treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 397

Based on 1 normalized pattern(s):

this program is free software you can distribute it and or modify it
under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope it will be useful but without any warranty
without even the implied warranty of merchantability or fitness for
a particular purpose see the gnu general public license for more
details you should have received a copy of the gnu general public
license along with this program if not write to the free software
foundation inc 51 franklin st fifth floor boston ma 02110 1301 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 33 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531081038.563233189@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

MIPS: math-emu: Add IEEE Std 754-2008 ABS.fmt and NEG.fmt emulation

Implement IEEE Std 754-2008 non-arithmetic ABS.fmt and NEG.fmt emulation
wired to the state of the FCSR.ABS2008 bit. In the non-arithmetic mode
the sign bit is altered according to the operation requested regardless
of the datum encoded in the input operand, no other bits are changed,
the resulting bit pattern is written to the output operand and no
exception is ever signalled.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11476/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: math-emu: Make ABS.fmt and NEG.fmt arithmetic again

The ABS.fmt and NEG.fmt instructions have been specified as arithmetic
in the MIPS architecture, which in particular implies handling NaN data
in the usual way with qNaN bit patterns propagated unchanged and sNaN
bit patterns signalling the usual IEEE 754 Invalid Operation exception
and quieted by default.

A series of changes applied over time to our implementation:

c5033d78 [MIPS] ieee754[sd]p_neg workaround
cea2be44 MIPS: Fix abs.[sd] and neg.[sd] emulation for NaN operands

has led to the current situation where the sign bit is updated according
to the operation requested even for NaN inputs. This is according to
these commits a workaround so that broken binaries produced by GCC
disregarding the properties of these instructions have a chance to work.

For sNaN inputs this remains within IEEE Std 754 as the standard leaves
the choice of output qNaN bit patterns produced under the default
Invalid Operation exception handling for individual sNaN input bit
patterns to implementer's discretion, even though it still recommends as
much NaN input information to be preserved in NaN outputs.

For qNaN inputs however it violates the standard as it requires a qNaN
input bit patterns to propagate unchanged to output.

This is also unlike real MIPS FPU hardware behaves where sNaN and/or
qNaN processing has been fully implemented with no Unimplemented
Operation exception signalled. Such hardware propagates any input qNaN
bit pattern unchanged. It also quiets any input sNaN bit pattern in an
implementer-specific manner, for example the MIPS 74Kf processor returns
the default qNaN pattern with the sign bit always clear and the Broadcom
SB-1 and BMIPS5000 processors propagate the input sNaN bit pattern with
the sign bit unchanged and the quiet bit first cleared in the trailing
significand field and then the next lower bit set if clearing the quiet
bit left the field with no other bit set.

Especially the latter observation indicates the limited usefulness of
the workaround as it will cover many hardware configurations, but not
all of them, only making it harder to discover such broken binaries that
need to be recompiled with GCC told to avoid the use of ABS.fmt and
NEG.fmt instructions where non-arithmetic semantics is required by the
algorithm used.

Revert the damage done by the series of changes then, and take the
opportunity to simplify implementation by calling `ieee754dp_sub' and
`ieee754dp_add' as required and also the rounding mode set towards -Inf
temporarily so that the sign of 0 is correctly handled.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9710/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: math-emu: Cleanup coding style.

o Only define variables in the outermost block
o One empty line at most
o Format comments as per CodingStyle
o Update FSF address in licensing term comment
o Spell FPU and MIPS in all capitals.
o Remove ####-type of lines in comments.
o Try to make things a bit most consistent between sp_*.c / dp_*.c files.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: math-emu: Get rid of the useless parts of exception handling.

All it really did was throw a printk for no obvious reason.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: math-emu: Remove unused code.

Shrinks the FPU emulator by 4528 bytes.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: math-emu: Inline ieee754dp_finite and ieee754dp_finite().

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: math-emu: Turn macros into functions where possible.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: math-emu: Get rid of typedefs.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Update broken web addresses in arch directory.

The patch below updates broken web addresses in the arch directory.

Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Finn Thain <fthain@telegraphics.com.au>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Reviewed-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

MIPS: Restore signalling NaN behaviour for abs.[sd]

Atsushi Nemoto <anemo@mba.ocn.ne.jp> spotted that this had been incorrectly
removed in a previous patch

Signed-off-by: Chris Dearman <chris@mips.com>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/1213/
Tested-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Fix abs.[sd] and neg.[sd] emulation for NaN operands

This patch ensures that the sign bit is always updated for NaN operands.

Signed-off-by: Chris Dearman <chris@mips.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

[MIPS] ieee754[sd]p_neg workaround

It looks glibc's pow() assumes an unary '-' operation for any number
(including NaNs) always inverts its sign bit (though IEEE754 does not
specify the sign bit for NaNs). This patch make the kernel math-emu
emulates real MIPS neg.[ds] instruction.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!