This fixes two things:
 - stop calling write_lock_irq/write_unlock_irq which can turn modify
   irq levels
 - don't calling mmput when handing exceptions - since this might_sleep,
   which does a rti, and leaves us in kernel space (irq15, rather
   than irq5).
Signed-off-by: NRobin Getz <robin.getz@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

We must balance calls to get_task_mm with corresponding mmput calls, otherwise
refcounting is screwed up and mms don't get freed when their task exits.
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Blackfin arch: Enable earlyprintk earlier - so any error after our interrupt tables are set up will print out

Also ensure that the traps_c code doesn't cause a double fault, by
sending a signal to a faulting kernel before the memory subsystem
is fully initialized, by printing out the error message before sending
the signal.
Signed-off-by: NRobin Getz <robin.getz@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Today when a double fault happens (exception during an exception
handling event), we go into an endless loop, with nothing comming out
the UART. With this patch, we actually see that we have commited a
double fault event
Signed-off-by: NRobin Getz <robin.getz@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

add an exception request/free api similar to the interrupt request/fre
api so people can utilize the free software based exceptions for their
own purposes
Signed-off-by: NMike Frysinger <michael.frysinger@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Signed-off-by: NMike Frysinger <michael.frysinger@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Add ability to expend the hardware trace buffer via a configurable
software buffer - so you can have lots of history when a crash occurs.

The interesting way we do printk in the traps.c confusese the checking
script
Signed-off-by: NRobin Getz <robin.getz@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Signed-off-by: NSonic Zhang <sonic.zhang@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

we converted to using a system call for userspace spinlocks
rather than a dedicated exception long ago
Signed-off-by: NMike Frysinger <michael.frysinger@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Signed-off-by: NMike Frysinger <michael.frysinger@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Signed-off-by: NRobin Getz <robin.getz@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Turns on trace earlier, so crashes at kernel start should print out a
trace, making things easier to debug.
Signed-off-by: NRobin Getz <robin.getz@analog.com>
Signed-off-by: NMike Frysinger <michael.frysinger@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

to look like:

return address: [0x0357fcc4]; contents of:
0x0357fca0:  fcbc  0357  fe20  0357  0009  0000  6a8c  0345
0x0357fcb0:  000e  0000  fcc4  0357  fd44  0357  e128  00ad
0x0357fcc0:  00a0  0000 [000e] 0000  0000  0000  0080  0000
0x0357fcd0:  0000  0000  0000  0000  00a0  0000  000e  0000

instruction in [] is the offending instruction
Signed-off-by: NRobin Getz <robin.getz@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Signed-off-by: NSimon Arlott <simon@fire.lp0.eu>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Signed-off-by: NMike Frysinger <michael.frysinger@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This adds support for the Analog Devices Blackfin processor architecture, and
currently supports the BF533, BF532, BF531, BF537, BF536, BF534, and BF561
(Dual Core) devices, with a variety of development platforms including those
avaliable from Analog Devices (BF533-EZKit, BF533-STAMP, BF537-STAMP,
BF561-EZKIT), and Bluetechnix!  Tinyboards.

The Blackfin architecture was jointly developed by Intel and Analog Devices
Inc.  (ADI) as the Micro Signal Architecture (MSA) core and introduced it in
December of 2000.  Since then ADI has put this core into its Blackfin
processor family of devices.  The Blackfin core has the advantages of a clean,
orthogonal,RISC-like microprocessor instruction set.  It combines a dual-MAC
(Multiply/Accumulate), state-of-the-art signal processing engine and
single-instruction, multiple-data (SIMD) multimedia capabilities into a single
instruction-set architecture.

The Blackfin architecture, including the instruction set, is described by the
ADSP-BF53x/BF56x Blackfin Processor Programming Reference
http://blackfin.uclinux.org/gf/download/frsrelease/29/2549/Blackfin_PRM.pdf

The Blackfin processor is already supported by major releases of gcc, and
there are binary and source rpms/tarballs for many architectures at:
http://blackfin.uclinux.org/gf/project/toolchain/frs There is complete
documentation, including "getting started" guides available at:
http://docs.blackfin.uclinux.org/ which provides links to the sources and
patches you will need in order to set up a cross-compiling environment for
bfin-linux-uclibc

This patch, as well as the other patches (toolchain, distribution,
uClibc) are actively supported by Analog Devices Inc, at:
http://blackfin.uclinux.org/

We have tested this on LTP, and our test plan (including pass/fails) can
be found at:
http://docs.blackfin.uclinux.org/doku.php?id=testing_the_linux_kernel

[m.kozlowski@tuxland.pl: balance parenthesis in blackfin header files]
Signed-off-by: NBryan Wu <bryan.wu@analog.com>
Signed-off-by: NMariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: NAubrey Li <aubrey.li@analog.com>
Signed-off-by: NJie Zhang <jie.zhang@analog.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>