GEN8_CSB_ENTRIES
if (read >= GEN8_CSB_ENTRIES)
if (write >= GEN8_CSB_ENTRIES)
write += GEN8_CSB_ENTRIES;
idx = ++read % GEN8_CSB_ENTRIES;
GEN8_CSB_ENTRIES - 1);
execlists->csb_write_reset = GEN8_CSB_ENTRIES - 1;
if (++head == GEN8_CSB_ENTRIES)