[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, err;

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

		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,
			  u32 channels_mask, u64 offset, bool allocate)
{
	__be32 data[2], c, all, old;
	int i, retry = 5;

	old = all = allocate ? cpu_to_be32(~0) : 0;

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

		c = cpu_to_be32(1 << (31 - i));
		if ((old & c) != (all & 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)
{
	u32 mask;
	u64 offset;

	mask = channel < 32 ? 1 << channel : 1 << (channel - 32);
	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.
 * channels_mask is a bitfield with MSB for channel 63 and LSB for channel 0.
 * (Note, the IRM's CHANNELS_AVAILABLE is a big-endian bitfield with MSB for
 * channel 0 and LSB for channel 63.)
 * Allocates or deallocates as many bandwidth allocation units as specified.
 *
 * 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 allocation fails, no bandwidth will be allocated either.
 * If bandwidth allocation fails, no channel will be allocated either.
 * But deallocations of channel and bandwidth are tried independently
 * of each other's success.
 */
void fw_iso_resource_manage(struct fw_card *card, int generation,
			    u64 channels_mask, int *channel, int *bandwidth,
			    bool allocate)
{
	u32 channels_hi = channels_mask;	/* channels 31...0 */
	u32 channels_lo = channels_mask >> 32;	/* channels 63...32 */
	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 (allocate && 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 (allocate && ret < 0 && c >= 0) {
		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;
e1eff7a3	78
2dbd7d7e	79	return -ENOMEM;
9aad8125 KH	80	}
	81
	82	int fw_iso_buffer_map(struct fw_iso_buffer buffer, struct vm_area_struct vma)
	83	{
	84	unsigned long uaddr;
e1eff7a3	85	int i, err;
9aad8125 KH	86
	87	uaddr = vma->vm_start;
	88	for (i = 0; i < buffer->page_count; i++) {
e1eff7a3 SR	89	err = vm_insert_page(vma, uaddr, buffer->pages[i]);
	90	if (err)
	91	return err;
	92
9aad8125 KH	93	uaddr += PAGE_SIZE;
	94	}
	95
	96	return 0;
3038e353 KH	97	}
3038e353 KH	98
9aad8125 KH	99	void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer,
9aad8125 KH	100	struct fw_card *card)
3038e353 KH	101	{
3038e353 KH	102	int i;
9aad8125	103	dma_addr_t address;
3038e353	104
9aad8125 KH	105	for (i = 0; i < buffer->page_count; i++) {
	106	address = page_private(buffer->pages[i]);
	107	dma_unmap_page(card->device, address,
3038e353	108	PAGE_SIZE, DMA_TO_DEVICE);
9aad8125 KH	109	__free_page(buffer->pages[i]);
9aad8125 KH	110	}
3038e353	111
9aad8125 KH	112	kfree(buffer->pages);
9aad8125 KH	113	buffer->pages = NULL;
3038e353 KH	114	}
3038e353 KH	115
53dca511 SR	116	struct fw_iso_context fw_iso_context_create(struct fw_card card,
	117	int type, int channel, int speed, size_t header_size,
	118	fw_iso_callback_t callback, void *callback_data)
3038e353 KH	119	{
3038e353 KH	120	struct fw_iso_context *ctx;
3038e353	121
4817ed24 SR	122	ctx = card->driver->allocate_iso_context(card,
4817ed24 SR	123	type, channel, header_size);
3038e353 KH	124	if (IS_ERR(ctx))
	125	return ctx;
	126
	127	ctx->card = card;
	128	ctx->type = type;
21efb3cf KH	129	ctx->channel = channel;
21efb3cf KH	130	ctx->speed = speed;
295e3feb	131	ctx->header_size = header_size;
3038e353 KH	132	ctx->callback = callback;
	133	ctx->callback_data = callback_data;
	134
3038e353 KH	135	return ctx;
3038e353 KH	136	}
3038e353 KH	137
	138	void fw_iso_context_destroy(struct fw_iso_context *ctx)
	139	{
	140	struct fw_card *card = ctx->card;
	141
3038e353 KH	142	card->driver->free_iso_context(ctx);
3038e353 KH	143	}
3038e353	144
53dca511 SR	145	int fw_iso_context_start(struct fw_iso_context *ctx,
53dca511 SR	146	int cycle, int sync, int tags)
3038e353	147	{
eb0306ea	148	return ctx->card->driver->start_iso(ctx, cycle, sync, tags);
3038e353	149	}
3038e353	150
53dca511 SR	151	int fw_iso_context_queue(struct fw_iso_context *ctx,
	152	struct fw_iso_packet *packet,
	153	struct fw_iso_buffer *buffer,
	154	unsigned long payload)
3038e353 KH	155	{
	156	struct fw_card *card = ctx->card;
	157
9aad8125	158	return card->driver->queue_iso(ctx, packet, buffer, payload);
3038e353	159	}
b8295668	160
53dca511	161	int fw_iso_context_stop(struct fw_iso_context *ctx)
b8295668 KH	162	{
	163	return ctx->card->driver->stop_iso(ctx);
	164	}
b1bda4cd JFSR	165
	166	/*
	167	* Isochronous bus resource management (channels, bandwidth), client side
	168	*/
	169
	170	static int manage_bandwidth(struct fw_card *card, int irm_id, int generation,
	171	int bandwidth, bool allocate)
	172	{
	173	__be32 data[2];
	174	int try, new, old = allocate ? BANDWIDTH_AVAILABLE_INITIAL : 0;
	175
	176	/*
	177	* On a 1394a IRM with low contention, try < 1 is enough.
	178	* On a 1394-1995 IRM, we need at least try < 2.
	179	* Let's just do try < 5.
	180	*/
	181	for (try = 0; try < 5; try++) {
	182	new = allocate ? old - bandwidth : old + bandwidth;
	183	if (new < 0 \|\| new > BANDWIDTH_AVAILABLE_INITIAL)
	184	break;
	185
	186	data[0] = cpu_to_be32(old);
	187	data[1] = cpu_to_be32(new);
	188	switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
	189	irm_id, generation, SCODE_100,
	190	CSR_REGISTER_BASE + CSR_BANDWIDTH_AVAILABLE,
	191	data, sizeof(data))) {
	192	case RCODE_GENERATION:
	193	/* A generation change frees all bandwidth. */
	194	return allocate ? -EAGAIN : bandwidth;
	195
	196	case RCODE_COMPLETE:
	197	if (be32_to_cpup(data) == old)
	198	return bandwidth;
	199
	200	old = be32_to_cpup(data);
	201	/* Fall through. */
	202	}
	203	}
	204
	205	return -EIO;
	206	}
	207
	208	static int manage_channel(struct fw_card *card, int irm_id, int generation,
5d9cb7d2	209	u32 channels_mask, u64 offset, bool allocate)
b1bda4cd	210	{
5d9cb7d2	211	__be32 data[2], c, all, old;
b1bda4cd JFSR	212	int i, retry = 5;
b1bda4cd JFSR	213
5d9cb7d2 SR	214	old = all = allocate ? cpu_to_be32(~0) : 0;
5d9cb7d2 SR	215
b1bda4cd	216	for (i = 0; i < 32; i++) {
5d9cb7d2	217	if (!(channels_mask & 1 << i))
b1bda4cd JFSR	218	continue;
b1bda4cd JFSR	219
5d9cb7d2 SR	220	c = cpu_to_be32(1 << (31 - i));
5d9cb7d2 SR	221	if ((old & c) != (all & c))
b1bda4cd JFSR	222	continue;
	223
	224	data[0] = old;
	225	data[1] = old ^ c;
	226	switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
	227	irm_id, generation, SCODE_100,
	228	offset, data, sizeof(data))) {
	229	case RCODE_GENERATION:
	230	/* A generation change frees all channels. */
	231	return allocate ? -EAGAIN : i;
	232
	233	case RCODE_COMPLETE:
	234	if (data[0] == old)
	235	return i;
	236
	237	old = data[0];
	238
	239	/* Is the IRM 1394a-2000 compliant? */
5d9cb7d2	240	if ((data[0] & c) == (data[1] & c))
b1bda4cd JFSR	241	continue;
	242
	243	/* 1394-1995 IRM, fall through to retry. */
	244	default:
	245	if (retry--)
	246	i--;
	247	}
	248	}
	249
	250	return -EIO;
	251	}
	252
	253	static void deallocate_channel(struct fw_card *card, int irm_id,
	254	int generation, int channel)
	255	{
5d9cb7d2	256	u32 mask;
b1bda4cd JFSR	257	u64 offset;
b1bda4cd JFSR	258
5d9cb7d2	259	mask = channel < 32 ? 1 << channel : 1 << (channel - 32);
b1bda4cd JFSR	260	offset = channel < 32 ? CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI :
	261	CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO;
	262
	263	manage_channel(card, irm_id, generation, mask, offset, false);
	264	}
	265
	266	/**
	267	* fw_iso_resource_manage - Allocate or deallocate a channel and/or bandwidth
	268	*
	269	* In parameters: card, generation, channels_mask, bandwidth, allocate
	270	* Out parameters: channel, bandwidth
	271	* This function blocks (sleeps) during communication with the IRM.
5d9cb7d2	272	*
b1bda4cd	273	* Allocates or deallocates at most one channel out of channels_mask.
5d9cb7d2 SR	274	* channels_mask is a bitfield with MSB for channel 63 and LSB for channel 0.
	275	* (Note, the IRM's CHANNELS_AVAILABLE is a big-endian bitfield with MSB for
	276	* channel 0 and LSB for channel 63.)
	277	* Allocates or deallocates as many bandwidth allocation units as specified.
b1bda4cd JFSR	278	*
	279	* Returns channel < 0 if no channel was allocated or deallocated.
	280	* Returns bandwidth = 0 if no bandwidth was allocated or deallocated.
	281	*
	282	* If generation is stale, deallocations succeed but allocations fail with
	283	* channel = -EAGAIN.
	284	*
5d9cb7d2	285	* If channel allocation fails, no bandwidth will be allocated either.
b1bda4cd	286	* If bandwidth allocation fails, no channel will be allocated either.
5d9cb7d2 SR	287	* But deallocations of channel and bandwidth are tried independently
5d9cb7d2 SR	288	* of each other's success.
b1bda4cd JFSR	289	*/
	290	void fw_iso_resource_manage(struct fw_card *card, int generation,
	291	u64 channels_mask, int channel, int bandwidth,
	292	bool allocate)
	293	{
5d9cb7d2 SR	294	u32 channels_hi = channels_mask; /* channels 31...0 */
5d9cb7d2 SR	295	u32 channels_lo = channels_mask >> 32; /* channels 63...32 */
b1bda4cd JFSR	296	int irm_id, ret, c = -EINVAL;
	297
	298	spin_lock_irq(&card->lock);
	299	irm_id = card->irm_node->node_id;
	300	spin_unlock_irq(&card->lock);
	301
	302	if (channels_hi)
	303	c = manage_channel(card, irm_id, generation, channels_hi,
	304	CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI, allocate);
	305	if (channels_lo && c < 0) {
	306	c = manage_channel(card, irm_id, generation, channels_lo,
	307	CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO, allocate);
	308	if (c >= 0)
	309	c += 32;
	310	}
	311	*channel = c;
	312
5d9cb7d2	313	if (allocate && channels_mask != 0 && c < 0)
b1bda4cd JFSR	314	*bandwidth = 0;
	315
	316	if (*bandwidth == 0)
	317	return;
	318
	319	ret = manage_bandwidth(card, irm_id, generation, *bandwidth, allocate);
	320	if (ret < 0)
	321	*bandwidth = 0;
	322
5d9cb7d2	323	if (allocate && ret < 0 && c >= 0) {
b1bda4cd JFSR	324	deallocate_channel(card, irm_id, generation, c);
	325	*channel = ret;
	326	}
	327	}