[PATCH 2/2] drm/etnaviv: use CMA area to compute linear window offset if possible

[Lucas Stach <l.stach@pengutronix.de>]

The dma_required_mask might overestimate the memory size, or might not match
up with the CMA area placement for other reasons. Get the information about
CMA area placement directly from CMA where it is available, but keep the
dma_required_mask as an approximate fallback for architectures where CMA is
not available.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
---
 drivers/gpu/drm/etnaviv/etnaviv_gpu.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
index 72d01e873160..b144f1bbbb3c 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
@@ -4,7 +4,9 @@
  */
 
 #include <linux/clk.h>
+#include <linux/cma.h>
 #include <linux/component.h>
+#include <linux/dma-contiguous.h>
 #include <linux/dma-fence.h>
 #include <linux/moduleparam.h>
 #include <linux/of_device.h>
@@ -724,11 +726,18 @@ int etnaviv_gpu_init(struct etnaviv_gpu *gpu)
 	 */
 	if (!(gpu->identity.features & chipFeatures_PIPE_3D) ||
 	    (gpu->identity.minor_features0 & chipMinorFeatures0_MC20)) {
-		u32 dma_mask = (u32)dma_get_required_mask(gpu->dev);
-		if (dma_mask < PHYS_OFFSET + SZ_2G)
+		struct cma *cma = dev_get_cma_area(gpu->dev);
+		phys_addr_t end_mask;
+
+		if (cma)
+			end_mask = cma_get_base(cma) - 1 + cma_get_size(cma);
+		else
+			end_mask = dma_get_required_mask(gpu->dev);
+
+		if (end_mask < PHYS_OFFSET + SZ_2G)
 			gpu->memory_base = PHYS_OFFSET;
 		else
-			gpu->memory_base = dma_mask - SZ_2G + 1;
+			gpu->memory_base = end_mask - SZ_2G + 1;
 	} else if (PHYS_OFFSET >= SZ_2G) {
 		dev_info(gpu->dev, "Need to move linear window on MC1.0, disabling TS\n");
 		gpu->memory_base = PHYS_OFFSET;
-- 
2.20.1