ibmvfc: Add support for collaborative memory overcommit

Adds support to the ibmvfc driver for collaborative memory overcommit.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
index eb702b9..c4a7c06 100644 (file)
--- a/drivers/scsi/ibmvscsi/ibmvfc.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc.c
@@ -3819,6 +3819,20 @@ static int ibmvfc_remove(struct vio_dev *vdev)
        return 0;
 }
 
+/**
+ * ibmvfc_get_desired_dma - Calculate DMA resources needed by the driver
+ * @vdev:      vio device struct
+ *
+ * Return value:
+ *     Number of bytes the driver will need to DMA map at the same time in
+ *     order to perform well.
+ */
+static unsigned long ibmvfc_get_desired_dma(struct vio_dev *vdev)
+{
+       unsigned long pool_dma = max_requests * sizeof(union ibmvfc_iu);
+       return pool_dma + ((512 * 1024) * driver_template.cmd_per_lun);
+}
+
 static struct vio_device_id ibmvfc_device_table[] __devinitdata = {
        {"fcp", "IBM,vfc-client"},
        { "", "" }
@@ -3829,6 +3843,7 @@ static struct vio_driver ibmvfc_driver = {
        .id_table = ibmvfc_device_table,
        .probe = ibmvfc_probe,
        .remove = ibmvfc_remove,
+       .get_desired_dma = ibmvfc_get_desired_dma,
        .driver = {
                .name = IBMVFC_NAME,
                .owner = THIS_MODULE,