static int tegra_drm_open(struct drm_device *drm, struct drm_file *filp)
 {
-       return 0;
+       struct tegra_drm_fpriv *fpriv;
+       int err = 0;
+
+       fpriv = kzalloc(sizeof(*fpriv), GFP_KERNEL);
+       if (!fpriv)
+               return -ENOMEM;
+
+       INIT_LIST_HEAD(&fpriv->contexts);
+       filp->driver_priv = fpriv;
+

who frees this?

+struct tegra_drm_syncpt_incr_args {
+       __u32 id;
+};

add 32-bits of padding here

+
+struct tegra_drm_syncpt_wait_args {
+       __u32 id;
+       __u32 thresh;
+       __s32 timeout;
+       __u32 value;
+};
+
+#define DRM_TEGRA_NO_TIMEOUT   (-1)
+
+struct tegra_drm_open_channel_args {
+       __u32 class;
+       void *context;

no pointers use u64, align them to 64-bits, so 32-bits of padding,

+};
+
+struct tegra_drm_get_channel_param_args {
+       void *context;
+       __u32 value;

Same padding + uint64_t for void *

+};
+
+struct tegra_drm_syncpt_incr {
+       __u32 syncpt_id;
+       __u32 syncpt_incrs;
+};
+
+struct tegra_drm_cmdbuf {
+       __u32 mem;
+       __u32 offset;
+       __u32 words;
+};

add padding

+
+struct tegra_drm_reloc {
+       __u32 cmdbuf_mem;
+       __u32 cmdbuf_offset;
+       __u32 target;
+       __u32 target_offset;
+       __u32 shift;
+};

add padding

+
+struct tegra_drm_waitchk {
+       __u32 mem;
+       __u32 offset;
+       __u32 syncpt_id;
+       __u32 thresh;
+};
+
+struct tegra_drm_submit_args {
+       void *context;
+       __u32 num_syncpt_incrs;
+       __u32 num_cmdbufs;
+       __u32 num_relocs;
+       __u32 submit_version;
+       __u32 num_waitchks;
+       __u32 waitchk_mask;
+       __u32 timeout;
+       struct tegra_drm_syncpt_incrs *syncpt_incrs;
+       struct tegra_drm_cmdbuf *cmdbufs;
+       struct tegra_drm_reloc *relocs;
+       struct tegra_drm_waitchk *waitchks;
+
+       __u32 pad[5];           /* future expansion */
+       __u32 fence;            /* Return value */
+};

lose all the pointers for 64-bit aligned uint64_t.

Probably should align all of these on __u64 and __u32 usage if possible.

i'll look at the rest of the patches, but I need to know what commands
can be submitted via this interface and what are the security
implications of it.

Dave.