--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright � 2010 - 2015 UNISYS CORPORATION
+ * All rights reserved.
+ */
+
+#include <linux/ctype.h>
+#include <linux/debugfs.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/visorbus.h>
+#include <linux/uuid.h>
+
+#include "visorbus_private.h"
+
+static const guid_t visor_vbus_channel_guid = VISOR_VBUS_CHANNEL_GUID;
+
+/* Display string that is guaranteed to be no longer the 99 characters */
+#define LINESIZE 99
+#define POLLJIFFIES_NORMALCHANNEL 10
+
+/* stores whether bus_registration was successful */
+static bool initialized;
+static struct dentry *visorbus_debugfs_dir;
+
+/*
+ * DEVICE type attributes
+ *
+ * The modalias file will contain the guid of the device.
+ */
+static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct visor_device *vdev;
+ const guid_t *guid;
+
+ vdev = to_visor_device(dev);
+ guid = visorchannel_get_guid(vdev->visorchannel);
+ return sprintf(buf, "visorbus:%pUl\n", guid);
+}
+static DEVICE_ATTR_RO(modalias);
+
+static struct attribute *visorbus_dev_attrs[] = {
+ &dev_attr_modalias.attr,
+ NULL,
+};
+
+ATTRIBUTE_GROUPS(visorbus_dev);
+
+/* filled in with info about parent chipset driver when we register with it */
+static struct visor_vbus_deviceinfo chipset_driverinfo;
+/* filled in with info about this driver, wrt it servicing client busses */
+static struct visor_vbus_deviceinfo clientbus_driverinfo;
+
+/* list of visor_device structs, linked via .list_all */
+static LIST_HEAD(list_all_bus_instances);
+/* list of visor_device structs, linked via .list_all */
+static LIST_HEAD(list_all_device_instances);
+
+/*
+ * Generic function useful for validating any type of channel when it is
+ * received by the client that will be accessing the channel.
+ * Note that <logCtx> is only needed for callers in the EFI environment, and
+ * is used to pass the EFI_DIAG_CAPTURE_PROTOCOL needed to log messages.
+ */
+int visor_check_channel(struct channel_header *ch, struct device *dev,
+ const guid_t *expected_guid, char *chname,
+ u64 expected_min_bytes, u32 expected_version,
+ u64 expected_signature)
+{
+ if (!guid_is_null(expected_guid)) {
+ /* caller wants us to verify type GUID */
+ if (!guid_equal(&ch->chtype, expected_guid)) {
+ dev_err(dev, "Channel mismatch on channel=%s(%pUL) field=type expected=%pUL actual=%pUL\n",
+ chname, expected_guid, expected_guid,
+ &ch->chtype);
+ return 0;
+ }
+ }
+ /* verify channel size */
+ if (expected_min_bytes > 0) {
+ if (ch->size < expected_min_bytes) {
+ dev_err(dev, "Channel mismatch on channel=%s(%pUL) field=size expected=0x%-8.8Lx actual=0x%-8.8Lx\n",
+ chname, expected_guid,
+ (unsigned long long)expected_min_bytes,
+ ch->size);
+ return 0;
+ }
+ }
+ /* verify channel version */
+ if (expected_version > 0) {
+ if (ch->version_id != expected_version) {
+ dev_err(dev, "Channel mismatch on channel=%s(%pUL) field=version expected=0x%-8.8lx actual=0x%-8.8x\n",
+ chname, expected_guid,
+ (unsigned long)expected_version,
+ ch->version_id);
+ return 0;
+ }
+ }
+ /* verify channel signature */
+ if (expected_signature > 0) {
+ if (ch->signature != expected_signature) {
+ dev_err(dev, "Channel mismatch on channel=%s(%pUL) field=signature expected=0x%-8.8Lx actual=0x%-8.8Lx\n",
+ chname, expected_guid, expected_signature,
+ ch->signature);
+ return 0;
+ }
+ }
+ return 1;
+}
+
+static int visorbus_uevent(struct device *xdev, struct kobj_uevent_env *env)
+{
+ struct visor_device *dev;
+ const guid_t *guid;
+
+ dev = to_visor_device(xdev);
+ guid = visorchannel_get_guid(dev->visorchannel);
+ return add_uevent_var(env, "MODALIAS=visorbus:%pUl", guid);
+}
+
+/*
+ * visorbus_match() - called automatically upon adding a visor_device
+ * (device_add), or adding a visor_driver
+ * (visorbus_register_visor_driver)
+ * @xdev: struct device for the device being matched
+ * @xdrv: struct device_driver for driver to match device against
+ *
+ * Return: 1 iff the provided driver can control the specified device
+ */
+static int visorbus_match(struct device *xdev, struct device_driver *xdrv)
+{
+ const guid_t *channel_type;
+ int i;
+ struct visor_device *dev;
+ struct visor_driver *drv;
+ struct visorchannel *chan;
+
+ dev = to_visor_device(xdev);
+ channel_type = visorchannel_get_guid(dev->visorchannel);
+ drv = to_visor_driver(xdrv);
+ chan = dev->visorchannel;
+ if (!drv->channel_types)
+ return 0;
+ for (i = 0; !guid_is_null(&drv->channel_types[i].guid); i++)
+ if (guid_equal(&drv->channel_types[i].guid, channel_type) &&
+ visor_check_channel(visorchannel_get_header(chan),
+ xdev,
+ &drv->channel_types[i].guid,
+ (char *)drv->channel_types[i].name,
+ drv->channel_types[i].min_bytes,
+ drv->channel_types[i].version,
+ VISOR_CHANNEL_SIGNATURE))
+ return i + 1;
+ return 0;
+}
+
+/*
+ * This describes the TYPE of bus.
+ * (Don't confuse this with an INSTANCE of the bus.)
+ */
+static struct bus_type visorbus_type = {
+ .name = "visorbus",
+ .match = visorbus_match,
+ .uevent = visorbus_uevent,
+ .dev_groups = visorbus_dev_groups,
+};
+
+struct visor_busdev {
+ u32 bus_no;
+ u32 dev_no;
+};
+
+static int match_visorbus_dev_by_id(struct device *dev, void *data)
+{
+ struct visor_device *vdev = to_visor_device(dev);
+ struct visor_busdev *id = data;
+
+ if (vdev->chipset_bus_no == id->bus_no &&
+ vdev->chipset_dev_no == id->dev_no)
+ return 1;
+ return 0;
+}
+
+struct visor_device *visorbus_get_device_by_id(u32 bus_no, u32 dev_no,
+ struct visor_device *from)
+{
+ struct device *dev;
+ struct device *dev_start = NULL;
+ struct visor_busdev id = {
+ .bus_no = bus_no,
+ .dev_no = dev_no
+ };
+
+ if (from)
+ dev_start = &from->device;
+ dev = bus_find_device(&visorbus_type, dev_start, (void *)&id,
+ match_visorbus_dev_by_id);
+ if (!dev)
+ return NULL;
+ return to_visor_device(dev);
+}
+
+/*
+ * visorbus_release_busdevice() - called when device_unregister() is called for
+ * the bus device instance, after all other tasks
+ * involved with destroying the dev are complete
+ * @xdev: struct device for the bus being released
+ */
+static void visorbus_release_busdevice(struct device *xdev)
+{
+ struct visor_device *dev = dev_get_drvdata(xdev);
+
+ debugfs_remove(dev->debugfs_bus_info);
+ debugfs_remove_recursive(dev->debugfs_dir);
+ visorchannel_destroy(dev->visorchannel);
+ kfree(dev);
+}
+
+/*
+ * visorbus_release_device() - called when device_unregister() is called for
+ * each child device instance
+ * @xdev: struct device for the visor device being released
+ */
+static void visorbus_release_device(struct device *xdev)
+{
+ struct visor_device *dev = to_visor_device(xdev);
+
+ visorchannel_destroy(dev->visorchannel);
+ kfree(dev);
+}
+
+/*
+ * BUS specific channel attributes to appear under
+ * /sys/bus/visorbus<x>/dev<y>/channel
+ */
+
+static ssize_t physaddr_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct visor_device *vdev = to_visor_device(dev);
+
+ return sprintf(buf, "0x%llx\n",
+ visorchannel_get_physaddr(vdev->visorchannel));
+}
+static DEVICE_ATTR_RO(physaddr);
+
+static ssize_t nbytes_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct visor_device *vdev = to_visor_device(dev);
+
+ return sprintf(buf, "0x%lx\n",
+ visorchannel_get_nbytes(vdev->visorchannel));
+}
+static DEVICE_ATTR_RO(nbytes);
+
+static ssize_t clientpartition_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct visor_device *vdev = to_visor_device(dev);
+
+ return sprintf(buf, "0x%llx\n",
+ visorchannel_get_clientpartition(vdev->visorchannel));
+}
+static DEVICE_ATTR_RO(clientpartition);
+
+static ssize_t typeguid_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct visor_device *vdev = to_visor_device(dev);
+ char typeid[LINESIZE];
+
+ return sprintf(buf, "%s\n",
+ visorchannel_id(vdev->visorchannel, typeid));
+}
+static DEVICE_ATTR_RO(typeguid);
+
+static ssize_t zoneguid_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct visor_device *vdev = to_visor_device(dev);
+ char zoneid[LINESIZE];
+
+ return sprintf(buf, "%s\n",
+ visorchannel_zoneid(vdev->visorchannel, zoneid));
+}
+static DEVICE_ATTR_RO(zoneguid);
+
+static ssize_t typename_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ int i = 0;
+ struct bus_type *xbus = dev->bus;
+ struct device_driver *xdrv = dev->driver;
+ struct visor_driver *drv = NULL;
+
+ if (!xdrv)
+ return 0;
+ i = xbus->match(dev, xdrv);
+ if (!i)
+ return 0;
+ drv = to_visor_driver(xdrv);
+ return sprintf(buf, "%s\n", drv->channel_types[i - 1].name);
+}
+static DEVICE_ATTR_RO(typename);
+
+static struct attribute *channel_attrs[] = {
+ &dev_attr_physaddr.attr,
+ &dev_attr_nbytes.attr,
+ &dev_attr_clientpartition.attr,
+ &dev_attr_typeguid.attr,
+ &dev_attr_zoneguid.attr,
+ &dev_attr_typename.attr,
+ NULL
+};
+
+ATTRIBUTE_GROUPS(channel);
+
+/*
+ * BUS instance attributes
+ *
+ * define & implement display of bus attributes under
+ * /sys/bus/visorbus/devices/visorbus<n>.
+ */
+static ssize_t partition_handle_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct visor_device *vdev = to_visor_device(dev);
+ u64 handle = visorchannel_get_clientpartition(vdev->visorchannel);
+
+ return sprintf(buf, "0x%llx\n", handle);
+}
+static DEVICE_ATTR_RO(partition_handle);
+
+static ssize_t partition_guid_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct visor_device *vdev = to_visor_device(dev);
+
+ return sprintf(buf, "{%pUb}\n", &vdev->partition_guid);
+}
+static DEVICE_ATTR_RO(partition_guid);
+
+static ssize_t partition_name_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct visor_device *vdev = to_visor_device(dev);
+
+ return sprintf(buf, "%s\n", vdev->name);
+}
+static DEVICE_ATTR_RO(partition_name);
+
+static ssize_t channel_addr_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct visor_device *vdev = to_visor_device(dev);
+ u64 addr = visorchannel_get_physaddr(vdev->visorchannel);
+
+ return sprintf(buf, "0x%llx\n", addr);
+}
+static DEVICE_ATTR_RO(channel_addr);
+
+static ssize_t channel_bytes_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct visor_device *vdev = to_visor_device(dev);
+ u64 nbytes = visorchannel_get_nbytes(vdev->visorchannel);
+
+ return sprintf(buf, "0x%llx\n", nbytes);
+}
+static DEVICE_ATTR_RO(channel_bytes);
+
+static ssize_t channel_id_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct visor_device *vdev = to_visor_device(dev);
+ int len = 0;
+
+ visorchannel_id(vdev->visorchannel, buf);
+ len = strlen(buf);
+ buf[len++] = '\n';
+ return len;
+}
+static DEVICE_ATTR_RO(channel_id);
+
+static struct attribute *visorbus_attrs[] = {
+ &dev_attr_partition_handle.attr,
+ &dev_attr_partition_guid.attr,
+ &dev_attr_partition_name.attr,
+ &dev_attr_channel_addr.attr,
+ &dev_attr_channel_bytes.attr,
+ &dev_attr_channel_id.attr,
+ NULL
+};
+
+ATTRIBUTE_GROUPS(visorbus);
+
+/*
+ * BUS debugfs entries
+ *
+ * define & implement display of debugfs attributes under
+ * /sys/kernel/debug/visorbus/visorbus<n>.
+ */
+
+/*
+ * vbuschannel_print_devinfo() - format a struct visor_vbus_deviceinfo
+ * and write it to a seq_file
+ * @devinfo: the struct visor_vbus_deviceinfo to format
+ * @seq: seq_file to write to
+ * @devix: the device index to be included in the output data, or -1 if no
+ * device index is to be included
+ *
+ * Reads @devInfo, and writes it in human-readable notation to @seq.
+ */
+static void vbuschannel_print_devinfo(struct visor_vbus_deviceinfo *devinfo,
+ struct seq_file *seq, int devix)
+{
+ /* uninitialized vbus device entry */
+ if (!isprint(devinfo->devtype[0]))
+ return;
+ if (devix >= 0)
+ seq_printf(seq, "[%d]", devix);
+ else
+ /* vbus device entry is for bus or chipset */
+ seq_puts(seq, " ");
+ /*
+ * Note: because the s-Par back-end is free to scribble in this area,
+ * we never assume '\0'-termination.
+ */
+ seq_printf(seq, "%-*.*s ", (int)sizeof(devinfo->devtype),
+ (int)sizeof(devinfo->devtype), devinfo->devtype);
+ seq_printf(seq, "%-*.*s ", (int)sizeof(devinfo->drvname),
+ (int)sizeof(devinfo->drvname), devinfo->drvname);
+ seq_printf(seq, "%.*s\n", (int)sizeof(devinfo->infostrs),
+ devinfo->infostrs);
+}
+
+static int bus_info_debugfs_show(struct seq_file *seq, void *v)
+{
+ int i = 0;
+ unsigned long off;
+ struct visor_vbus_deviceinfo dev_info;
+ struct visor_device *vdev = seq->private;
+ struct visorchannel *channel = vdev->visorchannel;
+
+ if (!channel)
+ return 0;
+
+ seq_printf(seq,
+ "Client device/driver info for %s partition (vbus #%u):\n",
+ ((vdev->name) ? (char *)(vdev->name) : ""),
+ vdev->chipset_bus_no);
+ if (visorchannel_read(channel,
+ offsetof(struct visor_vbus_channel, chp_info),
+ &dev_info, sizeof(dev_info)) >= 0)
+ vbuschannel_print_devinfo(&dev_info, seq, -1);
+ if (visorchannel_read(channel,
+ offsetof(struct visor_vbus_channel, bus_info),
+ &dev_info, sizeof(dev_info)) >= 0)
+ vbuschannel_print_devinfo(&dev_info, seq, -1);
+
+ off = offsetof(struct visor_vbus_channel, dev_info);
+ while (off + sizeof(dev_info) <= visorchannel_get_nbytes(channel)) {
+ if (visorchannel_read(channel, off, &dev_info,
+ sizeof(dev_info)) >= 0)
+ vbuschannel_print_devinfo(&dev_info, seq, i);
+ off += sizeof(dev_info);
+ i++;
+ }
+ return 0;
+}
+
+static int bus_info_debugfs_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, bus_info_debugfs_show, inode->i_private);
+}
+
+static const struct file_operations bus_info_debugfs_fops = {
+ .owner = THIS_MODULE,
+ .open = bus_info_debugfs_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static void dev_periodic_work(struct timer_list *t)
+{
+ struct visor_device *dev = from_timer(dev, t, timer);
+ struct visor_driver *drv = to_visor_driver(dev->device.driver);
+
+ drv->channel_interrupt(dev);
+ mod_timer(&dev->timer, jiffies + POLLJIFFIES_NORMALCHANNEL);
+}
+
+static int dev_start_periodic_work(struct visor_device *dev)
+{
+ if (dev->being_removed || dev->timer_active)
+ return -EINVAL;
+
+ /* now up by at least 2 */
+ get_device(&dev->device);
+ dev->timer.expires = jiffies + POLLJIFFIES_NORMALCHANNEL;
+ add_timer(&dev->timer);
+ dev->timer_active = true;
+ return 0;
+}
+
+static void dev_stop_periodic_work(struct visor_device *dev)
+{
+ if (!dev->timer_active)
+ return;
+
+ del_timer_sync(&dev->timer);
+ dev->timer_active = false;
+ put_device(&dev->device);
+}
+
+/*
+ * visordriver_remove_device() - handle visor device going away
+ * @xdev: struct device for the visor device being removed
+ *
+ * This is called when device_unregister() is called for each child device
+ * instance, to notify the appropriate visorbus function driver that the device
+ * is going away, and to decrease the reference count of the device.
+ *
+ * Return: 0 iff successful
+ */
+static int visordriver_remove_device(struct device *xdev)
+{
+ struct visor_device *dev = to_visor_device(xdev);
+ struct visor_driver *drv = to_visor_driver(xdev->driver);
+
+ mutex_lock(&dev->visordriver_callback_lock);
+ dev->being_removed = true;
+ drv->remove(dev);
+ mutex_unlock(&dev->visordriver_callback_lock);
+ dev_stop_periodic_work(dev);
+ put_device(&dev->device);
+ return 0;
+}
+
+/*
+ * visorbus_unregister_visor_driver() - unregisters the provided driver
+ * @drv: the driver to unregister
+ *
+ * A visor function driver calls this function to unregister the driver,
+ * i.e., within its module_exit function.
+ */
+void visorbus_unregister_visor_driver(struct visor_driver *drv)
+{
+ driver_unregister(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(visorbus_unregister_visor_driver);
+
+/*
+ * visorbus_read_channel() - reads from the designated channel into
+ * the provided buffer
+ * @dev: the device whose channel is read from
+ * @offset: the offset into the channel at which reading starts
+ * @dest: the destination buffer that is written into from the channel
+ * @nbytes: the number of bytes to read from the channel
+ *
+ * If receiving a message, use the visorchannel_signalremove() function instead.
+ *
+ * Return: integer indicating success (zero) or failure (non-zero)
+ */
+int visorbus_read_channel(struct visor_device *dev, unsigned long offset,
+ void *dest, unsigned long nbytes)
+{
+ return visorchannel_read(dev->visorchannel, offset, dest, nbytes);
+}
+EXPORT_SYMBOL_GPL(visorbus_read_channel);
+
+/*
+ * visorbus_write_channel() - writes the provided buffer into the designated
+ * channel
+ * @dev: the device whose channel is written to
+ * @offset: the offset into the channel at which writing starts
+ * @src: the source buffer that is written into the channel
+ * @nbytes: the number of bytes to write into the channel
+ *
+ * If sending a message, use the visorchannel_signalinsert() function instead.
+ *
+ * Return: integer indicating success (zero) or failure (non-zero)
+ */
+int visorbus_write_channel(struct visor_device *dev, unsigned long offset,
+ void *src, unsigned long nbytes)
+{
+ return visorchannel_write(dev->visorchannel, offset, src, nbytes);
+}
+EXPORT_SYMBOL_GPL(visorbus_write_channel);
+
+/*
+ * visorbus_enable_channel_interrupts() - enables interrupts on the
+ * designated device
+ * @dev: the device on which to enable interrupts
+ *
+ * Currently we don't yet have a real interrupt, so for now we just call the
+ * interrupt function periodically via a timer.
+ */
+int visorbus_enable_channel_interrupts(struct visor_device *dev)
+{
+ struct visor_driver *drv = to_visor_driver(dev->device.driver);
+
+ if (!drv->channel_interrupt) {
+ dev_err(&dev->device, "%s no interrupt function!\n", __func__);
+ return -ENOENT;
+ }
+
+ return dev_start_periodic_work(dev);
+}
+EXPORT_SYMBOL_GPL(visorbus_enable_channel_interrupts);
+
+/*
+ * visorbus_disable_channel_interrupts() - disables interrupts on the
+ * designated device
+ * @dev: the device on which to disable interrupts
+ */
+void visorbus_disable_channel_interrupts(struct visor_device *dev)
+{
+ dev_stop_periodic_work(dev);
+}
+EXPORT_SYMBOL_GPL(visorbus_disable_channel_interrupts);
+
+/*
+ * create_visor_device() - create visor device as a result of receiving the
+ * controlvm device_create message for a new device
+ * @dev: a freshly-zeroed struct visor_device, containing only filled-in values
+ * for chipset_bus_no and chipset_dev_no, that will be initialized
+ *
+ * This is how everything starts from the device end.
+ * This function is called when a channel first appears via a ControlVM
+ * message. In response, this function allocates a visor_device to correspond
+ * to the new channel, and attempts to connect it the appropriate * driver. If
+ * the appropriate driver is found, the visor_driver.probe() function for that
+ * driver will be called, and will be passed the new * visor_device that we
+ * just created.
+ *
+ * It's ok if the appropriate driver is not yet loaded, because in that case
+ * the new device struct will just stick around in the bus' list of devices.
+ * When the appropriate driver calls visorbus_register_visor_driver(), the
+ * visor_driver.probe() for the new driver will be called with the new device.
+ *
+ * Return: 0 if successful, otherwise the negative value returned by
+ * device_add() indicating the reason for failure
+ */
+int create_visor_device(struct visor_device *dev)
+{
+ int err;
+ u32 chipset_bus_no = dev->chipset_bus_no;
+ u32 chipset_dev_no = dev->chipset_dev_no;
+
+ mutex_init(&dev->visordriver_callback_lock);
+ dev->device.bus = &visorbus_type;
+ dev->device.groups = channel_groups;
+ device_initialize(&dev->device);
+ dev->device.release = visorbus_release_device;
+ /* keep a reference just for us (now 2) */
+ get_device(&dev->device);
+ timer_setup(&dev->timer, dev_periodic_work, 0);
+ /*
+ * bus_id must be a unique name with respect to this bus TYPE (NOT bus
+ * instance). That's why we need to include the bus number within the
+ * name.
+ */
+ err = dev_set_name(&dev->device, "vbus%u:dev%u",
+ chipset_bus_no, chipset_dev_no);
+ if (err)
+ goto err_put;
+ /*
+ * device_add does this:
+ * bus_add_device(dev)
+ * ->device_attach(dev)
+ * ->for each driver drv registered on the bus that dev is on
+ * if (dev.drv) ** device already has a driver **
+ * ** not sure we could ever get here... **
+ * else
+ * if (bus.match(dev,drv)) [visorbus_match]
+ * dev.drv = drv
+ * if (!drv.probe(dev)) [visordriver_probe_device]
+ * dev.drv = NULL
+ *
+ * Note that device_add does NOT fail if no driver failed to claim the
+ * device. The device will be linked onto bus_type.klist_devices
+ * regardless (use bus_for_each_dev).
+ */
+ err = device_add(&dev->device);
+ if (err < 0)
+ goto err_put;
+ list_add_tail(&dev->list_all, &list_all_device_instances);
+ dev->state.created = 1;
+ visorbus_response(dev, err, CONTROLVM_DEVICE_CREATE);
+ /* success: reference kept via unmatched get_device() */
+ return 0;
+
+err_put:
+ put_device(&dev->device);
+ dev_err(&dev->device, "Creating visor device failed. %d\n", err);
+ return err;
+}
+
+void remove_visor_device(struct visor_device *dev)
+{
+ list_del(&dev->list_all);
+ put_device(&dev->device);
+ if (dev->pending_msg_hdr)
+ visorbus_response(dev, 0, CONTROLVM_DEVICE_DESTROY);
+ device_unregister(&dev->device);
+}
+
+static int get_vbus_header_info(struct visorchannel *chan,
+ struct device *dev,
+ struct visor_vbus_headerinfo *hdr_info)
+{
+ int err;
+
+ if (!visor_check_channel(visorchannel_get_header(chan),
+ dev,
+ &visor_vbus_channel_guid,
+ "vbus",
+ sizeof(struct visor_vbus_channel),
+ VISOR_VBUS_CHANNEL_VERSIONID,
+ VISOR_CHANNEL_SIGNATURE))
+ return -EINVAL;
+
+ err = visorchannel_read(chan, sizeof(struct channel_header), hdr_info,
+ sizeof(*hdr_info));
+ if (err < 0)
+ return err;
+ if (hdr_info->struct_bytes < sizeof(struct visor_vbus_headerinfo))
+ return -EINVAL;
+ if (hdr_info->device_info_struct_bytes <
+ sizeof(struct visor_vbus_deviceinfo))
+ return -EINVAL;
+ return 0;
+}
+
+/*
+ * write_vbus_chp_info() - write the contents of <info> to the struct
+ * visor_vbus_channel.chp_info
+ * @chan: indentifies the s-Par channel that will be updated
+ * @hdr_info: used to find appropriate channel offset to write data
+ * @info: contains the information to write
+ *
+ * Writes chipset info into the channel memory to be used for diagnostic
+ * purposes.
+ *
+ * Returns no value since this is debug information and not needed for
+ * device functionality.
+ */
+static void write_vbus_chp_info(struct visorchannel *chan,
+ struct visor_vbus_headerinfo *hdr_info,
+ struct visor_vbus_deviceinfo *info)
+{
+ int off;
+
+ if (hdr_info->chp_info_offset == 0)
+ return;
+
+ off = sizeof(struct channel_header) + hdr_info->chp_info_offset;
+ visorchannel_write(chan, off, info, sizeof(*info));
+}
+
+/*
+ * write_vbus_bus_info() - write the contents of <info> to the struct
+ * visor_vbus_channel.bus_info
+ * @chan: indentifies the s-Par channel that will be updated
+ * @hdr_info: used to find appropriate channel offset to write data
+ * @info: contains the information to write
+ *
+ * Writes bus info into the channel memory to be used for diagnostic
+ * purposes.
+ *
+ * Returns no value since this is debug information and not needed for
+ * device functionality.
+ */
+static void write_vbus_bus_info(struct visorchannel *chan,
+ struct visor_vbus_headerinfo *hdr_info,
+ struct visor_vbus_deviceinfo *info)
+{
+ int off;
+
+ if (hdr_info->bus_info_offset == 0)
+ return;
+
+ off = sizeof(struct channel_header) + hdr_info->bus_info_offset;
+ visorchannel_write(chan, off, info, sizeof(*info));
+}
+
+/*
+ * write_vbus_dev_info() - write the contents of <info> to the struct
+ * visor_vbus_channel.dev_info[<devix>]
+ * @chan: indentifies the s-Par channel that will be updated
+ * @hdr_info: used to find appropriate channel offset to write data
+ * @info: contains the information to write
+ * @devix: the relative device number (0..n-1) of the device on the bus
+ *
+ * Writes device info into the channel memory to be used for diagnostic
+ * purposes.
+ *
+ * Returns no value since this is debug information and not needed for
+ * device functionality.
+ */
+static void write_vbus_dev_info(struct visorchannel *chan,
+ struct visor_vbus_headerinfo *hdr_info,
+ struct visor_vbus_deviceinfo *info,
+ unsigned int devix)
+{
+ int off;
+
+ if (hdr_info->dev_info_offset == 0)
+ return;
+ off = (sizeof(struct channel_header) + hdr_info->dev_info_offset) +
+ (hdr_info->device_info_struct_bytes * devix);
+ visorchannel_write(chan, off, info, sizeof(*info));
+}
+
+static void bus_device_info_init(
+ struct visor_vbus_deviceinfo *bus_device_info_ptr,
+ const char *dev_type, const char *drv_name)
+{
+ memset(bus_device_info_ptr, 0, sizeof(struct visor_vbus_deviceinfo));
+ snprintf(bus_device_info_ptr->devtype,
+ sizeof(bus_device_info_ptr->devtype),
+ "%s", (dev_type) ? dev_type : "unknownType");
+ snprintf(bus_device_info_ptr->drvname,
+ sizeof(bus_device_info_ptr->drvname),
+ "%s", (drv_name) ? drv_name : "unknownDriver");
+ snprintf(bus_device_info_ptr->infostrs,
+ sizeof(bus_device_info_ptr->infostrs), "kernel ver. %s",
+ utsname()->release);
+}
+
+/*
+ * publish_vbus_dev_info() - for a child device just created on a client bus,
+ * fill in information about the driver that is
+ * controlling this device into the appropriate slot
+ * within the vbus channel of the bus instance
+ * @visordev: struct visor_device for the desired device
+ */
+static void publish_vbus_dev_info(struct visor_device *visordev)
+{
+ int i;
+ struct visor_device *bdev;
+ struct visor_driver *visordrv;
+ u32 bus_no = visordev->chipset_bus_no;
+ u32 dev_no = visordev->chipset_dev_no;
+ struct visor_vbus_deviceinfo dev_info;
+ const char *chan_type_name = NULL;
+ struct visor_vbus_headerinfo *hdr_info;
+
+ if (!visordev->device.driver)
+ return;
+ bdev = visorbus_get_device_by_id(bus_no, BUS_ROOT_DEVICE, NULL);
+ if (!bdev)
+ return;
+ hdr_info = (struct visor_vbus_headerinfo *)bdev->vbus_hdr_info;
+ if (!hdr_info)
+ return;
+ visordrv = to_visor_driver(visordev->device.driver);
+
+ /*
+ * Within the list of device types (by GUID) that the driver
+ * says it supports, find out which one of those types matches
+ * the type of this device, so that we can include the device
+ * type name
+ */
+ for (i = 0; visordrv->channel_types[i].name; i++) {
+ if (guid_equal(&visordrv->channel_types[i].guid,
+ &visordev->channel_type_guid)) {
+ chan_type_name = visordrv->channel_types[i].name;
+ break;
+ }
+ }
+ bus_device_info_init(&dev_info, chan_type_name, visordrv->name);
+ write_vbus_dev_info(bdev->visorchannel, hdr_info, &dev_info, dev_no);
+ write_vbus_chp_info(bdev->visorchannel, hdr_info, &chipset_driverinfo);
+ write_vbus_bus_info(bdev->visorchannel, hdr_info,
+ &clientbus_driverinfo);
+}
+
+/*
+ * visordriver_probe_device() - handle new visor device coming online
+ * @xdev: struct device for the visor device being probed
+ *
+ * This is called automatically upon adding a visor_device (device_add), or
+ * adding a visor_driver (visorbus_register_visor_driver), but only after
+ * visorbus_match() has returned 1 to indicate a successful match between
+ * driver and device.
+ *
+ * If successful, a reference to the device will be held onto via get_device().
+ *
+ * Return: 0 if successful, meaning the function driver's probe() function
+ * was successful with this device, otherwise a negative errno
+ * value indicating failure reason
+ */
+static int visordriver_probe_device(struct device *xdev)
+{
+ int err;
+ struct visor_driver *drv = to_visor_driver(xdev->driver);
+ struct visor_device *dev = to_visor_device(xdev);
+
+ mutex_lock(&dev->visordriver_callback_lock);
+ dev->being_removed = false;
+ err = drv->probe(dev);
+ if (err) {
+ mutex_unlock(&dev->visordriver_callback_lock);
+ return err;
+ }
+ /* success: reference kept via unmatched get_device() */
+ get_device(&dev->device);
+ publish_vbus_dev_info(dev);
+ mutex_unlock(&dev->visordriver_callback_lock);
+ return 0;
+}
+
+/*
+ * visorbus_register_visor_driver() - registers the provided visor driver for
+ * handling one or more visor device
+ * types (channel_types)
+ * @drv: the driver to register
+ *
+ * A visor function driver calls this function to register the driver. The
+ * caller MUST fill in the following fields within the #drv structure:
+ * name, version, owner, channel_types, probe, remove
+ *
+ * Here's how the whole Linux bus / driver / device model works.
+ *
+ * At system start-up, the visorbus kernel module is loaded, which registers
+ * visorbus_type as a bus type, using bus_register().
+ *
+ * All kernel modules that support particular device types on a
+ * visorbus bus are loaded. Each of these kernel modules calls
+ * visorbus_register_visor_driver() in their init functions, passing a
+ * visor_driver struct. visorbus_register_visor_driver() in turn calls
+ * register_driver(&visor_driver.driver). This .driver member is
+ * initialized with generic methods (like probe), whose sole responsibility
+ * is to act as a broker for the real methods, which are within the
+ * visor_driver struct. (This is the way the subclass behavior is
+ * implemented, since visor_driver is essentially a subclass of the
+ * generic driver.) Whenever a driver_register() happens, core bus code in
+ * the kernel does (see device_attach() in drivers/base/dd.c):
+ *
+ * for each dev associated with the bus (the bus that driver is on) that
+ * does not yet have a driver
+ * if bus.match(dev,newdriver) == yes_matched ** .match specified
+ * ** during bus_register().
+ * newdriver.probe(dev) ** for visor drivers, this will call
+ * ** the generic driver.probe implemented in visorbus.c,
+ * ** which in turn calls the probe specified within the
+ * ** struct visor_driver (which was specified by the
+ * ** actual device driver as part of
+ * ** visorbus_register_visor_driver()).
+ *
+ * The above dance also happens when a new device appears.
+ * So the question is, how are devices created within the system?
+ * Basically, just call device_add(dev). See pci_bus_add_devices().
+ * pci_scan_device() shows an example of how to build a device struct. It
+ * returns the newly-created struct to pci_scan_single_device(), who adds it
+ * to the list of devices at PCIBUS.devices. That list of devices is what
+ * is traversed by pci_bus_add_devices().
+ *
+ * Return: integer indicating success (zero) or failure (non-zero)
+ */
+int visorbus_register_visor_driver(struct visor_driver *drv)
+{
+ /* can't register on a nonexistent bus */
+ if (!initialized)
+ return -ENODEV;
+ if (!drv->probe)
+ return -EINVAL;
+ if (!drv->remove)
+ return -EINVAL;
+ if (!drv->pause)
+ return -EINVAL;
+ if (!drv->resume)
+ return -EINVAL;
+
+ drv->driver.name = drv->name;
+ drv->driver.bus = &visorbus_type;
+ drv->driver.probe = visordriver_probe_device;
+ drv->driver.remove = visordriver_remove_device;
+ drv->driver.owner = drv->owner;
+ /*
+ * driver_register does this:
+ * bus_add_driver(drv)
+ * ->if (drv.bus) ** (bus_type) **
+ * driver_attach(drv)
+ * for each dev with bus type of drv.bus
+ * if (!dev.drv) ** no driver assigned yet **
+ * if (bus.match(dev,drv)) [visorbus_match]
+ * dev.drv = drv
+ * if (!drv.probe(dev)) [visordriver_probe_device]
+ * dev.drv = NULL
+ */
+ return driver_register(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(visorbus_register_visor_driver);
+
+/*
+ * visorbus_create_instance() - create a device instance for the visorbus itself
+ * @dev: struct visor_device indicating the bus instance
+ *
+ * Return: 0 for success, otherwise negative errno value indicating reason for
+ * failure
+ */
+int visorbus_create_instance(struct visor_device *dev)
+{
+ int id = dev->chipset_bus_no;
+ int err;
+ struct visor_vbus_headerinfo *hdr_info;
+
+ hdr_info = kzalloc(sizeof(*hdr_info), GFP_KERNEL);
+ if (!hdr_info)
+ return -ENOMEM;
+ dev_set_name(&dev->device, "visorbus%d", id);
+ dev->device.bus = &visorbus_type;
+ dev->device.groups = visorbus_groups;
+ dev->device.release = visorbus_release_busdevice;
+ dev->debugfs_dir = debugfs_create_dir(dev_name(&dev->device),
+ visorbus_debugfs_dir);
+ dev->debugfs_bus_info = debugfs_create_file("client_bus_info", 0440,
+ dev->debugfs_dir, dev,
+ &bus_info_debugfs_fops);
+ dev_set_drvdata(&dev->device, dev);
+ err = get_vbus_header_info(dev->visorchannel, &dev->device, hdr_info);
+ if (err < 0)
+ goto err_debugfs_dir;
+ err = device_register(&dev->device);
+ if (err < 0)
+ goto err_debugfs_dir;
+ list_add_tail(&dev->list_all, &list_all_bus_instances);
+ dev->state.created = 1;
+ dev->vbus_hdr_info = (void *)hdr_info;
+ write_vbus_chp_info(dev->visorchannel, hdr_info, &chipset_driverinfo);
+ write_vbus_bus_info(dev->visorchannel, hdr_info, &clientbus_driverinfo);
+ visorbus_response(dev, err, CONTROLVM_BUS_CREATE);
+ return 0;
+
+err_debugfs_dir:
+ debugfs_remove_recursive(dev->debugfs_dir);
+ kfree(hdr_info);
+ dev_err(&dev->device, "%s failed: %d\n", __func__, err);
+ return err;
+}
+
+/*
+ * visorbus_remove_instance() - remove a device instance for the visorbus itself
+ * @dev: struct visor_device indentifying the bus to remove
+ */
+void visorbus_remove_instance(struct visor_device *dev)
+{
+ /*
+ * Note that this will result in the release method for
+ * dev->dev being called, which will call
+ * visorbus_release_busdevice(). This has something to do with
+ * the put_device() done in device_unregister(), but I have never
+ * successfully been able to trace thru the code to see where/how
+ * release() gets called. But I know it does.
+ */
+ kfree(dev->vbus_hdr_info);
+ list_del(&dev->list_all);
+ if (dev->pending_msg_hdr)
+ visorbus_response(dev, 0, CONTROLVM_BUS_DESTROY);
+ device_unregister(&dev->device);
+}
+
+/*
+ * remove_all_visor_devices() - remove all child visorbus device instances
+ */
+static void remove_all_visor_devices(void)
+{
+ struct list_head *listentry, *listtmp;
+
+ list_for_each_safe(listentry, listtmp, &list_all_device_instances) {
+ struct visor_device *dev;
+
+ dev = list_entry(listentry, struct visor_device, list_all);
+ remove_visor_device(dev);
+ }
+}
+
+/*
+ * pause_state_change_complete() - the callback function to be called by a
+ * visorbus function driver when a
+ * pending "pause device" operation has
+ * completed
+ * @dev: struct visor_device identifying the paused device
+ * @status: 0 iff the pause state change completed successfully, otherwise
+ * a negative errno value indicating the reason for failure
+ */
+static void pause_state_change_complete(struct visor_device *dev, int status)
+{
+ if (!dev->pausing)
+ return;
+
+ dev->pausing = false;
+ visorbus_device_changestate_response(dev, status,
+ segment_state_standby);
+}
+
+/*
+ * resume_state_change_complete() - the callback function to be called by a
+ * visorbus function driver when a
+ * pending "resume device" operation has
+ * completed
+ * @dev: struct visor_device identifying the resumed device
+ * @status: 0 iff the resume state change completed successfully, otherwise
+ * a negative errno value indicating the reason for failure
+ */
+static void resume_state_change_complete(struct visor_device *dev, int status)
+{
+ if (!dev->resuming)
+ return;
+
+ dev->resuming = false;
+ /*
+ * Notify the chipset driver that the resume is complete,
+ * which will presumably want to send some sort of response to
+ * the initiator.
+ */
+ visorbus_device_changestate_response(dev, status,
+ segment_state_running);
+}
+
+/*
+ * visorchipset_initiate_device_pause_resume() - start a pause or resume
+ * operation for a visor device
+ * @dev: struct visor_device identifying the device being paused or resumed
+ * @is_pause: true to indicate pause operation, false to indicate resume
+ *
+ * Tell the subordinate function driver for a specific device to pause
+ * or resume that device. Success/failure result is returned asynchronously
+ * via a callback function; see pause_state_change_complete() and
+ * resume_state_change_complete().
+ */
+static int visorchipset_initiate_device_pause_resume(struct visor_device *dev,
+ bool is_pause)
+{
+ int err;
+ struct visor_driver *drv;
+
+ /* If no driver associated with the device nothing to pause/resume */
+ if (!dev->device.driver)
+ return 0;
+ if (dev->pausing || dev->resuming)
+ return -EBUSY;
+
+ drv = to_visor_driver(dev->device.driver);
+ if (is_pause) {
+ dev->pausing = true;
+ err = drv->pause(dev, pause_state_change_complete);
+ } else {
+ /*
+ * The vbus_dev_info structure in the channel was been cleared,
+ * make sure it is valid.
+ */
+ publish_vbus_dev_info(dev);
+ dev->resuming = true;
+ err = drv->resume(dev, resume_state_change_complete);
+ }
+ return err;
+}
+
+/*
+ * visorchipset_device_pause() - start a pause operation for a visor device
+ * @dev_info: struct visor_device identifying the device being paused
+ *
+ * Tell the subordinate function driver for a specific device to pause
+ * that device. Success/failure result is returned asynchronously
+ * via a callback function; see pause_state_change_complete().
+ */
+int visorchipset_device_pause(struct visor_device *dev_info)
+{
+ int err;
+
+ err = visorchipset_initiate_device_pause_resume(dev_info, true);
+ if (err < 0) {
+ dev_info->pausing = false;
+ return err;
+ }
+ return 0;
+}
+
+/*
+ * visorchipset_device_resume() - start a resume operation for a visor device
+ * @dev_info: struct visor_device identifying the device being resumed
+ *
+ * Tell the subordinate function driver for a specific device to resume
+ * that device. Success/failure result is returned asynchronously
+ * via a callback function; see resume_state_change_complete().
+ */
+int visorchipset_device_resume(struct visor_device *dev_info)
+{
+ int err;
+
+ err = visorchipset_initiate_device_pause_resume(dev_info, false);
+ if (err < 0) {
+ dev_info->resuming = false;
+ return err;
+ }
+ return 0;
+}
+
+int visorbus_init(void)
+{
+ int err;
+
+ visorbus_debugfs_dir = debugfs_create_dir("visorbus", NULL);
+ bus_device_info_init(&clientbus_driverinfo, "clientbus", "visorbus");
+ err = bus_register(&visorbus_type);
+ if (err < 0)
+ return err;
+ initialized = true;
+ bus_device_info_init(&chipset_driverinfo, "chipset", "visorchipset");
+ return 0;
+}
+
+void visorbus_exit(void)
+{
+ struct list_head *listentry, *listtmp;
+
+ remove_all_visor_devices();
+ list_for_each_safe(listentry, listtmp, &list_all_bus_instances) {
+ struct visor_device *dev;
+
+ dev = list_entry(listentry, struct visor_device, list_all);
+ visorbus_remove_instance(dev);
+ }
+ bus_unregister(&visorbus_type);
+ initialized = false;
+ debugfs_remove_recursive(visorbus_debugfs_dir);
+}
projects / linux-2.6-microblaze.git / blobdiff