pata_sil680: Do our own exec_command posting

Use our own mmio area to avoid PCI posting. This avoids the rather slow
paranoid implementation in the default handler.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 26 insertions, 4 deletions

diff --git a/drivers/ata/pata_sil680.c b/drivers/ata/pata_sil680.c
index c6c589c23ffc..43faf106f647 100644
--- a/drivers/ata/pata_sil680.c
+++ b/drivers/ata/pata_sil680.c
@@ -190,15 +190,37 @@ static void sil680_set_dmamode(struct ata_port *ap, struct ata_device *adev)
         pci_write_config_word(pdev, ua, ultra);
 }
 
+/**
+ *      sil680_sff_exec_command - issue ATA command to host controller
+ *      @ap: port to which command is being issued
+ *      @tf: ATA taskfile register set
+ *
+ *      Issues ATA command, with proper synchronization with interrupt
+ *      handler / other threads. Use our MMIO space for PCI posting to avoid
+ *      a hideously slow cycle all the way to the device.
+ *
+ *      LOCKING:
+ *      spin_lock_irqsave(host lock)
+ */
+void sil680_sff_exec_command(struct ata_port *ap,
+                                        const struct ata_taskfile *tf)
+{
+        DPRINTK("ata%u: cmd 0x%X\n", ap->print_id, tf->command);
+        iowrite8(tf->command, ap->ioaddr.command_addr);
+        ioread8(ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
+}
+
 static struct scsi_host_template sil680_sht = {
         ATA_BMDMA_SHT(DRV_NAME),
 };
 
+
 static struct ata_port_operations sil680_port_ops = {
-        .inherits       = &ata_bmdma32_port_ops,
-        .cable_detect   = sil680_cable_detect,
-        .set_piomode    = sil680_set_piomode,
-        .set_dmamode    = sil680_set_dmamode,
+        .inherits               = &ata_bmdma32_port_ops,
+        .sff_exec_command       = sil680_sff_exec_command,
+        .cable_detect           = sil680_cable_detect,
+        .set_piomode            = sil680_set_piomode,
+        .set_dmamode            = sil680_set_dmamode,
 };
 
 /**