treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/tlb: Clean up simple architectures

For the architectures that do not implement their own tlb_flush() but
do already use the generic mmu_gather, there are two options:

1) the platform has an efficient flush_tlb_range() and
asm-generic/tlb.h doesn't need any overrides at all.

2) the platform lacks an efficient flush_tlb_range() and
we select MMU_GATHER_NO_RANGE to minimize full invalidates.

Convert all 'simple' architectures to one of these two forms.

alpha: has no range invalidate -> 2
arc: already used flush_tlb_range() -> 1
c6x: has no range invalidate -> 2
hexagon: has an efficient flush_tlb_range() -> 1
(flush_tlb_mm() is in fact a full range invalidate,
so no need to shoot down everything)
m68k: has inefficient flush_tlb_range() -> 2
microblaze: has no flush_tlb_range() -> 2
mips: has efficient flush_tlb_range() -> 1
(even though it currently seems to use flush_tlb_mm())
nds32: already uses flush_tlb_range() -> 1
nios2: has inefficient flush_tlb_range() -> 2
(no limit on range iteration)
openrisc: has inefficient flush_tlb_range() -> 2
(no limit on range iteration)
parisc: already uses flush_tlb_range() -> 1
sparc32: already uses flush_tlb_range() -> 1
unicore32: has inefficient flush_tlb_range() -> 2
(no limit on range iteration)
xtensa: has efficient flush_tlb_range() -> 1

Note this also fixes a bug in the existing code for a number
platforms. Those platforms that did:

tlb_end_vma() -> if (!full_mm) flush_tlb_*()
tlb_flush -> if (full_mm) flush_tlb_mm()

missed the case of shift_arg_pages(), which doesn't have @fullmm set,
nor calls into tlb_*vma(), but still frees page-tables and thus needs
an invalidate. The new code handles this by detecting a non-empty
range, and either issuing the matching range invalidate or a full
invalidate, depending on the capabilities.

No change in behavior intended.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Piggin <npiggin@gmail.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

OpenRISC: Memory management

Signed-off-by: Jonas Bonn <jonas@southpole.se>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>