From patchwork Mon Aug 2 19:40:48 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefani Seibold X-Patchwork-Id: 60565 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from bombadil.infradead.org (bombadil.infradead.org [18.85.46.34]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 5CFC7B70A6 for ; Tue, 3 Aug 2010 05:43:08 +1000 (EST) Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.72 #1 (Red Hat Linux)) id 1Og0sp-0002XY-Pj; Mon, 02 Aug 2010 19:41:11 +0000 Received: from www84.your-server.de ([213.133.104.84]) by bombadil.infradead.org with esmtps (Exim 4.72 #1 (Red Hat Linux)) id 1Og0sn-0002Sq-7A for linux-mtd@lists.infradead.org; Mon, 02 Aug 2010 19:41:10 +0000 Received: from [88.64.6.23] (helo=localhost.localdomain) by www84.your-server.de with esmtpa (Exim 4.69) (envelope-from ) id 1Og0sb-0004WD-BU; Mon, 02 Aug 2010 21:40:57 +0200 From: stefani@seibold.net To: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, Arnd Bergmann , Vasiliy Kulikov , Artem Bityutskiy , David Woodhouse , Nicolas Pitre , Hans-Christian Egtvedt , Jiri Slaby , Tejun Heo , linux-mtd@lists.infradead.org Subject: [PATCH] Change struct flchip_shared spinlock locking into mutex Date: Mon, 2 Aug 2010 21:40:48 +0200 Message-Id: <1280778048-6208-1-git-send-email-stefani@seibold.net> X-Mailer: git-send-email 1.7.2 X-Authenticated-Sender: stefani@seibold.net X-Virus-Scanned: Clear (ClamAV 0.96.1/11484/Mon Aug 2 19:56:16 2010) X-CRM114-Version: 20090807-BlameThorstenAndJenny ( TRE 0.7.6 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20100802_154109_520248_054A8847 X-CRM114-Status: GOOD ( 19.02 ) X-Spam-Score: 0.0 (/) X-Spam-Report: SpamAssassin version 3.3.1 on bombadil.infradead.org summary: Content analysis details: (0.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- Cc: stefani@seibold.net X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linux-mtd-bounces@lists.infradead.org Errors-To: linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org From: Stefani Seibold This patch prevent to schedule while atomic by changing the flchip_shared spinlock into a mutex. This should be save since no atomic path will use this lock. This patch is based on linux kernel 2.6.35. Please apply. It was requested by Arnd Bergmann and Vasiliy Kulikov. - Stefani shared-> Signed-off-by: Stefani Seibold Acked-by: Arnd Bergmann --- drivers/mtd/chips/cfi_cmdset_0001.c | 20 ++++++++++---------- include/linux/mtd/flashchip.h | 2 +- 2 files changed, 11 insertions(+), 11 deletions(-) diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c index 62f3ea9..3364061 100644 --- a/drivers/mtd/chips/cfi_cmdset_0001.c +++ b/drivers/mtd/chips/cfi_cmdset_0001.c @@ -717,7 +717,7 @@ static int cfi_intelext_partition_fixup(struct mtd_info *mtd, chip = &newcfi->chips[0]; for (i = 0; i < cfi->numchips; i++) { shared[i].writing = shared[i].erasing = NULL; - spin_lock_init(&shared[i].lock); + mutex_init(&shared[i].lock); for (j = 0; j < numparts; j++) { *chip = cfi->chips[i]; chip->start += j << partshift; @@ -886,7 +886,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr */ struct flchip_shared *shared = chip->priv; struct flchip *contender; - spin_lock(&shared->lock); + mutex_lock(&shared->lock); contender = shared->writing; if (contender && contender != chip) { /* @@ -899,7 +899,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr * get_chip returns success we're clear to go ahead. */ ret = mutex_trylock(&contender->mutex); - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); if (!ret) goto retry; mutex_unlock(&chip->mutex); @@ -914,7 +914,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr mutex_unlock(&contender->mutex); return ret; } - spin_lock(&shared->lock); + mutex_lock(&shared->lock); /* We should not own chip if it is already * in FL_SYNCING state. Put contender and retry. */ @@ -930,7 +930,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr * on this chip. Sleep. */ if (mode == FL_ERASING && shared->erasing && shared->erasing->oldstate == FL_ERASING) { - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); set_current_state(TASK_UNINTERRUPTIBLE); add_wait_queue(&chip->wq, &wait); mutex_unlock(&chip->mutex); @@ -944,7 +944,7 @@ static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr shared->writing = chip; if (mode == FL_ERASING) shared->erasing = chip; - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); } ret = chip_ready(map, chip, adr, mode); if (ret == -EAGAIN) @@ -959,7 +959,7 @@ static void put_chip(struct map_info *map, struct flchip *chip, unsigned long ad if (chip->priv) { struct flchip_shared *shared = chip->priv; - spin_lock(&shared->lock); + mutex_lock(&shared->lock); if (shared->writing == chip && chip->oldstate == FL_READY) { /* We own the ability to write, but we're done */ shared->writing = shared->erasing; @@ -967,7 +967,7 @@ static void put_chip(struct map_info *map, struct flchip *chip, unsigned long ad /* give back ownership to who we loaned it from */ struct flchip *loaner = shared->writing; mutex_lock(&loaner->mutex); - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); mutex_unlock(&chip->mutex); put_chip(map, loaner, loaner->start); mutex_lock(&chip->mutex); @@ -985,11 +985,11 @@ static void put_chip(struct map_info *map, struct flchip *chip, unsigned long ad * Don't let the switch below mess things up since * we don't have ownership to resume anything. */ - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); wake_up(&chip->wq); return; } - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); } switch(chip->oldstate) { diff --git a/include/linux/mtd/flashchip.h b/include/linux/mtd/flashchip.h index f43e9b4..23cc10f 100644 --- a/include/linux/mtd/flashchip.h +++ b/include/linux/mtd/flashchip.h @@ -92,7 +92,7 @@ struct flchip { /* This is used to handle contention on write/erase operations between partitions of the same physical chip. */ struct flchip_shared { - spinlock_t lock; + struct mutex lock; struct flchip *writing; struct flchip *erasing; };