From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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 3wjHbv6Rf5zDqLV for ; Wed, 7 Jun 2017 15:46:19 +1000 (AEST) Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v575j4nw108624 for ; Wed, 7 Jun 2017 01:46:17 -0400 Received: from e23smtp01.au.ibm.com (e23smtp01.au.ibm.com [202.81.31.143]) by mx0a-001b2d01.pphosted.com with ESMTP id 2ax6nyshr3-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 07 Jun 2017 01:46:17 -0400 Received: from localhost by e23smtp01.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 7 Jun 2017 15:46:15 +1000 Received: from d23av03.au.ibm.com (d23av03.au.ibm.com [9.190.234.97]) by d23relay06.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v575k4GT66846954 for ; Wed, 7 Jun 2017 15:46:12 +1000 Received: from d23av03.au.ibm.com (localhost [127.0.0.1]) by d23av03.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id v575jW11026296 for ; Wed, 7 Jun 2017 15:45:32 +1000 From: Cyril Bur To: dwmw2@infradead.org, computersforpeace@gmail.com, mpe@ellerman.id.au Cc: linux-mtd@lists.infradead.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH 2/2] mtd: powernv_flash: Lock around concurrent access to OPAL Date: Wed, 7 Jun 2017 15:43:55 +1000 In-Reply-To: <20170607054355.10590-1-cyrilbur@gmail.com> References: <20170607054355.10590-1-cyrilbur@gmail.com> Message-Id: <20170607054355.10590-2-cyrilbur@gmail.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , OPAL can only manage one flash access at a time and will return an OPAL_BUSY error for each concurrent access to the flash. The simplest way to prevent this from happening is with a mutex. Signed-off-by: Cyril Bur --- This is to address https://github.com/open-power/skiboot/issues/80 drivers/mtd/devices/powernv_flash.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/mtd/devices/powernv_flash.c b/drivers/mtd/devices/powernv_flash.c index a9a20c00687c..7b41af06f4fe 100644 --- a/drivers/mtd/devices/powernv_flash.c +++ b/drivers/mtd/devices/powernv_flash.c @@ -38,6 +38,7 @@ struct powernv_flash { struct mtd_info mtd; + struct mutex lock; u32 id; }; @@ -59,12 +60,15 @@ static int powernv_flash_async_op(struct mtd_info *mtd, enum flash_op op, dev_dbg(dev, "%s(op=%d, offset=0x%llx, len=%zu)\n", __func__, op, offset, len); + mutex_lock(&info->lock); + token = opal_async_get_token_interruptible(); if (token < 0) { if (token != -ERESTARTSYS) dev_err(dev, "Failed to get an async token\n"); - return token; + rc = token; + goto out; } switch (op) { @@ -79,18 +83,21 @@ static int powernv_flash_async_op(struct mtd_info *mtd, enum flash_op op, break; default: WARN_ON_ONCE(1); - return -EIO; + rc = -EIO; + goto out; } if (rc != OPAL_ASYNC_COMPLETION) { dev_err(dev, "opal_flash_async_op(op=%d) failed (rc %d)\n", op, rc); opal_async_release_token(token); - return -EIO; + rc = -EIO; + goto out; } rc = opal_async_wait_response(token, &msg); opal_async_release_token(token); + mutex_unlock(&info->lock); if (rc) { dev_err(dev, "opal async wait failed (rc %d)\n", rc); return -EIO; @@ -106,6 +113,9 @@ static int powernv_flash_async_op(struct mtd_info *mtd, enum flash_op op, } return rc; +out: + mutex_unlock(&info->lock); + return rc; } /** @@ -237,6 +247,8 @@ static int powernv_flash_probe(struct platform_device *pdev) if (ret) goto out; + mutex_init(&data->lock); + dev_set_drvdata(dev, data); /* -- 2.13.0