gpu: nvgpu: Use perf table only VBIOS supports it

We retrieve perf table from VBIOS only if respective HAL op is
implemented. Later in code we unconditionally dereference the pointer
which can lead to NULL pointer access.

Fix by early aborting creation of devinit tables if the perf VBIOS
getter is missing.

Change-Id: If48aa6dac724056dd1feb2ef520e343736d4db85
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-on: http://git-master/r/1279223
GVS: Gerrit_Virtual_Submit
Reviewed-by: Thomas Fleury <tfleury@nvidia.com>

1 files changed, 14 insertions, 13 deletions

diff --git a/drivers/gpu/nvgpu/perf/vfe_var.c b/drivers/gpu/nvgpu/perf/vfe_var.c
index 4f8dc83b..f4c3f276 100644
--- a/drivers/gpu/nvgpu/perf/vfe_var.c
+++ b/drivers/gpu/nvgpu/perf/vfe_var.c
@@ -182,20 +182,21 @@ u32 dev_init_get_vfield_info(struct gk20a *g,
         u8 *psegmentcount = NULL;
         u32 status = 0;
 
-        if (g->ops.bios.get_perf_table_ptrs) {
-                vfieldregtableptr = (u8 *)g->ops.bios.get_perf_table_ptrs(g,
-                                g->bios.virt_token, VP_FIELD_REGISTER);
-                if (vfieldregtableptr == NULL) {
-                        status = -EINVAL;
-                        goto done;
-                }
+        if (!g->ops.bios.get_perf_table_ptrs)
+                return -EINVAL;
 
-                vfieldtableptr = (u8 *)g->ops.bios.get_perf_table_ptrs(g,
-                                g->bios.virt_token, VP_FIELD_TABLE);
-                if (vfieldtableptr == NULL) {
-                        status = -EINVAL;
-                        goto done;
-                }
+        vfieldregtableptr = (u8 *)g->ops.bios.get_perf_table_ptrs(g,
+                        g->bios.virt_token, VP_FIELD_REGISTER);
+        if (vfieldregtableptr == NULL) {
+                status = -EINVAL;
+                goto done;
+        }
+
+        vfieldtableptr = (u8 *)g->ops.bios.get_perf_table_ptrs(g,
+                        g->bios.virt_token, VP_FIELD_TABLE);
+        if (vfieldtableptr == NULL) {
+                status = -EINVAL;
+                goto done;
         }
 
         memcpy(&vregheader, vfieldregtableptr, VFIELD_REG_HEADER_SIZE);