+#define CELL_FACING_FRONT 0
+#define CELL_FACING_BACK 1
+
+struct cell_fence
+{
+ /** There's a 16-byte status qword per SPU */
+ volatile uint status[CELL_MAX_SPUS][4];
+};
+
+#ifdef __SPU__
+typedef vector unsigned int opcode_t;
+#else
+typedef unsigned int opcode_t[4];
+#endif
+
+/**
+ * Fence command sent to SPUs. In response, the SPUs will write
+ * CELL_FENCE_STATUS_SIGNALLED back to the fence status word in main memory.
+ */
+struct cell_command_fence
+{
+ opcode_t opcode; /**< CELL_CMD_FENCE */
+ struct cell_fence *fence;
+ uint32_t pad_[3];
+};