// 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);
}
