diff options
Diffstat (limited to 'drivers/staging/unisys/visorbus/visorbus_main.c')
| -rw-r--r-- | drivers/staging/unisys/visorbus/visorbus_main.c | 1518 |
1 files changed, 1518 insertions, 0 deletions
diff --git a/drivers/staging/unisys/visorbus/visorbus_main.c b/drivers/staging/unisys/visorbus/visorbus_main.c new file mode 100644 index 000000000..6db47196c --- /dev/null +++ b/drivers/staging/unisys/visorbus/visorbus_main.c @@ -0,0 +1,1518 @@ +/* visorbus_main.c + * + * Copyright � 2010 - 2013 UNISYS CORPORATION + * All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or (at + * your option) any later version. + * + * 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/uuid.h> + +#include "visorbus.h" +#include "visorbus_private.h" +#include "version.h" +#include "periodic_work.h" +#include "vbuschannel.h" +#include "guestlinuxdebug.h" +#include "vmcallinterface.h" + +#define MYDRVNAME "visorbus" + +/* module parameters */ +static int visorbus_debug; +static int visorbus_forcematch; +static int visorbus_forcenomatch; +static int visorbus_debugref; +#define SERIALLOOPBACKCHANADDR (100 * 1024 * 1024) + +#define CURRENT_FILE_PC VISOR_BUS_PC_visorbus_main_c +#define POLLJIFFIES_TESTWORK 100 +#define POLLJIFFIES_NORMALCHANNEL 10 + +static int visorbus_uevent(struct device *xdev, struct kobj_uevent_env *env); +static int visorbus_match(struct device *xdev, struct device_driver *xdrv); +static void fix_vbus_dev_info(struct visor_device *visordev); + +/* BUS type attributes + * + * define & implement display of bus attributes under + * /sys/bus/visorbus. + * + */ + +static ssize_t version_show(struct bus_type *bus, char *buf) +{ + return snprintf(buf, PAGE_SIZE, "%s\n", VERSION); +} + +static BUS_ATTR_RO(version); + +static struct attribute *visorbus_bus_attrs[] = { + &bus_attr_version.attr, + NULL, +}; + +static const struct attribute_group visorbus_bus_group = { + .attrs = visorbus_bus_attrs, +}; + +static const struct attribute_group *visorbus_bus_groups[] = { + &visorbus_bus_group, + NULL, +}; + +/** 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, + .bus_groups = visorbus_bus_groups, +}; + +static struct delayed_work periodic_work; + +/* YES, we need 2 workqueues. + * The reason is, workitems on the test queue may need to cancel + * workitems on the other queue. You will be in for trouble if you try to + * do this with workitems queued on the same workqueue. + */ +static struct workqueue_struct *periodic_test_workqueue; +static struct workqueue_struct *periodic_dev_workqueue; +static long long bus_count; /** number of bus instances */ + /** ever-increasing */ + +static void chipset_bus_create(struct visor_device *bus_info); +static void chipset_bus_destroy(struct visor_device *bus_info); +static void chipset_device_create(struct visor_device *dev_info); +static void chipset_device_destroy(struct visor_device *dev_info); +static void chipset_device_pause(struct visor_device *dev_info); +static void chipset_device_resume(struct visor_device *dev_info); + +/** These functions are implemented herein, and are called by the chipset + * driver to notify us about specific events. + */ +static struct visorchipset_busdev_notifiers chipset_notifiers = { + .bus_create = chipset_bus_create, + .bus_destroy = chipset_bus_destroy, + .device_create = chipset_device_create, + .device_destroy = chipset_device_destroy, + .device_pause = chipset_device_pause, + .device_resume = chipset_device_resume, +}; + +/** These functions are implemented in the chipset driver, and we call them + * herein when we want to acknowledge a specific event. + */ +static struct visorchipset_busdev_responders chipset_responders; + +/* 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) +{ + if (add_uevent_var(env, "VERSION=%s", VERSION)) + return -ENOMEM; + return 0; +} + +/* This is called automatically upon adding a visor_device (device_add), or + * adding a visor_driver (visorbus_register_visor_driver), and returns 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 rc = 0; + 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) { + rc = 1; + goto away; + } + if (visorbus_forcenomatch) + goto away; + + if (!drv->channel_types) + goto away; + 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) { + rc = i + 1; + goto away; + } +away: + return rc; +} + +/** This is called when device_unregister() is called for the bus device + * instance, after all other tasks involved with destroying the device + * are complete. + */ +static void +visorbus_release_busdevice(struct device *xdev) +{ + struct visor_device *dev = dev_get_drvdata(xdev); + + dev_set_drvdata(xdev, NULL); + kfree(dev); +} + +/** This is called when device_unregister() is called for each child + * device instance. + */ +static void +visorbus_release_device(struct device *xdev) +{ + struct visor_device *dev = to_visor_device(xdev); + + if (dev->periodic_work) { + visor_periodic_work_destroy(dev->periodic_work); + dev->periodic_work = NULL; + } + if (dev->visorchannel) { + visorchannel_destroy(dev->visorchannel); + dev->visorchannel = NULL; + } + kfree(dev); +} + +/* Implement publishing of device node attributes under: + * + * /sys/bus/visorbus<x>/dev<y>/devmajorminor + * + */ + +#define to_devmajorminor_attr(_attr) \ + container_of(_attr, struct devmajorminor_attribute, attr) +#define to_visor_device_from_kobjdevmajorminor(obj) \ + container_of(obj, struct visor_device, kobjdevmajorminor) + +struct devmajorminor_attribute { + struct attribute attr; + int slot; + ssize_t (*show)(struct visor_device *, int slot, char *buf); + ssize_t (*store)(struct visor_device *, int slot, const char *buf, + size_t count); +}; + +static ssize_t DEVMAJORMINOR_ATTR(struct visor_device *dev, int slot, char *buf) +{ + int maxdevnodes = ARRAY_SIZE(dev->devnodes) / sizeof(dev->devnodes[0]); + + if (slot < 0 || slot >= maxdevnodes) + return 0; + return snprintf(buf, PAGE_SIZE, "%d:%d\n", + dev->devnodes[slot].major, dev->devnodes[slot].minor); +} + +static ssize_t +devmajorminor_attr_show(struct kobject *kobj, struct attribute *attr, char *buf) +{ + struct devmajorminor_attribute *devmajorminor_attr = + to_devmajorminor_attr(attr); + struct visor_device *dev = to_visor_device_from_kobjdevmajorminor(kobj); + ssize_t ret = 0; + + if (devmajorminor_attr->show) + ret = devmajorminor_attr->show(dev, + devmajorminor_attr->slot, buf); + return ret; +} + +static ssize_t +devmajorminor_attr_store(struct kobject *kobj, + struct attribute *attr, const char *buf, size_t count) +{ + struct devmajorminor_attribute *devmajorminor_attr = + to_devmajorminor_attr(attr); + struct visor_device *dev = to_visor_device_from_kobjdevmajorminor(kobj); + ssize_t ret = 0; + + if (devmajorminor_attr->store) + ret = devmajorminor_attr->store(dev, + devmajorminor_attr->slot, + buf, count); + return ret; +} + +static int register_devmajorminor_attributes(struct visor_device *dev); + +static int +devmajorminor_create_file(struct visor_device *dev, const char *name, + int major, int minor) +{ + int maxdevnodes = ARRAY_SIZE(dev->devnodes) / sizeof(dev->devnodes[0]); + struct devmajorminor_attribute *myattr = NULL; + int x = -1, rc = 0, slot = -1; + + register_devmajorminor_attributes(dev); + for (slot = 0; slot < maxdevnodes; slot++) + if (!dev->devnodes[slot].attr) + break; + if (slot == maxdevnodes) { + rc = -ENOMEM; + goto away; + } + myattr = kmalloc(sizeof(*myattr), GFP_KERNEL); + if (!myattr) { + rc = -ENOMEM; + goto away; + } + memset(myattr, 0, sizeof(struct devmajorminor_attribute)); + myattr->show = DEVMAJORMINOR_ATTR; + myattr->store = NULL; + myattr->slot = slot; + myattr->attr.name = name; + myattr->attr.mode = S_IRUGO; + dev->devnodes[slot].attr = myattr; + dev->devnodes[slot].major = major; + dev->devnodes[slot].minor = minor; + x = sysfs_create_file(&dev->kobjdevmajorminor, &myattr->attr); + if (x < 0) { + rc = x; + goto away; + } + kobject_uevent(&dev->device.kobj, KOBJ_ONLINE); +away: + if (rc < 0) { + kfree(myattr); + myattr = NULL; + dev->devnodes[slot].attr = NULL; + } + return rc; +} + +static void +devmajorminor_remove_file(struct visor_device *dev, int slot) +{ + int maxdevnodes = ARRAY_SIZE(dev->devnodes) / sizeof(dev->devnodes[0]); + struct devmajorminor_attribute *myattr = NULL; + + if (slot < 0 || slot >= maxdevnodes) + return; + myattr = (struct devmajorminor_attribute *)(dev->devnodes[slot].attr); + if (!myattr) + return; + sysfs_remove_file(&dev->kobjdevmajorminor, &myattr->attr); + kobject_uevent(&dev->device.kobj, KOBJ_OFFLINE); + dev->devnodes[slot].attr = NULL; + kfree(myattr); +} + +static void +devmajorminor_remove_all_files(struct visor_device *dev) +{ + int i = 0; + int maxdevnodes = ARRAY_SIZE(dev->devnodes) / sizeof(dev->devnodes[0]); + + for (i = 0; i < maxdevnodes; i++) + devmajorminor_remove_file(dev, i); +} + +static const struct sysfs_ops devmajorminor_sysfs_ops = { + .show = devmajorminor_attr_show, + .store = devmajorminor_attr_store, +}; + +static struct kobj_type devmajorminor_kobj_type = { + .sysfs_ops = &devmajorminor_sysfs_ops +}; + +static int +register_devmajorminor_attributes(struct visor_device *dev) +{ + int rc = 0, x = 0; + + if (dev->kobjdevmajorminor.parent) + goto away; /* already registered */ + x = kobject_init_and_add(&dev->kobjdevmajorminor, + &devmajorminor_kobj_type, &dev->device.kobj, + "devmajorminor"); + if (x < 0) { + rc = x; + goto away; + } + + kobject_uevent(&dev->kobjdevmajorminor, KOBJ_ADD); + +away: + return rc; +} + +static void +unregister_devmajorminor_attributes(struct visor_device *dev) +{ + if (!dev->kobjdevmajorminor.parent) + return; /* already unregistered */ + devmajorminor_remove_all_files(dev); + + kobject_del(&dev->kobjdevmajorminor); + kobject_put(&dev->kobjdevmajorminor); + dev->kobjdevmajorminor.parent = NULL; +} + +/* 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%Lx\n", + visorchannel_get_physaddr(vdev->visorchannel)); +} + +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 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%Lx\n", + visorchannel_get_clientpartition(vdev->visorchannel)); +} + +static ssize_t typeguid_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct visor_device *vdev = to_visor_device(dev); + char s[99]; + + if (!vdev->visorchannel) + return 0; + return snprintf(buf, PAGE_SIZE, "%s\n", + visorchannel_id(vdev->visorchannel, s)); +} + +static ssize_t zoneguid_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct visor_device *vdev = to_visor_device(dev); + char s[99]; + + if (!vdev->visorchannel) + return 0; + return snprintf(buf, PAGE_SIZE, "%s\n", + visorchannel_zoneid(vdev->visorchannel, s)); +} + +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(physaddr); +static DEVICE_ATTR_RO(nbytes); +static DEVICE_ATTR_RO(clientpartition); +static DEVICE_ATTR_RO(typeguid); +static DEVICE_ATTR_RO(zoneguid); +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, +}; + +static struct attribute_group channel_attr_grp = { + .name = "channel", + .attrs = channel_attrs, +}; + +static const struct attribute_group *visorbus_dev_groups[] = { + &channel_attr_grp, + NULL +}; + +/* end implementation of specific channel attributes */ + +/* BUS instance attributes + * + * define & implement display of bus attributes under + * /sys/bus/visorbus/busses/visorbus<n>. + * + * This is a bit hoaky because the kernel does not yet have the infrastructure + * to separate bus INSTANCE attributes from bus TYPE attributes... + * so we roll our own. See businst.c / businst.h. + * + */ + +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%Lx\n", 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 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 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%Lx\n", 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%Lx\n", nbytes); +} + +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 ssize_t client_bus_info_show(struct device *dev, + struct device_attribute *attr, + char *buf) { + struct visor_device *vdev = to_visor_device(dev); + struct visorchannel *channel = vdev->visorchannel; + + int i, x, remain = PAGE_SIZE; + unsigned long off; + char *p = buf; + u8 *partition_name; + struct ultra_vbus_deviceinfo dev_info; + + partition_name = ""; + if (channel) { + if (vdev->name) + partition_name = vdev->name; + x = snprintf(p, remain, + "Client device / client driver info for %s partition (vbus #%d):\n", + partition_name, vdev->chipset_dev_no); + p += x; + remain -= x; + x = visorchannel_read(channel, + offsetof(struct + spar_vbus_channel_protocol, + chp_info), + &dev_info, sizeof(dev_info)); + if (x >= 0) { + x = vbuschannel_devinfo_to_string(&dev_info, p, + remain, -1); + p += x; + remain -= x; + } + x = visorchannel_read(channel, + offsetof(struct + spar_vbus_channel_protocol, + bus_info), + &dev_info, sizeof(dev_info)); + if (x >= 0) { + x = vbuschannel_devinfo_to_string(&dev_info, p, + remain, -1); + p += x; + remain -= x; + } + off = offsetof(struct spar_vbus_channel_protocol, dev_info); + i = 0; + while (off + sizeof(dev_info) <= + visorchannel_get_nbytes(channel)) { + x = visorchannel_read(channel, + off, &dev_info, sizeof(dev_info)); + if (x >= 0) { + x = vbuschannel_devinfo_to_string + (&dev_info, p, remain, i); + p += x; + remain -= x; + } + off += sizeof(dev_info); + i++; + } + } + return PAGE_SIZE - remain; +} + +static DEVICE_ATTR_RO(partition_handle); +static DEVICE_ATTR_RO(partition_guid); +static DEVICE_ATTR_RO(partition_name); +static DEVICE_ATTR_RO(channel_addr); +static DEVICE_ATTR_RO(channel_bytes); +static DEVICE_ATTR_RO(channel_id); +static DEVICE_ATTR_RO(client_bus_info); + +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, + &dev_attr_client_bus_info.attr, + NULL +}; + +static struct attribute_group dev_attr_grp = { + .attrs = dev_attrs, +}; + +static const struct attribute_group *visorbus_groups[] = { + &dev_attr_grp, + NULL +}; + +/* DRIVER attributes + * + * define & implement display of driver attributes under + * /sys/bus/visorbus/drivers/<drivername>. + * + */ + +static ssize_t +DRIVER_ATTR_version(struct device_driver *xdrv, char *buf) +{ + struct visor_driver *drv = to_visor_driver(xdrv); + + return snprintf(buf, PAGE_SIZE, "%s\n", drv->version); +} + +static int +register_driver_attributes(struct visor_driver *drv) +{ + int rc; + struct driver_attribute version = + __ATTR(version, S_IRUGO, DRIVER_ATTR_version, NULL); + drv->version_attr = version; + rc = driver_create_file(&drv->driver, &drv->version_attr); + return rc; +} + +static void +unregister_driver_attributes(struct visor_driver *drv) +{ + driver_remove_file(&drv->driver, &drv->version_attr); +} + +static void +dev_periodic_work(void *xdev) +{ + struct visor_device *dev = (struct visor_device *)xdev; + struct visor_driver *drv = to_visor_driver(dev->device.driver); + + down(&dev->visordriver_callback_lock); + if (drv->channel_interrupt) + drv->channel_interrupt(dev); + up(&dev->visordriver_callback_lock); + if (!visor_periodic_work_nextperiod(dev->periodic_work)) + put_device(&dev->device); +} + +static void +dev_start_periodic_work(struct visor_device *dev) +{ + if (dev->being_removed) + return; + /* now up by at least 2 */ + get_device(&dev->device); + if (!visor_periodic_work_start(dev->periodic_work)) + put_device(&dev->device); +} + +static void +dev_stop_periodic_work(struct visor_device *dev) +{ + if (visor_periodic_work_stop(dev->periodic_work)) + put_device(&dev->device); +} + +/** 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. + */ +static int +visordriver_probe_device(struct device *xdev) +{ + int rc; + struct visor_driver *drv; + struct visor_device *dev; + + drv = to_visor_driver(xdev->driver); + dev = to_visor_device(xdev); + down(&dev->visordriver_callback_lock); + dev->being_removed = false; + /* + * ensure that the dev->being_removed flag is cleared before + * we start the probe + */ + wmb(); + get_device(&dev->device); + if (!drv->probe) { + up(&dev->visordriver_callback_lock); + rc = -1; + goto away; + } + rc = drv->probe(dev); + if (rc < 0) + goto away; + + fix_vbus_dev_info(dev); + up(&dev->visordriver_callback_lock); + rc = 0; +away: + if (rc != 0) + put_device(&dev->device); + return rc; +} + +/** This is called when device_unregister() is called for each child device + * instance, to notify the appropriate visorbus_driver that the device is + * going away, and to decrease the reference count of the device. + */ +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); + down(&dev->visordriver_callback_lock); + dev->being_removed = true; + /* + * ensure that the dev->being_removed flag is set before we start the + * actual removal + */ + wmb(); + if (drv) { + if (drv->remove) + drv->remove(dev); + } + up(&dev->visordriver_callback_lock); + dev_stop_periodic_work(dev); + devmajorminor_remove_all_files(dev); + + put_device(&dev->device); + + return 0; +} + +/** A particular type of visor 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(). + * + */ +int visorbus_register_visor_driver(struct visor_driver *drv) +{ + int rc = 0; + + 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) + return rc; + rc = register_driver_attributes(drv); + return rc; +} +EXPORT_SYMBOL_GPL(visorbus_register_visor_driver); + +/** A particular type of visor driver calls this function to unregister + * the driver, i.e., within its module_exit function. + */ +void +visorbus_unregister_visor_driver(struct visor_driver *drv) +{ + unregister_driver_attributes(drv); + driver_unregister(&drv->driver); +} +EXPORT_SYMBOL_GPL(visorbus_unregister_visor_driver); + +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); + +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); + +int +visorbus_clear_channel(struct visor_device *dev, unsigned long offset, u8 ch, + unsigned long nbytes) +{ + return visorchannel_clear(dev->visorchannel, offset, ch, nbytes); +} +EXPORT_SYMBOL_GPL(visorbus_clear_channel); + +int +visorbus_registerdevnode(struct visor_device *dev, + const char *name, int major, int minor) +{ + return devmajorminor_create_file(dev, name, major, minor); +} +EXPORT_SYMBOL_GPL(visorbus_registerdevnode); + +/** We don't really have a real interrupt, so for now we just call the + * interrupt function periodically... + */ +void +visorbus_enable_channel_interrupts(struct visor_device *dev) +{ + dev_start_periodic_work(dev); +} +EXPORT_SYMBOL_GPL(visorbus_enable_channel_interrupts); + +void +visorbus_disable_channel_interrupts(struct visor_device *dev) +{ + dev_stop_periodic_work(dev); +} +EXPORT_SYMBOL_GPL(visorbus_disable_channel_interrupts); + +/** 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. + */ +static int +create_visor_device(struct visor_device *dev) +{ + int rc = -1; + u32 chipset_bus_no = dev->chipset_bus_no; + u32 chipset_dev_no = dev->chipset_dev_no; + + POSTCODE_LINUX_4(DEVICE_CREATE_ENTRY_PC, chipset_dev_no, chipset_bus_no, + POSTCODE_SEVERITY_INFO); + + sema_init(&dev->visordriver_callback_lock, 1); /* unlocked */ + dev->device.bus = &visorbus_type; + dev->device.groups = visorbus_dev_groups; + device_initialize(&dev->device); + dev->device.release = visorbus_release_device; + /* keep a reference just for us (now 2) */ + get_device(&dev->device); + dev->periodic_work = + visor_periodic_work_create(POLLJIFFIES_NORMALCHANNEL, + periodic_dev_workqueue, + dev_periodic_work, + dev, dev_name(&dev->device)); + if (!dev->periodic_work) { + POSTCODE_LINUX_3(DEVICE_CREATE_FAILURE_PC, chipset_dev_no, + DIAG_SEVERITY_ERR); + goto away; + } + + /* 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). + */ + rc = device_add(&dev->device); + if (rc < 0) { + POSTCODE_LINUX_3(DEVICE_ADD_PC, chipset_bus_no, + DIAG_SEVERITY_ERR); + goto away; + } + + rc = register_devmajorminor_attributes(dev); + if (rc < 0) { + POSTCODE_LINUX_3(DEVICE_REGISTER_FAILURE_PC, chipset_dev_no, + DIAG_SEVERITY_ERR); + goto away_register; + } + + list_add_tail(&dev->list_all, &list_all_device_instances); + return 0; + +away_register: + device_unregister(&dev->device); +away: + put_device(&dev->device); + return rc; +} + +static void +remove_visor_device(struct visor_device *dev) +{ + list_del(&dev->list_all); + unregister_devmajorminor_attributes(dev); + put_device(&dev->device); + device_unregister(&dev->device); +} + +static int +get_vbus_header_info(struct visorchannel *chan, + struct spar_vbus_headerinfo *hdr_info) +{ + int rc = -1; + + if (!SPAR_VBUS_CHANNEL_OK_CLIENT(visorchannel_get_header(chan))) + goto away; + if (visorchannel_read(chan, sizeof(struct channel_header), hdr_info, + sizeof(*hdr_info)) < 0) { + goto away; + } + if (hdr_info->struct_bytes < sizeof(struct spar_vbus_headerinfo)) + goto away; + if (hdr_info->device_info_struct_bytes < + sizeof(struct ultra_vbus_deviceinfo)) { + goto away; + } + rc = 0; +away: + return rc; +} + +/* Write the contents of <info> to the struct + * spar_vbus_channel_protocol.chp_info. */ + +static int +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 -1; + + if (visorchannel_write(chan, off, info, sizeof(*info)) < 0) + return -1; + return 0; +} + +/* Write the contents of <info> to the struct + * spar_vbus_channel_protocol.bus_info. */ + +static int +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 -1; + + if (visorchannel_write(chan, off, info, sizeof(*info)) < 0) + return -1; + return 0; +} + +/* Write the contents of <info> to the + * struct spar_vbus_channel_protocol.dev_info[<devix>]. + */ +static int +write_vbus_dev_info(struct visorchannel *chan, + struct spar_vbus_headerinfo *hdr_info, + struct ultra_vbus_deviceinfo *info, 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 -1; + + if (visorchannel_write(chan, off, info, sizeof(*info)) < 0) + return -1; + return 0; +} + +/* 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. + */ +static void +fix_vbus_dev_info(struct visor_device *visordev) +{ + int i; + struct visor_device *bdev; + struct visor_driver *visordrv; + int bus_no = visordev->chipset_bus_no; + int 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; + + hdr_info = (struct spar_vbus_headerinfo *)visordev->vbus_hdr_info; + if (!hdr_info) + return; + + bdev = visorbus_get_device_by_id(bus_no, BUS_ROOT_DEVICE, NULL); + if (!bdev) + 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, visordrv->version, + visordrv->vertag); + 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); +} + +/** Create a device instance for the visor bus itself. + */ +static int +create_bus_instance(struct visor_device *dev) +{ + int rc; + int id = dev->chipset_bus_no; + struct spar_vbus_headerinfo *hdr_info; + + POSTCODE_LINUX_2(BUS_CREATE_ENTRY_PC, POSTCODE_SEVERITY_INFO); + + hdr_info = kzalloc(sizeof(*hdr_info), GFP_KERNEL); + if (!hdr_info) { + rc = -1; + goto away; + } + + dev_set_name(&dev->device, "visorbus%d", id); + dev->device.bus = &visorbus_type; + dev->device.groups = visorbus_groups; + dev->device.release = visorbus_release_busdevice; + + if (device_register(&dev->device) < 0) { + POSTCODE_LINUX_3(DEVICE_CREATE_FAILURE_PC, id, + POSTCODE_SEVERITY_ERR); + rc = -1; + goto away_mem; + } + + 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); + } + bus_count++; + list_add_tail(&dev->list_all, &list_all_bus_instances); + dev_set_drvdata(&dev->device, dev); + return 0; + +away_mem: + kfree(hdr_info); +away: + return rc; +} + +/** Remove a device instance for the visor bus itself. + */ +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. + */ + bus_count--; + 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 and register the one-and-only one instance of + * the visor bus type (visorbus_type). + */ +static int +create_bus_type(void) +{ + int rc = 0; + + rc = bus_register(&visorbus_type); + return rc; +} + +/** 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 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); + } +} + +static void +chipset_bus_create(struct visor_device *dev) +{ + int rc; + u32 bus_no = dev->chipset_bus_no; + + POSTCODE_LINUX_3(BUS_CREATE_ENTRY_PC, bus_no, POSTCODE_SEVERITY_INFO); + rc = create_bus_instance(dev); + POSTCODE_LINUX_3(BUS_CREATE_EXIT_PC, bus_no, POSTCODE_SEVERITY_INFO); + + if (rc < 0) + POSTCODE_LINUX_3(BUS_CREATE_FAILURE_PC, bus_no, + POSTCODE_SEVERITY_ERR); + else + POSTCODE_LINUX_3(CHIPSET_INIT_SUCCESS_PC, bus_no, + POSTCODE_SEVERITY_INFO); + + if (chipset_responders.bus_create) + (*chipset_responders.bus_create) (dev, rc); +} + +static void +chipset_bus_destroy(struct visor_device *dev) +{ + remove_bus_instance(dev); + if (chipset_responders.bus_destroy) + (*chipset_responders.bus_destroy)(dev, 0); +} + +static void +chipset_device_create(struct visor_device *dev_info) +{ + int rc = -1; + u32 bus_no = dev_info->chipset_bus_no; + u32 dev_no = dev_info->chipset_dev_no; + + POSTCODE_LINUX_4(DEVICE_CREATE_ENTRY_PC, dev_no, bus_no, + POSTCODE_SEVERITY_INFO); + + rc = create_visor_device(dev_info); + if (chipset_responders.device_create) + chipset_responders.device_create(dev_info, rc); + + if (rc < 0) + POSTCODE_LINUX_4(DEVICE_CREATE_FAILURE_PC, dev_no, bus_no, + POSTCODE_SEVERITY_ERR); + else + POSTCODE_LINUX_4(DEVICE_CREATE_SUCCESS_PC, dev_no, bus_no, + POSTCODE_SEVERITY_INFO); +} + +static void +chipset_device_destroy(struct visor_device *dev_info) +{ + remove_visor_device(dev_info); + + if (chipset_responders.device_destroy) + (*chipset_responders.device_destroy) (dev_info, 0); +} + +/* This is the callback function specified for a function driver, to + * be called when a pending "pause device" operation has been + * completed. + */ +static void +pause_state_change_complete(struct visor_device *dev, int status) +{ + if (!dev->pausing) + return; + + dev->pausing = false; + if (!chipset_responders.device_pause) /* this can never happen! */ + return; + + /* Notify the chipset driver that the pause is complete, which + * will presumably want to send some sort of response to the + * initiator. */ + (*chipset_responders.device_pause) (dev, status); +} + +/* This is the callback function specified for a function driver, to + * be called when a pending "resume device" operation has been + * completed. + */ +static void +resume_state_change_complete(struct visor_device *dev, int status) +{ + if (!dev->resuming) + return; + + dev->resuming = false; + if (!chipset_responders.device_resume) /* this can never happen! */ + return; + + /* Notify the chipset driver that the resume is complete, + * which will presumably want to send some sort of response to + * the initiator. */ + (*chipset_responders.device_resume) (dev, status); +} + +/* Tell the subordinate function driver for a specific device to pause + * or resume that device. Result is returned asynchronously via a + * callback function. + */ +static void +initiate_chipset_device_pause_resume(struct visor_device *dev, bool is_pause) +{ + int rc = -1, x; + struct visor_driver *drv = NULL; + void (*notify_func)(struct visor_device *dev, int response) = NULL; + + if (is_pause) + notify_func = chipset_responders.device_pause; + else + notify_func = chipset_responders.device_resume; + if (!notify_func) + goto away; + + drv = to_visor_driver(dev->device.driver); + if (!drv) + goto away; + + if (dev->pausing || dev->resuming) + goto away; + + /* 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) + goto away; + + dev->pausing = true; + x = 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) + goto away; + + dev->resuming = true; + x = drv->resume(dev, resume_state_change_complete); + } + if (x < 0) { + if (is_pause) + dev->pausing = false; + else + dev->resuming = false; + goto away; + } + rc = 0; +away: + if (rc < 0) { + if (notify_func) + (*notify_func)(dev, rc); + } +} + +static void +chipset_device_pause(struct visor_device *dev_info) +{ + initiate_chipset_device_pause_resume(dev_info, true); +} + +static void +chipset_device_resume(struct visor_device *dev_info) +{ + initiate_chipset_device_pause_resume(dev_info, false); +} + +struct channel_size_info { + uuid_le guid; + unsigned long min_size; + unsigned long max_size; +}; + +int +visorbus_init(void) +{ + int rc = 0; + + POSTCODE_LINUX_3(DRIVER_ENTRY_PC, rc, POSTCODE_SEVERITY_INFO); + bus_device_info_init(&clientbus_driverinfo, + "clientbus", "visorbus", + VERSION, NULL); + + rc = create_bus_type(); + if (rc < 0) { + POSTCODE_LINUX_2(BUS_CREATE_ENTRY_PC, DIAG_SEVERITY_ERR); + goto away; + } + + periodic_dev_workqueue = create_singlethread_workqueue("visorbus_dev"); + if (!periodic_dev_workqueue) { + POSTCODE_LINUX_2(CREATE_WORKQUEUE_PC, DIAG_SEVERITY_ERR); + rc = -ENOMEM; + goto away; + } + + /* This enables us to receive notifications when devices appear for + * which this service partition is to be a server for. + */ + visorchipset_register_busdev(&chipset_notifiers, + &chipset_responders, + &chipset_driverinfo); + + rc = 0; + +away: + if (rc) + POSTCODE_LINUX_3(CHIPSET_INIT_FAILURE_PC, rc, + POSTCODE_SEVERITY_ERR); + return rc; +} + +void +visorbus_exit(void) +{ + struct list_head *listentry, *listtmp; + + visorchipset_register_busdev(NULL, NULL, NULL); + remove_all_visor_devices(); + + flush_workqueue(periodic_dev_workqueue); /* better not be any work! */ + destroy_workqueue(periodic_dev_workqueue); + periodic_dev_workqueue = NULL; + + if (periodic_test_workqueue) { + cancel_delayed_work(&periodic_work); + flush_workqueue(periodic_test_workqueue); + destroy_workqueue(periodic_test_workqueue); + periodic_test_workqueue = NULL; + } + + 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(); +} + +module_param_named(debug, visorbus_debug, int, S_IRUGO); +MODULE_PARM_DESC(visorbus_debug, "1 to debug"); + +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"); + +module_param_named(debugref, visorbus_debugref, int, S_IRUGO); +MODULE_PARM_DESC(visorbus_debugref, "1 to debug reference counting"); |