forked from ikwzm/udmabuf
-
Notifications
You must be signed in to change notification settings - Fork 0
/
udmabuf.c
1209 lines (1097 loc) · 40.1 KB
/
udmabuf.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*********************************************************************************
*
* Copyright (C) 2015-2018 Ichiro Kawazome
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
********************************************************************************/
#include <linux/cdev.h>
#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/sched.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/sysctl.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/scatterlist.h>
#include <linux/pagemap.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/version.h>
#include <asm/page.h>
#include <asm/byteorder.h>
#define DRIVER_NAME "udmabuf"
#define DEVICE_NAME_FORMAT "udmabuf%d"
#define DEVICE_MAX_NUM 256
#define UDMABUF_DEBUG 1
#define STATIC_DEVICE_NUM 8
#if defined(CONFIG_ARM) || defined(CONFIG_ARM64)
#define USE_VMA_FAULT 1
#else
#define USE_VMA_FAULT 0
#endif
#if (LINUX_VERSION_CODE >= 0x030B00)
#define USE_DEV_GROUPS 1
#else
#define USE_DEV_GROUPS 0
#endif
#if ((LINUX_VERSION_CODE >= 0x040100) && defined(CONFIG_OF))
#define USE_OF_RESERVED_MEM 1
#else
#define USE_OF_RESERVED_MEM 0
#endif
#if ((LINUX_VERSION_CODE >= 0x040100) && defined(CONFIG_OF))
#define USE_OF_DMA_CONFIG 1
#else
#define USE_OF_DMA_CONFIG 0
#endif
#if (UDMABUF_DEBUG == 1)
#define UDMABUF_DEBUG_CHECK(this,debug) (this->debug)
#else
#define UDMABUF_DEBUG_CHECK(this,debug) (0)
#endif
#if (USE_OF_RESERVED_MEM == 1)
#include <linux/of_reserved_mem.h>
#endif
/**
* sync_mode(synchronous mode) value
*/
#define SYNC_MODE_INVALID (0x00)
#define SYNC_MODE_NONCACHED (0x01)
#define SYNC_MODE_WRITECOMBINE (0x02)
#define SYNC_MODE_DMACOHERENT (0x03)
#define SYNC_MODE_MASK (0x03)
#define SYNC_ALWAYS (0x04)
/**
* _PGPROT_NONCACHED : vm_page_prot value when ((sync_mode & SYNC_MODE_MASK) == SYNC_MODE_NONCACHED )
* _PGPROT_WRITECOMBINE : vm_page_prot value when ((sync_mode & SYNC_MODE_MASK) == SYNC_MODE_WRITECOMBINE)
* _PGPROT_DMACOHERENT : vm_page_prot value when ((sync_mode & SYNC_MODE_MASK) == SYNC_MODE_DMACOHERENT )
*/
#if defined(CONFIG_ARM)
#define _PGPROT_NONCACHED(vm_page_prot) pgprot_noncached(vm_page_prot)
#define _PGPROT_WRITECOMBINE(vm_page_prot) pgprot_writecombine(vm_page_prot)
#define _PGPROT_DMACOHERENT(vm_page_prot) pgprot_dmacoherent(vm_page_prot)
#elif defined(CONFIG_ARM64)
#define _PGPROT_NONCACHED(vm_page_prot) pgprot_writecombine(vm_page_prot)
#define _PGPROT_WRITECOMBINE(vm_page_prot) pgprot_writecombine(vm_page_prot)
#define _PGPROT_DMACOHERENT(vm_page_prot) pgprot_writecombine(vm_page_prot)
#else
#define _PGPROT_NONCACHED(vm_page_prot) pgprot_noncached(vm_page_prot)
#define _PGPROT_WRITECOMBINE(vm_page_prot) pgprot_writecombine(vm_page_prot)
#define _PGPROT_DMACOHERENT(vm_page_prot) pgprot_writecombine(vm_page_prot)
#endif
static struct class* udmabuf_sys_class = NULL;
static DEFINE_IDA( udmabuf_device_ida );
static dev_t udmabuf_device_number = 0;
static int dma_mask_bit = 32;
static int info_enable = 1;
/**
* struct udmabuf_driver_data - Udmabuf driver data structure
*/
struct udmabuf_driver_data {
struct device* sys_dev;
struct device* dma_dev;
struct cdev cdev;
dev_t device_number;
struct mutex sem;
bool is_open;
int size;
size_t alloc_size;
void* virt_addr;
dma_addr_t phys_addr;
int sync_mode;
int sync_offset;
size_t sync_size;
int sync_direction;
bool sync_owner;
int sync_for_cpu;
int sync_for_device;
#if (USE_OF_RESERVED_MEM == 1)
bool of_reserved_mem;
#endif
#if ((UDMABUF_DEBUG == 1) && (USE_VMA_FAULT == 1))
bool debug_vma;
#endif
};
/**
* struct udmabuf_static_device - Udmabuf static device structure
*/
struct udmabuf_static_device {
struct platform_device* pdev;
unsigned int size;
};
struct udmabuf_static_device udmabuf_static_device_list[STATIC_DEVICE_NUM] = {};
/**
* udmabuf_static_device_search()
* @pdev: Handle to the platform device structure.
* @pid: Pointer to device id.
* @psize: Pointer to buffer size.
* Return: 1 = found, 0 = not found
*/
static int udmabuf_static_device_search(struct platform_device *pdev, int* pid, unsigned int* psize)
{
int id;
int found = 0;
for (id = 0; id < STATIC_DEVICE_NUM; id++) {
if ((udmabuf_static_device_list[id].pdev != NULL) &&
(udmabuf_static_device_list[id].pdev == pdev)) {
*pid = id;
*psize = udmabuf_static_device_list[id].size;
found = 1;
break;
}
}
return found;
}
/**
* udmabuf_sync_for_cpu() - call dma_sync_single_for_cpu() when (sync_for_cpu != 0)
* @this: Pointer to the udmabuf driver data structure.
* Return: Success(0)
*/
static int udmabuf_sync_for_cpu(struct udmabuf_driver_data* this)
{
if (this->sync_for_cpu) {
dma_addr_t phys_addr = this->phys_addr + this->sync_offset;
enum dma_data_direction direction;
switch(this->sync_direction) {
case 1 : direction = DMA_TO_DEVICE ; break;
case 2 : direction = DMA_FROM_DEVICE ; break;
default: direction = DMA_BIDIRECTIONAL; break;
}
dma_sync_single_for_cpu(this->dma_dev, phys_addr, this->sync_size, direction);
this->sync_for_cpu = 0;
this->sync_owner = 0;
}
return 0;
}
/**
* udmabuf_sync_for_device() - call dma_sync_single_for_device() when (sync_for_device != 0)
* @this: Pointer to the udmabuf driver data structure.
* Return: Success(0)
*/
static int udmabuf_sync_for_device(struct udmabuf_driver_data* this)
{
if (this->sync_for_device) {
dma_addr_t phys_addr = this->phys_addr + this->sync_offset;
enum dma_data_direction direction;
switch(this->sync_direction) {
case 1 : direction = DMA_TO_DEVICE ; break;
case 2 : direction = DMA_FROM_DEVICE ; break;
default: direction = DMA_BIDIRECTIONAL; break;
}
dma_sync_single_for_device(this->dma_dev, phys_addr, this->sync_size, direction);
this->sync_for_device = 0;
this->sync_owner = 1;
}
return 0;
}
#define DEF_ATTR_SHOW(__attr_name, __format, __value) \
static ssize_t udmabuf_show_ ## __attr_name(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
ssize_t status; \
struct udmabuf_driver_data* this = dev_get_drvdata(dev); \
if (mutex_lock_interruptible(&this->sem) != 0) \
return -ERESTARTSYS; \
status = sprintf(buf, __format, (__value)); \
mutex_unlock(&this->sem); \
return status; \
}
static inline int NO_ACTION(struct udmabuf_driver_data* this){return 0;}
#define DEF_ATTR_SET(__attr_name, __min, __max, __pre_action, __post_action) \
static ssize_t udmabuf_set_ ## __attr_name(struct device *dev, struct device_attribute *attr, const char *buf, size_t size) \
{ \
ssize_t status; \
unsigned long value; \
struct udmabuf_driver_data* this = dev_get_drvdata(dev); \
if (0 != mutex_lock_interruptible(&this->sem)){return -ERESTARTSYS;} \
if (0 != (status = kstrtoul(buf, 10, &value))){ goto failed;} \
if ((value < __min) || (__max < value)) {status = -EINVAL; goto failed;} \
if (0 != (status = __pre_action(this))) { goto failed;} \
this->__attr_name = value; \
if (0 != (status = __post_action(this))) { goto failed;} \
status = size; \
failed: \
mutex_unlock(&this->sem); \
return status; \
}
DEF_ATTR_SHOW(size , "%d\n" , this->size );
DEF_ATTR_SHOW(phys_addr , "%pad\n" , &this->phys_addr );
DEF_ATTR_SHOW(sync_mode , "%d\n" , this->sync_mode );
DEF_ATTR_SET( sync_mode , 0, 7, NO_ACTION, NO_ACTION );
DEF_ATTR_SHOW(sync_offset , "0x%lx\n", (long unsigned int)this->sync_offset );
DEF_ATTR_SET( sync_offset , 0, 0xFFFFFFFF, NO_ACTION, NO_ACTION );
DEF_ATTR_SHOW(sync_size , "%zu\n" , this->sync_size );
DEF_ATTR_SET( sync_size , 0, 0xFFFFFFFF, NO_ACTION, NO_ACTION );
DEF_ATTR_SHOW(sync_direction , "%d\n" , this->sync_direction );
DEF_ATTR_SET( sync_direction , 0, 3, NO_ACTION, NO_ACTION );
DEF_ATTR_SHOW(sync_owner , "%d\n" , this->sync_owner );
DEF_ATTR_SHOW(sync_for_cpu , "%d\n" , this->sync_for_cpu );
DEF_ATTR_SET( sync_for_cpu , 0, 1, NO_ACTION, udmabuf_sync_for_cpu );
DEF_ATTR_SHOW(sync_for_device, "%d\n" , this->sync_for_device );
DEF_ATTR_SET( sync_for_device , 0, 1, NO_ACTION, udmabuf_sync_for_device);
#if ((UDMABUF_DEBUG == 1) && (USE_VMA_FAULT == 1))
DEF_ATTR_SHOW(debug_vma , "%d\n" , this->debug_vma );
DEF_ATTR_SET( debug_vma , 0, 1, NO_ACTION, NO_ACTION );
#endif
static struct device_attribute udmabuf_device_attrs[] = {
__ATTR(size , 0444, udmabuf_show_size , NULL ),
__ATTR(phys_addr , 0444, udmabuf_show_phys_addr , NULL ),
__ATTR(sync_mode , 0664, udmabuf_show_sync_mode , udmabuf_set_sync_mode ),
__ATTR(sync_offset , 0664, udmabuf_show_sync_offset , udmabuf_set_sync_offset ),
__ATTR(sync_size , 0664, udmabuf_show_sync_size , udmabuf_set_sync_size ),
__ATTR(sync_direction , 0664, udmabuf_show_sync_direction , udmabuf_set_sync_direction ),
__ATTR(sync_owner , 0664, udmabuf_show_sync_owner , NULL ),
__ATTR(sync_for_cpu , 0664, udmabuf_show_sync_for_cpu , udmabuf_set_sync_for_cpu ),
__ATTR(sync_for_device, 0664, udmabuf_show_sync_for_device , udmabuf_set_sync_for_device),
#if ((UDMABUF_DEBUG == 1) && (USE_VMA_FAULT == 1))
__ATTR(debug_vma , 0664, udmabuf_show_debug_vma , udmabuf_set_debug_vma ),
#endif
__ATTR_NULL,
};
#if (USE_DEV_GROUPS == 1)
static struct attribute *udmabuf_attrs[] = {
&(udmabuf_device_attrs[0].attr),
&(udmabuf_device_attrs[1].attr),
&(udmabuf_device_attrs[2].attr),
&(udmabuf_device_attrs[3].attr),
&(udmabuf_device_attrs[4].attr),
&(udmabuf_device_attrs[5].attr),
&(udmabuf_device_attrs[6].attr),
&(udmabuf_device_attrs[7].attr),
&(udmabuf_device_attrs[8].attr),
#if ((UDMABUF_DEBUG == 1) && (USE_VMA_FAULT == 1))
&(udmabuf_device_attrs[9].attr),
#endif
NULL
};
static struct attribute_group udmabuf_attr_group = {
.attrs = udmabuf_attrs
};
static const struct attribute_group* udmabuf_attr_groups[] = {
&udmabuf_attr_group,
NULL
};
#define SET_SYS_CLASS_ATTRIBUTES(sys_class) {(sys_class)->dev_groups = udmabuf_attr_groups; }
#else
#define SET_SYS_CLASS_ATTRIBUTES(sys_class) {(sys_class)->dev_attrs = udmabuf_device_attrs;}
#endif
#if (USE_VMA_FAULT == 1)
/**
* udmabuf_driver_vma_open() - This is the driver open function.
* @vma: Pointer to the vm area structure.
* Return: None
*/
static void udmabuf_driver_vma_open(struct vm_area_struct* vma)
{
struct udmabuf_driver_data* this = vma->vm_private_data;
if (UDMABUF_DEBUG_CHECK(this, debug_vma))
dev_info(this->dma_dev, "vma_open(virt_addr=0x%lx, offset=0x%lx)\n", vma->vm_start, vma->vm_pgoff<<PAGE_SHIFT);
}
#endif
#if (USE_VMA_FAULT == 1)
/**
* udmabuf_driver_vma_close() - This is the driver close function.
* @vma: Pointer to the vm area structure.
* Return: None
*/
static void udmabuf_driver_vma_close(struct vm_area_struct* vma)
{
struct udmabuf_driver_data* this = vma->vm_private_data;
if (UDMABUF_DEBUG_CHECK(this, debug_vma))
dev_info(this->dma_dev, "vma_close()\n");
}
#endif
#if (USE_VMA_FAULT == 1)
/**
* _udmabuf_driver_vma_fault() - This is the driver nopage inline function.
* @vma: Pointer to the vm area structure.
* @vfm: Pointer to the vm fault structure.
* Return: Success(=0) or error status(<0).
*/
static inline int _udmabuf_driver_vma_fault(struct vm_area_struct* vma, struct vm_fault* vmf)
{
struct udmabuf_driver_data* this = vma->vm_private_data;
struct page* page_ptr = NULL;
unsigned long offset = vmf->pgoff << PAGE_SHIFT;
unsigned long phys_addr = this->phys_addr + offset;
unsigned long page_frame_num = phys_addr >> PAGE_SHIFT;
unsigned long request_size = 1 << PAGE_SHIFT;
unsigned long available_size = this->alloc_size -offset;
#if (LINUX_VERSION_CODE >= 0x040A00)
if (UDMABUF_DEBUG_CHECK(this, debug_vma))
dev_info(this->dma_dev,
"vma_fault(virt_addr=0x%lx, phys_addr=%pad)\n",
vmf->address,
&phys_addr
);
#else
if (UDMABUF_DEBUG_CHECK(this, debug_vma))
dev_info(this->dma_dev,
"vma_fault(virt_addr=0x%lx, phys_addr=%pad)\n",
(long unsigned int)vmf->virtual_address,
&phys_addr
);
#endif
if (request_size > available_size)
return VM_FAULT_SIGBUS;
if (!pfn_valid(page_frame_num))
return VM_FAULT_SIGBUS;
page_ptr = pfn_to_page(page_frame_num);
get_page(page_ptr);
vmf->page = page_ptr;
return 0;
}
#if (LINUX_VERSION_CODE >= 0x040B00)
/**
* udmabuf_driver_vma_fault() - This is the driver nopage function.
* @vfm: Pointer to the vm fault structure.
* Return: Success(=0) or error status(<0).
*/
static int udmabuf_driver_vma_fault(struct vm_fault* vmf)
{
return _udmabuf_driver_vma_fault(vmf->vma, vmf);
}
#else
/**
* udmabuf_driver_vma_fault() - This is the driver nopage function.
* @vma: Pointer to the vm area structure.
* @vfm: Pointer to the vm fault structure.
* Return: Success(=0) or error status(<0).
*/
static int udmabuf_driver_vma_fault(struct vm_area_struct* vma, struct vm_fault* vmf)
{
return _udmabuf_driver_vma_fault(vma, vmf);
}
#endif
#endif /* #if (USE_VMA_FAULT == 1) */
#if (USE_VMA_FAULT == 1)
/**
*
*/
static const struct vm_operations_struct udmabuf_driver_vm_ops = {
.open = udmabuf_driver_vma_open ,
.close = udmabuf_driver_vma_close,
.fault = udmabuf_driver_vma_fault,
};
#endif
/**
* udmabuf_driver_file_open() - This is the driver open function.
* @inode: Pointer to the inode structure of this device.
* @file: Pointer to the file structure.
* Return: Success(=0) or error status(<0).
*/
static int udmabuf_driver_file_open(struct inode *inode, struct file *file)
{
struct udmabuf_driver_data* this;
int status = 0;
this = container_of(inode->i_cdev, struct udmabuf_driver_data, cdev);
file->private_data = this;
this->is_open = 1;
return status;
}
/**
* udmabuf_driver_file_release() - This is the driver release function.
* @inode: Pointer to the inode structure of this device.
* @file: Pointer to the file structure.
* Return: Success(=0) or error status(<0).
*/
static int udmabuf_driver_file_release(struct inode *inode, struct file *file)
{
struct udmabuf_driver_data* this = file->private_data;
this->is_open = 0;
return 0;
}
/**
* udmabuf_driver_file_mmap() - This is the driver memory map function.
* @file: Pointer to the file structure.
* @vma: Pointer to the vm area structure.
* Return: Success(=0) or error status(<0).
*/
static int udmabuf_driver_file_mmap(struct file *file, struct vm_area_struct* vma)
{
struct udmabuf_driver_data* this = file->private_data;
if ((file->f_flags & O_SYNC) | (this->sync_mode & SYNC_ALWAYS)) {
switch (this->sync_mode & SYNC_MODE_MASK) {
case SYNC_MODE_NONCACHED :
vma->vm_flags |= VM_IO;
vma->vm_page_prot = _PGPROT_NONCACHED(vma->vm_page_prot);
break;
case SYNC_MODE_WRITECOMBINE :
vma->vm_flags |= VM_IO;
vma->vm_page_prot = _PGPROT_WRITECOMBINE(vma->vm_page_prot);
break;
case SYNC_MODE_DMACOHERENT :
vma->vm_flags |= VM_IO;
vma->vm_page_prot = _PGPROT_DMACOHERENT(vma->vm_page_prot);
break;
default :
break;
}
}
vma->vm_private_data = this;
vma->vm_pgoff = 0;
#if (USE_VMA_FAULT == 1)
{
unsigned long page_frame_num = this->phys_addr >> PAGE_SHIFT;
if (pfn_valid(page_frame_num)) {
vma->vm_ops = &udmabuf_driver_vm_ops;
udmabuf_driver_vma_open(vma);
return 0;
}
}
#endif
return dma_mmap_coherent(this->dma_dev, vma, this->virt_addr, this->phys_addr, this->alloc_size);
}
/**
* udmabuf_driver_file_read() - This is the driver read function.
* @file: Pointer to the file structure.
* @buff: Pointer to the user buffer.
* @count: The number of bytes to be written.
* @ppos: Pointer to the offset value.
* Return: Transferd size.
*/
static ssize_t udmabuf_driver_file_read(struct file* file, char __user* buff, size_t count, loff_t* ppos)
{
struct udmabuf_driver_data* this = file->private_data;
int result = 0;
size_t xfer_size;
size_t remain_size;
dma_addr_t phys_addr;
void* virt_addr;
if (mutex_lock_interruptible(&this->sem))
return -ERESTARTSYS;
if (*ppos >= this->size) {
result = 0;
goto return_unlock;
}
phys_addr = this->phys_addr + *ppos;
virt_addr = this->virt_addr + *ppos;
xfer_size = (*ppos + count >= this->size) ? this->size - *ppos : count;
if ((file->f_flags & O_SYNC) | (this->sync_mode & SYNC_ALWAYS))
dma_sync_single_for_cpu(this->dma_dev, phys_addr, xfer_size, DMA_FROM_DEVICE);
if ((remain_size = copy_to_user(buff, virt_addr, xfer_size)) != 0) {
result = 0;
goto return_unlock;
}
if ((file->f_flags & O_SYNC) | (this->sync_mode & SYNC_ALWAYS))
dma_sync_single_for_device(this->dma_dev, phys_addr, xfer_size, DMA_FROM_DEVICE);
*ppos += xfer_size;
result = xfer_size;
return_unlock:
mutex_unlock(&this->sem);
return result;
}
/**
* udmabuf_driver_file_write() - This is the driver write function.
* @file: Pointer to the file structure.
* @buff: Pointer to the user buffer.
* @count: The number of bytes to be written.
* @ppos: Pointer to the offset value
* Return: Transferd size.
*/
static ssize_t udmabuf_driver_file_write(struct file* file, const char __user* buff, size_t count, loff_t* ppos)
{
struct udmabuf_driver_data* this = file->private_data;
int result = 0;
size_t xfer_size;
size_t remain_size;
dma_addr_t phys_addr;
void* virt_addr;
if (mutex_lock_interruptible(&this->sem))
return -ERESTARTSYS;
if (*ppos >= this->size) {
result = 0;
goto return_unlock;
}
phys_addr = this->phys_addr + *ppos;
virt_addr = this->virt_addr + *ppos;
xfer_size = (*ppos + count >= this->size) ? this->size - *ppos : count;
if ((file->f_flags & O_SYNC) | (this->sync_mode & SYNC_ALWAYS))
dma_sync_single_for_cpu(this->dma_dev, phys_addr, xfer_size, DMA_TO_DEVICE);
if ((remain_size = copy_from_user(virt_addr, buff, xfer_size)) != 0) {
result = 0;
goto return_unlock;
}
if ((file->f_flags & O_SYNC) | (this->sync_mode & SYNC_ALWAYS))
dma_sync_single_for_device(this->dma_dev, phys_addr, xfer_size, DMA_TO_DEVICE);
*ppos += xfer_size;
result = xfer_size;
return_unlock:
mutex_unlock(&this->sem);
return result;
}
/**
* udmabuf_driver_file_llseek() - This is the driver llseek function.
* @file: Pointer to the file structure.
* @offset: File offset to seek.
* @whence: Type of seek.
* Return: The new position.
*/
static loff_t udmabuf_driver_file_llseek(struct file* file, loff_t offset, int whence)
{
struct udmabuf_driver_data* this = file->private_data;
loff_t new_pos;
switch (whence) {
case 0 : /* SEEK_SET */
new_pos = offset;
break;
case 1 : /* SEEK_CUR */
new_pos = file->f_pos + offset;
break;
case 2 : /* SEEK_END */
new_pos = this->size + offset;
break;
default:
return -EINVAL;
}
if (new_pos < 0 ){return -EINVAL;}
if (new_pos > this->size){return -EINVAL;}
file->f_pos = new_pos;
return new_pos;
}
/**
*
*/
static const struct file_operations udmabuf_driver_file_ops = {
.owner = THIS_MODULE,
.open = udmabuf_driver_file_open,
.release = udmabuf_driver_file_release,
.mmap = udmabuf_driver_file_mmap,
.read = udmabuf_driver_file_read,
.write = udmabuf_driver_file_write,
.llseek = udmabuf_driver_file_llseek,
};
/**
* udmabuf_driver_create() - Create udmabuf driver data structure.
* @name: device name or NULL.
* @parent: parent device or NULL.
* @minor: minor_number or -1.
* Return: Pointer to the udmabuf driver data structure or NULL.
*/
static struct udmabuf_driver_data* udmabuf_driver_create(const char* name, struct device* parent, int minor)
{
struct udmabuf_driver_data* this = NULL;
unsigned int done = 0;
const unsigned int DONE_ALLOC_MINOR = (1 << 0);
const unsigned int DONE_CHRDEV_ADD = (1 << 1);
const unsigned int DONE_DEVICE_CREATE = (1 << 3);
/*
* allocate device minor number
*/
{
if ((0 <= minor) && (minor < DEVICE_MAX_NUM)) {
if (ida_simple_get(&udmabuf_device_ida, minor, minor+1, GFP_KERNEL) < 0) {
printk(KERN_ERR "couldn't allocate minor number(=%d).\n", minor);
goto failed;
}
} else if(minor == -1) {
if ((minor = ida_simple_get(&udmabuf_device_ida, 0, DEVICE_MAX_NUM, GFP_KERNEL)) < 0) {
printk(KERN_ERR "couldn't allocate new minor number. return=%d.\n", minor);
goto failed;
}
} else {
printk(KERN_ERR "invalid minor number(=%d), valid range is 0 to %d\n", minor, DEVICE_MAX_NUM-1);
goto failed;
}
done |= DONE_ALLOC_MINOR;
}
/*
* create (udmabuf_driver_data*) this.
*/
{
this = kzalloc(sizeof(*this), GFP_KERNEL);
if (IS_ERR_OR_NULL(this)) {
int retval = PTR_ERR(this);
this = NULL;
printk(KERN_ERR "kzalloc() failed. return=%d\n", retval);
goto failed;
}
}
/*
* set device_number
*/
{
this->device_number = MKDEV(MAJOR(udmabuf_device_number), minor);
}
/*
* register /sys/class/udmabuf/<name>
*/
{
if (name == NULL) {
this->sys_dev = device_create(udmabuf_sys_class,
parent,
this->device_number,
(void *)this,
DEVICE_NAME_FORMAT, MINOR(this->device_number));
} else {
this->sys_dev = device_create(udmabuf_sys_class,
parent,
this->device_number,
(void *)this,
"%s", name);
}
if (IS_ERR_OR_NULL(this->sys_dev)) {
int retval = PTR_ERR(this->sys_dev);
this->sys_dev = NULL;
printk(KERN_ERR "device_create() failed. return=%d\n", retval);
goto failed;
}
done |= DONE_DEVICE_CREATE;
}
/*
* add chrdev.
*/
{
int retval;
cdev_init(&this->cdev, &udmabuf_driver_file_ops);
this->cdev.owner = THIS_MODULE;
if ((retval = cdev_add(&this->cdev, this->device_number, 1)) != 0) {
printk(KERN_ERR "cdev_add() failed. return=%d\n", retval);
goto failed;
}
done |= DONE_CHRDEV_ADD;
}
/*
* initialize other variables.
*/
{
this->size = 0;
this->alloc_size = 0;
this->sync_mode = SYNC_MODE_NONCACHED;
this->sync_offset = 0;
this->sync_size = 0;
this->sync_direction = 0;
this->sync_owner = 0;
this->sync_for_cpu = 0;
this->sync_for_device = 0;
}
#if (USE_OF_RESERVED_MEM == 1)
{
this->of_reserved_mem = 0;
}
#endif
#if ((UDMABUF_DEBUG == 1) && (USE_VMA_FAULT == 1))
{
this->debug_vma = 0;
}
#endif
mutex_init(&this->sem);
/*
* set dma_dev
*/
{
if (parent != NULL)
this->dma_dev = parent;
else
this->dma_dev = this->sys_dev;
if (this->dma_dev->dma_mask == NULL) {
this->dma_dev->dma_mask = &this->dma_dev->coherent_dma_mask;
}
if (dma_set_mask(this->dma_dev, DMA_BIT_MASK(dma_mask_bit)) == 0) {
dma_set_coherent_mask(this->dma_dev, DMA_BIT_MASK(dma_mask_bit));
} else {
printk(KERN_WARNING "dma_set_mask(DMA_BIT_MASK(%d)) failed\n", dma_mask_bit);
dma_set_mask(this->dma_dev, DMA_BIT_MASK(32));
dma_set_coherent_mask(this->dma_dev, DMA_BIT_MASK(32));
}
}
return this;
failed:
if (done & DONE_CHRDEV_ADD ) { cdev_del(&this->cdev); }
if (done & DONE_DEVICE_CREATE) { device_destroy(udmabuf_sys_class, this->device_number);}
if (done & DONE_ALLOC_MINOR ) { ida_simple_remove(&udmabuf_device_ida, minor);}
if (this != NULL) { kfree(this); }
return NULL;
}
/**
* udmabuf_driver_setup() - Setup the udmabuf driver data structure.
* @this: Pointer to the udmabuf driver data structure.
* @size: buffer size.
* Return: Success(=0) or error status(<0).
*/
static int udmabuf_driver_setup(struct udmabuf_driver_data* this, unsigned int size)
{
if (!this)
return -ENODEV;
/*
* setup buffer size and allocation size
*/
this->size = size;
this->sync_size = size;
this->alloc_size = ((size + ((1 << PAGE_SHIFT) - 1)) >> PAGE_SHIFT) << PAGE_SHIFT;
/*
* dma buffer allocation
*/
this->virt_addr = dma_alloc_coherent(this->dma_dev, this->alloc_size, &this->phys_addr, GFP_KERNEL);
if (IS_ERR_OR_NULL(this->virt_addr)) {
int retval = PTR_ERR(this->virt_addr);
printk(KERN_ERR "dma_alloc_coherent() failed. return(%d)\n", retval);
this->virt_addr = NULL;
return (retval == 0) ? -ENOMEM : retval;
}
return 0;
}
/**
* udmabuf_driver_info() - Print infomation the udmabuf driver data structure.
* @this: Pointer to the udmabuf driver data structure.
*/
static void udmabuf_driver_info(struct udmabuf_driver_data* this)
{
dev_info(this->sys_dev, "major number = %d\n" , MAJOR(this->device_number));
dev_info(this->sys_dev, "minor number = %d\n" , MINOR(this->device_number));
dev_info(this->sys_dev, "phys address = %pad\n", &this->phys_addr);
dev_info(this->sys_dev, "buffer size = %zu\n" , this->alloc_size);
#if defined(CONFIG_ARM) || defined(CONFIG_ARM64)
dev_info(this->sys_dev, "dma coherent = %d\n" , is_device_dma_coherent(this->dma_dev));
#endif
}
/**
* udmabuf_driver_destroy() - Remove the udmabuf driver data structure.
* @this: Pointer to the udmabuf driver data structure.
* Return: Success(=0) or error status(<0).
*
* Unregister the device after releasing the resources.
*/
static int udmabuf_driver_destroy(struct udmabuf_driver_data* this)
{
if (!this)
return -ENODEV;
if (this->virt_addr != NULL) {
dma_free_coherent(this->dma_dev, this->alloc_size, this->virt_addr, this->phys_addr);
this->virt_addr = NULL;
}
cdev_del(&this->cdev);
device_destroy(udmabuf_sys_class, this->device_number);
ida_simple_remove(&udmabuf_device_ida, MINOR(this->device_number));
kfree(this);
return 0;
}
/**
* udmabuf_platform_driver_probe() - Probe call for the device.
* @pdev: handle to the platform device structure.
* Return: Success(=0) or error status(<0).
*
* It does all the memory allocation and registration for the device.
*/
static int udmabuf_platform_driver_probe(struct platform_device *pdev)
{
int retval = 0;
unsigned int size = 0;
int minor_number = -1;
struct udmabuf_driver_data* driver_data = NULL;
const char* device_name = NULL;
dev_dbg(&pdev->dev, "driver probe start.\n");
if (udmabuf_static_device_search(pdev, &minor_number, &size) == 0) {
int status;
unsigned int number;
status = of_property_read_u32(pdev->dev.of_node, "size", &size);
if (status != 0) {
dev_err(&pdev->dev, "invalid property size. status=%d\n", status);
retval = -ENODEV;
goto failed;
}
status = of_property_read_u32(pdev->dev.of_node, "minor-number", &number);
minor_number = (status == 0) ? number : -1;
device_name = of_get_property(pdev->dev.of_node, "device-name", NULL);
if (IS_ERR_OR_NULL(device_name)) {
if (minor_number < 0)
device_name = dev_name(&pdev->dev);
else
device_name = NULL;
}
}
/*
* create udmabuf_driver
*/
driver_data = udmabuf_driver_create(device_name, &pdev->dev, minor_number);
if (IS_ERR_OR_NULL(driver_data)) {
retval = PTR_ERR(driver_data);
dev_err(&pdev->dev, "driver create failed. return=%d.\n", retval);
driver_data = NULL;
retval = (retval == 0) ? -EINVAL : retval;
goto failed;
}
dev_set_drvdata(&pdev->dev, driver_data);
/*
* of_dma_configure()
*/
#if (USE_OF_DMA_CONFIG == 1)
#if (LINUX_VERSION_CODE >= 0x040C00)
retval = of_dma_configure(&pdev->dev, pdev->dev.of_node);
if (retval != 0) {
dev_err(&pdev->dev, "of_dma_configure failed. return=%d\n", retval);
goto failed;
}
#else
of_dma_configure(&pdev->dev, NULL);
#endif
#endif
/*
* of_reserved_mem_device_init()
*/
#if (USE_OF_RESERVED_MEM == 1)
if (pdev->dev.of_node != NULL) {
retval = of_reserved_mem_device_init(&pdev->dev);
if (retval == 0) {
driver_data->of_reserved_mem = 1;
} else if (retval != -ENODEV) {
dev_err(&pdev->dev, "of_reserved_mem_device_init failed. return=%d\n", retval);
goto failed;
}
}
#endif
/*
* setup udmabuf_driver
*/
retval = udmabuf_driver_setup(driver_data, size);
if (retval) {
dev_err(&pdev->dev, "driver setup failed. return=%d\n", retval);
goto failed;
}
if (info_enable) {
udmabuf_driver_info(driver_data);
dev_info(&pdev->dev, "driver installed.\n");
}
return 0;
failed:
if (driver_data != NULL) {
int status;
status = udmabuf_driver_destroy(driver_data);
if (status) {
dev_err(&pdev->dev, "driver destroy failed. return=%d.\n", status);
}
#if (USE_OF_RESERVED_MEM == 1)
if (driver_data->of_reserved_mem == 1) {
of_reserved_mem_device_release(&pdev->dev);
}
#endif
}
return retval;
}
/**
* udmabuf_platform_driver_remove() - Remove call for the device.
* @pdev: Handle to the platform device structure.
* Return: Success(=0) or error status(<0).
*
* Unregister the device after releasing the resources.
*/
static int udmabuf_platform_driver_remove(struct platform_device *pdev)
{
struct udmabuf_driver_data* this = dev_get_drvdata(&pdev->dev);
int retval = 0;
dev_dbg(&pdev->dev, "driver remove start.\n");