[PATCH] drm/msm: Disallow relocs on a6xx+

From: Rob Clark
Date: Thu Aug 03 2023 - 14:32:58 EST


From: Rob Clark <robdclark@xxxxxxxxxxxx>

Mesa stopped using these pretty early in a6xx bringup[1]. Take advantage
of this to disallow some legacy UABI.

[1] https://gitlab.freedesktop.org/mesa/mesa/-/commit/7ef722861b691ce99be3827ed05f8c0ddf2cd66e

Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
Acked-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
---
drivers/gpu/drm/msm/adreno/adreno_gpu.c | 2 ++
drivers/gpu/drm/msm/msm_gem_submit.c | 10 ++++++++++
drivers/gpu/drm/msm/msm_gpu.h | 9 +++++++++
3 files changed, 21 insertions(+)

diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
index ba35c2a87021..695cce82d914 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
@@ -1078,6 +1078,8 @@ int adreno_gpu_init(struct drm_device *drm, struct platform_device *pdev,
adreno_gpu->info = config->info;
adreno_gpu->chip_id = config->chip_id;

+ gpu->allow_relocs = config->info->family < ADRENO_6XX_GEN1;
+
/* Only handle the core clock when GMU is not in use (or is absent). */
if (adreno_has_gmu_wrapper(adreno_gpu) ||
adreno_gpu->info->family < ADRENO_6XX_GEN1) {
diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
index 63c96416e183..3b908f9f5493 100644
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -882,6 +882,16 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
if (submit->valid)
continue;

+ if (!gpu->allow_relocs) {
+ if (submit->cmd[i].nr_relocs) {
+ DRM_ERROR("relocs not allowed\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ continue;
+ }
+
ret = submit_reloc(submit, msm_obj, submit->cmd[i].offset * 4,
submit->cmd[i].nr_relocs, submit->cmd[i].relocs);
if (ret)
diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
index 7a4fa1b8655b..4252e3839fbc 100644
--- a/drivers/gpu/drm/msm/msm_gpu.h
+++ b/drivers/gpu/drm/msm/msm_gpu.h
@@ -285,6 +285,15 @@ struct msm_gpu {
/* True if the hardware supports expanded apriv (a650 and newer) */
bool hw_apriv;

+ /**
+ * @allow_relocs: allow relocs in SUBMIT ioctl
+ *
+ * Mesa won't use relocs for driver version 1.4.0 and later. This
+ * switch-over happened early enough in mesa a6xx bringup that we
+ * can disallow relocs for a6xx and newer.
+ */
+ bool allow_relocs;
+
struct thermal_cooling_device *cooling;
};

--
2.41.0