zfcp_aux.c

linux-2.6.15.6

	if (sg_list != NULL) {
		zfcp_sg_list_free(sg_list);
		kfree(sg_list);
	}

	kfree(sense_data);

	return retval;
}


/**
 * zfcp_sg_list_alloc - create a scatter-gather list of the specified size
 * @sg_list: structure describing a scatter gather list
 * @size: size of scatter-gather list
 * Return: 0 on success, else -ENOMEM
 *
 * In sg_list->sg a pointer to the created scatter-gather list is returned,
 * or NULL if we run out of memory. sg_list->count specifies the number of
 * elements of the scatter-gather list. The maximum size of a single element
 * in the scatter-gather list is PAGE_SIZE.
 */
static inline int
zfcp_sg_list_alloc(struct zfcp_sg_list *sg_list, size_t size)
{
	struct scatterlist *sg;
	unsigned int i;
	int retval = 0;
	void *address;

	BUG_ON(sg_list == NULL);

	sg_list->count = size >> PAGE_SHIFT;
	if (size & ~PAGE_MASK)
		sg_list->count++;
	sg_list->sg = kmalloc(sg_list->count * sizeof(struct scatterlist),
			      GFP_KERNEL);
	if (sg_list->sg == NULL) {
		sg_list->count = 0;
		retval = -ENOMEM;
		goto out;
	}
	memset(sg_list->sg, 0, sg_list->count * sizeof(struct scatterlist));

	for (i = 0, sg = sg_list->sg; i < sg_list->count; i++, sg++) {
		sg->length = min(size, PAGE_SIZE);
		sg->offset = 0;
		address = (void *) get_zeroed_page(GFP_KERNEL);
		if (address == NULL) {
			sg_list->count = i;
			zfcp_sg_list_free(sg_list);
			retval = -ENOMEM;
			goto out;
		}
		zfcp_address_to_sg(address, sg);
		size -= sg->length;
	}

 out:
	return retval;
}


/**
 * zfcp_sg_list_free - free memory of a scatter-gather list
 * @sg_list: structure describing a scatter-gather list
 *
 * Memory for each element in the scatter-gather list is freed.
 * Finally sg_list->sg is freed itself and sg_list->count is reset.
 */
static inline void
zfcp_sg_list_free(struct zfcp_sg_list *sg_list)
{
	struct scatterlist *sg;
	unsigned int i;

	BUG_ON(sg_list == NULL);

	for (i = 0, sg = sg_list->sg; i < sg_list->count; i++, sg++)
		free_page((unsigned long) zfcp_sg_to_address(sg));

	sg_list->count = 0;
	kfree(sg_list->sg);
}

/**
 * zfcp_sg_size - determine size of a scatter-gather list
 * @sg: array of (struct scatterlist)
 * @sg_count: elements in array
 * Return: size of entire scatter-gather list
 */
size_t
zfcp_sg_size(struct scatterlist *sg, unsigned int sg_count)
{
	unsigned int i;
	struct scatterlist *p;
	size_t size;

	size = 0;
	for (i = 0, p = sg; i < sg_count; i++, p++) {
		BUG_ON(p == NULL);
		size += p->length;
	}

	return size;
}


/**
 * zfcp_sg_list_copy_from_user -copy data from user space to scatter-gather list
 * @sg_list: structure describing a scatter-gather list
 * @user_buffer: pointer to buffer in user space
 * @size: number of bytes to be copied
 * Return: 0 on success, -EFAULT if copy_from_user fails.
 */
static inline int
zfcp_sg_list_copy_from_user(struct zfcp_sg_list *sg_list,
			    void __user *user_buffer,
                            size_t size)
{
	struct scatterlist *sg;
	unsigned int length;
	void *zfcp_buffer;
	int retval = 0;

	BUG_ON(sg_list == NULL);

	if (zfcp_sg_size(sg_list->sg, sg_list->count) < size)
		return -EFAULT;

	for (sg = sg_list->sg; size > 0; sg++) {
		length = min((unsigned int)size, sg->length);
		zfcp_buffer = zfcp_sg_to_address(sg);
		if (copy_from_user(zfcp_buffer, user_buffer, length)) {
			retval = -EFAULT;
			goto out;
		}
		user_buffer += length;
		size -= length;
	}

 out:
	return retval;
}


/**
 * zfcp_sg_list_copy_to_user - copy data from scatter-gather list to user space
 * @user_buffer: pointer to buffer in user space
 * @sg_list: structure describing a scatter-gather list
 * @size: number of bytes to be copied
 * Return: 0 on success, -EFAULT if copy_to_user fails
 */
static inline int
zfcp_sg_list_copy_to_user(void __user  *user_buffer,
			  struct zfcp_sg_list *sg_list,
                          size_t size)
{
	struct scatterlist *sg;
	unsigned int length;
	void *zfcp_buffer;
	int retval = 0;

	BUG_ON(sg_list == NULL);

	if (zfcp_sg_size(sg_list->sg, sg_list->count) < size)
		return -EFAULT;

	for (sg = sg_list->sg; size > 0; sg++) {
		length = min((unsigned int) size, sg->length);
		zfcp_buffer = zfcp_sg_to_address(sg);
		if (copy_to_user(user_buffer, zfcp_buffer, length)) {
			retval = -EFAULT;
			goto out;
		}
		user_buffer += length;
		size -= length;
	}

 out:
	return retval;
}


#undef ZFCP_LOG_AREA

/****************************************************************/
/****** Functions for configuration/set-up of structures ********/
/****************************************************************/

#define ZFCP_LOG_AREA			ZFCP_LOG_AREA_CONFIG

/**
 * zfcp_get_unit_by_lun - find unit in unit list of port by FCP LUN
 * @port: pointer to port to search for unit
 * @fcp_lun: FCP LUN to search for
 * Traverse list of all units of a port and return pointer to a unit
 * with the given FCP LUN.
 */
struct zfcp_unit *
zfcp_get_unit_by_lun(struct zfcp_port *port, fcp_lun_t fcp_lun)
{
	struct zfcp_unit *unit;
	int found = 0;

	list_for_each_entry(unit, &port->unit_list_head, list) {
		if ((unit->fcp_lun == fcp_lun) &&
		    !atomic_test_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status))
		{
			found = 1;
			break;
		}
	}
	return found ? unit : NULL;
}

/**
 * zfcp_get_port_by_wwpn - find port in port list of adapter by wwpn
 * @adapter: pointer to adapter to search for port
 * @wwpn: wwpn to search for
 * Traverse list of all ports of an adapter and return pointer to a port
 * with the given wwpn.
 */
struct zfcp_port *
zfcp_get_port_by_wwpn(struct zfcp_adapter *adapter, wwn_t wwpn)
{
	struct zfcp_port *port;
	int found = 0;

	list_for_each_entry(port, &adapter->port_list_head, list) {
		if ((port->wwpn == wwpn) &&
		    !(atomic_read(&port->status) &
		      (ZFCP_STATUS_PORT_NO_WWPN | ZFCP_STATUS_COMMON_REMOVE))) {
			found = 1;
			break;
		}
	}
	return found ? port : NULL;
}

/**
 * zfcp_get_port_by_did - find port in port list of adapter by d_id
 * @adapter: pointer to adapter to search for port
 * @d_id: d_id to search for
 * Traverse list of all ports of an adapter and return pointer to a port
 * with the given d_id.
 */
struct zfcp_port *
zfcp_get_port_by_did(struct zfcp_adapter *adapter, u32 d_id)
{
	struct zfcp_port *port;
	int found = 0;

	list_for_each_entry(port, &adapter->port_list_head, list) {
		if ((port->d_id == d_id) &&
		    !atomic_test_mask(ZFCP_STATUS_COMMON_REMOVE, &port->status))
		{
			found = 1;
			break;
		}
	}
	return found ? port : NULL;
}

/**
 * zfcp_get_adapter_by_busid - find adpater in adapter list by bus_id
 * @bus_id: bus_id to search for
 * Traverse list of all adapters and return pointer to an adapter
 * with the given bus_id.
 */
struct zfcp_adapter *
zfcp_get_adapter_by_busid(char *bus_id)
{
	struct zfcp_adapter *adapter;
	int found = 0;

	list_for_each_entry(adapter, &zfcp_data.adapter_list_head, list) {
		if ((strncmp(bus_id, zfcp_get_busid_by_adapter(adapter),
			     BUS_ID_SIZE) == 0) &&
		    !atomic_test_mask(ZFCP_STATUS_COMMON_REMOVE,
				      &adapter->status)){
			found = 1;
			break;
		}
	}
	return found ? adapter : NULL;
}

/**
 * zfcp_unit_enqueue - enqueue unit to unit list of a port.
 * @port: pointer to port where unit is added
 * @fcp_lun: FCP LUN of unit to be enqueued
 * Return: pointer to enqueued unit on success, NULL on error
 * Locks: config_sema must be held to serialize changes to the unit list
 *
 * Sets up some unit internal structures and creates sysfs entry.
 */
struct zfcp_unit *
zfcp_unit_enqueue(struct zfcp_port *port, fcp_lun_t fcp_lun)
{
	struct zfcp_unit *unit, *tmp_unit;
	scsi_lun_t scsi_lun;
	int found;

	/*
	 * check that there is no unit with this FCP_LUN already in list
	 * and enqueue it.
	 * Note: Unlike for the adapter and the port, this is an error
	 */
	read_lock_irq(&zfcp_data.config_lock);
	unit = zfcp_get_unit_by_lun(port, fcp_lun);
	read_unlock_irq(&zfcp_data.config_lock);
	if (unit)
		return NULL;

	unit = kmalloc(sizeof (struct zfcp_unit), GFP_KERNEL);
	if (!unit)
		return NULL;
	memset(unit, 0, sizeof (struct zfcp_unit));

	/* initialise reference count stuff */
	atomic_set(&unit->refcount, 0);
	init_waitqueue_head(&unit->remove_wq);

	unit->port = port;
	unit->fcp_lun = fcp_lun;

	/* setup for sysfs registration */
	snprintf(unit->sysfs_device.bus_id, BUS_ID_SIZE, "0x%016llx", fcp_lun);
	unit->sysfs_device.parent = &port->sysfs_device;
	unit->sysfs_device.release = zfcp_sysfs_unit_release;
	dev_set_drvdata(&unit->sysfs_device, unit);

	/* mark unit unusable as long as sysfs registration is not complete */
	atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);

	if (device_register(&unit->sysfs_device)) {
		kfree(unit);
		return NULL;
	}

	if (zfcp_sysfs_unit_create_files(&unit->sysfs_device)) {
		device_unregister(&unit->sysfs_device);
		return NULL;
	}

	zfcp_unit_get(unit);

	scsi_lun = 0;
	found = 0;
	write_lock_irq(&zfcp_data.config_lock);
	list_for_each_entry(tmp_unit, &port->unit_list_head, list) {
		if (tmp_unit->scsi_lun != scsi_lun) {
			found = 1;
			break;
		}
		scsi_lun++;
	}
	unit->scsi_lun = scsi_lun;
	if (found)
		list_add_tail(&unit->list, &tmp_unit->list);
	else
		list_add_tail(&unit->list, &port->unit_list_head);
	atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
	atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status);
	write_unlock_irq(&zfcp_data.config_lock);

	port->units++;
	zfcp_port_get(port);

	return unit;
}

void
zfcp_unit_dequeue(struct zfcp_unit *unit)
{
	zfcp_unit_wait(unit);
	write_lock_irq(&zfcp_data.config_lock);
	list_del(&unit->list);
	write_unlock_irq(&zfcp_data.config_lock);
	unit->port->units--;
	zfcp_port_put(unit->port);
	zfcp_sysfs_unit_remove_files(&unit->sysfs_device);
	device_unregister(&unit->sysfs_device);
}

static void *
zfcp_mempool_alloc(gfp_t gfp_mask, void *size)
{
	return kmalloc((size_t) size, gfp_mask);
}

static void
zfcp_mempool_free(void *element, void *size)
{
	kfree(element);
}

/*
 * Allocates a combined QTCB/fsf_req buffer for erp actions and fcp/SCSI
 * commands.
 * It also genrates fcp-nameserver request/response buffer and unsolicited 
 * status read fsf_req buffers.
 *
 * locks:       must only be called with zfcp_data.config_sema taken
 */
static int
zfcp_allocate_low_mem_buffers(struct zfcp_adapter *adapter)
{
	adapter->pool.fsf_req_erp =
		mempool_create(ZFCP_POOL_FSF_REQ_ERP_NR,
			       zfcp_mempool_alloc, zfcp_mempool_free, (void *)
			       sizeof(struct zfcp_fsf_req_pool_element));

	if (NULL == adapter->pool.fsf_req_erp)
		return -ENOMEM;

	adapter->pool.fsf_req_scsi =
		mempool_create(ZFCP_POOL_FSF_REQ_SCSI_NR,
			       zfcp_mempool_alloc, zfcp_mempool_free, (void *)
			       sizeof(struct zfcp_fsf_req_pool_element));

	if (NULL == adapter->pool.fsf_req_scsi)
		return -ENOMEM;

	adapter->pool.fsf_req_abort =
		mempool_create(ZFCP_POOL_FSF_REQ_ABORT_NR,
			       zfcp_mempool_alloc, zfcp_mempool_free, (void *)
			       sizeof(struct zfcp_fsf_req_pool_element));

	if (NULL == adapter->pool.fsf_req_abort)
		return -ENOMEM;

	adapter->pool.fsf_req_status_read =
		mempool_create(ZFCP_POOL_STATUS_READ_NR,
			       zfcp_mempool_alloc, zfcp_mempool_free,
			       (void *) sizeof(struct zfcp_fsf_req));

	if (NULL == adapter->pool.fsf_req_status_read)
		return -ENOMEM;

	adapter->pool.data_status_read =
		mempool_create(ZFCP_POOL_STATUS_READ_NR,
			       zfcp_mempool_alloc, zfcp_mempool_free,
			       (void *) sizeof(struct fsf_status_read_buffer));

	if (NULL == adapter->pool.data_status_read)