	} else {
 		page = shmem->pages[page_offset];
 
-		ret = vmf_insert_page(vma, vmf->address, page);
+		ret = vmf_insert_pfn(vma, vmf->address, page_to_pfn(page));
 	}
 
 	mutex_unlock(&shmem->pages_lock);
@@ -612,7 +612,7 @@ int drm_gem_shmem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
 		return ret;
 	}
 
-	vma->vm_flags |= VM_MIXEDMAP | VM_DONTEXPAND;
+	vma->vm_flags |= VM_PFNMAP | VM_DONTEXPAND;
 	vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
 	if (shmem->map_wc)
 		vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
diff --git a/drivers/gpu/drm/gud/Kconfig b/drivers/gpu/drm/gud/Kconfig
index 1c8601bf4d91..9c1e61f9eec3 100644
--- a/drivers/gpu/drm/gud/Kconfig
+++ b/drivers/gpu/drm/gud/Kconfig
@@ -2,7 +2,7 @@
 
 config DRM_GUD
 	tristate "GUD USB Display"
-	depends on DRM && USB
+	depends on DRM && USB && MMU
 	select LZ4_COMPRESS
 	select DRM_KMS_HELPER
 	select DRM_GEM_SHMEM_HELPER
diff --git a/drivers/gpu/drm/tiny/Kconfig b/drivers/gpu/drm/tiny/Kconfig
index d46f95d9196d..a15f57ace9e7 100644
--- a/drivers/gpu/drm/tiny/Kconfig
+++ b/drivers/gpu/drm/tiny/Kconfig
@@ -31,7 +31,7 @@ config DRM_CIRRUS_QEMU
 
 config DRM_GM12U320
 	tristate "GM12U320 driver for USB projectors"
-	depends on DRM && USB
+	depends on DRM && USB && MMU
 	select DRM_KMS_HELPER
 	select DRM_GEM_SHMEM_HELPER
 	help
@@ -40,7 +40,7 @@ config DRM_GM12U320
 
 config DRM_SIMPLEDRM
 	tristate "Simple framebuffer driver"
-	depends on DRM
+	depends on DRM && MMU
 	select DRM_GEM_SHMEM_HELPER
 	select DRM_KMS_HELPER
 	help
diff --git a/drivers/gpu/drm/udl/Kconfig b/drivers/gpu/drm/udl/Kconfig
index 1f497d8f1ae5..c744175c6992 100644
--- a/drivers/gpu/drm/udl/Kconfig
+++ b/drivers/gpu/drm/udl/Kconfig
@@ -4,6 +4,7 @@ config DRM_UDL
 	depends on DRM
 	depends on USB
 	depends on USB_ARCH_HAS_HCD
+	depends on MMU
 	select DRM_GEM_SHMEM_HELPER
 	select DRM_KMS_HELPER
 	help
-- 
2.31.0