virtio: use size-based config accessors.

This lets the transport do endian conversion if necessary, and insulates
the drivers from the difference.

Most drivers can use the simple helpers virtio_cread() and virtio_cwrite().

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 89245b5..6b66252 100644 (file)
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -456,18 +456,15 @@ static int virtblk_ioctl(struct block_device *bdev, fmode_t mode,
 static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)
 {
        struct virtio_blk *vblk = bd->bd_disk->private_data;
-       struct virtio_blk_geometry vgeo;
-       int err;
 
        /* see if the host passed in geometry config */
-       err = virtio_config_val(vblk->vdev, VIRTIO_BLK_F_GEOMETRY,
-                               offsetof(struct virtio_blk_config, geometry),
-                               &vgeo);
-
-       if (!err) {
-               geo->heads = vgeo.heads;
-               geo->sectors = vgeo.sectors;
-               geo->cylinders = vgeo.cylinders;
+       if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) {
+               virtio_cread(vblk->vdev, struct virtio_blk_config,
+                            geometry.cylinders, &geo->cylinders);
+               virtio_cread(vblk->vdev, struct virtio_blk_config,
+                            geometry.heads, &geo->heads);
+               virtio_cread(vblk->vdev, struct virtio_blk_config,
+                            geometry.sectors, &geo->sectors);
        } else {
                /* some standard values, similar to sd */
                geo->heads = 1 << 6;
@@ -529,8 +526,7 @@ static void virtblk_config_changed_work(struct work_struct *work)
                goto done;
 
        /* Host must always specify the capacity. */
-       vdev->config->get(vdev, offsetof(struct virtio_blk_config, capacity),
-                         &capacity, sizeof(capacity));
+       virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity);
 
        /* If capacity is too big, truncate with warning. */
        if ((sector_t)capacity != capacity) {
@@ -608,9 +604,9 @@ static int virtblk_get_cache_mode(struct virtio_device *vdev)
        u8 writeback;
        int err;
 
-       err = virtio_config_val(vdev, VIRTIO_BLK_F_CONFIG_WCE,
-                               offsetof(struct virtio_blk_config, wce),
-                               &writeback);
+       err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE,
+                                  struct virtio_blk_config, wce,
+                                  &writeback);
        if (err)
                writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_WCE);
 
@@ -642,7 +638,6 @@ virtblk_cache_type_store(struct device *dev, struct device_attribute *attr,
        struct virtio_blk *vblk = disk->private_data;
        struct virtio_device *vdev = vblk->vdev;
        int i;
-       u8 writeback;
 
        BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE));
        for (i = ARRAY_SIZE(virtblk_cache_types); --i >= 0; )
@@ -652,11 +647,7 @@ virtblk_cache_type_store(struct device *dev, struct device_attribute *attr,
        if (i < 0)
                return -EINVAL;
 
-       writeback = i;
-       vdev->config->set(vdev,
-                         offsetof(struct virtio_blk_config, wce),
-                         &writeback, sizeof(writeback));
-
+       virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i);
        virtblk_update_cache_mode(vdev);
        return count;
 }
@@ -699,9 +690,9 @@ static int virtblk_probe(struct virtio_device *vdev)
        index = err;
 
        /* We need to know how many segments before we allocate. */
-       err = virtio_config_val(vdev, VIRTIO_BLK_F_SEG_MAX,
-                               offsetof(struct virtio_blk_config, seg_max),
-                               &sg_elems);
+       err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX,
+                                  struct virtio_blk_config, seg_max,
+                                  &sg_elems);
 
        /* We need at least one SG element, whatever they say. */
        if (err || !sg_elems)
@@ -772,8 +763,7 @@ static int virtblk_probe(struct virtio_device *vdev)
                set_disk_ro(vblk->disk, 1);
 
        /* Host must always specify the capacity. */
-       vdev->config->get(vdev, offsetof(struct virtio_blk_config, capacity),
-                         &cap, sizeof(cap));
+       virtio_cread(vdev, struct virtio_blk_config, capacity, &cap);
 
        /* If capacity is too big, truncate with warning. */
        if ((sector_t)cap != cap) {
@@ -794,46 +784,45 @@ static int virtblk_probe(struct virtio_device *vdev)
 
        /* Host can optionally specify maximum segment size and number of
         * segments. */
-       err = virtio_config_val(vdev, VIRTIO_BLK_F_SIZE_MAX,
-                               offsetof(struct virtio_blk_config, size_max),
-                               &v);
+       err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX,
+                                  struct virtio_blk_config, size_max, &v);
        if (!err)
                blk_queue_max_segment_size(q, v);
        else
                blk_queue_max_segment_size(q, -1U);
 
        /* Host can optionally specify the block size of the device */
-       err = virtio_config_val(vdev, VIRTIO_BLK_F_BLK_SIZE,
-                               offsetof(struct virtio_blk_config, blk_size),
-                               &blk_size);
+       err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
+                                  struct virtio_blk_config, blk_size,
+                                  &blk_size);
        if (!err)
                blk_queue_logical_block_size(q, blk_size);
        else
                blk_size = queue_logical_block_size(q);
 
        /* Use topology information if available */
-       err = virtio_config_val(vdev, VIRTIO_BLK_F_TOPOLOGY,
-                       offsetof(struct virtio_blk_config, physical_block_exp),
-                       &physical_block_exp);
+       err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
+                                  struct virtio_blk_config, physical_block_exp,
+                                  &physical_block_exp);
        if (!err && physical_block_exp)
                blk_queue_physical_block_size(q,
                                blk_size * (1 << physical_block_exp));
 
-       err = virtio_config_val(vdev, VIRTIO_BLK_F_TOPOLOGY,
-                       offsetof(struct virtio_blk_config, alignment_offset),
-                       &alignment_offset);
+       err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
+                                  struct virtio_blk_config, alignment_offset,
+                                  &alignment_offset);
        if (!err && alignment_offset)
                blk_queue_alignment_offset(q, blk_size * alignment_offset);
 
-       err = virtio_config_val(vdev, VIRTIO_BLK_F_TOPOLOGY,
-                       offsetof(struct virtio_blk_config, min_io_size),
-                       &min_io_size);
+       err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
+                                  struct virtio_blk_config, min_io_size,
+                                  &min_io_size);
        if (!err && min_io_size)
                blk_queue_io_min(q, blk_size * min_io_size);
 
-       err = virtio_config_val(vdev, VIRTIO_BLK_F_TOPOLOGY,
-                       offsetof(struct virtio_blk_config, opt_io_size),
-                       &opt_io_size);
+       err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
+                                  struct virtio_blk_config, opt_io_size,
+                                  &opt_io_size);
        if (!err && opt_io_size)
                blk_queue_io_opt(q, blk_size * opt_io_size);
 

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 862fd54..2a8d9a7 100644 (file)
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -1837,12 +1837,8 @@ static void config_intr(struct virtio_device *vdev)
                struct port *port;
                u16 rows, cols;
 
-               vdev->config->get(vdev,
-                                 offsetof(struct virtio_console_config, cols),
-                                 &cols, sizeof(u16));
-               vdev->config->get(vdev,
-                                 offsetof(struct virtio_console_config, rows),
-                                 &rows, sizeof(u16));
+               virtio_cread(vdev, struct virtio_console_config, cols, &cols);
+               virtio_cread(vdev, struct virtio_console_config, rows, &rows);
 
                port = find_port_by_id(portdev, 0);
                set_console_size(port, rows, cols);
@@ -2014,10 +2010,9 @@ static int virtcons_probe(struct virtio_device *vdev)
 
        /* Don't test MULTIPORT at all if we're rproc: not a valid feature! */
        if (!is_rproc_serial(vdev) &&
-           virtio_config_val(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
-                                 offsetof(struct virtio_console_config,
-                                          max_nr_ports),
-                                 &portdev->config.max_nr_ports) == 0) {
+           virtio_cread_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
+                                struct virtio_console_config, max_nr_ports,
+                                &portdev->config.max_nr_ports) == 0) {
                multiport = true;
        }
 

diff --git a/drivers/net/caif/caif_virtio.c b/drivers/net/caif/caif_virtio.c
index b9ed128..9856086 100644 (file)
--- a/drivers/net/caif/caif_virtio.c
+++ b/drivers/net/caif/caif_virtio.c
@@ -686,18 +686,19 @@ static int cfv_probe(struct virtio_device *vdev)
                goto err;
 
        /* Get the CAIF configuration from virtio config space, if available */
-#define GET_VIRTIO_CONFIG_OPS(_v, _var, _f) \
-       ((_v)->config->get(_v, offsetof(struct virtio_caif_transf_config, _f), \
-                          &_var, \
-                          FIELD_SIZEOF(struct virtio_caif_transf_config, _f)))
-
        if (vdev->config->get) {
-               GET_VIRTIO_CONFIG_OPS(vdev, cfv->tx_hr, headroom);
-               GET_VIRTIO_CONFIG_OPS(vdev, cfv->rx_hr, headroom);
-               GET_VIRTIO_CONFIG_OPS(vdev, cfv->tx_tr, tailroom);
-               GET_VIRTIO_CONFIG_OPS(vdev, cfv->rx_tr, tailroom);
-               GET_VIRTIO_CONFIG_OPS(vdev, cfv->mtu, mtu);
-               GET_VIRTIO_CONFIG_OPS(vdev, cfv->mru, mtu);
+               virtio_cread(vdev, struct virtio_caif_transf_config, headroom,
+                            &cfv->tx_hr);
+               virtio_cread(vdev, struct virtio_caif_transf_config, headroom,
+                            &cfv->rx_hr);
+               virtio_cread(vdev, struct virtio_caif_transf_config, tailroom,
+                            &cfv->tx_tr);
+               virtio_cread(vdev, struct virtio_caif_transf_config, tailroom,
+                            &cfv->rx_tr);
+               virtio_cread(vdev, struct virtio_caif_transf_config, mtu,
+                            &cfv->mtu);
+               virtio_cread(vdev, struct virtio_caif_transf_config, mtu,
+                            &cfv->mru);
        } else {
                cfv->tx_hr = CFV_DEF_HEADROOM;
                cfv->rx_hr = CFV_DEF_HEADROOM;

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 2ad3d96..ee02271 100644 (file)
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -852,8 +852,13 @@ static int virtnet_set_mac_address(struct net_device *dev, void *p)
                        return -EINVAL;
                }
        } else if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
-               vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
-                                 addr->sa_data, dev->addr_len);
+               unsigned int i;
+
+               /* Naturally, this has an atomicity problem. */
+               for (i = 0; i < dev->addr_len; i++)
+                       virtio_cwrite8(vdev,
+                                      offsetof(struct virtio_net_config, mac) +
+                                      i, addr->sa_data[i]);
        }
 
        eth_commit_mac_addr_change(dev, p);
@@ -1266,9 +1271,8 @@ static void virtnet_config_changed_work(struct work_struct *work)
        if (!vi->config_enable)
                goto done;
 
-       if (virtio_config_val(vi->vdev, VIRTIO_NET_F_STATUS,
-                             offsetof(struct virtio_net_config, status),
-                             &v) < 0)
+       if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
+                                struct virtio_net_config, status, &v) < 0)
                goto done;
 
        if (v & VIRTIO_NET_S_ANNOUNCE) {
@@ -1490,9 +1494,9 @@ static int virtnet_probe(struct virtio_device *vdev)
        u16 max_queue_pairs;
 
        /* Find if host supports multiqueue virtio_net device */
-       err = virtio_config_val(vdev, VIRTIO_NET_F_MQ,
-                               offsetof(struct virtio_net_config,
-                               max_virtqueue_pairs), &max_queue_pairs);
+       err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
+                                  struct virtio_net_config,
+                                  max_virtqueue_pairs, &max_queue_pairs);
 
        /* We need at least 2 queue's */
        if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
@@ -1544,9 +1548,11 @@ static int virtnet_probe(struct virtio_device *vdev)
        dev->vlan_features = dev->features;
 
        /* Configuration may specify what MAC to use.  Otherwise random. */
-       if (virtio_config_val_len(vdev, VIRTIO_NET_F_MAC,
-                                 offsetof(struct virtio_net_config, mac),
-                                 dev->dev_addr, dev->addr_len) < 0)
+       if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
+               virtio_cread_bytes(vdev,
+                                  offsetof(struct virtio_net_config, mac),
+                                  dev->dev_addr, dev->addr_len);
+       else
                eth_hw_addr_random(dev);
 
        /* Set up our device-specific information */

diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index 2a11039..e6bb235 100644 (file)
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -710,19 +710,15 @@ static struct scsi_host_template virtscsi_host_template_multi = {
 #define virtscsi_config_get(vdev, fld) \
        ({ \
                typeof(((struct virtio_scsi_config *)0)->fld) __val; \
-               vdev->config->get(vdev, \
-                                 offsetof(struct virtio_scsi_config, fld), \
-                                 &__val, sizeof(__val)); \
+               virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \
                __val; \
        })
 
 #define virtscsi_config_set(vdev, fld, val) \
-       (void)({ \
+       do { \
                typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \
-               vdev->config->set(vdev, \
-                                 offsetof(struct virtio_scsi_config, fld), \
-                                 &__val, sizeof(__val)); \
-       })
+               virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \
+       } while(0)
 
 static void __virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity)
 {

diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index d6f6816..c444654 100644 (file)
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -275,9 +275,8 @@ static inline s64 towards_target(struct virtio_balloon *vb)
        __le32 v;
        s64 target;
 
-       vb->vdev->config->get(vb->vdev,
-                             offsetof(struct virtio_balloon_config, num_pages),
-                             &v, sizeof(v));
+       virtio_cread(vb->vdev, struct virtio_balloon_config, num_pages, &v);
+
        target = le32_to_cpu(v);
        return target - vb->num_pages;
 }
@@ -286,9 +285,8 @@ static void update_balloon_size(struct virtio_balloon *vb)
 {
        __le32 actual = cpu_to_le32(vb->num_pages);
 
-       vb->vdev->config->set(vb->vdev,
-                             offsetof(struct virtio_balloon_config, actual),
-                             &actual, sizeof(actual));
+       virtio_cwrite(vb->vdev, struct virtio_balloon_config, num_pages,
+                     &actual);
 }
 
 static int balloon(void *_vballoon)

diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index 990afab..9c5a1aa 100644 (file)
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -544,9 +544,7 @@ static int p9_virtio_probe(struct virtio_device *vdev)
 
        chan->inuse = false;
        if (virtio_has_feature(vdev, VIRTIO_9P_MOUNT_TAG)) {
-               vdev->config->get(vdev,
-                               offsetof(struct virtio_9p_config, tag_len),
-                               &tag_len, sizeof(tag_len));
+               virtio_cread(vdev, struct virtio_9p_config, tag_len, &tag_len);
        } else {
                err = -EINVAL;
                goto out_free_vq;
@@ -556,8 +554,9 @@ static int p9_virtio_probe(struct virtio_device *vdev)
                err = -ENOMEM;
                goto out_free_vq;
        }
-       vdev->config->get(vdev, offsetof(struct virtio_9p_config, tag),
-                       tag, tag_len);
+
+       virtio_cread_bytes(vdev, offsetof(struct virtio_9p_config, tag),
+                          tag, tag_len);
        chan->tag = tag;
        chan->tag_len = tag_len;
        err = sysfs_create_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr);