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>

powerpc/perf: increase the perf HW events to 6

This change is required after the e6500 perf support has been added.
There are 6 counters in e6500 core instead of 4 in e500 core and
the MAX_HWEVENTS counter should be changed accordingly from 4 to 6.
Added also runtime check for counters overflow.

Signed-off-by: Catalin Udma <catalin.udma@freescale.com>
Signed-off-by: Lijun Pan <Lijun.Pan@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>

powerpc/perf: e500 support

This implements perf_event support for the Freescale embedded performance
monitor, based on the existing perf_event.c that supports server/classic
chips.

Some limitations:
- Performance monitor interrupts are regular EE interrupts, and thus you
can't profile places with interrupts disabled. We may want to implement
soft IRQ-disabling, with perfmon interrupts exempted and treated as NMIs.
- When trying to schedule multiple event groups at once, and using
restricted events, situations could arise where scheduling fails even
though it would be possible. Consider three groups, each with two events.
One group has restricted events, the others don't. The two non-restricted
groups are scheduled, then one is removed, which happens to occupy the two
counters that can't do restricted events. The remaining non-restricted
group will not be moved to the non-restricted-capable counters to make
room if the restricted group tries to be scheduled.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>