[deliverable/linux.git] / drivers / firewire / fw-iso.c

/*
 * Isochronous I/O functionality:
 *   - Isochronous DMA context management
 *   - Isochronous bus resource management (channels, bandwidth), client side
 *
 * Copyright (C) 2006 Kristian Hoegsberg <krh@bitplanet.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include <linux/dma-mapping.h>
#include <linux/errno.h>
#include <linux/firewire-constants.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/spinlock.h>
#include <linux/vmalloc.h>

#include "fw-topology.h"
#include "fw-transaction.h"

/*
 * Isochronous DMA context management
 */

int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card,
		       int page_count, enum dma_data_direction direction)
{
	int i, j;
	dma_addr_t address;

	buffer->page_count = page_count;
	buffer->direction = direction;

	buffer->pages = kmalloc(page_count * sizeof(buffer->pages[0]),
				GFP_KERNEL);
	if (buffer->pages == NULL)
		goto out;

	for (i = 0; i < buffer->page_count; i++) {
		buffer->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO);
		if (buffer->pages[i] == NULL)
			goto out_pages;

		address = dma_map_page(card->device, buffer->pages[i],
				       0, PAGE_SIZE, direction);
		if (dma_mapping_error(card->device, address)) {
			__free_page(buffer->pages[i]);
			goto out_pages;
		}
		set_page_private(buffer->pages[i], address);
	}

	return 0;

 out_pages:
	for (j = 0; j < i; j++) {
		address = page_private(buffer->pages[j]);
		dma_unmap_page(card->device, address,
			       PAGE_SIZE, DMA_TO_DEVICE);
		__free_page(buffer->pages[j]);
	}
	kfree(buffer->pages);
 out:
	buffer->pages = NULL;
	return -ENOMEM;
}

int fw_iso_buffer_map(struct fw_iso_buffer *buffer, struct vm_area_struct *vma)
{
	unsigned long uaddr;
	int i, ret;

	uaddr = vma->vm_start;
	for (i = 0; i < buffer->page_count; i++) {
		ret = vm_insert_page(vma, uaddr, buffer->pages[i]);
		if (ret)
			return ret;
		uaddr += PAGE_SIZE;
	}

	return 0;
}

void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer,
			   struct fw_card *card)
{
	int i;
	dma_addr_t address;

	for (i = 0; i < buffer->page_count; i++) {
		address = page_private(buffer->pages[i]);
		dma_unmap_page(card->device, address,
			       PAGE_SIZE, DMA_TO_DEVICE);
		__free_page(buffer->pages[i]);
	}

	kfree(buffer->pages);
	buffer->pages = NULL;
}

struct fw_iso_context *fw_iso_context_create(struct fw_card *card,
		int type, int channel, int speed, size_t header_size,
		fw_iso_callback_t callback, void *callback_data)
{
	struct fw_iso_context *ctx;

	ctx = card->driver->allocate_iso_context(card,
						 type, channel, header_size);
	if (IS_ERR(ctx))
		return ctx;

	ctx->card = card;
	ctx->type = type;
	ctx->channel = channel;
	ctx->speed = speed;
	ctx->header_size = header_size;
	ctx->callback = callback;
	ctx->callback_data = callback_data;

	return ctx;
}

void fw_iso_context_destroy(struct fw_iso_context *ctx)
{
	struct fw_card *card = ctx->card;

	card->driver->free_iso_context(ctx);
}

int fw_iso_context_start(struct fw_iso_context *ctx,
			 int cycle, int sync, int tags)
{
	return ctx->card->driver->start_iso(ctx, cycle, sync, tags);
}

int fw_iso_context_queue(struct fw_iso_context *ctx,
			 struct fw_iso_packet *packet,
			 struct fw_iso_buffer *buffer,
			 unsigned long payload)
{
	struct fw_card *card = ctx->card;

	return card->driver->queue_iso(ctx, packet, buffer, payload);
}

int fw_iso_context_stop(struct fw_iso_context *ctx)
{
	return ctx->card->driver->stop_iso(ctx);
}

/*
 * Isochronous bus resource management (channels, bandwidth), client side
 */

static int manage_bandwidth(struct fw_card *card, int irm_id, int generation,
			    int bandwidth, bool allocate)
{
	__be32 data[2];
	int try, new, old = allocate ? BANDWIDTH_AVAILABLE_INITIAL : 0;

	/*
	 * On a 1394a IRM with low contention, try < 1 is enough.
	 * On a 1394-1995 IRM, we need at least try < 2.
	 * Let's just do try < 5.
	 */
	for (try = 0; try < 5; try++) {
		new = allocate ? old - bandwidth : old + bandwidth;
		if (new < 0 || new > BANDWIDTH_AVAILABLE_INITIAL)
			break;

		data[0] = cpu_to_be32(old);
		data[1] = cpu_to_be32(new);
		switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
				irm_id, generation, SCODE_100,
				CSR_REGISTER_BASE + CSR_BANDWIDTH_AVAILABLE,
				data, sizeof(data))) {
		case RCODE_GENERATION:
			/* A generation change frees all bandwidth. */
			return allocate ? -EAGAIN : bandwidth;

		case RCODE_COMPLETE:
			if (be32_to_cpup(data) == old)
				return bandwidth;

			old = be32_to_cpup(data);
			/* Fall through. */
		}
	}

	return -EIO;
}

static int manage_channel(struct fw_card *card, int irm_id, int generation,
			  __be32 channels_mask, u64 offset, bool allocate)
{
	__be32 data[2], c, old = allocate ? cpu_to_be32(~0) : 0;
	int i, retry = 5;

	for (i = 0; i < 32; i++) {
		c = cpu_to_be32(1 << (31 - i));
		if (!(channels_mask & c))
			continue;

		if (allocate == !(old & c))
			continue;

		data[0] = old;
		data[1] = old ^ c;
		switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
					   irm_id, generation, SCODE_100,
					   offset, data, sizeof(data))) {
		case RCODE_GENERATION:
			/* A generation change frees all channels. */
			return allocate ? -EAGAIN : i;

		case RCODE_COMPLETE:
			if (data[0] == old)
				return i;

			old = data[0];

			/* Is the IRM 1394a-2000 compliant? */
			if ((data[0] & c) != (data[1] & c))
				continue;

			/* 1394-1995 IRM, fall through to retry. */
		default:
			if (retry--)
				i--;
		}
	}

	return -EIO;
}

static void deallocate_channel(struct fw_card *card, int irm_id,
			       int generation, int channel)
{
	__be32 mask;
	u64 offset;

	mask = channel < 32 ? cpu_to_be32(1 << (31 - channel)) :
			      cpu_to_be32(1 << (63 - channel));
	offset = channel < 32 ? CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI :
				CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO;

	manage_channel(card, irm_id, generation, mask, offset, false);
}

/**
 * fw_iso_resource_manage - Allocate or deallocate a channel and/or bandwidth
 *
 * In parameters: card, generation, channels_mask, bandwidth, allocate
 * Out parameters: channel, bandwidth
 * This function blocks (sleeps) during communication with the IRM.
 * Allocates or deallocates at most one channel out of channels_mask.
 *
 * Returns channel < 0 if no channel was allocated or deallocated.
 * Returns bandwidth = 0 if no bandwidth was allocated or deallocated.
 *
 * If generation is stale, deallocations succeed but allocations fail with
 * channel = -EAGAIN.
 *
 * If channel (de)allocation fails, bandwidth (de)allocation fails too.
 * If bandwidth allocation fails, no channel will be allocated either.
 * If bandwidth deallocation fails, channel deallocation may still have been
 * successful.
 */
void fw_iso_resource_manage(struct fw_card *card, int generation,
			    u64 channels_mask, int *channel, int *bandwidth,
			    bool allocate)
{
	__be32 channels_hi = cpu_to_be32(channels_mask >> 32);
	__be32 channels_lo = cpu_to_be32(channels_mask);
	int irm_id, ret, c = -EINVAL;

	spin_lock_irq(&card->lock);
	irm_id = card->irm_node->node_id;
	spin_unlock_irq(&card->lock);

	if (channels_hi)
		c = manage_channel(card, irm_id, generation, channels_hi,
		    CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI, allocate);
	if (channels_lo && c < 0) {
		c = manage_channel(card, irm_id, generation, channels_lo,
		    CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO, allocate);
		if (c >= 0)
			c += 32;
	}
	*channel = c;

	if (channels_mask != 0 && c < 0)
		*bandwidth = 0;

	if (*bandwidth == 0)
		return;

	ret = manage_bandwidth(card, irm_id, generation, *bandwidth, allocate);
	if (ret < 0)
		*bandwidth = 0;

	if (ret < 0 && c >= 0 && allocate) {
		deallocate_channel(card, irm_id, generation, c);
		*channel = ret;
	}
}
Commit	Line	Data
c781c06d	1	/*
b1bda4cd JFSR	2	* Isochronous I/O functionality:
	3	* - Isochronous DMA context management
	4	* - Isochronous bus resource management (channels, bandwidth), client side
3038e353	5	*
3038e353 KH	6	* Copyright (C) 2006 Kristian Hoegsberg <krh@bitplanet.net>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2 of the License, or
	11	* (at your option) any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software Foundation,
	20	* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	21	*/
	22
3038e353	23	#include <linux/dma-mapping.h>
b1bda4cd JFSR	24	#include <linux/errno.h>
	25	#include <linux/firewire-constants.h>
	26	#include <linux/kernel.h>
3038e353	27	#include <linux/mm.h>
b1bda4cd JFSR	28	#include <linux/spinlock.h>
b1bda4cd JFSR	29	#include <linux/vmalloc.h>
3038e353	30
3038e353	31	#include "fw-topology.h"
b1bda4cd JFSR	32	#include "fw-transaction.h"
	33
	34	/*
	35	* Isochronous DMA context management
	36	*/
3038e353	37
53dca511 SR	38	int fw_iso_buffer_init(struct fw_iso_buffer buffer, struct fw_card card,
53dca511 SR	39	int page_count, enum dma_data_direction direction)
3038e353	40	{
2dbd7d7e	41	int i, j;
9aad8125 KH	42	dma_addr_t address;
	43
	44	buffer->page_count = page_count;
	45	buffer->direction = direction;
	46
	47	buffer->pages = kmalloc(page_count * sizeof(buffer->pages[0]),
	48	GFP_KERNEL);
	49	if (buffer->pages == NULL)
	50	goto out;
	51
	52	for (i = 0; i < buffer->page_count; i++) {
68be3fa1	53	buffer->pages[i] = alloc_page(GFP_KERNEL \| GFP_DMA32 \| __GFP_ZERO);
9aad8125 KH	54	if (buffer->pages[i] == NULL)
9aad8125 KH	55	goto out_pages;
373b2edd	56
9aad8125 KH	57	address = dma_map_page(card->device, buffer->pages[i],
9aad8125 KH	58	0, PAGE_SIZE, direction);
8d8bb39b	59	if (dma_mapping_error(card->device, address)) {
9aad8125 KH	60	__free_page(buffer->pages[i]);
	61	goto out_pages;
	62	}
	63	set_page_private(buffer->pages[i], address);
3038e353 KH	64	}
	65
	66	return 0;
82eff9db	67
9aad8125 KH	68	out_pages:
	69	for (j = 0; j < i; j++) {
	70	address = page_private(buffer->pages[j]);
	71	dma_unmap_page(card->device, address,
82eff9db	72	PAGE_SIZE, DMA_TO_DEVICE);
9aad8125 KH	73	__free_page(buffer->pages[j]);
	74	}
	75	kfree(buffer->pages);
	76	out:
	77	buffer->pages = NULL;
2dbd7d7e	78	return -ENOMEM;
9aad8125 KH	79	}
	80
	81	int fw_iso_buffer_map(struct fw_iso_buffer buffer, struct vm_area_struct vma)
	82	{
	83	unsigned long uaddr;
2dbd7d7e	84	int i, ret;
9aad8125 KH	85
	86	uaddr = vma->vm_start;
	87	for (i = 0; i < buffer->page_count; i++) {
2dbd7d7e SR	88	ret = vm_insert_page(vma, uaddr, buffer->pages[i]);
	89	if (ret)
	90	return ret;
9aad8125 KH	91	uaddr += PAGE_SIZE;
	92	}
	93
	94	return 0;
3038e353 KH	95	}
3038e353 KH	96
9aad8125 KH	97	void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer,
9aad8125 KH	98	struct fw_card *card)
3038e353 KH	99	{
3038e353 KH	100	int i;
9aad8125	101	dma_addr_t address;
3038e353	102
9aad8125 KH	103	for (i = 0; i < buffer->page_count; i++) {
	104	address = page_private(buffer->pages[i]);
	105	dma_unmap_page(card->device, address,
3038e353	106	PAGE_SIZE, DMA_TO_DEVICE);
9aad8125 KH	107	__free_page(buffer->pages[i]);
9aad8125 KH	108	}
3038e353	109
9aad8125 KH	110	kfree(buffer->pages);
9aad8125 KH	111	buffer->pages = NULL;
3038e353 KH	112	}
3038e353 KH	113
53dca511 SR	114	struct fw_iso_context fw_iso_context_create(struct fw_card card,
	115	int type, int channel, int speed, size_t header_size,
	116	fw_iso_callback_t callback, void *callback_data)
3038e353 KH	117	{
3038e353 KH	118	struct fw_iso_context *ctx;
3038e353	119
4817ed24 SR	120	ctx = card->driver->allocate_iso_context(card,
4817ed24 SR	121	type, channel, header_size);
3038e353 KH	122	if (IS_ERR(ctx))
	123	return ctx;
	124
	125	ctx->card = card;
	126	ctx->type = type;
21efb3cf KH	127	ctx->channel = channel;
21efb3cf KH	128	ctx->speed = speed;
295e3feb	129	ctx->header_size = header_size;
3038e353 KH	130	ctx->callback = callback;
	131	ctx->callback_data = callback_data;
	132
3038e353 KH	133	return ctx;
3038e353 KH	134	}
3038e353 KH	135
	136	void fw_iso_context_destroy(struct fw_iso_context *ctx)
	137	{
	138	struct fw_card *card = ctx->card;
	139
3038e353 KH	140	card->driver->free_iso_context(ctx);
3038e353 KH	141	}
3038e353	142
53dca511 SR	143	int fw_iso_context_start(struct fw_iso_context *ctx,
53dca511 SR	144	int cycle, int sync, int tags)
3038e353	145	{
eb0306ea	146	return ctx->card->driver->start_iso(ctx, cycle, sync, tags);
3038e353	147	}
3038e353	148
53dca511 SR	149	int fw_iso_context_queue(struct fw_iso_context *ctx,
	150	struct fw_iso_packet *packet,
	151	struct fw_iso_buffer *buffer,
	152	unsigned long payload)
3038e353 KH	153	{
	154	struct fw_card *card = ctx->card;
	155
9aad8125	156	return card->driver->queue_iso(ctx, packet, buffer, payload);
3038e353	157	}
b8295668	158
53dca511	159	int fw_iso_context_stop(struct fw_iso_context *ctx)
b8295668 KH	160	{
	161	return ctx->card->driver->stop_iso(ctx);
	162	}
b1bda4cd JFSR	163
	164	/*
	165	* Isochronous bus resource management (channels, bandwidth), client side
	166	*/
	167
	168	static int manage_bandwidth(struct fw_card *card, int irm_id, int generation,
	169	int bandwidth, bool allocate)
	170	{
	171	__be32 data[2];
	172	int try, new, old = allocate ? BANDWIDTH_AVAILABLE_INITIAL : 0;
	173
	174	/*
	175	* On a 1394a IRM with low contention, try < 1 is enough.
	176	* On a 1394-1995 IRM, we need at least try < 2.
	177	* Let's just do try < 5.
	178	*/
	179	for (try = 0; try < 5; try++) {
	180	new = allocate ? old - bandwidth : old + bandwidth;
	181	if (new < 0 \|\| new > BANDWIDTH_AVAILABLE_INITIAL)
	182	break;
	183
	184	data[0] = cpu_to_be32(old);
	185	data[1] = cpu_to_be32(new);
	186	switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
	187	irm_id, generation, SCODE_100,
	188	CSR_REGISTER_BASE + CSR_BANDWIDTH_AVAILABLE,
	189	data, sizeof(data))) {
	190	case RCODE_GENERATION:
	191	/* A generation change frees all bandwidth. */
	192	return allocate ? -EAGAIN : bandwidth;
	193
	194	case RCODE_COMPLETE:
	195	if (be32_to_cpup(data) == old)
	196	return bandwidth;
	197
	198	old = be32_to_cpup(data);
	199	/* Fall through. */
	200	}
	201	}
	202
	203	return -EIO;
	204	}
	205
	206	static int manage_channel(struct fw_card *card, int irm_id, int generation,
	207	__be32 channels_mask, u64 offset, bool allocate)
	208	{
	209	__be32 data[2], c, old = allocate ? cpu_to_be32(~0) : 0;
	210	int i, retry = 5;
	211
	212	for (i = 0; i < 32; i++) {
	213	c = cpu_to_be32(1 << (31 - i));
	214	if (!(channels_mask & c))
	215	continue;
	216
	217	if (allocate == !(old & c))
	218	continue;
	219
	220	data[0] = old;
	221	data[1] = old ^ c;
	222	switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
	223	irm_id, generation, SCODE_100,
	224	offset, data, sizeof(data))) {
	225	case RCODE_GENERATION:
	226	/* A generation change frees all channels. */
227	return allocate ? -EAGAIN : i;
228
229	case RCODE_COMPLETE:
230	if (data[0] == old)
231	return i;
232
233	old = data[0];
234
235	/* Is the IRM 1394a-2000 compliant? */
236	if ((data[0] & c) != (data[1] & c))
237	continue;
238
239	/* 1394-1995 IRM, fall through to retry. */
240	default:
241	if (retry--)
242	i--;
243	}
244	}
245
246	return -EIO;
247	}
248
249	static void deallocate_channel(struct fw_card *card, int irm_id,
250	int generation, int channel)
251	{
252	__be32 mask;
253	u64 offset;
254
255	mask = channel < 32 ? cpu_to_be32(1 << (31 - channel)) :
256	cpu_to_be32(1 << (63 - channel));
257	offset = channel < 32 ? CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI :
258	CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO;
259
260	manage_channel(card, irm_id, generation, mask, offset, false);
261	}
262
263	/**
264	* fw_iso_resource_manage - Allocate or deallocate a channel and/or bandwidth
265	*
266	* In parameters: card, generation, channels_mask, bandwidth, allocate
267	* Out parameters: channel, bandwidth
268	* This function blocks (sleeps) during communication with the IRM.
269	* Allocates or deallocates at most one channel out of channels_mask.
270	*
271	* Returns channel < 0 if no channel was allocated or deallocated.
272	* Returns bandwidth = 0 if no bandwidth was allocated or deallocated.
273	*
274	* If generation is stale, deallocations succeed but allocations fail with
275	* channel = -EAGAIN.
276	*
277	* If channel (de)allocation fails, bandwidth (de)allocation fails too.
278	* If bandwidth allocation fails, no channel will be allocated either.
279	* If bandwidth deallocation fails, channel deallocation may still have been
280	* successful.
281	*/
282	void fw_iso_resource_manage(struct fw_card *card, int generation,
283	u64 channels_mask, int channel, int bandwidth,
284	bool allocate)
285	{
286	__be32 channels_hi = cpu_to_be32(channels_mask >> 32);
287	__be32 channels_lo = cpu_to_be32(channels_mask);
288	int irm_id, ret, c = -EINVAL;
289
290	spin_lock_irq(&card->lock);
291	irm_id = card->irm_node->node_id;
292	spin_unlock_irq(&card->lock);
293
294	if (channels_hi)
295	c = manage_channel(card, irm_id, generation, channels_hi,
296	CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI, allocate);
297	if (channels_lo && c < 0) {
298	c = manage_channel(card, irm_id, generation, channels_lo,
299	CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO, allocate);
300	if (c >= 0)
301	c += 32;
302	}
303	*channel = c;
304
305	if (channels_mask != 0 && c < 0)
306	*bandwidth = 0;
307
308	if (*bandwidth == 0)
309	return;
310
311	ret = manage_bandwidth(card, irm_id, generation, *bandwidth, allocate);
312	if (ret < 0)
313	*bandwidth = 0;
314
315	if (ret < 0 && c >= 0 && allocate) {
316	deallocate_channel(card, irm_id, generation, c);
317	*channel = ret;
318	}
319	}