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Violators will be prosecuted for from ; Wed, 21 Jun 2017 22:14:34 -0400 Received: from b01cxnp22036.gho.pok.ibm.com (9.57.198.26) by e12.ny.us.ibm.com (146.89.104.199) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Wed, 21 Jun 2017 22:14:32 -0400 Received: from b01ledav006.gho.pok.ibm.com (b01ledav006.gho.pok.ibm.com [9.57.199.111]) by b01cxnp22036.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v5M2EMas62849110; Thu, 22 Jun 2017 02:14:22 GMT Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 020A5AC048; Wed, 21 Jun 2017 22:14:23 -0400 (EDT) Received: from p8tul1-build.aus.stglabs.ibm.com (unknown [9.3.141.206]) by b01ledav006.gho.pok.ibm.com (Postfix) with ESMTP id 3BC97AC03F; Wed, 21 Jun 2017 22:14:22 -0400 (EDT) From: Uma Krishnan To: linux-scsi@vger.kernel.org, James Bottomley , "Martin K. Petersen" , "Matthew R. Ochs" , "Manoj N. Kumar" Cc: linuxppc-dev@lists.ozlabs.org, Ian Munsie , Andrew Donnellan , Frederic Barrat , Christophe Lombard Subject: [PATCH 04/17] cxlflash: Schedule asynchronous reset of the host Date: Wed, 21 Jun 2017 21:14:17 -0500 X-Mailer: git-send-email 2.1.0 In-Reply-To: <1498097563-8680-1-git-send-email-ukrishn@linux.vnet.ibm.com> References: <1498097563-8680-1-git-send-email-ukrishn@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17062202-0048-0000-0000-000001AE8F5A X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007269; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000214; SDB=6.00878072; UDB=6.00437482; IPR=6.00658212; BA=6.00005434; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00015913; XFM=3.00000015; UTC=2017-06-22 02:14:33 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17062202-0049-0000-0000-0000419BE754 Message-Id: <1498097657-8826-1-git-send-email-ukrishn@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-06-22_01:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=2 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1703280000 definitions=main-1706220037 Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP A context reset failure indicates the AFU is in a bad state. At present, when such a situation occurs, no further action is taken. This leaves the adapter in an unusable state with no recoverable actions. To avoid this situation, context reset failures will be escalated to a host reset operation. This will be done asynchronously to allow the acting thread to return to the user with a failure. Signed-off-by: Uma Krishnan Acked-by: Matthew R. Ochs --- drivers/scsi/cxlflash/common.h | 2 + drivers/scsi/cxlflash/main.c | 137 ++++++++++++++++++++++++++++++----------- 2 files changed, 104 insertions(+), 35 deletions(-) diff --git a/drivers/scsi/cxlflash/common.h b/drivers/scsi/cxlflash/common.h index 75decf6..e9b6108 100644 --- a/drivers/scsi/cxlflash/common.h +++ b/drivers/scsi/cxlflash/common.h @@ -15,6 +15,7 @@ #ifndef _CXLFLASH_COMMON_H #define _CXLFLASH_COMMON_H +#include #include #include #include @@ -144,6 +145,7 @@ struct cxlflash_cfg { bool tmf_active; wait_queue_head_t reset_waitq; enum cxlflash_state state; + async_cookie_t async_reset_cookie; }; struct afu_cmd { diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c index b8dc379..20c2c5e 100644 --- a/drivers/scsi/cxlflash/main.c +++ b/drivers/scsi/cxlflash/main.c @@ -586,6 +586,20 @@ static void free_mem(struct cxlflash_cfg *cfg) } /** + * cxlflash_reset_sync() - synchronizing point for asynchronous resets + * @cfg: Internal structure associated with the host. + */ +static void cxlflash_reset_sync(struct cxlflash_cfg *cfg) +{ + if (cfg->async_reset_cookie == 0) + return; + + /* Wait until all async calls prior to this cookie have completed */ + async_synchronize_cookie(cfg->async_reset_cookie + 1); + cfg->async_reset_cookie = 0; +} + +/** * stop_afu() - stops the AFU command timers and unmaps the MMIO space * @cfg: Internal structure associated with the host. * @@ -601,6 +615,8 @@ static void stop_afu(struct cxlflash_cfg *cfg) int i; cancel_work_sync(&cfg->work_q); + if (!current_is_async()) + cxlflash_reset_sync(cfg); if (likely(afu)) { while (atomic_read(&afu->cmds_active)) @@ -2005,6 +2021,91 @@ static int init_afu(struct cxlflash_cfg *cfg) } /** + * afu_reset() - resets the AFU + * @cfg: Internal structure associated with the host. + * + * Return: 0 on success, -errno on failure + */ +static int afu_reset(struct cxlflash_cfg *cfg) +{ + struct device *dev = &cfg->dev->dev; + int rc = 0; + + /* Stop the context before the reset. Since the context is + * no longer available restart it after the reset is complete + */ + term_afu(cfg); + + rc = init_afu(cfg); + + dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc); + return rc; +} + +/** + * drain_ioctls() - wait until all currently executing ioctls have completed + * @cfg: Internal structure associated with the host. + * + * Obtain write access to read/write semaphore that wraps ioctl + * handling to 'drain' ioctls currently executing. + */ +static void drain_ioctls(struct cxlflash_cfg *cfg) +{ + down_write(&cfg->ioctl_rwsem); + up_write(&cfg->ioctl_rwsem); +} + +/** + * cxlflash_async_reset_host() - asynchronous host reset handler + * @data: Private data provided while scheduling reset. + * @cookie: Cookie that can be used for checkpointing. + */ +static void cxlflash_async_reset_host(void *data, async_cookie_t cookie) +{ + struct cxlflash_cfg *cfg = data; + struct device *dev = &cfg->dev->dev; + int rc = 0; + + if (cfg->state != STATE_RESET) { + dev_dbg(dev, "%s: Not performing a reset, state=%d\n", + __func__, cfg->state); + goto out; + } + + drain_ioctls(cfg); + cxlflash_mark_contexts_error(cfg); + rc = afu_reset(cfg); + if (rc) + cfg->state = STATE_FAILTERM; + else + cfg->state = STATE_NORMAL; + wake_up_all(&cfg->reset_waitq); + +out: + scsi_unblock_requests(cfg->host); +} + +/** + * cxlflash_schedule_async_reset() - schedule an asynchronous host reset + * @cfg: Internal structure associated with the host. + */ +static void cxlflash_schedule_async_reset(struct cxlflash_cfg *cfg) +{ + struct device *dev = &cfg->dev->dev; + + if (cfg->state != STATE_NORMAL) { + dev_dbg(dev, "%s: Not performing reset state=%d\n", + __func__, cfg->state); + return; + } + + cfg->state = STATE_RESET; + scsi_block_requests(cfg->host); + cfg->async_reset_cookie = async_schedule(cxlflash_async_reset_host, + cfg); +} + +/** * cxlflash_afu_sync() - builds and sends an AFU sync command * @afu: AFU associated with the host. * @ctx_hndl_u: Identifies context requesting sync. @@ -2085,6 +2186,7 @@ int cxlflash_afu_sync(struct afu *afu, ctx_hndl_t ctx_hndl_u, rc = afu->context_reset(hwq); if (!rc && ++nretry < 2) goto retry; + cxlflash_schedule_async_reset(cfg); } out: @@ -2096,41 +2198,6 @@ int cxlflash_afu_sync(struct afu *afu, ctx_hndl_t ctx_hndl_u, } /** - * afu_reset() - resets the AFU - * @cfg: Internal structure associated with the host. - * - * Return: 0 on success, -errno on failure - */ -static int afu_reset(struct cxlflash_cfg *cfg) -{ - struct device *dev = &cfg->dev->dev; - int rc = 0; - - /* Stop the context before the reset. Since the context is - * no longer available restart it after the reset is complete - */ - term_afu(cfg); - - rc = init_afu(cfg); - - dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc); - return rc; -} - -/** - * drain_ioctls() - wait until all currently executing ioctls have completed - * @cfg: Internal structure associated with the host. - * - * Obtain write access to read/write semaphore that wraps ioctl - * handling to 'drain' ioctls currently executing. - */ -static void drain_ioctls(struct cxlflash_cfg *cfg) -{ - down_write(&cfg->ioctl_rwsem); - up_write(&cfg->ioctl_rwsem); -} - -/** * cxlflash_eh_device_reset_handler() - reset a single LUN * @scp: SCSI command to send. *