-/**
- * sn_migrate - SN-specific task migration actions
- * @task: Task being migrated to new CPU
- *
- * SN2 PIO writes from separate CPUs are not guaranteed to arrive in order.
- * Context switching user threads which have memory-mapped MMIO may cause
- * PIOs to issue from seperate CPUs, thus the PIO writes must be drained
- * from the previous CPU's Shub before execution resumes on the new CPU.
- */
-void sn_migrate(struct task_struct *task)
-{
- pda_t *last_pda = pdacpu(task_thread_info(task)->last_cpu);
- volatile unsigned long *adr = last_pda->pio_write_status_addr;
- unsigned long val = last_pda->pio_write_status_val;
-
- /* Drain PIO writes from old CPU's Shub */
- while (unlikely((*adr & SH_PIO_WRITE_STATUS_PENDING_WRITE_COUNT_MASK)
- != val))
- cpu_relax();
-}
-