diff options
Diffstat (limited to 'drivers/visorbus/visorbus_main.c')
| -rw-r--r-- | drivers/visorbus/visorbus_main.c | 1234 |
1 files changed, 1234 insertions, 0 deletions
diff --git a/drivers/visorbus/visorbus_main.c b/drivers/visorbus/visorbus_main.c new file mode 100644 index 000000000000..0b2434cc4ecd --- /dev/null +++ b/drivers/visorbus/visorbus_main.c @@ -0,0 +1,1234 @@ +// 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); +} |