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*
* Copyright � 2010 - 2015 UNISYS CORPORATION
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for more
* details.
*/
#include <linux/debugfs.h>
#include <linux/uuid.h>
#include "visorbus.h"
#include "visorbus_private.h"
#include "vmcallinterface.h"
#define MYDRVNAME "visorbus"
/* module parameters */
static int visorbus_forcematch;
static int visorbus_forcenomatch;
/* Display string that is guaranteed to be no longer the 99 characters*/
#define LINESIZE 99
#define CURRENT_FILE_PC VISOR_BUS_PC_visorbus_main_c
#define POLLJIFFIES_NORMALCHANNEL 10
static int busreg_rc = -ENODEV; /* stores the result from bus registration */
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;
uuid_le guid;
vdev = to_visor_device(dev);
guid = visorchannel_get_uuid(vdev->visorchannel);
return snprintf(buf, PAGE_SIZE, "visorbus:%pUl\n", &guid);
}
static DEVICE_ATTR_RO(modalias);
static struct attribute *visorbus_dev_attrs[] = {
&dev_attr_modalias.attr,
NULL,
};
/* sysfs example for bridge-only sysfs files using device_type's */
static const struct attribute_group visorbus_dev_group = {
.attrs = visorbus_dev_attrs,
};
static const struct attribute_group *visorbus_dev_groups[] = {
&visorbus_dev_group,
NULL,
};
/* filled in with info about parent chipset driver when we register with it */
static struct ultra_vbus_deviceinfo chipset_driverinfo;
/* filled in with info about this driver, wrt it servicing client busses */
static struct ultra_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);
static int
visorbus_uevent(struct device *xdev, struct kobj_uevent_env *env)
{
struct visor_device *dev;
uuid_le guid;
dev = to_visor_device(xdev);
guid = visorchannel_get_uuid(dev->visorchannel);
if (add_uevent_var(env, "MODALIAS=visorbus:%pUl", &guid))
return -ENOMEM;
return 0;
}
/**
* 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)
{
uuid_le channel_type;
int i;
struct visor_device *dev;
struct visor_driver *drv;
dev = to_visor_device(xdev);
drv = to_visor_driver(xdrv);
channel_type = visorchannel_get_uuid(dev->visorchannel);
if (visorbus_forcematch)
return 1;
if (visorbus_forcenomatch)
return 0;
if (!drv->channel_types)
return 0;
for (i = 0;
(uuid_le_cmp(drv->channel_types[i].guid, NULL_UUID_LE) != 0) ||
(drv->channel_types[i].name);
i++)
if (uuid_le_cmp(drv->channel_types[i].guid,
channel_type) == 0)
return i + 1;
return 0;
}
/*
* This describes the TYPE of bus.
* (Don't confuse this with an INSTANCE of the bus.)
*/
struct bus_type visorbus_type = {
.name = "visorbus",
.match = visorbus_match,
.uevent = visorbus_uevent,
.dev_groups = visorbus_dev_groups,
};
/**
* visorbus_releae_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_client_bus_info);
debugfs_remove_recursive(dev->debugfs_dir);
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);
if (dev->visorchannel) {
visorchannel_destroy(dev->visorchannel);
dev->visorchannel = NULL;
}
kfree(dev);
}
/*
* begin implementation of 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);
if (!vdev->visorchannel)
return 0;
return snprintf(buf, PAGE_SIZE, "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);
if (!vdev->visorchannel)
return 0;
return snprintf(buf, PAGE_SIZE, "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);
if (!vdev->visorchannel)
return 0;
return snprintf(buf, PAGE_SIZE, "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];
if (!vdev->visorchannel)
return 0;
return snprintf(buf, PAGE_SIZE, "%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];
if (!vdev->visorchannel)
return 0;
return snprintf(buf, PAGE_SIZE, "%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)
{
struct visor_device *vdev = to_visor_device(dev);
int i = 0;
struct bus_type *xbus = dev->bus;
struct device_driver *xdrv = dev->driver;
struct visor_driver *drv = NULL;
if (!vdev->visorchannel || !xbus || !xdrv)
return 0;
i = xbus->match(dev, xdrv);
if (!i)
return 0;
drv = to_visor_driver(xdrv);
return snprintf(buf, PAGE_SIZE, "%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
};
static struct attribute_group channel_attr_grp = {
.name = "channel",
.attrs = channel_attrs,
};
static const struct attribute_group *visorbus_channel_groups[] = {
&channel_attr_grp,
NULL
};
/* end implementation of specific channel attributes */
/*
* 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 snprintf(buf, PAGE_SIZE, "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 snprintf(buf, PAGE_SIZE, "{%pUb}\n", &vdev->partition_uuid);
}
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 snprintf(buf, PAGE_SIZE, "%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 snprintf(buf, PAGE_SIZE, "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 snprintf(buf, PAGE_SIZE, "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;
if (vdev->visorchannel) {
visorchannel_id(vdev->visorchannel, buf);
len = strlen(buf);
buf[len++] = '\n';
}
return len;
}
static DEVICE_ATTR_RO(channel_id);
static struct attribute *dev_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
};
static struct attribute_group dev_attr_grp = {
.attrs = dev_attrs,
};
static const struct attribute_group *visorbus_groups[] = {
&dev_attr_grp,
NULL
};
/*
* BUS debugfs entries
*
* define & implement display of debugfs attributes under
* /sys/kernel/debug/visorbus/visorbus<n>.
*/
static int client_bus_info_debugfs_show(struct seq_file *seq, void *v)
{
struct visor_device *vdev = seq->private;
struct visorchannel *channel = vdev->visorchannel;
int i;
unsigned long off;
struct ultra_vbus_deviceinfo dev_info;
if (!channel)
return 0;
seq_printf(seq,
"Client device / client driver info for %s partition (vbus #%u):\n",
((vdev->name) ? (char *)(vdev->name) : ""),
vdev->chipset_bus_no);
if (visorchannel_read(channel,
offsetof(struct spar_vbus_channel_protocol,
chp_info),
&dev_info, sizeof(dev_info)) >= 0)
vbuschannel_print_devinfo(&dev_info, seq, -1);
if (visorchannel_read(channel,
offsetof(struct spar_vbus_channel_protocol,
bus_info),
&dev_info, sizeof(dev_info)) >= 0)
vbuschannel_print_devinfo(&dev_info, seq, -1);
off = offsetof(struct spar_vbus_channel_protocol, dev_info);
i = 0;
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 client_bus_info_debugfs_open(struct inode *inode, struct file *file)
{
return single_open(file, client_bus_info_debugfs_show,
inode->i_private);
}
static const struct file_operations client_bus_info_debugfs_fops = {
.owner = THIS_MODULE,
.open = client_bus_info_debugfs_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static void
dev_periodic_work(unsigned long __opaque)
{
struct visor_device *dev = (struct visor_device *)__opaque;
struct visor_driver *drv = to_visor_driver(dev->device.driver);
if (drv->channel_interrupt)
drv->channel_interrupt(dev);
mod_timer(&dev->timer, jiffies + POLLJIFFIES_NORMALCHANNEL);
}
static void
dev_start_periodic_work(struct visor_device *dev)
{
if (dev->being_removed || dev->timer_active)
return;
/* now up by at least 2 */
get_device(&dev->device);
dev->timer.expires = jiffies + POLLJIFFIES_NORMALCHANNEL;
add_timer(&dev->timer);
dev->timer_active = true;
}
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;
struct visor_driver *drv;
dev = to_visor_device(xdev);
drv = to_visor_driver(xdev->driver);
mutex_lock(&dev->visordriver_callback_lock);
dev->being_removed = true;
if (drv->remove)
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.
*/
void
visorbus_enable_channel_interrupts(struct visor_device *dev)
{
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
*/
static 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;
POSTCODE_LINUX(DEVICE_CREATE_ENTRY_PC, chipset_dev_no, chipset_bus_no,
DIAG_SEVERITY_PRINT);
mutex_init(&dev->visordriver_callback_lock);
dev->device.bus = &visorbus_type;
dev->device.groups = visorbus_channel_groups;
device_initialize(&dev->device);
dev->device.release = visorbus_release_device;
/* keep a reference just for us (now 2) */
get_device(&dev->device);
init_timer(&dev->timer);
dev->timer.data = (unsigned long)(dev);
dev->timer.function = dev_periodic_work;
/*
* 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.
*/
dev_set_name(&dev->device, "vbus%u:dev%u",
chipset_bus_no, chipset_dev_no);
/*
* 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) {
POSTCODE_LINUX(DEVICE_ADD_PC, 0, chipset_bus_no,
DIAG_SEVERITY_ERR);
goto err_put;
}
list_add_tail(&dev->list_all, &list_all_device_instances);
return 0; /* success: reference kept via unmatched get_device() */
err_put:
put_device(&dev->device);
return err;
}
static void
remove_visor_device(struct visor_device *dev)
{
list_del(&dev->list_all);
put_device(&dev->device);
device_unregister(&dev->device);
}
static int
get_vbus_header_info(struct visorchannel *chan,
struct spar_vbus_headerinfo *hdr_info)
{
if (!SPAR_VBUS_CHANNEL_OK_CLIENT(visorchannel_get_header(chan)))
return -EINVAL;
if (visorchannel_read(chan, sizeof(struct channel_header), hdr_info,
sizeof(*hdr_info)) < 0) {
return -EIO;
}
if (hdr_info->struct_bytes < sizeof(struct spar_vbus_headerinfo))
return -EINVAL;
if (hdr_info->device_info_struct_bytes <
sizeof(struct ultra_vbus_deviceinfo)) {
return -EINVAL;
}
return 0;
}
/**
* write_vbus_chp_info() - write the contents of <info> to the struct
* spar_vbus_channel_protocol.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 spar_vbus_headerinfo *hdr_info,
struct ultra_vbus_deviceinfo *info)
{
int off = sizeof(struct channel_header) + hdr_info->chp_info_offset;
if (hdr_info->chp_info_offset == 0)
return;
visorchannel_write(chan, off, info, sizeof(*info));
}
/**
* write_vbus_bus_info() - write the contents of <info> to the struct
* spar_vbus_channel_protocol.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 spar_vbus_headerinfo *hdr_info,
struct ultra_vbus_deviceinfo *info)
{
int off = sizeof(struct channel_header) + hdr_info->bus_info_offset;
if (hdr_info->bus_info_offset == 0)
return;
visorchannel_write(chan, off, info, sizeof(*info));
}
/**
* write_vbus_dev_info() - write the contents of <info> to the struct
* spar_vbus_channel_protocol.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 spar_vbus_headerinfo *hdr_info,
struct ultra_vbus_deviceinfo *info, unsigned int devix)
{
int off =
(sizeof(struct channel_header) + hdr_info->dev_info_offset) +
(hdr_info->device_info_struct_bytes * devix);
if (hdr_info->dev_info_offset == 0)
return;
visorchannel_write(chan, off, info, sizeof(*info));
}
/**
* fix_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 the appropriate slot within the
* vbus channel of the bus instance
* @visordev: struct visor_device for the desired device
*/
static void
fix_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 ultra_vbus_deviceinfo dev_info;
const char *chan_type_name = NULL;
struct spar_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 spar_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 (memcmp(&visordrv->channel_types[i].guid,
&visordev->channel_type_guid,
sizeof(visordrv->channel_types[i].guid)) == 0) {
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);
/*
* Re-write bus+chipset info, because it is possible that this
* was previously written by our evil counterpart, virtpci.
*/
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 res;
struct visor_driver *drv;
struct visor_device *dev;
drv = to_visor_driver(xdev->driver);
dev = to_visor_device(xdev);
if (!drv->probe)
return -ENODEV;
mutex_lock(&dev->visordriver_callback_lock);
dev->being_removed = false;
res = drv->probe(dev);
if (res >= 0) {
/* success: reference kept via unmatched get_device() */
get_device(&dev->device);
fix_vbus_dev_info(dev);
}
mutex_unlock(&dev->visordriver_callback_lock);
return res;
}
/**
* 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)
{
int rc = 0;
if (busreg_rc < 0)
return -ENODEV; /*can't register on a nonexistent bus*/
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
*/
rc = driver_register(&drv->driver);
if (rc < 0)
driver_unregister(&drv->driver);
return rc;
}
EXPORT_SYMBOL_GPL(visorbus_register_visor_driver);
/**
* create_bus_instance() - create a device instance for the visor bus itself
* @dev: struct visor_device indicating the bus instance
*
* Return: 0 for success, otherwise negative errno value indicating reason for
* failure
*/
static int
create_bus_instance(struct visor_device *dev)
{
int id = dev->chipset_bus_no;
int err;
struct spar_vbus_headerinfo *hdr_info;
POSTCODE_LINUX(BUS_CREATE_ENTRY_PC, 0, 0, DIAG_SEVERITY_PRINT);
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);
if (!dev->debugfs_dir) {
err = -ENOMEM;
goto err_hdr_info;
}
dev->debugfs_client_bus_info =
debugfs_create_file("client_bus_info", S_IRUSR | S_IRGRP,
dev->debugfs_dir, dev,
&client_bus_info_debugfs_fops);
if (!dev->debugfs_client_bus_info) {
err = -ENOMEM;
goto err_debugfs_dir;
}
if (device_register(&dev->device) < 0) {
POSTCODE_LINUX(DEVICE_CREATE_FAILURE_PC, 0, id,
DIAG_SEVERITY_ERR);
err = -ENODEV;
goto err_debugfs_created;
}
if (get_vbus_header_info(dev->visorchannel, hdr_info) >= 0) {
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);
} else {
kfree(hdr_info);
}
list_add_tail(&dev->list_all, &list_all_bus_instances);
dev_set_drvdata(&dev->device, dev);
return 0;
err_debugfs_created:
debugfs_remove(dev->debugfs_client_bus_info);
err_debugfs_dir:
debugfs_remove_recursive(dev->debugfs_dir);
err_hdr_info:
kfree(hdr_info);
return err;
}
/**
* remove_bus_instance() - remove a device instance for the visor bus itself
* @dev: struct visor_device indentifying the bus to remove
*/
static void
remove_bus_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.
*/
if (dev->visorchannel) {
visorchannel_destroy(dev->visorchannel);
dev->visorchannel = NULL;
}
kfree(dev->vbus_hdr_info);
list_del(&dev->list_all);
device_unregister(&dev->device);
}
/**
* create_bus_type() - create and register the one-and-only one instance of
* the visor bus type (visorbus_type)
* Return: 0 for success, otherwise negative errno value returned by
* bus_register() indicating the reason for failure
*/
static int
create_bus_type(void)
{
busreg_rc = bus_register(&visorbus_type);
return busreg_rc;
}
/**
* remove_bus_type() - remove the one-and-only one instance of the visor bus
* type (visorbus_type)
*/
static void
remove_bus_type(void)
{
bus_unregister(&visorbus_type);
}
/**
* remove_all_visor_devices() - remove all child visor bus 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 = list_entry(listentry,
struct visor_device,
list_all);
remove_visor_device(dev);
}
}
void
chipset_bus_create(struct visor_device *dev)
{
int rc;
u32 bus_no = dev->chipset_bus_no;
POSTCODE_LINUX(BUS_CREATE_ENTRY_PC, 0, bus_no, DIAG_SEVERITY_PRINT);
rc = create_bus_instance(dev);
POSTCODE_LINUX(BUS_CREATE_EXIT_PC, 0, bus_no, DIAG_SEVERITY_PRINT);
if (rc < 0)
POSTCODE_LINUX(BUS_CREATE_FAILURE_PC, 0, bus_no,
DIAG_SEVERITY_ERR);
else
POSTCODE_LINUX(CHIPSET_INIT_SUCCESS_PC, 0, bus_no,
DIAG_SEVERITY_PRINT);
bus_create_response(dev, rc);
}
void
chipset_bus_destroy(struct visor_device *dev)
{
remove_bus_instance(dev);
bus_destroy_response(dev, 0);
}
void
chipset_device_create(struct visor_device *dev_info)
{
int rc;
u32 bus_no = dev_info->chipset_bus_no;
u32 dev_no = dev_info->chipset_dev_no;
POSTCODE_LINUX(DEVICE_CREATE_ENTRY_PC, dev_no, bus_no,
DIAG_SEVERITY_PRINT);
rc = create_visor_device(dev_info);
device_create_response(dev_info, rc);
if (rc < 0)
POSTCODE_LINUX(DEVICE_CREATE_FAILURE_PC, dev_no, bus_no,
DIAG_SEVERITY_ERR);
else
POSTCODE_LINUX(DEVICE_CREATE_SUCCESS_PC, dev_no, bus_no,
DIAG_SEVERITY_PRINT);
}
void
chipset_device_destroy(struct visor_device *dev_info)
{
remove_visor_device(dev_info);
device_destroy_response(dev_info, 0);
}
/**
* 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;
device_pause_response(dev, status);
}
/**
* 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.
*/
device_resume_response(dev, status);
}
/**
* initiate_chipset_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 void
initiate_chipset_device_pause_resume(struct visor_device *dev, bool is_pause)
{
int rc;
struct visor_driver *drv = NULL;
void (*notify_func)(struct visor_device *dev, int response) = NULL;
if (is_pause)
notify_func = device_pause_response;
else
notify_func = device_resume_response;
if (!notify_func)
return;
drv = to_visor_driver(dev->device.driver);
if (!drv) {
(*notify_func)(dev, -ENODEV);
return;
}
if (dev->pausing || dev->resuming) {
(*notify_func)(dev, -EBUSY);
return;
}
/*
* Note that even though both drv->pause() and drv->resume
* specify a callback function, it is NOT necessary for us to
* increment our local module usage count. Reason is, there
* is already a linkage dependency between child function
* drivers and visorbus, so it is already IMPOSSIBLE to unload
* visorbus while child function drivers are still running.
*/
if (is_pause) {
if (!drv->pause) {
(*notify_func)(dev, -EINVAL);
return;
}
dev->pausing = true;
rc = drv->pause(dev, pause_state_change_complete);
} else {
/* This should be done at BUS resume time, but an
* existing problem prevents us from ever getting a bus
* resume... This hack would fail to work should we
* ever have a bus that contains NO devices, since we
* would never even get here in that case.
*/
fix_vbus_dev_info(dev);
if (!drv->resume) {
(*notify_func)(dev, -EINVAL);
return;
}
dev->resuming = true;
rc = drv->resume(dev, resume_state_change_complete);
}
if (rc < 0) {
if (is_pause)
dev->pausing = false;
else
dev->resuming = false;
(*notify_func)(dev, -EINVAL);
}
}
/**
* chipset_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().
*/
void
chipset_device_pause(struct visor_device *dev_info)
{
initiate_chipset_device_pause_resume(dev_info, true);
}
/**
* chipset_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().
*/
void
chipset_device_resume(struct visor_device *dev_info)
{
initiate_chipset_device_pause_resume(dev_info, false);
}
int
visorbus_init(void)
{
int err;
POSTCODE_LINUX(DRIVER_ENTRY_PC, 0, 0, DIAG_SEVERITY_PRINT);
visorbus_debugfs_dir = debugfs_create_dir("visorbus", NULL);
if (!visorbus_debugfs_dir)
return -ENOMEM;
bus_device_info_init(&clientbus_driverinfo, "clientbus", "visorbus");
err = create_bus_type();
if (err < 0) {
POSTCODE_LINUX(BUS_CREATE_ENTRY_PC, 0, 0, DIAG_SEVERITY_ERR);
goto error;
}
bus_device_info_init(&chipset_driverinfo, "chipset", "visorchipset");
return 0;
error:
POSTCODE_LINUX(CHIPSET_INIT_FAILURE_PC, 0, err, DIAG_SEVERITY_ERR);
return err;
}
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 = list_entry(listentry,
struct visor_device,
list_all);
remove_bus_instance(dev);
}
remove_bus_type();
debugfs_remove_recursive(visorbus_debugfs_dir);
}
module_param_named(forcematch, visorbus_forcematch, int, S_IRUGO);
MODULE_PARM_DESC(visorbus_forcematch,
"1 to force a successful dev <--> drv match");
module_param_named(forcenomatch, visorbus_forcenomatch, int, S_IRUGO);
MODULE_PARM_DESC(visorbus_forcenomatch,
"1 to force an UNsuccessful dev <--> drv match");
|