Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752634AbdFTIw7 (ORCPT ); Tue, 20 Jun 2017 04:52:59 -0400 Received: from mail-wm0-f67.google.com ([74.125.82.67]:34814 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752542AbdFTIww (ORCPT ); Tue, 20 Jun 2017 04:52:52 -0400 MIME-Version: 1.0 In-Reply-To: <20170609013048.GK102137@google.com> References: <1496270458-6479-1-git-send-email-andrea.adami@gmail.com> <1496270458-6479-2-git-send-email-andrea.adami@gmail.com> <20170609013048.GK102137@google.com> From: Andrea Adami Date: Tue, 20 Jun 2017 10:52:44 +0200 Message-ID: Subject: Re: [PATCH v3 1/9] mtd: sharpslpart: add sharpslpart MTD partition parser To: Brian Norris 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 Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 23736 Lines: 687 Brian, thanks for the review and for the unvaluable advices. I have almost fixed the problems you spotted and I am almost ready to send the new v4 of the patchset. Some doubts are still present: I'll comment under your remarks: On Fri, Jun 9, 2017 at 3:30 AM, Brian Norris wrote: > Hi, > > On Thu, Jun 01, 2017 at 12:40:50AM +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 | 2 + >> drivers/mtd/sharpsl_ftl.c | 216 ++++++++++++++++++++++++++++++++++++++++++++++ >> drivers/mtd/sharpsl_ftl.h | 34 ++++++++ >> drivers/mtd/sharpslpart.c | 132 ++++++++++++++++++++++++++++ >> 5 files changed, 392 insertions(+) >> create mode 100644 drivers/mtd/sharpsl_ftl.c >> create mode 100644 drivers/mtd/sharpsl_ftl.h >> create mode 100644 drivers/mtd/sharpslpart.c >> >> diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig >> index e83a279..5c96127 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 > > Please include '|| 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. >> + >> comment "User Modules And Translation Layers" >> >> # >> diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile >> index 99bb9a1..89f707b 100644 >> --- a/drivers/mtd/Makefile >> +++ b/drivers/mtd/Makefile >> @@ -13,6 +13,8 @@ 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-$(CONFIG_MTD_SHARPSL_PARTS) += sharpsl-part.o >> +sharpsl-part-objs := sharpsl_ftl.o sharpslpart.o >> >> # 'Users' - code which presents functionality to userspace. >> obj-$(CONFIG_MTD_BLKDEVS) += mtd_blkdevs.o >> diff --git a/drivers/mtd/sharpsl_ftl.c b/drivers/mtd/sharpsl_ftl.c >> new file mode 100644 >> index 0000000..1796d03 >> --- /dev/null >> +++ b/drivers/mtd/sharpsl_ftl.c >> @@ -0,0 +1,216 @@ >> +/* >> + * MTD method for NAND accessing via logical address (SHARP FTL) >> + * >> + * Copyright (C) 2017 Andrea Adami >> + * >> + * Based on 2.4 sources: drivers/mtd/nand/sharp_sl_logical.c >> + * 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 >> +#include "sharpsl_ftl.h" >> + >> +/* 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 >> + >> +/* 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 */ >> +}; >> + >> +static struct mtd_logical *sharpsl_mtd_logical; > > Please do not use a static variable like this. References should be > dynamic. > > Can the pointer just be passed back to the caller, and passed back to > the cleanup function when finished? > I'll fix this. > Related: do you foresee this parsing code being useful for anything > besides partitions? If not, then it seems like we should just merge the > "ftl" and "part" files. Not a requirement, but it might be cleaner. > I think it makes sense to merge back together. It was earlier split to better expose the read-only FTL. >> + >> +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; >> +} >> + >> +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 { >> + return UINT_MAX; >> + } > > These seems like a pretty weird form of error protection. IIUC, there > are just 3 copies of the 2-byte sequence number, and we take the first > pair that matches at least one of the others? Could use a comment above > the if/else block, to explain what the logic is. Or perhaps even some > comments at the top of the file, to roughly describe this FTL. > I am sorry I don't know much about error correction. No info, no comments in the 2.4 sources. My tests did indeed show that only the first condition is matched (good0=8 good1=9) so I'll retry and then I'll simplify the code.. >> + >> + us = oob[good0] | oob[good1] << 8; >> + >> + /* parity check */ >> + if (hweight16(us) & 1) >> + return (UINT_MAX - 1); >> + >> + /* reserved */ >> + if (us == 0xffff) > > Magic number should get a descriptive macro? > done (BLOCK_IS_RESERVED) >> + return 0xffff; > > What does this mean? IIUC, this is essentially going to be an > out-of-bounds value that gets ignored, right? Should this just be > 'return UINT_MAX'? > Done. it is the same with the simplified code we are using. If you look in the 2.4 sources there was a further check to verify the usage [1] [ 1] https://github.com/LinuxPDA/Sharp_FTL_2.4.20/blob/master/linux/drivers/mtd/nand/sharp_sl_logical.c#L453 >> + else >> + return (us & 0x07fe) >> 1; > > 0x07fe could use a macro definition. (And since it seems complementary, > I guess the 1 in 'hweight16(us) & 1' should also be a macro.) > Done BLOCK_UNMASK 0x07fe BLOCK_UNMASK_COMPLEMENT 1 >> +} >> + >> +int sharpsl_nand_init_logical(struct mtd_info *mtd, u32 partition_size) >> +{ >> + struct mtd_logical *logical = NULL; > > You don't need the NULL initialization. Fixed (all these are remnants of the 2.4 conversion...) > >> + u_int block_num, log_num; >> + loff_t block_adr; >> + u_char *oob = NULL; > > Same here. > Done >> + int i, readretry; >> + >> + 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; >> + logical->log2phy = kcalloc(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; > > The 0-initialized kcalloc() is a little superfluous, since you reinit > here. I guess it's a matter of taste. > Well, right, my bad. The original code [2] did kmalloc() + memset so checkpatch suggested to use kcalloc(). But the simplified code we are using does not need it (we ignore 'usage'). I'll change back to kmalloc() and initialize to UINT_MAX. [2] https://github.com/LinuxPDA/Sharp_FTL_2.4.20/blob/master/linux/drivers/mtd/nand/sharp_sl_logical.c#L395 >> + >> + /* 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; >> + >> + readretry = 3; >> +read_retry: >> + if (sharpsl_nand_read_oob(mtd, block_adr, mtd->oobsize, oob)) >> + continue; >> + >> + /* get logical block */ >> + log_num = sharpsl_nand_get_logical_num(oob); >> + >> + /* skip out of range and not unique values */ >> + if ((int)log_num >= 0 && (log_num < logical->logmax)) { > > Why the (int) cast? You should already be eliminating anything larger > than INT_MAX, because they'll be larger than logmax. You should only > need the second comparison. > Fixed both. The cast is another remnant of the (many) checks done in the old sources. My bad I have let some superfluous code during conversion.... >> + if (logical->log2phy[log_num] == UINT_MAX) >> + logical->log2phy[log_num] = block_num; >> + } else { >> + readretry--; >> + if (readretry) >> + goto read_retry; > > What's the idea on the retries? Is this somehow supposed to make NAND > more reliable? That seems unlikely to work... Although notably, OOB is > often not covered by ECC, so maybe this is a really poor attempt at > making up for that? > :) Yes, it seems poor-man's solution but is indeed in the 2.4 sources. Not needed (tested). Removed. >> + } >> + } >> + 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(void) >> +{ >> + struct mtd_logical *logical = sharpsl_mtd_logical; > > Please make this take a pointer arg, instead of relying on a static var. > Sure, as above I'll avoid the static var. >> + >> + sharpsl_mtd_logical = NULL; >> + >> + kfree(logical->log2phy); >> + logical->log2phy = NULL; >> + kfree(logical); >> + logical = NULL; >> +} >> + >> +int sharpsl_nand_read_laddr(struct mtd_info *mtd, >> + loff_t from, >> + size_t len, >> + u_char *buf) >> +{ >> + struct mtd_logical *logical; >> + u_int log_num, log_new; >> + u_int block_num; >> + loff_t block_adr; >> + loff_t block_ofs; >> + size_t retlen; >> + int ret; >> + >> + 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; >> + >> + ret = mtd_read(mtd, block_adr + block_ofs, len, &retlen, buf); >> + if (ret != 0 || len != retlen) > > What about ret == -EUCLEAN? Do you want to handle corrected bitflips? > I have changed the checks here and have taken the code of mtdtest_read() so to ignorer bitflips and pass the error through. >> + return -EINVAL; >> + >> + return 0; >> +} >> diff --git a/drivers/mtd/sharpsl_ftl.h b/drivers/mtd/sharpsl_ftl.h >> new file mode 100644 >> index 0000000..2880cbe >> --- /dev/null >> +++ b/drivers/mtd/sharpsl_ftl.h >> @@ -0,0 +1,34 @@ >> +/* >> + * Header file for NAND accessing via logical address (SHARP FTL) >> + * >> + * Copyright (C) 2017 Andrea Adami >> + * >> + * Based on 2.4 sources: 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. >> + * >> + */ >> + >> +#ifndef __SHARPSL_NAND_LOGICAL_H__ >> +#define __SHARPSL_NAND_LOGICAL_H__ >> + >> +#include >> +#include >> + >> +int sharpsl_nand_init_logical(struct mtd_info *mtd, u32 partition_size); >> + >> +void sharpsl_nand_cleanup_logical(void); >> + >> +int sharpsl_nand_read_laddr(struct mtd_info *mtd, loff_t from, size_t len, >> + u_char *buf); >> + >> +#endif >> diff --git a/drivers/mtd/sharpslpart.c b/drivers/mtd/sharpslpart.c >> new file mode 100644 >> index 0000000..40aebe9 >> --- /dev/null >> +++ b/drivers/mtd/sharpslpart.c >> @@ -0,0 +1,132 @@ >> +/* >> + * MTD partition parser for NAND flash on Sharp SL Series >> + * >> + * Copyright (C) 2017 Andrea Adami >> + * >> + * 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 "sharpsl_ftl.h" >> + >> +/* 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 BOOT_MAGIC be32_to_cpu(0x424f4f54) /* BOOT */ >> +#define FSRO_MAGIC be32_to_cpu(0x4653524f) /* FSRO */ >> +#define FSRW_MAGIC be32_to_cpu(0x46535257) /* FSRW */ >> + >> +/* >> + * 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 ................ >> + * >> + */ >> + >> +struct sharpsl_nand_partitioninfo { >> + u32 start; >> + u32 end; >> + u32 magic; >> + u32 reserved; >> +}; >> + >> +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; >> + >> + /* init logical mgmt (FTL) */ > > Do you have any kind of validation logic, to ensure that this parser > actually matches? What if the flash was erased? Or what if somebody > managed to reformat to some other flash layout? > The bootloader loads and launches the zImage1 found at a specific logical address. If mtd1 were invalid there would be no boot. See, 10yrs ago there was an unofficial u-boot port for experienced users. That was requiring to full-erase the nand, so removing the maintenance and diag code This would be the only case of modified partition layout I can think of. > I suppose for many cases like that, the logical mapping will turn up > with a lot of UINT_MAX entries, and then sharpsl_nand_read_laddr() will > return -EINVAL? It'd be nice if there were some more clear sanity > checks though, if possible. Does this FTL have a header we should be > looking for? I expect -EINVAL in that case. BUT if one would be usingh u-boot then he'd have partitions in u-boot.env or in cmdline. The (infamous) header is copied here: https://github.com/LinuxPDA/Sharp_FTL_2.4.20/blob/master/linux/drivers/mtd/nand/sharp_sl_logical.c Full sources available at http://support.ezaurus.com/developer/source/source_dl.asp > >> + if (sharpsl_nand_init_logical(master, SHARPSL_FTL_PARTITION_SIZE)) >> + return -EINVAL; >> + >> + /* read the two partition tables */ >> + if (sharpsl_nand_read_laddr(master, >> + PARAM_BLOCK_PARTITIONINFO1, >> + sizeof(buf1), (u_char *)&buf1) || >> + sharpsl_nand_read_laddr(master, >> + PARAM_BLOCK_PARTITIONINFO2, >> + sizeof(buf2), (u_char *)&buf2)) >> + return -EINVAL; > > You've failed to cleanup in the error case here: > sharpsl_nand_cleanup_logical() > Argh, fixed. > Also, consider passing through the actual error code? > Yes, done, >> + >> + /* cleanup logical mgmt (FTL) */ >> + sharpsl_nand_cleanup_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 (buf1[0].magic != BOOT_MAGIC || >> + buf1[1].magic != FSRO_MAGIC || >> + buf1[2].magic != FSRW_MAGIC) { >> + pr_err("sharpslpart: magic values 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 = buf1[0].start; >> + sharpsl_nand_parts[0].size = buf1[0].end - buf1[0].start; > > Want to sanity check that 'end > start'? > Done, I have added a sanity check. >> + sharpsl_nand_parts[0].mask_flags = 0; > > Don't need to zero this out, when you've used kzalloc(). Same comments > apply below. > Yes, fixed. (I have copied without much thinking from ar7part.c) >> + >> + sharpsl_nand_parts[1].name = "root"; >> + sharpsl_nand_parts[1].offset = buf1[1].start; >> + sharpsl_nand_parts[1].size = buf1[1].end - buf1[1].start; >> + sharpsl_nand_parts[1].mask_flags = 0; >> + >> + sharpsl_nand_parts[2].name = "home"; >> + sharpsl_nand_parts[2].offset = buf1[2].start; >> + /* discard buf1[2].end, was for older models with 64M flash */ >> + sharpsl_nand_parts[2].size = master->size - buf1[2].start; >> + sharpsl_nand_parts[2].mask_flags = 0; >> + >> + *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"); > > Brian Thanks for your time. Regards Andrea