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[zen-stable.git] / arch / arm / mach-bcmring / dma.c
blob1a1a27dd56544d0684bebc29d40b69bdff2d190f
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 <linux/sched.h>
40 #include <mach/dma.h>
41
42 /* I don't quite understand why dc4 fails when this is set to 1 and DMA is enabled */
43 /* especially since dc4 doesn't use kmalloc'd memory. */
44
45 #define ALLOW_MAP_OF_KMALLOC_MEMORY 0
46
47 /* ---- Public Variables ------------------------------------------------- */
48
49 /* ---- Private Constants and Types -------------------------------------- */
50
51 #define MAKE_HANDLE(controllerIdx, channelIdx) (((controllerIdx) << 4) | (channelIdx))
52
53 #define CONTROLLER_FROM_HANDLE(handle) (((handle) >> 4) & 0x0f)
54 #define CHANNEL_FROM_HANDLE(handle) ((handle) & 0x0f)
55
56 #define DMA_MAP_DEBUG 0
57
58 #if DMA_MAP_DEBUG
59 # define DMA_MAP_PRINT(fmt, args...) printk("%s: " fmt, __func__, ## args)
60 #else
61 # define DMA_MAP_PRINT(fmt, args...)
62 #endif
63
64 /* ---- Private Variables ------------------------------------------------ */
65
66 static DMA_Global_t gDMA;
67 static struct proc_dir_entry *gDmaDir;
68
69 static atomic_t gDmaStatMemTypeKmalloc = ATOMIC_INIT(0);
70 static atomic_t gDmaStatMemTypeVmalloc = ATOMIC_INIT(0);
71 static atomic_t gDmaStatMemTypeUser = ATOMIC_INIT(0);
72 static atomic_t gDmaStatMemTypeCoherent = ATOMIC_INIT(0);
73
74 #include "dma_device.c"
75
76 /* ---- Private Function Prototypes -------------------------------------- */
77
78 /* ---- Functions ------------------------------------------------------- */
79
80 /****************************************************************************/
81 /**
82 * Displays information for /proc/dma/mem-type
83 */
84 /****************************************************************************/
85
86 static int dma_proc_read_mem_type(char *buf, char **start, off_t offset,
87 int count, int *eof, void *data)
88 {
89 int len = 0;
90
91 len += sprintf(buf + len, "dma_map_mem statistics\n");
92 len +=
93 sprintf(buf + len, "coherent: %d\n",
94 atomic_read(&gDmaStatMemTypeCoherent));
95 len +=
96 sprintf(buf + len, "kmalloc: %d\n",
97 atomic_read(&gDmaStatMemTypeKmalloc));
98 len +=
99 sprintf(buf + len, "vmalloc: %d\n",
100 atomic_read(&gDmaStatMemTypeVmalloc));
101 len +=
102 sprintf(buf + len, "user: %d\n",
103 atomic_read(&gDmaStatMemTypeUser));
104
105 return len;
106 }
107
108 /****************************************************************************/
109 /**
110 * Displays information for /proc/dma/channels
111 */
112 /****************************************************************************/
113
114 static int dma_proc_read_channels(char *buf, char **start, off_t offset,
115 int count, int *eof, void *data)
116 {
117 int controllerIdx;
118 int channelIdx;
119 int limit = count - 200;
120 int len = 0;
121 DMA_Channel_t *channel;
122
123 if (down_interruptible(&gDMA.lock) < 0) {
124 return -ERESTARTSYS;
125 }
126
127 for (controllerIdx = 0; controllerIdx < DMA_NUM_CONTROLLERS;
128 controllerIdx++) {
129 for (channelIdx = 0; channelIdx < DMA_NUM_CHANNELS;
130 channelIdx++) {
131 if (len >= limit) {
132 break;
133 }
134
135 channel =
136 &gDMA.controller[controllerIdx].channel[channelIdx];
137
138 len +=
139 sprintf(buf + len, "%d:%d ", controllerIdx,
140 channelIdx);
141
142 if ((channel->flags & DMA_CHANNEL_FLAG_IS_DEDICATED) !=
143 0) {
144 len +=
145 sprintf(buf + len, "Dedicated for %s ",
146 DMA_gDeviceAttribute[channel->
147 devType].name);
148 } else {
149 len += sprintf(buf + len, "Shared ");
150 }
151
152 if ((channel->flags & DMA_CHANNEL_FLAG_NO_ISR) != 0) {
153 len += sprintf(buf + len, "No ISR ");
154 }
155
156 if ((channel->flags & DMA_CHANNEL_FLAG_LARGE_FIFO) != 0) {
157 len += sprintf(buf + len, "Fifo: 128 ");
158 } else {
159 len += sprintf(buf + len, "Fifo: 64 ");
160 }
161
162 if ((channel->flags & DMA_CHANNEL_FLAG_IN_USE) != 0) {
163 len +=
164 sprintf(buf + len, "InUse by %s",
165 DMA_gDeviceAttribute[channel->
166 devType].name);
167 #if (DMA_DEBUG_TRACK_RESERVATION)
168 len +=
169 sprintf(buf + len, " (%s:%d)",
170 channel->fileName,
171 channel->lineNum);
172 #endif
173 } else {
174 len += sprintf(buf + len, "Avail ");
175 }
176
177 if (channel->lastDevType != DMA_DEVICE_NONE) {
178 len +=
179 sprintf(buf + len, "Last use: %s ",
180 DMA_gDeviceAttribute[channel->
181 lastDevType].
182 name);
183 }
184
185 len += sprintf(buf + len, "\n");
186 }
187 }
188 up(&gDMA.lock);
189 *eof = 1;
190
191 return len;
192 }
193
194 /****************************************************************************/
195 /**
196 * Displays information for /proc/dma/devices
197 */
198 /****************************************************************************/
199
200 static int dma_proc_read_devices(char *buf, char **start, off_t offset,
201 int count, int *eof, void *data)
202 {
203 int limit = count - 200;
204 int len = 0;
205 int devIdx;
206
207 if (down_interruptible(&gDMA.lock) < 0) {
208 return -ERESTARTSYS;
209 }
210
211 for (devIdx = 0; devIdx < DMA_NUM_DEVICE_ENTRIES; devIdx++) {
212 DMA_DeviceAttribute_t *devAttr = &DMA_gDeviceAttribute[devIdx];
213
214 if (devAttr->name == NULL) {
215 continue;
216 }
217
218 if (len >= limit) {
219 break;
220 }
221
222 len += sprintf(buf + len, "%-12s ", devAttr->name);
223
224 if ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) != 0) {
225 len +=
226 sprintf(buf + len, "Dedicated %d:%d ",
227 devAttr->dedicatedController,
228 devAttr->dedicatedChannel);
229 } else {
230 len += sprintf(buf + len, "Shared DMA:");
231 if ((devAttr->flags & DMA_DEVICE_FLAG_ON_DMA0) != 0) {
232 len += sprintf(buf + len, "0");
233 }
234 if ((devAttr->flags & DMA_DEVICE_FLAG_ON_DMA1) != 0) {
235 len += sprintf(buf + len, "1");
236 }
237 len += sprintf(buf + len, " ");
238 }
239 if ((devAttr->flags & DMA_DEVICE_FLAG_NO_ISR) != 0) {
240 len += sprintf(buf + len, "NoISR ");
241 }
242 if ((devAttr->flags & DMA_DEVICE_FLAG_ALLOW_LARGE_FIFO) != 0) {
243 len += sprintf(buf + len, "Allow-128 ");
244 }
245
246 len +=
247 sprintf(buf + len,
248 "Xfer #: %Lu Ticks: %Lu Bytes: %Lu DescLen: %u\n",
249 devAttr->numTransfers, devAttr->transferTicks,
250 devAttr->transferBytes,
251 devAttr->ring.bytesAllocated);
252
253 }
254
255 up(&gDMA.lock);
256 *eof = 1;
257
258 return len;
259 }
260
261 /****************************************************************************/
262 /**
263 * Determines if a DMA_Device_t is "valid".
264 *
265 * @return
266 * TRUE - dma device is valid
267 * FALSE - dma device isn't valid
268 */
269 /****************************************************************************/
270
271 static inline int IsDeviceValid(DMA_Device_t device)
272 {
273 return (device >= 0) && (device < DMA_NUM_DEVICE_ENTRIES);
274 }
275
276 /****************************************************************************/
277 /**
278 * Translates a DMA handle into a pointer to a channel.
279 *
280 * @return
281 * non-NULL - pointer to DMA_Channel_t
282 * NULL - DMA Handle was invalid
283 */
284 /****************************************************************************/
285
286 static inline DMA_Channel_t *HandleToChannel(DMA_Handle_t handle)
287 {
288 int controllerIdx;
289 int channelIdx;
290
291 controllerIdx = CONTROLLER_FROM_HANDLE(handle);
292 channelIdx = CHANNEL_FROM_HANDLE(handle);
293
294 if ((controllerIdx > DMA_NUM_CONTROLLERS)
295 || (channelIdx > DMA_NUM_CHANNELS)) {
296 return NULL;
297 }
298 return &gDMA.controller[controllerIdx].channel[channelIdx];
299 }
300
301 /****************************************************************************/
302 /**
303 * Interrupt handler which is called to process DMA interrupts.
304 */
305 /****************************************************************************/
306
307 static irqreturn_t dma_interrupt_handler(int irq, void *dev_id)
308 {
309 DMA_Channel_t *channel;
310 DMA_DeviceAttribute_t *devAttr;
311 int irqStatus;
312
313 channel = (DMA_Channel_t *) dev_id;
314
315 /* Figure out why we were called, and knock down the interrupt */
316
317 irqStatus = dmacHw_getInterruptStatus(channel->dmacHwHandle);
318 dmacHw_clearInterrupt(channel->dmacHwHandle);
319
320 if ((channel->devType < 0)
321 || (channel->devType > DMA_NUM_DEVICE_ENTRIES)) {
322 printk(KERN_ERR "dma_interrupt_handler: Invalid devType: %d\n",
323 channel->devType);
324 return IRQ_NONE;
325 }
326 devAttr = &DMA_gDeviceAttribute[channel->devType];
327
328 /* Update stats */
329
330 if ((irqStatus & dmacHw_INTERRUPT_STATUS_TRANS) != 0) {
331 devAttr->transferTicks +=
332 (timer_get_tick_count() - devAttr->transferStartTime);
333 }
334
335 if ((irqStatus & dmacHw_INTERRUPT_STATUS_ERROR) != 0) {
336 printk(KERN_ERR
337 "dma_interrupt_handler: devType :%d DMA error (%s)\n",
338 channel->devType, devAttr->name);
339 } else {
340 devAttr->numTransfers++;
341 devAttr->transferBytes += devAttr->numBytes;
342 }
343
344 /* Call any installed handler */
345
346 if (devAttr->devHandler != NULL) {
347 devAttr->devHandler(channel->devType, irqStatus,
348 devAttr->userData);
349 }
350
351 return IRQ_HANDLED;
352 }
353
354 /****************************************************************************/
355 /**
356 * Allocates memory to hold a descriptor ring. The descriptor ring then
357 * needs to be populated by making one or more calls to
358 * dna_add_descriptors.
359 *
360 * The returned descriptor ring will be automatically initialized.
361 *
362 * @return
363 * 0 Descriptor ring was allocated successfully
364 * -EINVAL Invalid parameters passed in
365 * -ENOMEM Unable to allocate memory for the desired number of descriptors.
366 */
367 /****************************************************************************/
368
369 int dma_alloc_descriptor_ring(DMA_DescriptorRing_t *ring, /* Descriptor ring to populate */
370 int numDescriptors /* Number of descriptors that need to be allocated. */
371 ) {
372 size_t bytesToAlloc = dmacHw_descriptorLen(numDescriptors);
373
374 if ((ring == NULL) || (numDescriptors <= 0)) {
375 return -EINVAL;
376 }
377
378 ring->physAddr = 0;
379 ring->descriptorsAllocated = 0;
380 ring->bytesAllocated = 0;
381
382 ring->virtAddr = dma_alloc_writecombine(NULL,
383 bytesToAlloc,
384 &ring->physAddr,
385 GFP_KERNEL);
386 if (ring->virtAddr == NULL) {
387 return -ENOMEM;
388 }
389
390 ring->bytesAllocated = bytesToAlloc;
391 ring->descriptorsAllocated = numDescriptors;
392
393 return dma_init_descriptor_ring(ring, numDescriptors);
394 }
395
396 EXPORT_SYMBOL(dma_alloc_descriptor_ring);
397
398 /****************************************************************************/
399 /**
400 * Releases the memory which was previously allocated for a descriptor ring.
401 */
402 /****************************************************************************/
403
404 void dma_free_descriptor_ring(DMA_DescriptorRing_t *ring /* Descriptor to release */
405 ) {
406 if (ring->virtAddr != NULL) {
407 dma_free_writecombine(NULL,
408 ring->bytesAllocated,
409 ring->virtAddr, ring->physAddr);
410 }
411
412 ring->bytesAllocated = 0;
413 ring->descriptorsAllocated = 0;
414 ring->virtAddr = NULL;
415 ring->physAddr = 0;
416 }
417
418 EXPORT_SYMBOL(dma_free_descriptor_ring);
419
420 /****************************************************************************/
421 /**
422 * Initializes a descriptor ring, so that descriptors can be added to it.
423 * Once a descriptor ring has been allocated, it may be reinitialized for
424 * use with additional/different regions of memory.
425 *
426 * Note that if 7 descriptors are allocated, it's perfectly acceptable to
427 * initialize the ring with a smaller number of descriptors. The amount
428 * of memory allocated for the descriptor ring will not be reduced, and
429 * the descriptor ring may be reinitialized later
430 *
431 * @return
432 * 0 Descriptor ring was initialized successfully
433 * -ENOMEM The descriptor which was passed in has insufficient space
434 * to hold the desired number of descriptors.
435 */
436 /****************************************************************************/
437
438 int dma_init_descriptor_ring(DMA_DescriptorRing_t *ring, /* Descriptor ring to initialize */
439 int numDescriptors /* Number of descriptors to initialize. */
440 ) {
441 if (ring->virtAddr == NULL) {
442 return -EINVAL;
443 }
444 if (dmacHw_initDescriptor(ring->virtAddr,
445 ring->physAddr,
446 ring->bytesAllocated, numDescriptors) < 0) {
447 printk(KERN_ERR
448 "dma_init_descriptor_ring: dmacHw_initDescriptor failed\n");
449 return -ENOMEM;
450 }
451
452 return 0;
453 }
454
455 EXPORT_SYMBOL(dma_init_descriptor_ring);
456
457 /****************************************************************************/
458 /**
459 * Determines the number of descriptors which would be required for a
460 * transfer of the indicated memory region.
461 *
462 * This function also needs to know which DMA device this transfer will
463 * be destined for, so that the appropriate DMA configuration can be retrieved.
464 * DMA parameters such as transfer width, and whether this is a memory-to-memory
465 * or memory-to-peripheral, etc can all affect the actual number of descriptors
466 * required.
467 *
468 * @return
469 * > 0 Returns the number of descriptors required for the indicated transfer
470 * -ENODEV - Device handed in is invalid.
471 * -EINVAL Invalid parameters
472 * -ENOMEM Memory exhausted
473 */
474 /****************************************************************************/
475
476 int dma_calculate_descriptor_count(DMA_Device_t device, /* DMA Device that this will be associated with */
477 dma_addr_t srcData, /* Place to get data to write to device */
478 dma_addr_t dstData, /* Pointer to device data address */
479 size_t numBytes /* Number of bytes to transfer to the device */
480 ) {
481 int numDescriptors;
482 DMA_DeviceAttribute_t *devAttr;
483
484 if (!IsDeviceValid(device)) {
485 return -ENODEV;
486 }
487 devAttr = &DMA_gDeviceAttribute[device];
488
489 numDescriptors = dmacHw_calculateDescriptorCount(&devAttr->config,
490 (void *)srcData,
491 (void *)dstData,
492 numBytes);
493 if (numDescriptors < 0) {
494 printk(KERN_ERR
495 "dma_calculate_descriptor_count: dmacHw_calculateDescriptorCount failed\n");
496 return -EINVAL;
497 }
498
499 return numDescriptors;
500 }
501
502 EXPORT_SYMBOL(dma_calculate_descriptor_count);
503
504 /****************************************************************************/
505 /**
506 * Adds a region of memory to the descriptor ring. Note that it may take
507 * multiple descriptors for each region of memory. It is the callers
508 * responsibility to allocate a sufficiently large descriptor ring.
509 *
510 * @return
511 * 0 Descriptors were added successfully
512 * -ENODEV Device handed in is invalid.
513 * -EINVAL Invalid parameters
514 * -ENOMEM Memory exhausted
515 */
516 /****************************************************************************/
517
518 int dma_add_descriptors(DMA_DescriptorRing_t *ring, /* Descriptor ring to add descriptors to */
519 DMA_Device_t device, /* DMA Device that descriptors are for */
520 dma_addr_t srcData, /* Place to get data (memory or device) */
521 dma_addr_t dstData, /* Place to put data (memory or device) */
522 size_t numBytes /* Number of bytes to transfer to the device */
523 ) {
524 int rc;
525 DMA_DeviceAttribute_t *devAttr;
526
527 if (!IsDeviceValid(device)) {
528 return -ENODEV;
529 }
530 devAttr = &DMA_gDeviceAttribute[device];
531
532 rc = dmacHw_setDataDescriptor(&devAttr->config,
533 ring->virtAddr,
534 (void *)srcData,
535 (void *)dstData, numBytes);
536 if (rc < 0) {
537 printk(KERN_ERR
538 "dma_add_descriptors: dmacHw_setDataDescriptor failed with code: %d\n",
539 rc);
540 return -ENOMEM;
541 }
542
543 return 0;
544 }
545
546 EXPORT_SYMBOL(dma_add_descriptors);
547
548 /****************************************************************************/
549 /**
550 * Sets the descriptor ring associated with a device.
551 *
552 * Once set, the descriptor ring will be associated with the device, even
553 * across channel request/free calls. Passing in a NULL descriptor ring
554 * will release any descriptor ring currently associated with the device.
555 *
556 * Note: If you call dma_transfer, or one of the other dma_alloc_ functions
557 * the descriptor ring may be released and reallocated.
558 *
559 * Note: This function will release the descriptor memory for any current
560 * descriptor ring associated with this device.
561 *
562 * @return
563 * 0 Descriptors were added successfully
564 * -ENODEV Device handed in is invalid.
565 */
566 /****************************************************************************/
567
568 int dma_set_device_descriptor_ring(DMA_Device_t device, /* Device to update the descriptor ring for. */
569 DMA_DescriptorRing_t *ring /* Descriptor ring to add descriptors to */
570 ) {
571 DMA_DeviceAttribute_t *devAttr;
572
573 if (!IsDeviceValid(device)) {
574 return -ENODEV;
575 }
576 devAttr = &DMA_gDeviceAttribute[device];
577
578 /* Free the previously allocated descriptor ring */
579
580 dma_free_descriptor_ring(&devAttr->ring);
581
582 if (ring != NULL) {
583 /* Copy in the new one */
584
585 devAttr->ring = *ring;
586 }
587
588 /* Set things up so that if dma_transfer is called then this descriptor */
589 /* ring will get freed. */
590
591 devAttr->prevSrcData = 0;
592 devAttr->prevDstData = 0;
593 devAttr->prevNumBytes = 0;
594
595 return 0;
596 }
597
598 EXPORT_SYMBOL(dma_set_device_descriptor_ring);
599
600 /****************************************************************************/
601 /**
602 * Retrieves the descriptor ring associated with a device.
603 *
604 * @return
605 * 0 Descriptors were added successfully
606 * -ENODEV Device handed in is invalid.
607 */
608 /****************************************************************************/
609
610 int dma_get_device_descriptor_ring(DMA_Device_t device, /* Device to retrieve the descriptor ring for. */
611 DMA_DescriptorRing_t *ring /* Place to store retrieved ring */
612 ) {
613 DMA_DeviceAttribute_t *devAttr;
614
615 memset(ring, 0, sizeof(*ring));
616
617 if (!IsDeviceValid(device)) {
618 return -ENODEV;
619 }
620 devAttr = &DMA_gDeviceAttribute[device];
621
622 *ring = devAttr->ring;
623
624 return 0;
625 }
626
627 EXPORT_SYMBOL(dma_get_device_descriptor_ring);
628
629 /****************************************************************************/
630 /**
631 * Configures a DMA channel.
632 *
633 * @return
634 * >= 0 - Initialization was successful.
635 *
636 * -EBUSY - Device is currently being used.
637 * -ENODEV - Device handed in is invalid.
638 */
639 /****************************************************************************/
640
641 static int ConfigChannel(DMA_Handle_t handle)
642 {
643 DMA_Channel_t *channel;
644 DMA_DeviceAttribute_t *devAttr;
645 int controllerIdx;
646
647 channel = HandleToChannel(handle);
648 if (channel == NULL) {
649 return -ENODEV;
650 }
651 devAttr = &DMA_gDeviceAttribute[channel->devType];
652 controllerIdx = CONTROLLER_FROM_HANDLE(handle);
653
654 if ((devAttr->flags & DMA_DEVICE_FLAG_PORT_PER_DMAC) != 0) {
655 if (devAttr->config.transferType ==
656 dmacHw_TRANSFER_TYPE_MEM_TO_PERIPHERAL) {
657 devAttr->config.dstPeripheralPort =
658 devAttr->dmacPort[controllerIdx];
659 } else if (devAttr->config.transferType ==
660 dmacHw_TRANSFER_TYPE_PERIPHERAL_TO_MEM) {
661 devAttr->config.srcPeripheralPort =
662 devAttr->dmacPort[controllerIdx];
663 }
664 }
665
666 if (dmacHw_configChannel(channel->dmacHwHandle, &devAttr->config) != 0) {
667 printk(KERN_ERR "ConfigChannel: dmacHw_configChannel failed\n");
668 return -EIO;
669 }
670
671 return 0;
672 }
673
674 /****************************************************************************/
675 /**
676 * Initializes all of the data structures associated with the DMA.
677 * @return
678 * >= 0 - Initialization was successful.
679 *
680 * -EBUSY - Device is currently being used.
681 * -ENODEV - Device handed in is invalid.
682 */
683 /****************************************************************************/
684
685 int dma_init(void)
686 {
687 int rc = 0;
688 int controllerIdx;
689 int channelIdx;
690 DMA_Device_t devIdx;
691 DMA_Channel_t *channel;
692 DMA_Handle_t dedicatedHandle;
693
694 memset(&gDMA, 0, sizeof(gDMA));
695
696 sema_init(&gDMA.lock, 0);
697 init_waitqueue_head(&gDMA.freeChannelQ);
698
699 /* Initialize the Hardware */
700
701 dmacHw_initDma();
702
703 /* Start off by marking all of the DMA channels as shared. */
704
705 for (controllerIdx = 0; controllerIdx < DMA_NUM_CONTROLLERS;
706 controllerIdx++) {
707 for (channelIdx = 0; channelIdx < DMA_NUM_CHANNELS;
708 channelIdx++) {
709 channel =
710 &gDMA.controller[controllerIdx].channel[channelIdx];
711
712 channel->flags = 0;
713 channel->devType = DMA_DEVICE_NONE;
714 channel->lastDevType = DMA_DEVICE_NONE;
715
716 #if (DMA_DEBUG_TRACK_RESERVATION)
717 channel->fileName = "";
718 channel->lineNum = 0;
719 #endif
720
721 channel->dmacHwHandle =
722 dmacHw_getChannelHandle(dmacHw_MAKE_CHANNEL_ID
723 (controllerIdx,
724 channelIdx));
725 dmacHw_initChannel(channel->dmacHwHandle);
726 }
727 }
728
729 /* Record any special attributes that channels may have */
730
731 gDMA.controller[0].channel[0].flags |= DMA_CHANNEL_FLAG_LARGE_FIFO;
732 gDMA.controller[0].channel[1].flags |= DMA_CHANNEL_FLAG_LARGE_FIFO;
733 gDMA.controller[1].channel[0].flags |= DMA_CHANNEL_FLAG_LARGE_FIFO;
734 gDMA.controller[1].channel[1].flags |= DMA_CHANNEL_FLAG_LARGE_FIFO;
735
736 /* Now walk through and record the dedicated channels. */
737
738 for (devIdx = 0; devIdx < DMA_NUM_DEVICE_ENTRIES; devIdx++) {
739 DMA_DeviceAttribute_t *devAttr = &DMA_gDeviceAttribute[devIdx];
740
741 if (((devAttr->flags & DMA_DEVICE_FLAG_NO_ISR) != 0)
742 && ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) == 0)) {
743 printk(KERN_ERR
744 "DMA Device: %s Can only request NO_ISR for dedicated devices\n",
745 devAttr->name);
746 rc = -EINVAL;
747 goto out;
748 }
749
750 if ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) != 0) {
751 /* This is a dedicated device. Mark the channel as being reserved. */
752
753 if (devAttr->dedicatedController >= DMA_NUM_CONTROLLERS) {
754 printk(KERN_ERR
755 "DMA Device: %s DMA Controller %d is out of range\n",
756 devAttr->name,
757 devAttr->dedicatedController);
758 rc = -EINVAL;
759 goto out;
760 }
761
762 if (devAttr->dedicatedChannel >= DMA_NUM_CHANNELS) {
763 printk(KERN_ERR
764 "DMA Device: %s DMA Channel %d is out of range\n",
765 devAttr->name,
766 devAttr->dedicatedChannel);
767 rc = -EINVAL;
768 goto out;
769 }
770
771 dedicatedHandle =
772 MAKE_HANDLE(devAttr->dedicatedController,
773 devAttr->dedicatedChannel);
774 channel = HandleToChannel(dedicatedHandle);
775
776 if ((channel->flags & DMA_CHANNEL_FLAG_IS_DEDICATED) !=
777 0) {
778 printk
779 ("DMA Device: %s attempting to use same DMA Controller:Channel (%d:%d) as %s\n",
780 devAttr->name,
781 devAttr->dedicatedController,
782 devAttr->dedicatedChannel,
783 DMA_gDeviceAttribute[channel->devType].
784 name);
785 rc = -EBUSY;
786 goto out;
787 }
788
789 channel->flags |= DMA_CHANNEL_FLAG_IS_DEDICATED;
790 channel->devType = devIdx;
791
792 if (devAttr->flags & DMA_DEVICE_FLAG_NO_ISR) {
793 channel->flags |= DMA_CHANNEL_FLAG_NO_ISR;
794 }
795
796 /* For dedicated channels, we can go ahead and configure the DMA channel now */
797 /* as well. */
798
799 ConfigChannel(dedicatedHandle);
800 }
801 }
802
803 /* Go through and register the interrupt handlers */
804
805 for (controllerIdx = 0; controllerIdx < DMA_NUM_CONTROLLERS;
806 controllerIdx++) {
807 for (channelIdx = 0; channelIdx < DMA_NUM_CHANNELS;
808 channelIdx++) {
809 channel =
810 &gDMA.controller[controllerIdx].channel[channelIdx];
811
812 if ((channel->flags & DMA_CHANNEL_FLAG_NO_ISR) == 0) {
813 snprintf(channel->name, sizeof(channel->name),
814 "dma %d:%d %s", controllerIdx,
815 channelIdx,
816 channel->devType ==
817 DMA_DEVICE_NONE ? "" :
818 DMA_gDeviceAttribute[channel->devType].
819 name);
820
821 rc =
822 request_irq(IRQ_DMA0C0 +
823 (controllerIdx *
824 DMA_NUM_CHANNELS) +
825 channelIdx,
826 dma_interrupt_handler,
827 IRQF_DISABLED, channel->name,
828 channel);
829 if (rc != 0) {
830 printk(KERN_ERR
831 "request_irq for IRQ_DMA%dC%d failed\n",
832 controllerIdx, channelIdx);
833 }
834 }
835 }
836 }
837
838 /* Create /proc/dma/channels and /proc/dma/devices */
839
840 gDmaDir = proc_mkdir("dma", NULL);
841
842 if (gDmaDir == NULL) {
843 printk(KERN_ERR "Unable to create /proc/dma\n");
844 } else {
845 create_proc_read_entry("channels", 0, gDmaDir,
846 dma_proc_read_channels, NULL);
847 create_proc_read_entry("devices", 0, gDmaDir,
848 dma_proc_read_devices, NULL);
849 create_proc_read_entry("mem-type", 0, gDmaDir,
850 dma_proc_read_mem_type, NULL);
851 }
852
853 out:
854
855 up(&gDMA.lock);
856
857 return rc;
858 }
859
860 /****************************************************************************/
861 /**
862 * Reserves a channel for use with @a dev. If the device is setup to use
863 * a shared channel, then this function will block until a free channel
864 * becomes available.
865 *
866 * @return
867 * >= 0 - A valid DMA Handle.
868 * -EBUSY - Device is currently being used.
869 * -ENODEV - Device handed in is invalid.
870 */
871 /****************************************************************************/
872
873 #if (DMA_DEBUG_TRACK_RESERVATION)
874 DMA_Handle_t dma_request_channel_dbg
875 (DMA_Device_t dev, const char *fileName, int lineNum)
876 #else
877 DMA_Handle_t dma_request_channel(DMA_Device_t dev)
878 #endif
879 {
880 DMA_Handle_t handle;
881 DMA_DeviceAttribute_t *devAttr;
882 DMA_Channel_t *channel;
883 int controllerIdx;
884 int controllerIdx2;
885 int channelIdx;
886
887 if (down_interruptible(&gDMA.lock) < 0) {
888 return -ERESTARTSYS;
889 }
890
891 if ((dev < 0) || (dev >= DMA_NUM_DEVICE_ENTRIES)) {
892 handle = -ENODEV;
893 goto out;
894 }
895 devAttr = &DMA_gDeviceAttribute[dev];
896
897 #if (DMA_DEBUG_TRACK_RESERVATION)
898 {
899 char *s;
900
901 s = strrchr(fileName, '/');
902 if (s != NULL) {
903 fileName = s + 1;
904 }
905 }
906 #endif
907 if ((devAttr->flags & DMA_DEVICE_FLAG_IN_USE) != 0) {
908 /* This device has already been requested and not been freed */
909
910 printk(KERN_ERR "%s: device %s is already requested\n",
911 __func__, devAttr->name);
912 handle = -EBUSY;
913 goto out;
914 }
915
916 if ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) != 0) {
917 /* This device has a dedicated channel. */
918
919 channel =
920 &gDMA.controller[devAttr->dedicatedController].
921 channel[devAttr->dedicatedChannel];
922 if ((channel->flags & DMA_CHANNEL_FLAG_IN_USE) != 0) {
923 handle = -EBUSY;
924 goto out;
925 }
926
927 channel->flags |= DMA_CHANNEL_FLAG_IN_USE;
928 devAttr->flags |= DMA_DEVICE_FLAG_IN_USE;
929
930 #if (DMA_DEBUG_TRACK_RESERVATION)
931 channel->fileName = fileName;
932 channel->lineNum = lineNum;
933 #endif
934 handle =
935 MAKE_HANDLE(devAttr->dedicatedController,
936 devAttr->dedicatedChannel);
937 goto out;
938 }
939
940 /* This device needs to use one of the shared channels. */
941
942 handle = DMA_INVALID_HANDLE;
943 while (handle == DMA_INVALID_HANDLE) {
944 /* Scan through the shared channels and see if one is available */
945
946 for (controllerIdx2 = 0; controllerIdx2 < DMA_NUM_CONTROLLERS;
947 controllerIdx2++) {
948 /* Check to see if we should try on controller 1 first. */
949
950 controllerIdx = controllerIdx2;
951 if ((devAttr->
952 flags & DMA_DEVICE_FLAG_ALLOC_DMA1_FIRST) != 0) {
953 controllerIdx = 1 - controllerIdx;
954 }
955
956 /* See if the device is available on the controller being tested */
957
958 if ((devAttr->
959 flags & (DMA_DEVICE_FLAG_ON_DMA0 << controllerIdx))
960 != 0) {
961 for (channelIdx = 0;
962 channelIdx < DMA_NUM_CHANNELS;
963 channelIdx++) {
964 channel =
965 &gDMA.controller[controllerIdx].
966 channel[channelIdx];
967
968 if (((channel->
969 flags &
970 DMA_CHANNEL_FLAG_IS_DEDICATED) ==
971 0)
972 &&
973 ((channel->
974 flags & DMA_CHANNEL_FLAG_IN_USE)
975 == 0)) {
976 if (((channel->
977 flags &
978 DMA_CHANNEL_FLAG_LARGE_FIFO)
979 != 0)
980 &&
981 ((devAttr->
982 flags &
983 DMA_DEVICE_FLAG_ALLOW_LARGE_FIFO)
984 == 0)) {
985 /* This channel is a large fifo - don't tie it up */
986 /* with devices that we don't want using it. */
987
988 continue;
989 }
990
991 channel->flags |=
992 DMA_CHANNEL_FLAG_IN_USE;
993 channel->devType = dev;
994 devAttr->flags |=
995 DMA_DEVICE_FLAG_IN_USE;
996
997 #if (DMA_DEBUG_TRACK_RESERVATION)
998 channel->fileName = fileName;
999 channel->lineNum = lineNum;
1000 #endif
1001 handle =
1002 MAKE_HANDLE(controllerIdx,
1003 channelIdx);
1004
1005 /* Now that we've reserved the channel - we can go ahead and configure it */
1006
1007 if (ConfigChannel(handle) != 0) {
1008 handle = -EIO;
1009 printk(KERN_ERR
1010 "dma_request_channel: ConfigChannel failed\n");
1011 }
1012 goto out;
1013 }
1014 }
1015 }
1016 }
1017
1018 /* No channels are currently available. Let's wait for one to free up. */
1019
1020 {
1021 DEFINE_WAIT(wait);
1022
1023 prepare_to_wait(&gDMA.freeChannelQ, &wait,
1024 TASK_INTERRUPTIBLE);
1025 up(&gDMA.lock);
1026 schedule();
1027 finish_wait(&gDMA.freeChannelQ, &wait);
1028
1029 if (signal_pending(current)) {
1030 /* We don't currently hold gDMA.lock, so we return directly */
1031
1032 return -ERESTARTSYS;
1033 }
1034 }
1035
1036 if (down_interruptible(&gDMA.lock)) {
1037 return -ERESTARTSYS;
1038 }
1039 }
1040
1041 out:
1042 up(&gDMA.lock);
1043
1044 return handle;
1045 }
1046
1047 /* Create both _dbg and non _dbg functions for modules. */
1048
1049 #if (DMA_DEBUG_TRACK_RESERVATION)
1050 #undef dma_request_channel
1051 DMA_Handle_t dma_request_channel(DMA_Device_t dev)
1052 {
1053 return dma_request_channel_dbg(dev, __FILE__, __LINE__);
1054 }
1055
1056 EXPORT_SYMBOL(dma_request_channel_dbg);
1057 #endif
1058 EXPORT_SYMBOL(dma_request_channel);
1059
1060 /****************************************************************************/
1061 /**
1062 * Frees a previously allocated DMA Handle.
1063 */
1064 /****************************************************************************/
1065
1066 int dma_free_channel(DMA_Handle_t handle /* DMA handle. */
1067 ) {
1068 int rc = 0;
1069 DMA_Channel_t *channel;
1070 DMA_DeviceAttribute_t *devAttr;
1071
1072 if (down_interruptible(&gDMA.lock) < 0) {
1073 return -ERESTARTSYS;
1074 }
1075
1076 channel = HandleToChannel(handle);
1077 if (channel == NULL) {
1078 rc = -EINVAL;
1079 goto out;
1080 }
1081
1082 devAttr = &DMA_gDeviceAttribute[channel->devType];
1083
1084 if ((channel->flags & DMA_CHANNEL_FLAG_IS_DEDICATED) == 0) {
1085 channel->lastDevType = channel->devType;
1086 channel->devType = DMA_DEVICE_NONE;
1087 }
1088 channel->flags &= ~DMA_CHANNEL_FLAG_IN_USE;
1089 devAttr->flags &= ~DMA_DEVICE_FLAG_IN_USE;
1090
1091 out:
1092 up(&gDMA.lock);
1093
1094 wake_up_interruptible(&gDMA.freeChannelQ);
1095
1096 return rc;
1097 }
1098
1099 EXPORT_SYMBOL(dma_free_channel);
1100
1101 /****************************************************************************/
1102 /**
1103 * Determines if a given device has been configured as using a shared
1104 * channel.
1105 *
1106 * @return
1107 * 0 Device uses a dedicated channel
1108 * > zero Device uses a shared channel
1109 * < zero Error code
1110 */
1111 /****************************************************************************/
1112
1113 int dma_device_is_channel_shared(DMA_Device_t device /* Device to check. */
1114 ) {
1115 DMA_DeviceAttribute_t *devAttr;
1116
1117 if (!IsDeviceValid(device)) {
1118 return -ENODEV;
1119 }
1120 devAttr = &DMA_gDeviceAttribute[device];
1121
1122 return ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) == 0);
1123 }
1124
1125 EXPORT_SYMBOL(dma_device_is_channel_shared);
1126
1127 /****************************************************************************/
1128 /**
1129 * Allocates buffers for the descriptors. This is normally done automatically
1130 * but needs to be done explicitly when initiating a dma from interrupt
1131 * context.
1132 *
1133 * @return
1134 * 0 Descriptors were allocated successfully
1135 * -EINVAL Invalid device type for this kind of transfer
1136 * (i.e. the device is _MEM_TO_DEV and not _DEV_TO_MEM)
1137 * -ENOMEM Memory exhausted
1138 */
1139 /****************************************************************************/
1140
1141 int dma_alloc_descriptors(DMA_Handle_t handle, /* DMA Handle */
1142 dmacHw_TRANSFER_TYPE_e transferType, /* Type of transfer being performed */
1143 dma_addr_t srcData, /* Place to get data to write to device */
1144 dma_addr_t dstData, /* Pointer to device data address */
1145 size_t numBytes /* Number of bytes to transfer to the device */
1146 ) {
1147 DMA_Channel_t *channel;
1148 DMA_DeviceAttribute_t *devAttr;
1149 int numDescriptors;
1150 size_t ringBytesRequired;
1151 int rc = 0;
1152
1153 channel = HandleToChannel(handle);
1154 if (channel == NULL) {
1155 return -ENODEV;
1156 }
1157
1158 devAttr = &DMA_gDeviceAttribute[channel->devType];
1159
1160 if (devAttr->config.transferType != transferType) {
1161 return -EINVAL;
1162 }
1163
1164 /* Figure out how many descriptors we need. */
1165
1166 /* printk("srcData: 0x%08x dstData: 0x%08x, numBytes: %d\n", */
1167 /* srcData, dstData, numBytes); */
1168
1169 numDescriptors = dmacHw_calculateDescriptorCount(&devAttr->config,
1170 (void *)srcData,
1171 (void *)dstData,
1172 numBytes);
1173 if (numDescriptors < 0) {
1174 printk(KERN_ERR "%s: dmacHw_calculateDescriptorCount failed\n",
1175 __func__);
1176 return -EINVAL;
1177 }
1178
1179 /* Check to see if we can reuse the existing descriptor ring, or if we need to allocate */
1180 /* a new one. */
1181
1182 ringBytesRequired = dmacHw_descriptorLen(numDescriptors);
1183
1184 /* printk("ringBytesRequired: %d\n", ringBytesRequired); */
1185
1186 if (ringBytesRequired > devAttr->ring.bytesAllocated) {
1187 /* Make sure that this code path is never taken from interrupt context. */
1188 /* It's OK for an interrupt to initiate a DMA transfer, but the descriptor */
1189 /* allocation needs to have already been done. */
1190
1191 might_sleep();
1192
1193 /* Free the old descriptor ring and allocate a new one. */
1194
1195 dma_free_descriptor_ring(&devAttr->ring);
1196
1197 /* And allocate a new one. */
1198
1199 rc =
1200 dma_alloc_descriptor_ring(&devAttr->ring,
1201 numDescriptors);
1202 if (rc < 0) {
1203 printk(KERN_ERR
1204 "%s: dma_alloc_descriptor_ring(%d) failed\n",
1205 __func__, numDescriptors);
1206 return rc;
1207 }
1208 /* Setup the descriptor for this transfer */
1209
1210 if (dmacHw_initDescriptor(devAttr->ring.virtAddr,
1211 devAttr->ring.physAddr,
1212 devAttr->ring.bytesAllocated,
1213 numDescriptors) < 0) {
1214 printk(KERN_ERR "%s: dmacHw_initDescriptor failed\n",
1215 __func__);
1216 return -EINVAL;
1217 }
1218 } else {
1219 /* We've already got enough ring buffer allocated. All we need to do is reset */
1220 /* any control information, just in case the previous DMA was stopped. */
1221
1222 dmacHw_resetDescriptorControl(devAttr->ring.virtAddr);
1223 }
1224
1225 /* dma_alloc/free both set the prevSrc/DstData to 0. If they happen to be the same */
1226 /* as last time, then we don't need to call setDataDescriptor again. */
1227
1228 if (dmacHw_setDataDescriptor(&devAttr->config,
1229 devAttr->ring.virtAddr,
1230 (void *)srcData,
1231 (void *)dstData, numBytes) < 0) {
1232 printk(KERN_ERR "%s: dmacHw_setDataDescriptor failed\n",
1233 __func__);
1234 return -EINVAL;
1235 }
1236
1237 /* Remember the critical information for this transfer so that we can eliminate */
1238 /* another call to dma_alloc_descriptors if the caller reuses the same buffers */
1239
1240 devAttr->prevSrcData = srcData;
1241 devAttr->prevDstData = dstData;
1242 devAttr->prevNumBytes = numBytes;
1243
1244 return 0;
1245 }
1246
1247 EXPORT_SYMBOL(dma_alloc_descriptors);
1248
1249 /****************************************************************************/
1250 /**
1251 * Allocates and sets up descriptors for a double buffered circular buffer.
1252 *
1253 * This is primarily intended to be used for things like the ingress samples
1254 * from a microphone.
1255 *
1256 * @return
1257 * > 0 Number of descriptors actually allocated.
1258 * -EINVAL Invalid device type for this kind of transfer
1259 * (i.e. the device is _MEM_TO_DEV and not _DEV_TO_MEM)
1260 * -ENOMEM Memory exhausted
1261 */
1262 /****************************************************************************/
1263
1264 int dma_alloc_double_dst_descriptors(DMA_Handle_t handle, /* DMA Handle */
1265 dma_addr_t srcData, /* Physical address of source data */
1266 dma_addr_t dstData1, /* Physical address of first destination buffer */
1267 dma_addr_t dstData2, /* Physical address of second destination buffer */
1268 size_t numBytes /* Number of bytes in each destination buffer */
1269 ) {
1270 DMA_Channel_t *channel;
1271 DMA_DeviceAttribute_t *devAttr;
1272 int numDst1Descriptors;
1273 int numDst2Descriptors;
1274 int numDescriptors;
1275 size_t ringBytesRequired;
1276 int rc = 0;
1277
1278 channel = HandleToChannel(handle);
1279 if (channel == NULL) {
1280 return -ENODEV;
1281 }
1282
1283 devAttr = &DMA_gDeviceAttribute[channel->devType];
1284
1285 /* Figure out how many descriptors we need. */
1286
1287 /* printk("srcData: 0x%08x dstData: 0x%08x, numBytes: %d\n", */
1288 /* srcData, dstData, numBytes); */
1289
1290 numDst1Descriptors =
1291 dmacHw_calculateDescriptorCount(&devAttr->config, (void *)srcData,
1292 (void *)dstData1, numBytes);
1293 if (numDst1Descriptors < 0) {
1294 return -EINVAL;
1295 }
1296 numDst2Descriptors =
1297 dmacHw_calculateDescriptorCount(&devAttr->config, (void *)srcData,
1298 (void *)dstData2, numBytes);
1299 if (numDst2Descriptors < 0) {
1300 return -EINVAL;
1301 }
1302 numDescriptors = numDst1Descriptors + numDst2Descriptors;
1303 /* printk("numDescriptors: %d\n", numDescriptors); */
1304
1305 /* Check to see if we can reuse the existing descriptor ring, or if we need to allocate */
1306 /* a new one. */
1307
1308 ringBytesRequired = dmacHw_descriptorLen(numDescriptors);
1309
1310 /* printk("ringBytesRequired: %d\n", ringBytesRequired); */
1311
1312 if (ringBytesRequired > devAttr->ring.bytesAllocated) {
1313 /* Make sure that this code path is never taken from interrupt context. */
1314 /* It's OK for an interrupt to initiate a DMA transfer, but the descriptor */
1315 /* allocation needs to have already been done. */
1316
1317 might_sleep();
1318
1319 /* Free the old descriptor ring and allocate a new one. */
1320
1321 dma_free_descriptor_ring(&devAttr->ring);
1322
1323 /* And allocate a new one. */
1324
1325 rc =
1326 dma_alloc_descriptor_ring(&devAttr->ring,
1327 numDescriptors);
1328 if (rc < 0) {
1329 printk(KERN_ERR
1330 "%s: dma_alloc_descriptor_ring(%d) failed\n",
1331 __func__, ringBytesRequired);
1332 return rc;
1333 }
1334 }
1335
1336 /* Setup the descriptor for this transfer. Since this function is used with */
1337 /* CONTINUOUS DMA operations, we need to reinitialize every time, otherwise */
1338 /* setDataDescriptor will keep trying to append onto the end. */
1339
1340 if (dmacHw_initDescriptor(devAttr->ring.virtAddr,
1341 devAttr->ring.physAddr,
1342 devAttr->ring.bytesAllocated,
1343 numDescriptors) < 0) {
1344 printk(KERN_ERR "%s: dmacHw_initDescriptor failed\n", __func__);
1345 return -EINVAL;
1346 }
1347
1348 /* dma_alloc/free both set the prevSrc/DstData to 0. If they happen to be the same */
1349 /* as last time, then we don't need to call setDataDescriptor again. */
1350
1351 if (dmacHw_setDataDescriptor(&devAttr->config,
1352 devAttr->ring.virtAddr,
1353 (void *)srcData,
1354 (void *)dstData1, numBytes) < 0) {
1355 printk(KERN_ERR "%s: dmacHw_setDataDescriptor 1 failed\n",
1356 __func__);
1357 return -EINVAL;
1358 }
1359 if (dmacHw_setDataDescriptor(&devAttr->config,
1360 devAttr->ring.virtAddr,
1361 (void *)srcData,
1362 (void *)dstData2, numBytes) < 0) {
1363 printk(KERN_ERR "%s: dmacHw_setDataDescriptor 2 failed\n",
1364 __func__);
1365 return -EINVAL;
1366 }
1367
1368 /* You should use dma_start_transfer rather than dma_transfer_xxx so we don't */
1369 /* try to make the 'prev' variables right. */
1370
1371 devAttr->prevSrcData = 0;
1372 devAttr->prevDstData = 0;
1373 devAttr->prevNumBytes = 0;
1374
1375 return numDescriptors;
1376 }
1377
1378 EXPORT_SYMBOL(dma_alloc_double_dst_descriptors);
1379
1380 /****************************************************************************/
1381 /**
1382 * Initiates a transfer when the descriptors have already been setup.
1383 *
1384 * This is a special case, and normally, the dma_transfer_xxx functions should
1385 * be used.
1386 *
1387 * @return
1388 * 0 Transfer was started successfully
1389 * -ENODEV Invalid handle
1390 */
1391 /****************************************************************************/
1392
1393 int dma_start_transfer(DMA_Handle_t handle)
1394 {
1395 DMA_Channel_t *channel;
1396 DMA_DeviceAttribute_t *devAttr;
1397
1398 channel = HandleToChannel(handle);
1399 if (channel == NULL) {
1400 return -ENODEV;
1401 }
1402 devAttr = &DMA_gDeviceAttribute[channel->devType];
1403
1404 dmacHw_initiateTransfer(channel->dmacHwHandle, &devAttr->config,
1405 devAttr->ring.virtAddr);
1406
1407 /* Since we got this far, everything went successfully */
1408
1409 return 0;
1410 }
1411
1412 EXPORT_SYMBOL(dma_start_transfer);
1413
1414 /****************************************************************************/
1415 /**
1416 * Stops a previously started DMA transfer.
1417 *
1418 * @return
1419 * 0 Transfer was stopped successfully
1420 * -ENODEV Invalid handle
1421 */
1422 /****************************************************************************/
1423
1424 int dma_stop_transfer(DMA_Handle_t handle)
1425 {
1426 DMA_Channel_t *channel;
1427
1428 channel = HandleToChannel(handle);
1429 if (channel == NULL) {
1430 return -ENODEV;
1431 }
1432
1433 dmacHw_stopTransfer(channel->dmacHwHandle);
1434
1435 return 0;
1436 }
1437
1438 EXPORT_SYMBOL(dma_stop_transfer);
1439
1440 /****************************************************************************/
1441 /**
1442 * Waits for a DMA to complete by polling. This function is only intended
1443 * to be used for testing. Interrupts should be used for most DMA operations.
1444 */
1445 /****************************************************************************/
1446
1447 int dma_wait_transfer_done(DMA_Handle_t handle)
1448 {
1449 DMA_Channel_t *channel;
1450 dmacHw_TRANSFER_STATUS_e status;
1451
1452 channel = HandleToChannel(handle);
1453 if (channel == NULL) {
1454 return -ENODEV;
1455 }
1456
1457 while ((status =
1458 dmacHw_transferCompleted(channel->dmacHwHandle)) ==
1459 dmacHw_TRANSFER_STATUS_BUSY) {
1460 ;
1461 }
1462
1463 if (status == dmacHw_TRANSFER_STATUS_ERROR) {
1464 printk(KERN_ERR "%s: DMA transfer failed\n", __func__);
1465 return -EIO;
1466 }
1467 return 0;
1468 }
1469
1470 EXPORT_SYMBOL(dma_wait_transfer_done);
1471
1472 /****************************************************************************/
1473 /**
1474 * Initiates a DMA, allocating the descriptors as required.
1475 *
1476 * @return
1477 * 0 Transfer was started successfully
1478 * -EINVAL Invalid device type for this kind of transfer
1479 * (i.e. the device is _DEV_TO_MEM and not _MEM_TO_DEV)
1480 */
1481 /****************************************************************************/
1482
1483 int dma_transfer(DMA_Handle_t handle, /* DMA Handle */
1484 dmacHw_TRANSFER_TYPE_e transferType, /* Type of transfer being performed */
1485 dma_addr_t srcData, /* Place to get data to write to device */
1486 dma_addr_t dstData, /* Pointer to device data address */
1487 size_t numBytes /* Number of bytes to transfer to the device */
1488 ) {
1489 DMA_Channel_t *channel;
1490 DMA_DeviceAttribute_t *devAttr;
1491 int rc = 0;
1492
1493 channel = HandleToChannel(handle);
1494 if (channel == NULL) {
1495 return -ENODEV;
1496 }
1497
1498 devAttr = &DMA_gDeviceAttribute[channel->devType];
1499
1500 if (devAttr->config.transferType != transferType) {
1501 return -EINVAL;
1502 }
1503
1504 /* We keep track of the information about the previous request for this */
1505 /* device, and if the attributes match, then we can use the descriptors we setup */
1506 /* the last time, and not have to reinitialize everything. */
1507
1508 {
1509 rc =
1510 dma_alloc_descriptors(handle, transferType, srcData,
1511 dstData, numBytes);
1512 if (rc != 0) {
1513 return rc;
1514 }
1515 }
1516
1517 /* And kick off the transfer */
1518
1519 devAttr->numBytes = numBytes;
1520 devAttr->transferStartTime = timer_get_tick_count();
1521
1522 dmacHw_initiateTransfer(channel->dmacHwHandle, &devAttr->config,
1523 devAttr->ring.virtAddr);
1524
1525 /* Since we got this far, everything went successfully */
1526
1527 return 0;
1528 }
1529
1530 EXPORT_SYMBOL(dma_transfer);
1531
1532 /****************************************************************************/
1533 /**
1534 * Set the callback function which will be called when a transfer completes.
1535 * If a NULL callback function is set, then no callback will occur.
1536 *
1537 * @note @a devHandler will be called from IRQ context.
1538 *
1539 * @return
1540 * 0 - Success
1541 * -ENODEV - Device handed in is invalid.
1542 */
1543 /****************************************************************************/
1544
1545 int dma_set_device_handler(DMA_Device_t dev, /* Device to set the callback for. */
1546 DMA_DeviceHandler_t devHandler, /* Function to call when the DMA completes */
1547 void *userData /* Pointer which will be passed to devHandler. */
1548 ) {
1549 DMA_DeviceAttribute_t *devAttr;
1550 unsigned long flags;
1551
1552 if (!IsDeviceValid(dev)) {
1553 return -ENODEV;
1554 }
1555 devAttr = &DMA_gDeviceAttribute[dev];
1556
1557 local_irq_save(flags);
1558
1559 devAttr->userData = userData;
1560 devAttr->devHandler = devHandler;
1561
1562 local_irq_restore(flags);
1563
1564 return 0;
1565 }
1566
1567 EXPORT_SYMBOL(dma_set_device_handler);
1568
1569 /****************************************************************************/
1570 /**
1571 * Initializes a memory mapping structure
1572 */
1573 /****************************************************************************/
1574
1575 int dma_init_mem_map(DMA_MemMap_t *memMap)
1576 {
1577 memset(memMap, 0, sizeof(*memMap));
1578
1579 sema_init(&memMap->lock, 1);
1580
1581 return 0;
1582 }
1583
1584 EXPORT_SYMBOL(dma_init_mem_map);
1585
1586 /****************************************************************************/
1587 /**
1588 * Releases any memory currently being held by a memory mapping structure.
1589 */
1590 /****************************************************************************/
1591
1592 int dma_term_mem_map(DMA_MemMap_t *memMap)
1593 {
1594 down(&memMap->lock); /* Just being paranoid */
1595
1596 /* Free up any allocated memory */
1597
1598 up(&memMap->lock);
1599 memset(memMap, 0, sizeof(*memMap));
1600
1601 return 0;
1602 }
1603
1604 EXPORT_SYMBOL(dma_term_mem_map);
1605
1606 /****************************************************************************/
1607 /**
1608 * Looks at a memory address and categorizes it.
1609 *
1610 * @return One of the values from the DMA_MemType_t enumeration.
1611 */
1612 /****************************************************************************/
1613
1614 DMA_MemType_t dma_mem_type(void *addr)
1615 {
1616 unsigned long addrVal = (unsigned long)addr;
1617
1618 if (addrVal >= CONSISTENT_BASE) {
1619 /* NOTE: DMA virtual memory space starts at 0xFFxxxxxx */
1620
1621 /* dma_alloc_xxx pages are physically and virtually contiguous */
1622
1623 return DMA_MEM_TYPE_DMA;
1624 }
1625
1626 /* Technically, we could add one more classification. Addresses between VMALLOC_END */
1627 /* and the beginning of the DMA virtual address could be considered to be I/O space. */
1628 /* Right now, nobody cares about this particular classification, so we ignore it. */
1629
1630 if (is_vmalloc_addr(addr)) {
1631 /* Address comes from the vmalloc'd region. Pages are virtually */
1632 /* contiguous but NOT physically contiguous */
1633
1634 return DMA_MEM_TYPE_VMALLOC;
1635 }
1636
1637 if (addrVal >= PAGE_OFFSET) {
1638 /* PAGE_OFFSET is typically 0xC0000000 */
1639
1640 /* kmalloc'd pages are physically contiguous */
1641
1642 return DMA_MEM_TYPE_KMALLOC;
1643 }
1644
1645 return DMA_MEM_TYPE_USER;
1646 }
1647
1648 EXPORT_SYMBOL(dma_mem_type);
1649
1650 /****************************************************************************/
1651 /**
1652 * Looks at a memory address and determines if we support DMA'ing to/from
1653 * that type of memory.
1654 *
1655 * @return boolean -
1656 * return value != 0 means dma supported
1657 * return value == 0 means dma not supported
1658 */
1659 /****************************************************************************/
1660
1661 int dma_mem_supports_dma(void *addr)
1662 {
1663 DMA_MemType_t memType = dma_mem_type(addr);
1664
1665 return (memType == DMA_MEM_TYPE_DMA)
1666 #if ALLOW_MAP_OF_KMALLOC_MEMORY
1667 || (memType == DMA_MEM_TYPE_KMALLOC)
1668 #endif
1669 || (memType == DMA_MEM_TYPE_USER);
1670 }
1671
1672 EXPORT_SYMBOL(dma_mem_supports_dma);
1673
1674 /****************************************************************************/
1675 /**
1676 * Maps in a memory region such that it can be used for performing a DMA.
1677 *
1678 * @return
1679 */
1680 /****************************************************************************/
1681
1682 int dma_map_start(DMA_MemMap_t *memMap, /* Stores state information about the map */
1683 enum dma_data_direction dir /* Direction that the mapping will be going */
1684 ) {
1685 int rc;
1686
1687 down(&memMap->lock);
1688
1689 DMA_MAP_PRINT("memMap: %p\n", memMap);
1690
1691 if (memMap->inUse) {
1692 printk(KERN_ERR "%s: memory map %p is already being used\n",
1693 __func__, memMap);
1694 rc = -EBUSY;
1695 goto out;
1696 }
1697
1698 memMap->inUse = 1;
1699 memMap->dir = dir;
1700 memMap->numRegionsUsed = 0;
1701
1702 rc = 0;
1703
1704 out:
1705
1706 DMA_MAP_PRINT("returning %d", rc);
1707
1708 up(&memMap->lock);
1709
1710 return rc;
1711 }
1712
1713 EXPORT_SYMBOL(dma_map_start);
1714
1715 /****************************************************************************/
1716 /**
1717 * Adds a segment of memory to a memory map. Each segment is both
1718 * physically and virtually contiguous.
1719 *
1720 * @return 0 on success, error code otherwise.
1721 */
1722 /****************************************************************************/
1723
1724 static int dma_map_add_segment(DMA_MemMap_t *memMap, /* Stores state information about the map */
1725 DMA_Region_t *region, /* Region that the segment belongs to */
1726 void *virtAddr, /* Virtual address of the segment being added */
1727 dma_addr_t physAddr, /* Physical address of the segment being added */
1728 size_t numBytes /* Number of bytes of the segment being added */
1729 ) {
1730 DMA_Segment_t *segment;
1731
1732 DMA_MAP_PRINT("memMap:%p va:%p pa:0x%x #:%d\n", memMap, virtAddr,
1733 physAddr, numBytes);
1734
1735 /* Sanity check */
1736
1737 if (((unsigned long)virtAddr < (unsigned long)region->virtAddr)
1738 || (((unsigned long)virtAddr + numBytes)) >
1739 ((unsigned long)region->virtAddr + region->numBytes)) {
1740 printk(KERN_ERR
1741 "%s: virtAddr %p is outside region @ %p len: %d\n",
1742 __func__, virtAddr, region->virtAddr, region->numBytes);
1743 return -EINVAL;
1744 }
1745
1746 if (region->numSegmentsUsed > 0) {
1747 /* Check to see if this segment is physically contiguous with the previous one */
1748
1749 segment = &region->segment[region->numSegmentsUsed - 1];
1750
1751 if ((segment->physAddr + segment->numBytes) == physAddr) {
1752 /* It is - just add on to the end */
1753
1754 DMA_MAP_PRINT("appending %d bytes to last segment\n",
1755 numBytes);
1756
1757 segment->numBytes += numBytes;
1758
1759 return 0;
1760 }
1761 }
1762
1763 /* Reallocate to hold more segments, if required. */
1764
1765 if (region->numSegmentsUsed >= region->numSegmentsAllocated) {
1766 DMA_Segment_t *newSegment;
1767 size_t oldSize =
1768 region->numSegmentsAllocated * sizeof(*newSegment);
1769 int newAlloc = region->numSegmentsAllocated + 4;
1770 size_t newSize = newAlloc * sizeof(*newSegment);
1771
1772 newSegment = kmalloc(newSize, GFP_KERNEL);
1773 if (newSegment == NULL) {
1774 return -ENOMEM;
1775 }
1776 memcpy(newSegment, region->segment, oldSize);
1777 memset(&((uint8_t *) newSegment)[oldSize], 0,
1778 newSize - oldSize);
1779 kfree(region->segment);
1780
1781 region->numSegmentsAllocated = newAlloc;
1782 region->segment = newSegment;
1783 }
1784
1785 segment = &region->segment[region->numSegmentsUsed];
1786 region->numSegmentsUsed++;
1787
1788 segment->virtAddr = virtAddr;
1789 segment->physAddr = physAddr;
1790 segment->numBytes = numBytes;
1791
1792 DMA_MAP_PRINT("returning success\n");
1793
1794 return 0;
1795 }
1796
1797 /****************************************************************************/
1798 /**
1799 * Adds a region of memory to a memory map. Each region is virtually
1800 * contiguous, but not necessarily physically contiguous.
1801 *
1802 * @return 0 on success, error code otherwise.
1803 */
1804 /****************************************************************************/
1805
1806 int dma_map_add_region(DMA_MemMap_t *memMap, /* Stores state information about the map */
1807 void *mem, /* Virtual address that we want to get a map of */
1808 size_t numBytes /* Number of bytes being mapped */
1809 ) {
1810 unsigned long addr = (unsigned long)mem;
1811 unsigned int offset;
1812 int rc = 0;
1813 DMA_Region_t *region;
1814 dma_addr_t physAddr;
1815
1816 down(&memMap->lock);
1817
1818 DMA_MAP_PRINT("memMap:%p va:%p #:%d\n", memMap, mem, numBytes);
1819
1820 if (!memMap->inUse) {
1821 printk(KERN_ERR "%s: Make sure you call dma_map_start first\n",
1822 __func__);
1823 rc = -EINVAL;
1824 goto out;
1825 }
1826
1827 /* Reallocate to hold more regions. */
1828
1829 if (memMap->numRegionsUsed >= memMap->numRegionsAllocated) {
1830 DMA_Region_t *newRegion;
1831 size_t oldSize =
1832 memMap->numRegionsAllocated * sizeof(*newRegion);
1833 int newAlloc = memMap->numRegionsAllocated + 4;
1834 size_t newSize = newAlloc * sizeof(*newRegion);
1835
1836 newRegion = kmalloc(newSize, GFP_KERNEL);
1837 if (newRegion == NULL) {
1838 rc = -ENOMEM;
1839 goto out;
1840 }
1841 memcpy(newRegion, memMap->region, oldSize);
1842 memset(&((uint8_t *) newRegion)[oldSize], 0, newSize - oldSize);
1843
1844 kfree(memMap->region);
1845
1846 memMap->numRegionsAllocated = newAlloc;
1847 memMap->region = newRegion;
1848 }
1849
1850 region = &memMap->region[memMap->numRegionsUsed];
1851 memMap->numRegionsUsed++;
1852
1853 offset = addr & ~PAGE_MASK;
1854
1855 region->memType = dma_mem_type(mem);
1856 region->virtAddr = mem;
1857 region->numBytes = numBytes;
1858 region->numSegmentsUsed = 0;
1859 region->numLockedPages = 0;
1860 region->lockedPages = NULL;
1861
1862 switch (region->memType) {
1863 case DMA_MEM_TYPE_VMALLOC:
1864 {
1865 atomic_inc(&gDmaStatMemTypeVmalloc);
1866
1867 /* printk(KERN_ERR "%s: vmalloc'd pages are not supported\n", __func__); */
1868
1869 /* vmalloc'd pages are not physically contiguous */
1870
1871 rc = -EINVAL;
1872 break;
1873 }
1874
1875 case DMA_MEM_TYPE_KMALLOC:
1876 {
1877 atomic_inc(&gDmaStatMemTypeKmalloc);
1878
1879 /* kmalloc'd pages are physically contiguous, so they'll have exactly */
1880 /* one segment */
1881
1882 #if ALLOW_MAP_OF_KMALLOC_MEMORY
1883 physAddr =
1884 dma_map_single(NULL, mem, numBytes, memMap->dir);
1885 rc = dma_map_add_segment(memMap, region, mem, physAddr,
1886 numBytes);
1887 #else
1888 rc = -EINVAL;
1889 #endif
1890 break;
1891 }
1892
1893 case DMA_MEM_TYPE_DMA:
1894 {
1895 /* dma_alloc_xxx pages are physically contiguous */
1896
1897 atomic_inc(&gDmaStatMemTypeCoherent);
1898
1899 physAddr = (vmalloc_to_pfn(mem) << PAGE_SHIFT) + offset;
1900
1901 dma_sync_single_for_cpu(NULL, physAddr, numBytes,
1902 memMap->dir);
1903 rc = dma_map_add_segment(memMap, region, mem, physAddr,
1904 numBytes);
1905 break;
1906 }
1907
1908 case DMA_MEM_TYPE_USER:
1909 {
1910 size_t firstPageOffset;
1911 size_t firstPageSize;
1912 struct page **pages;
1913 struct task_struct *userTask;
1914
1915 atomic_inc(&gDmaStatMemTypeUser);
1916
1917 #if 1
1918 /* If the pages are user pages, then the dma_mem_map_set_user_task function */
1919 /* must have been previously called. */
1920
1921 if (memMap->userTask == NULL) {
1922 printk(KERN_ERR
1923 "%s: must call dma_mem_map_set_user_task when using user-mode memory\n",
1924 __func__);
1925 return -EINVAL;
1926 }
1927
1928 /* User pages need to be locked. */
1929
1930 firstPageOffset =
1931 (unsigned long)region->virtAddr & (PAGE_SIZE - 1);
1932 firstPageSize = PAGE_SIZE - firstPageOffset;
1933
1934 region->numLockedPages = (firstPageOffset
1935 + region->numBytes +
1936 PAGE_SIZE - 1) / PAGE_SIZE;
1937 pages =
1938 kmalloc(region->numLockedPages *
1939 sizeof(struct page *), GFP_KERNEL);
1940
1941 if (pages == NULL) {
1942 region->numLockedPages = 0;
1943 return -ENOMEM;
1944 }
1945
1946 userTask = memMap->userTask;
1947
1948 down_read(&userTask->mm->mmap_sem);
1949 rc = get_user_pages(userTask, /* task */
1950 userTask->mm, /* mm */
1951 (unsigned long)region->virtAddr, /* start */
1952 region->numLockedPages, /* len */
1953 memMap->dir == DMA_FROM_DEVICE, /* write */
1954 0, /* force */
1955 pages, /* pages (array of pointers to page) */
1956 NULL); /* vmas */
1957 up_read(&userTask->mm->mmap_sem);
1958
1959 if (rc != region->numLockedPages) {
1960 kfree(pages);
1961 region->numLockedPages = 0;
1962
1963 if (rc >= 0) {
1964 rc = -EINVAL;
1965 }
1966 } else {
1967 uint8_t *virtAddr = region->virtAddr;
1968 size_t bytesRemaining;
1969 int pageIdx;
1970
1971 rc = 0; /* Since get_user_pages returns +ve number */
1972
1973 region->lockedPages = pages;
1974
1975 /* We've locked the user pages. Now we need to walk them and figure */
1976 /* out the physical addresses. */
1977
1978 /* The first page may be partial */
1979
1980 dma_map_add_segment(memMap,
1981 region,
1982 virtAddr,
1983 PFN_PHYS(page_to_pfn
1984 (pages[0])) +
1985 firstPageOffset,
1986 firstPageSize);
1987
1988 virtAddr += firstPageSize;
1989 bytesRemaining =
1990 region->numBytes - firstPageSize;
1991
1992 for (pageIdx = 1;
1993 pageIdx < region->numLockedPages;
1994 pageIdx++) {
1995 size_t bytesThisPage =
1996 (bytesRemaining >
1997 PAGE_SIZE ? PAGE_SIZE :
1998 bytesRemaining);
1999
2000 DMA_MAP_PRINT
2001 ("pageIdx:%d pages[pageIdx]=%p pfn=%u phys=%u\n",
2002 pageIdx, pages[pageIdx],
2003 page_to_pfn(pages[pageIdx]),
2004 PFN_PHYS(page_to_pfn
2005 (pages[pageIdx])));
2006
2007 dma_map_add_segment(memMap,
2008 region,
2009 virtAddr,
2010 PFN_PHYS(page_to_pfn
2011 (pages
2012 [pageIdx])),
2013 bytesThisPage);
2014
2015 virtAddr += bytesThisPage;
2016 bytesRemaining -= bytesThisPage;
2017 }
2018 }
2019 #else
2020 printk(KERN_ERR
2021 "%s: User mode pages are not yet supported\n",
2022 __func__);
2023
2024 /* user pages are not physically contiguous */
2025
2026 rc = -EINVAL;
2027 #endif
2028 break;
2029 }
2030
2031 default:
2032 {
2033 printk(KERN_ERR "%s: Unsupported memory type: %d\n",
2034 __func__, region->memType);
2035
2036 rc = -EINVAL;
2037 break;
2038 }
2039 }
2040
2041 if (rc != 0) {
2042 memMap->numRegionsUsed--;
2043 }
2044
2045 out:
2046
2047 DMA_MAP_PRINT("returning %d\n", rc);
2048
2049 up(&memMap->lock);
2050
2051 return rc;
2052 }
2053
2054 EXPORT_SYMBOL(dma_map_add_segment);
2055
2056 /****************************************************************************/
2057 /**
2058 * Maps in a memory region such that it can be used for performing a DMA.
2059 *
2060 * @return 0 on success, error code otherwise.
2061 */
2062 /****************************************************************************/
2063
2064 int dma_map_mem(DMA_MemMap_t *memMap, /* Stores state information about the map */
2065 void *mem, /* Virtual address that we want to get a map of */
2066 size_t numBytes, /* Number of bytes being mapped */
2067 enum dma_data_direction dir /* Direction that the mapping will be going */
2068 ) {
2069 int rc;
2070
2071 rc = dma_map_start(memMap, dir);
2072 if (rc == 0) {
2073 rc = dma_map_add_region(memMap, mem, numBytes);
2074 if (rc < 0) {
2075 /* Since the add fails, this function will fail, and the caller won't */
2076 /* call unmap, so we need to do it here. */
2077
2078 dma_unmap(memMap, 0);
2079 }
2080 }
2081
2082 return rc;
2083 }
2084
2085 EXPORT_SYMBOL(dma_map_mem);
2086
2087 /****************************************************************************/
2088 /**
2089 * Setup a descriptor ring for a given memory map.
2090 *
2091 * It is assumed that the descriptor ring has already been initialized, and
2092 * this routine will only reallocate a new descriptor ring if the existing
2093 * one is too small.
2094 *
2095 * @return 0 on success, error code otherwise.
2096 */
2097 /****************************************************************************/
2098
2099 int dma_map_create_descriptor_ring(DMA_Device_t dev, /* DMA device (where the ring is stored) */
2100 DMA_MemMap_t *memMap, /* Memory map that will be used */
2101 dma_addr_t devPhysAddr /* Physical address of device */
2102 ) {
2103 int rc;
2104 int numDescriptors;
2105 DMA_DeviceAttribute_t *devAttr;
2106 DMA_Region_t *region;
2107 DMA_Segment_t *segment;
2108 dma_addr_t srcPhysAddr;
2109 dma_addr_t dstPhysAddr;
2110 int regionIdx;
2111 int segmentIdx;
2112
2113 devAttr = &DMA_gDeviceAttribute[dev];
2114
2115 down(&memMap->lock);
2116
2117 /* Figure out how many descriptors we need */
2118
2119 numDescriptors = 0;
2120 for (regionIdx = 0; regionIdx < memMap->numRegionsUsed; regionIdx++) {
2121 region = &memMap->region[regionIdx];
2122
2123 for (segmentIdx = 0; segmentIdx < region->numSegmentsUsed;
2124 segmentIdx++) {
2125 segment = &region->segment[segmentIdx];
2126
2127 if (memMap->dir == DMA_TO_DEVICE) {
2128 srcPhysAddr = segment->physAddr;
2129 dstPhysAddr = devPhysAddr;
2130 } else {
2131 srcPhysAddr = devPhysAddr;
2132 dstPhysAddr = segment->physAddr;
2133 }
2134
2135 rc =
2136 dma_calculate_descriptor_count(dev, srcPhysAddr,
2137 dstPhysAddr,
2138 segment->
2139 numBytes);
2140 if (rc < 0) {
2141 printk(KERN_ERR
2142 "%s: dma_calculate_descriptor_count failed: %d\n",
2143 __func__, rc);
2144 goto out;
2145 }
2146 numDescriptors += rc;
2147 }
2148 }
2149
2150 /* Adjust the size of the ring, if it isn't big enough */
2151
2152 if (numDescriptors > devAttr->ring.descriptorsAllocated) {
2153 dma_free_descriptor_ring(&devAttr->ring);
2154 rc =
2155 dma_alloc_descriptor_ring(&devAttr->ring,
2156 numDescriptors);
2157 if (rc < 0) {
2158 printk(KERN_ERR
2159 "%s: dma_alloc_descriptor_ring failed: %d\n",
2160 __func__, rc);
2161 goto out;
2162 }
2163 } else {
2164 rc =
2165 dma_init_descriptor_ring(&devAttr->ring,
2166 numDescriptors);
2167 if (rc < 0) {
2168 printk(KERN_ERR
2169 "%s: dma_init_descriptor_ring failed: %d\n",
2170 __func__, rc);
2171 goto out;
2172 }
2173 }
2174
2175 /* Populate the descriptors */
2176
2177 for (regionIdx = 0; regionIdx < memMap->numRegionsUsed; regionIdx++) {
2178 region = &memMap->region[regionIdx];
2179
2180 for (segmentIdx = 0; segmentIdx < region->numSegmentsUsed;
2181 segmentIdx++) {
2182 segment = &region->segment[segmentIdx];
2183
2184 if (memMap->dir == DMA_TO_DEVICE) {
2185 srcPhysAddr = segment->physAddr;
2186 dstPhysAddr = devPhysAddr;
2187 } else {
2188 srcPhysAddr = devPhysAddr;
2189 dstPhysAddr = segment->physAddr;
2190 }
2191
2192 rc =
2193 dma_add_descriptors(&devAttr->ring, dev,
2194 srcPhysAddr, dstPhysAddr,
2195 segment->numBytes);
2196 if (rc < 0) {
2197 printk(KERN_ERR
2198 "%s: dma_add_descriptors failed: %d\n",
2199 __func__, rc);
2200 goto out;
2201 }
2202 }
2203 }
2204
2205 rc = 0;
2206
2207 out:
2208
2209 up(&memMap->lock);
2210 return rc;
2211 }
2212
2213 EXPORT_SYMBOL(dma_map_create_descriptor_ring);
2214
2215 /****************************************************************************/
2216 /**
2217 * Maps in a memory region such that it can be used for performing a DMA.
2218 *
2219 * @return
2220 */
2221 /****************************************************************************/
2222
2223 int dma_unmap(DMA_MemMap_t *memMap, /* Stores state information about the map */
2224 int dirtied /* non-zero if any of the pages were modified */
2225 ) {
2226
2227 int rc = 0;
2228 int regionIdx;
2229 int segmentIdx;
2230 DMA_Region_t *region;
2231 DMA_Segment_t *segment;
2232
2233 down(&memMap->lock);
2234
2235 for (regionIdx = 0; regionIdx < memMap->numRegionsUsed; regionIdx++) {
2236 region = &memMap->region[regionIdx];
2237
2238 for (segmentIdx = 0; segmentIdx < region->numSegmentsUsed;
2239 segmentIdx++) {
2240 segment = &region->segment[segmentIdx];
2241
2242 switch (region->memType) {
2243 case DMA_MEM_TYPE_VMALLOC:
2244 {
2245 printk(KERN_ERR
2246 "%s: vmalloc'd pages are not yet supported\n",
2247 __func__);
2248 rc = -EINVAL;
2249 goto out;
2250 }
2251
2252 case DMA_MEM_TYPE_KMALLOC:
2253 {
2254 #if ALLOW_MAP_OF_KMALLOC_MEMORY
2255 dma_unmap_single(NULL,
2256 segment->physAddr,
2257 segment->numBytes,
2258 memMap->dir);
2259 #endif
2260 break;
2261 }
2262
2263 case DMA_MEM_TYPE_DMA:
2264 {
2265 dma_sync_single_for_cpu(NULL,
2266 segment->
2267 physAddr,
2268 segment->
2269 numBytes,
2270 memMap->dir);
2271 break;
2272 }
2273
2274 case DMA_MEM_TYPE_USER:
2275 {
2276 /* Nothing to do here. */
2277
2278 break;
2279 }
2280
2281 default:
2282 {
2283 printk(KERN_ERR
2284 "%s: Unsupported memory type: %d\n",
2285 __func__, region->memType);
2286 rc = -EINVAL;
2287 goto out;
2288 }
2289 }
2290
2291 segment->virtAddr = NULL;
2292 segment->physAddr = 0;
2293 segment->numBytes = 0;
2294 }
2295
2296 if (region->numLockedPages > 0) {
2297 int pageIdx;
2298
2299 /* Some user pages were locked. We need to go and unlock them now. */
2300
2301 for (pageIdx = 0; pageIdx < region->numLockedPages;
2302 pageIdx++) {
2303 struct page *page =
2304 region->lockedPages[pageIdx];
2305
2306 if (memMap->dir == DMA_FROM_DEVICE) {
2307 SetPageDirty(page);
2308 }
2309 page_cache_release(page);
2310 }
2311 kfree(region->lockedPages);
2312 region->numLockedPages = 0;
2313 region->lockedPages = NULL;
2314 }
2315
2316 region->memType = DMA_MEM_TYPE_NONE;
2317 region->virtAddr = NULL;
2318 region->numBytes = 0;
2319 region->numSegmentsUsed = 0;
2320 }
2321 memMap->userTask = NULL;
2322 memMap->numRegionsUsed = 0;
2323 memMap->inUse = 0;
2324
2325 out:
2326 up(&memMap->lock);
2327
2328 return rc;
2329 }
2330
2331 EXPORT_SYMBOL(dma_unmap);