From patchwork Mon Jul 10 01:31:04 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cyril Bur X-Patchwork-Id: 785993 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3x5SbJ109cz9s7m for ; Mon, 10 Jul 2017 11:40:44 +1000 (AEST) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3x5SbH703lzDqRM for ; Mon, 10 Jul 2017 11:40:43 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3x5SNm5MjhzDq6Q for ; Mon, 10 Jul 2017 11:31:36 +1000 (AEST) Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v6A1SgJH115279 for ; Sun, 9 Jul 2017 21:31:34 -0400 Received: from e23smtp03.au.ibm.com (e23smtp03.au.ibm.com [202.81.31.145]) by mx0a-001b2d01.pphosted.com with ESMTP id 2bjvs27uxm-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Sun, 09 Jul 2017 21:31:34 -0400 Received: from localhost by e23smtp03.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 10 Jul 2017 11:31:31 +1000 Received: from d23relay09.au.ibm.com (202.81.31.228) by e23smtp03.au.ibm.com (202.81.31.209) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Mon, 10 Jul 2017 11:31:29 +1000 Received: from d23av06.au.ibm.com (d23av06.au.ibm.com [9.190.235.151]) by d23relay09.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v6A1VTIU12648592 for ; Mon, 10 Jul 2017 11:31:29 +1000 Received: from d23av06.au.ibm.com (localhost [127.0.0.1]) by d23av06.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id v6A1VRo9030320 for ; Mon, 10 Jul 2017 11:31:28 +1000 Received: from ozlabs.au.ibm.com (ozlabs.au.ibm.com [9.192.253.14]) by d23av06.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id v6A1VR0N030304; Mon, 10 Jul 2017 11:31:27 +1000 Received: from camb691.ozlabs.ibm.com (haven.au.ibm.com [9.192.254.114]) (using TLSv1.2 with cipher DHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ozlabs.au.ibm.com (Postfix) with ESMTPSA id 629A5A0388; Mon, 10 Jul 2017 11:31:27 +1000 (AEST) From: Cyril Bur To: linuxppc-dev@lists.ozlabs.org, linux-mtd@lists.infradead.org Subject: [PATCH v2 08/10] powerpc/opal: Add opal_async_wait_response_interruptible() to opal-async Date: Mon, 10 Jul 2017 11:31:04 +1000 X-Mailer: git-send-email 2.13.2 In-Reply-To: <20170710013106.27276-1-cyrilbur@gmail.com> References: <20170710013106.27276-1-cyrilbur@gmail.com> X-TM-AS-MML: disable x-cbid: 17071001-0008-0000-0000-0000014E9A31 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17071001-0009-0000-0000-0000097EE9DD Message-Id: <20170710013106.27276-9-cyrilbur@gmail.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-07-09_14:, , 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-1707100024 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: stewart@linux.vnet.ibm.com, alistair@popple.id.au, dwmw2@infradead.org, rlippert@google.com Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" This patch adds an _interruptible version of opal_async_wait_response(). This is useful when a long running OPAL call is performed on behalf of a userspace thread, for example, the opal_flash_{read,write,erase} functions performed by the powernv-flash MTD driver. It is foreseeable that these functions would take upwards of two minutes causing the wait_event() to block long enough to cause hung task warnings. Furthermore, wait_event_interruptible() is preferable as otherwise there is no way for signals to stop the process which is going to be confusing in userspace. Signed-off-by: Cyril Bur --- arch/powerpc/include/asm/opal.h | 2 + arch/powerpc/platforms/powernv/opal-async.c | 87 +++++++++++++++++++++++++++-- 2 files changed, 85 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h index 5553ad2f3e53..6e9e53d744f3 100644 --- a/arch/powerpc/include/asm/opal.h +++ b/arch/powerpc/include/asm/opal.h @@ -294,6 +294,8 @@ extern void opal_notifier_update_evt(uint64_t evt_mask, uint64_t evt_val); extern int opal_async_get_token_interruptible(void); extern int opal_async_release_token(int token); extern int opal_async_wait_response(uint64_t token, struct opal_msg *msg); +extern int opal_async_wait_response_interruptible(uint64_t token, + struct opal_msg *msg); extern int opal_get_sensor_data(u32 sensor_hndl, u32 *sensor_data); struct rtc_time; diff --git a/arch/powerpc/platforms/powernv/opal-async.c b/arch/powerpc/platforms/powernv/opal-async.c index d692372a0363..f6b30cfceb8f 100644 --- a/arch/powerpc/platforms/powernv/opal-async.c +++ b/arch/powerpc/platforms/powernv/opal-async.c @@ -26,6 +26,8 @@ enum opal_async_token_state { ASYNC_TOKEN_FREE, ASYNC_TOKEN_ALLOCATED, + ASYNC_TOKEN_DISPATCHED, + ASYNC_TOKEN_ABANDONED, ASYNC_TOKEN_COMPLETED }; @@ -59,8 +61,10 @@ static int __opal_async_get_token(void) } /* - * Note: If the returned token is used in an opal call and opal returns - * OPAL_ASYNC_COMPLETION you MUST opal_async_wait_response() before + * Note: If the returned token is used in an opal call and opal + * returns OPAL_ASYNC_COMPLETION you MUST one of + * opal_async_wait_response() or + * opal_async_wait_response_interruptible() at least once before * calling another other opal_async_* function */ int opal_async_get_token_interruptible(void) @@ -97,6 +101,16 @@ static int __opal_async_release_token(int token) opal_async_tokens[token].state = ASYNC_TOKEN_FREE; rc = 0; break; + /* + * DISPATCHED and ABANDONED tokens must wait for OPAL to + * respond. + * Mark a DISPATCHED token as ABANDONED so that the response + * response handling code knows no one cares and that it can + * free it then. + */ + case ASYNC_TOKEN_DISPATCHED: + opal_async_tokens[token].state = ASYNC_TOKEN_ABANDONED; + /* Fall through */ default: rc = 1; } @@ -129,7 +143,11 @@ int opal_async_wait_response(uint64_t token, struct opal_msg *msg) return -EINVAL; } - /* Wakeup the poller before we wait for events to speed things + /* + * There is no need to mark the token as dispatched, wait_event() + * will block until the token completes. + * + * Wakeup the poller before we wait for events to speed things * up on platforms or simulators where the interrupts aren't * functional. */ @@ -142,11 +160,66 @@ int opal_async_wait_response(uint64_t token, struct opal_msg *msg) } EXPORT_SYMBOL_GPL(opal_async_wait_response); +int opal_async_wait_response_interruptible(uint64_t token, struct opal_msg *msg) +{ + unsigned long flags; + int ret; + + if (token >= opal_max_async_tokens) { + pr_err("%s: Invalid token passed\n", __func__); + return -EINVAL; + } + + if (!msg) { + pr_err("%s: Invalid message pointer passed\n", __func__); + return -EINVAL; + } + + /* + * The first time this gets called we mark the token as DISPATCHED + * so that if wait_event_interruptible() returns not zero and the + * caller frees the token, we know not to actually free the token + * until the response comes. + * + * Only change if the token is ALLOCATED - it may have been + * completed even before the caller gets around to calling this + * the first time. + * + * There is also a dirty great comment at the token allocation + * function that if the opal call returns OPAL_ASYNC_COMPLETION to + * the caller then the caller *must* call this or the not + * interruptible version before doing anything else with the + * token. + */ + if (opal_async_tokens[token].state == ASYNC_TOKEN_ALLOCATED) { + spin_lock_irqsave(&opal_async_comp_lock, flags); + if (opal_async_tokens[token].state == ASYNC_TOKEN_ALLOCATED) + opal_async_tokens[token].state = ASYNC_TOKEN_DISPATCHED; + spin_unlock_irqrestore(&opal_async_comp_lock, flags); + } + + /* + * Wakeup the poller before we wait for events to speed things + * up on platforms or simulators where the interrupts aren't + * functional. + */ + opal_wake_poller(); + ret = wait_event_interruptible(opal_async_wait, + opal_async_tokens[token].state == + ASYNC_TOKEN_COMPLETED); + if (!ret) + memcpy(msg, &opal_async_tokens[token].response, sizeof(*msg)); + + return ret; +} +EXPORT_SYMBOL_GPL(opal_async_wait_response_interruptible); + /* Called from interrupt context */ static int opal_async_comp_event(struct notifier_block *nb, unsigned long msg_type, void *msg) { struct opal_msg *comp_msg = msg; + enum opal_async_token_state state; unsigned long flags; uint64_t token; @@ -154,11 +227,17 @@ static int opal_async_comp_event(struct notifier_block *nb, return 0; token = be64_to_cpu(comp_msg->params[0]); - memcpy(&opal_async_tokens[token].response, comp_msg, sizeof(*comp_msg)); spin_lock_irqsave(&opal_async_comp_lock, flags); + state = opal_async_tokens[token].state; opal_async_tokens[token].state = ASYNC_TOKEN_COMPLETED; spin_unlock_irqrestore(&opal_async_comp_lock, flags); + if (state == ASYNC_TOKEN_ABANDONED) { + /* Free the token, no one else will */ + opal_async_release_token(token); + return 0; + } + memcpy(&opal_async_tokens[token].response, comp_msg, sizeof(*comp_msg)); wake_up(&opal_async_wait); return 0;