vio.c

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/* vio.c: Virtual I/O channel devices probing infrastructure.
 *
 *    Copyright (c) 2003-2005 IBM Corp.
 *     Dave Engebretsen [email protected]
 *     Santiago Leon [email protected]
 *     Hollis Blanchard <[email protected]>
 *     Stephen Rothwell
 *
 * Adapted to sparc64 by David S. Miller [email protected]
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/irq.h>
#include <linux/export.h>
#include <linux/init.h>

#include <asm/mdesc.h>
#include <asm/vio.h>

static const struct vio_device_id *vio_match_device(
    const struct vio_device_id *matches,
    const struct vio_dev *dev)
{
    const char *type, *compat;
    int len;

    type = dev->type;
    compat = dev->compat;
    len = dev->compat_len;

    while (matches->type[0] || matches->compat[0]) {
        int match = 1;
        if (matches->type[0])
            match &= !strcmp(matches->type, type);

        if (matches->compat[0]) {
            match &= len &&
                of_find_in_proplist(compat, matches->compat, len);
        }
        if (match)
            return matches;
        matches++;
    }
    return NULL;
}

static int vio_bus_match(struct device *dev, struct device_driver *drv)
{
    struct vio_dev *vio_dev = to_vio_dev(dev);
    struct vio_driver *vio_drv = to_vio_driver(drv);
    const struct vio_device_id *matches = vio_drv->id_table;

    if (!matches)
        return 0;

    return vio_match_device(matches, vio_dev) != NULL;
}

static int vio_device_probe(struct device *dev)
{
    struct vio_dev *vdev = to_vio_dev(dev);
    struct vio_driver *drv = to_vio_driver(dev->driver);
    const struct vio_device_id *id;
    int error = -ENODEV;

    if (drv->probe) {
        id = vio_match_device(drv->id_table, vdev);
        if (id)
            error = drv->probe(vdev, id);
    }

    return error;
}

static int vio_device_remove(struct device *dev)
{
    struct vio_dev *vdev = to_vio_dev(dev);
    struct vio_driver *drv = to_vio_driver(dev->driver);

    if (drv->remove)
        return drv->remove(vdev);

    return 1;
}

static ssize_t devspec_show(struct device *dev,
        struct device_attribute *attr, char *buf)
{
    struct vio_dev *vdev = to_vio_dev(dev);
    const char *str = "none";

    if (!strcmp(vdev->type, "vnet-port"))
        str = "vnet";
    else if (!strcmp(vdev->type, "vdc-port"))
        str = "vdisk";

    return sprintf(buf, "%s\n", str);
}

static ssize_t type_show(struct device *dev,
        struct device_attribute *attr, char *buf)
{
    struct vio_dev *vdev = to_vio_dev(dev);
    return sprintf(buf, "%s\n", vdev->type);
}

static struct device_attribute vio_dev_attrs[] = {
    __ATTR_RO(devspec),
    __ATTR_RO(type),
    __ATTR_NULL
};

static struct bus_type vio_bus_type = {
    .name       = "vio",
    .dev_attrs  = vio_dev_attrs,
    .match      = vio_bus_match,
    .probe      = vio_device_probe,
    .remove     = vio_device_remove,
};

int __vio_register_driver(struct vio_driver *viodrv, struct module *owner,
            const char *mod_name)
{
    viodrv->driver.bus = &vio_bus_type;
    viodrv->driver.name = viodrv->name;
    viodrv->driver.owner = owner;
    viodrv->driver.mod_name = mod_name;

    return driver_register(&viodrv->driver);
}
EXPORT_SYMBOL(__vio_register_driver);

void vio_unregister_driver(struct vio_driver *viodrv)
{
    driver_unregister(&viodrv->driver);
}
EXPORT_SYMBOL(vio_unregister_driver);

static void vio_dev_release(struct device *dev)
{
    kfree(to_vio_dev(dev));
}

static ssize_t
show_pciobppath_attr(struct device *dev, struct device_attribute *attr,
             char *buf)
{
    struct vio_dev *vdev;
    struct device_node *dp;

    vdev = to_vio_dev(dev);
    dp = vdev->dp;

    return snprintf (buf, PAGE_SIZE, "%s\n", dp->full_name);
}

static DEVICE_ATTR(obppath, S_IRUSR | S_IRGRP | S_IROTH,
           show_pciobppath_attr, NULL);

static struct device_node *cdev_node;

static struct vio_dev *root_vdev;
static u64 cdev_cfg_handle;

static void vio_fill_channel_info(struct mdesc_handle *hp, u64 mp,
                  struct vio_dev *vdev)
{
    u64 a;

    mdesc_for_each_arc(a, hp, mp, MDESC_ARC_TYPE_FWD) {
        const u64 *chan_id;
        const u64 *irq;
        u64 target;

        target = mdesc_arc_target(hp, a);

        irq = mdesc_get_property(hp, target, "tx-ino", NULL);
        if (irq)
            vdev->tx_irq = sun4v_build_virq(cdev_cfg_handle, *irq);

        irq = mdesc_get_property(hp, target, "rx-ino", NULL);
        if (irq)
            vdev->rx_irq = sun4v_build_virq(cdev_cfg_handle, *irq);

        chan_id = mdesc_get_property(hp, target, "id", NULL);
        if (chan_id)
            vdev->channel_id = *chan_id;
    }
}

static struct vio_dev *vio_create_one(struct mdesc_handle *hp, u64 mp,
                      struct device *parent)
{
    const char *type, *compat, *bus_id_name;
    struct device_node *dp;
    struct vio_dev *vdev;
    int err, tlen, clen;
    const u64 *id, *cfg_handle;
    u64 a;

    type = mdesc_get_property(hp, mp, "device-type", &tlen);
    if (!type) {
        type = mdesc_get_property(hp, mp, "name", &tlen);
        if (!type) {
            type = mdesc_node_name(hp, mp);
            tlen = strlen(type) + 1;
        }
    }
    if (tlen > VIO_MAX_TYPE_LEN) {
        printk(KERN_ERR "VIO: Type string [%s] is too long.\n",
               type);
        return NULL;
    }

    id = mdesc_get_property(hp, mp, "id", NULL);

    cfg_handle = NULL;
    mdesc_for_each_arc(a, hp, mp, MDESC_ARC_TYPE_BACK) {
        u64 target;

        target = mdesc_arc_target(hp, a);
        cfg_handle = mdesc_get_property(hp, target,
                        "cfg-handle", NULL);
        if (cfg_handle)
            break;
    }

    bus_id_name = type;
    if (!strcmp(type, "domain-services-port"))
        bus_id_name = "ds";

    /*
     * 20 char is the old driver-core name size limit, which is no more.
     * This check can probably be removed after review and possible
     * adaption of the vio users name length handling.
     */
    if (strlen(bus_id_name) >= 20 - 4) {
        printk(KERN_ERR "VIO: bus_id_name [%s] is too long.\n",
               bus_id_name);
        return NULL;
    }

    compat = mdesc_get_property(hp, mp, "device-type", &clen);
    if (!compat) {
        clen = 0;
    } else if (clen > VIO_MAX_COMPAT_LEN) {
        printk(KERN_ERR "VIO: Compat len %d for [%s] is too long.\n",
               clen, type);
        return NULL;
    }

    vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
    if (!vdev) {
        printk(KERN_ERR "VIO: Could not allocate vio_dev\n");
        return NULL;
    }

    vdev->mp = mp;
    memcpy(vdev->type, type, tlen);
    if (compat)
        memcpy(vdev->compat, compat, clen);
    else
        memset(vdev->compat, 0, sizeof(vdev->compat));
    vdev->compat_len = clen;

    vdev->channel_id = ~0UL;
    vdev->tx_irq = ~0;
    vdev->rx_irq = ~0;

    vio_fill_channel_info(hp, mp, vdev);

    if (!id) {
        dev_set_name(&vdev->dev, "%s", bus_id_name);
        vdev->dev_no = ~(u64)0;
    } else if (!cfg_handle) {
        dev_set_name(&vdev->dev, "%s-%llu", bus_id_name, *id);
        vdev->dev_no = *id;
    } else {
        dev_set_name(&vdev->dev, "%s-%llu-%llu", bus_id_name,
                 *cfg_handle, *id);
        vdev->dev_no = *cfg_handle;
    }

    vdev->dev.parent = parent;
    vdev->dev.bus = &vio_bus_type;
    vdev->dev.release = vio_dev_release;

    if (parent == NULL) {
        dp = cdev_node;
    } else if (to_vio_dev(parent) == root_vdev) {
        dp = of_get_next_child(cdev_node, NULL);
        while (dp) {
            if (!strcmp(dp->type, type))
                break;

            dp = of_get_next_child(cdev_node, dp);
        }
    } else {
        dp = to_vio_dev(parent)->dp;
    }
    vdev->dp = dp;

    printk(KERN_INFO "VIO: Adding device %s\n", dev_name(&vdev->dev));

    err = device_register(&vdev->dev);
    if (err) {
        printk(KERN_ERR "VIO: Could not register device %s, err=%d\n",
               dev_name(&vdev->dev), err);
        kfree(vdev);
        return NULL;
    }
    if (vdev->dp)
        err = sysfs_create_file(&vdev->dev.kobj,
                    &dev_attr_obppath.attr);

    return vdev;
}

static void vio_add(struct mdesc_handle *hp, u64 node)
{
    (void) vio_create_one(hp, node, &root_vdev->dev);
}

static int vio_md_node_match(struct device *dev, void *arg)
{
    struct vio_dev *vdev = to_vio_dev(dev);

    if (vdev->mp == (u64) arg)
        return 1;

    return 0;
}

static void vio_remove(struct mdesc_handle *hp, u64 node)
{
    struct device *dev;

    dev = device_find_child(&root_vdev->dev, (void *) node,
                vio_md_node_match);
    if (dev) {
        printk(KERN_INFO "VIO: Removing device %s\n", dev_name(dev));

        device_unregister(dev);
    }
}

static struct mdesc_notifier_client vio_device_notifier = {
    .add        = vio_add,
    .remove     = vio_remove,
    .node_name  = "virtual-device-port",
};

/* We are only interested in domain service ports under the
 * "domain-services" node.  On control nodes there is another port
 * under "openboot" that we should not mess with as aparently that is
 * reserved exclusively for OBP use.
 */
static void vio_add_ds(struct mdesc_handle *hp, u64 node)
{
    int found;
    u64 a;

    found = 0;
    mdesc_for_each_arc(a, hp, node, MDESC_ARC_TYPE_BACK) {
        u64 target = mdesc_arc_target(hp, a);
        const char *name = mdesc_node_name(hp, target);

        if (!strcmp(name, "domain-services")) {
            found = 1;
            break;
        }
    }

    if (found)
        (void) vio_create_one(hp, node, &root_vdev->dev);
}

static struct mdesc_notifier_client vio_ds_notifier = {
    .add        = vio_add_ds,
    .remove     = vio_remove,
    .node_name  = "domain-services-port",
};

static const char *channel_devices_node = "channel-devices";
static const char *channel_devices_compat = "SUNW,sun4v-channel-devices";
static const char *cfg_handle_prop = "cfg-handle";

static int __init vio_init(void)
{
    struct mdesc_handle *hp;
    const char *compat;
    const u64 *cfg_handle;
    int err, len;
    u64 root;

    err = bus_register(&vio_bus_type);
    if (err) {
        printk(KERN_ERR "VIO: Could not register bus type err=%d\n",
               err);
        return err;
    }

    hp = mdesc_grab();
    if (!hp)
        return 0;

    root = mdesc_node_by_name(hp, MDESC_NODE_NULL, channel_devices_node);
    if (root == MDESC_NODE_NULL) {
        printk(KERN_INFO "VIO: No channel-devices MDESC node.\n");
        mdesc_release(hp);
        return 0;
    }

    cdev_node = of_find_node_by_name(NULL, "channel-devices");
    err = -ENODEV;
    if (!cdev_node) {
        printk(KERN_INFO "VIO: No channel-devices OBP node.\n");
        goto out_release;
    }

    compat = mdesc_get_property(hp, root, "compatible", &len);
    if (!compat) {
        printk(KERN_ERR "VIO: Channel devices lacks compatible "
               "property\n");
        goto out_release;
    }
    if (!of_find_in_proplist(compat, channel_devices_compat, len)) {
        printk(KERN_ERR "VIO: Channel devices node lacks (%s) "
               "compat entry.\n", channel_devices_compat);
        goto out_release;
    }

    cfg_handle = mdesc_get_property(hp, root, cfg_handle_prop, NULL);
    if (!cfg_handle) {
        printk(KERN_ERR "VIO: Channel devices lacks %s property\n",
               cfg_handle_prop);
        goto out_release;
    }

    cdev_cfg_handle = *cfg_handle;

    root_vdev = vio_create_one(hp, root, NULL);
    err = -ENODEV;
    if (!root_vdev) {
        printk(KERN_ERR "VIO: Could not create root device.\n");
        goto out_release;
    }

    mdesc_register_notifier(&vio_device_notifier);
    mdesc_register_notifier(&vio_ds_notifier);

    mdesc_release(hp);

    return err;

out_release:
    mdesc_release(hp);
    return err;
}

postcore_initcall(vio_init);