For one of the CCI events exposed under sysfs, "snoop" was typo'd as
"snopp". Correct this such that users see the expected event name when
enumerating events via sysfs.

Cc: arm@kernel.org
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Olof Johansson <olof@lixom.net>

Merge "bus: ARM CCN PMU driver updates" from Paweł Moll:

- Fixes and improvements for XP watchpoint and events handling
- Added missing condition checks for KVM-related exclusions
- Improved interrupt affinity handling
- Fix for hrtimer use in polling mode
- Event grouping implementation improvement

* tag 'ccn/fixes-for-4.8-v2' of git://git.linaro.org/people/pawel.moll/linux:
  bus: arm-ccn: make event groups reliable
  bus: arm-ccn: fix hrtimer registration
  bus: arm-ccn: fix PMU interrupt flags
  bus: arm-ccn: Add missing event attribute exclusions for host/guest
  bus: arm-ccn: Correct required arguments for XP PMU events
  bus: arm-ccn: Fix XP watchpoint settings bitmask
  bus: arm-ccn: Do not attempt to configure XPs for cycle counter
  bus: arm-ccn: Fix PMU handling of MN

The CCN PMU driver leaves the counting logic always enabled, and thus
events are enabled while groups are manipulated. As each event is
stopped and read individually, this leads to arbitrary skew across event
groups, which can be seen if counting several identical events.

To avoid this, implement pmu_{enable,disable} callbacks to stop and
start all counters atomically around event manipulation. As the counters
are now stopped, we cannot poll the cycle counter to wait for events to
drain from the bus. However, as the counters are stopped and the events
will not be read regardless, we can simply allow the bus to drain
naturally.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Pawel Moll <pawel.moll@arm.com>

The CCN PMU driver has a single hrtimer, used to simulate a periodic
interrupt on systems where the overflow interrupt is not possible to
use. The hrtimer is started when any event is started, and cancelled when
any event is stopped. Thus, stopping a single event is sufficient to
disable to hrtimer, and overflows (of other events) may be lost.

To avoid this, this patch reworks the hrtimer start/cancel to only occur
when the first event is added to a PMU, and the last event removed,
making use of the existing bitmap counting active events.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Pawel Moll <pawel.moll@arm.com>

Currently the IRQ core is permitted to make the CCN PMU IRQ handler
threaded, and will allow userspace to change the CPU affinity of the
interrupt behind our back. Both of these could violate our
synchronisation requirements with the core perf code, which relies upon
strict CPU affinity and disabling of interrupts to guarantee mutual
exclusion in some cases.

As with the CPU PMU drivers, we should request the interrupt with
IRQF_NOBALANCING and IRQF_NO_THREAD, to avoid these issues.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Pawel Moll <pawel.moll@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Pawel Moll <pawel.moll@arm.com>

CCN PMUs have no knowledge into VM-related origins of the memory
traffic, therefore can't handle requests for host-only or guest-only
events.

Added appropriate exclusions (they should have been there from the
beginning). This required changing the error code returned, as the
userspace tool only re-negotiates the options (exclude_guest is true by
default) only for EINVAL.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>

XP can provide events from two sources: watchpoints, observing traffic
on device ports and PMU looking at internal buses.

Unfortunately the sysfs definition of the PMU events was requiring
port number (instead of bus number) and direction (the buses are
unidirectional), as these fields were shared with the watchpoint event.

Although it does not introduce a major problem (port can be used as
bus alias and direction is simply ignored for XP PMU events), it's
better to fix it now, before external tools start depending on this
behaviour.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>

The code setting XP watchpoint comparator and mask registers should, in
order to be fully compliant with specification, zero one or more most
significant bits of each field. In both L cases it means zeroing bit 63.
The bitmask doing this was wrong, though, zeroing bit 60 instead.
Fortunately, due to a lucky coincidence, this turned out to be fairly
innocent with the existing hardware.

Fixed now.

Cc: stable@vger.kernel.org # 3.17+
Signed-off-by: Pawel Moll <pawel.moll@arm.com>

Fuzzing the CCN perf driver revealed a small but definitely dangerous
mistake in the event setup code. When a cycle counter is requested, the
driver should not reconfigure the events bus at all, otherwise it will
corrupt (in most but the simplest cases) its configuration and may end
up accessing XP array out of its bounds and corrupting control
registers.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Cc: stable@vger.kernel.org # 3.17+
Signed-off-by: Pawel Moll <pawel.moll@arm.com>

The "Miscellaneous Node" fell through cracks of node initialisation,
as its ID is shared with HN-I.

This patch treats MN as a special case (which it is), adding separate
validation check for it and pre-defining the node ID in relevant events
descriptions. That way one can simply run:

	# perf stat -a -e ccn/mn_ecbarrier/ <workload>

Additionally, direction in the MN pseudo-events XP watchpoint
definitions is corrected to be "TX" (1) as they are defined from the
crosspoint point of view (thus barriers are transmitted from XP to MN).

Cc: stable@vger.kernel.org # 3.17+
Signed-off-by: Pawel Moll <pawel.moll@arm.com>