From patchwork Mon Jan 31 21:51:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Nyekjaer X-Patchwork-Id: 538658 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9785FC433EF for ; Mon, 31 Jan 2022 21:51:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351284AbiAaVvr (ORCPT ); Mon, 31 Jan 2022 16:51:47 -0500 Received: from first.geanix.com ([116.203.34.67]:37720 "EHLO first.geanix.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345541AbiAaVvr (ORCPT ); Mon, 31 Jan 2022 16:51:47 -0500 Received: from zen.. (unknown [185.17.218.86]) by first.geanix.com (Postfix) with ESMTPSA id 63061126B7D; Mon, 31 Jan 2022 21:51:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=geanix.com; s=first; t=1643665904; bh=iIJNpft2xL+n2vE0wSgEc/ganWtCw9JUh/zcBq4c1so=; h=From:To:Cc:Subject:Date; b=BpCK9Qn/VAPuo+A4mc1RLxUpVtffpFFJElctH9OSnBdLu5FLSY4JqZPA0sqjMPszx tdSv2KU5a+KkHjqA7zzV3h6LbZi8LvHqQBNm2Dywa3vRzAJM1Fxh4hEEEHAt/pXwHK Zi3y9Mcyu6JN2PUzfSkCmzOjgnPg6Zuusz3qRJi75FGm/n5cB5yflRZ8lm9lVevJrV El6kwrPipC9nFPgWrcBqmSpbzpj+ABfkqZnXxwZAa6hHFfD1Vl8X7svhfAEyZIB6Up LuVYz8jppKoYpQgCqSC0LzT1gfTZUorAFwGqN9Q4RHsgq/nTYtG20d8/bzf5lxMaN9 +LqQzD5P+5AsQ== From: Sean Nyekjaer To: Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Boris Brezillon Cc: Sean Nyekjaer , stable@vger.kernel.org, Boris Brezillon , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] mtd: rawnand: protect access to rawnand devices while in suspend Date: Mon, 31 Jan 2022 22:51:38 +0100 Message-Id: <20220131215138.2013649-1-sean@geanix.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org Prevent rawnend access while in a suspended state. Commit 013e6292aaf5 ("mtd: rawnand: Simplify the locking") allows the rawnand layer to return errors rather than waiting in a blocking wait. Tested on a iMX6ULL. Fixes: 013e6292aaf5 ("mtd: rawnand: Simplify the locking") Signed-off-by: Sean Nyekjaer Reviewed-by: Boris Brezillon --- Follow-up on discussion in: https://lkml.org/lkml/2021/10/4/41 https://lkml.org/lkml/2021/10/11/435 https://lkml.org/lkml/2021/10/20/184 https://lkml.org/lkml/2021/10/25/288 https://lkml.org/lkml/2021/10/26/55 https://lkml.org/lkml/2021/11/2/352 Changes since v1: - fixed uninitialized return drivers/mtd/nand/raw/nand_base.c | 44 +++++++++++++++----------------- include/linux/mtd/rawnand.h | 1 + 2 files changed, 21 insertions(+), 24 deletions(-) diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c index e7b2ba016d8c..8daaba96edb2 100644 --- a/drivers/mtd/nand/raw/nand_base.c +++ b/drivers/mtd/nand/raw/nand_base.c @@ -338,16 +338,19 @@ static int nand_isbad_bbm(struct nand_chip *chip, loff_t ofs) * * Return: -EBUSY if the chip has been suspended, 0 otherwise */ -static int nand_get_device(struct nand_chip *chip) +static void nand_get_device(struct nand_chip *chip) { - mutex_lock(&chip->lock); - if (chip->suspended) { + /* Wait until the device is resumed. */ + while (1) { + mutex_lock(&chip->lock); + if (!chip->suspended) { + mutex_lock(&chip->controller->lock); + return; + } mutex_unlock(&chip->lock); - return -EBUSY; - } - mutex_lock(&chip->controller->lock); - return 0; + wait_event(chip->resume_wq, !chip->suspended); + } } /** @@ -576,9 +579,7 @@ static int nand_block_markbad_lowlevel(struct nand_chip *chip, loff_t ofs) nand_erase_nand(chip, &einfo, 0); /* Write bad block marker to OOB */ - ret = nand_get_device(chip); - if (ret) - return ret; + nand_get_device(chip); ret = nand_markbad_bbm(chip, ofs); nand_release_device(chip); @@ -3826,9 +3827,7 @@ static int nand_read_oob(struct mtd_info *mtd, loff_t from, ops->mode != MTD_OPS_RAW) return -ENOTSUPP; - ret = nand_get_device(chip); - if (ret) - return ret; + nand_get_device(chip); if (!ops->datbuf) ret = nand_do_read_oob(chip, from, ops); @@ -4415,13 +4414,11 @@ static int nand_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops) { struct nand_chip *chip = mtd_to_nand(mtd); - int ret; + int ret = 0; ops->retlen = 0; - ret = nand_get_device(chip); - if (ret) - return ret; + nand_get_device(chip); switch (ops->mode) { case MTD_OPS_PLACE_OOB: @@ -4481,9 +4478,7 @@ int nand_erase_nand(struct nand_chip *chip, struct erase_info *instr, return -EIO; /* Grab the lock and see if the device is available */ - ret = nand_get_device(chip); - if (ret) - return ret; + nand_get_device(chip); /* Shift to get first page */ page = (int)(instr->addr >> chip->page_shift); @@ -4570,7 +4565,7 @@ static void nand_sync(struct mtd_info *mtd) pr_debug("%s: called\n", __func__); /* Grab the lock and see if the device is available */ - WARN_ON(nand_get_device(chip)); + nand_get_device(chip); /* Release it and go back */ nand_release_device(chip); } @@ -4587,9 +4582,7 @@ static int nand_block_isbad(struct mtd_info *mtd, loff_t offs) int ret; /* Select the NAND device */ - ret = nand_get_device(chip); - if (ret) - return ret; + nand_get_device(chip); nand_select_target(chip, chipnr); @@ -4660,6 +4653,8 @@ static void nand_resume(struct mtd_info *mtd) __func__); } mutex_unlock(&chip->lock); + + wake_up_all(&chip->resume_wq); } /** @@ -5437,6 +5432,7 @@ static int nand_scan_ident(struct nand_chip *chip, unsigned int maxchips, chip->cur_cs = -1; mutex_init(&chip->lock); + init_waitqueue_head(&chip->resume_wq); /* Enforce the right timings for reset/detection */ chip->current_interface_config = nand_get_reset_interface_config(); diff --git a/include/linux/mtd/rawnand.h b/include/linux/mtd/rawnand.h index 5b88cd51fadb..99d50a15a263 100644 --- a/include/linux/mtd/rawnand.h +++ b/include/linux/mtd/rawnand.h @@ -1294,6 +1294,7 @@ struct nand_chip { /* Internals */ struct mutex lock; unsigned int suspended : 1; + wait_queue_head_t resume_wq; int cur_cs; int read_retries; struct nand_secure_region *secure_regions;