treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 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 version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

MIPS, Perf-events: Work with irq_work

This is the MIPS part of the following commit by Peter Zijlstra:

- e360adbe29241a0194e10e20595360dd7b98a2b3
irq_work: Add generic hardirq context callbacks

Provide a mechanism that allows running code in IRQ context. It is
most useful for NMI code that needs to interact with the rest of the
system -- like wakeup a task to drain buffers.

Perf currently has such a mechanism, so extract that and provide it as
a generic feature, independent of perf so that others may also
benefit.

The IRQ context callback is generated through self-IPIs where
possible, or on architectures like powerpc the decrementer (the
built-in timer facility) is set to generate an interrupt immediately.

Architectures that don't have anything like this get to do with a
callback from the timer tick. These architectures can call
irq_work_run() at the tail of any IRQ handlers that might enqueue such
work (like the perf IRQ handler) to avoid undue latencies in
processing the work.

For MIPSXX, we need to call irq_work_run() at the tail of the perf IRQ
handler as described above.

Reported-by: Wu Zhangjin <wuzhangjin@gmail.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
To: fweisbec@gmail.com
To: will.deacon@arm.com
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: paulus@samba.org
Cc: mingo@elte.hu
Cc: acme@redhat.com
Cc: matt@console-pimps.org
Cc: sshtylyov@mvista.com,
Patchwork: http://patchwork.linux-mips.org/patch/2011/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: add support for hardware performance events (skeleton)

This patch provides the skeleton of the HW perf event support. To enable
this feature, we can not choose the SMTC kernel; Oprofile should be
disabled; kernel performance events be selected. Then we can enable it in
Kernel type menu.

Oprofile for MIPS platforms initializes irq at arch init time. Currently
we do not change this logic to allow PMU reservation.

If a platform has EIC, we can use the irq base and perf counter irq offset
defines for the interrupt controller in specific init_hw_perf_events().

Based on this skeleton patch, the 3 different kinds of MIPS PMU, namely,
mipsxx/loongson2/rm9000, can be supported by adding corresponding lower
level C files at the bottom. The suggested names of these files are
perf_event_mipsxx.c/perf_event_loongson2.c/perf_event_rm9000.c. So, for
example, we can do this by adding "#include perf_event_mipsxx.c" at the
bottom of perf_event.c.

In addition, PMUs with 64bit counters are also considered in this patch.

Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
To: linux-mips@linux-mips.org
Cc: a.p.zijlstra@chello.nl
Cc: paulus@samba.org
Cc: mingo@elte.hu
Cc: acme@redhat.com
Cc: jamie.iles@picochip.com
Cc: ddaney@caviumnetworks.com
Cc: matt@console-pimps.org
Patchwork: https://patchwork.linux-mips.org/patch/1688/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>