blackfin architecture

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: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: Aubrey Li <aubrey.li@analog.com>
Signed-off-by: Jie Zhang <jie.zhang@analog.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/asm-blackfin/l1layout.h b/include/asm-blackfin/l1layout.h
new file mode 100644
index 0000000..c13ded7
--- /dev/null
+++ b/include/asm-blackfin/l1layout.h
@@ -0,0 +1,31 @@
+/*
+ * l1layout.h
+ * Defines a layout of L1 scratchpad memory that userspace can rely on.
+ */
+
+#ifndef _L1LAYOUT_H_
+#define _L1LAYOUT_H_
+
+#include <asm/blackfin.h>
+
+#ifndef __ASSEMBLY__
+
+/* Data that is "mapped" into the process VM at the start of the L1 scratch
+   memory, so that each process can access it at a fixed address.  Used for
+   stack checking.  */
+struct l1_scratch_task_info
+{
+	/* Points to the start of the stack.  */
+	void *stack_start;
+	/* Not updated by the kernel; a user process can modify this to
+	   keep track of the lowest address of the stack pointer during its
+	   runtime.  */
+	void *lowest_sp;
+};
+
+/* A pointer to the structure in memory.  */
+#define L1_SCRATCH_TASK_INFO ((struct l1_scratch_task_info *)L1_SCRATCH_START)
+
+#endif
+
+#endif