From patchwork Tue Oct 10 03:33:00 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cyril Bur X-Patchwork-Id: 823683 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 3yB2sF3tmbz9s4q for ; Tue, 10 Oct 2017 14:38:57 +1100 (AEDT) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3yB2sF30YjzDr5W for ; Tue, 10 Oct 2017 14:38:57 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: ozlabs.org; spf=softfail (mailfrom) smtp.mailfrom=gmail.com (client-ip=148.163.156.1; helo=mx0a-001b2d01.pphosted.com; envelope-from=cyrilbur@gmail.com; receiver=) Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (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 3yB2kz2YyWzDr55 for ; Tue, 10 Oct 2017 14:33:30 +1100 (AEDT) Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v9A3TJoq017159 for ; Mon, 9 Oct 2017 23:33:28 -0400 Received: from e06smtp10.uk.ibm.com (e06smtp10.uk.ibm.com [195.75.94.106]) by mx0a-001b2d01.pphosted.com with ESMTP id 2dgmde532w-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 09 Oct 2017 23:33:28 -0400 Received: from localhost by e06smtp10.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Tue, 10 Oct 2017 04:33:25 +0100 Received: from d23av06.au.ibm.com (d23av06.au.ibm.com [9.190.235.151]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v9A3XNCR18153608 for ; Tue, 10 Oct 2017 03:33:24 GMT 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 v9A3XMqh010370 for ; Tue, 10 Oct 2017 14:33:23 +1100 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 v9A3XMJd010366; Tue, 10 Oct 2017 14:33:22 +1100 Received: from camb691.au.ibm.com (camb691.au.ibm.com [9.192.250.228]) (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 B3274A037F; Tue, 10 Oct 2017 14:33:21 +1100 (AEDT) From: Cyril Bur To: linux-mtd@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, stewart@linux.vnet.ibm.com Subject: [PATCH v4 08/10] powerpc/opal: Add opal_async_wait_response_interruptible() to opal-async Date: Tue, 10 Oct 2017 14:33:00 +1100 X-Mailer: git-send-email 2.14.2 In-Reply-To: <20171010033302.20854-1-cyrilbur@gmail.com> References: <20171010033302.20854-1-cyrilbur@gmail.com> X-TM-AS-MML: disable x-cbid: 17101003-0040-0000-0000-000003E1237C X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17101003-0041-0000-0000-000025E3253D Message-Id: <20171010033302.20854-9-cyrilbur@gmail.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-10-09_07:, , 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=8.0.1-1707230000 definitions=main-1710100050 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.24 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: boris.brezillon@free-electrons.com, computersforpeace@gmail.com, dwmw2@infradead.org, sjitindarsingh@gmail.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 0078eb5acf98..f95ca4560bfa 100644 --- a/arch/powerpc/include/asm/opal.h +++ b/arch/powerpc/include/asm/opal.h @@ -307,6 +307,8 @@ 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 fbae8a37ce2c..e2004606b75b 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_UNALLOCATED = 0, ASYNC_TOKEN_ALLOCATED, + ASYNC_TOKEN_DISPATCHED, + ASYNC_TOKEN_ABANDONED, ASYNC_TOKEN_COMPLETED }; @@ -58,8 +60,10 @@ 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) @@ -96,6 +100,16 @@ static int __opal_async_release_token(int token) opal_async_tokens[token].state = ASYNC_TOKEN_UNALLOCATED; 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; } @@ -128,7 +142,11 @@ 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. */ @@ -141,11 +159,66 @@ 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; @@ -153,11 +226,17 @@ 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;