[PATCH v4 10/11] drm/msm/A6xx: Enable preemption for A750

[Antonino Maniscalco]

Initialize with 4 rings to enable preemption.

For now only on A750 as other targets require testing.

Add the "preemption_enabled" module parameter to override this for other
A7xx targets.

Signed-off-by: Antonino Maniscalco <antomani103 at gmail.com>
Tested-by: Neil Armstrong <neil.armstrong at linaro.org> # on SM8650-QRD
---
 drivers/gpu/drm/msm/adreno/a6xx_catalog.c | 3 ++-
 drivers/gpu/drm/msm/adreno/a6xx_gpu.c     | 6 +++++-
 drivers/gpu/drm/msm/adreno/adreno_gpu.h   | 1 +
 drivers/gpu/drm/msm/msm_drv.c             | 4 ++++
 4 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_catalog.c b/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
index 316f23ca9167..0e3041b29419 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
@@ -1240,7 +1240,8 @@ static const struct adreno_info a7xx_gpus[] = {
 		.gmem = 3 * SZ_1M,
 		.inactive_period = DRM_MSM_INACTIVE_PERIOD,
 		.quirks = ADRENO_QUIRK_HAS_CACHED_COHERENT |
-			  ADRENO_QUIRK_HAS_HW_APRIV,
+			  ADRENO_QUIRK_HAS_HW_APRIV |
+			  ADRENO_QUIRK_PREEMPTION,
 		.init = a6xx_gpu_init,
 		.zapfw = "gen70900_zap.mbn",
 		.a6xx = &(const struct a6xx_info) {
diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
index edbcb6d229ba..4760f9469613 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
@@ -2529,6 +2529,7 @@ struct msm_gpu *a6xx_gpu_init(struct drm_device *dev)
 	struct a6xx_gpu *a6xx_gpu;
 	struct adreno_gpu *adreno_gpu;
 	struct msm_gpu *gpu;
+	extern int enable_preemption;
 	bool is_a7xx;
 	int ret;
 
@@ -2567,7 +2568,10 @@ struct msm_gpu *a6xx_gpu_init(struct drm_device *dev)
 		return ERR_PTR(ret);
 	}
 
-	if (is_a7xx)
+	if ((enable_preemption == 1) || (enable_preemption == -1 &&
+	    (config->info->quirks & ADRENO_QUIRK_PREEMPTION)))
+		ret = adreno_gpu_init(dev, pdev, adreno_gpu, &funcs_a7xx, 4);
+	else if (is_a7xx)
 		ret = adreno_gpu_init(dev, pdev, adreno_gpu, &funcs_a7xx, 1);
 	else if (adreno_has_gmu_wrapper(adreno_gpu))
 		ret = adreno_gpu_init(dev, pdev, adreno_gpu, &funcs_gmuwrapper, 1);
diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.h b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
index 87098567483b..d1cd53f05de6 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.h
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
@@ -56,6 +56,7 @@ enum adreno_family {
 #define ADRENO_QUIRK_LMLOADKILL_DISABLE		BIT(2)
 #define ADRENO_QUIRK_HAS_HW_APRIV		BIT(3)
 #define ADRENO_QUIRK_HAS_CACHED_COHERENT	BIT(4)
+#define ADRENO_QUIRK_PREEMPTION			BIT(5)
 
 /* Helper for formating the chip_id in the way that userspace tools like
  * crashdec expect.
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 9c33f4e3f822..7c64b20f5e3b 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -58,6 +58,10 @@ static bool modeset = true;
 MODULE_PARM_DESC(modeset, "Use kernel modesetting [KMS] (1=on (default), 0=disable)");
 module_param(modeset, bool, 0600);
 
+int enable_preemption = -1;
+MODULE_PARM_DESC(enable_preemption, "Enable preemption (A7xx only) (1=on , 0=disable, -1=auto (default))");
+module_param(enable_preemption, int, 0600);
+
 #ifdef CONFIG_FAULT_INJECTION
 DECLARE_FAULT_ATTR(fail_gem_alloc);
 DECLARE_FAULT_ATTR(fail_gem_iova);

-- 
2.46.0