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 3x6m6Y3Y3WzDqjc for ; Wed, 12 Jul 2017 14:23:49 +1000 (AEST) Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v6C4NjlU064597 for ; Wed, 12 Jul 2017 00:23:46 -0400 Received: from e23smtp07.au.ibm.com (e23smtp07.au.ibm.com [202.81.31.140]) by mx0a-001b2d01.pphosted.com with ESMTP id 2bncjar8ff-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 12 Jul 2017 00:23:45 -0400 Received: from localhost by e23smtp07.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 12 Jul 2017 14:23:36 +1000 Received: from d23av03.au.ibm.com (d23av03.au.ibm.com [9.190.234.97]) by d23relay10.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v6C4NV8624772770 for ; Wed, 12 Jul 2017 14:23:31 +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 v6C4NMHe002109 for ; Wed, 12 Jul 2017 14:23:23 +1000 From: Cyril Bur To: linuxppc-dev@lists.ozlabs.org, linux-mtd@lists.infradead.org Cc: benh@kernel.crashing.org, stewart@linux.vnet.ibm.com, dwmw2@infradead.org, rlippert@google.com, alistair@popple.id.au Subject: [PATCH v3 02/10] mtd: powernv_flash: Lock around concurrent access to OPAL Date: Wed, 12 Jul 2017 14:22:56 +1000 In-Reply-To: <20170712042304.19745-1-cyrilbur@gmail.com> References: <20170712042304.19745-1-cyrilbur@gmail.com> Message-Id: <20170712042304.19745-3-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 --- 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); /* -- 2.13.2