// SPDX-License-Identifier: GPL-2.0 /* * Copyright � 2010 - 2015 UNISYS CORPORATION * All rights reserved. */ #include #include #include #include #include #include #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 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/dev/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. */ 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. */ /* * 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 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 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 to the struct * visor_vbus_channel.dev_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 * @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); }