drivers/staging/unisys/include/visorbus.h

   1 /* visorbus.h
   2  *
   3  * Copyright (C) 2010 - 2013 UNISYS CORPORATION
   4  * All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or (at
   9  * your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  14  * NON INFRINGEMENT.  See the GNU General Public License for more
  15  * details.
  16  */
  17
  18 /*
  19  *  This header file is to be included by other kernel mode components that
  20  *  implement a particular kind of visor_device.  Each of these other kernel
  21  *  mode components is called a visor device driver.  Refer to visortemplate
  22  *  for a minimal sample visor device driver.
  23  *
  24  *  There should be nothing in this file that is private to the visorbus
  25  *  bus implementation itself.
  26  *
  27  */
  28
  29 #ifndef __VISORBUS_H__
  30 #define __VISORBUS_H__
  31
  32 #include <linux/device.h>
  33 #include <linux/module.h>
  34 #include <linux/poll.h>
  35 #include <linux/kernel.h>
  36 #include <linux/uuid.h>
  37 #include <linux/seq_file.h>
  38 #include <linux/slab.h>
  39
  40 #include "channel.h"
  41
  42 struct visor_driver;
  43 struct visor_device;
  44 extern struct bus_type visorbus_type;
  45
  46 typedef void (*visorbus_state_complete_func) (struct visor_device *dev,
  47                                               int status);
  48 struct visorchipset_state {
  49         u32 created:1;
  50         u32 attached:1;
  51         u32 configured:1;
  52         u32 running:1;
  53         /* Add new fields above. */
  54         /* Remaining bits in this 32-bit word are unused. */
  55 };
  56
  57 /** This struct describes a specific Supervisor channel, by providing its
  58  *  GUID, name, and sizes.
  59  */
  60 struct visor_channeltype_descriptor {
  61         const uuid_le guid;
  62         const char *name;
  63 };
  64
  65 /**
  66  * struct visor_driver - Information provided by each visor driver when it
  67  * registers with the visorbus driver.
  68  * @name:               Name of the visor driver.
  69  * @version:            The numbered version of the driver (x.x.xxx).
  70  * @vertag:             A human readable version string.
  71  * @owner:              The module owner.
  72  * @channel_types:      Types of channels handled by this driver, ending with
  73  *                      a zero GUID. Our specialized BUS.match() method knows
  74  *                      about this list, and uses it to determine whether this
  75  *                      driver will in fact handle a new device that it has
  76  *                      detected.
  77  * @probe:              Called when a new device comes online, by our probe()
  78  *                      function specified by driver.probe() (triggered
  79  *                      ultimately by some call to driver_register(),
  80  *                      bus_add_driver(), or driver_attach()).
  81  * @remove:             Called when a new device is removed, by our remove()
  82  *                      function specified by driver.remove() (triggered
  83  *                      ultimately by some call to device_release_driver()).
  84  * @channel_interrupt:  Called periodically, whenever there is a possiblity
  85  *                      that "something interesting" may have happened to the
  86  *                      channel.
  87  * @pause:              Called to initiate a change of the device's state.  If
  88  *                      the return valu`e is < 0, there was an error and the
  89  *                      state transition will NOT occur.  If the return value
  90  *                      is >= 0, then the state transition was INITIATED
  91  *                      successfully, and complete_func() will be called (or
  92  *                      was just called) with the final status when either the
  93  *                      state transition fails or completes successfully.
  94  * @resume:             Behaves similar to pause.
  95  * @driver:             Private reference to the device driver. For use by bus
  96  *                      driver only.
  97  * @version_attr:       Private version field. For use by bus driver only.
  98  */
  99 struct visor_driver {
 100         const char *name;
 101         const char *version;
 102         const char *vertag;
 103         struct module *owner;
 104         struct visor_channeltype_descriptor *channel_types;
 105         int (*probe)(struct visor_device *dev);
 106         void (*remove)(struct visor_device *dev);
 107         void (*channel_interrupt)(struct visor_device *dev);
 108         int (*pause)(struct visor_device *dev,
 109                      visorbus_state_complete_func complete_func);
 110         int (*resume)(struct visor_device *dev,
 111                       visorbus_state_complete_func complete_func);
 112
 113         /* These fields are for private use by the bus driver only. */
 114         struct device_driver driver;
 115         struct driver_attribute version_attr;
 116 };
 117
 118 #define to_visor_driver(x) ((x) ? \
 119         (container_of(x, struct visor_driver, driver)) : (NULL))
 120
 121 /**
 122  * struct visor_device - A device type for things "plugged" into the visorbus
 123  * bus
 124  * @visorchannel:               Points to the channel that the device is
 125  *                              associated with.
 126  * @channel_type_guid:          Identifies the channel type to the bus driver.
 127  * @device:                     Device struct meant for use by the bus driver
 128  *                              only.
 129  * @list_all:                   Used by the bus driver to enumerate devices.
 130  * @timer:                      Timer fired periodically to do interrupt-type
 131  *                              activity.
 132  * @being_removed:              Indicates that the device is being removed from
 133  *                              the bus. Private bus driver use only.
 134  * @visordriver_callback_lock:  Used by the bus driver to lock when handling
 135  *                              channel events.
 136  * @pausing:                    Indicates that a change towards a paused state.
 137  *                              is in progress. Only modified by the bus driver.
 138  * @resuming:                   Indicates that a change towards a running state
 139  *                              is in progress. Only modified by the bus driver.
 140  * @chipset_bus_no:             Private field used by the bus driver.
 141  * @chipset_dev_no:             Private field used the bus driver.
 142  * @state:                      Used to indicate the current state of the
 143  *                              device.
 144  * @inst:                       Unique GUID for this instance of the device.
 145  * @name:                       Name of the device.
 146  * @pending_msg_hdr:            For private use by bus driver to respond to
 147  *                              hypervisor requests.
 148  * @vbus_hdr_info:              A pointer to header info. Private use by bus
 149  *                              driver.
 150  * @partition_uuid:             Indicates client partion id. This should be the
 151  *                              same across all visor_devices in the current
 152  *                              guest. Private use by bus driver only.
 153  */
 154
 155 struct visor_device {
 156         struct visorchannel *visorchannel;
 157         uuid_le channel_type_guid;
 158         /* These fields are for private use by the bus driver only. */
 159         struct device device;
 160         struct list_head list_all;
 161         struct timer_list timer;
 162         bool timer_active;
 163         bool being_removed;
 164         struct mutex visordriver_callback_lock;
 165         bool pausing;
 166         bool resuming;
 167         u32 chipset_bus_no;
 168         u32 chipset_dev_no;
 169         struct visorchipset_state state;
 170         uuid_le inst;
 171         u8 *name;
 172         struct controlvm_message_header *pending_msg_hdr;
 173         void *vbus_hdr_info;
 174         uuid_le partition_uuid;
 175 };
 176
 177 #define to_visor_device(x) container_of(x, struct visor_device, device)
 178
 179 int visorbus_register_visor_driver(struct visor_driver *);
 180 void visorbus_unregister_visor_driver(struct visor_driver *);
 181 int visorbus_read_channel(struct visor_device *dev,
 182                           unsigned long offset, void *dest,
 183                           unsigned long nbytes);
 184 int visorbus_write_channel(struct visor_device *dev,
 185                            unsigned long offset, void *src,
 186                            unsigned long nbytes);
 187 void visorbus_enable_channel_interrupts(struct visor_device *dev);
 188 void visorbus_disable_channel_interrupts(struct visor_device *dev);
 189
 190 /* Levels of severity for diagnostic events, in order from lowest severity to
 191  * highest (i.e. fatal errors are the most severe, and should always be logged,
 192  * but info events rarely need to be logged except during debugging). The
 193  * values DIAG_SEVERITY_ENUM_BEGIN and DIAG_SEVERITY_ENUM_END are not valid
 194  * severity values.  They exist merely to dilineate the list, so that future
 195  * additions won't require changes to the driver (i.e. when checking for
 196  * out-of-range severities in SetSeverity). The values DIAG_SEVERITY_OVERRIDE
 197  * and DIAG_SEVERITY_SHUTOFF are not valid severity values for logging events
 198  * but they are valid for controlling the amount of event data. Changes made
 199  * to the enum, need to be reflected in s-Par.
 200  */
 201 enum diag_severity {
 202         DIAG_SEVERITY_VERBOSE = 0,
 203         DIAG_SEVERITY_INFO = 1,
 204         DIAG_SEVERITY_WARNING = 2,
 205         DIAG_SEVERITY_ERR = 3,
 206         DIAG_SEVERITY_PRINT = 4,
 207 };
 208
 209 bool visorchannel_signalremove(struct visorchannel *channel, u32 queue,
 210                                void *msg);
 211 bool visorchannel_signalinsert(struct visorchannel *channel, u32 queue,
 212                                void *msg);
 213 bool visorchannel_signalempty(struct visorchannel *channel, u32 queue);
 214 uuid_le visorchannel_get_uuid(struct visorchannel *channel);
 215
 216 #define BUS_ROOT_DEVICE         UINT_MAX
 217 struct visor_device *visorbus_get_device_by_id(u32 bus_no, u32 dev_no,
 218                                                struct visor_device *from);
 219 #endif