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Commit 91d5d45e authored by Hendrik Brueckner's avatar Hendrik Brueckner Committed by Martin Schwidefsky
Browse files

[S390] iucv: Locking free version of iucv_message_(receive|send) 



Provide a locking free version of iucv_message_receive and iucv_message_send
that do not call local_bh_enable in a spin_lock_(bh|irqsave)() context.

Signed-off-by: default avatarHendrik Brueckner <brueckner@linux.vnet.ibm.com>
parent 44a01d5b

include/net/iucv/iucv.h

+45 −0
Original line number Diff line number Diff line
@@ -337,11 +337,34 @@ int iucv_message_purge(struct iucv_path *path, struct iucv_message *msg, 
 * established paths. This function will deal with RMDATA messages

 * embedded in struct iucv_message as well.

 *

 * Locking:	local_bh_enable/local_bh_disable

 *

 * Returns the result from the CP IUCV call.

 */

int iucv_message_receive(struct iucv_path *path, struct iucv_message *msg,

			 u8 flags, void *buffer, size_t size, size_t *residual);



/**

 * __iucv_message_receive

 * @path: address of iucv path structure

 * @msg: address of iucv msg structure

 * @flags: flags that affect how the message is received (IUCV_IPBUFLST)

 * @buffer: address of data buffer or address of struct iucv_array

 * @size: length of data buffer

 * @residual:

 *

 * This function receives messages that are being sent to you over

 * established paths. This function will deal with RMDATA messages

 * embedded in struct iucv_message as well.

 *

 * Locking:	no locking.

 *

 * Returns the result from the CP IUCV call.

 */

int __iucv_message_receive(struct iucv_path *path, struct iucv_message *msg,

			   u8 flags, void *buffer, size_t size,

			   size_t *residual);



/**

 * iucv_message_reject

 * @path: address of iucv path structure
@@ -386,11 +409,33 @@ int iucv_message_reply(struct iucv_path *path, struct iucv_message *msg, 
 * transmitted is in a buffer and this is a one-way message and the

 * receiver will not reply to the message.

 *

 * Locking:	local_bh_enable/local_bh_disable

 *

 * Returns the result from the CP IUCV call.

 */

int iucv_message_send(struct iucv_path *path, struct iucv_message *msg,

		      u8 flags, u32 srccls, void *buffer, size_t size);



/**

 * __iucv_message_send

 * @path: address of iucv path structure

 * @msg: address of iucv msg structure

 * @flags: how the message is sent (IUCV_IPRMDATA, IUCV_IPPRTY, IUCV_IPBUFLST)

 * @srccls: source class of message

 * @buffer: address of data buffer or address of struct iucv_array

 * @size: length of send buffer

 *

 * This function transmits data to another application. Data to be

 * transmitted is in a buffer and this is a one-way message and the

 * receiver will not reply to the message.

 *

 * Locking:	no locking.

 *

 * Returns the result from the CP IUCV call.

 */

int __iucv_message_send(struct iucv_path *path, struct iucv_message *msg,

			u8 flags, u32 srccls, void *buffer, size_t size);



/**

 * iucv_message_send2way

 * @path: address of iucv path structure

net/iucv/iucv.c

+116 −36
Original line number Diff line number Diff line
@@ -957,7 +957,7 @@ int iucv_message_purge(struct iucv_path *path, struct iucv_message *msg, 
EXPORT_SYMBOL(iucv_message_purge);



/**

 * iucv_message_receive

 * iucv_message_receive_iprmdata

 * @path: address of iucv path structure

 * @msg: address of iucv msg structure

 * @flags: how the message is received (IUCV_IPBUFLST)
@@ -965,27 +965,22 @@ EXPORT_SYMBOL(iucv_message_purge); 
 * @size: length of data buffer

 * @residual:

 *

 * This function receives messages that are being sent to you over

 * established paths. This function will deal with RMDATA messages

 * embedded in struct iucv_message as well.

 *

 * Returns the result from the CP IUCV call.

 * Internal function used by iucv_message_receive and __iucv_message_receive

 * to receive RMDATA data stored in struct iucv_message.

 */

int iucv_message_receive(struct iucv_path *path, struct iucv_message *msg,

			 u8 flags, void *buffer, size_t size, size_t *residual)

static int iucv_message_receive_iprmdata(struct iucv_path *path,

					 struct iucv_message *msg,

					 u8 flags, void *buffer,

					 size_t size, size_t *residual)

{

	union iucv_param *parm;

	struct iucv_array *array;

	u8 *rmmsg;

	size_t copy;

	int rc;



	if (msg->flags & IUCV_IPRMDATA) {

	/*

	 * Message is 8 bytes long and has been stored to the

	 * message descriptor itself.

	 */

		rc = (size < 8) ? 5 : 0;

	if (residual)

		*residual = abs(size - 8);

	rmmsg = msg->rmmsg;
@@ -1006,7 +1001,32 @@ int iucv_message_receive(struct iucv_path *path, struct iucv_message *msg, 
	return 0;

}



	local_bh_disable();

/**

 * __iucv_message_receive

 * @path: address of iucv path structure

 * @msg: address of iucv msg structure

 * @flags: how the message is received (IUCV_IPBUFLST)

 * @buffer: address of data buffer or address of struct iucv_array

 * @size: length of data buffer

 * @residual:

 *

 * This function receives messages that are being sent to you over

 * established paths. This function will deal with RMDATA messages

 * embedded in struct iucv_message as well.

 *

 * Locking:	no locking

 *

 * Returns the result from the CP IUCV call.

 */

int __iucv_message_receive(struct iucv_path *path, struct iucv_message *msg,

			   u8 flags, void *buffer, size_t size, size_t *residual)

{

	union iucv_param *parm;

	int rc;



	if (msg->flags & IUCV_IPRMDATA)

		return iucv_message_receive_iprmdata(path, msg, flags,

						     buffer, size, residual);

	parm = iucv_param[smp_processor_id()];

	memset(parm, 0, sizeof(union iucv_param));

	parm->db.ipbfadr1 = (u32)(addr_t) buffer;
@@ -1022,6 +1042,37 @@ int iucv_message_receive(struct iucv_path *path, struct iucv_message *msg, 
		if (residual)

			*residual = parm->db.ipbfln1f;

	}

	return rc;

}

EXPORT_SYMBOL(__iucv_message_receive);



/**

 * iucv_message_receive

 * @path: address of iucv path structure

 * @msg: address of iucv msg structure

 * @flags: how the message is received (IUCV_IPBUFLST)

 * @buffer: address of data buffer or address of struct iucv_array

 * @size: length of data buffer

 * @residual:

 *

 * This function receives messages that are being sent to you over

 * established paths. This function will deal with RMDATA messages

 * embedded in struct iucv_message as well.

 *

 * Locking:	local_bh_enable/local_bh_disable

 *

 * Returns the result from the CP IUCV call.

 */

int iucv_message_receive(struct iucv_path *path, struct iucv_message *msg,

			 u8 flags, void *buffer, size_t size, size_t *residual)

{

	int rc;



	if (msg->flags & IUCV_IPRMDATA)

		return iucv_message_receive_iprmdata(path, msg, flags,

						     buffer, size, residual);

	local_bh_disable();

	rc = __iucv_message_receive(path, msg, flags, buffer, size, residual);

	local_bh_enable();

	return rc;

}
@@ -1101,7 +1152,7 @@ int iucv_message_reply(struct iucv_path *path, struct iucv_message *msg, 
EXPORT_SYMBOL(iucv_message_reply);



/**

 * iucv_message_send

 * __iucv_message_send

 * @path: address of iucv path structure

 * @msg: address of iucv msg structure

 * @flags: how the message is sent (IUCV_IPRMDATA, IUCV_IPPRTY, IUCV_IPBUFLST)
@@ -1113,15 +1164,16 @@ EXPORT_SYMBOL(iucv_message_reply); 
 * transmitted is in a buffer and this is a one-way message and the

 * receiver will not reply to the message.

 *

 * Locking:	no locking

 *

 * Returns the result from the CP IUCV call.

 */

int iucv_message_send(struct iucv_path *path, struct iucv_message *msg,

int __iucv_message_send(struct iucv_path *path, struct iucv_message *msg,

		      u8 flags, u32 srccls, void *buffer, size_t size)

{

	union iucv_param *parm;

	int rc;



	local_bh_disable();

	parm = iucv_param[smp_processor_id()];

	memset(parm, 0, sizeof(union iucv_param));

	if (flags & IUCV_IPRMDATA) {
@@ -1144,6 +1196,34 @@ int iucv_message_send(struct iucv_path *path, struct iucv_message *msg, 
	rc = iucv_call_b2f0(IUCV_SEND, parm);

	if (!rc)

		msg->id = parm->db.ipmsgid;

	return rc;

}

EXPORT_SYMBOL(__iucv_message_send);



/**

 * iucv_message_send

 * @path: address of iucv path structure

 * @msg: address of iucv msg structure

 * @flags: how the message is sent (IUCV_IPRMDATA, IUCV_IPPRTY, IUCV_IPBUFLST)

 * @srccls: source class of message

 * @buffer: address of send buffer or address of struct iucv_array

 * @size: length of send buffer

 *

 * This function transmits data to another application. Data to be

 * transmitted is in a buffer and this is a one-way message and the

 * receiver will not reply to the message.

 *

 * Locking:	local_bh_enable/local_bh_disable

 *

 * Returns the result from the CP IUCV call.

 */

int iucv_message_send(struct iucv_path *path, struct iucv_message *msg,

		      u8 flags, u32 srccls, void *buffer, size_t size)

{

	int rc;



	local_bh_disable();

	rc = __iucv_message_send(path, msg, flags, srccls, buffer, size);

	local_bh_enable();

	return rc;

}