perf: Remove the nmi parameter from the swevent and overflow interface

The nmi parameter indicated if we could do wakeups from the current
context, if not, we would set some state and self-IPI and let the
resulting interrupt do the wakeup.

For the various event classes:

  - hardware: nmi=0; PMI is in fact an NMI or we run irq_work_run from
    the PMI-tail (ARM etc.)
  - tracepoint: nmi=0; since tracepoint could be from NMI context.
  - software: nmi=[0,1]; some, like the schedule thing cannot
    perform wakeups, and hence need 0.

As one can see, there is very little nmi=1 usage, and the down-side of
not using it is that on some platforms some software events can have a
jiffy delay in wakeup (when arch_irq_work_raise isn't implemented).

The up-side however is that we can remove the nmi parameter and save a
bunch of conditionals in fast paths.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Michael Cree <mcree@orcon.net.nz>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/n/tip-agjev8eu666tvknpb3iaj0fg@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
static void p4_pmu_disable_pebs(void)
{
	/*
	 * FIXME
	 *
	 * It's still allowed that two threads setup same cache
	 * events so we can't simply clear metrics until we knew
	 * no one is depending on us, so we need kind of counter
	 * for "ReplayEvent" users.
	 *
	 * What is more complex -- RAW events, if user (for some
	 * reason) will pass some cache event metric with improper
	 * event opcode -- it's fine from hardware point of view
	 * but completely nonsense from "meaning" of such action.
	 *
	 * So at moment let leave metrics turned on forever -- it's
	 * ok for now but need to be revisited!
	 *
	 * (void)checking_wrmsrl(MSR_IA32_PEBS_ENABLE, (u64)0);
	 * (void)checking_wrmsrl(MSR_P4_PEBS_MATRIX_VERT, (u64)0);
	 */
}

static void p4_pmu_disable_pebs(void)
{
	/*
	 * FIXME
	 *
	 * It's still allowed that two threads setup same cache
	 * events so we can't simply clear metrics until we knew
	 * no one is depending on us, so we need kind of counter
	 * for "ReplayEvent" users.
	 *
	 * What is more complex -- RAW events, if user (for some
	 * reason) will pass some cache event metric with improper
	 * event opcode -- it's fine from hardware point of view
	 * but completely nonsense from "meaning" of such action.
	 *
	 * So at moment let leave metrics turned on forever -- it's
	 * ok for now but need to be revisited!
	 *
	 * (void)checking_wrmsrl(MSR_IA32_PEBS_ENABLE, (u64)0);
	 * (void)checking_wrmsrl(MSR_P4_PEBS_MATRIX_VERT, (u64)0);
	 */
}
