Fixed-purpose counters stopped working in a simple 'perf stat ls' run:

   <not counted>  cache references
   <not counted>  cache misses

Due to:

  ef7b3e09: perf_counter, x86: remove vendor check in fixed_mode_idx()

Which made x86_pmu.num_counters_fixed matter: if it's nonzero, the
fixed-purpose counters are utilized.

But on v2 perfmon this field is not set (despite there being
fixed-purpose PMCs). So add a quirk to set the number of fixed-purpose
counters to at least three.

[ Impact: add quirk for three fixed-purpose counters on certain Intel CPUs ]

Cc: Robert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-28-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Invert the atomic_inc_not_zero() test so that we will indeed detect the
first activation.

Also rename the global num_counters, since its easy to confuse with
x86_pmu.num_counters.

[ Impact: fix non-working perfcounters on AMD CPUs, cleanup ]
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241455664.7620.4938.camel@twins>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

When we don't have any perf-counters active, don't act like we know
what the NMI is for.

[ Impact: fix hard hang with nmi_watchdog=2 ]
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090501102533.109867793@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Standardize on explicitly mentioning '_mask' in fields that
are not plain flags but masks. This avoids typos like:

       if (cpuc->used)

(which could easily slip through review unnoticed), while if a
typo looks like this:

       if (cpuc->used_mask)

it might get noticed during review.

[ Impact: cleanup ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1241016956-24648-1-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The mask argument is unused and thus can be removed.

[ Impact: cleanup ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-29-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The function fixed_mode_idx() is used generically. Now it checks the
num_counters_fixed value instead of the vendor to decide if fixed
counters are present.

[ Impact: generalize code ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-28-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

In x86 pmus the allowed counter period to programm differs. This
introduces a max_period value and allows the generic implementation
for all models to check the max period.

[ Impact: generalize code ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-27-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

To check on AMD cpus if a counter overflows, the upper bit of the raw
counter value must be checked. This value is already internally
available in x86_perf_counter_update(). Now, the value is returned so
that it can be used directly to check for overflows.

[ Impact: micro-optimization ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-26-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch implements the interrupt handler for AMD performance
counters. In difference to the Intel pmu, there is no single status
register and also there are no fixed counters. This makes the handler
very different and it is useful to make the handler vendor
specific. To check if a counter is overflowed the upper bit of the
counter is checked. Only counters where the active bit is set are
checked.

With this patch throttling is enabled for AMD performance counters.

This patch also reenables Linux performance counters on AMD cpus.

[ Impact: re-enable perfcounters on AMD CPUs ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-25-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Some functions are only called if the pmu was proper initialized. That
initalization checks can be removed. The way to check initialization
changed too. Now, the pointer to the interrupt handler is checked. If
it exists the pmu is initialized. This also removes a static variable
and uses struct x86_pmu as only data source for the check.

[ Impact: simplify code ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-24-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

As for the enable function, this patch reworks the disable functions
and introduces x86_pmu_disable_counter(). The internal function i/f in
struct x86_pmu changed too.

[ Impact: refactor and generalize code ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-23-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

There is vendor specific code in generic x86 code, and there is vendor
specific code that could be generic. This patch introduces
x86_pmu_enable_counter() for x86 generic code. Fixed counter code for
Intel is moved to Intel only functions. In the end, checks and calls
via function pointers were reduced to the necessary. Also, the
internal function i/f changed.

[ Impact: refactor and generalize code ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-22-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The type of counter index is sometimes implemented as unsigned
int. This patch changes this to have a consistent usage of int.

[ Impact: cleanup ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-21-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

cpuc->active will now be used to indicate an enabled counter which
implies also valid pointers of cpuc->counters[]. In contrast,
cpuc->used only locks the counter, but it can be still uninitialized.

[ Impact: refactor and generalize code ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-20-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This is to have a consistent naming scheme with cpuc->used.

[ Impact: cleanup ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-19-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

[ Impact: micro-optimization ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-18-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This makes the use of the version variable generic. Also, some debug
messages have been generalized.

[ Impact: refactor and generalize code ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-17-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

[ Impact: refactor and generalize code ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-16-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Instead of using a pointer to reference to the x86 pmu we now have one
single data structure that is initialized at the beginning. This saves
the pointer access when using this memory.

[ Impact: micro-optimization ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-15-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch adds an error handler and changes initialization of struct
x86_pmu. No functional changes. Needed for follow-on patches.

[ Impact: cleanup ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-14-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

[ Impact: cleanup ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-13-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

[ Impact: cleanup ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-12-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This function is Intel only and not necessary for AMD cpus.

[ Impact: simplify code ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-11-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This function is Intel only and not necessary for AMD cpus.

[ Impact: simplify code ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-10-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This separates the perfcounter interrupt handler for AMD and Intel
cpus. The AMD interrupt handler implementation is a follow-on patch.

[ Impact: refactor and clean up code ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-9-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch renames struct pmc_x86_ops into struct x86_pmu. It
introduces a structure to describe an x86 model specific pmu
(performance monitoring unit). It may contain ops and data. The new
name of the structure fits better, is shorter, and thus better to
handle. Where it was appropriate, names of function and variable have
been changed too.

[ Impact: cleanup ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-8-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch renames struct hw_perf_counter_ops into struct pmu. It
introduces a structure to describe a cpu specific pmu (performance
monitoring unit). It may contain ops and data. The new name of the
structure fits better, is shorter, and thus better to handle. Where it
was appropriate, names of function and variable have been changed too.

[ Impact: cleanup ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-7-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Per-cpu variables needn't to be protected with cpu barriers
(smp_wmb()). Protection is only needed for preemption on the same cpu
(rescheduling or the nmi handler). This can be done using a compiler
barrier only.

[ Impact: micro-optimization ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-6-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

MSR reads and writes are expensive. This patch adds checks to avoid
its usage where possible.

[ Impact: micro-optimization on AMD CPUs ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-5-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This quits hw counter initialization immediately if no cpu is
detected.

[ Impact: cleanup ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-4-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

X86_FEATURE_ARCH_PERFMON is an Intel hardware feature that does not
work on AMD CPUs. The flag is now only used in Intel specific code
(especially initialization).

[ Impact: refactor code ]
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1241002046-8832-2-git-send-email-robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Paul suggested we allow for data addresses to be recorded along with
the traditional IPs as power can provide these.

For now, only the software pagefault events provide data addresses,
but in the future power might as well for some events.

x86 doesn't seem capable of providing this atm.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090408130409.394816925@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Prepare for more generic overflow handling. The new perf_counter_overflow()
method will handle the generic bits of the counter overflow, and can return
a !0 return value, in which case the counter should be (soft) disabled, so
that it won't count until it's properly disabled.

XXX: do powerpc and swcounter
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090406094517.812109629@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Implement set_perf_counter_pending() with a self-IPI so that it will
run ASAP in a usable context.

For now use a second IRQ vector, because the primary vector pokes
the apic in funny ways that seem to confuse things.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090406094517.724626696@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Put in counts to tell which ips belong to what context.

  -----
   | |  hv
   | --
nr | |  kernel
   | --
   | |  user
  -----
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Orig-LKML-Reference: <20090402091319.493101305@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Follow the example set by powerpc and try to play nice with oprofile
and the nmi watchdog.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NPaul Mackerras <paulus@samba.org>
Orig-LKML-Reference: <20090330171024.459968444@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Provide the x86 perf_callchain() implementation.

Code based on the ftrace/sysprof code from Soeren Sandmann Pedersen.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NPaul Mackerras <paulus@samba.org>
Cc: Soeren Sandmann Pedersen <sandmann@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Orig-LKML-Reference: <20090330171024.341993293@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Now that Paul cleaned up the error propagation paths, pass down the
x86 error as well.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NPaul Mackerras <paulus@samba.org>
Orig-LKML-Reference: <20090330171023.792822360@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

While going over the wakeup code I noticed delayed wakeups only work
for hardware counters but basically all software counters rely on
them.

This patch unifies and generalizes the delayed wakeup to fix this
issue.

Since we're dealing with NMI context bits here, use a cmpxchg() based
single link list implementation to track counters that have pending
wakeups.

[ This should really be generic code for delayed wakeups, but since we
  cannot use cmpxchg()/xchg() in generic code, I've let it live in the
  perf_counter code. -- Eric Dumazet could use it to aggregate the
  network wakeups. ]

Furthermore, the x86 method of using TIF flags was flawed in that its
quite possible to end up setting the bit on the idle task, loosing the
wakeup.

The powerpc method uses per-cpu storage and does appear to be
sufficient.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NPaul Mackerras <paulus@samba.org>
Orig-LKML-Reference: <20090330171023.153932974@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>