linux-kernel - [PATCH v2 3/5] drm/msm: call dma_direct

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Message-Id: <20201106163437.30836-4-jonathan@marek.ca>
Date:   Fri,  6 Nov 2020 11:34:32 -0500
From:   Jonathan Marek <jonathan@...ek.ca>
To:     freedreno@...ts.freedesktop.org
Cc:     Rob Clark <robdclark@...il.com>, Sean Paul <sean@...rly.run>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        linux-arm-msm@...r.kernel.org (open list:DRM DRIVER FOR MSM ADRENO GPU),
        dri-devel@...ts.freedesktop.org (open list:DRM DRIVER FOR MSM ADRENO
        GPU), linux-kernel@...r.kernel.org (open list)
Subject: [PATCH v2 3/5] drm/msm: call dma_direct_bypass()

Always use direct dma ops and no swiotlb.

Note: arm-smmu-qcom already avoids creating iommu dma ops, but not
everything uses arm-smmu-qcom and this also sets the dma mask.

Signed-off-by: Jonathan Marek <jonathan@...ek.ca>
---
 drivers/gpu/drm/msm/Kconfig   | 1 +
 drivers/gpu/drm/msm/msm_drv.c | 8 +++++---
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/msm/Kconfig b/drivers/gpu/drm/msm/Kconfig
index e5816b498494..07c50405970a 100644
--- a/drivers/gpu/drm/msm/Kconfig
+++ b/drivers/gpu/drm/msm/Kconfig
@@ -20,6 +20,7 @@ config DRM_MSM
 	select SND_SOC_HDMI_CODEC if SND_SOC
 	select SYNC_FILE
 	select PM_OPP
+	select DMA_OPS_BYPASS
 	help
 	  DRM/KMS driver for MSM/snapdragon.
 
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 49685571dc0e..bae48afca82e 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -6,6 +6,7 @@
  */
 
 #include <linux/dma-mapping.h>
+#include <linux/dma-direct.h>
 #include <linux/kthread.h>
 #include <linux/uaccess.h>
 #include <uapi/linux/sched/types.h>
@@ -1288,10 +1289,11 @@ static int msm_pdev_probe(struct platform_device *pdev)
 	if (ret)
 		goto fail;
 
-	/* on all devices that I am aware of, iommu's which can map
-	 * any address the cpu can see are used:
+	/* always use direct dma ops and no swiotlb
+	 * note: arm-smmu-qcom already avoids creating iommu dma ops, but
+	 * not everything uses arm-smmu-qcom and this also sets the dma mask
 	 */
-	ret = dma_set_mask_and_coherent(&pdev->dev, ~0);
+	ret = dma_direct_bypass(&pdev->dev);
 	if (ret)
 		goto fail;
 
-- 
2.26.1