Merge tag 'drm-misc-next-2019-03-21' of git://anongit.freedesktop.org/drm/drm-misc into drm-next

drm-misc-next for 5.2:

UAPI Changes:
- Add Colorspace connector property (Uma)
- fourcc: Several new YUV formats from ARM (Brian & Ayan)
- fourcc: Fix merge conflicts between new formats above and Swati's that
  went in via topic/hdr-formats-2019-03-07 branch (Maarten)

Cross-subsystem Changes:
- Typed component support via topic/component-typed-2019-02-11 (Maxime/Daniel)

Core Changes:
- Improve component helper documentation (Daniel)
- Avoid calling drm_dev_unregister() twice on unplugged devices (Noralf)
- Add device managed (devm) drm_device init function (Noralf)
- Graduate TINYDRM_MODE to DRM_SIMPLE_MODE in core (Noralf)
- Move MIPI/DSI rate control params computation into core from i915 (David)
- Add support for shmem backed gem objects (Noralf)

Driver Changes:
- various: Use of_node_name_eq for node name comparisons (Rob Herring)
- sun4i: Add DSI burst mode support (Konstantin)
- panel: Add Ronbo RB070D30 MIPI/DSI panel support (Konstantin)
- virtio: A few prime improvements (Gerd)
- tinydrm: Remove tinydrm_device (Noralf)
- vc4: Add load tracker to driver to detect underflow in atomic check (Boris)
- vboxvideo: Move it out of staging \o/ (Hans)
- v3d: Add support for V3D v4.2 (Eric)

Cc: Konstantin Sudakov <k.sudakov@integrasources.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Uma Shankar <uma.shankar@intel.com>
Cc: Noralf Trønnes <noralf@tronnes.org>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: David Francis <David.Francis@amd.com>
Cc: Boris Brezillon <boris.brezillon@bootlin.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Brian Starkey <brian.starkey@arm.com>
Cc: Ayan Kumar Halder <ayan.halder@arm.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

From: Sean Paul <sean@poorly.run>
Link: https://patchwork.freedesktop.org/patch/msgid/20190321170805.GA50145@art_vandelay

1 files changed, 16 insertions, 3 deletions

diff --git a/drivers/gpu/drm/drm_memory.c b/drivers/gpu/drm/drm_memory.c
index 40c4349cb939..8dbcdc77f6bf 100644
--- a/drivers/gpu/drm/drm_memory.c
+++ b/drivers/gpu/drm/drm_memory.c
@@ -35,6 +35,7 @@
 
 #include <linux/highmem.h>
 #include <linux/export.h>
+#include <xen/xen.h>
 #include <drm/drmP.h>
 #include "drm_legacy.h"
 
@@ -150,15 +151,27 @@ void drm_legacy_ioremapfree(struct drm_local_map *map, struct drm_device *dev)
 }
 EXPORT_SYMBOL(drm_legacy_ioremapfree);
 
-u64 drm_get_max_iomem(void)
+bool drm_need_swiotlb(int dma_bits)
 {
 	struct resource *tmp;
 	resource_size_t max_iomem = 0;
 
+	/*
+	 * Xen paravirtual hosts require swiotlb regardless of requested dma
+	 * transfer size.
+	 *
+	 * NOTE: Really, what it requires is use of the dma_alloc_coherent
+	 *       allocator used in ttm_dma_populate() instead of
+	 *       ttm_populate_and_map_pages(), which bounce buffers so much in
+	 *       Xen it leads to swiotlb buffer exhaustion.
+	 */
+	if (xen_pv_domain())
+		return true;
+
 	for (tmp = iomem_resource.child; tmp; tmp = tmp->sibling) {
 		max_iomem = max(max_iomem,  tmp->end);
 	}
 
-	return max_iomem;
+	return max_iomem > ((u64)1 << dma_bits);
 }
-EXPORT_SYMBOL(drm_get_max_iomem);
+EXPORT_SYMBOL(drm_need_swiotlb);