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>

Most of those macros are unused and the used ones just obfuscate
the code. Remove them and fixup all users.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

The nand_oobinfo structure is not fitting the newer error correction
demands anymore. Replace it by struct nand_ecclayout and fixup the users
all over the place. Keep the nand_oobinfo based ioctl for user space
compability reasons.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

The info structure for out of band data was copied into
the mtd structure. Make it a pointer and remove the ability
to set it from userspace. The position of ecc bytes is
defined by the hardware and should not be changed by software.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

The platform structure was lacking an oobinfo field.
The NDFC driver had some remains from another tree.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

A data node might not be in the fraglist; it could be f->metadata.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

We have a type pointer. Make use of it instead of the error prone nand_ids[i]
reference.

The NAND driver used to set default name settings from the chip ID
string for the device. The feature got lost during the rework. Add it back.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

nCE setting can be done when the first command is issued to the device.
We keep the deselect functionality as it makes sense to deassert nCE
when the device becomes idle.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

This allows us to drop another pointer from the struct jffs2_raw_node_ref,
shrinking it to 8 bytes on 32-bit machines (if the TEST_TOTLEN) paranoia
check is turned off, which will be committed soon).
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

Modularize the write function and reorganaize the internal buffer
management. Remove obsolete chip options and fixup all affected
users.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

PCI is faked on these devices by SMM traps. Don't depend on that --
check for the chipset directly instead.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

Bad tglx. No biscuit.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

Removing readv from struct mtd_info broke block2mtd. Remove the
reference and the useless default implementation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Split the core of the read function out and implement
seperate handling functions for software and hardware
ECC.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Add read/write function pointers to struct nand_ecc_ctrl to
prepare the modulaization of nand_read/write functions. The
current implementation handles every type of ecc mode
software/hardware and all kinds of strange ecc placement
schemes in one switch/if construct. Thats too complex to
maintain and too inflexible to expand. Modularization will
also shorten the code pathes of the read/write functions.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

FLASH - especially NAND FLASH - will become less reliable
and bit flips more likely. Add an ECC statistics struct
to struct mtd_info to keep track of this.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Cleanup the code in the oob related functions and
make use of the new NO_READRDY flag.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

The nand driver has a superflous read ready / command
delay in the read functions. This was added to handle
chips which have an automatic read forward. Newer
chips do not have this functionality anymore. Add this
option to avoid the delay / I/O operation. Mark all
large page chips with the new option flag.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

The lock simplifying patch did not move the lock and waitqueue
initialization into the controller allocation patch.
This reinitializes waitqueue and spinlocks also for driver
supplied controller stuctures. Move it into the allocation path.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Print wasted_size in scanned eraseblocks, print range correctly for
summary dirent and inode entries.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

Preallocation of refs is shortly going to be a per-eraseblock thing,
rather than per-filesystem. Add the required argument to the function.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

... to jffs2_free_jeb_node_refs() since that's what it does.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

One more place where we were changing the accounting info without
actually allocating a ref for the lost space...
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

The cmd_ctrl rework lacks some state transition flags.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Cleanup the functions which are not going to change in the
next steps.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Random unthinking 'cleanup' caused debug messages like this:
   Obsoleting node at 0x0006daf4 of len 0x3a4: <7>Dirtying

If messages are continuation of an existing line, they don't need
to be prefixed with KERN_DEBUG.

THINK. Or you will be replaced by a small shell script.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

Another part of the preparation for switching to an array...
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

As the first step towards eliminating the ref->next_phys member and saving
memory by using an _array_ of struct jffs2_raw_node_ref per eraseblock,
stop the write functions from allocating their own refs; have them just
_reserve_ the appropriate number instead. Then jffs2_link_node_ref() can
just fill them in.

Use a linked list of pre-allocated refs in the superblock, for now. Once
we switch to an array, it'll just be a case of extending that array.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

Move the define out of the middle of the code and add an
appropriate comment.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

The previous change of the command / hardware control allows to
remove the write_byte/word functions completely, as their only
user were nand_command and nand_command_lp.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

The hwcontrol function enforced a step by step state machine
for any kind of hardware chip access. Let the hardware driver
know which control bits are set and inform it about a change
of the control lines. Let the hardware driver write out the
command and address bytes directly. This gives a peformance
advantage for address bus controlled chips and simplifies the
quirks in the hardware drivers.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

The previous _ecc removal / cleanup broke (i)nftl module usage.
Export the missing symbol.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>