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path: root/drivers/mtd/mtdchar.c
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2010-08-04mtd: mtdchar: fix mmap for MTD RAM/ROM char devicesAnatolij Gustschin
For no-mmu systems mmap() on RAM/ROM devices already works but for systems with mmu it probably was not tested and doesn't work. This patch allows using mmap() on MTD RAM/ROM devices on systems with MMU. It has been tested on mpc5121e based platform with MR0A16A MRAM device attached over LocalBus. Signed-off-by: Anatolij Gustschin <agust@denx.de> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2010-08-02mtd: add an ioctl to query the lock status of a flash sectorRichard Cochran
This patchs adds a way for user space programs to find out whether a flash sector is locked. An optional driver method in the mtd_info struct provides the information. Signed-off-by: Richard Cochran <richard.cochran@omicron.at> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2010-05-22drivers/mtd: Use memdup_userJulia Lawall
Use memdup_user when user data is immediately copied into the allocated region. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ expression from,to,size,flag; position p; identifier l1,l2; @@ - to = \(kmalloc@p\|kzalloc@p\)(size,flag); + to = memdup_user(from,size); if ( - to==NULL + IS_ERR(to) || ...) { <+... when != goto l1; - -ENOMEM + PTR_ERR(to) ...+> } - if (copy_from_user(to, from, size) != 0) { - <+... when != goto l2; - -EFAULT - ...+> - } // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2010-05-18mtd: mtdchar: Do not corrupt backing device of device node inodeKirill A. Shutemov
We cannot modify file->f_mapping->backing_dev_info, because it will corrupt backing device of device node inode, since file->f_mapping is equal to inode->i_mapping (see __dentry_open() in fs/open.c). Let's introduce separate inode for MTD device with appropriate backing device. [dwmw2: Refactor to keep it all entirely within mtdchar.c; use iget_locked()] Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2010-02-25mtdchar: Register the full range of minor numbersBen Hutchings
register_chrdev() registers minor numbers up to 255, but we can now potentially have much larger numbers. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2010-02-25mtd: Remove unnecessary comparisons with MAX_MTD_DEVICESBen Hutchings
MAX_MTD_DEVICES is about to be removed. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2010-02-25mtd: change positive error return into negativeRoel Kluin
Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2010-02-25mtd: fix different address space noiseH Hartley Sweeten
In mtd_ioctl MEMGETREGIONINFO the region_user_info pointer ur is cast in __kernel space. This produces a number of sparse warnings like: warning: cast removes address space of expression warning: incorrect type in initializer (different address spaces) expected unsigned int const [noderef] <asn:1>*register __p got unsigned int *<noident> Since argp is already a void __user * just use it dirrectly without the cast and make ur a __user *. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-05-29mtd: Fix pointer handling in compat ioctls to use compat_ptr()David Woodhouse
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-05-29mtd: Handle compat ioctls directly; remove all trace from compat_ioctl.cKevin Cernekee
Remove all references to MTD ioctls from fs/compat_ioctl.c and let them all be handled by mtd_compat_ioctl(). Signed-off-by: Kevin Cernekee <kpc.mtd@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-05-29mtd: add OOB ioctls for >4GiB devicesKevin Cernekee
Signed-off-by: Kevin Cernekee <kpc.mtd@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-05-29mtd: compat_ioctl cleanupKevin Cernekee
1) Move the MEMREADOOB/MEMWRITEOOB compat_ioctl wrappers from fs/compat_ioctl.c into mtdchar.c . Original request was here: http://lkml.org/lkml/2009/4/1/295 2) Add missing COMPATIBLE_IOCTL lines, so that mtd-utils does not error out when running in 64/32 compatibility mode. LKML-Reference: <200904011650.22928.arnd@arndb.de> Signed-off-by: Kevin Cernekee <kpc.mtd@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-05-29mtd: add MEMERASE64 ioctl for >4GiB devicesKevin Cernekee
New MEMERASE/MEMREADOOB/MEMWRITEOOB ioctls are needed in order to support 64-bit offsets into large NAND flash devices. Signed-off-by: Kevin Cernekee <kpc.mtd@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-04-04[MTD] driver model updatesDavid Brownell
Update driver model support in the MTD framework, so it fits better into the current udev-based hotplug framework: - Each mtd_info now has a device node. MTD drivers should set the dev.parent field to point to the physical device, before setting up partitions or otherwise declaring MTDs. - Those device nodes always map to /sys/class/mtdX device nodes, which no longer depend on MTD_CHARDEV. - Those mtdX sysfs nodes have a "starter set" of attributes; it's not yet sufficient to replace /proc/mtd. - Enabling MTD_CHARDEV provides /sys/class/mtdXro/ nodes and the /sys/class/mtd*/dev attributes (for udev, mdev, etc). - Include a MODULE_ALIAS_CHARDEV_MAJOR macro. It'll work with udev creating the /dev/mtd* nodes, not just a static rootfs. So the sysfs structure is pretty much what you'd expect, except that readonly chardev nodes are a bit quirky. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-03-24NOMMU: Present backing device capabilities for MTD chardevsDavid Howells
Present backing device capabilities for MTD character device files to allow NOMMU mmap to do direct mapping where possible. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Bernd Schmidt <bernd.schmidt@analog.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-03-20[MTD] Auto-load mtdchar module when device opened.Scott James Remnant
The mtdchar module is missing the char-major-90-* alias that would cause it to be auto-loaded when a device of that type is opened. This patch adds the alia.. Signed-off-by: Scott James Remnant <scott@canonical.com> Signed-off-by: Tim Gardner <tim.gardner@canonical.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2008-12-10[MTD] update internal API to support 64-bit device sizeAdrian Hunter
MTD internal API presently uses 32-bit values to represent device size. This patch updates them to 64-bits but leaves the external API unchanged. Extending the external API is a separate issue for several reasons. First, no one needs it at the moment. Secondly, whether the implementation is done with IOCTLs, sysfs or both is still debated. Thirdly external API changes require the internal API to be accepted first. Note that although the MTD API will be able to support 64-bit device sizes, existing drivers do not and are not required to do so, although NAND base has been updated. In general, changing from 32-bit to 64-bit values cause little or no changes to the majority of the code with the following exceptions: - printk message formats - division and modulus of 64-bit values - NAND base support - 32-bit local variables used by mtdpart and mtdconcat - naughtily assuming one structure maps to another in MEMERASE ioctl Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2008-10-21[PATCH] introduce fmode_t, do annotationsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-20Merge git://git.infradead.org/mtd-2.6Linus Torvalds
* git://git.infradead.org/mtd-2.6: (69 commits) Revert "[MTD] m25p80.c code cleanup" [MTD] [NAND] GPIO driver depends on ARM... for now. [MTD] [NAND] sh_flctl: fix compile error [MTD] [NOR] AT49BV6416 has swapped erase regions [MTD] [NAND] GPIO NAND flash driver [MTD] cmdlineparts documentation change - explain where mtd-id comes from [MTD] cfi_cmdset_0002.c: Add Macronix CFI V1.0 TopBottom detection [MTD] [NAND] Fix compilation warnings in drivers/mtd/nand/cs553x_nand.c [JFFS2] Write buffer offset adjustment for NOR-ECC (Sibley) flash [MTD] mtdoops: Fix a bug where block may not be erased [MTD] mtdoops: Add a magic number to logged kernel oops [MTD] mtdoops: Fix an off by one error [JFFS2] Correct parameter names of jffs2_compress() in comments [MTD] [NAND] sh_flctl: add support for Renesas SuperH FLCTL [MTD] [NAND] Bug on atmel_nand HW ECC : OOB info not correctly written [MTD] [MAPS] Remove unused variable after ROM API cleanup. [MTD] m25p80.c extended jedec support (v2) [MTD] remove unused mtd parameter in of_mtd_parse_partitions() [MTD] [NAND] remove dead Kconfig associated with !CONFIG_PPC_MERGE [MTD] [NAND] driver extension to support NAND on TQM85xx modules ...
2008-10-16device create: misc: convert device_create_drvdata to device_createGreg Kroah-Hartman
Now that device_create() has been audited, rename things back to the original call to be sane. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-09-02[MTD] mtdchar.c: Fix regression in MEMGETREGIONINFO ioctl()Zev Weiss
The MEMGETREGIONINFO ioctl() in mtdchar.c was clobbering user memory by overwriting more than intended, due the size of struct mtd_erase_region_info changing in commit 0ecbc81adfcb9f15f86b05ff576b342ce81bbef8 ('Support for auto locking flash on power up'). Fix avoids this by copying struct members one by one with put_user(), as there is no longer a convenient struct to use the size of as the length argument to copy_to_user(). Signed-off-by: Zev Weiss <zevweiss@gmail.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2008-08-01[MTD] dataflash OTP supportDavid Brownell
Now that we can tell when we have one of the newer DataFlash chips, optionally expose the 128 bytes of OTP memory they provide. Tested on at45db642 revision B and D chips. Switch mtdchar over to a generic HAVE_MTD_OTP flag instead of adding another #ifdef for each type of chip whose driver has OTP support. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Bryan Wu <cooloney@kernel.org> Cc: Michael Hennerich <michael.hennerich@analog.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2008-07-25Merge branch 'linux-next' of git://git.infradead.org/~dedekind/ubi-2.6David Woodhouse
2008-07-21device create: mtd: convert device_create to device_create_drvdataGreg Kroah-Hartman
device_create() is race-prone, so use the race-free device_create_drvdata() instead as device_create() is going away. Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-11[MTD] mtdchar.c remove shadowed variable warningsHarvey Harrison
Use einfo, oinfo for the inner erase_info and otp_info structs used in individual case statements. drivers/mtd/mtdchar.c:582:26: warning: symbol 'info' shadows an earlier one drivers/mtd/mtdchar.c:380:23: originally declared here drivers/mtd/mtdchar.c:596:26: warning: symbol 'info' shadows an earlier one drivers/mtd/mtdchar.c:380:23: originally declared here drivers/mtd/mtdchar.c:704:19: warning: symbol 'info' shadows an earlier one drivers/mtd/mtdchar.c:380:23: originally declared here Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2008-07-11[MTD] mtdchar.c silence sparse warningHarvey Harrison
The copy_to_user was casting away the address space to get the offset of the length member. Use offsetof() instead and add it to the void __user *argp. drivers/mtd/mtdchar.c:527:23: warning: cast removes address space of expression drivers/mtd/mtdchar.c:527:23: warning: incorrect type in argument 1 (different address spaces) drivers/mtd/mtdchar.c:527:23: expected void [noderef] <asn:1>*to drivers/mtd/mtdchar.c:527:23: got unsigned int *<noident> Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2008-06-20mtdchar: cdev lock_kernel() pushdownJonathan Corbet
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2008-06-04MTD/JFFS2: remove CVS keywordsAdrian Bunk
Once upon a time, the MTD repository was using CVS. This patch therefore removes all usages of the no longer updated CVS keywords from the MTD code. This also includes code that printed them to the user. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2008-02-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.gitDavid Woodhouse
2008-01-24mtd: Convert from class_device to device for MTD/mtdcharTony Jones
struct class_device is going away, this converts the code to use struct device instead. Signed-off-by: Tony Jones <tonyj@suse.de> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-08[MTD] mtdchar.c: ioctl always returns 0 as size written for ppc64David Scidmore
"include/linux/mtd/mtd.h" declares "mtd_oob_ops.retlen" as size_t, which is 64 bits on targets with a 64 bit addressing. The MEMWRITEOOB ioctl calls copy_to_user() to write it back to "mtd_oob_buf.length", which is declared in "include/linux/mtd-abi.h" as uint32_t. Since powerpc is a big endian architecture, this only copies the upper 32 bits of the address, which is always 0. Signed-off-by: David Scidmore <dscidmore@xes-inc.com> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2007-08-23Merge branch 'master' of ↵David Woodhouse
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
2007-08-11mtdchar build fixAndrew Morton
sh: drivers/mtd/mtdchar.c: In function `mtd_mmap': drivers/mtd/mtdchar.c:817: error: dereferencing pointer to incomplete type drivers/mtd/mtdchar.c:817: error: `VM_SHARED' undeclared (first use in this function) drivers/mtd/mtdchar.c:817: error: (Each undeclared identifier is reported only once Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-28[MTD] Only call mtd->sync() method in mtdchar close if opened for write.Joakim Tjernlund
Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2007-04-17[MTD] Fix length comparison in MEMREADOOBThomas Gleixner
The ops.len member is not initialized, because it is unused for this operation. The length check needs to use ops.ooblen instead Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2007-02-19Merge git://git.infradead.org/mtd-2.6Linus Torvalds
* git://git.infradead.org/mtd-2.6: (49 commits) [MTD] [NAND] S3C2412 fix hw ecc [MTD] [NAND] Work around false compiler warning in CAFÉ driver [JFFS2] printk warning fixes [MTD] [MAPS] ichxrom warning fix [MTD] [MAPS] amd76xrom warning fix [MTD] [MAPS] esb2rom warning fixes [MTD] [MAPS] ck804xrom warning fix [MTD] [MAPS] netsc520 warning fix [MTD] [MAPS] sc520cdp warning fix [MTD] [ONENAND] onenand_base warning fix [MTD] [NAND] eXcite nand flash driver [MTD] Improve heuristic for detecting wrong-endian RedBoot partition table [MTD] Fix RedBoot partition parsing regression harder. [MTD] [NAND] S3C2410: Hardware ECC correction code [JFFS2] Use MTD_OOB_AUTO to automatically place cleanmarker on NAND [MTD] Clarify OOB-operation interface comments [MTD] remove unused ecctype,eccsize fields from struct mtd_info [MTD] [NOR] Intel: remove ugly PROGREGION macros [MTD] [NOR] STAA: use writesize instead off eccsize to represent ECC block [MTD] OneNAND: Invalidate bufferRAM after erase ...
2007-02-12[PATCH] mark struct file_operations const 5Arjan van de Ven
Many struct file_operations in the kernel can be "const". Marking them const moves these to the .rodata section, which avoids false sharing with potential dirty data. In addition it'll catch accidental writes at compile time to these shared resources. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-09[MTD] remove unused ecctype,eccsize fields from struct mtd_infoArtem Bityutskiy
Remove unused and broken mtd->ecctype and mtd->eccsize fields from struct mtd_info. Do not remove them from userspace API data structures (don't want to breake userspace) but mark them as obsolete by a comment. Any userspace program which uses them should be half-broken anyway, so this is more about saving data structure size. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-11-29[MTD] return error code from get_mtd_device()Artem Bityutskiy
get_mtd_device() returns NULL in case of any failure. Teach it to return an error code instead. Fix all users as well. Signed-off-by: Artem Bityutskiy <dedekind@infradead.org>
2006-11-28[MTD] replace kmalloc+memset with kzallocBurman Yan
Signed-off-by: Yan Burman <yan_952@hotmail.com> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-11-28[MTD] [NAND] remove len/ooblen confusion.Vitaly Wool
As was discussed between Ricard Wanderlöf, David Woodhouse, Artem Bityutskiy and me, the current API for reading/writing OOB is confusing. The thing that introduces confusion is the need to specify ops.len together with ops.ooblen for reads/writes that concern only OOB not data area. So, ops.len is overloaded: when ops.datbuf != NULL it serves to specify the length of the data read, and when ops.datbuf == NULL, it serves to specify the full OOB read length. The patch inlined below is the slightly updated version of the previous patch serving the same purpose, but with the new Artem's comments taken into account. Artem, BTW, thanks a lot for your valuable input! Signed-off-by: Vitaly Wool <vwool@ru.mvista.com> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-10-21[MTD] mtdchar: Fix MEMGETOOBSEL and ECCGETLAYOUT ioctlsRicard Wanderlöf
1. The ECCGETLAYOUT ioctl copy_to_user() call has a superfluous '&' causing the resulting information to be garbage rather than the intended mtd->ecclayout. 2. The MEMGETOOBSEL misses copying mtd->ecclayout->eccbytes so the resulting field of the returned structure contains garbage. Signed-off-by: Ricard Wanderlöf <ricardw@axis.com> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-17[MTD] Use SEEK_{SET,CUR,END} instead of hardcoded values in mtdchar lseek()Josef 'Jeff' Sipek
Signed-off-by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-27[MTD] CORE mtdchar.c: fix off-by-one error in lseek()Herbert Valerio Riedel
Allow lseek(mtdchar_fd, 0, SEEK_END) to succeed, which currently fails with EINVAL. lseek(fd, 0, SEEK_END) should result into the same fileposition as lseek(fd, 0, SEEK_SET) + read(fd, buf, length(fd)) Furthermore, lseek(fd, 0, SEEK_CUR) should return the current file position, which in case of an encountered EOF should not result in EINVAL Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-06-20[MTD] NAND: Fix breakage all over the placeThomas Gleixner
Following problems are addressed: - wrong status caused early break out of nand_wait() - removed the bogus status check in nand_wait() which is a relict of the abandoned support for interrupted erase. - status check moved to the correct place in read_oob - oob support for syndrom based ecc with strange layouts - use given offset in the AUTOOOB based oob operations Partially based on a patch from Vitaly Vool <vwool@ru.mvista.com> Thanks to Savin Zlobec <savin@epico.si> for tracking down the status problem. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2006-05-30[MTD] Disconnect struct mtd_info from ABIJoern Engel
mtdchar.c direcly copied part of struct mtd_info to userspace, thereby implicitly making it part of the ABI. With this patch, struct mtd_info is independent of the ABI and can have its fields removed, reordered, etc. Signed-off-by: Joern Engel <joern@wh.fh-wedel.de>
2006-05-30[MTD] NAND Expose the new raw mode function and status info to userspaceThomas Gleixner
The raw read/write access to NAND (without ECC) has been changed in the NAND rework. Expose the new way - setting the file mode via ioctl - to userspace. Also allow to read out the ecc statistics information so userspace tools can see that bitflips happened and whether errors where correctable or not. Also expose the number of bad blocks for the partition, so nandwrite can check if the data fits into the parition before writing to it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2006-05-29[MTD] NAND Signal that a bitflip was corrected by ECCThomas Gleixner
Return -EUCLEAN on read when a bitflip was detected and corrected, so the clients can react and eventually copy the affected block to a spare one. Make all in kernel users aware of the change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2006-05-29[MTD] Rework the out of band handling completelyThomas Gleixner
Hopefully the last iteration on this! The handling of out of band data on NAND was accompanied by tons of fruitless discussions and halfarsed patches to make it work for a particular problem. Sufficiently annoyed by I all those "I know it better" mails and the resonable amount of discarded "it solves my problem" patches, I finally decided to go for the big rework. After removing the _ecc variants of mtd read/write functions the solution to satisfy the various requirements was to refactor the read/write _oob functions in mtd. The major change is that read/write_oob now takes a pointer to an operation descriptor structure "struct mtd_oob_ops".instead of having a function with at least seven arguments. read/write_oob which should probably renamed to a more descriptive name, can do the following tasks: - read/write out of band data - read/write data content and out of band data - read/write raw data content and out of band data (ecc disabled) struct mtd_oob_ops has a mode field, which determines the oob handling mode. Aside of the MTD_OOB_RAW mode, which is intended to be especially for diagnostic purposes and some internal functions e.g. bad block table creation, the other two modes are for mtd clients: MTD_OOB_PLACE puts/gets the given oob data exactly to/from the place which is described by the ooboffs and ooblen fields of the mtd_oob_ops strcuture. It's up to the caller to make sure that the byte positions are not used by the ECC placement algorithms. MTD_OOB_AUTO puts/gets the given oob data automaticaly to/from the places in the out of band area which are described by the oobfree tuples in the ecclayout data structre which is associated to the devicee. The decision whether data plus oob or oob only handling is done depends on the setting of the datbuf member of the data structure. When datbuf == NULL then the internal read/write_oob functions are selected, otherwise the read/write data routines are invoked. Tested on a few platforms with all variants. Please be aware of possible regressions for your particular device / application scenario Disclaimer: Any whining will be ignored from those who just contributed "hot air blurb" and never sat down to tackle the underlying problem of the mess in the NAND driver grown over time and the big chunk of work to fix up the existing users. The problem was not the holiness of the existing MTD interfaces. The problems was the lack of time to go for the big overhaul. It's easy to add more mess to the existing one, but it takes alot of effort to go for a real solution. Improvements and bugfixes are welcome! Signed-off-by: Thomas Gleixner <tglx@linutronix.de>