Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756251AbYK0Kkp (ORCPT ); Thu, 27 Nov 2008 05:40:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753483AbYK0Kc5 (ORCPT ); Thu, 27 Nov 2008 05:32:57 -0500 Received: from mtagate6.de.ibm.com ([195.212.29.155]:47264 "EHLO mtagate6.de.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752019AbYK0KcW (ORCPT ); Thu, 27 Nov 2008 05:32:22 -0500 Message-Id: <20081127103133.367502008@de.ibm.com> References: <20081127103020.528516828@de.ibm.com> User-Agent: quilt/0.46-1 Date: Thu, 27 Nov 2008 11:30:40 +0100 From: Martin Schwidefsky To: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org Cc: Heiko Carstens , Hendrik Brueckner Subject: [patch 20/60] iucv: Locking free version of iucv_message_(receive|send) Content-Disposition: inline; filename=119-iucv-lockfree.diff Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9971 Lines: 310 From: Hendrik Brueckner 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 --- include/net/iucv/iucv.h | 45 ++++++++++++++ net/iucv/iucv.c | 152 ++++++++++++++++++++++++++++++++++++------------ 2 files changed, 161 insertions(+), 36 deletions(-) Index: quilt-2.6/include/net/iucv/iucv.h =================================================================== --- quilt-2.6.orig/include/net/iucv/iucv.h +++ quilt-2.6/include/net/iucv/iucv.h @@ -337,12 +337,35 @@ int iucv_message_purge(struct iucv_path * 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 * @msg: address of iucv msg structure @@ -386,12 +409,34 @@ int iucv_message_reply(struct iucv_path * 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 * @msg: address of iucv msg structure Index: quilt-2.6/net/iucv/iucv.c =================================================================== --- quilt-2.6.orig/net/iucv/iucv.c +++ quilt-2.6/net/iucv/iucv.c @@ -957,7 +957,52 @@ int iucv_message_purge(struct iucv_path 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) @@ -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; @@ -1022,6 +1042,37 @@ int iucv_message_receive(struct iucv_pat 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 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 * 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; } -- blue skies, Martin. "Reality continues to ruin my life." - Calvin. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/