csr1212.c

Ieee1394驱动实现

	}

	/* Remove unused, excess cache regions */
	while (cache) {
		struct csr1212_csr_rom_cache *oc = cache;

		cache = cache->next;
		csr1212_remove_cache(csr, oc);
	}

	/* Go through the list backward so that when done, the correct CRC
	 * will be calculated for the Extended ROM areas. */
	for (cache = csr->cache_tail; cache; cache = cache->prev) {
		/* Only Extended ROM caches should have this set. */
		if (cache->ext_rom) {
			int leaf_size;

			/* Make sure the Extended ROM leaf is a multiple of
			 * max_rom in size. */
			BUG_ON(csr->max_rom < 1);
			leaf_size = (cache->len + (csr->max_rom - 1)) &
				~(csr->max_rom - 1);

			/* Zero out the unused ROM region */
			memset(cache->data + bytes_to_quads(cache->len), 0x00,
			       leaf_size - cache->len);

			/* Subtract leaf header */
			leaf_size -= sizeof(u32);

			/* Update the Extended ROM leaf length */
			cache->ext_rom->value.leaf.len =
				bytes_to_quads(leaf_size);
		} else {
			/* Zero out the unused ROM region */
			memset(cache->data + bytes_to_quads(cache->len), 0x00,
			       cache->size - cache->len);
		}

		/* Copy the data into the cache buffer */
		csr1212_fill_cache(cache);

		if (cache != csr->cache_head) {
			/* Set the length and CRC of the extended ROM. */
			struct csr1212_keyval_img *kvi =
				(struct csr1212_keyval_img*)cache->data;
			u16 len = bytes_to_quads(cache->len) - 1;

			kvi->length = cpu_to_be16(len);
			kvi->crc = csr1212_crc16(kvi->data, len);
		}
	}

	return CSR1212_SUCCESS;
}

int csr1212_read(struct csr1212_csr *csr, u32 offset, void *buffer, u32 len)
{
	struct csr1212_csr_rom_cache *cache;

	for (cache = csr->cache_head; cache; cache = cache->next)
		if (offset >= cache->offset &&
		    (offset + len) <= (cache->offset + cache->size)) {
			memcpy(buffer, &cache->data[
					bytes_to_quads(offset - cache->offset)],
			       len);
			return CSR1212_SUCCESS;
		}

	return -ENOENT;
}


/* Parse a chunk of data as a Config ROM */

static int csr1212_parse_bus_info_block(struct csr1212_csr *csr)
{
	struct csr1212_bus_info_block_img *bi;
	struct csr1212_cache_region *cr;
	int i;
	int ret;

	/* IEEE 1212 says that the entire bus info block should be readable in
	 * a single transaction regardless of the max_rom value.
	 * Unfortunately, many IEEE 1394 devices do not abide by that, so the
	 * bus info block will be read 1 quadlet at a time.  The rest of the
	 * ConfigROM will be read according to the max_rom field. */
	for (i = 0; i < csr->bus_info_len; i += sizeof(u32)) {
		ret = csr->ops->bus_read(csr, CSR1212_CONFIG_ROM_SPACE_BASE + i,
			sizeof(u32), &csr->cache_head->data[bytes_to_quads(i)],
			csr->private);
		if (ret != CSR1212_SUCCESS)
			return ret;

		/* check ROM header's info_length */
		if (i == 0 &&
		    be32_to_cpu(csr->cache_head->data[0]) >> 24 !=
		    bytes_to_quads(csr->bus_info_len) - 1)
			return -EINVAL;
	}

	bi = (struct csr1212_bus_info_block_img*)csr->cache_head->data;
	csr->crc_len = quads_to_bytes(bi->crc_length);

	/* IEEE 1212 recommends that crc_len be equal to bus_info_len, but that
	 * is not always the case, so read the rest of the crc area 1 quadlet at
	 * a time. */
	for (i = csr->bus_info_len; i <= csr->crc_len; i += sizeof(u32)) {
		ret = csr->ops->bus_read(csr, CSR1212_CONFIG_ROM_SPACE_BASE + i,
			sizeof(u32), &csr->cache_head->data[bytes_to_quads(i)],
			csr->private);
		if (ret != CSR1212_SUCCESS)
			return ret;
	}

	/* Apparently there are many different wrong implementations of the CRC
	 * algorithm.  We don't fail, we just warn. */
	if ((csr1212_crc16(bi->data, bi->crc_length) != bi->crc) &&
	    (csr1212_msft_crc16(bi->data, bi->crc_length) != bi->crc))
		printk(KERN_DEBUG "IEEE 1394 device has ROM CRC error\n");

	cr = CSR1212_MALLOC(sizeof(*cr));
	if (!cr)
		return -ENOMEM;

	cr->next = NULL;
	cr->prev = NULL;
	cr->offset_start = 0;
	cr->offset_end = csr->crc_len + 4;

	csr->cache_head->filled_head = cr;
	csr->cache_head->filled_tail = cr;

	return CSR1212_SUCCESS;
}

#define CSR1212_KV_KEY(q)	(be32_to_cpu(q) >> CSR1212_KV_KEY_SHIFT)
#define CSR1212_KV_KEY_TYPE(q)	(CSR1212_KV_KEY(q) >> CSR1212_KV_KEY_TYPE_SHIFT)
#define CSR1212_KV_KEY_ID(q)	(CSR1212_KV_KEY(q) & CSR1212_KV_KEY_ID_MASK)
#define CSR1212_KV_VAL_MASK	0xffffff
#define CSR1212_KV_VAL(q)	(be32_to_cpu(q) & CSR1212_KV_VAL_MASK)

static int
csr1212_parse_dir_entry(struct csr1212_keyval *dir, u32 ki, u32 kv_pos)
{
	int ret = CSR1212_SUCCESS;
	struct csr1212_keyval *k = NULL;
	u32 offset;

	switch (CSR1212_KV_KEY_TYPE(ki)) {
	case CSR1212_KV_TYPE_IMMEDIATE:
		k = csr1212_new_immediate(CSR1212_KV_KEY_ID(ki),
					  CSR1212_KV_VAL(ki));
		if (!k) {
			ret = -ENOMEM;
			goto out;
		}

		k->refcnt = 0;	/* Don't keep local reference when parsing. */
		break;

	case CSR1212_KV_TYPE_CSR_OFFSET:
		k = csr1212_new_csr_offset(CSR1212_KV_KEY_ID(ki),
					   CSR1212_KV_VAL(ki));
		if (!k) {
			ret = -ENOMEM;
			goto out;
		}
		k->refcnt = 0;	/* Don't keep local reference when parsing. */
		break;

	default:
		/* Compute the offset from 0xffff f000 0000. */
		offset = quads_to_bytes(CSR1212_KV_VAL(ki)) + kv_pos;
		if (offset == kv_pos) {
			/* Uh-oh.  Can't have a relative offset of 0 for Leaves
			 * or Directories.  The Config ROM image is most likely
			 * messed up, so we'll just abort here. */
			ret = -EIO;
			goto out;
		}

		k = csr1212_find_keyval_offset(dir, offset);

		if (k)
			break;		/* Found it. */

		if (CSR1212_KV_KEY_TYPE(ki) == CSR1212_KV_TYPE_DIRECTORY)
			k = csr1212_new_directory(CSR1212_KV_KEY_ID(ki));
		else
			k = csr1212_new_leaf(CSR1212_KV_KEY_ID(ki), NULL, 0);

		if (!k) {
			ret = -ENOMEM;
			goto out;
		}
		k->refcnt = 0;	/* Don't keep local reference when parsing. */
		k->valid = 0;	/* Contents not read yet so it's not valid. */
		k->offset = offset;

		k->prev = dir;
		k->next = dir->next;
		dir->next->prev = k;
		dir->next = k;
	}
	ret = csr1212_attach_keyval_to_directory(dir, k);
out:
	if (ret != CSR1212_SUCCESS && k != NULL)
		free_keyval(k);
	return ret;
}

int csr1212_parse_keyval(struct csr1212_keyval *kv,
			 struct csr1212_csr_rom_cache *cache)
{
	struct csr1212_keyval_img *kvi;
	int i;
	int ret = CSR1212_SUCCESS;
	int kvi_len;

	kvi = (struct csr1212_keyval_img*)
		&cache->data[bytes_to_quads(kv->offset - cache->offset)];
	kvi_len = be16_to_cpu(kvi->length);

	/* Apparently there are many different wrong implementations of the CRC
	 * algorithm.  We don't fail, we just warn. */
	if ((csr1212_crc16(kvi->data, kvi_len) != kvi->crc) &&
	    (csr1212_msft_crc16(kvi->data, kvi_len) != kvi->crc))
		printk(KERN_DEBUG "IEEE 1394 device has ROM CRC error\n");

	switch (kv->key.type) {
	case CSR1212_KV_TYPE_DIRECTORY:
		for (i = 0; i < kvi_len; i++) {
			u32 ki = kvi->data[i];

			/* Some devices put null entries in their unit
			 * directories.  If we come across such an entry,
			 * then skip it. */
			if (ki == 0x0)
				continue;
			ret = csr1212_parse_dir_entry(kv, ki,
					kv->offset + quads_to_bytes(i + 1));
		}
		kv->value.directory.len = kvi_len;
		break;

	case CSR1212_KV_TYPE_LEAF:
		if (kv->key.id != CSR1212_KV_ID_EXTENDED_ROM) {
			size_t size = quads_to_bytes(kvi_len);

			kv->value.leaf.data = CSR1212_MALLOC(size);
			if (!kv->value.leaf.data) {
				ret = -ENOMEM;
				goto out;
			}

			kv->value.leaf.len = kvi_len;
			memcpy(kv->value.leaf.data, kvi->data, size);
		}
		break;
	}

	kv->valid = 1;
out:
	return ret;
}

static int
csr1212_read_keyval(struct csr1212_csr *csr, struct csr1212_keyval *kv)
{
	struct csr1212_cache_region *cr, *ncr, *newcr = NULL;
	struct csr1212_keyval_img *kvi = NULL;
	struct csr1212_csr_rom_cache *cache;
	int cache_index;
	u64 addr;
	u32 *cache_ptr;
	u16 kv_len = 0;

	BUG_ON(!csr || !kv || csr->max_rom < 1);

	/* First find which cache the data should be in (or go in if not read
	 * yet). */
	for (cache = csr->cache_head; cache; cache = cache->next)
		if (kv->offset >= cache->offset &&
		    kv->offset < (cache->offset + cache->size))
			break;

	if (!cache) {
		u32 q, cache_size;

		/* Only create a new cache for Extended ROM leaves. */
		if (kv->key.id != CSR1212_KV_ID_EXTENDED_ROM)
			return -EINVAL;

		if (csr->ops->bus_read(csr,
				       CSR1212_REGISTER_SPACE_BASE + kv->offset,
				       sizeof(u32), &q, csr->private))
			return -EIO;

		kv->value.leaf.len = be32_to_cpu(q) >> 16;

		cache_size = (quads_to_bytes(kv->value.leaf.len + 1) +
			      (csr->max_rom - 1)) & ~(csr->max_rom - 1);

		cache = csr1212_rom_cache_malloc(kv->offset, cache_size);
		if (!cache)
			return -ENOMEM;

		kv->value.leaf.data = &cache->data[1];
		csr->cache_tail->next = cache;
		cache->prev = csr->cache_tail;
		cache->next = NULL;
		csr->cache_tail = cache;
		cache->filled_head =
			CSR1212_MALLOC(sizeof(*cache->filled_head));
		if (!cache->filled_head)
			return -ENOMEM;

		cache->filled_head->offset_start = 0;
		cache->filled_head->offset_end = sizeof(u32);
		cache->filled_tail = cache->filled_head;
		cache->filled_head->next = NULL;
		cache->filled_head->prev = NULL;
		cache->data[0] = q;

		/* Don't read the entire extended ROM now.  Pieces of it will
		 * be read when entries inside it are read. */
		return csr1212_parse_keyval(kv, cache);
	}

	cache_index = kv->offset - cache->offset;

	/* Now seach read portions of the cache to see if it is there. */
	for (cr = cache->filled_head; cr; cr = cr->next) {
		if (cache_index < cr->offset_start) {
			newcr = CSR1212_MALLOC(sizeof(*newcr));
			if (!newcr)
				return -ENOMEM;

			newcr->offset_start = cache_index & ~(csr->max_rom - 1);
			newcr->offset_end = newcr->offset_start;
			newcr->next = cr;
			newcr->prev = cr->prev;
			cr->prev = newcr;
			cr = newcr;
			break;
		} else if ((cache_index >= cr->offset_start) &&
			   (cache_index < cr->offset_end)) {
			kvi = (struct csr1212_keyval_img*)
				(&cache->data[bytes_to_quads(cache_index)]);
			kv_len = quads_to_bytes(be16_to_cpu(kvi->length) + 1);
			break;
		} else if (cache_index == cr->offset_end) {
			break;
		}
	}

	if (!cr) {
		cr = cache->filled_tail;
		newcr = CSR1212_MALLOC(sizeof(*newcr));
		if (!newcr)
			return -ENOMEM;

		newcr->offset_start = cache_index & ~(csr->max_rom - 1);
		newcr->offset_end = newcr->offset_start;
		newcr->prev = cr;
		newcr->next = cr->next;
		cr->next = newcr;
		cr = newcr;
		cache->filled_tail = newcr;
	}

	while(!kvi || cr->offset_end < cache_index + kv_len) {
		cache_ptr = &cache->data[bytes_to_quads(cr->offset_end &
							~(csr->max_rom - 1))];

		addr = (CSR1212_CSR_ARCH_REG_SPACE_BASE + cache->offset +
			cr->offset_end) & ~(csr->max_rom - 1);

		if (csr->ops->bus_read(csr, addr, csr->max_rom, cache_ptr,
				       csr->private)) {
			if (csr->max_rom == 4)
				/* We've got problems! */
				return -EIO;

			/* Apperently the max_rom value was a lie, set it to
			 * do quadlet reads and try again. */
			csr->max_rom = 4;
			continue;
		}

		cr->offset_end += csr->max_rom - (cr->offset_end &
						  (csr->max_rom - 1));

		if (!kvi && (cr->offset_end > cache_index)) {
			kvi = (struct csr1212_keyval_img*)
				(&cache->data[bytes_to_quads(cache_index)]);
			kv_len = quads_to_bytes(be16_to_cpu(kvi->length) + 1);
		}

		if ((kv_len + (kv->offset - cache->offset)) > cache->size) {
			/* The Leaf or Directory claims its length extends
			 * beyond the ConfigROM image region and thus beyond the
			 * end of our cache region.  Therefore, we abort now
			 * rather than seg faulting later. */
			return -EIO;
		}

		ncr = cr->next;

		if (ncr && (cr->offset_end >= ncr->offset_start)) {
			/* consolidate region entries */
			ncr->offset_start = cr->offset_start;

			if (cr->prev)
				cr->prev->next = cr->next;
			ncr->prev = cr->prev;
			if (cache->filled_head == cr)
				cache->filled_head = ncr;
			CSR1212_FREE(cr);
			cr = ncr;
		}
	}

	return csr1212_parse_keyval(kv, cache);
}

struct csr1212_keyval *
csr1212_get_keyval(struct csr1212_csr *csr, struct csr1212_keyval *kv)
{
	if (!kv)
		return NULL;
	if (!kv->valid)
		if (csr1212_read_keyval(csr, kv) != CSR1212_SUCCESS)
			return NULL;
	return kv;
}

int csr1212_parse_csr(struct csr1212_csr *csr)
{
	static const int mr_map[] = { 4, 64, 1024, 0 };
	struct csr1212_dentry *dentry;
	int ret;

	BUG_ON(!csr || !csr->ops || !csr->ops->bus_read);

	ret = csr1212_parse_bus_info_block(csr);
	if (ret != CSR1212_SUCCESS)
		return ret;

	if (!csr->ops->get_max_rom) {
		csr->max_rom = mr_map[0];	/* default value */
	} else {
		int i = csr->ops->get_max_rom(csr->bus_info_data,
					      csr->private);
		if (i & ~0x3)
			return -EINVAL;
		csr->max_rom = mr_map[i];
	}

	csr->cache_head->layout_head = csr->root_kv;
	csr->cache_head->layout_tail = csr->root_kv;

	csr->root_kv->offset = (CSR1212_CONFIG_ROM_SPACE_BASE & 0xffff) +
		csr->bus_info_len;

	csr->root_kv->valid = 0;
	csr->root_kv->next = csr->root_kv;
	csr->root_kv->prev = csr->root_kv;
	ret = csr1212_read_keyval(csr, csr->root_kv);
	if (ret != CSR1212_SUCCESS)
		return ret;

	/* Scan through the Root directory finding all extended ROM regions
	 * and make cache regions for them */
	for (dentry = csr->root_kv->value.directory.dentries_head;
	     dentry; dentry = dentry->next) {
		if (dentry->kv->key.id == CSR1212_KV_ID_EXTENDED_ROM &&
			!dentry->kv->valid) {
			ret = csr1212_read_keyval(csr, dentry->kv);
			if (ret != CSR1212_SUCCESS)
				return ret;
		}
	}

	return CSR1212_SUCCESS;
}