// SPDX-License-Identifier: GPL-2.0
/* vio.c: Virtual I/O channel devices probing infrastructure.
 *
 *    Copyright (c) 2003-2005 IBM Corp.
 *     Dave Engebretsen engebret@us.ibm.com
 *     Santiago Leon santil@us.ibm.com
 *     Hollis Blanchard <hollisb@us.ibm.com>
 *     Stephen Rothwell
 *
 * Adapted to sparc64 by David S. Miller davem@davemloft.net
 */

#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_hotplug(struct device *dev, struct kobj_uevent_env *env)
{
        const struct vio_dev *vio_dev = to_vio_dev(dev);

        add_uevent_var(env, "MODALIAS=vio:T%sS%s", vio_dev->type, vio_dev->compat);
        return 0;
}

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;

        if (!drv->probe)
                return -ENODEV;

        id = vio_match_device(drv->id_table, vdev);
        if (!id)
                return -ENODEV;

        /* alloc irqs (unless the driver specified not to) */
        if (!drv->no_irq) {
                if (vdev->tx_irq == 0 && vdev->tx_ino != ~0UL)
                        vdev->tx_irq = sun4v_build_virq(vdev->cdev_handle,
                                                        vdev->tx_ino);

                if (vdev->rx_irq == 0 && vdev->rx_ino != ~0UL)
                        vdev->rx_irq = sun4v_build_virq(vdev->cdev_handle,
                                                        vdev->rx_ino);
        }

        return drv->probe(vdev, id);
}

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) {
                /*
                 * Ideally, we would remove/deallocate tx/rx virqs
                 * here - however, there are currently no support
                 * routines to do so at the moment. TBD
                 */

                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 DEVICE_ATTR_RO(devspec);

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 DEVICE_ATTR_RO(type);

static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
                             char *buf)
{
        const struct vio_dev *vdev = to_vio_dev(dev);

        return sprintf(buf, "vio:T%sS%s\n", vdev->type, vdev->compat);
}
static DEVICE_ATTR_RO(modalias);

static struct attribute *vio_dev_attrs[] = {
        &dev_attr_devspec.attr,
        &dev_attr_type.attr,
        &dev_attr_modalias.attr,
        NULL,
 };
ATTRIBUTE_GROUPS(vio_dev);

static struct bus_type vio_bus_type = {
        .name           = "vio",
        .dev_groups     = vio_dev_groups,
        .uevent         = vio_hotplug,
        .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, "%pOF\n", dp);
}

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 const u64 *vio_cfg_handle(struct mdesc_handle *hp, u64 node)
{
        const u64 *cfg_handle = NULL;
        u64 a;

        mdesc_for_each_arc(a, hp, node, 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;
        }

        return cfg_handle;
}

/**
 * vio_vdev_node() - Find VDEV node in MD
 * @hp:  Handle to the MD
 * @vdev:  Pointer to VDEV
 *
 * Find the node in the current MD which matches the given vio_dev. This
 * must be done dynamically since the node value can change if the MD
 * is updated.
 *
 * NOTE: the MD must be locked, using mdesc_grab(), when calling this routine
 *
 * Return: The VDEV node in MDESC
 */
u64 vio_vdev_node(struct mdesc_handle *hp, struct vio_dev *vdev)
{
        u64 node;

        if (vdev == NULL)
                return MDESC_NODE_NULL;

        node = mdesc_get_node(hp, (const char *)vdev->node_name,
                              &vdev->md_node_info);

        return node;
}
EXPORT_SYMBOL(vio_vdev_node);

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

        vdev->tx_ino = ~0UL;
        vdev->rx_ino = ~0UL;
        vdev->channel_id = ~0UL;
        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_ino = *irq;

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

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

        vdev->cdev_handle = cdev_cfg_handle;
}

int vio_set_intr(unsigned long dev_ino, int state)
{
        int err;

        err = sun4v_vintr_set_valid(cdev_cfg_handle, dev_ino, state);
        return err;
}
EXPORT_SYMBOL(vio_set_intr);

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

        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 || strlen(type) >= 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 = vio_cfg_handle(hp, mp);

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

        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) {
                for_each_child_of_node(cdev_node, dp) {
                        if (of_node_is_type(dp, type))
                                break;
                }
        } else {
                dp = to_vio_dev(parent)->dp;
        }
        vdev->dp = dp;

        /*
         * node_name is NULL for the parent/channel-devices node and
         * the parent doesn't require the MD node info.
         */
        if (node_name != NULL) {
                (void) snprintf(vdev->node_name, VIO_MAX_NAME_LEN, "%s",
                                node_name);

                err = mdesc_get_node_info(hp, mp, node_name,
                                          &vdev->md_node_info);
                if (err) {
                        pr_err("VIO: Could not get MD node info %s, err=%d\n",
                               dev_name(&vdev->dev), err);
                        kfree(vdev);
                        return NULL;
                }
        }

        pr_info("VIO: Adding device %s (tx_ino = %llx, rx_ino = %llx)\n",
                dev_name(&vdev->dev), vdev->tx_ino, vdev->rx_ino);

        err = device_register(&vdev->dev);
        if (err) {
                printk(KERN_ERR "VIO: Could not register device %s, err=%d\n",
                       dev_name(&vdev->dev), err);
                put_device(&vdev->dev);
                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,
                    const char *node_name)
{
        (void) vio_create_one(hp, node, node_name, &root_vdev->dev);
}

struct vio_remove_node_data {
        struct mdesc_handle *hp;
        u64 node;
};

static int vio_md_node_match(struct device *dev, void *arg)
{
        struct vio_dev *vdev = to_vio_dev(dev);
        struct vio_remove_node_data *node_data;
        u64 node;

        node_data = (struct vio_remove_node_data *)arg;

        node = vio_vdev_node(node_data->hp, vdev);

        if (node == node_data->node)
                return 1;
        else
                return 0;
}

static void vio_remove(struct mdesc_handle *hp, u64 node, const char *node_name)
{
        struct vio_remove_node_data node_data;
        struct device *dev;

        node_data.hp = hp;
        node_data.node = node;

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

                device_unregister(dev);
                put_device(dev);
        } else {
                pr_err("VIO: %s node not found in MDESC\n", node_name);
        }
}

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,
                       const char *node_name)
{
        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, node_name, &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, 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);