[RFC PATCH 0/3 v3] perf: Add Intel Nehalem uncore pmu support

[Lin Ming <ming.m.lin@intel.com>]

Hi, all

Here are the v3 patches to add uncore pmu support to perf, applied on
top of current tip/master(74f6deb).

Changelogs of v3:

- Allocate uncore data with kmalloc_node, like AMD NB stuff. (Peter
Zijlstra)

- per-task uncore event is not allowed. Simply set pmu::task_ctx_nr =
perf_invalid_context. (Peter Zijlstra)

- Route interrupts to the first core that accesses uncore pmu. (Stephane
Eranian)

- Check CPUID signatures with boot_cpu_data. (Andi Kleen)

- Remove unneeded include files. (Andi Kleen)

Changelogs of v2:

- modify the NMI handling code to handle all counters enabled by all 4
cores.

- allocate uncore_events[] table dynamically using kmalloc_node() to
avoid unnecessary remote memory accesses. (Stephane Eranian)

- add support for the fixed uncore counter. (Stephane Eranian)

- Handling of exclude_* bits. Uncore PMU measures at all privilege level
all the time. So it doesn't make sense to specify any exclude bits.
(Stephane Eranian)

- let uncore code be more self contained, that is, not include it in
arch/x86/kernel/cpu/perf_event.c (Peter Zijlstra)

- uncore pmu interrupt have its own NMI_DIE notifier entry. (Peter
Zijlstra)

Known bugs:

- When hyper thread is enabled, both HTs will receive the NMI. In this
case, the overflow status bits are not acked correctly.

TODO:

- Add support for uncore address/opcode match thing

- Add a new sub-command for uncore events statistics.
For example, perf package -p <package-id> -e <event>

As usual, any comment is very appreciated.

Lin Ming