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Merge remote-tracking branch 'moduleh/module.h-split'
[linux-2.6/next.git] / arch / arm / mach-bcmring / dma.c
blobb52b8de91bde72c2a4847c1a37a44f425974612d
1 /*****************************************************************************
2 * Copyright 2004 - 2008 Broadcom Corporation. All rights reserved.
3 *
4 * Unless you and Broadcom execute a separate written software license
5 * agreement governing use of this software, this software is licensed to you
6 * under the terms of the GNU General Public License version 2, available at
7 * http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
8 *
9 * Notwithstanding the above, under no circumstances may you combine this
10 * software in any way with any other Broadcom software provided under a
11 * license other than the GPL, without Broadcom's express prior written
12 * consent.
13 *****************************************************************************/
14
15 /****************************************************************************/
16 /**
17 * @file dma.c
18 *
19 * @brief Implements the DMA interface.
20 */
21 /****************************************************************************/
22
23 /* ---- Include Files ---------------------------------------------------- */
24
25 #include <linux/module.h>
26 #include <linux/device.h>
27 #include <linux/dma-mapping.h>
28 #include <linux/interrupt.h>
29 #include <linux/sched.h>
30 #include <linux/irqreturn.h>
31 #include <linux/proc_fs.h>
32 #include <linux/slab.h>
33
34 #include <mach/timer.h>
35
36 #include <linux/mm.h>
37 #include <linux/pfn.h>
38 #include <linux/atomic.h>
39 #include <mach/dma.h>
40
41 /* I don't quite understand why dc4 fails when this is set to 1 and DMA is enabled */
42 /* especially since dc4 doesn't use kmalloc'd memory. */
43
44 #define ALLOW_MAP_OF_KMALLOC_MEMORY 0
45
46 /* ---- Public Variables ------------------------------------------------- */
47
48 /* ---- Private Constants and Types -------------------------------------- */
49
50 #define MAKE_HANDLE(controllerIdx, channelIdx) (((controllerIdx) << 4) | (channelIdx))
51
52 #define CONTROLLER_FROM_HANDLE(handle) (((handle) >> 4) & 0x0f)
53 #define CHANNEL_FROM_HANDLE(handle) ((handle) & 0x0f)
54
55 #define DMA_MAP_DEBUG 0
56
57 #if DMA_MAP_DEBUG
58 # define DMA_MAP_PRINT(fmt, args...) printk("%s: " fmt, __func__, ## args)
59 #else
60 # define DMA_MAP_PRINT(fmt, args...)
61 #endif
62
63 /* ---- Private Variables ------------------------------------------------ */
64
65 static DMA_Global_t gDMA;
66 static struct proc_dir_entry *gDmaDir;
67
68 static atomic_t gDmaStatMemTypeKmalloc = ATOMIC_INIT(0);
69 static atomic_t gDmaStatMemTypeVmalloc = ATOMIC_INIT(0);
70 static atomic_t gDmaStatMemTypeUser = ATOMIC_INIT(0);
71 static atomic_t gDmaStatMemTypeCoherent = ATOMIC_INIT(0);
72
73 #include "dma_device.c"
74
75 /* ---- Private Function Prototypes -------------------------------------- */
76
77 /* ---- Functions ------------------------------------------------------- */
78
79 /****************************************************************************/
80 /**
81 * Displays information for /proc/dma/mem-type
82 */
83 /****************************************************************************/
84
85 static int dma_proc_read_mem_type(char *buf, char **start, off_t offset,
86 int count, int *eof, void *data)
87 {
88 int len = 0;
89
90 len += sprintf(buf + len, "dma_map_mem statistics\n");
91 len +=
92 sprintf(buf + len, "coherent: %d\n",
93 atomic_read(&gDmaStatMemTypeCoherent));
94 len +=
95 sprintf(buf + len, "kmalloc: %d\n",
96 atomic_read(&gDmaStatMemTypeKmalloc));
97 len +=
98 sprintf(buf + len, "vmalloc: %d\n",
99 atomic_read(&gDmaStatMemTypeVmalloc));
100 len +=
101 sprintf(buf + len, "user: %d\n",
102 atomic_read(&gDmaStatMemTypeUser));
103
104 return len;
105 }
106
107 /****************************************************************************/
108 /**
109 * Displays information for /proc/dma/channels
110 */
111 /****************************************************************************/
112
113 static int dma_proc_read_channels(char *buf, char **start, off_t offset,
114 int count, int *eof, void *data)
115 {
116 int controllerIdx;
117 int channelIdx;
118 int limit = count - 200;
119 int len = 0;
120 DMA_Channel_t *channel;
121
122 if (down_interruptible(&gDMA.lock) < 0) {
123 return -ERESTARTSYS;
124 }
125
126 for (controllerIdx = 0; controllerIdx < DMA_NUM_CONTROLLERS;
127 controllerIdx++) {
128 for (channelIdx = 0; channelIdx < DMA_NUM_CHANNELS;
129 channelIdx++) {
130 if (len >= limit) {
131 break;
132 }
133
134 channel =
135 &gDMA.controller[controllerIdx].channel[channelIdx];
136
137 len +=
138 sprintf(buf + len, "%d:%d ", controllerIdx,
139 channelIdx);
140
141 if ((channel->flags & DMA_CHANNEL_FLAG_IS_DEDICATED) !=
142 0) {
143 len +=
144 sprintf(buf + len, "Dedicated for %s ",
145 DMA_gDeviceAttribute[channel->
146 devType].name);
147 } else {
148 len += sprintf(buf + len, "Shared ");
149 }
150
151 if ((channel->flags & DMA_CHANNEL_FLAG_NO_ISR) != 0) {
152 len += sprintf(buf + len, "No ISR ");
153 }
154
155 if ((channel->flags & DMA_CHANNEL_FLAG_LARGE_FIFO) != 0) {
156 len += sprintf(buf + len, "Fifo: 128 ");
157 } else {
158 len += sprintf(buf + len, "Fifo: 64 ");
159 }
160
161 if ((channel->flags & DMA_CHANNEL_FLAG_IN_USE) != 0) {
162 len +=
163 sprintf(buf + len, "InUse by %s",
164 DMA_gDeviceAttribute[channel->
165 devType].name);
166 #if (DMA_DEBUG_TRACK_RESERVATION)
167 len +=
168 sprintf(buf + len, " (%s:%d)",
169 channel->fileName,
170 channel->lineNum);
171 #endif
172 } else {
173 len += sprintf(buf + len, "Avail ");
174 }
175
176 if (channel->lastDevType != DMA_DEVICE_NONE) {
177 len +=
178 sprintf(buf + len, "Last use: %s ",
179 DMA_gDeviceAttribute[channel->
180 lastDevType].
181 name);
182 }
183
184 len += sprintf(buf + len, "\n");
185 }
186 }
187 up(&gDMA.lock);
188 *eof = 1;
189
190 return len;
191 }
192
193 /****************************************************************************/
194 /**
195 * Displays information for /proc/dma/devices
196 */
197 /****************************************************************************/
198
199 static int dma_proc_read_devices(char *buf, char **start, off_t offset,
200 int count, int *eof, void *data)
201 {
202 int limit = count - 200;
203 int len = 0;
204 int devIdx;
205
206 if (down_interruptible(&gDMA.lock) < 0) {
207 return -ERESTARTSYS;
208 }
209
210 for (devIdx = 0; devIdx < DMA_NUM_DEVICE_ENTRIES; devIdx++) {
211 DMA_DeviceAttribute_t *devAttr = &DMA_gDeviceAttribute[devIdx];
212
213 if (devAttr->name == NULL) {
214 continue;
215 }
216
217 if (len >= limit) {
218 break;
219 }
220
221 len += sprintf(buf + len, "%-12s ", devAttr->name);
222
223 if ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) != 0) {
224 len +=
225 sprintf(buf + len, "Dedicated %d:%d ",
226 devAttr->dedicatedController,
227 devAttr->dedicatedChannel);
228 } else {
229 len += sprintf(buf + len, "Shared DMA:");
230 if ((devAttr->flags & DMA_DEVICE_FLAG_ON_DMA0) != 0) {
231 len += sprintf(buf + len, "0");
232 }
233 if ((devAttr->flags & DMA_DEVICE_FLAG_ON_DMA1) != 0) {
234 len += sprintf(buf + len, "1");
235 }
236 len += sprintf(buf + len, " ");
237 }
238 if ((devAttr->flags & DMA_DEVICE_FLAG_NO_ISR) != 0) {
239 len += sprintf(buf + len, "NoISR ");
240 }
241 if ((devAttr->flags & DMA_DEVICE_FLAG_ALLOW_LARGE_FIFO) != 0) {
242 len += sprintf(buf + len, "Allow-128 ");
243 }
244
245 len +=
246 sprintf(buf + len,
247 "Xfer #: %Lu Ticks: %Lu Bytes: %Lu DescLen: %u\n",
248 devAttr->numTransfers, devAttr->transferTicks,
249 devAttr->transferBytes,
250 devAttr->ring.bytesAllocated);
251
252 }
253
254 up(&gDMA.lock);
255 *eof = 1;
256
257 return len;
258 }
259
260 /****************************************************************************/
261 /**
262 * Determines if a DMA_Device_t is "valid".
263 *
264 * @return
265 * TRUE - dma device is valid
266 * FALSE - dma device isn't valid
267 */
268 /****************************************************************************/
269
270 static inline int IsDeviceValid(DMA_Device_t device)
271 {
272 return (device >= 0) && (device < DMA_NUM_DEVICE_ENTRIES);
273 }
274
275 /****************************************************************************/
276 /**
277 * Translates a DMA handle into a pointer to a channel.
278 *
279 * @return
280 * non-NULL - pointer to DMA_Channel_t
281 * NULL - DMA Handle was invalid
282 */
283 /****************************************************************************/
284
285 static inline DMA_Channel_t *HandleToChannel(DMA_Handle_t handle)
286 {
287 int controllerIdx;
288 int channelIdx;
289
290 controllerIdx = CONTROLLER_FROM_HANDLE(handle);
291 channelIdx = CHANNEL_FROM_HANDLE(handle);
292
293 if ((controllerIdx > DMA_NUM_CONTROLLERS)
294 || (channelIdx > DMA_NUM_CHANNELS)) {
295 return NULL;
296 }
297 return &gDMA.controller[controllerIdx].channel[channelIdx];
298 }
299
300 /****************************************************************************/
301 /**
302 * Interrupt handler which is called to process DMA interrupts.
303 */
304 /****************************************************************************/
305
306 static irqreturn_t dma_interrupt_handler(int irq, void *dev_id)
307 {
308 DMA_Channel_t *channel;
309 DMA_DeviceAttribute_t *devAttr;
310 int irqStatus;
311
312 channel = (DMA_Channel_t *) dev_id;
313
314 /* Figure out why we were called, and knock down the interrupt */
315
316 irqStatus = dmacHw_getInterruptStatus(channel->dmacHwHandle);
317 dmacHw_clearInterrupt(channel->dmacHwHandle);
318
319 if ((channel->devType < 0)
320 || (channel->devType > DMA_NUM_DEVICE_ENTRIES)) {
321 printk(KERN_ERR "dma_interrupt_handler: Invalid devType: %d\n",
322 channel->devType);
323 return IRQ_NONE;
324 }
325 devAttr = &DMA_gDeviceAttribute[channel->devType];
326
327 /* Update stats */
328
329 if ((irqStatus & dmacHw_INTERRUPT_STATUS_TRANS) != 0) {
330 devAttr->transferTicks +=
331 (timer_get_tick_count() - devAttr->transferStartTime);
332 }
333
334 if ((irqStatus & dmacHw_INTERRUPT_STATUS_ERROR) != 0) {
335 printk(KERN_ERR
336 "dma_interrupt_handler: devType :%d DMA error (%s)\n",
337 channel->devType, devAttr->name);
338 } else {
339 devAttr->numTransfers++;
340 devAttr->transferBytes += devAttr->numBytes;
341 }
342
343 /* Call any installed handler */
344
345 if (devAttr->devHandler != NULL) {
346 devAttr->devHandler(channel->devType, irqStatus,
347 devAttr->userData);
348 }
349
350 return IRQ_HANDLED;
351 }
352
353 /****************************************************************************/
354 /**
355 * Allocates memory to hold a descriptor ring. The descriptor ring then
356 * needs to be populated by making one or more calls to
357 * dna_add_descriptors.
358 *
359 * The returned descriptor ring will be automatically initialized.
360 *
361 * @return
362 * 0 Descriptor ring was allocated successfully
363 * -EINVAL Invalid parameters passed in
364 * -ENOMEM Unable to allocate memory for the desired number of descriptors.
365 */
366 /****************************************************************************/
367
368 int dma_alloc_descriptor_ring(DMA_DescriptorRing_t *ring, /* Descriptor ring to populate */
369 int numDescriptors /* Number of descriptors that need to be allocated. */
370 ) {
371 size_t bytesToAlloc = dmacHw_descriptorLen(numDescriptors);
372
373 if ((ring == NULL) || (numDescriptors <= 0)) {
374 return -EINVAL;
375 }
376
377 ring->physAddr = 0;
378 ring->descriptorsAllocated = 0;
379 ring->bytesAllocated = 0;
380
381 ring->virtAddr = dma_alloc_writecombine(NULL,
382 bytesToAlloc,
383 &ring->physAddr,
384 GFP_KERNEL);
385 if (ring->virtAddr == NULL) {
386 return -ENOMEM;
387 }
388
389 ring->bytesAllocated = bytesToAlloc;
390 ring->descriptorsAllocated = numDescriptors;
391
392 return dma_init_descriptor_ring(ring, numDescriptors);
393 }
394
395 EXPORT_SYMBOL(dma_alloc_descriptor_ring);
396
397 /****************************************************************************/
398 /**
399 * Releases the memory which was previously allocated for a descriptor ring.
400 */
401 /****************************************************************************/
402
403 void dma_free_descriptor_ring(DMA_DescriptorRing_t *ring /* Descriptor to release */
404 ) {
405 if (ring->virtAddr != NULL) {
406 dma_free_writecombine(NULL,
407 ring->bytesAllocated,
408 ring->virtAddr, ring->physAddr);
409 }
410
411 ring->bytesAllocated = 0;
412 ring->descriptorsAllocated = 0;
413 ring->virtAddr = NULL;
414 ring->physAddr = 0;
415 }
416
417 EXPORT_SYMBOL(dma_free_descriptor_ring);
418
419 /****************************************************************************/
420 /**
421 * Initializes a descriptor ring, so that descriptors can be added to it.
422 * Once a descriptor ring has been allocated, it may be reinitialized for
423 * use with additional/different regions of memory.
424 *
425 * Note that if 7 descriptors are allocated, it's perfectly acceptable to
426 * initialize the ring with a smaller number of descriptors. The amount
427 * of memory allocated for the descriptor ring will not be reduced, and
428 * the descriptor ring may be reinitialized later
429 *
430 * @return
431 * 0 Descriptor ring was initialized successfully
432 * -ENOMEM The descriptor which was passed in has insufficient space
433 * to hold the desired number of descriptors.
434 */
435 /****************************************************************************/
436
437 int dma_init_descriptor_ring(DMA_DescriptorRing_t *ring, /* Descriptor ring to initialize */
438 int numDescriptors /* Number of descriptors to initialize. */
439 ) {
440 if (ring->virtAddr == NULL) {
441 return -EINVAL;
442 }
443 if (dmacHw_initDescriptor(ring->virtAddr,
444 ring->physAddr,
445 ring->bytesAllocated, numDescriptors) < 0) {
446 printk(KERN_ERR
447 "dma_init_descriptor_ring: dmacHw_initDescriptor failed\n");
448 return -ENOMEM;
449 }
450
451 return 0;
452 }
453
454 EXPORT_SYMBOL(dma_init_descriptor_ring);
455
456 /****************************************************************************/
457 /**
458 * Determines the number of descriptors which would be required for a
459 * transfer of the indicated memory region.
460 *
461 * This function also needs to know which DMA device this transfer will
462 * be destined for, so that the appropriate DMA configuration can be retrieved.
463 * DMA parameters such as transfer width, and whether this is a memory-to-memory
464 * or memory-to-peripheral, etc can all affect the actual number of descriptors
465 * required.
466 *
467 * @return
468 * > 0 Returns the number of descriptors required for the indicated transfer
469 * -ENODEV - Device handed in is invalid.
470 * -EINVAL Invalid parameters
471 * -ENOMEM Memory exhausted
472 */
473 /****************************************************************************/
474
475 int dma_calculate_descriptor_count(DMA_Device_t device, /* DMA Device that this will be associated with */
476 dma_addr_t srcData, /* Place to get data to write to device */
477 dma_addr_t dstData, /* Pointer to device data address */
478 size_t numBytes /* Number of bytes to transfer to the device */
479 ) {
480 int numDescriptors;
481 DMA_DeviceAttribute_t *devAttr;
482
483 if (!IsDeviceValid(device)) {
484 return -ENODEV;
485 }
486 devAttr = &DMA_gDeviceAttribute[device];
487
488 numDescriptors = dmacHw_calculateDescriptorCount(&devAttr->config,
489 (void *)srcData,
490 (void *)dstData,
491 numBytes);
492 if (numDescriptors < 0) {
493 printk(KERN_ERR
494 "dma_calculate_descriptor_count: dmacHw_calculateDescriptorCount failed\n");
495 return -EINVAL;
496 }
497
498 return numDescriptors;
499 }
500
501 EXPORT_SYMBOL(dma_calculate_descriptor_count);
502
503 /****************************************************************************/
504 /**
505 * Adds a region of memory to the descriptor ring. Note that it may take
506 * multiple descriptors for each region of memory. It is the callers
507 * responsibility to allocate a sufficiently large descriptor ring.
508 *
509 * @return
510 * 0 Descriptors were added successfully
511 * -ENODEV Device handed in is invalid.
512 * -EINVAL Invalid parameters
513 * -ENOMEM Memory exhausted
514 */
515 /****************************************************************************/
516
517 int dma_add_descriptors(DMA_DescriptorRing_t *ring, /* Descriptor ring to add descriptors to */
518 DMA_Device_t device, /* DMA Device that descriptors are for */
519 dma_addr_t srcData, /* Place to get data (memory or device) */
520 dma_addr_t dstData, /* Place to put data (memory or device) */
521 size_t numBytes /* Number of bytes to transfer to the device */
522 ) {
523 int rc;
524 DMA_DeviceAttribute_t *devAttr;
525
526 if (!IsDeviceValid(device)) {
527 return -ENODEV;
528 }
529 devAttr = &DMA_gDeviceAttribute[device];
530
531 rc = dmacHw_setDataDescriptor(&devAttr->config,
532 ring->virtAddr,
533 (void *)srcData,
534 (void *)dstData, numBytes);
535 if (rc < 0) {
536 printk(KERN_ERR
537 "dma_add_descriptors: dmacHw_setDataDescriptor failed with code: %d\n",
538 rc);
539 return -ENOMEM;
540 }
541
542 return 0;
543 }
544
545 EXPORT_SYMBOL(dma_add_descriptors);
546
547 /****************************************************************************/
548 /**
549 * Sets the descriptor ring associated with a device.
550 *
551 * Once set, the descriptor ring will be associated with the device, even
552 * across channel request/free calls. Passing in a NULL descriptor ring
553 * will release any descriptor ring currently associated with the device.
554 *
555 * Note: If you call dma_transfer, or one of the other dma_alloc_ functions
556 * the descriptor ring may be released and reallocated.
557 *
558 * Note: This function will release the descriptor memory for any current
559 * descriptor ring associated with this device.
560 *
561 * @return
562 * 0 Descriptors were added successfully
563 * -ENODEV Device handed in is invalid.
564 */
565 /****************************************************************************/
566
567 int dma_set_device_descriptor_ring(DMA_Device_t device, /* Device to update the descriptor ring for. */
568 DMA_DescriptorRing_t *ring /* Descriptor ring to add descriptors to */
569 ) {
570 DMA_DeviceAttribute_t *devAttr;
571
572 if (!IsDeviceValid(device)) {
573 return -ENODEV;
574 }
575 devAttr = &DMA_gDeviceAttribute[device];
576
577 /* Free the previously allocated descriptor ring */
578
579 dma_free_descriptor_ring(&devAttr->ring);
580
581 if (ring != NULL) {
582 /* Copy in the new one */
583
584 devAttr->ring = *ring;
585 }
586
587 /* Set things up so that if dma_transfer is called then this descriptor */
588 /* ring will get freed. */
589
590 devAttr->prevSrcData = 0;
591 devAttr->prevDstData = 0;
592 devAttr->prevNumBytes = 0;
593
594 return 0;
595 }
596
597 EXPORT_SYMBOL(dma_set_device_descriptor_ring);
598
599 /****************************************************************************/
600 /**
601 * Retrieves the descriptor ring associated with a device.
602 *
603 * @return
604 * 0 Descriptors were added successfully
605 * -ENODEV Device handed in is invalid.
606 */
607 /****************************************************************************/
608
609 int dma_get_device_descriptor_ring(DMA_Device_t device, /* Device to retrieve the descriptor ring for. */
610 DMA_DescriptorRing_t *ring /* Place to store retrieved ring */
611 ) {
612 DMA_DeviceAttribute_t *devAttr;
613
614 memset(ring, 0, sizeof(*ring));
615
616 if (!IsDeviceValid(device)) {
617 return -ENODEV;
618 }
619 devAttr = &DMA_gDeviceAttribute[device];
620
621 *ring = devAttr->ring;
622
623 return 0;
624 }
625
626 EXPORT_SYMBOL(dma_get_device_descriptor_ring);
627
628 /****************************************************************************/
629 /**
630 * Configures a DMA channel.
631 *
632 * @return
633 * >= 0 - Initialization was successful.
634 *
635 * -EBUSY - Device is currently being used.
636 * -ENODEV - Device handed in is invalid.
637 */
638 /****************************************************************************/
639
640 static int ConfigChannel(DMA_Handle_t handle)
641 {
642 DMA_Channel_t *channel;
643 DMA_DeviceAttribute_t *devAttr;
644 int controllerIdx;
645
646 channel = HandleToChannel(handle);
647 if (channel == NULL) {
648 return -ENODEV;
649 }
650 devAttr = &DMA_gDeviceAttribute[channel->devType];
651 controllerIdx = CONTROLLER_FROM_HANDLE(handle);
652
653 if ((devAttr->flags & DMA_DEVICE_FLAG_PORT_PER_DMAC) != 0) {
654 if (devAttr->config.transferType ==
655 dmacHw_TRANSFER_TYPE_MEM_TO_PERIPHERAL) {
656 devAttr->config.dstPeripheralPort =
657 devAttr->dmacPort[controllerIdx];
658 } else if (devAttr->config.transferType ==
659 dmacHw_TRANSFER_TYPE_PERIPHERAL_TO_MEM) {
660 devAttr->config.srcPeripheralPort =
661 devAttr->dmacPort[controllerIdx];
662 }
663 }
664
665 if (dmacHw_configChannel(channel->dmacHwHandle, &devAttr->config) != 0) {
666 printk(KERN_ERR "ConfigChannel: dmacHw_configChannel failed\n");
667 return -EIO;
668 }
669
670 return 0;
671 }
672
673 /****************************************************************************/
674 /**
675 * Initializes all of the data structures associated with the DMA.
676 * @return
677 * >= 0 - Initialization was successful.
678 *
679 * -EBUSY - Device is currently being used.
680 * -ENODEV - Device handed in is invalid.
681 */
682 /****************************************************************************/
683
684 int dma_init(void)
685 {
686 int rc = 0;
687 int controllerIdx;
688 int channelIdx;
689 DMA_Device_t devIdx;
690 DMA_Channel_t *channel;
691 DMA_Handle_t dedicatedHandle;
692
693 memset(&gDMA, 0, sizeof(gDMA));
694
695 sema_init(&gDMA.lock, 0);
696 init_waitqueue_head(&gDMA.freeChannelQ);
697
698 /* Initialize the Hardware */
699
700 dmacHw_initDma();
701
702 /* Start off by marking all of the DMA channels as shared. */
703
704 for (controllerIdx = 0; controllerIdx < DMA_NUM_CONTROLLERS;
705 controllerIdx++) {
706 for (channelIdx = 0; channelIdx < DMA_NUM_CHANNELS;
707 channelIdx++) {
708 channel =
709 &gDMA.controller[controllerIdx].channel[channelIdx];
710
711 channel->flags = 0;
712 channel->devType = DMA_DEVICE_NONE;
713 channel->lastDevType = DMA_DEVICE_NONE;
714
715 #if (DMA_DEBUG_TRACK_RESERVATION)
716 channel->fileName = "";
717 channel->lineNum = 0;
718 #endif
719
720 channel->dmacHwHandle =
721 dmacHw_getChannelHandle(dmacHw_MAKE_CHANNEL_ID
722 (controllerIdx,
723 channelIdx));
724 dmacHw_initChannel(channel->dmacHwHandle);
725 }
726 }
727
728 /* Record any special attributes that channels may have */
729
730 gDMA.controller[0].channel[0].flags |= DMA_CHANNEL_FLAG_LARGE_FIFO;
731 gDMA.controller[0].channel[1].flags |= DMA_CHANNEL_FLAG_LARGE_FIFO;
732 gDMA.controller[1].channel[0].flags |= DMA_CHANNEL_FLAG_LARGE_FIFO;
733 gDMA.controller[1].channel[1].flags |= DMA_CHANNEL_FLAG_LARGE_FIFO;
734
735 /* Now walk through and record the dedicated channels. */
736
737 for (devIdx = 0; devIdx < DMA_NUM_DEVICE_ENTRIES; devIdx++) {
738 DMA_DeviceAttribute_t *devAttr = &DMA_gDeviceAttribute[devIdx];
739
740 if (((devAttr->flags & DMA_DEVICE_FLAG_NO_ISR) != 0)
741 && ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) == 0)) {
742 printk(KERN_ERR
743 "DMA Device: %s Can only request NO_ISR for dedicated devices\n",
744 devAttr->name);
745 rc = -EINVAL;
746 goto out;
747 }
748
749 if ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) != 0) {
750 /* This is a dedicated device. Mark the channel as being reserved. */
751
752 if (devAttr->dedicatedController >= DMA_NUM_CONTROLLERS) {
753 printk(KERN_ERR
754 "DMA Device: %s DMA Controller %d is out of range\n",
755 devAttr->name,
756 devAttr->dedicatedController);
757 rc = -EINVAL;
758 goto out;
759 }
760
761 if (devAttr->dedicatedChannel >= DMA_NUM_CHANNELS) {
762 printk(KERN_ERR
763 "DMA Device: %s DMA Channel %d is out of range\n",
764 devAttr->name,
765 devAttr->dedicatedChannel);
766 rc = -EINVAL;
767 goto out;
768 }
769
770 dedicatedHandle =
771 MAKE_HANDLE(devAttr->dedicatedController,
772 devAttr->dedicatedChannel);
773 channel = HandleToChannel(dedicatedHandle);
774
775 if ((channel->flags & DMA_CHANNEL_FLAG_IS_DEDICATED) !=
776 0) {
777 printk
778 ("DMA Device: %s attempting to use same DMA Controller:Channel (%d:%d) as %s\n",
779 devAttr->name,
780 devAttr->dedicatedController,
781 devAttr->dedicatedChannel,
782 DMA_gDeviceAttribute[channel->devType].
783 name);
784 rc = -EBUSY;
785 goto out;
786 }
787
788 channel->flags |= DMA_CHANNEL_FLAG_IS_DEDICATED;
789 channel->devType = devIdx;
790
791 if (devAttr->flags & DMA_DEVICE_FLAG_NO_ISR) {
792 channel->flags |= DMA_CHANNEL_FLAG_NO_ISR;
793 }
794
795 /* For dedicated channels, we can go ahead and configure the DMA channel now */
796 /* as well. */
797
798 ConfigChannel(dedicatedHandle);
799 }
800 }
801
802 /* Go through and register the interrupt handlers */
803
804 for (controllerIdx = 0; controllerIdx < DMA_NUM_CONTROLLERS;
805 controllerIdx++) {
806 for (channelIdx = 0; channelIdx < DMA_NUM_CHANNELS;
807 channelIdx++) {
808 channel =
809 &gDMA.controller[controllerIdx].channel[channelIdx];
810
811 if ((channel->flags & DMA_CHANNEL_FLAG_NO_ISR) == 0) {
812 snprintf(channel->name, sizeof(channel->name),
813 "dma %d:%d %s", controllerIdx,
814 channelIdx,
815 channel->devType ==
816 DMA_DEVICE_NONE ? "" :
817 DMA_gDeviceAttribute[channel->devType].
818 name);
819
820 rc =
821 request_irq(IRQ_DMA0C0 +
822 (controllerIdx *
823 DMA_NUM_CHANNELS) +
824 channelIdx,
825 dma_interrupt_handler,
826 IRQF_DISABLED, channel->name,
827 channel);
828 if (rc != 0) {
829 printk(KERN_ERR
830 "request_irq for IRQ_DMA%dC%d failed\n",
831 controllerIdx, channelIdx);
832 }
833 }
834 }
835 }
836
837 /* Create /proc/dma/channels and /proc/dma/devices */
838
839 gDmaDir = proc_mkdir("dma", NULL);
840
841 if (gDmaDir == NULL) {
842 printk(KERN_ERR "Unable to create /proc/dma\n");
843 } else {
844 create_proc_read_entry("channels", 0, gDmaDir,
845 dma_proc_read_channels, NULL);
846 create_proc_read_entry("devices", 0, gDmaDir,
847 dma_proc_read_devices, NULL);
848 create_proc_read_entry("mem-type", 0, gDmaDir,
849 dma_proc_read_mem_type, NULL);
850 }
851
852 out:
853
854 up(&gDMA.lock);
855
856 return rc;
857 }
858
859 /****************************************************************************/
860 /**
861 * Reserves a channel for use with @a dev. If the device is setup to use
862 * a shared channel, then this function will block until a free channel
863 * becomes available.
864 *
865 * @return
866 * >= 0 - A valid DMA Handle.
867 * -EBUSY - Device is currently being used.
868 * -ENODEV - Device handed in is invalid.
869 */
870 /****************************************************************************/
871
872 #if (DMA_DEBUG_TRACK_RESERVATION)
873 DMA_Handle_t dma_request_channel_dbg
874 (DMA_Device_t dev, const char *fileName, int lineNum)
875 #else
876 DMA_Handle_t dma_request_channel(DMA_Device_t dev)
877 #endif
878 {
879 DMA_Handle_t handle;
880 DMA_DeviceAttribute_t *devAttr;
881 DMA_Channel_t *channel;
882 int controllerIdx;
883 int controllerIdx2;
884 int channelIdx;
885
886 if (down_interruptible(&gDMA.lock) < 0) {
887 return -ERESTARTSYS;
888 }
889
890 if ((dev < 0) || (dev >= DMA_NUM_DEVICE_ENTRIES)) {
891 handle = -ENODEV;
892 goto out;
893 }
894 devAttr = &DMA_gDeviceAttribute[dev];
895
896 #if (DMA_DEBUG_TRACK_RESERVATION)
897 {
898 char *s;
899
900 s = strrchr(fileName, '/');
901 if (s != NULL) {
902 fileName = s + 1;
903 }
904 }
905 #endif
906 if ((devAttr->flags & DMA_DEVICE_FLAG_IN_USE) != 0) {
907 /* This device has already been requested and not been freed */
908
909 printk(KERN_ERR "%s: device %s is already requested\n",
910 __func__, devAttr->name);
911 handle = -EBUSY;
912 goto out;
913 }
914
915 if ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) != 0) {
916 /* This device has a dedicated channel. */
917
918 channel =
919 &gDMA.controller[devAttr->dedicatedController].
920 channel[devAttr->dedicatedChannel];
921 if ((channel->flags & DMA_CHANNEL_FLAG_IN_USE) != 0) {
922 handle = -EBUSY;
923 goto out;
924 }
925
926 channel->flags |= DMA_CHANNEL_FLAG_IN_USE;
927 devAttr->flags |= DMA_DEVICE_FLAG_IN_USE;
928
929 #if (DMA_DEBUG_TRACK_RESERVATION)
930 channel->fileName = fileName;
931 channel->lineNum = lineNum;
932 #endif
933 handle =
934 MAKE_HANDLE(devAttr->dedicatedController,
935 devAttr->dedicatedChannel);
936 goto out;
937 }
938
939 /* This device needs to use one of the shared channels. */
940
941 handle = DMA_INVALID_HANDLE;
942 while (handle == DMA_INVALID_HANDLE) {
943 /* Scan through the shared channels and see if one is available */
944
945 for (controllerIdx2 = 0; controllerIdx2 < DMA_NUM_CONTROLLERS;
946 controllerIdx2++) {
947 /* Check to see if we should try on controller 1 first. */
948
949 controllerIdx = controllerIdx2;
950 if ((devAttr->
951 flags & DMA_DEVICE_FLAG_ALLOC_DMA1_FIRST) != 0) {
952 controllerIdx = 1 - controllerIdx;
953 }
954
955 /* See if the device is available on the controller being tested */
956
957 if ((devAttr->
958 flags & (DMA_DEVICE_FLAG_ON_DMA0 << controllerIdx))
959 != 0) {
960 for (channelIdx = 0;
961 channelIdx < DMA_NUM_CHANNELS;
962 channelIdx++) {
963 channel =
964 &gDMA.controller[controllerIdx].
965 channel[channelIdx];
966
967 if (((channel->
968 flags &
969 DMA_CHANNEL_FLAG_IS_DEDICATED) ==
970 0)
971 &&
972 ((channel->
973 flags & DMA_CHANNEL_FLAG_IN_USE)
974 == 0)) {
975 if (((channel->
976 flags &
977 DMA_CHANNEL_FLAG_LARGE_FIFO)
978 != 0)
979 &&
980 ((devAttr->
981 flags &
982 DMA_DEVICE_FLAG_ALLOW_LARGE_FIFO)
983 == 0)) {
984 /* This channel is a large fifo - don't tie it up */
985 /* with devices that we don't want using it. */
986
987 continue;
988 }
989
990 channel->flags |=
991 DMA_CHANNEL_FLAG_IN_USE;
992 channel->devType = dev;
993 devAttr->flags |=
994 DMA_DEVICE_FLAG_IN_USE;
995
996 #if (DMA_DEBUG_TRACK_RESERVATION)
997 channel->fileName = fileName;
998 channel->lineNum = lineNum;
999 #endif
1000 handle =
1001 MAKE_HANDLE(controllerIdx,
1002 channelIdx);
1003
1004 /* Now that we've reserved the channel - we can go ahead and configure it */
1005
1006 if (ConfigChannel(handle) != 0) {
1007 handle = -EIO;
1008 printk(KERN_ERR
1009 "dma_request_channel: ConfigChannel failed\n");
1010 }
1011 goto out;
1012 }
1013 }
1014 }
1015 }
1016
1017 /* No channels are currently available. Let's wait for one to free up. */
1018
1019 {
1020 DEFINE_WAIT(wait);
1021
1022 prepare_to_wait(&gDMA.freeChannelQ, &wait,
1023 TASK_INTERRUPTIBLE);
1024 up(&gDMA.lock);
1025 schedule();
1026 finish_wait(&gDMA.freeChannelQ, &wait);
1027
1028 if (signal_pending(current)) {
1029 /* We don't currently hold gDMA.lock, so we return directly */
1030
1031 return -ERESTARTSYS;
1032 }
1033 }
1034
1035 if (down_interruptible(&gDMA.lock)) {
1036 return -ERESTARTSYS;
1037 }
1038 }
1039
1040 out:
1041 up(&gDMA.lock);
1042
1043 return handle;
1044 }
1045
1046 /* Create both _dbg and non _dbg functions for modules. */
1047
1048 #if (DMA_DEBUG_TRACK_RESERVATION)
1049 #undef dma_request_channel
1050 DMA_Handle_t dma_request_channel(DMA_Device_t dev)
1051 {
1052 return dma_request_channel_dbg(dev, __FILE__, __LINE__);
1053 }
1054
1055 EXPORT_SYMBOL(dma_request_channel_dbg);
1056 #endif
1057 EXPORT_SYMBOL(dma_request_channel);
1058
1059 /****************************************************************************/
1060 /**
1061 * Frees a previously allocated DMA Handle.
1062 */
1063 /****************************************************************************/
1064
1065 int dma_free_channel(DMA_Handle_t handle /* DMA handle. */
1066 ) {
1067 int rc = 0;
1068 DMA_Channel_t *channel;
1069 DMA_DeviceAttribute_t *devAttr;
1070
1071 if (down_interruptible(&gDMA.lock) < 0) {
1072 return -ERESTARTSYS;
1073 }
1074
1075 channel = HandleToChannel(handle);
1076 if (channel == NULL) {
1077 rc = -EINVAL;
1078 goto out;
1079 }
1080
1081 devAttr = &DMA_gDeviceAttribute[channel->devType];
1082
1083 if ((channel->flags & DMA_CHANNEL_FLAG_IS_DEDICATED) == 0) {
1084 channel->lastDevType = channel->devType;
1085 channel->devType = DMA_DEVICE_NONE;
1086 }
1087 channel->flags &= ~DMA_CHANNEL_FLAG_IN_USE;
1088 devAttr->flags &= ~DMA_DEVICE_FLAG_IN_USE;
1089
1090 out:
1091 up(&gDMA.lock);
1092
1093 wake_up_interruptible(&gDMA.freeChannelQ);
1094
1095 return rc;
1096 }
1097
1098 EXPORT_SYMBOL(dma_free_channel);
1099
1100 /****************************************************************************/
1101 /**
1102 * Determines if a given device has been configured as using a shared
1103 * channel.
1104 *
1105 * @return
1106 * 0 Device uses a dedicated channel
1107 * > zero Device uses a shared channel
1108 * < zero Error code
1109 */
1110 /****************************************************************************/
1111
1112 int dma_device_is_channel_shared(DMA_Device_t device /* Device to check. */
1113 ) {
1114 DMA_DeviceAttribute_t *devAttr;
1115
1116 if (!IsDeviceValid(device)) {
1117 return -ENODEV;
1118 }
1119 devAttr = &DMA_gDeviceAttribute[device];
1120
1121 return ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) == 0);
1122 }
1123
1124 EXPORT_SYMBOL(dma_device_is_channel_shared);
1125
1126 /****************************************************************************/
1127 /**
1128 * Allocates buffers for the descriptors. This is normally done automatically
1129 * but needs to be done explicitly when initiating a dma from interrupt
1130 * context.
1131 *
1132 * @return
1133 * 0 Descriptors were allocated successfully
1134 * -EINVAL Invalid device type for this kind of transfer
1135 * (i.e. the device is _MEM_TO_DEV and not _DEV_TO_MEM)
1136 * -ENOMEM Memory exhausted
1137 */
1138 /****************************************************************************/
1139
1140 int dma_alloc_descriptors(DMA_Handle_t handle, /* DMA Handle */
1141 dmacHw_TRANSFER_TYPE_e transferType, /* Type of transfer being performed */
1142 dma_addr_t srcData, /* Place to get data to write to device */
1143 dma_addr_t dstData, /* Pointer to device data address */
1144 size_t numBytes /* Number of bytes to transfer to the device */
1145 ) {
1146 DMA_Channel_t *channel;
1147 DMA_DeviceAttribute_t *devAttr;
1148 int numDescriptors;
1149 size_t ringBytesRequired;
1150 int rc = 0;
1151
1152 channel = HandleToChannel(handle);
1153 if (channel == NULL) {
1154 return -ENODEV;
1155 }
1156
1157 devAttr = &DMA_gDeviceAttribute[channel->devType];
1158
1159 if (devAttr->config.transferType != transferType) {
1160 return -EINVAL;
1161 }
1162
1163 /* Figure out how many descriptors we need. */
1164
1165 /* printk("srcData: 0x%08x dstData: 0x%08x, numBytes: %d\n", */
1166 /* srcData, dstData, numBytes); */
1167
1168 numDescriptors = dmacHw_calculateDescriptorCount(&devAttr->config,
1169 (void *)srcData,
1170 (void *)dstData,
1171 numBytes);
1172 if (numDescriptors < 0) {
1173 printk(KERN_ERR "%s: dmacHw_calculateDescriptorCount failed\n",
1174 __func__);
1175 return -EINVAL;
1176 }
1177
1178 /* Check to see if we can reuse the existing descriptor ring, or if we need to allocate */
1179 /* a new one. */
1180
1181 ringBytesRequired = dmacHw_descriptorLen(numDescriptors);
1182
1183 /* printk("ringBytesRequired: %d\n", ringBytesRequired); */
1184
1185 if (ringBytesRequired > devAttr->ring.bytesAllocated) {
1186 /* Make sure that this code path is never taken from interrupt context. */
1187 /* It's OK for an interrupt to initiate a DMA transfer, but the descriptor */
1188 /* allocation needs to have already been done. */
1189
1190 might_sleep();
1191
1192 /* Free the old descriptor ring and allocate a new one. */
1193
1194 dma_free_descriptor_ring(&devAttr->ring);
1195
1196 /* And allocate a new one. */
1197
1198 rc =
1199 dma_alloc_descriptor_ring(&devAttr->ring,
1200 numDescriptors);
1201 if (rc < 0) {
1202 printk(KERN_ERR
1203 "%s: dma_alloc_descriptor_ring(%d) failed\n",
1204 __func__, numDescriptors);
1205 return rc;
1206 }
1207 /* Setup the descriptor for this transfer */
1208
1209 if (dmacHw_initDescriptor(devAttr->ring.virtAddr,
1210 devAttr->ring.physAddr,
1211 devAttr->ring.bytesAllocated,
1212 numDescriptors) < 0) {
1213 printk(KERN_ERR "%s: dmacHw_initDescriptor failed\n",
1214 __func__);
1215 return -EINVAL;
1216 }
1217 } else {
1218 /* We've already got enough ring buffer allocated. All we need to do is reset */
1219 /* any control information, just in case the previous DMA was stopped. */
1220
1221 dmacHw_resetDescriptorControl(devAttr->ring.virtAddr);
1222 }
1223
1224 /* dma_alloc/free both set the prevSrc/DstData to 0. If they happen to be the same */
1225 /* as last time, then we don't need to call setDataDescriptor again. */
1226
1227 if (dmacHw_setDataDescriptor(&devAttr->config,
1228 devAttr->ring.virtAddr,
1229 (void *)srcData,
1230 (void *)dstData, numBytes) < 0) {
1231 printk(KERN_ERR "%s: dmacHw_setDataDescriptor failed\n",
1232 __func__);
1233 return -EINVAL;
1234 }
1235
1236 /* Remember the critical information for this transfer so that we can eliminate */
1237 /* another call to dma_alloc_descriptors if the caller reuses the same buffers */
1238
1239 devAttr->prevSrcData = srcData;
1240 devAttr->prevDstData = dstData;
1241 devAttr->prevNumBytes = numBytes;
1242
1243 return 0;
1244 }
1245
1246 EXPORT_SYMBOL(dma_alloc_descriptors);
1247
1248 /****************************************************************************/
1249 /**
1250 * Allocates and sets up descriptors for a double buffered circular buffer.
1251 *
1252 * This is primarily intended to be used for things like the ingress samples
1253 * from a microphone.
1254 *
1255 * @return
1256 * > 0 Number of descriptors actually allocated.
1257 * -EINVAL Invalid device type for this kind of transfer
1258 * (i.e. the device is _MEM_TO_DEV and not _DEV_TO_MEM)
1259 * -ENOMEM Memory exhausted
1260 */
1261 /****************************************************************************/
1262
1263 int dma_alloc_double_dst_descriptors(DMA_Handle_t handle, /* DMA Handle */
1264 dma_addr_t srcData, /* Physical address of source data */
1265 dma_addr_t dstData1, /* Physical address of first destination buffer */
1266 dma_addr_t dstData2, /* Physical address of second destination buffer */
1267 size_t numBytes /* Number of bytes in each destination buffer */
1268 ) {
1269 DMA_Channel_t *channel;
1270 DMA_DeviceAttribute_t *devAttr;
1271 int numDst1Descriptors;
1272 int numDst2Descriptors;
1273 int numDescriptors;
1274 size_t ringBytesRequired;
1275 int rc = 0;
1276
1277 channel = HandleToChannel(handle);
1278 if (channel == NULL) {
1279 return -ENODEV;
1280 }
1281
1282 devAttr = &DMA_gDeviceAttribute[channel->devType];
1283
1284 /* Figure out how many descriptors we need. */
1285
1286 /* printk("srcData: 0x%08x dstData: 0x%08x, numBytes: %d\n", */
1287 /* srcData, dstData, numBytes); */
1288
1289 numDst1Descriptors =
1290 dmacHw_calculateDescriptorCount(&devAttr->config, (void *)srcData,
1291 (void *)dstData1, numBytes);
1292 if (numDst1Descriptors < 0) {
1293 return -EINVAL;
1294 }
1295 numDst2Descriptors =
1296 dmacHw_calculateDescriptorCount(&devAttr->config, (void *)srcData,
1297 (void *)dstData2, numBytes);
1298 if (numDst2Descriptors < 0) {
1299 return -EINVAL;
1300 }
1301 numDescriptors = numDst1Descriptors + numDst2Descriptors;
1302 /* printk("numDescriptors: %d\n", numDescriptors); */
1303
1304 /* Check to see if we can reuse the existing descriptor ring, or if we need to allocate */
1305 /* a new one. */
1306
1307 ringBytesRequired = dmacHw_descriptorLen(numDescriptors);
1308
1309 /* printk("ringBytesRequired: %d\n", ringBytesRequired); */
1310
1311 if (ringBytesRequired > devAttr->ring.bytesAllocated) {
1312 /* Make sure that this code path is never taken from interrupt context. */
1313 /* It's OK for an interrupt to initiate a DMA transfer, but the descriptor */
1314 /* allocation needs to have already been done. */
1315
1316 might_sleep();
1317
1318 /* Free the old descriptor ring and allocate a new one. */
1319
1320 dma_free_descriptor_ring(&devAttr->ring);
1321
1322 /* And allocate a new one. */
1323
1324 rc =
1325 dma_alloc_descriptor_ring(&devAttr->ring,
1326 numDescriptors);
1327 if (rc < 0) {
1328 printk(KERN_ERR
1329 "%s: dma_alloc_descriptor_ring(%d) failed\n",
1330 __func__, ringBytesRequired);
1331 return rc;
1332 }
1333 }
1334
1335 /* Setup the descriptor for this transfer. Since this function is used with */
1336 /* CONTINUOUS DMA operations, we need to reinitialize every time, otherwise */
1337 /* setDataDescriptor will keep trying to append onto the end. */
1338
1339 if (dmacHw_initDescriptor(devAttr->ring.virtAddr,
1340 devAttr->ring.physAddr,
1341 devAttr->ring.bytesAllocated,
1342 numDescriptors) < 0) {
1343 printk(KERN_ERR "%s: dmacHw_initDescriptor failed\n", __func__);
1344 return -EINVAL;
1345 }
1346
1347 /* dma_alloc/free both set the prevSrc/DstData to 0. If they happen to be the same */
1348 /* as last time, then we don't need to call setDataDescriptor again. */
1349
1350 if (dmacHw_setDataDescriptor(&devAttr->config,
1351 devAttr->ring.virtAddr,
1352 (void *)srcData,
1353 (void *)dstData1, numBytes) < 0) {
1354 printk(KERN_ERR "%s: dmacHw_setDataDescriptor 1 failed\n",
1355 __func__);
1356 return -EINVAL;
1357 }
1358 if (dmacHw_setDataDescriptor(&devAttr->config,
1359 devAttr->ring.virtAddr,
1360 (void *)srcData,
1361 (void *)dstData2, numBytes) < 0) {
1362 printk(KERN_ERR "%s: dmacHw_setDataDescriptor 2 failed\n",
1363 __func__);
1364 return -EINVAL;
1365 }
1366
1367 /* You should use dma_start_transfer rather than dma_transfer_xxx so we don't */
1368 /* try to make the 'prev' variables right. */
1369
1370 devAttr->prevSrcData = 0;
1371 devAttr->prevDstData = 0;
1372 devAttr->prevNumBytes = 0;
1373
1374 return numDescriptors;
1375 }
1376
1377 EXPORT_SYMBOL(dma_alloc_double_dst_descriptors);
1378
1379 /****************************************************************************/
1380 /**
1381 * Initiates a transfer when the descriptors have already been setup.
1382 *
1383 * This is a special case, and normally, the dma_transfer_xxx functions should
1384 * be used.
1385 *
1386 * @return
1387 * 0 Transfer was started successfully
1388 * -ENODEV Invalid handle
1389 */
1390 /****************************************************************************/
1391
1392 int dma_start_transfer(DMA_Handle_t handle)
1393 {
1394 DMA_Channel_t *channel;
1395 DMA_DeviceAttribute_t *devAttr;
1396
1397 channel = HandleToChannel(handle);
1398 if (channel == NULL) {
1399 return -ENODEV;
1400 }
1401 devAttr = &DMA_gDeviceAttribute[channel->devType];
1402
1403 dmacHw_initiateTransfer(channel->dmacHwHandle, &devAttr->config,
1404 devAttr->ring.virtAddr);
1405
1406 /* Since we got this far, everything went successfully */
1407
1408 return 0;
1409 }
1410
1411 EXPORT_SYMBOL(dma_start_transfer);
1412
1413 /****************************************************************************/
1414 /**
1415 * Stops a previously started DMA transfer.
1416 *
1417 * @return
1418 * 0 Transfer was stopped successfully
1419 * -ENODEV Invalid handle
1420 */
1421 /****************************************************************************/
1422
1423 int dma_stop_transfer(DMA_Handle_t handle)
1424 {
1425 DMA_Channel_t *channel;
1426
1427 channel = HandleToChannel(handle);
1428 if (channel == NULL) {
1429 return -ENODEV;
1430 }
1431
1432 dmacHw_stopTransfer(channel->dmacHwHandle);
1433
1434 return 0;
1435 }
1436
1437 EXPORT_SYMBOL(dma_stop_transfer);
1438
1439 /****************************************************************************/
1440 /**
1441 * Waits for a DMA to complete by polling. This function is only intended
1442 * to be used for testing. Interrupts should be used for most DMA operations.
1443 */
1444 /****************************************************************************/
1445
1446 int dma_wait_transfer_done(DMA_Handle_t handle)
1447 {
1448 DMA_Channel_t *channel;
1449 dmacHw_TRANSFER_STATUS_e status;
1450
1451 channel = HandleToChannel(handle);
1452 if (channel == NULL) {
1453 return -ENODEV;
1454 }
1455
1456 while ((status =
1457 dmacHw_transferCompleted(channel->dmacHwHandle)) ==
1458 dmacHw_TRANSFER_STATUS_BUSY) {
1459 ;
1460 }
1461
1462 if (status == dmacHw_TRANSFER_STATUS_ERROR) {
1463 printk(KERN_ERR "%s: DMA transfer failed\n", __func__);
1464 return -EIO;
1465 }
1466 return 0;
1467 }
1468
1469 EXPORT_SYMBOL(dma_wait_transfer_done);
1470
1471 /****************************************************************************/
1472 /**
1473 * Initiates a DMA, allocating the descriptors as required.
1474 *
1475 * @return
1476 * 0 Transfer was started successfully
1477 * -EINVAL Invalid device type for this kind of transfer
1478 * (i.e. the device is _DEV_TO_MEM and not _MEM_TO_DEV)
1479 */
1480 /****************************************************************************/
1481
1482 int dma_transfer(DMA_Handle_t handle, /* DMA Handle */
1483 dmacHw_TRANSFER_TYPE_e transferType, /* Type of transfer being performed */
1484 dma_addr_t srcData, /* Place to get data to write to device */
1485 dma_addr_t dstData, /* Pointer to device data address */
1486 size_t numBytes /* Number of bytes to transfer to the device */
1487 ) {
1488 DMA_Channel_t *channel;
1489 DMA_DeviceAttribute_t *devAttr;
1490 int rc = 0;
1491
1492 channel = HandleToChannel(handle);
1493 if (channel == NULL) {
1494 return -ENODEV;
1495 }
1496
1497 devAttr = &DMA_gDeviceAttribute[channel->devType];
1498
1499 if (devAttr->config.transferType != transferType) {
1500 return -EINVAL;
1501 }
1502
1503 /* We keep track of the information about the previous request for this */
1504 /* device, and if the attributes match, then we can use the descriptors we setup */
1505 /* the last time, and not have to reinitialize everything. */
1506
1507 {
1508 rc =
1509 dma_alloc_descriptors(handle, transferType, srcData,
1510 dstData, numBytes);
1511 if (rc != 0) {
1512 return rc;
1513 }
1514 }
1515
1516 /* And kick off the transfer */
1517
1518 devAttr->numBytes = numBytes;
1519 devAttr->transferStartTime = timer_get_tick_count();
1520
1521 dmacHw_initiateTransfer(channel->dmacHwHandle, &devAttr->config,
1522 devAttr->ring.virtAddr);
1523
1524 /* Since we got this far, everything went successfully */
1525
1526 return 0;
1527 }
1528
1529 EXPORT_SYMBOL(dma_transfer);
1530
1531 /****************************************************************************/
1532 /**
1533 * Set the callback function which will be called when a transfer completes.
1534 * If a NULL callback function is set, then no callback will occur.
1535 *
1536 * @note @a devHandler will be called from IRQ context.
1537 *
1538 * @return
1539 * 0 - Success
1540 * -ENODEV - Device handed in is invalid.
1541 */
1542 /****************************************************************************/
1543
1544 int dma_set_device_handler(DMA_Device_t dev, /* Device to set the callback for. */
1545 DMA_DeviceHandler_t devHandler, /* Function to call when the DMA completes */
1546 void *userData /* Pointer which will be passed to devHandler. */
1547 ) {
1548 DMA_DeviceAttribute_t *devAttr;
1549 unsigned long flags;
1550
1551 if (!IsDeviceValid(dev)) {
1552 return -ENODEV;
1553 }
1554 devAttr = &DMA_gDeviceAttribute[dev];
1555
1556 local_irq_save(flags);
1557
1558 devAttr->userData = userData;
1559 devAttr->devHandler = devHandler;
1560
1561 local_irq_restore(flags);
1562
1563 return 0;
1564 }
1565
1566 EXPORT_SYMBOL(dma_set_device_handler);
1567
1568 /****************************************************************************/
1569 /**
1570 * Initializes a memory mapping structure
1571 */
1572 /****************************************************************************/
1573
1574 int dma_init_mem_map(DMA_MemMap_t *memMap)
1575 {
1576 memset(memMap, 0, sizeof(*memMap));
1577
1578 sema_init(&memMap->lock, 1);
1579
1580 return 0;
1581 }
1582
1583 EXPORT_SYMBOL(dma_init_mem_map);
1584
1585 /****************************************************************************/
1586 /**
1587 * Releases any memory currently being held by a memory mapping structure.
1588 */
1589 /****************************************************************************/
1590
1591 int dma_term_mem_map(DMA_MemMap_t *memMap)
1592 {
1593 down(&memMap->lock); /* Just being paranoid */
1594
1595 /* Free up any allocated memory */
1596
1597 up(&memMap->lock);
1598 memset(memMap, 0, sizeof(*memMap));
1599
1600 return 0;
1601 }
1602
1603 EXPORT_SYMBOL(dma_term_mem_map);
1604
1605 /****************************************************************************/
1606 /**
1607 * Looks at a memory address and categorizes it.
1608 *
1609 * @return One of the values from the DMA_MemType_t enumeration.
1610 */
1611 /****************************************************************************/
1612
1613 DMA_MemType_t dma_mem_type(void *addr)
1614 {
1615 unsigned long addrVal = (unsigned long)addr;
1616
1617 if (addrVal >= VMALLOC_END) {
1618 /* NOTE: DMA virtual memory space starts at 0xFFxxxxxx */
1619
1620 /* dma_alloc_xxx pages are physically and virtually contiguous */
1621
1622 return DMA_MEM_TYPE_DMA;
1623 }
1624
1625 /* Technically, we could add one more classification. Addresses between VMALLOC_END */
1626 /* and the beginning of the DMA virtual address could be considered to be I/O space. */
1627 /* Right now, nobody cares about this particular classification, so we ignore it. */
1628
1629 if (is_vmalloc_addr(addr)) {
1630 /* Address comes from the vmalloc'd region. Pages are virtually */
1631 /* contiguous but NOT physically contiguous */
1632
1633 return DMA_MEM_TYPE_VMALLOC;
1634 }
1635
1636 if (addrVal >= PAGE_OFFSET) {
1637 /* PAGE_OFFSET is typically 0xC0000000 */
1638
1639 /* kmalloc'd pages are physically contiguous */
1640
1641 return DMA_MEM_TYPE_KMALLOC;
1642 }
1643
1644 return DMA_MEM_TYPE_USER;
1645 }
1646
1647 EXPORT_SYMBOL(dma_mem_type);
1648
1649 /****************************************************************************/
1650 /**
1651 * Looks at a memory address and determines if we support DMA'ing to/from
1652 * that type of memory.
1653 *
1654 * @return boolean -
1655 * return value != 0 means dma supported
1656 * return value == 0 means dma not supported
1657 */
1658 /****************************************************************************/
1659
1660 int dma_mem_supports_dma(void *addr)
1661 {
1662 DMA_MemType_t memType = dma_mem_type(addr);
1663
1664 return (memType == DMA_MEM_TYPE_DMA)
1665 #if ALLOW_MAP_OF_KMALLOC_MEMORY
1666 || (memType == DMA_MEM_TYPE_KMALLOC)
1667 #endif
1668 || (memType == DMA_MEM_TYPE_USER);
1669 }
1670
1671 EXPORT_SYMBOL(dma_mem_supports_dma);
1672
1673 /****************************************************************************/
1674 /**
1675 * Maps in a memory region such that it can be used for performing a DMA.
1676 *
1677 * @return
1678 */
1679 /****************************************************************************/
1680
1681 int dma_map_start(DMA_MemMap_t *memMap, /* Stores state information about the map */
1682 enum dma_data_direction dir /* Direction that the mapping will be going */
1683 ) {
1684 int rc;
1685
1686 down(&memMap->lock);
1687
1688 DMA_MAP_PRINT("memMap: %p\n", memMap);
1689
1690 if (memMap->inUse) {
1691 printk(KERN_ERR "%s: memory map %p is already being used\n",
1692 __func__, memMap);
1693 rc = -EBUSY;
1694 goto out;
1695 }
1696
1697 memMap->inUse = 1;
1698 memMap->dir = dir;
1699 memMap->numRegionsUsed = 0;
1700
1701 rc = 0;
1702
1703 out:
1704
1705 DMA_MAP_PRINT("returning %d", rc);
1706
1707 up(&memMap->lock);
1708
1709 return rc;
1710 }
1711
1712 EXPORT_SYMBOL(dma_map_start);
1713
1714 /****************************************************************************/
1715 /**
1716 * Adds a segment of memory to a memory map. Each segment is both
1717 * physically and virtually contiguous.
1718 *
1719 * @return 0 on success, error code otherwise.
1720 */
1721 /****************************************************************************/
1722
1723 static int dma_map_add_segment(DMA_MemMap_t *memMap, /* Stores state information about the map */
1724 DMA_Region_t *region, /* Region that the segment belongs to */
1725 void *virtAddr, /* Virtual address of the segment being added */
1726 dma_addr_t physAddr, /* Physical address of the segment being added */
1727 size_t numBytes /* Number of bytes of the segment being added */
1728 ) {
1729 DMA_Segment_t *segment;
1730
1731 DMA_MAP_PRINT("memMap:%p va:%p pa:0x%x #:%d\n", memMap, virtAddr,
1732 physAddr, numBytes);
1733
1734 /* Sanity check */
1735
1736 if (((unsigned long)virtAddr < (unsigned long)region->virtAddr)
1737 || (((unsigned long)virtAddr + numBytes)) >
1738 ((unsigned long)region->virtAddr + region->numBytes)) {
1739 printk(KERN_ERR
1740 "%s: virtAddr %p is outside region @ %p len: %d\n",
1741 __func__, virtAddr, region->virtAddr, region->numBytes);
1742 return -EINVAL;
1743 }
1744
1745 if (region->numSegmentsUsed > 0) {
1746 /* Check to see if this segment is physically contiguous with the previous one */
1747
1748 segment = &region->segment[region->numSegmentsUsed - 1];
1749
1750 if ((segment->physAddr + segment->numBytes) == physAddr) {
1751 /* It is - just add on to the end */
1752
1753 DMA_MAP_PRINT("appending %d bytes to last segment\n",
1754 numBytes);
1755
1756 segment->numBytes += numBytes;
1757
1758 return 0;
1759 }
1760 }
1761
1762 /* Reallocate to hold more segments, if required. */
1763
1764 if (region->numSegmentsUsed >= region->numSegmentsAllocated) {
1765 DMA_Segment_t *newSegment;
1766 size_t oldSize =
1767 region->numSegmentsAllocated * sizeof(*newSegment);
1768 int newAlloc = region->numSegmentsAllocated + 4;
1769 size_t newSize = newAlloc * sizeof(*newSegment);
1770
1771 newSegment = kmalloc(newSize, GFP_KERNEL);
1772 if (newSegment == NULL) {
1773 return -ENOMEM;
1774 }
1775 memcpy(newSegment, region->segment, oldSize);
1776 memset(&((uint8_t *) newSegment)[oldSize], 0,
1777 newSize - oldSize);
1778 kfree(region->segment);
1779
1780 region->numSegmentsAllocated = newAlloc;
1781 region->segment = newSegment;
1782 }
1783
1784 segment = &region->segment[region->numSegmentsUsed];
1785 region->numSegmentsUsed++;
1786
1787 segment->virtAddr = virtAddr;
1788 segment->physAddr = physAddr;
1789 segment->numBytes = numBytes;
1790
1791 DMA_MAP_PRINT("returning success\n");
1792
1793 return 0;
1794 }
1795
1796 /****************************************************************************/
1797 /**
1798 * Adds a region of memory to a memory map. Each region is virtually
1799 * contiguous, but not necessarily physically contiguous.
1800 *
1801 * @return 0 on success, error code otherwise.
1802 */
1803 /****************************************************************************/
1804
1805 int dma_map_add_region(DMA_MemMap_t *memMap, /* Stores state information about the map */
1806 void *mem, /* Virtual address that we want to get a map of */
1807 size_t numBytes /* Number of bytes being mapped */
1808 ) {
1809 unsigned long addr = (unsigned long)mem;
1810 unsigned int offset;
1811 int rc = 0;
1812 DMA_Region_t *region;
1813 dma_addr_t physAddr;
1814
1815 down(&memMap->lock);
1816
1817 DMA_MAP_PRINT("memMap:%p va:%p #:%d\n", memMap, mem, numBytes);
1818
1819 if (!memMap->inUse) {
1820 printk(KERN_ERR "%s: Make sure you call dma_map_start first\n",
1821 __func__);
1822 rc = -EINVAL;
1823 goto out;
1824 }
1825
1826 /* Reallocate to hold more regions. */
1827
1828 if (memMap->numRegionsUsed >= memMap->numRegionsAllocated) {
1829 DMA_Region_t *newRegion;
1830 size_t oldSize =
1831 memMap->numRegionsAllocated * sizeof(*newRegion);
1832 int newAlloc = memMap->numRegionsAllocated + 4;
1833 size_t newSize = newAlloc * sizeof(*newRegion);
1834
1835 newRegion = kmalloc(newSize, GFP_KERNEL);
1836 if (newRegion == NULL) {
1837 rc = -ENOMEM;
1838 goto out;
1839 }
1840 memcpy(newRegion, memMap->region, oldSize);
1841 memset(&((uint8_t *) newRegion)[oldSize], 0, newSize - oldSize);
1842
1843 kfree(memMap->region);
1844
1845 memMap->numRegionsAllocated = newAlloc;
1846 memMap->region = newRegion;
1847 }
1848
1849 region = &memMap->region[memMap->numRegionsUsed];
1850 memMap->numRegionsUsed++;
1851
1852 offset = addr & ~PAGE_MASK;
1853
1854 region->memType = dma_mem_type(mem);
1855 region->virtAddr = mem;
1856 region->numBytes = numBytes;
1857 region->numSegmentsUsed = 0;
1858 region->numLockedPages = 0;
1859 region->lockedPages = NULL;
1860
1861 switch (region->memType) {
1862 case DMA_MEM_TYPE_VMALLOC:
1863 {
1864 atomic_inc(&gDmaStatMemTypeVmalloc);
1865
1866 /* printk(KERN_ERR "%s: vmalloc'd pages are not supported\n", __func__); */
1867
1868 /* vmalloc'd pages are not physically contiguous */
1869
1870 rc = -EINVAL;
1871 break;
1872 }
1873
1874 case DMA_MEM_TYPE_KMALLOC:
1875 {
1876 atomic_inc(&gDmaStatMemTypeKmalloc);
1877
1878 /* kmalloc'd pages are physically contiguous, so they'll have exactly */
1879 /* one segment */
1880
1881 #if ALLOW_MAP_OF_KMALLOC_MEMORY
1882 physAddr =
1883 dma_map_single(NULL, mem, numBytes, memMap->dir);
1884 rc = dma_map_add_segment(memMap, region, mem, physAddr,
1885 numBytes);
1886 #else
1887 rc = -EINVAL;
1888 #endif
1889 break;
1890 }
1891
1892 case DMA_MEM_TYPE_DMA:
1893 {
1894 /* dma_alloc_xxx pages are physically contiguous */
1895
1896 atomic_inc(&gDmaStatMemTypeCoherent);
1897
1898 physAddr = (vmalloc_to_pfn(mem) << PAGE_SHIFT) + offset;
1899
1900 dma_sync_single_for_cpu(NULL, physAddr, numBytes,
1901 memMap->dir);
1902 rc = dma_map_add_segment(memMap, region, mem, physAddr,
1903 numBytes);
1904 break;
1905 }
1906
1907 case DMA_MEM_TYPE_USER:
1908 {
1909 size_t firstPageOffset;
1910 size_t firstPageSize;
1911 struct page **pages;
1912 struct task_struct *userTask;
1913
1914 atomic_inc(&gDmaStatMemTypeUser);
1915
1916 #if 1
1917 /* If the pages are user pages, then the dma_mem_map_set_user_task function */
1918 /* must have been previously called. */
1919
1920 if (memMap->userTask == NULL) {
1921 printk(KERN_ERR
1922 "%s: must call dma_mem_map_set_user_task when using user-mode memory\n",
1923 __func__);
1924 return -EINVAL;
1925 }
1926
1927 /* User pages need to be locked. */
1928
1929 firstPageOffset =
1930 (unsigned long)region->virtAddr & (PAGE_SIZE - 1);
1931 firstPageSize = PAGE_SIZE - firstPageOffset;
1932
1933 region->numLockedPages = (firstPageOffset
1934 + region->numBytes +
1935 PAGE_SIZE - 1) / PAGE_SIZE;
1936 pages =
1937 kmalloc(region->numLockedPages *
1938 sizeof(struct page *), GFP_KERNEL);
1939
1940 if (pages == NULL) {
1941 region->numLockedPages = 0;
1942 return -ENOMEM;
1943 }
1944
1945 userTask = memMap->userTask;
1946
1947 down_read(&userTask->mm->mmap_sem);
1948 rc = get_user_pages(userTask, /* task */
1949 userTask->mm, /* mm */
1950 (unsigned long)region->virtAddr, /* start */
1951 region->numLockedPages, /* len */
1952 memMap->dir == DMA_FROM_DEVICE, /* write */
1953 0, /* force */
1954 pages, /* pages (array of pointers to page) */
1955 NULL); /* vmas */
1956 up_read(&userTask->mm->mmap_sem);
1957
1958 if (rc != region->numLockedPages) {
1959 kfree(pages);
1960 region->numLockedPages = 0;
1961
1962 if (rc >= 0) {
1963 rc = -EINVAL;
1964 }
1965 } else {
1966 uint8_t *virtAddr = region->virtAddr;
1967 size_t bytesRemaining;
1968 int pageIdx;
1969
1970 rc = 0; /* Since get_user_pages returns +ve number */
1971
1972 region->lockedPages = pages;
1973
1974 /* We've locked the user pages. Now we need to walk them and figure */
1975 /* out the physical addresses. */
1976
1977 /* The first page may be partial */
1978
1979 dma_map_add_segment(memMap,
1980 region,
1981 virtAddr,
1982 PFN_PHYS(page_to_pfn
1983 (pages[0])) +
1984 firstPageOffset,
1985 firstPageSize);
1986
1987 virtAddr += firstPageSize;
1988 bytesRemaining =
1989 region->numBytes - firstPageSize;
1990
1991 for (pageIdx = 1;
1992 pageIdx < region->numLockedPages;
1993 pageIdx++) {
1994 size_t bytesThisPage =
1995 (bytesRemaining >
1996 PAGE_SIZE ? PAGE_SIZE :
1997 bytesRemaining);
1998
1999 DMA_MAP_PRINT
2000 ("pageIdx:%d pages[pageIdx]=%p pfn=%u phys=%u\n",
2001 pageIdx, pages[pageIdx],
2002 page_to_pfn(pages[pageIdx]),
2003 PFN_PHYS(page_to_pfn
2004 (pages[pageIdx])));
2005
2006 dma_map_add_segment(memMap,
2007 region,
2008 virtAddr,
2009 PFN_PHYS(page_to_pfn
2010 (pages
2011 [pageIdx])),
2012 bytesThisPage);
2013
2014 virtAddr += bytesThisPage;
2015 bytesRemaining -= bytesThisPage;
2016 }
2017 }
2018 #else
2019 printk(KERN_ERR
2020 "%s: User mode pages are not yet supported\n",
2021 __func__);
2022
2023 /* user pages are not physically contiguous */
2024
2025 rc = -EINVAL;
2026 #endif
2027 break;
2028 }
2029
2030 default:
2031 {
2032 printk(KERN_ERR "%s: Unsupported memory type: %d\n",
2033 __func__, region->memType);
2034
2035 rc = -EINVAL;
2036 break;
2037 }
2038 }
2039
2040 if (rc != 0) {
2041 memMap->numRegionsUsed--;
2042 }
2043
2044 out:
2045
2046 DMA_MAP_PRINT("returning %d\n", rc);
2047
2048 up(&memMap->lock);
2049
2050 return rc;
2051 }
2052
2053 EXPORT_SYMBOL(dma_map_add_segment);
2054
2055 /****************************************************************************/
2056 /**
2057 * Maps in a memory region such that it can be used for performing a DMA.
2058 *
2059 * @return 0 on success, error code otherwise.
2060 */
2061 /****************************************************************************/
2062
2063 int dma_map_mem(DMA_MemMap_t *memMap, /* Stores state information about the map */
2064 void *mem, /* Virtual address that we want to get a map of */
2065 size_t numBytes, /* Number of bytes being mapped */
2066 enum dma_data_direction dir /* Direction that the mapping will be going */
2067 ) {
2068 int rc;
2069
2070 rc = dma_map_start(memMap, dir);
2071 if (rc == 0) {
2072 rc = dma_map_add_region(memMap, mem, numBytes);
2073 if (rc < 0) {
2074 /* Since the add fails, this function will fail, and the caller won't */
2075 /* call unmap, so we need to do it here. */
2076
2077 dma_unmap(memMap, 0);
2078 }
2079 }
2080
2081 return rc;
2082 }
2083
2084 EXPORT_SYMBOL(dma_map_mem);
2085
2086 /****************************************************************************/
2087 /**
2088 * Setup a descriptor ring for a given memory map.
2089 *
2090 * It is assumed that the descriptor ring has already been initialized, and
2091 * this routine will only reallocate a new descriptor ring if the existing
2092 * one is too small.
2093 *
2094 * @return 0 on success, error code otherwise.
2095 */
2096 /****************************************************************************/
2097
2098 int dma_map_create_descriptor_ring(DMA_Device_t dev, /* DMA device (where the ring is stored) */
2099 DMA_MemMap_t *memMap, /* Memory map that will be used */
2100 dma_addr_t devPhysAddr /* Physical address of device */
2101 ) {
2102 int rc;
2103 int numDescriptors;
2104 DMA_DeviceAttribute_t *devAttr;
2105 DMA_Region_t *region;
2106 DMA_Segment_t *segment;
2107 dma_addr_t srcPhysAddr;
2108 dma_addr_t dstPhysAddr;
2109 int regionIdx;
2110 int segmentIdx;
2111
2112 devAttr = &DMA_gDeviceAttribute[dev];
2113
2114 down(&memMap->lock);
2115
2116 /* Figure out how many descriptors we need */
2117
2118 numDescriptors = 0;
2119 for (regionIdx = 0; regionIdx < memMap->numRegionsUsed; regionIdx++) {
2120 region = &memMap->region[regionIdx];
2121
2122 for (segmentIdx = 0; segmentIdx < region->numSegmentsUsed;
2123 segmentIdx++) {
2124 segment = &region->segment[segmentIdx];
2125
2126 if (memMap->dir == DMA_TO_DEVICE) {
2127 srcPhysAddr = segment->physAddr;
2128 dstPhysAddr = devPhysAddr;
2129 } else {
2130 srcPhysAddr = devPhysAddr;
2131 dstPhysAddr = segment->physAddr;
2132 }
2133
2134 rc =
2135 dma_calculate_descriptor_count(dev, srcPhysAddr,
2136 dstPhysAddr,
2137 segment->
2138 numBytes);
2139 if (rc < 0) {
2140 printk(KERN_ERR
2141 "%s: dma_calculate_descriptor_count failed: %d\n",
2142 __func__, rc);
2143 goto out;
2144 }
2145 numDescriptors += rc;
2146 }
2147 }
2148
2149 /* Adjust the size of the ring, if it isn't big enough */
2150
2151 if (numDescriptors > devAttr->ring.descriptorsAllocated) {
2152 dma_free_descriptor_ring(&devAttr->ring);
2153 rc =
2154 dma_alloc_descriptor_ring(&devAttr->ring,
2155 numDescriptors);
2156 if (rc < 0) {
2157 printk(KERN_ERR
2158 "%s: dma_alloc_descriptor_ring failed: %d\n",
2159 __func__, rc);
2160 goto out;
2161 }
2162 } else {
2163 rc =
2164 dma_init_descriptor_ring(&devAttr->ring,
2165 numDescriptors);
2166 if (rc < 0) {
2167 printk(KERN_ERR
2168 "%s: dma_init_descriptor_ring failed: %d\n",
2169 __func__, rc);
2170 goto out;
2171 }
2172 }
2173
2174 /* Populate the descriptors */
2175
2176 for (regionIdx = 0; regionIdx < memMap->numRegionsUsed; regionIdx++) {
2177 region = &memMap->region[regionIdx];
2178
2179 for (segmentIdx = 0; segmentIdx < region->numSegmentsUsed;
2180 segmentIdx++) {
2181 segment = &region->segment[segmentIdx];
2182
2183 if (memMap->dir == DMA_TO_DEVICE) {
2184 srcPhysAddr = segment->physAddr;
2185 dstPhysAddr = devPhysAddr;
2186 } else {
2187 srcPhysAddr = devPhysAddr;
2188 dstPhysAddr = segment->physAddr;
2189 }
2190
2191 rc =
2192 dma_add_descriptors(&devAttr->ring, dev,
2193 srcPhysAddr, dstPhysAddr,
2194 segment->numBytes);
2195 if (rc < 0) {
2196 printk(KERN_ERR
2197 "%s: dma_add_descriptors failed: %d\n",
2198 __func__, rc);
2199 goto out;
2200 }
2201 }
2202 }
2203
2204 rc = 0;
2205
2206 out:
2207
2208 up(&memMap->lock);
2209 return rc;
2210 }
2211
2212 EXPORT_SYMBOL(dma_map_create_descriptor_ring);
2213
2214 /****************************************************************************/
2215 /**
2216 * Maps in a memory region such that it can be used for performing a DMA.
2217 *
2218 * @return
2219 */
2220 /****************************************************************************/
2221
2222 int dma_unmap(DMA_MemMap_t *memMap, /* Stores state information about the map */
2223 int dirtied /* non-zero if any of the pages were modified */
2224 ) {
2225
2226 int rc = 0;
2227 int regionIdx;
2228 int segmentIdx;
2229 DMA_Region_t *region;
2230 DMA_Segment_t *segment;
2231
2232 down(&memMap->lock);
2233
2234 for (regionIdx = 0; regionIdx < memMap->numRegionsUsed; regionIdx++) {
2235 region = &memMap->region[regionIdx];
2236
2237 for (segmentIdx = 0; segmentIdx < region->numSegmentsUsed;
2238 segmentIdx++) {
2239 segment = &region->segment[segmentIdx];
2240
2241 switch (region->memType) {
2242 case DMA_MEM_TYPE_VMALLOC:
2243 {
2244 printk(KERN_ERR
2245 "%s: vmalloc'd pages are not yet supported\n",
2246 __func__);
2247 rc = -EINVAL;
2248 goto out;
2249 }
2250
2251 case DMA_MEM_TYPE_KMALLOC:
2252 {
2253 #if ALLOW_MAP_OF_KMALLOC_MEMORY
2254 dma_unmap_single(NULL,
2255 segment->physAddr,
2256 segment->numBytes,
2257 memMap->dir);
2258 #endif
2259 break;
2260 }
2261
2262 case DMA_MEM_TYPE_DMA:
2263 {
2264 dma_sync_single_for_cpu(NULL,
2265 segment->
2266 physAddr,
2267 segment->
2268 numBytes,
2269 memMap->dir);
2270 break;
2271 }
2272
2273 case DMA_MEM_TYPE_USER:
2274 {
2275 /* Nothing to do here. */
2276
2277 break;
2278 }
2279
2280 default:
2281 {
2282 printk(KERN_ERR
2283 "%s: Unsupported memory type: %d\n",
2284 __func__, region->memType);
2285 rc = -EINVAL;
2286 goto out;
2287 }
2288 }
2289
2290 segment->virtAddr = NULL;
2291 segment->physAddr = 0;
2292 segment->numBytes = 0;
2293 }
2294
2295 if (region->numLockedPages > 0) {
2296 int pageIdx;
2297
2298 /* Some user pages were locked. We need to go and unlock them now. */
2299
2300 for (pageIdx = 0; pageIdx < region->numLockedPages;
2301 pageIdx++) {
2302 struct page *page =
2303 region->lockedPages[pageIdx];
2304
2305 if (memMap->dir == DMA_FROM_DEVICE) {
2306 SetPageDirty(page);
2307 }
2308 page_cache_release(page);
2309 }
2310 kfree(region->lockedPages);
2311 region->numLockedPages = 0;
2312 region->lockedPages = NULL;
2313 }
2314
2315 region->memType = DMA_MEM_TYPE_NONE;
2316 region->virtAddr = NULL;
2317 region->numBytes = 0;
2318 region->numSegmentsUsed = 0;
2319 }
2320 memMap->userTask = NULL;
2321 memMap->numRegionsUsed = 0;
2322 memMap->inUse = 0;
2323
2324 out:
2325 up(&memMap->lock);
2326
2327 return rc;
2328 }
2329
2330 EXPORT_SYMBOL(dma_unmap);
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