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>
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>
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>
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>
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>
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>
MTD clients are agnostic of FLASH which needs ECC suppport.
Remove the functions and fixup the callers.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
First step of modularizing ECC support.
- Move ECC related functionality into a seperate embedded data structure
- Get rid of the hardware dependend constants to simplify new ECC models
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Seperate functionality out of nand_scan so the code is more
readable. No functional change. First step of simplifying
the nand driver.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The NAND driver used a mix of unsigned char, u_char amd uint8_t
data types. Consolidate to uint8_t usage
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The writev based write buffer implementation was far to complex as
in most use cases the write buffer had to be handled anyway.
Simplify the write buffer handling and use mtd->write instead.
From extensive testing no performance impact has been noted.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Replace the chip lock by a the controller lock. For simple drivers a
dummy controller structure is created by the scan code.
This simplifies the locking algorithm in nand_get/release_chip().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Unrolling the loops produces denser and much faster code.
Add a config switch which allows to select the byte order of the
resulting ecc code. The current Linux implementation has a byte
swap versus the SmartMedia specification
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We don't need the upper layers to deal with the physical offset. It's
_always_ c->nextblock->offset + c->sector_size - c->nextblock->free_size
so we might as well just let the actual write functions deal with that.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
o Add a flag MTD_BIT_WRITEABLE for devices that allow single bits to be
cleared.
o Replace MTD_PROGRAM_REGIONS with a cleared MTD_BIT_WRITEABLE flag for
STMicro and Intel Sibley flashes with internal ECC. Those flashes
disallow clearing of single bits, unlike regular NOR flashes, so the
new flag models their behaviour better.
o Remove MTD_ECC. After the STMicro/Sibley merge, this flag is only set
and never checked.
Signed-off-by: Joern Engel <joern@wh.fh-wedel.de>
In 2002, STMicro started producing NOR flashes with internal ECC protection
for small blocks (8 or 16 bytes). Support for those flashes was added by me.
In 2005, Intel Sibley flashes copied this strategy and Nico added support for
those. Merge the code for both.
Signed-off-by: Joern Engel <joern@wh.fh-wedel.de>
At least two flashes exists that have the concept of a minimum write unit,
similar to NAND pages, but no other NAND characteristics. Therefore, rename
the minimum write unit to "writesize" for all flashes, including NAND.
Signed-off-by: Joern Engel <joern@wh.fh-wedel.de>
Two flags exist to decide whether a device is writeable or not. None of
those two flags is checked for independently, so they are clearly redundant,
if not an invitation to bugs. This patch removed both of them, replacing
them with a single new flag.
Signed-off-by: Joern Engel <joern@wh.fh-wedel.de>
We'll be using a proper list of nodes in the jffs2_xattr_datum and
jffs2_xattr_ref structures, because the existing code to overwrite
them is just broken. Put it in the common part at the front of the
structure which is shared with the jffs2_inode_cache, so that the
jffs2_link_node_ref() function can do the right thing.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
In a couple of places, we assume that what's at the end of the
->next_in_ino list is a struct jffs2_inode_cache. Let's check
for that, since we expect it to change soon.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Let's avoid the potential for forgetting to set ref->next_in_ino, by doing
it within jffs2_link_node_ref() instead.
This highlights the ugliness of what we're currently doing with
xattr_datum and xattr_ref structures -- we should find a nicer way of
dealing with that.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
When filing REF_OBSOLETE nodes, we'd add their size to the global
'dirty_size' count, but then to the eraseblock's 'used_size' count.
That's not clever.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
