From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965124AbdEWAo0 (ORCPT ); Mon, 22 May 2017 20:44:26 -0400 Received: from gate2.alliedtelesis.co.nz ([202.36.163.20]:45391 "EHLO gate2.alliedtelesis.co.nz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935471AbdEWAnX (ORCPT ); Mon, 22 May 2017 20:43:23 -0400 From: Chris Packham To: linux-mtd@lists.infradead.org, andrew@lunn.ch, computersforpeace@gmail.com, dwmw2@infradead.org, boris.brezillon@free-electrons.com, linux-kernel@vger.kernel.org Cc: Chris Packham , Marek Vasut , Richard Weinberger , Cyrille Pitchen Subject: [PATCH v3 3/5] mtd: handle partitioning on devices with 0 erasesize Date: Tue, 23 May 2017 12:43:15 +1200 Message-Id: <20170523004317.16908-4-chris.packham@alliedtelesis.co.nz> X-Mailer: git-send-email 2.11.0.24.ge6920cf In-Reply-To: <20170523004317.16908-1-chris.packham@alliedtelesis.co.nz> References: <20170523004317.16908-1-chris.packham@alliedtelesis.co.nz> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org erasesize is meaningful for flash devices but for SRAM there is no concept of an erase block so erasesize is set to 0. When partitioning these devices instead of ensuring partitions fall on erasesize boundaries we ensure they fall on writesize boundaries. Helped-by: Boris Brezillon Signed-off-by: Chris Packham --- Changes in v3: - new drivers/mtd/mtdpart.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c index ea5e5307f667..5cef1247806c 100644 --- a/drivers/mtd/mtdpart.c +++ b/drivers/mtd/mtdpart.c @@ -393,8 +393,11 @@ static struct mtd_part *allocate_partition(struct mtd_info *master, const struct mtd_partition *part, int partno, uint64_t cur_offset) { + int wr_alignment = master->erasesize ? : master->writesize; struct mtd_part *slave; + u32 remainder; char *name; + u64 tmp; /* allocate the partition structure */ slave = kzalloc(sizeof(*slave), GFP_KERNEL); @@ -499,10 +502,11 @@ static struct mtd_part *allocate_partition(struct mtd_info *master, if (slave->offset == MTDPART_OFS_APPEND) slave->offset = cur_offset; if (slave->offset == MTDPART_OFS_NXTBLK) { + tmp = cur_offset; slave->offset = cur_offset; - if (mtd_mod_by_eb(cur_offset, master) != 0) { - /* Round up to next erasesize */ - slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize; + remainder = do_div(tmp, wr_alignment); + if (remainder) { + slave->offset += wr_alignment - remainder; printk(KERN_NOTICE "Moving partition %d: " "0x%012llx -> 0x%012llx\n", partno, (unsigned long long)cur_offset, (unsigned long long)slave->offset); @@ -567,19 +571,22 @@ static struct mtd_part *allocate_partition(struct mtd_info *master, slave->mtd.erasesize = master->erasesize; } - if ((slave->mtd.flags & MTD_WRITEABLE) && - mtd_mod_by_eb(slave->offset, &slave->mtd)) { + tmp = slave->offset; + remainder = do_div(tmp, wr_alignment); + if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) { /* Doesn't start on a boundary of major erase size */ /* FIXME: Let it be writable if it is on a boundary of * _minor_ erase size though */ slave->mtd.flags &= ~MTD_WRITEABLE; - printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n", + printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase/write block boundary -- force read-only\n", part->name); } - if ((slave->mtd.flags & MTD_WRITEABLE) && - mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) { + + tmp = slave->mtd.size; + remainder = do_div(tmp, wr_alignment); + if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) { slave->mtd.flags &= ~MTD_WRITEABLE; - printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n", + printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase/write block -- force read-only\n", part->name); } -- 2.11.0.24.ge6920cf