1 files changed, 40 insertions, 12 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/channel_gk20a.c b/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
index 8ad1dcca..2ba160dd 100644
--- a/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
@@ -1790,23 +1790,51 @@ int gk20a_submit_channel_gpfifo(struct channel_gk20a *c,
         start = c->gpfifo.put;
         end = start + num_entries;
 
-        if (end > c->gpfifo.entry_num) {
-                int length0 = c->gpfifo.entry_num - start;
-                int length1 = num_entries - length0;
+        /*
+         * This WAR is in place for handling invalid simulation GPFIFO entries
+         * passed to us from userspace. This will be removed once these invalid
+         * GPFIFO entries are handled in userspace.
+         */
+        if (tegra_platform_is_linsim()) {
+                int i;
+                struct gpfifo *gpfifo_entries = c->gpfifo.mem.cpu_va;
 
-                memcpy((struct gpfifo *)c->gpfifo.mem.cpu_va + start, gpfifo,
-                       length0 * sizeof(*gpfifo));
+                for (i = 0; i < num_entries; i++) {
+                        int index = (start + i) & (c->gpfifo.entry_num - 1);
 
-                memcpy((struct gpfifo *)c->gpfifo.mem.cpu_va, gpfifo + length0,
-                       length1 * sizeof(*gpfifo));
+                        /* Copy the entry... */
+                        gpfifo_entries[index].entry0 = gpfifo[i].entry0;
+                        gpfifo_entries[index].entry1 = gpfifo[i].entry1;
 
-                trace_write_pushbuffer_range(c, gpfifo, length0);
-                trace_write_pushbuffer_range(c, gpfifo + length0, length1);
+                        /*
+                         * And here's the WAR: if the length is 0 clear the
+                         * opcode field (bottom 8 bits).
+                         */
+                        if (!pbdma_gp_entry1_length_v(gpfifo[i].entry1))
+                                gpfifo_entries[index].entry1 &= ~0xff;
+
+                        trace_write_pushbuffer_range(c, gpfifo, num_entries);
+                }
         } else {
-                memcpy((struct gpfifo *)c->gpfifo.mem.cpu_va + start, gpfifo,
-                       num_entries * sizeof(*gpfifo));
+                if (end > c->gpfifo.entry_num) {
+                        int length0 = c->gpfifo.entry_num - start;
+                        int length1 = num_entries - length0;
 
-                trace_write_pushbuffer_range(c, gpfifo, num_entries);
+                        memcpy((struct gpfifo *)c->gpfifo.mem.cpu_va + start,
+                               gpfifo, length0 * sizeof(*gpfifo));
+
+                        memcpy((struct gpfifo *)c->gpfifo.mem.cpu_va,
+                               gpfifo + length0, length1 * sizeof(*gpfifo));
+
+                        trace_write_pushbuffer_range(c, gpfifo, length0);
+                        trace_write_pushbuffer_range(c, gpfifo + length0,
+                                                     length1);
+                } else {
+                        memcpy((struct gpfifo *)c->gpfifo.mem.cpu_va + start,
+                               gpfifo, num_entries * sizeof(*gpfifo));
+
+                        trace_write_pushbuffer_range(c, gpfifo, num_entries);
+                }
         }
         c->gpfifo.put = (c->gpfifo.put + num_entries) &
                 (c->gpfifo.entry_num - 1);