virtio/s390: add indirection to indicators access

This will come in handy soon when we pull out the indicators from
virtio_ccw_device to a memory area that is shared with the hypervisor
(in particular for protected virtualization guests).

Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Michael Mueller <mimu@linux.ibm.com>
Tested-by: Michael Mueller <mimu@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c
index 1da7430..e96a8cc 100644 (file)
--- a/drivers/s390/virtio/virtio_ccw.c
+++ b/drivers/s390/virtio/virtio_ccw.c
@@ -68,6 +68,16 @@ struct virtio_ccw_device {
        void *airq_info;
 };
 
+static inline unsigned long *indicators(struct virtio_ccw_device *vcdev)
+{
+       return &vcdev->indicators;
+}
+
+static inline unsigned long *indicators2(struct virtio_ccw_device *vcdev)
+{
+       return &vcdev->indicators2;
+}
+
 struct vq_info_block_legacy {
        __u64 queue;
        __u32 align;
@@ -338,17 +348,17 @@ static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
                ccw->cda = (__u32)(unsigned long) thinint_area;
        } else {
                /* payload is the address of the indicators */
-               indicatorp = kmalloc(sizeof(&vcdev->indicators),
+               indicatorp = kmalloc(sizeof(indicators(vcdev)),
                                     GFP_DMA | GFP_KERNEL);
                if (!indicatorp)
                        return;
                *indicatorp = 0;
                ccw->cmd_code = CCW_CMD_SET_IND;
-               ccw->count = sizeof(&vcdev->indicators);
+               ccw->count = sizeof(indicators(vcdev));
                ccw->cda = (__u32)(unsigned long) indicatorp;
        }
        /* Deregister indicators from host. */
-       vcdev->indicators = 0;
+       *indicators(vcdev) = 0;
        ccw->flags = 0;
        ret = ccw_io_helper(vcdev, ccw,
                            vcdev->is_thinint ?
@@ -657,10 +667,10 @@ static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
         * We need a data area under 2G to communicate. Our payload is
         * the address of the indicators.
        */
-       indicatorp = kmalloc(sizeof(&vcdev->indicators), GFP_DMA | GFP_KERNEL);
+       indicatorp = kmalloc(sizeof(indicators(vcdev)), GFP_DMA | GFP_KERNEL);
        if (!indicatorp)
                goto out;
-       *indicatorp = (unsigned long) &vcdev->indicators;
+       *indicatorp = (unsigned long) indicators(vcdev);
        if (vcdev->is_thinint) {
                ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
                if (ret)
@@ -669,21 +679,21 @@ static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
        }
        if (!vcdev->is_thinint) {
                /* Register queue indicators with host. */
-               vcdev->indicators = 0;
+               *indicators(vcdev) = 0;
                ccw->cmd_code = CCW_CMD_SET_IND;
                ccw->flags = 0;
-               ccw->count = sizeof(&vcdev->indicators);
+               ccw->count = sizeof(indicators(vcdev));
                ccw->cda = (__u32)(unsigned long) indicatorp;
                ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
                if (ret)
                        goto out;
        }
        /* Register indicators2 with host for config changes */
-       *indicatorp = (unsigned long) &vcdev->indicators2;
-       vcdev->indicators2 = 0;
+       *indicatorp = (unsigned long) indicators2(vcdev);
+       *indicators2(vcdev) = 0;
        ccw->cmd_code = CCW_CMD_SET_CONF_IND;
        ccw->flags = 0;
-       ccw->count = sizeof(&vcdev->indicators2);
+       ccw->count = sizeof(indicators2(vcdev));
        ccw->cda = (__u32)(unsigned long) indicatorp;
        ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
        if (ret)
@@ -1093,17 +1103,17 @@ static void virtio_ccw_int_handler(struct ccw_device *cdev,
                        vcdev->err = -EIO;
        }
        virtio_ccw_check_activity(vcdev, activity);
-       for_each_set_bit(i, &vcdev->indicators,
-                        sizeof(vcdev->indicators) * BITS_PER_BYTE) {
+       for_each_set_bit(i, indicators(vcdev),
+                        sizeof(*indicators(vcdev)) * BITS_PER_BYTE) {
                /* The bit clear must happen before the vring kick. */
-               clear_bit(i, &vcdev->indicators);
+               clear_bit(i, indicators(vcdev));
                barrier();
                vq = virtio_ccw_vq_by_ind(vcdev, i);
                vring_interrupt(0, vq);
        }
-       if (test_bit(0, &vcdev->indicators2)) {
+       if (test_bit(0, indicators2(vcdev))) {
                virtio_config_changed(&vcdev->vdev);
-               clear_bit(0, &vcdev->indicators2);
+               clear_bit(0, indicators2(vcdev));
        }
 }