+/**
+ * ata_sff_irq_status - Check if the device is busy
+ * @ap: port where the device is
+ *
+ * Determine if the port is currently busy. Uses altstatus
+ * if available in order to avoid clearing shared IRQ status
+ * when finding an IRQ source. Non ctl capable devices don't
+ * share interrupt lines fortunately for us.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ */
+static u8 ata_sff_irq_status(struct ata_port *ap)
+{
+ u8 status;
+
+ if (ap->ops->sff_check_altstatus || ap->ioaddr.altstatus_addr) {
+ status = ata_sff_altstatus(ap);
+ /* Not us: We are busy */
+ if (status & ATA_BUSY)
+ return status;
+ }
+ /* Clear INTRQ latch */
+ status = ap->ops->sff_check_status(ap);
+ return status;
+}
+
+/**
+ * ata_sff_sync - Flush writes
+ * @ap: Port to wait for.
+ *
+ * CAUTION:
+ * If we have an mmio device with no ctl and no altstatus
+ * method this will fail. No such devices are known to exist.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ */
+
+static void ata_sff_sync(struct ata_port *ap)
+{
+ if (ap->ops->sff_check_altstatus)
+ ap->ops->sff_check_altstatus(ap);
+ else if (ap->ioaddr.altstatus_addr)
+ ioread8(ap->ioaddr.altstatus_addr);
+}
+
+/**
+ * ata_sff_pause - Flush writes and wait 400nS
+ * @ap: Port to pause for.
+ *
+ * CAUTION:
+ * If we have an mmio device with no ctl and no altstatus
+ * method this will fail. No such devices are known to exist.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ */
+
+void ata_sff_pause(struct ata_port *ap)
+{
+ ata_sff_sync(ap);
+ ndelay(400);
+}
+
+/**
+ * ata_sff_dma_pause - Pause before commencing DMA
+ * @ap: Port to pause for.
+ *
+ * Perform I/O fencing and ensure sufficient cycle delays occur
+ * for the HDMA1:0 transition
+ */
+
+void ata_sff_dma_pause(struct ata_port *ap)
+{
+ if (ap->ops->sff_check_altstatus || ap->ioaddr.altstatus_addr) {
+ /* An altstatus read will cause the needed delay without
+ messing up the IRQ status */
+ ata_sff_altstatus(ap);
+ return;
+ }
+ /* There are no DMA controllers without ctl. BUG here to ensure
+ we never violate the HDMA1:0 transition timing and risk
+ corruption. */
+ BUG();
+}
+