| // 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, const void *data) |
| { |
| struct visor_device *vdev = to_visor_device(dev); |
| const 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); |
| } |