[PATCH 2/2] drm/msm: use drm_cache when available

Rob Clark
2019-08-05T21:21:42Z

From: Rob Clark <robdclark@chromium.org>

For a long time drm/msm had been abusing dma_map_* or dma_sync_* to
clean pages for buffers with uncached/writecombine CPU mmap'ings.

But drm/msm is managing it's own iommu domains, and really doesn't want
the additional functionality provided by various DMA API ops.

Let's just cut the abstraction and use drm_cache where possible.

Signed-off-by: Rob Clark <robdclark@chromium.org>
---
drivers/gpu/drm/msm/msm_gem.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index 8cf6362e64bf..af19ef20d0d5 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -9,6 +9,8 @@
#include <linux/dma-buf.h>
#include <linux/pfn_t.h>

+#include <drm/drm_cache.h>
+
#include "msm_drv.h"
#include "msm_fence.h"
#include "msm_gem.h"
@@ -48,6 +50,7 @@ static bool use_pages(struct drm_gem_object *obj)

static void sync_for_device(struct msm_gem_object *msm_obj)
{
+#if !defined(HAS_DRM_CACHE)
struct device *dev = msm_obj->base.dev->dev;

if (get_dma_ops(dev)) {
@@ -57,10 +60,14 @@ static void sync_for_device(struct msm_gem_object *msm_obj)
dma_map_sg(dev, msm_obj->sgt->sgl,
msm_obj->sgt->nents, DMA_BIDIRECTIONAL);
}
+#else
+ drm_clflush_sg(msm_obj->sgt);
+#endif
}

static void sync_for_cpu(struct msm_gem_object *msm_obj)
{
+#if !defined(HAS_DRM_CACHE)
struct device *dev = msm_obj->base.dev->dev;

if (get_dma_ops(dev)) {
@@ -70,6 +77,7 @@ static void sync_for_cpu(struct msm_gem_object *msm_obj)
dma_unmap_sg(dev, msm_obj->sgt->sgl,
msm_obj->sgt->nents, DMA_BIDIRECTIONAL);
}
+#endif
}

/* allocate pages from VRAM carveout, used when no IOMMU: */
--
2.21.0