This patch adds checks to the nmi handler. Now samples are only
generated and counters reenabled, if the counters are running.
Otherwise the counters are stopped, if oprofile is using the nmi. In
other cases it will ignore the nmi notification.

Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This patch reworks oprofile cpu hotplug code as follows:

Introduce ctr_running variable to check, if counters are running or
not. The state must be known for taking a cpu on or offline and when
switching counters during counter multiplexing.

Protect on_each_cpu() sections with get_online_cpus()/put_online_cpu()
functions. This is necessary if notifiers or states are
modified. Within these sections the cpu mask may not change.

Switch only between counters in nmi_cpu_switch(), if counters are
running. Otherwise the switch may restart a counter though they are
disabled.

Add nmi_cpu_setup() and nmi_cpu_shutdown() to cpu hotplug code. The
function must also be called to avoid uninitialzed counter usage.

Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

CPU notifier register functions also exist if CONFIG_SMP is
disabled. This change is part of hotplug code rework and also
necessary for later patches.

Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This fixes a NULL pointer dereference that is triggered when taking a
cpu offline after oprofile was initialized, e.g.:

 $ opcontrol --init
 $ opcontrol --start-daemon
 $ opcontrol --shutdown
 $ opcontrol --deinit
 $ echo 0 > /sys/devices/system/cpu/cpu1/online

See the crash dump below. Though the counter has been disabled the cpu
notifier is still active and trying to use already freed counter data.

This fix is for linux-stable. To proper fix this, the hotplug code
must be rewritten. Thus I will leave a WARN_ON_ONCE() message with
this patch.

BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff8132ad57>] op_amd_stop+0x2d/0x8e
PGD 0
Oops: 0000 [#1] SMP
last sysfs file: /sys/devices/system/cpu/cpu1/online
CPU 1
Modules linked in:

Pid: 0, comm: swapper Not tainted 2.6.34-rc5-oprofile-x86_64-standard-00210-g8c00f06 #16 Anaheim/Anaheim
RIP: 0010:[<ffffffff8132ad57>]  [<ffffffff8132ad57>] op_amd_stop+0x2d/0x8e
RSP: 0018:ffff880001843f28  EFLAGS: 00010006
RAX: 0000000000000000 RBX: 0000000000000000 RCX: dead000000200200
RDX: ffff880001843f68 RSI: dead000000100100 RDI: 0000000000000000
RBP: ffff880001843f48 R08: 0000000000000000 R09: ffff880001843f08
R10: ffffffff8102c9a5 R11: ffff88000184ea80 R12: 0000000000000000
R13: ffff88000184f6c0 R14: 0000000000000000 R15: 0000000000000000
FS:  00007fec6a92e6f0(0000) GS:ffff880001840000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000000 CR3: 000000000163b000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper (pid: 0, threadinfo ffff88042fcd8000, task ffff88042fcd51d0)
Stack:
 ffff880001843f48 0000000000000001 ffff88042e9f7d38 ffff880001843f68
<0> ffff880001843f58 ffffffff8132a602 ffff880001843f98 ffffffff810521b3
<0> ffff880001843f68 ffff880001843f68 ffff880001843f88 ffff88042fcd9fd8
Call Trace:
 <IRQ>
 [<ffffffff8132a602>] nmi_cpu_stop+0x21/0x23
 [<ffffffff810521b3>] generic_smp_call_function_single_interrupt+0xdf/0x11b
 [<ffffffff8101804f>] smp_call_function_single_interrupt+0x22/0x31
 [<ffffffff810029f3>] call_function_single_interrupt+0x13/0x20
 <EOI>
 [<ffffffff8102c9a5>] ? wake_up_process+0x10/0x12
 [<ffffffff81008701>] ? default_idle+0x22/0x37
 [<ffffffff8100896d>] c1e_idle+0xdf/0xe6
 [<ffffffff813f1170>] ? atomic_notifier_call_chain+0x13/0x15
 [<ffffffff810012fb>] cpu_idle+0x4b/0x7e
 [<ffffffff813e8a4e>] start_secondary+0x1ae/0x1b2
Code: 89 e5 41 55 49 89 fd 41 54 45 31 e4 53 31 db 48 83 ec 08 89 df e8 be f8 ff ff 48 98 48 83 3c c5 10 67 7a 81 00 74 1f 49 8b 45 08 <42> 8b 0c 20 0f 32 48 c1 e2 20 25 ff ff bf ff 48 09 d0 48 89 c2
RIP  [<ffffffff8132ad57>] op_amd_stop+0x2d/0x8e
 RSP <ffff880001843f28>
CR2: 0000000000000000
---[ end trace 679ac372d674b757 ]---
Kernel panic - not syncing: Fatal exception in interrupt
Pid: 0, comm: swapper Tainted: G      D    2.6.34-rc5-oprofile-x86_64-standard-00210-g8c00f06 #16
Call Trace:
 <IRQ>  [<ffffffff813ebd6a>] panic+0x9e/0x10c
 [<ffffffff810474b0>] ? up+0x34/0x39
 [<ffffffff81031ccc>] ? kmsg_dump+0x112/0x12c
 [<ffffffff813eeff1>] oops_end+0x81/0x8e
 [<ffffffff8101efee>] no_context+0x1f3/0x202
 [<ffffffff8101f1b7>] __bad_area_nosemaphore+0x1ba/0x1e0
 [<ffffffff81028d24>] ? enqueue_task_fair+0x16d/0x17a
 [<ffffffff810264dc>] ? activate_task+0x42/0x53
 [<ffffffff8102c967>] ? try_to_wake_up+0x272/0x284
 [<ffffffff8101f1eb>] bad_area_nosemaphore+0xe/0x10
 [<ffffffff813f0f3f>] do_page_fault+0x1c8/0x37c
 [<ffffffff81028d24>] ? enqueue_task_fair+0x16d/0x17a
 [<ffffffff813ee55f>] page_fault+0x1f/0x30
 [<ffffffff8102c9a5>] ? wake_up_process+0x10/0x12
 [<ffffffff8132ad57>] ? op_amd_stop+0x2d/0x8e
 [<ffffffff8132ad46>] ? op_amd_stop+0x1c/0x8e
 [<ffffffff8132a602>] nmi_cpu_stop+0x21/0x23
 [<ffffffff810521b3>] generic_smp_call_function_single_interrupt+0xdf/0x11b
 [<ffffffff8101804f>] smp_call_function_single_interrupt+0x22/0x31
 [<ffffffff810029f3>] call_function_single_interrupt+0x13/0x20
 <EOI>  [<ffffffff8102c9a5>] ? wake_up_process+0x10/0x12
 [<ffffffff81008701>] ? default_idle+0x22/0x37
 [<ffffffff8100896d>] c1e_idle+0xdf/0xe6
 [<ffffffff813f1170>] ? atomic_notifier_call_chain+0x13/0x15
 [<ffffffff810012fb>] cpu_idle+0x4b/0x7e
 [<ffffffff813e8a4e>] start_secondary+0x1ae/0x1b2
------------[ cut here ]------------
WARNING: at /local/rrichter/.source/linux/arch/x86/kernel/smp.c:118 native_smp_send_reschedule+0x27/0x53()
Hardware name: Anaheim
Modules linked in:
Pid: 0, comm: swapper Tainted: G      D    2.6.34-rc5-oprofile-x86_64-standard-00210-g8c00f06 #16
Call Trace:
 <IRQ>  [<ffffffff81017f32>] ? native_smp_send_reschedule+0x27/0x53
 [<ffffffff81030ee2>] warn_slowpath_common+0x77/0xa4
 [<ffffffff81030f1e>] warn_slowpath_null+0xf/0x11
 [<ffffffff81017f32>] native_smp_send_reschedule+0x27/0x53
 [<ffffffff8102634b>] resched_task+0x60/0x62
 [<ffffffff8102653a>] check_preempt_curr_idle+0x10/0x12
 [<ffffffff8102c8ea>] try_to_wake_up+0x1f5/0x284
 [<ffffffff8102c986>] default_wake_function+0xd/0xf
 [<ffffffff810a110d>] pollwake+0x57/0x5a
 [<ffffffff8102c979>] ? default_wake_function+0x0/0xf
 [<ffffffff81026be5>] __wake_up_common+0x46/0x75
 [<ffffffff81026ed0>] __wake_up+0x38/0x50
 [<ffffffff81031694>] printk_tick+0x39/0x3b
 [<ffffffff8103ac37>] update_process_times+0x3f/0x5c
 [<ffffffff8104dc63>] tick_periodic+0x5d/0x69
 [<ffffffff8104dc90>] tick_handle_periodic+0x21/0x71
 [<ffffffff81018fd0>] smp_apic_timer_interrupt+0x82/0x95
 [<ffffffff81002853>] apic_timer_interrupt+0x13/0x20
 [<ffffffff81030cb5>] ? panic_blink_one_second+0x0/0x7b
 [<ffffffff813ebdd6>] ? panic+0x10a/0x10c
 [<ffffffff810474b0>] ? up+0x34/0x39
 [<ffffffff81031ccc>] ? kmsg_dump+0x112/0x12c
 [<ffffffff813eeff1>] ? oops_end+0x81/0x8e
 [<ffffffff8101efee>] ? no_context+0x1f3/0x202
 [<ffffffff8101f1b7>] ? __bad_area_nosemaphore+0x1ba/0x1e0
 [<ffffffff81028d24>] ? enqueue_task_fair+0x16d/0x17a
 [<ffffffff810264dc>] ? activate_task+0x42/0x53
 [<ffffffff8102c967>] ? try_to_wake_up+0x272/0x284
 [<ffffffff8101f1eb>] ? bad_area_nosemaphore+0xe/0x10
 [<ffffffff813f0f3f>] ? do_page_fault+0x1c8/0x37c
 [<ffffffff81028d24>] ? enqueue_task_fair+0x16d/0x17a
 [<ffffffff813ee55f>] ? page_fault+0x1f/0x30
 [<ffffffff8102c9a5>] ? wake_up_process+0x10/0x12
 [<ffffffff8132ad57>] ? op_amd_stop+0x2d/0x8e
 [<ffffffff8132ad46>] ? op_amd_stop+0x1c/0x8e
 [<ffffffff8132a602>] ? nmi_cpu_stop+0x21/0x23
 [<ffffffff810521b3>] ? generic_smp_call_function_single_interrupt+0xdf/0x11b
 [<ffffffff8101804f>] ? smp_call_function_single_interrupt+0x22/0x31
 [<ffffffff810029f3>] ? call_function_single_interrupt+0x13/0x20
 <EOI>  [<ffffffff8102c9a5>] ? wake_up_process+0x10/0x12
 [<ffffffff81008701>] ? default_idle+0x22/0x37
 [<ffffffff8100896d>] ? c1e_idle+0xdf/0xe6
 [<ffffffff813f1170>] ? atomic_notifier_call_chain+0x13/0x15
 [<ffffffff810012fb>] ? cpu_idle+0x4b/0x7e
 [<ffffffff813e8a4e>] ? start_secondary+0x1ae/0x1b2
---[ end trace 679ac372d674b758 ]---

Cc: Andi Kleen <andi@firstfloor.org>
Cc: stable <stable@kernel.org>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

In case a counter is already reserved by the watchdog or perf_event
subsystem, oprofile ignored this counters silently. This case is
handled now and oprofile_setup() now reports an error.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This patch improves the error handler in nmi_setup(). Most parts of
the code are moved to allocate_msrs(). In case of an error
allocate_msrs() also frees already allocated memory. nmi_setup()
becomes easier and better extendable.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

Cc: stable@kernel.org
Signed-off-by: NRobert Richter <robert.richter@amd.com>

Multiple virtual counters share one physical counter. The reservation
of virtual counters fails due to duplicate allocation of the same
counter. The counters are already reserved. Thus, virtual counter
reservation may removed at all. This also makes the code easier.

Cc: stable@kernel.org
Signed-off-by: NRobert Richter <robert.richter@amd.com>

Add Xeon 7500 series support to oprofile.

Straight forward: it's the same as Core i7, so just detect
the model number. No user space changes needed.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

With multiplexing enabled oprofile crashs when profiling more than 28
events. This patch fixes this.
Signed-off-by: NSuravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This patch adds a check for the availability of a counter. A virtual
counter is used only if its physical counter is not reserved.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This patch implements a common x86 function to convert virtual counter
numbers to physical.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This patch moves the multiplexing switch counter from x86 code to
common oprofile statistic variables. Now the value will be available
and usable for all architectures. The initialization and
incrementation also moved to common code.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

To setup a counter for all cpus, its structure is cloned from cpu
0. This patch implements mux_clone() to do this part for multiplexing
data.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This patch checks if the model supports multiplexing. Only then
multiplexing will be enabled. The code is added to the common x86
initialization.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

The check is used to prevent running multiplexing code for models not
supporting multiplexing. Before, the code was running but without
effect.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

Models that do not yet support counter multiplexing have to setup
num_virt_counters. This patch implements the setup from num_counters
if num_virt_counters is not set. Thus, num_virt_counters must be setup
only for multiplexing support.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This patch removes the const qualifier from struct
op_x86_model_spec to make model parameters changable.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This patch moves some code in nmi_int.c to get a single separate
multiplexing code section.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This patch moves some code in nmi_int.c to get a single separate
multiplexing code section.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This patch moves some code in nmi_int.c to get a single separate
multiplexing code section.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This patch implements nmi_setup_mux() and nmi_shutdown_mux() functions
to setup/shutdown multiplexing. Multiplexing code in nmi_int.c is now
much more separated.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This new function translates physical to virtual counter numbers.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

Variable switch_index must be initialized for each cpu. This patch
fixes the initialization by moving it to the per-cpu init function
nmi_cpu_setup().
Signed-off-by: NRobert Richter <robert.richter@amd.com>

__get_cpu_var() calls smp_processor_id(). When the cpu id is already
known, instead use per_cpu() to avoid generating the id again.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

The number of hardware counters is limited. The multiplexing feature
enables OProfile to gather more events than counters are provided by
the hardware. This is realized by switching between events at an user
specified time interval.

A new file (/dev/oprofile/time_slice) is added for the user to specify
the timer interval in ms. If the number of events to profile is higher
than the number of hardware counters available, the patch will
schedule a work queue that switches the event counter and re-writes
the different sets of values into it. The switching mechanism needs to
be implemented for each architecture to support multiplexing. This
patch only implements AMD CPU support, but multiplexing can be easily
extended for other models and architectures.

There are follow-on patches that rework parts of this patch.
Signed-off-by: NJason Yeh <jason.yeh@amd.com>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This patch fixes whitespace changes of code that will be touched in
follow-on patches.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This patch removes the function nmi_save_registers(). Per-cpu code is
now executed only in the function nmi_cpu_setup().  Also, it renames
the per-cpu function nmi_restore_registers() to
nmi_cpu_restore_registers().
Signed-off-by: NRobert Richter <robert.richter@amd.com>

The short name of the achitecture is 'arch_perfmon'. This patch
changes the kernel parameter to use this name.

Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Commit:

 e419294e x86/oprofile: moving arch_perfmon counter setup to op_x86_model_spec.init

introduced a bug in the initialization of core_i7 leading to the
incorrect model setup to &op_ppro_spec. This patch fixes this.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

The patch removes some local variables in these functions.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This patch removes struct op_saved_msr and replaces it by an u64
variable. This makes code easier and it is possible to use 64 bit MSR
functions.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This patch introduces op_x86_get_ctrl() to calculate the value of the
performance control register. This is generic code usable for all
models. The event and reserved masks are model specific and stored in
struct op_x86_model_spec. 64 bit MSR functions are used now. The patch
removes many hard to read macros used for ctrl calculation.

The function op_x86_get_ctrl() is common code and the first step to
further merge performance counter implementations for x86 models.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

In follow-on patches the setup_ctrs() functions will need data that
describes the model. This patch extends the function argument list to
pass a pointer of the model to these function.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

Signed-off-by: NRobert Richter <robert.richter@amd.com>

The function arch_perfmon_init() in nmi_int.c is model specific. This
patch moves it to op_model_ppro.c by using the init function pointer
in struct op_x86_model_spec.

Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This patch removes module_param oprofile.force_arch_perfmon and
introduces oprofile.cpu_type=archperfmon instead. This new parameter
can be reused for other models and architectures.

Currently only archperfmon is supported.

Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

The registers are about the same as other Family 6 CPUs
so we only need to add detection.

I'm not completely happy with calling Nehalem Core i7 because
there will be undoubtedly other Nehalem based CPUs
in the future with different marketing names, but it's
the best we got for now.

Requires updated oprofile userland for the new event files.

If you don't want to update right now you can also use
oprofile.force_arch_perfmon=1 (added in the next patch) with 0.9.4
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

There are no new P4s and the oprofile code knows about all existing
ones, so we don't really need the p4force option anymore.

Remove it.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This re-adds the force_arch_perfmon option that was in the original
arch perfmon patchkit. Originally this was rejected in favour
of a generalized perfmon=name option, but it turned out implementing
the later in a reliable way is hard (and it would have been easy
to crash the kernel if a user gets it wrong)

But now Atom and Core i7 support being readded a user would
need to update their oprofile userland to beyond 0.9.4 to use oprofile again
on Atom or Core i7.

To avoid this problem readd the force_arch_perfmon option.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NRobert Richter <robert.richter@amd.com>