Blackfin arch: defines and provides entry points for certain user space functions at fixed addresses

This patch defines (and provides) entry points for certain user space functions
at fixed addresses.  The Blackfin has no usable atomic instructions, but we can
ensure that these code sequences appear atomic from a user space point of view
by detecting when we're in the process of executing them during the interrupt
handler return path.  This allows much more efficient pthread lock
implementations than the bfin_spinlock syscall we're currently using.

Also provided is a small sys_rt_sigreturn stub which can be used by the signal
handler setup code.  The signal.c part will be committed separately.
Signed-off-by: NBernd Schmidt <bernd.schmidt@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

The ADSP-BF54x was specifically designed to meet the needs of convergent multimedia
applications where system performance and cost are essential ingredients. The
integration of multimedia, human interface, and connectivity peripherals combined
with increased system bandwidth and on-chip memory provides customers a platform to
design the most demanding applications.

Since now, ADSP-BF54x will be supported in the Linux kernel and bunch of related drivers
such as USB OTG, ATAPI, NAND flash controller, LCD framebuffer, sound, touch screen will
be submitted later.

Please enjoy the show.
Signed-off-by: NRoy Huang <roy.huang@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Add silicon revision "any" and "none". Add proper -mcpu option according
to the cpu and silicon revision configuration.

Need update to use latest Blackfin cross compile toolchain.
Signed-off-by: NJie Zhang <jie.zhang@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>

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

Signed-off-by: NAubrey Li <aubrey.li@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>

Blackfin arch: cache SWRST value at bootup so other things like watchdog can non-destructively query it
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>

Blackfin arch: move board specific setup out of common init code and into the board specific init code
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>

Without conswitchp preset, we have the following situation:

 - During initcalls: con_init is called, and returns because of
   !display_desc.

 - At this point there is no memory allocated for vc_cons[].d
   A bit later vty_init calls kbd_init.

 - From now on events are passed to kbd_event which will then call
   kbd_keycode.

 - kbd_keycode will oops on a NULL pointer dereference on vc->vc_tty
Signed-off-by: NMichael Hennerich <michael.hennerich@analog.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>
[ Added commit description based on email thread. - Linus ]
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>