2 * Copyright (c) 2012, Microsoft Corporation.
5 * K. Y. Srinivasan <kys@microsoft.com>
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 as published
9 * by the Free Software Foundation.
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
19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21 #include <linux/kernel.h>
22 #include <linux/mman.h>
23 #include <linux/delay.h>
24 #include <linux/init.h>
25 #include <linux/module.h>
26 #include <linux/slab.h>
27 #include <linux/kthread.h>
28 #include <linux/completion.h>
29 #include <linux/memory_hotplug.h>
30 #include <linux/memory.h>
31 #include <linux/notifier.h>
32 #include <linux/mman.h>
33 #include <linux/percpu_counter.h>
35 #include <linux/hyperv.h>
38 * We begin with definitions supporting the Dynamic Memory protocol
41 * Begin protocol definitions.
47 * Protocol versions. The low word is the minor version, the high word the major
52 * Changed to 0.1 on 2009/03/25
53 * Changes to 0.2 on 2009/05/14
54 * Changes to 0.3 on 2009/12/03
55 * Changed to 1.0 on 2011/04/05
58 #define DYNMEM_MAKE_VERSION(Major, Minor) ((__u32)(((Major) << 16) | (Minor)))
59 #define DYNMEM_MAJOR_VERSION(Version) ((__u32)(Version) >> 16)
60 #define DYNMEM_MINOR_VERSION(Version) ((__u32)(Version) & 0xff)
63 DYNMEM_PROTOCOL_VERSION_1
= DYNMEM_MAKE_VERSION(0, 3),
64 DYNMEM_PROTOCOL_VERSION_2
= DYNMEM_MAKE_VERSION(1, 0),
66 DYNMEM_PROTOCOL_VERSION_WIN7
= DYNMEM_PROTOCOL_VERSION_1
,
67 DYNMEM_PROTOCOL_VERSION_WIN8
= DYNMEM_PROTOCOL_VERSION_2
,
69 DYNMEM_PROTOCOL_VERSION_CURRENT
= DYNMEM_PROTOCOL_VERSION_WIN8
78 enum dm_message_type
{
83 DM_VERSION_REQUEST
= 1,
84 DM_VERSION_RESPONSE
= 2,
85 DM_CAPABILITIES_REPORT
= 3,
86 DM_CAPABILITIES_RESPONSE
= 4,
88 DM_BALLOON_REQUEST
= 6,
89 DM_BALLOON_RESPONSE
= 7,
90 DM_UNBALLOON_REQUEST
= 8,
91 DM_UNBALLOON_RESPONSE
= 9,
92 DM_MEM_HOT_ADD_REQUEST
= 10,
93 DM_MEM_HOT_ADD_RESPONSE
= 11,
94 DM_VERSION_03_MAX
= 11,
104 * Structures defining the dynamic memory management
126 union dm_mem_page_range
{
129 * The PFN number of the first page in the range.
130 * 40 bits is the architectural limit of a PFN
135 * The number of pages in the range.
145 * The header for all dynamic memory messages:
147 * type: Type of the message.
148 * size: Size of the message in bytes; including the header.
149 * trans_id: The guest is responsible for manufacturing this ID.
159 * A generic message format for dynamic memory.
160 * Specific message formats are defined later in the file.
164 struct dm_header hdr
;
165 __u8 data
[]; /* enclosed message */
170 * Specific message types supporting the dynamic memory protocol.
174 * Version negotiation message. Sent from the guest to the host.
175 * The guest is free to try different versions until the host
176 * accepts the version.
178 * dm_version: The protocol version requested.
179 * is_last_attempt: If TRUE, this is the last version guest will request.
180 * reservedz: Reserved field, set to zero.
183 struct dm_version_request
{
184 struct dm_header hdr
;
185 union dm_version version
;
186 __u32 is_last_attempt
:1;
191 * Version response message; Host to Guest and indicates
192 * if the host has accepted the version sent by the guest.
194 * is_accepted: If TRUE, host has accepted the version and the guest
195 * should proceed to the next stage of the protocol. FALSE indicates that
196 * guest should re-try with a different version.
198 * reservedz: Reserved field, set to zero.
201 struct dm_version_response
{
202 struct dm_header hdr
;
208 * Message reporting capabilities. This is sent from the guest to the
212 struct dm_capabilities
{
213 struct dm_header hdr
;
216 __u64 max_page_number
;
220 * Response to the capabilities message. This is sent from the host to the
221 * guest. This message notifies if the host has accepted the guest's
222 * capabilities. If the host has not accepted, the guest must shutdown
225 * is_accepted: Indicates if the host has accepted guest's capabilities.
226 * reservedz: Must be 0.
229 struct dm_capabilities_resp_msg
{
230 struct dm_header hdr
;
236 * This message is used to report memory pressure from the guest.
237 * This message is not part of any transaction and there is no
238 * response to this message.
240 * num_avail: Available memory in pages.
241 * num_committed: Committed memory in pages.
242 * page_file_size: The accumulated size of all page files
243 * in the system in pages.
244 * zero_free: The nunber of zero and free pages.
245 * page_file_writes: The writes to the page file in pages.
246 * io_diff: An indicator of file cache efficiency or page file activity,
247 * calculated as File Cache Page Fault Count - Page Read Count.
248 * This value is in pages.
250 * Some of these metrics are Windows specific and fortunately
251 * the algorithm on the host side that computes the guest memory
252 * pressure only uses num_committed value.
256 struct dm_header hdr
;
259 __u64 page_file_size
;
261 __u32 page_file_writes
;
267 * Message to ask the guest to allocate memory - balloon up message.
268 * This message is sent from the host to the guest. The guest may not be
269 * able to allocate as much memory as requested.
271 * num_pages: number of pages to allocate.
275 struct dm_header hdr
;
282 * Balloon response message; this message is sent from the guest
283 * to the host in response to the balloon message.
285 * reservedz: Reserved; must be set to zero.
286 * more_pages: If FALSE, this is the last message of the transaction.
287 * if TRUE there will atleast one more message from the guest.
289 * range_count: The number of ranges in the range array.
291 * range_array: An array of page ranges returned to the host.
295 struct dm_balloon_response
{
296 struct dm_header hdr
;
299 __u32 range_count
:31;
300 union dm_mem_page_range range_array
[];
304 * Un-balloon message; this message is sent from the host
305 * to the guest to give guest more memory.
307 * more_pages: If FALSE, this is the last message of the transaction.
308 * if TRUE there will atleast one more message from the guest.
310 * reservedz: Reserved; must be set to zero.
312 * range_count: The number of ranges in the range array.
314 * range_array: An array of page ranges returned to the host.
318 struct dm_unballoon_request
{
319 struct dm_header hdr
;
323 union dm_mem_page_range range_array
[];
327 * Un-balloon response message; this message is sent from the guest
328 * to the host in response to an unballoon request.
332 struct dm_unballoon_response
{
333 struct dm_header hdr
;
338 * Hot add request message. Message sent from the host to the guest.
340 * mem_range: Memory range to hot add.
342 * On Linux we currently don't support this since we cannot hot add
343 * arbitrary granularity of memory.
347 struct dm_header hdr
;
348 union dm_mem_page_range range
;
352 * Hot add response message.
353 * This message is sent by the guest to report the status of a hot add request.
354 * If page_count is less than the requested page count, then the host should
355 * assume all further hot add requests will fail, since this indicates that
356 * the guest has hit an upper physical memory barrier.
358 * Hot adds may also fail due to low resources; in this case, the guest must
359 * not complete this message until the hot add can succeed, and the host must
360 * not send a new hot add request until the response is sent.
361 * If VSC fails to hot add memory DYNMEM_NUMBER_OF_UNSUCCESSFUL_HOTADD_ATTEMPTS
362 * times it fails the request.
365 * page_count: number of pages that were successfully hot added.
367 * result: result of the operation 1: success, 0: failure.
371 struct dm_hot_add_response
{
372 struct dm_header hdr
;
378 * Types of information sent from host to the guest.
382 INFO_TYPE_MAX_PAGE_CNT
= 0,
388 * Header for the information message.
391 struct dm_info_header
{
392 enum dm_info_type type
;
397 * This message is sent from the host to the guest to pass
398 * some relevant information (win8 addition).
401 * info_size: size of the information blob.
402 * info: information blob.
406 struct dm_info_header header
;
413 * End protocol definitions.
417 static bool do_hot_add
;
419 module_param(hot_add
, bool, (S_IRUGO
| S_IWUSR
));
420 MODULE_PARM_DESC(hot_add
, "If set attempt memory hot_add");
422 static atomic_t trans_id
= ATOMIC_INIT(0);
424 static int dm_ring_size
= (5 * PAGE_SIZE
);
427 * Driver specific state.
440 static __u8 recv_buffer
[PAGE_SIZE
];
441 static __u8
*send_buffer
;
442 #define PAGES_IN_2M 512
444 struct hv_dynmem_device
{
445 struct hv_device
*dev
;
446 enum hv_dm_state state
;
447 struct completion host_event
;
448 struct completion config_event
;
451 * Number of pages we have currently ballooned out.
453 unsigned int num_pages_ballooned
;
456 * This thread handles both balloon/hot-add
457 * requests from the host as well as notifying
458 * the host with regards to memory pressure in
461 struct task_struct
*thread
;
464 * We start with the highest version we can support
465 * and downgrade based on the host; we save here the
466 * next version to try.
471 static struct hv_dynmem_device dm_device
;
473 static void hot_add_req(struct hv_dynmem_device
*dm
, struct dm_hot_add
*msg
)
476 struct dm_hot_add_response resp
;
480 pr_info("Memory hot add not supported\n");
483 * Currently we do not support hot add.
484 * Just fail the request.
488 memset(&resp
, 0, sizeof(struct dm_hot_add_response
));
489 resp
.hdr
.type
= DM_MEM_HOT_ADD_RESPONSE
;
490 resp
.hdr
.size
= sizeof(struct dm_hot_add_response
);
491 resp
.hdr
.trans_id
= atomic_inc_return(&trans_id
);
496 dm
->state
= DM_INITIALIZED
;
497 vmbus_sendpacket(dm
->dev
->channel
, &resp
,
498 sizeof(struct dm_hot_add_response
),
500 VM_PKT_DATA_INBAND
, 0);
504 static void process_info(struct hv_dynmem_device
*dm
, struct dm_info_msg
*msg
)
506 switch (msg
->header
.type
) {
507 case INFO_TYPE_MAX_PAGE_CNT
:
508 pr_info("Received INFO_TYPE_MAX_PAGE_CNT\n");
509 pr_info("Data Size is %d\n", msg
->header
.data_size
);
512 pr_info("Received Unknown type: %d\n", msg
->header
.type
);
517 * Post our status as it relates memory pressure to the
518 * host. Host expects the guests to post this status
519 * periodically at 1 second intervals.
521 * The metrics specified in this protocol are very Windows
522 * specific and so we cook up numbers here to convey our memory
526 static void post_status(struct hv_dynmem_device
*dm
)
528 struct dm_status status
;
531 memset(&status
, 0, sizeof(struct dm_status
));
532 status
.hdr
.type
= DM_STATUS_REPORT
;
533 status
.hdr
.size
= sizeof(struct dm_status
);
534 status
.hdr
.trans_id
= atomic_inc_return(&trans_id
);
537 status
.num_committed
= vm_memory_committed();
539 vmbus_sendpacket(dm
->dev
->channel
, &status
,
540 sizeof(struct dm_status
),
542 VM_PKT_DATA_INBAND
, 0);
548 static void free_balloon_pages(struct hv_dynmem_device
*dm
,
549 union dm_mem_page_range
*range_array
)
551 int num_pages
= range_array
->finfo
.page_cnt
;
552 __u64 start_frame
= range_array
->finfo
.start_page
;
556 for (i
= 0; i
< num_pages
; i
++) {
557 pg
= pfn_to_page(i
+ start_frame
);
559 dm
->num_pages_ballooned
--;
565 static int alloc_balloon_pages(struct hv_dynmem_device
*dm
, int num_pages
,
566 struct dm_balloon_response
*bl_resp
, int alloc_unit
,
572 if (num_pages
< alloc_unit
)
575 for (i
= 0; (i
* alloc_unit
) < num_pages
; i
++) {
576 if (bl_resp
->hdr
.size
+ sizeof(union dm_mem_page_range
) >
578 return i
* alloc_unit
;
581 * We execute this code in a thread context. Furthermore,
582 * we don't want the kernel to try too hard.
584 pg
= alloc_pages(GFP_HIGHUSER
| __GFP_NORETRY
|
585 __GFP_NOMEMALLOC
| __GFP_NOWARN
,
586 get_order(alloc_unit
<< PAGE_SHIFT
));
590 return i
* alloc_unit
;
594 dm
->num_pages_ballooned
+= alloc_unit
;
596 bl_resp
->range_count
++;
597 bl_resp
->range_array
[i
].finfo
.start_page
=
599 bl_resp
->range_array
[i
].finfo
.page_cnt
= alloc_unit
;
600 bl_resp
->hdr
.size
+= sizeof(union dm_mem_page_range
);
609 static void balloon_up(struct hv_dynmem_device
*dm
, struct dm_balloon
*req
)
611 int num_pages
= req
->num_pages
;
612 int num_ballooned
= 0;
613 struct dm_balloon_response
*bl_resp
;
616 bool alloc_error
= false;
622 * Currently, we only support 4k allocations.
627 bl_resp
= (struct dm_balloon_response
*)send_buffer
;
628 memset(send_buffer
, 0, PAGE_SIZE
);
629 bl_resp
->hdr
.type
= DM_BALLOON_RESPONSE
;
630 bl_resp
->hdr
.trans_id
= atomic_inc_return(&trans_id
);
631 bl_resp
->hdr
.size
= sizeof(struct dm_balloon_response
);
632 bl_resp
->more_pages
= 1;
635 num_pages
-= num_ballooned
;
636 num_ballooned
= alloc_balloon_pages(dm
, num_pages
,
640 if ((alloc_error
) || (num_ballooned
== num_pages
)) {
641 bl_resp
->more_pages
= 0;
643 dm
->state
= DM_INITIALIZED
;
647 * We are pushing a lot of data through the channel;
648 * deal with transient failures caused because of the
649 * lack of space in the ring buffer.
653 ret
= vmbus_sendpacket(dm_device
.dev
->channel
,
657 VM_PKT_DATA_INBAND
, 0);
662 } while (ret
== -EAGAIN
);
666 * Free up the memory we allocatted.
668 pr_info("Balloon response failed\n");
670 for (i
= 0; i
< bl_resp
->range_count
; i
++)
671 free_balloon_pages(dm
,
672 &bl_resp
->range_array
[i
]);
680 static void balloon_down(struct hv_dynmem_device
*dm
,
681 struct dm_unballoon_request
*req
)
683 union dm_mem_page_range
*range_array
= req
->range_array
;
684 int range_count
= req
->range_count
;
685 struct dm_unballoon_response resp
;
688 for (i
= 0; i
< range_count
; i
++)
689 free_balloon_pages(dm
, &range_array
[i
]);
691 if (req
->more_pages
== 1)
694 memset(&resp
, 0, sizeof(struct dm_unballoon_response
));
695 resp
.hdr
.type
= DM_UNBALLOON_RESPONSE
;
696 resp
.hdr
.trans_id
= atomic_inc_return(&trans_id
);
697 resp
.hdr
.size
= sizeof(struct dm_unballoon_response
);
699 vmbus_sendpacket(dm_device
.dev
->channel
, &resp
,
700 sizeof(struct dm_unballoon_response
),
702 VM_PKT_DATA_INBAND
, 0);
704 dm
->state
= DM_INITIALIZED
;
707 static void balloon_onchannelcallback(void *context
);
709 static int dm_thread_func(void *dm_dev
)
711 struct hv_dynmem_device
*dm
= dm_dev
;
713 unsigned long scan_start
;
715 while (!kthread_should_stop()) {
716 t
= wait_for_completion_timeout(&dm_device
.config_event
, 1*HZ
);
718 * The host expects us to post information on the memory
719 * pressure every second.
725 scan_start
= jiffies
;
728 balloon_up(dm
, (struct dm_balloon
*)recv_buffer
);
732 hot_add_req(dm
, (struct dm_hot_add
*)recv_buffer
);
738 if (!time_in_range(jiffies
, scan_start
, scan_start
+ HZ
))
747 static void version_resp(struct hv_dynmem_device
*dm
,
748 struct dm_version_response
*vresp
)
750 struct dm_version_request version_req
;
753 if (vresp
->is_accepted
) {
755 * We are done; wakeup the
756 * context waiting for version
759 complete(&dm
->host_event
);
763 * If there are more versions to try, continue
764 * with negotiations; if not
765 * shutdown the service since we are not able
766 * to negotiate a suitable version number
769 if (dm
->next_version
== 0)
772 dm
->next_version
= 0;
773 memset(&version_req
, 0, sizeof(struct dm_version_request
));
774 version_req
.hdr
.type
= DM_VERSION_REQUEST
;
775 version_req
.hdr
.size
= sizeof(struct dm_version_request
);
776 version_req
.hdr
.trans_id
= atomic_inc_return(&trans_id
);
777 version_req
.version
.version
= DYNMEM_PROTOCOL_VERSION_WIN7
;
778 version_req
.is_last_attempt
= 1;
780 ret
= vmbus_sendpacket(dm
->dev
->channel
, &version_req
,
781 sizeof(struct dm_version_request
),
783 VM_PKT_DATA_INBAND
, 0);
791 dm
->state
= DM_INIT_ERROR
;
792 complete(&dm
->host_event
);
795 static void cap_resp(struct hv_dynmem_device
*dm
,
796 struct dm_capabilities_resp_msg
*cap_resp
)
798 if (!cap_resp
->is_accepted
) {
799 pr_info("Capabilities not accepted by host\n");
800 dm
->state
= DM_INIT_ERROR
;
802 complete(&dm
->host_event
);
805 static void balloon_onchannelcallback(void *context
)
807 struct hv_device
*dev
= context
;
810 struct dm_message
*dm_msg
;
811 struct dm_header
*dm_hdr
;
812 struct hv_dynmem_device
*dm
= hv_get_drvdata(dev
);
814 memset(recv_buffer
, 0, sizeof(recv_buffer
));
815 vmbus_recvpacket(dev
->channel
, recv_buffer
,
816 PAGE_SIZE
, &recvlen
, &requestid
);
819 dm_msg
= (struct dm_message
*)recv_buffer
;
820 dm_hdr
= &dm_msg
->hdr
;
822 switch (dm_hdr
->type
) {
823 case DM_VERSION_RESPONSE
:
825 (struct dm_version_response
*)dm_msg
);
828 case DM_CAPABILITIES_RESPONSE
:
830 (struct dm_capabilities_resp_msg
*)dm_msg
);
833 case DM_BALLOON_REQUEST
:
834 dm
->state
= DM_BALLOON_UP
;
835 complete(&dm
->config_event
);
838 case DM_UNBALLOON_REQUEST
:
839 dm
->state
= DM_BALLOON_DOWN
;
841 (struct dm_unballoon_request
*)recv_buffer
);
844 case DM_MEM_HOT_ADD_REQUEST
:
845 dm
->state
= DM_HOT_ADD
;
846 complete(&dm
->config_event
);
849 case DM_INFO_MESSAGE
:
850 process_info(dm
, (struct dm_info_msg
*)dm_msg
);
854 pr_err("Unhandled message: type: %d\n", dm_hdr
->type
);
861 static int balloon_probe(struct hv_device
*dev
,
862 const struct hv_vmbus_device_id
*dev_id
)
865 struct dm_version_request version_req
;
866 struct dm_capabilities cap_msg
;
868 do_hot_add
= hot_add
;
871 * First allocate a send buffer.
874 send_buffer
= kmalloc(PAGE_SIZE
, GFP_KERNEL
);
878 ret
= vmbus_open(dev
->channel
, dm_ring_size
, dm_ring_size
, NULL
, 0,
879 balloon_onchannelcallback
, dev
);
885 dm_device
.state
= DM_INITIALIZING
;
886 dm_device
.next_version
= DYNMEM_PROTOCOL_VERSION_WIN7
;
887 init_completion(&dm_device
.host_event
);
888 init_completion(&dm_device
.config_event
);
891 kthread_run(dm_thread_func
, &dm_device
, "hv_balloon");
892 if (IS_ERR(dm_device
.thread
)) {
893 ret
= PTR_ERR(dm_device
.thread
);
897 hv_set_drvdata(dev
, &dm_device
);
899 * Initiate the hand shake with the host and negotiate
900 * a version that the host can support. We start with the
901 * highest version number and go down if the host cannot
904 memset(&version_req
, 0, sizeof(struct dm_version_request
));
905 version_req
.hdr
.type
= DM_VERSION_REQUEST
;
906 version_req
.hdr
.size
= sizeof(struct dm_version_request
);
907 version_req
.hdr
.trans_id
= atomic_inc_return(&trans_id
);
908 version_req
.version
.version
= DYNMEM_PROTOCOL_VERSION_WIN8
;
909 version_req
.is_last_attempt
= 0;
911 ret
= vmbus_sendpacket(dev
->channel
, &version_req
,
912 sizeof(struct dm_version_request
),
915 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED
);
919 t
= wait_for_completion_timeout(&dm_device
.host_event
, 5*HZ
);
926 * If we could not negotiate a compatible version with the host
927 * fail the probe function.
929 if (dm_device
.state
== DM_INIT_ERROR
) {
934 * Now submit our capabilities to the host.
936 memset(&cap_msg
, 0, sizeof(struct dm_capabilities
));
937 cap_msg
.hdr
.type
= DM_CAPABILITIES_REPORT
;
938 cap_msg
.hdr
.size
= sizeof(struct dm_capabilities
);
939 cap_msg
.hdr
.trans_id
= atomic_inc_return(&trans_id
);
941 cap_msg
.caps
.cap_bits
.balloon
= 1;
943 * While we currently don't support hot-add,
944 * we still advertise this capability since the
945 * host requires that guests partcipating in the
946 * dynamic memory protocol support hot add.
948 cap_msg
.caps
.cap_bits
.hot_add
= 1;
951 * Currently the host does not use these
952 * values and we set them to what is done in the
955 cap_msg
.min_page_cnt
= 0;
956 cap_msg
.max_page_number
= -1;
958 ret
= vmbus_sendpacket(dev
->channel
, &cap_msg
,
959 sizeof(struct dm_capabilities
),
962 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED
);
966 t
= wait_for_completion_timeout(&dm_device
.host_event
, 5*HZ
);
973 * If the host does not like our capabilities,
974 * fail the probe function.
976 if (dm_device
.state
== DM_INIT_ERROR
) {
981 dm_device
.state
= DM_INITIALIZED
;
986 kthread_stop(dm_device
.thread
);
989 vmbus_close(dev
->channel
);
993 static int balloon_remove(struct hv_device
*dev
)
995 struct hv_dynmem_device
*dm
= hv_get_drvdata(dev
);
997 if (dm
->num_pages_ballooned
!= 0)
998 pr_warn("Ballooned pages: %d\n", dm
->num_pages_ballooned
);
1000 vmbus_close(dev
->channel
);
1001 kthread_stop(dm
->thread
);
1006 static const struct hv_vmbus_device_id id_table
[] = {
1007 /* Dynamic Memory Class ID */
1008 /* 525074DC-8985-46e2-8057-A307DC18A502 */
1009 { VMBUS_DEVICE(0xdc, 0x74, 0x50, 0X52, 0x85, 0x89, 0xe2, 0x46,
1010 0x80, 0x57, 0xa3, 0x07, 0xdc, 0x18, 0xa5, 0x02)
1015 MODULE_DEVICE_TABLE(vmbus
, id_table
);
1017 static struct hv_driver balloon_drv
= {
1018 .name
= "hv_balloon",
1019 .id_table
= id_table
,
1020 .probe
= balloon_probe
,
1021 .remove
= balloon_remove
,
1024 static int __init
init_balloon_drv(void)
1027 return vmbus_driver_register(&balloon_drv
);
1030 static void exit_balloon_drv(void)
1033 vmbus_driver_unregister(&balloon_drv
);
1036 module_init(init_balloon_drv
);
1037 module_exit(exit_balloon_drv
);
1039 MODULE_DESCRIPTION("Hyper-V Balloon");
1040 MODULE_VERSION(HV_DRV_VERSION
);
1041 MODULE_LICENSE("GPL");