dmabuf.c

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	dmap->user_counter += l;
	dmap->flags |= DMA_DIRTY;

	if (dmap->byte_counter >= dmap->max_byte_counter) {
		/* Wrap the byte counters */
		long decr = dmap->byte_counter;
		dmap->byte_counter = (dmap->byte_counter % dmap->bytes_in_use);
		decr -= dmap->byte_counter;
		dmap->user_counter -= decr;
	}
	end_ptr = (dmap->user_counter / dmap->fragment_size) * dmap->fragment_size;

	p = (dmap->user_counter - 1) % dmap->bytes_in_use;
	dmap->neutral_byte = dmap->raw_buf[p];

	/* Update the fragment based bookkeeping too */
	while (ptr < end_ptr) {
		dmap->counts[dmap->qtail] = dmap->fragment_size;
		dmap->qtail = (dmap->qtail + 1) % dmap->nbufs;
		dmap->qlen++;
		ptr += dmap->fragment_size;
	}

	dmap->counts[dmap->qtail] = dmap->user_counter - ptr;

	/*
	 *	Let the low level driver to perform some postprocessing to
	 *	the written data.
	 */
	if (adev->d->postprocess_write)
		adev->d->postprocess_write(dev);

	if (!(dmap->flags & DMA_ACTIVE))
		if (dmap->qlen > 1 || (dmap->qlen > 0 && (post || dmap->qlen >= dmap->nbufs - 1)))
			DMAbuf_launch_output(dev, dmap);
	return 0;
}

int DMAbuf_start_dma(int dev, unsigned long physaddr, int count, int dma_mode)
{
	struct audio_operations *adev = audio_devs[dev];
	struct dma_buffparms *dmap = (dma_mode == DMA_MODE_WRITE) ? adev->dmap_out : adev->dmap_in;

	if (dmap->raw_buf == NULL) {
		printk(KERN_ERR "sound: DMA buffer(1) == NULL\n");
		printk("Device %d, chn=%s\n", dev, (dmap == adev->dmap_out) ? "out" : "in");
		return 0;
	}
	if (dmap->dma < 0)
		return 0;
	sound_start_dma(dmap, physaddr, count, dma_mode);
	return count;
}

static int local_start_dma(struct audio_operations *adev, unsigned long physaddr, int count, int dma_mode)
{
	struct dma_buffparms *dmap = (dma_mode == DMA_MODE_WRITE) ? adev->dmap_out : adev->dmap_in;

	if (dmap->raw_buf == NULL) {
		printk(KERN_ERR "sound: DMA buffer(2) == NULL\n");
		printk(KERN_ERR "Device %s, chn=%s\n", adev->name, (dmap == adev->dmap_out) ? "out" : "in");
		return 0;
	}
	if (dmap->flags & DMA_NODMA)
		return 1;
	if (dmap->dma < 0)
		return 0;
	sound_start_dma(dmap, dmap->raw_buf_phys, dmap->bytes_in_use, dma_mode | DMA_AUTOINIT);
	dmap->flags |= DMA_STARTED;
	return count;
}

static void finish_output_interrupt(int dev, struct dma_buffparms *dmap)
{
	struct audio_operations *adev = audio_devs[dev];

	if (dmap->audio_callback != NULL)
		dmap->audio_callback(dev, dmap->callback_parm);
	wake_up(&adev->out_sleeper);
	wake_up(&adev->poll_sleeper);
}

static void do_outputintr(int dev, int dummy)
{
	struct audio_operations *adev = audio_devs[dev];
	unsigned long flags;
	struct dma_buffparms *dmap = adev->dmap_out;
	int this_fragment;

	if (dmap->raw_buf == NULL) {
		printk(KERN_ERR "Sound: Error. Audio interrupt (%d) after freeing buffers.\n", dev);
		return;
	}
	if (dmap->mapping_flags & DMA_MAP_MAPPED) {	/* Virtual memory mapped access */
		/* mmapped access */
		dmap->qhead = (dmap->qhead + 1) % dmap->nbufs;
		if (dmap->qhead == 0) {	    /* Wrapped */
			dmap->byte_counter += dmap->bytes_in_use;
			if (dmap->byte_counter >= dmap->max_byte_counter) {	/* Overflow */
				long decr = dmap->byte_counter;
				dmap->byte_counter = (dmap->byte_counter % dmap->bytes_in_use);
				decr -= dmap->byte_counter;
				dmap->user_counter -= decr;
			}
		}
		dmap->qlen++;	/* Yes increment it (don't decrement) */
		if (!(adev->flags & DMA_AUTOMODE))
			dmap->flags &= ~DMA_ACTIVE;
		dmap->counts[dmap->qhead] = dmap->fragment_size;
		DMAbuf_launch_output(dev, dmap);
		finish_output_interrupt(dev, dmap);
		return;
	}
	save_flags(flags);
	cli();

	dmap->qlen--;
	this_fragment = dmap->qhead;
	dmap->qhead = (dmap->qhead + 1) % dmap->nbufs;

	if (dmap->qhead == 0) {	/* Wrapped */
		dmap->byte_counter += dmap->bytes_in_use;
		if (dmap->byte_counter >= dmap->max_byte_counter) {	/* Overflow */
			long decr = dmap->byte_counter;
			dmap->byte_counter = (dmap->byte_counter % dmap->bytes_in_use);
			decr -= dmap->byte_counter;
			dmap->user_counter -= decr;
		}
	}
	if (!(adev->flags & DMA_AUTOMODE))
		dmap->flags &= ~DMA_ACTIVE;
		
	/*
	 *	This is  dmap->qlen <= 0 except when closing when
	 *	dmap->qlen < 0
	 */
	 
	while (dmap->qlen <= -dmap->closing) {
		dmap->underrun_count++;
		dmap->qlen++;
		if ((dmap->flags & DMA_DIRTY) && dmap->applic_profile != APF_CPUINTENS) {
			dmap->flags &= ~DMA_DIRTY;
			memset(adev->dmap_out->raw_buf, adev->dmap_out->neutral_byte,
			       adev->dmap_out->buffsize);
		}
		dmap->user_counter += dmap->fragment_size;
		dmap->qtail = (dmap->qtail + 1) % dmap->nbufs;
	}
	if (dmap->qlen > 0)
		DMAbuf_launch_output(dev, dmap);
	restore_flags(flags);
	finish_output_interrupt(dev, dmap);
}

void DMAbuf_outputintr(int dev, int notify_only)
{
	struct audio_operations *adev = audio_devs[dev];
	unsigned long flags;
	struct dma_buffparms *dmap = adev->dmap_out;

	save_flags(flags);
	cli();
	if (!(dmap->flags & DMA_NODMA)) {
		int chan = dmap->dma, pos, n;
		unsigned long f;
		
		f=claim_dma_lock();
		
		if(!isa_dma_bridge_buggy)
			disable_dma(dmap->dma);
		clear_dma_ff(chan);
		pos = dmap->bytes_in_use - get_dma_residue(chan);
		if(!isa_dma_bridge_buggy)
			enable_dma(dmap->dma);
		release_dma_lock(f);
		
		pos = pos / dmap->fragment_size;	/* Actual qhead */
		if (pos < 0 || pos >= dmap->nbufs)
			pos = 0;
		n = 0;
		while (dmap->qhead != pos && n++ < dmap->nbufs)
			do_outputintr(dev, notify_only);
	}
	else
		do_outputintr(dev, notify_only);
	restore_flags(flags);
}

static void do_inputintr(int dev)
{
	struct audio_operations *adev = audio_devs[dev];
	struct dma_buffparms *dmap = adev->dmap_in;

	if (dmap->raw_buf == NULL) {
		printk(KERN_ERR "Sound: Fatal error. Audio interrupt after freeing buffers.\n");
		return;
	}
	if (dmap->mapping_flags & DMA_MAP_MAPPED) {
		dmap->qtail = (dmap->qtail + 1) % dmap->nbufs;
		if (dmap->qtail == 0) {		/* Wrapped */
			dmap->byte_counter += dmap->bytes_in_use;
			if (dmap->byte_counter >= dmap->max_byte_counter) {	/* Overflow */
				long decr = dmap->byte_counter;
				dmap->byte_counter = (dmap->byte_counter % dmap->bytes_in_use) + dmap->bytes_in_use;
				decr -= dmap->byte_counter;
				dmap->user_counter -= decr;
			}
		}
		dmap->qlen++;

		if (!(adev->flags & DMA_AUTOMODE)) {
			if (dmap->needs_reorg)
				reorganize_buffers(dev, dmap, 0);
			local_start_dma(adev, dmap->raw_buf_phys, dmap->bytes_in_use,DMA_MODE_READ);
			adev->d->start_input(dev, dmap->raw_buf_phys + dmap->qtail * dmap->fragment_size,
					     dmap->fragment_size, 1);
			if (adev->d->trigger)
				adev->d->trigger(dev, adev->enable_bits * adev->go);
		}
		dmap->flags |= DMA_ACTIVE;
	} else if (dmap->qlen >= (dmap->nbufs - 1)) {
		printk(KERN_WARNING "Sound: Recording overrun\n");
		dmap->underrun_count++;

		/* Just throw away the oldest fragment but keep the engine running */
		dmap->qhead = (dmap->qhead + 1) % dmap->nbufs;
		dmap->qtail = (dmap->qtail + 1) % dmap->nbufs;
	} else if (dmap->qlen >= 0 && dmap->qlen < dmap->nbufs) {
		dmap->qlen++;
		dmap->qtail = (dmap->qtail + 1) % dmap->nbufs;
		if (dmap->qtail == 0) {		/* Wrapped */
			dmap->byte_counter += dmap->bytes_in_use;
			if (dmap->byte_counter >= dmap->max_byte_counter) {	/* Overflow */
				long decr = dmap->byte_counter;
				dmap->byte_counter = (dmap->byte_counter % dmap->bytes_in_use) + dmap->bytes_in_use;
				decr -= dmap->byte_counter;
				dmap->user_counter -= decr;
			}
		}
	}
	if (!(adev->flags & DMA_AUTOMODE) || (dmap->flags & DMA_NODMA)) {
		local_start_dma(adev, dmap->raw_buf_phys, dmap->bytes_in_use, DMA_MODE_READ);
		adev->d->start_input(dev, dmap->raw_buf_phys + dmap->qtail * dmap->fragment_size, dmap->fragment_size, 1);
		if (adev->d->trigger)
			adev->d->trigger(dev,adev->enable_bits * adev->go);
	}
	dmap->flags |= DMA_ACTIVE;
	if (dmap->qlen > 0)
	{
		wake_up(&adev->in_sleeper);
		wake_up(&adev->poll_sleeper);
	}
}

void DMAbuf_inputintr(int dev)
{
	struct audio_operations *adev = audio_devs[dev];
	struct dma_buffparms *dmap = adev->dmap_in;
	unsigned long flags;

	save_flags(flags);
	cli();

	if (!(dmap->flags & DMA_NODMA)) {
		int chan = dmap->dma, pos, n;
		unsigned long f;
		
		f=claim_dma_lock();
		if(!isa_dma_bridge_buggy)
			disable_dma(dmap->dma);
		clear_dma_ff(chan);
		pos = dmap->bytes_in_use - get_dma_residue(chan);
		if(!isa_dma_bridge_buggy)
			enable_dma(dmap->dma);
		release_dma_lock(f);

		pos = pos / dmap->fragment_size;	/* Actual qhead */
		if (pos < 0 || pos >= dmap->nbufs)
			pos = 0;

		n = 0;
		while (dmap->qtail != pos && ++n < dmap->nbufs)
			do_inputintr(dev);
	} else
		do_inputintr(dev);
	restore_flags(flags);
}

int DMAbuf_open_dma(int dev)
{
	/*
	 *    NOTE!  This routine opens only the primary DMA channel (output).
	 */
	struct audio_operations *adev = audio_devs[dev];
	int err;

	if ((err = open_dmap(adev, OPEN_READWRITE, adev->dmap_out)) < 0)
		return -EBUSY;
	dma_init_buffers(adev->dmap_out);
	adev->dmap_out->flags |= DMA_ALLOC_DONE;
	adev->dmap_out->fragment_size = adev->dmap_out->buffsize;

	if (adev->dmap_out->dma >= 0) {
		unsigned long flags;

		flags=claim_dma_lock();
		clear_dma_ff(adev->dmap_out->dma);
		disable_dma(adev->dmap_out->dma);
		release_dma_lock(flags);
	}
	return 0;
}

void DMAbuf_close_dma(int dev)
{
	close_dmap(audio_devs[dev], audio_devs[dev]->dmap_out);
}

void DMAbuf_init(int dev, int dma1, int dma2)
{
	struct audio_operations *adev = audio_devs[dev];
	/*
	 * NOTE! This routine could be called several times.
	 */

	/* drag in audio_syms.o */
	{
		extern char audio_syms_symbol;
		audio_syms_symbol = 0;
	}

	if (adev && adev->dmap_out == NULL) {
		if (adev->d == NULL)
			panic("OSS: audio_devs[%d]->d == NULL\n", dev);

		if (adev->parent_dev) {	 /* Use DMA map of the parent dev */
			int parent = adev->parent_dev - 1;
			adev->dmap_out = audio_devs[parent]->dmap_out;
			adev->dmap_in = audio_devs[parent]->dmap_in;
		} else {
			adev->dmap_out = adev->dmap_in = &adev->dmaps[0];
			adev->dmap_out->dma = dma1;
			if (adev->flags & DMA_DUPLEX) {
				adev->dmap_in = &adev->dmaps[1];
				adev->dmap_in->dma = dma2;
			}
		}
		/* Persistent DMA buffers allocated here */
		if (sound_dmap_flag == DMAP_KEEP_ON_CLOSE) {
			if (adev->dmap_in->raw_buf == NULL)
				sound_alloc_dmap(adev->dmap_in);
			if (adev->dmap_out->raw_buf == NULL)
				sound_alloc_dmap(adev->dmap_out);
		}
	}
}

/* No kernel lock - DMAbuf_activate_recording protected by global cli/sti */
static unsigned int poll_input(struct file * file, int dev, poll_table *wait)
{
	struct audio_operations *adev = audio_devs[dev];
	struct dma_buffparms *dmap = adev->dmap_in;

	if (!(adev->open_mode & OPEN_READ))
		return 0;
	if (dmap->mapping_flags & DMA_MAP_MAPPED) {
		if (dmap->qlen)
			return POLLIN | POLLRDNORM;
		return 0;
	}
	if (dmap->dma_mode != DMODE_INPUT) {
		if (dmap->dma_mode == DMODE_NONE &&
		    adev->enable_bits & PCM_ENABLE_INPUT &&
		    !dmap->qlen && adev->go) {
			unsigned long flags;
			
			save_flags(flags);
			cli();
			DMAbuf_activate_recording(dev, dmap);
			restore_flags(flags);
		}
		return 0;
	}
	if (!dmap->qlen)
		return 0;
	return POLLIN | POLLRDNORM;
}

static unsigned int poll_output(struct file * file, int dev, poll_table *wait)
{
	struct audio_operations *adev = audio_devs[dev];
	struct dma_buffparms *dmap = adev->dmap_out;
	
	if (!(adev->open_mode & OPEN_WRITE))
		return 0;
	if (dmap->mapping_flags & DMA_MAP_MAPPED) {
		if (dmap->qlen)
			return POLLOUT | POLLWRNORM;
		return 0;
	}
	if (dmap->dma_mode == DMODE_INPUT)
		return 0;
	if (dmap->dma_mode == DMODE_NONE)
		return POLLOUT | POLLWRNORM;
	if (!DMAbuf_space_in_queue(dev))
		return 0;
	return POLLOUT | POLLWRNORM;
}

unsigned int DMAbuf_poll(struct file * file, int dev, poll_table *wait)
{
	struct audio_operations *adev = audio_devs[dev];
	poll_wait(file, &adev->poll_sleeper, wait);
	return poll_input(file, dev, wait) | poll_output(file, dev, wait);
}

void DMAbuf_deinit(int dev)
{
	struct audio_operations *adev = audio_devs[dev];
	/* This routine is called when driver is being unloaded */
	if (!adev)
		return;

	/* Persistent DMA buffers deallocated here */
	if (sound_dmap_flag == DMAP_KEEP_ON_CLOSE) {
		sound_free_dmap(adev->dmap_out);
		if (adev->flags & DMA_DUPLEX)
			sound_free_dmap(adev->dmap_in);
	}
}