Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752453AbdHLVfM (ORCPT ); Sat, 12 Aug 2017 17:35:12 -0400 Received: from mail-pf0-f196.google.com ([209.85.192.196]:37869 "EHLO mail-pf0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752419AbdHLVfJ (ORCPT ); Sat, 12 Aug 2017 17:35:09 -0400 Date: Sat, 12 Aug 2017 14:35:04 -0700 From: Brian Norris To: Andrea Adami Cc: linux-mtd@lists.infradead.org, David Woodhouse , Boris Brezillon , Marek Vasut , Richard Weinberger , Cyrille Pitchen , Wolfram Sang , Lee Jones , Daniel Mack , Haojian Zhuang , Dmitry Eremin-Solenikov , Robert Jarzmik , Linus Walleij , Russell King , linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v4 1/9] mtd: sharpslpart: add sharpslpart MTD partition parser Message-ID: <20170812213504.GA90795@google.com> References: <1498681836-3765-1-git-send-email-andrea.adami@gmail.com> <1498681836-3765-2-git-send-email-andrea.adami@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1498681836-3765-2-git-send-email-andrea.adami@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 17214 Lines: 556 Hi Andrea, I'm sorry this had to wait so long, but then...you didn't actually address several of my comments from the last time :( This does look better, but still quite a few smaller notes. Hopefully next one will be merge-able... On Wed, Jun 28, 2017 at 10:30:28PM +0200, Andrea Adami wrote: > The Sharp SL Series (Zaurus) PXA handhelds have 16/64/128M of NAND flash > and share the same layout of the first 7M partition, managed by Sharp FTL. > > The purpose of this self-contained patch is to add a common parser and > remove the hardcoded sizes in the board files (these devices are not yet > converted to devicetree). > Users will have benefits because the mtdparts= tag will not be necessary > anymore and they will be free to repartition the little sized flash. > > The obsolete bootloader can not pass the partitioning info to modern > kernels anymore so it has to be read from flash at known logical addresses. > (see http://www.h5.dion.ne.jp/~rimemoon/zaurus/memo_006.htm ) > > In kernel, under arch/arm/mach-pxa we have already 8 machines: > MACH_POODLE, MACH_CORGI, MACH_SHEPERD, MACH_HUSKY, MACH_AKITA, MACH_SPITZ, > MACH_BORZOI, MACH_TOSA. > Lost after the 2.4 vendor kernel are MACH_BOXER and MACH_TERRIER. > > Almost every model has different factory partitioning: add to this the > units can be repartitioned by users with userspace tools (nandlogical) > and installers for popular (back then) linux distributions. > > The Parameter Area in the first (boot) partition extends from 0x00040000 to > 0x0007bfff (176k) and contains two copies of the partition table: > ... > 0x00060000: Partition Info1 16k > 0x00064000: Partition Info2 16k > 0x00668000: Model 16k > ... > > The first 7M partition is managed by the Sharp FTL reserving 5% + 1 blocks > for wear-leveling: some blocks are remapped and one layer of translation > (logical to physical) is necessary. > > There isn't much documentation about this FTL in the 2.4 sources, just the > MTD methods for reading and writing using logical addresses and the block > management (wear-leveling, use counter). > For the purpose of the MTD parser only the read part of the code was taken. > > The NAND drivers that can use this parser are sharpsl.c and tmio_nand.c. > > Signed-off-by: Andrea Adami > --- > drivers/mtd/Kconfig | 8 + > drivers/mtd/Makefile | 1 + > drivers/mtd/sharpslpart.c | 391 ++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 400 insertions(+) > create mode 100644 drivers/mtd/sharpslpart.c > > diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig > index e83a279..b196a69 100644 > --- a/drivers/mtd/Kconfig > +++ b/drivers/mtd/Kconfig > @@ -155,6 +155,14 @@ config MTD_BCM47XX_PARTS > This provides partitions parser for devices based on BCM47xx > boards. > > +config MTD_SHARPSL_PARTS > + tristate "Sharp SL Series NAND flash partition parser" > + depends on MTD_NAND_SHARPSL || MTD_NAND_TMIO || COMPILE_TEST > + help > + This provides the read-only FTL logic necessary to read the partition > + table from the NAND flash of Sharp SL Series (Zaurus) and the MTD > + partition parser using this code. > + This has conflicts now; probably should go in drivers/mtd/parsers/Kconfig now. We should also probably move the other parsers there, but that's not your problem. > comment "User Modules And Translation Layers" > > # > diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile > index 99bb9a1..e5ef07f 100644 > --- a/drivers/mtd/Makefile > +++ b/drivers/mtd/Makefile > @@ -13,6 +13,7 @@ obj-$(CONFIG_MTD_AFS_PARTS) += afs.o > obj-$(CONFIG_MTD_AR7_PARTS) += ar7part.o > obj-$(CONFIG_MTD_BCM63XX_PARTS) += bcm63xxpart.o > obj-$(CONFIG_MTD_BCM47XX_PARTS) += bcm47xxpart.o > +obj-$(CONFIG_MTD_SHARPSL_PARTS) += sharpslpart.o Also has conflicts now. Might as well move to drivers/mtd/parsers/? > > # 'Users' - code which presents functionality to userspace. > obj-$(CONFIG_MTD_BLKDEVS) += mtd_blkdevs.o > diff --git a/drivers/mtd/sharpslpart.c b/drivers/mtd/sharpslpart.c > new file mode 100644 > index 0000000..02b721b > --- /dev/null > +++ b/drivers/mtd/sharpslpart.c > @@ -0,0 +1,391 @@ > +/* > + * sharpslpart.c - MTD partition parser for NAND flash using the SHARP FTL > + * for logical addressing, as used on the PXA models of the SHARP SL Series. > + * > + * Copyright (C) 2017 Andrea Adami > + * > + * Based on 2.4 sources: > + * drivers/mtd/nand/sharp_sl_logical.c > + * linux/include/asm-arm/sharp_nand_logical.h > + * > + * Copyright (C) 2002 SHARP > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > + > +/* oob structure */ > +#define NAND_NOOB_LOGADDR_00 8 > +#define NAND_NOOB_LOGADDR_01 9 > +#define NAND_NOOB_LOGADDR_10 10 > +#define NAND_NOOB_LOGADDR_11 11 > +#define NAND_NOOB_LOGADDR_20 12 > +#define NAND_NOOB_LOGADDR_21 13 > + > +#define BLOCK_IS_RESERVED 0xffff > +#define BLOCK_UNMASK 0x07fe > +#define BLOCK_UNMASK_COMPLEMENT 1 > + > +/* factory defaults */ > +#define SHARPSL_NAND_PARTS 3 > +#define SHARPSL_FTL_PARTITION_SIZE (7 * 1024 * 1024) > +#define PARAM_BLOCK_PARTITIONINFO1 0x00060000 > +#define PARAM_BLOCK_PARTITIONINFO2 0x00064000 > + > +#define buf_start(x) le32_to_cpu(buf1[x].start) > +#define buf_end(x) le32_to_cpu(buf1[x].end) > +#define buf_magic(x) be32_to_cpu(buf1[x].magic) Sorry, these aren't good macros; they implicitly rely on a 'buf1' variable, without using it as an argument to the macro. That hurts readability. If you want this macro, give it 2 args. > + > +#define BOOT_MAGIC 0x424f4f54 /* BOOT */ > +#define FSRO_MAGIC 0x4653524f /* FSRO */ > +#define FSRW_MAGIC 0x46535257 /* FSRW */ > + > +/* Logical Table */ > +struct mtd_logical { > + u32 size; /* size of the handled partition */ > + int index; /* mtd->index */ > + u_int phymax; /* physical blocks */ > + u_int logmax; /* logical blocks */ > + u_int *log2phy; /* the logical-to-physical table */ > +}; > + > +struct mtd_logical *sharpsl_mtd_logical; I asked you not to avoid making this variable static...and I suppose technically you did this. But global is even worse! And you really don't need to do this; just make sharpsl_nand_init_logical() return struct mtd_logical, and then you don't need any global/static reference at all. > + > +/* > + * SHARP SL FTL ancillary functions > + * > + */ > + > +static int sharpsl_nand_read_oob(struct mtd_info *mtd, loff_t offs, size_t len, > + uint8_t *buf) > +{ > + loff_t mask = mtd->writesize - 1; > + struct mtd_oob_ops ops; > + int ret; > + > + ops.mode = MTD_OPS_PLACE_OOB; > + ops.ooboffs = offs & mask; > + ops.ooblen = len; > + ops.oobbuf = buf; > + ops.datbuf = NULL; > + > + ret = mtd_read_oob(mtd, offs & ~mask, &ops); > + if (ret != 0 || len != ops.oobretlen) > + return -1; > + > + return 0; > +} > + > +/* > + * The logical block number assigned to a physical block is stored in the OOB > + * of the first page, in 3 16-bit copies with the following layout: > + * > + * 01234567 89abcdef > + * -------- -------- > + * ECC BB xyxyxy > + * > + * When reading we check that the first two copies agree. > + * In case of error, matching is tried using the following pairs. > + * Reserved values 0xffff mean the block is kept for wear leveling. > + * > + * 01234567 89abcdef > + * -------- -------- > + * ECC BB xyxy oob[8]==oob[10] && oob[9]==oob[11] -> byte0=8 byte1=9 > + * ECC BB xyxy oob[10]==oob[12] && oob[11]==oob[13] -> byte0=10 byte1=11 > + * ECC BB xy xy oob[12]==oob[8] && oob[13]==oob[9] -> byte0=12 byte1=13 > + * > + */ Thanks for this. Much nicer. > + > +static u_int sharpsl_nand_get_logical_num(u_char *oob) > +{ > + u16 us; > + int good0, good1; > + > + if (oob[NAND_NOOB_LOGADDR_00] == oob[NAND_NOOB_LOGADDR_10] && > + oob[NAND_NOOB_LOGADDR_01] == oob[NAND_NOOB_LOGADDR_11]) { > + good0 = NAND_NOOB_LOGADDR_00; > + good1 = NAND_NOOB_LOGADDR_01; > + } else if (oob[NAND_NOOB_LOGADDR_10] == oob[NAND_NOOB_LOGADDR_20] && > + oob[NAND_NOOB_LOGADDR_11] == oob[NAND_NOOB_LOGADDR_21]) { > + good0 = NAND_NOOB_LOGADDR_10; > + good1 = NAND_NOOB_LOGADDR_11; > + } else if (oob[NAND_NOOB_LOGADDR_20] == oob[NAND_NOOB_LOGADDR_00] && > + oob[NAND_NOOB_LOGADDR_21] == oob[NAND_NOOB_LOGADDR_01]) { > + good0 = NAND_NOOB_LOGADDR_20; > + good1 = NAND_NOOB_LOGADDR_21; > + } else { > + /* wrong oob fingerprint, maybe here by mistake? */ > + return UINT_MAX; > + } > + > + us = oob[good0] | oob[good1] << 8; > + > + /* parity check */ > + if (hweight16(us) & BLOCK_UNMASK_COMPLEMENT) > + return (UINT_MAX - 1); > + > + /* reserved */ > + if (us == BLOCK_IS_RESERVED) > + return BLOCK_IS_RESERVED; > + else > + return (us & BLOCK_UNMASK) >> 1; > +} > + > +int sharpsl_nand_init_logical(struct mtd_info *mtd, u32 partition_size) static? > +{ > + struct mtd_logical *logical; > + u_int block_num, log_num; > + loff_t block_adr; > + u_char *oob; > + int i; > + > + logical = kzalloc(sizeof(*logical), GFP_KERNEL); > + if (!logical) > + return -ENOMEM; > + > + oob = kzalloc(mtd->oobsize, GFP_KERNEL); > + if (!oob) { > + kfree(logical); > + return -ENOMEM; > + } > + > + /* initialize management structure */ > + logical->size = partition_size; > + logical->index = mtd->index; > + logical->phymax = (partition_size / mtd->erasesize); > + > + /* FTL reserves 5% of the blocks + 1 spare */ > + logical->logmax = ((logical->phymax * 95) / 100) - 1; > + > + logical->log2phy = NULL; What's this for? You're re-assigning it immediately following. > + logical->log2phy = kmalloc_array(logical->logmax, sizeof(u_int), > + GFP_KERNEL); > + if (!logical->log2phy) { > + kfree(logical); > + kfree(oob); > + return -ENOMEM; > + } > + > + /* initialize logical->log2phy */ > + for (i = 0; i < logical->logmax; i++) > + logical->log2phy[i] = UINT_MAX; > + > + /* create physical-logical table */ > + for (block_num = 0; block_num < logical->phymax; block_num++) { > + block_adr = block_num * mtd->erasesize; > + > + if (mtd_block_isbad(mtd, block_adr)) > + continue; > + > + if (sharpsl_nand_read_oob(mtd, block_adr, mtd->oobsize, oob)) > + continue; > + > + /* get logical block */ > + log_num = sharpsl_nand_get_logical_num(oob); > + > + /* FTL is not used? Exit here if the oob fingerprint is wrong */ > + if (log_num == UINT_MAX) { > + pr_info("sharpslpart: Sharp SL FTL not found. Quit parser.\n"); > + kfree(logical->log2phy); > + kfree(logical); > + kfree(oob); > + return -EINVAL; > + } > + > + /* skip out of range and not unique values */ > + if (log_num < logical->logmax) { > + if (logical->log2phy[log_num] == UINT_MAX) > + logical->log2phy[log_num] = block_num; > + } > + } > + kfree(oob); > + sharpsl_mtd_logical = logical; > + > + pr_info("Sharp SL FTL: %d blocks used (%d logical, %d reserved)\n", > + logical->phymax, logical->logmax, > + logical->phymax - logical->logmax); > + > + return 0; > +} > + > +void sharpsl_nand_cleanup_logical(struct mtd_logical *sharpsl_mtd_logical) static? And why don't you just name the arg 'logical' and... > +{ > + struct mtd_logical *logical = sharpsl_mtd_logical; ...drop this? > + > + sharpsl_mtd_logical = NULL; If you kill the global, you don't need this. > + > + kfree(logical->log2phy); > + logical->log2phy = NULL; Not necessary. > + kfree(logical); > + logical = NULL; Not necessary. > +} > + > +int sharpsl_nand_read_laddr(struct mtd_info *mtd, static? > + loff_t from, > + size_t len, > + u_char *buf) > +{ > + struct mtd_logical *logical; Make 'logical' a parameter, so you don't need the global. > + u_int log_num, log_new; > + u_int block_num; > + loff_t block_adr; > + loff_t block_ofs; > + size_t retlen; > + int err; > + > + logical = sharpsl_mtd_logical; > + log_num = (u32)from / mtd->erasesize; > + log_new = ((u32)from + len - 1) / mtd->erasesize; > + > + if (len <= 0 || log_num >= logical->logmax || log_new > log_num) > + return -EINVAL; > + > + block_num = logical->log2phy[log_num]; > + block_adr = block_num * mtd->erasesize; > + block_ofs = (u32)from % mtd->erasesize; > + > + err = mtd_read(mtd, block_adr + block_ofs, len, &retlen, buf); > + /* Ignore corrected ECC errors */ > + if (mtd_is_bitflip(err)) > + err = 0; > + if (!err && retlen != len) > + err = -EIO; > + if (err) > + pr_err("sharpslpart: error, read failed at %#llx\n", > + block_adr + block_ofs); > + > + return err; > +} > + > +/* > + * MTD Partition Parser > + * > + */ > + > +struct sharpsl_nand_partitioninfo { > + u32 start; > + u32 end; Should the above 2 be '__le32'? > + u32 magic; It's a little odd that the same on-flash structure would have both BE and LE elements, but I guess judging by usage...this should be '__be32'. > + u32 reserved; > +}; > + > +/* > + * Sample values read from SL-C860 > + * > + * # cat /proc/mtd > + * dev: size erasesize name > + * mtd0: 006d0000 00020000 "Filesystem" > + * mtd1: 00700000 00004000 "smf" > + * mtd2: 03500000 00004000 "root" > + * mtd3: 04400000 00004000 "home" > + * > + * PARTITIONINFO1 > + * 0x00060000: 00 00 00 00 00 00 70 00 42 4f 4f 54 00 00 00 00 ......p.BOOT.... > + * 0x00060010: 00 00 70 00 00 00 c0 03 46 53 52 4f 00 00 00 00 ..p.....FSRO.... > + * 0x00060020: 00 00 c0 03 00 00 00 04 46 53 52 57 00 00 00 00 ........FSRW.... > + * 0x00060030: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................ > + * > + */ > + > +static int sharpsl_parse_mtd_partitions(struct mtd_info *master, > + const struct mtd_partition **pparts, > + struct mtd_part_parser_data *data) > +{ > + struct sharpsl_nand_partitioninfo buf1[SHARPSL_NAND_PARTS]; > + struct sharpsl_nand_partitioninfo buf2[SHARPSL_NAND_PARTS]; > + struct mtd_partition *sharpsl_nand_parts; > + int err; > + > + /* init logical mgmt (FTL) */ > + if (sharpsl_nand_init_logical(master, SHARPSL_FTL_PARTITION_SIZE)) > + return -EINVAL; Please propagate the error... > + > + /* read the two partition tables */ > + err = sharpsl_nand_read_laddr(master, > + PARAM_BLOCK_PARTITIONINFO1, > + sizeof(buf1), (u_char *)&buf1); > + if (!err) { > + sharpsl_nand_read_laddr(master, > + PARAM_BLOCK_PARTITIONINFO2, > + sizeof(buf2), (u_char *)&buf2); You don't really need this block under the 'if'. You can just invert this to 'if (err)', since the second block will return early. Brian > + } else { > + sharpsl_nand_cleanup_logical(sharpsl_mtd_logical); > + return err; > + } > + > + /* cleanup logical mgmt (FTL) */ > + sharpsl_nand_cleanup_logical(sharpsl_mtd_logical); > + > + /* compare the two buffers */ > + if (memcmp(&buf1, &buf2, sizeof(buf1))) { > + pr_err("sharpslpart: PARTITIONINFO 1,2 differ. Quit parser.\n"); > + return -EINVAL; > + } > + > + /* check for magics (just in the first) */ > + if (buf_magic(0) != BOOT_MAGIC || > + buf_magic(1) != FSRO_MAGIC || > + buf_magic(2) != FSRW_MAGIC) { > + pr_err("sharpslpart: magic values mismatch. Quit parser.\n"); > + return -EINVAL; > + } > + > + /* fixup for hardcoded value 64 MiB (for older models) */ > + buf1[2].end = cpu_to_le32(master->size); > + > + /* extra sanity check */ > + if (buf_end(0) <= buf_start(0) || > + buf_start(1) < buf_end(0) || > + buf_end(1) <= buf_start(1) || > + buf_start(2) < buf_end(1) || > + buf_end(2) <= buf_start(2)) { > + pr_err("sharpslpart: partition sizes mismatch. Quit parser.\n"); > + return -EINVAL; > + } > + > + sharpsl_nand_parts = kzalloc(sizeof(*sharpsl_nand_parts) * > + SHARPSL_NAND_PARTS, GFP_KERNEL); > + if (!sharpsl_nand_parts) > + return -ENOMEM; > + > + /* original names */ > + sharpsl_nand_parts[0].name = "smf"; > + sharpsl_nand_parts[0].offset = buf_start(0); > + sharpsl_nand_parts[0].size = buf_end(0) - buf_start(0); > + > + sharpsl_nand_parts[1].name = "root"; > + sharpsl_nand_parts[1].offset = buf_start(1); > + sharpsl_nand_parts[1].size = buf_end(1) - buf_start(1); > + > + sharpsl_nand_parts[2].name = "home"; > + sharpsl_nand_parts[2].offset = buf_start(2); > + sharpsl_nand_parts[2].size = buf_end(2) - buf_start(2); > + > + *pparts = sharpsl_nand_parts; > + return SHARPSL_NAND_PARTS; > +} > + > +static struct mtd_part_parser sharpsl_mtd_parser = { > + .parse_fn = sharpsl_parse_mtd_partitions, > + .name = "sharpslpart", > +}; > +module_mtd_part_parser(sharpsl_mtd_parser); > + > +MODULE_LICENSE("GPL"); > +MODULE_AUTHOR("Andrea Adami "); > +MODULE_DESCRIPTION("MTD partitioning for NAND flash on Sharp SL Series"); > -- > 2.7.4 >