drm/etnaviv: reinstate MMUv1 command buffer window check

The switch to per-process address spaces erroneously dropped the check
which validated that the command buffer is mapped through the linear
apperture as required by the hardware. This turned a system
misconfiguration with a helpful error message into a very hard to
debug issue. Reinstate the check at the appropriate location.

Fixes: 17e4660ae3d7 (drm/etnaviv: implement per-process address spaces on MMUv2)
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Guido Günther <agx@sigxcpu.org>

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_mmu.c b/drivers/gpu/drm/etnaviv/etnaviv_mmu.c
index 35ebae6..3607d34 100644 (file)
--- a/drivers/gpu/drm/etnaviv/etnaviv_mmu.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_mmu.c
@@ -328,12 +328,23 @@ etnaviv_iommu_context_init(struct etnaviv_iommu_global *global,
 
        ret = etnaviv_cmdbuf_suballoc_map(suballoc, ctx, &ctx->cmdbuf_mapping,
                                          global->memory_base);
-       if (ret) {
-               global->ops->free(ctx);
-               return NULL;
+       if (ret)
+               goto out_free;
+
+       if (global->version == ETNAVIV_IOMMU_V1 &&
+           ctx->cmdbuf_mapping.iova > 0x80000000) {
+               dev_err(global->dev,
+                       "command buffer outside valid memory window\n");
+               goto out_unmap;
        }
 
        return ctx;
+
+out_unmap:
+       etnaviv_cmdbuf_suballoc_unmap(ctx, &ctx->cmdbuf_mapping);
+out_free:
+       global->ops->free(ctx);
+       return NULL;
 }
 
 void etnaviv_iommu_restore(struct etnaviv_gpu *gpu,