kernel/device_manager/dma_resources.cpp

58 	vec.length = size;
86 			i, fVecs[i].base, fVecs[i].length);
289 	generic_addr_t& length)
291 	if (length > fRestrictions.max_segment_size)
292 		length = fRestrictions.max_segment_size;
296 				!= (base + (length - 1)) / fRestrictions.boundary) {
297 			length = (baseBoundary + 1) * fRestrictions.boundary - base;
310 		generic_size_t length = vec.length;
313 		if (length <= toCut) {
315 			toCut -= length;
318 				bounceLeft += length;
319 				physicalBounceBuffer -= length;
322 			vec.length -= toCut;
336 /*!	Adds \a length bytes from the bounce buffer to the DMABuffer \a buffer.
337 	Takes care of boundary, and segment restrictions. \a length must be aligned.
349 	generic_size_t length, bool fixedLength)
351 	if (bounceLeft < length) {
355 		length = bounceLeft;
365 		generic_size_t vecLength = vec.length;
368 			vecLength += length;
371 			generic_size_t lengthDiff = vecLength - vec.length;
372 			length -= lengthDiff;
378 			vec.length = vecLength;
382 	while (length > 0) {
388 		generic_addr_t vecLength = length;
397 		length -= vecLength;
454 				generic_size_t size = vec.length - vecOffset;
467 					vecs[segmentCount].length = entry.size;
495 			i, vecs[vecIndex + i].base, vecs[vecIndex + i].length);
519 		generic_size_t length;
522 			length = fBlockSize;
524 			length = (partialBegin + fRestrictions.alignment - 1)
529 				length, true) == 0) {
530 			TRACE("  adding partial begin failed, length %lu!\n", length);
534 		dmaLength += length;
536 		generic_size_t transferred = length - partialBegin;
545 		TRACE("  partial begin, using bounce buffer: offset: %" B_PRIdOFF ", length: "
546 			"%lu\n", offset, length);
555 		if (vec.length <= vecOffset) {
556 			vecOffset -= vec.length;
562 		generic_size_t maxLength = vec.length - vecOffset;
565 		generic_size_t length = maxLength;
569 		if (dmaLength + length > fRestrictions.max_transfer_size) {
570 			length = fRestrictions.max_transfer_size - dmaLength;
571 			TRACE("  vec %" B_PRIu32 ": restricting length to %lu due to transfer size "
572 				"limit\n", i, length);
574 		_RestrictBoundaryAndSegmentSize(base, length);
585 			useBounceBufferSize = length;
592 			useBounceBufferSize = length;
593 		else if (base + length > fRestrictions.high_address)
594 			length = fRestrictions.high_address - base;
596 		// Align length as well
598 			length &= ~(fRestrictions.alignment - 1);
600 		// If length is 0, use bounce buffer for complete vec.
601 		if (length == 0) {
602 			length = maxLength;
603 			useBounceBufferSize = length;
604 			TRACE("  vec %" B_PRIu32 ": 0 length, using bounce buffer: %lu\n", i,
613 			length = _AddBounceBuffer(*dmaBuffer, physicalBounceBuffer,
615 			if (length == 0) {
621 			TRACE("  vec %" B_PRIu32 ": final bounce length: %lu\n", i, length);
623 			TRACE("  vec %" B_PRIu32 ": final length restriction: %lu\n", i, length);
624 			dmaBuffer->AddVec(base, length);
627 		dmaLength += length;
628 		vecOffset += length;
629 		transferLeft -= min_c(length, transferLeft);
639 		// If the transfer length is block aligned and we're writing past the
654 			if (dmaVec.length < fBlockSize)
678 	// If total length not block aligned, use bounce buffer for padding (read
682 			generic_size_t length
685 		// If total length > max transfer size, segment count > max segment
689 		if (length > fRestrictions.max_transfer_size
691 			|| bounceLeft < length - dmaLength) {
692 			// cut the part of dma length
693 			TRACE("  can't align length due to max transfer size, segment "
701 				// bounce buffer for as much as possible of the total length.
716 				length - dmaLength);
717 			length -= dmaLength;
718 			length = _AddBounceBuffer(*dmaBuffer, physicalBounceBuffer,
719 				bounceLeft, length, true);
720 			if (length == 0)
722 			dmaLength += length;