iucv.c

linux-2.6.15.6

}

/**
 * release_param - Release a parameter buffer.
 * @p: A pointer to a struct iucv_param, previously obtained by calling
 *     grab_param().
 *
 * This function marks the specified parameter buffer "unused".
 */
static __inline__ void
release_param(void *p)
{
	atomic_set(&((iucv_param *)p)->in_use, 0);
}

/**
 * iucv_add_handler: - Add a new handler
 * @new_handler: handle that is being entered into chain.
 *
 * Places new handle on iucv_handler_table, if identical handler is not
 * found.
 *
 * Returns: 0 on success, !0 on failure (handler already in chain).
 */
static int
iucv_add_handler (handler *new)
{
	ulong flags;

	iucv_debug(1, "entering");
	iucv_dumpit("handler:", new, sizeof(handler));

	spin_lock_irqsave (&iucv_lock, flags);
	if (!list_empty(&iucv_handler_table)) {
		struct list_head *lh;

		/**
		 * Search list for handler with identical id. If one
		 * is found, the new handler is _not_ added.
		 */
		list_for_each(lh, &iucv_handler_table) {
			handler *h = list_entry(lh, handler, list);
			if (!memcmp(&new->id, &h->id, sizeof(h->id))) {
				iucv_debug(1, "ret 1");
				spin_unlock_irqrestore (&iucv_lock, flags);
				return 1;
			}
		}
	}
	/**
	 * If we get here, no handler was found.
	 */
	INIT_LIST_HEAD(&new->list);
	list_add(&new->list, &iucv_handler_table);
	spin_unlock_irqrestore (&iucv_lock, flags);

	iucv_debug(1, "exiting");
	return 0;
}

/**
 * b2f0:
 * @code: identifier of IUCV call to CP.
 * @parm: pointer to 40 byte iparml area passed to CP
 *
 * Calls CP to execute IUCV commands.
 *
 * Returns: return code from CP's IUCV call
 */
static __inline__ ulong
b2f0(__u32 code, void *parm)
{
	iucv_dumpit("iparml before b2f0 call:", parm, sizeof(iucv_param));

	asm volatile (
		"LRA   1,0(%1)\n\t"
		"LR    0,%0\n\t"
		".long 0xb2f01000"
		:
		: "d" (code), "a" (parm)
		: "0", "1"
		);

	iucv_dumpit("iparml after b2f0 call:", parm, sizeof(iucv_param));

	return (unsigned long)*((__u8 *)(parm + 3));
}

/*
 * Name: iucv_add_pathid
 * Purpose: Adds a path id to the system.
 * Input: pathid -  pathid that is going to be entered into system
 *        handle -  address of handler that the pathid will be associated
 *		   with.
 *        pgm_data - token passed in by application.
 * Output: 0: successful addition of pathid
 *	   - EINVAL - pathid entry is being used by another application
 *	   - ENOMEM - storage allocation for a new pathid table failed
*/
static int
__iucv_add_pathid(__u16 pathid, handler *handler)
{

	iucv_debug(1, "entering");

	iucv_debug(1, "handler is pointing to %p", handler);

	if (pathid > (max_connections - 1))
		return -EINVAL;

	if (iucv_pathid_table[pathid]) {
		iucv_debug(1, "pathid entry is %p", iucv_pathid_table[pathid]);
		printk(KERN_WARNING
		       "%s: Pathid being used, error.\n", __FUNCTION__);
		return -EINVAL;
	}
	iucv_pathid_table[pathid] = handler;

	iucv_debug(1, "exiting");
	return 0;
}				/* end of add_pathid function */

static int
iucv_add_pathid(__u16 pathid, handler *handler)
{
	ulong flags;
	int rc;

	spin_lock_irqsave (&iucv_lock, flags);
	rc = __iucv_add_pathid(pathid, handler);
	spin_unlock_irqrestore (&iucv_lock, flags);
	return rc;
}

static void
iucv_remove_pathid(__u16 pathid)
{
	ulong flags;

	if (pathid > (max_connections - 1))
		return;

	spin_lock_irqsave (&iucv_lock, flags);
	iucv_pathid_table[pathid] = NULL;
	spin_unlock_irqrestore (&iucv_lock, flags);
}

/**
 * iucv_declare_buffer_cpuid
 * Register at VM for subsequent IUCV operations. This is executed
 * on the reserved CPU iucv_cpuid. Called from iucv_declare_buffer().
 */
static void
iucv_declare_buffer_cpuid (void *result)
{
	iparml_db *parm;

	parm = (iparml_db *)grab_param();
	parm->ipbfadr1 = virt_to_phys(iucv_external_int_buffer);
	if ((*((ulong *)result) = b2f0(DECLARE_BUFFER, parm)) == 1)
		*((ulong *)result) = parm->iprcode;
	release_param(parm);
}

/**
 * iucv_retrieve_buffer_cpuid:
 * Unregister IUCV usage at VM. This is always executed on the same
 * cpu that registered the buffer to VM.
 * Called from iucv_retrieve_buffer().
 */
static void
iucv_retrieve_buffer_cpuid (void *cpu)
{
	iparml_control *parm;

	parm = (iparml_control *)grab_param();
	b2f0(RETRIEVE_BUFFER, parm);
	release_param(parm);
}

/**
 * Name: iucv_declare_buffer
 * Purpose: Specifies the guests real address of an external
 *          interrupt.
 * Input: void
 * Output: iprcode - return code from b2f0 call
 */
static int
iucv_declare_buffer (void)
{
	unsigned long flags;
	ulong b2f0_result;

	iucv_debug(1, "entering");
	b2f0_result = -ENODEV;
	spin_lock_irqsave (&iucv_lock, flags);
	if (iucv_cpuid == -1) {
		/* Reserve any cpu for use by iucv. */
		iucv_cpuid = smp_get_cpu(CPU_MASK_ALL);
		spin_unlock_irqrestore (&iucv_lock, flags);
		smp_call_function_on(iucv_declare_buffer_cpuid,
			&b2f0_result, 0, 1, iucv_cpuid);
		if (b2f0_result) {
			smp_put_cpu(iucv_cpuid);
			iucv_cpuid = -1;
		}
		iucv_debug(1, "Address of EIB = %p", iucv_external_int_buffer);
	} else {
		spin_unlock_irqrestore (&iucv_lock, flags);
		b2f0_result = 0;
	}
	iucv_debug(1, "exiting");
	return b2f0_result;
}

/**
 * iucv_retrieve_buffer:
 *
 * Terminates all use of IUCV.
 * Returns: return code from CP
 */
static int
iucv_retrieve_buffer (void)
{
	iucv_debug(1, "entering");
	if (iucv_cpuid != -1) {
		smp_call_function_on(iucv_retrieve_buffer_cpuid,
				     0, 0, 1, iucv_cpuid);
		/* Release the cpu reserved by iucv_declare_buffer. */
		smp_put_cpu(iucv_cpuid);
		iucv_cpuid = -1;
	}
	iucv_debug(1, "exiting");
	return 0;
}

/**
 * iucv_remove_handler:
 * @users_handler: handler to be removed
 *
 * Remove handler when application unregisters.
 */
static void
iucv_remove_handler(handler *handler)
{
	unsigned long flags;

	if ((!iucv_pathid_table) || (!handler))
		return;

	iucv_debug(1, "entering");

	spin_lock_irqsave (&iucv_lock, flags);
	list_del(&handler->list);
	if (list_empty(&iucv_handler_table)) {
		if (register_flag) {
			unregister_external_interrupt(0x4000, iucv_irq_handler);
			register_flag = 0;
		}
	}
	spin_unlock_irqrestore (&iucv_lock, flags);

	iucv_debug(1, "exiting");
	return;
}

/**
 * iucv_register_program:
 * @pgmname:  user identification
 * @userid:   machine identification
 * @pgmmask:  Indicates which bits in the pgmname and userid combined will be
 *            used to determine who is given control.
 * @ops:      Address of interrupt handler table.
 * @pgm_data: Application data to be passed to interrupt handlers.
 *
 * Registers an application with IUCV.
 * Returns:
 *           The address of handler, or NULL on failure.
 * NOTE on pgmmask:
 *   If pgmname, userid and pgmmask are provided, pgmmask is entered into the
 *   handler as is.
 *   If pgmmask is NULL, the internal mask is set to all 0xff's
 *   When userid is NULL, the first 8 bytes of the internal mask are forced
 *   to 0x00.
 *   If pgmmask and userid are NULL, the first 8 bytes of the internal mask
 *   are forced to 0x00 and the last 16 bytes to 0xff.
 */

iucv_handle_t
iucv_register_program (__u8 pgmname[16],
		       __u8 userid[8],
		       __u8 pgmmask[24],
		       iucv_interrupt_ops_t * ops, void *pgm_data)
{
	ulong rc = 0;		/* return code from function calls */
	handler *new_handler;

	iucv_debug(1, "entering");

	if (ops == NULL) {
		/* interrupt table is not defined */
		printk(KERN_WARNING "%s: Interrupt table is not defined, "
		       "exiting\n", __FUNCTION__);
		return NULL;
	}
	if (!pgmname) {
		printk(KERN_WARNING "%s: pgmname not provided\n", __FUNCTION__);
		return NULL;
	}

	/* Allocate handler entry */
	new_handler = (handler *)kmalloc(sizeof(handler), GFP_ATOMIC);
	if (new_handler == NULL) {
		printk(KERN_WARNING "%s: storage allocation for new handler "
		       "failed.\n", __FUNCTION__);
		return NULL;
	}

	if (!iucv_pathid_table) {
		if (iucv_init()) {
			kfree(new_handler);
			return NULL;
		}

		max_connections = iucv_query_maxconn();
		iucv_pathid_table = kmalloc(max_connections * sizeof(handler *),
				       GFP_ATOMIC);
		if (iucv_pathid_table == NULL) {
			printk(KERN_WARNING "%s: iucv_pathid_table storage "
			       "allocation failed\n", __FUNCTION__);
			kfree(new_handler);
			return NULL;
		}
		memset (iucv_pathid_table, 0, max_connections * sizeof(handler *));
	}
	memset(new_handler, 0, sizeof (handler));
	memcpy(new_handler->id.user_data, pgmname,
		sizeof (new_handler->id.user_data));
	if (userid) {
		memcpy (new_handler->id.userid, userid,
			sizeof (new_handler->id.userid));
		ASCEBC (new_handler->id.userid,
			sizeof (new_handler->id.userid));
		EBC_TOUPPER (new_handler->id.userid,
			     sizeof (new_handler->id.userid));
		
		if (pgmmask) {
			memcpy (new_handler->id.mask, pgmmask,
				sizeof (new_handler->id.mask));
		} else {
			memset (new_handler->id.mask, 0xFF,
				sizeof (new_handler->id.mask));
		}
	} else {
		if (pgmmask) {
			memcpy (new_handler->id.mask, pgmmask,
				sizeof (new_handler->id.mask));
		} else {
			memset (new_handler->id.mask, 0xFF,
				sizeof (new_handler->id.mask));
		}
		memset (new_handler->id.userid, 0x00,
			sizeof (new_handler->id.userid));
	}
	/* fill in the rest of handler */
	new_handler->pgm_data = pgm_data;
	new_handler->interrupt_table = ops;

	/*
	 * Check if someone else is registered with same pgmname, userid
	 * and mask. If someone is already registered with same pgmname,
	 * userid and mask, registration will fail and NULL will be returned
	 * to the application.
	 * If identical handler not found, then handler is added to list.
	 */
	rc = iucv_add_handler(new_handler);
	if (rc) {
		printk(KERN_WARNING "%s: Someone already registered with same "
		       "pgmname, userid, pgmmask\n", __FUNCTION__);
		kfree (new_handler);
		return NULL;
	}

	rc = iucv_declare_buffer();
	if (rc) {
		char *err = "Unknown";
		iucv_remove_handler(new_handler);
		kfree(new_handler);
		switch(rc) {
		case 0x03:
			err = "Directory error";
			break;
		case 0x0a:
			err = "Invalid length";
			break;
		case 0x13:
			err = "Buffer already exists";
			break;
		case 0x3e:
			err = "Buffer overlap";
			break;
		case 0x5c:
			err = "Paging or storage error";
			break;
		}
		printk(KERN_WARNING "%s: iucv_declare_buffer "
		       "returned error 0x%02lx (%s)\n", __FUNCTION__, rc, err);
		return NULL;
	}
	if (!register_flag) {
		/* request the 0x4000 external interrupt */
		rc = register_external_interrupt (0x4000, iucv_irq_handler);
		if (rc) {
			iucv_remove_handler(new_handler);
			kfree (new_handler);
			printk(KERN_WARNING "%s: "
			       "register_external_interrupt returned %ld\n",
			       __FUNCTION__, rc);
			return NULL;

		}
		register_flag = 1;
	}
	iucv_debug(1, "exiting");
	return new_handler;
}				/* end of register function */

/**
 * iucv_unregister_program:
 * @handle: address of handler
 *
 * Unregister application with IUCV.
 * Returns:
 *   0 on success, -EINVAL, if specified handle is invalid.
 */

int
iucv_unregister_program (iucv_handle_t handle)
{
	handler *h = NULL;
	struct list_head *lh;
	int i;
	ulong flags;

	iucv_debug(1, "entering");
	iucv_debug(1, "address of handler is %p", h);

	/* Checking if handle is valid  */
	spin_lock_irqsave (&iucv_lock, flags);
	list_for_each(lh, &iucv_handler_table) {
		if ((handler *)handle == list_entry(lh, handler, list)) {
			h = (handler *)handle;
			break;
		}
	}
	if (!h) {
		spin_unlock_irqrestore (&iucv_lock, flags);
		if (handle)
			printk(KERN_WARNING
			       "%s: Handler not found in iucv_handler_table.\n",
			       __FUNCTION__);
		else
			printk(KERN_WARNING
			       "%s: NULL handle passed by application.\n",
			       __FUNCTION__);
		return -EINVAL;
	}

	/**
	 * First, walk thru iucv_pathid_table and sever any pathid which is
	 * still pointing to the handler to be removed.
	 */
	for (i = 0; i < max_connections; i++)
		if (iucv_pathid_table[i] == h) {
			spin_unlock_irqrestore (&iucv_lock, flags);
			iucv_sever(i, h->id.user_data);
			spin_lock_irqsave(&iucv_lock, flags);
		}
	spin_unlock_irqrestore (&iucv_lock, flags);

	iucv_remove_handler(h);
	kfree(h);

	iucv_debug(1, "exiting");