Skip to content

Commit

Permalink
[S390] iucv: Locking free version of iucv_message_(receive|send)
Browse files Browse the repository at this point in the history 
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: Hendrik Brueckner <[email protected]>
  • Loading branch information
@hbrueckner
hbrueckner authored and Martin Schwidefsky committed Dec 25, 2008
1 parent 44a01d5 commit 91d5d45
Show file tree
Hide file tree
Showing 2 changed files with 161 additions and 36 deletions.
45 changes: 45 additions & 0 deletions include/net/iucv/iucv.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down Expand Up @@ -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
Expand Down
152 changes: 116 additions & 36 deletions net/iucv/iucv.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -957,7 +957,52 @@ 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)
* @buffer: address of data buffer or address of struct iucv_array
* @size: length of data buffer
* @residual:
*
* Internal function used by iucv_message_receive and __iucv_message_receive
* to receive RMDATA data stored in struct iucv_message.
*/
static int iucv_message_receive_iprmdata(struct iucv_path *path,
struct iucv_message *msg,
u8 flags, void *buffer,
size_t size, size_t *residual)
{
struct iucv_array *array;
u8 *rmmsg;
size_t copy;

/*
* Message is 8 bytes long and has been stored to the
* message descriptor itself.
*/
if (residual)
*residual = abs(size - 8);
rmmsg = msg->rmmsg;
if (flags & IUCV_IPBUFLST) {
/* Copy to struct iucv_array. */
size = (size < 8) ? size : 8;
for (array = buffer; size > 0; array++) {
copy = min_t(size_t, size, array->length);
memcpy((u8 *)(addr_t) array->address,
rmmsg, copy);
rmmsg += copy;
size -= copy;
}
} else {
/* Copy to direct buffer. */
memcpy(buffer, rmmsg, min_t(size_t, size, 8));
}
return 0;
}

/**
* __iucv_message_receive
* @path: address of iucv path structure
* @msg: address of iucv msg structure
* @flags: how the message is received (IUCV_IPBUFLST)
Expand All @@ -969,44 +1014,19 @@ EXPORT_SYMBOL(iucv_message_purge);
* 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)
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;
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;
if (flags & IUCV_IPBUFLST) {
/* Copy to struct iucv_array. */
size = (size < 8) ? size : 8;
for (array = buffer; size > 0; array++) {
copy = min_t(size_t, size, array->length);
memcpy((u8 *)(addr_t) array->address,
rmmsg, copy);
rmmsg += copy;
size -= copy;
}
} else {
/* Copy to direct buffer. */
memcpy(buffer, rmmsg, min_t(size_t, size, 8));
}
return 0;
}

local_bh_disable();
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;
Expand All @@ -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;
}
Expand Down Expand Up @@ -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)
Expand All @@ -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) {
Expand All @@ -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;
}
Expand Down

0 comments on commit 91d5d45

Please sign in to comment.