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  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * Copyright (C) 2010 - 2013 UNISYS CORPORATION
  4 * All rights reserved.
  5 */
  6
  7/*
  8 *  This header file is to be included by other kernel mode components that
  9 *  implement a particular kind of visor_device.  Each of these other kernel
 10 *  mode components is called a visor device driver.  Refer to visortemplate
 11 *  for a minimal sample visor device driver.
 12 *
 13 *  There should be nothing in this file that is private to the visorbus
 14 *  bus implementation itself.
 15 */
 16
 17#ifndef __VISORBUS_H__
 18#define __VISORBUS_H__
 19
 20#include <linux/device.h>
 21
 22#define VISOR_CHANNEL_SIGNATURE ('L' << 24 | 'N' << 16 | 'C' << 8 | 'E')
 23
 24/*
 25 * enum channel_serverstate
 26 * @CHANNELSRV_UNINITIALIZED: Channel is in an undefined state.
 27 * @CHANNELSRV_READY:	      Channel has been initialized by server.
 28 */
 29enum channel_serverstate {
 30	CHANNELSRV_UNINITIALIZED = 0,
 31	CHANNELSRV_READY = 1
 32};
 33
 34/*
 35 * enum channel_clientstate
 36 * @CHANNELCLI_DETACHED:
 37 * @CHANNELCLI_DISABLED:  Client can see channel but is NOT allowed to use it
 38 *			  unless given TBD* explicit request
 39 *			  (should actually be < DETACHED).
 40 * @CHANNELCLI_ATTACHING: Legacy EFI client request for EFI server to attach.
 41 * @CHANNELCLI_ATTACHED:  Idle, but client may want to use channel any time.
 42 * @CHANNELCLI_BUSY:	  Client either wants to use or is using channel.
 43 * @CHANNELCLI_OWNED:	  "No worries" state - client can access channel
 44 *			  anytime.
 45 */
 46enum channel_clientstate {
 47	CHANNELCLI_DETACHED = 0,
 48	CHANNELCLI_DISABLED = 1,
 49	CHANNELCLI_ATTACHING = 2,
 50	CHANNELCLI_ATTACHED = 3,
 51	CHANNELCLI_BUSY = 4,
 52	CHANNELCLI_OWNED = 5
 53};
 54
 55/*
 56 * Values for VISOR_CHANNEL_PROTOCOL.Features: This define exists so that
 57 * a guest can look at the FeatureFlags in the io channel, and configure the
 58 * driver to use interrupts or not based on this setting. All feature bits for
 59 * all channels should be defined here. The io channel feature bits are defined
 60 * below.
 61 */
 62#define VISOR_DRIVER_ENABLES_INTS (0x1ULL << 1)
 63#define VISOR_CHANNEL_IS_POLLING (0x1ULL << 3)
 64#define VISOR_IOVM_OK_DRIVER_DISABLING_INTS (0x1ULL << 4)
 65#define VISOR_DRIVER_DISABLES_INTS (0x1ULL << 5)
 66#define VISOR_DRIVER_ENHANCED_RCVBUF_CHECKING (0x1ULL << 6)
 67
 68/*
 69 * struct channel_header - Common Channel Header
 70 * @signature:	       Signature.
 71 * @legacy_state:      DEPRECATED - being replaced by.
 72 * @header_size:       sizeof(struct channel_header).
 73 * @size:	       Total size of this channel in bytes.
 74 * @features:	       Flags to modify behavior.
 75 * @chtype:	       Channel type: data, bus, control, etc..
 76 * @partition_handle:  ID of guest partition.
 77 * @handle:	       Device number of this channel in client.
 78 * @ch_space_offset:   Offset in bytes to channel specific area.
 79 * @version_id:	       Struct channel_header Version ID.
 80 * @partition_index:   Index of guest partition.
 81 * @zone_uuid:	       Guid of Channel's zone.
 82 * @cli_str_offset:    Offset from channel header to null-terminated
 83 *		       ClientString (0 if ClientString not present).
 84 * @cli_state_boot:    CHANNEL_CLIENTSTATE of pre-boot EFI client of this
 85 *		       channel.
 86 * @cmd_state_cli:     CHANNEL_COMMANDSTATE (overloaded in Windows drivers, see
 87 *		       ServerStateUp, ServerStateDown, etc).
 88 * @cli_state_os:      CHANNEL_CLIENTSTATE of Guest OS client of this channel.
 89 * @ch_characteristic: CHANNEL_CHARACTERISTIC_<xxx>.
 90 * @cmd_state_srv:     CHANNEL_COMMANDSTATE (overloaded in Windows drivers, see
 91 *		       ServerStateUp, ServerStateDown, etc).
 92 * @srv_state:	       CHANNEL_SERVERSTATE.
 93 * @cli_error_boot:    Bits to indicate err states for boot clients, so err
 94 *		       messages can be throttled.
 95 * @cli_error_os:      Bits to indicate err states for OS clients, so err
 96 *		       messages can be throttled.
 97 * @filler:	       Pad out to 128 byte cacheline.
 98 * @recover_channel:   Please add all new single-byte values below here.
 99 */
100struct channel_header {
101	u64 signature;
102	u32 legacy_state;
103	/* SrvState, CliStateBoot, and CliStateOS below */
104	u32 header_size;
105	u64 size;
106	u64 features;
107	guid_t chtype;
108	u64 partition_handle;
109	u64 handle;
110	u64 ch_space_offset;
111	u32 version_id;
112	u32 partition_index;
113	guid_t zone_guid;
114	u32 cli_str_offset;
115	u32 cli_state_boot;
116	u32 cmd_state_cli;
117	u32 cli_state_os;
118	u32 ch_characteristic;
119	u32 cmd_state_srv;
120	u32 srv_state;
121	u8 cli_error_boot;
122	u8 cli_error_os;
123	u8 filler[1];
124	u8 recover_channel;
125} __packed;
126
127#define VISOR_CHANNEL_ENABLE_INTS (0x1ULL << 0)
128
129/*
130 * struct signal_queue_header - Subheader for the Signal Type variation of the
131 *                              Common Channel.
132 * @version:	      SIGNAL_QUEUE_HEADER Version ID.
133 * @chtype:	      Queue type: storage, network.
134 * @size:	      Total size of this queue in bytes.
135 * @sig_base_offset:  Offset to signal queue area.
136 * @features:	      Flags to modify behavior.
137 * @num_sent:	      Total # of signals placed in this queue.
138 * @num_overflows:    Total # of inserts failed due to full queue.
139 * @signal_size:      Total size of a signal for this queue.
140 * @max_slots:        Max # of slots in queue, 1 slot is always empty.
141 * @max_signals:      Max # of signals in queue (MaxSignalSlots-1).
142 * @head:	      Queue head signal #.
143 * @num_received:     Total # of signals removed from this queue.
144 * @tail:	      Queue tail signal.
145 * @reserved1:	      Reserved field.
146 * @reserved2:	      Reserved field.
147 * @client_queue:
148 * @num_irq_received: Total # of Interrupts received. This is incremented by the
149 *		      ISR in the guest windows driver.
150 * @num_empty:	      Number of times that visor_signal_remove is called and
151 *		      returned Empty Status.
152 * @errorflags:	      Error bits set during SignalReinit to denote trouble with
153 *		      client's fields.
154 * @filler:	      Pad out to 64 byte cacheline.
155 */
156struct signal_queue_header {
157	/* 1st cache line */
158	u32 version;
159	u32 chtype;
160	u64 size;
161	u64 sig_base_offset;
162	u64 features;
163	u64 num_sent;
164	u64 num_overflows;
165	u32 signal_size;
166	u32 max_slots;
167	u32 max_signals;
168	u32 head;
169	/* 2nd cache line */
170	u64 num_received;
171	u32 tail;
172	u32 reserved1;
173	u64 reserved2;
174	u64 client_queue;
175	u64 num_irq_received;
176	u64 num_empty;
177	u32 errorflags;
178	u8 filler[12];
179} __packed;
180
181/* VISORCHANNEL Guids */
182/* {414815ed-c58c-11da-95a9-00e08161165f} */
183#define VISOR_VHBA_CHANNEL_GUID \
184	GUID_INIT(0x414815ed, 0xc58c, 0x11da, \
185		  0x95, 0xa9, 0x0, 0xe0, 0x81, 0x61, 0x16, 0x5f)
186#define VISOR_VHBA_CHANNEL_GUID_STR \
187	"414815ed-c58c-11da-95a9-00e08161165f"
188struct visorchipset_state {
189	u32 created:1;
190	u32 attached:1;
191	u32 configured:1;
192	u32 running:1;
193	/* Remaining bits in this 32-bit word are reserved. */
194};
195
196/**
197 * struct visor_device - A device type for things "plugged" into the visorbus
198 *                       bus
199 * @visorchannel:		Points to the channel that the device is
200 *				associated with.
201 * @channel_type_guid:		Identifies the channel type to the bus driver.
202 * @device:			Device struct meant for use by the bus driver
203 *				only.
204 * @list_all:			Used by the bus driver to enumerate devices.
205 * @timer:		        Timer fired periodically to do interrupt-type
206 *				activity.
207 * @being_removed:		Indicates that the device is being removed from
208 *				the bus. Private bus driver use only.
209 * @visordriver_callback_lock:	Used by the bus driver to lock when adding and
210 *				removing devices.
211 * @pausing:			Indicates that a change towards a paused state.
212 *				is in progress. Only modified by the bus driver.
213 * @resuming:			Indicates that a change towards a running state
214 *				is in progress. Only modified by the bus driver.
215 * @chipset_bus_no:		Private field used by the bus driver.
216 * @chipset_dev_no:		Private field used the bus driver.
217 * @state:			Used to indicate the current state of the
218 *				device.
219 * @inst:			Unique GUID for this instance of the device.
220 * @name:			Name of the device.
221 * @pending_msg_hdr:		For private use by bus driver to respond to
222 *				hypervisor requests.
223 * @vbus_hdr_info:		A pointer to header info. Private use by bus
224 *				driver.
225 * @partition_guid:		Indicates client partion id. This should be the
226 *				same across all visor_devices in the current
227 *				guest. Private use by bus driver only.
228 */
229struct visor_device {
230	struct visorchannel *visorchannel;
231	guid_t channel_type_guid;
232	/* These fields are for private use by the bus driver only. */
233	struct device device;
234	struct list_head list_all;
235	struct timer_list timer;
236	bool timer_active;
237	bool being_removed;
238	struct mutex visordriver_callback_lock; /* synchronize probe/remove */
239	bool pausing;
240	bool resuming;
241	u32 chipset_bus_no;
242	u32 chipset_dev_no;
243	struct visorchipset_state state;
244	guid_t inst;
245	u8 *name;
246	struct controlvm_message_header *pending_msg_hdr;
247	void *vbus_hdr_info;
248	guid_t partition_guid;
249	struct dentry *debugfs_dir;
250	struct dentry *debugfs_bus_info;
251};
252
253#define to_visor_device(x) container_of(x, struct visor_device, device)
254
255typedef void (*visorbus_state_complete_func) (struct visor_device *dev,
256					      int status);
257
258/*
259 * This struct describes a specific visor channel, by providing its GUID, name,
260 * and sizes.
261 */
262struct visor_channeltype_descriptor {
263	const guid_t guid;
264	const char *name;
265	u64 min_bytes;
266	u32 version;
267};
268
269/**
270 * struct visor_driver - Information provided by each visor driver when it
271 *                       registers with the visorbus driver
272 * @name:		Name of the visor driver.
273 * @owner:		The module owner.
274 * @channel_types:	Types of channels handled by this driver, ending with
275 *			a zero GUID. Our specialized BUS.match() method knows
276 *			about this list, and uses it to determine whether this
277 *			driver will in fact handle a new device that it has
278 *			detected.
279 * @probe:		Called when a new device comes online, by our probe()
280 *			function specified by driver.probe() (triggered
281 *			ultimately by some call to driver_register(),
282 *			bus_add_driver(), or driver_attach()).
283 * @remove:		Called when a new device is removed, by our remove()
284 *			function specified by driver.remove() (triggered
285 *			ultimately by some call to device_release_driver()).
286 * @channel_interrupt:	Called periodically, whenever there is a possiblity
287 *			that "something interesting" may have happened to the
288 *			channel.
289 * @pause:		Called to initiate a change of the device's state.  If
290 *			the return valu`e is < 0, there was an error and the
291 *			state transition will NOT occur.  If the return value
292 *			is >= 0, then the state transition was INITIATED
293 *			successfully, and complete_func() will be called (or
294 *			was just called) with the final status when either the
295 *			state transition fails or completes successfully.
296 * @resume:		Behaves similar to pause.
297 * @driver:		Private reference to the device driver. For use by bus
298 *			driver only.
299 */
300struct visor_driver {
301	const char *name;
302	struct module *owner;
303	struct visor_channeltype_descriptor *channel_types;
304	int (*probe)(struct visor_device *dev);
305	void (*remove)(struct visor_device *dev);
306	void (*channel_interrupt)(struct visor_device *dev);
307	int (*pause)(struct visor_device *dev,
308		     visorbus_state_complete_func complete_func);
309	int (*resume)(struct visor_device *dev,
310		      visorbus_state_complete_func complete_func);
311
312	/* These fields are for private use by the bus driver only. */
313	struct device_driver driver;
314};
315
316#define to_visor_driver(x) (container_of(x, struct visor_driver, driver))
317
318int visor_check_channel(struct channel_header *ch, struct device *dev,
319			const guid_t *expected_uuid, char *chname,
320			u64 expected_min_bytes,	u32 expected_version,
321			u64 expected_signature);
322
323int visorbus_register_visor_driver(struct visor_driver *drv);
324void visorbus_unregister_visor_driver(struct visor_driver *drv);
325int visorbus_read_channel(struct visor_device *dev,
326			  unsigned long offset, void *dest,
327			  unsigned long nbytes);
328int visorbus_write_channel(struct visor_device *dev,
329			   unsigned long offset, void *src,
330			   unsigned long nbytes);
331int visorbus_enable_channel_interrupts(struct visor_device *dev);
332void visorbus_disable_channel_interrupts(struct visor_device *dev);
333
334int visorchannel_signalremove(struct visorchannel *channel, u32 queue,
335			      void *msg);
336int visorchannel_signalinsert(struct visorchannel *channel, u32 queue,
337			      void *msg);
338bool visorchannel_signalempty(struct visorchannel *channel, u32 queue);
339const guid_t *visorchannel_get_guid(struct visorchannel *channel);
340
341#define BUS_ROOT_DEVICE UINT_MAX
342struct visor_device *visorbus_get_device_by_id(u32 bus_no, u32 dev_no,
343					       struct visor_device *from);
344#endif