Perf has three ways to name a PMU: either by passing an explicit char *,
reading arm_pmu->name or accessing arm_pmu->pmu.name.
Just use arm_pmu->name consistently in the ARM backend.
Signed-off-by: Will Deacon <will.deacon@arm.com>
The arm_pmu functions have wildly varied parameters which can often be
derived from struct perf_event.
This patch changes the arm_pmu function prototypes so that struct
perf_event pointers are passed in preference to fields that can be
derived from the event.
Signed-off-by: Sudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This patch moves the CPU-specific IRQ registration and parsing code into
the CPU PMU backend. This is required because a PMU may have more than
one interrupt, which in turn can be either PPI (per-cpu) or SPI
(requiring strict affinity setting at the interrupt distributor).
Signed-off-by: Sudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com>
[will: cosmetic edits and reworked interrupt dispatching]
Signed-off-by: Will Deacon <will.deacon@arm.com>
The CPU PMU code is tightly coupled with generic ARM PMU handling code.
This makes it cumbersome when trying to add support for other ARM PMUs
(e.g. interconnect, L2 cache controller, bus) as the generic parts of
the code are not readily reusable.
This patch cleans up perf_event.c so that reusable code is exposed via
header files to other potential PMU drivers. The CPU code is
consistently named to identify it as such and also to prepare for moving
it into a separate file.
Signed-off-by: Will Deacon <will.deacon@arm.com>
The arm_pmu_type enumeration was initially introduced to identify
different PMU types in the system, the usual one being that on the CPU
(ARM_PMU_DEVICE_CPU). With the removal of the PMU reservation code and
the introduction of devicetree bindings for the CPU PMU, the enumeration
is no longer required.
This patch removes the enumeration and updates the various CPU PMU
platform devices so that they no longer pass an .id field referring
to identify the PMU type.
Cc: Haojian Zhuang <haojian.zhuang@gmail.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Pawel Moll <pawel.moll@arm.com>
Acked-by: Jon Hunter <jon-hunter@ti.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jiandong Zheng <jdzheng@broadcom.com>
Signed-off-by: Sudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com>
[will: cosmetic edits and actual removal of the enum type]
Signed-off-by: Will Deacon <will.deacon@arm.com>
The PMU reservation mechanism was originally intended to allow OProfile
and perf-events to co-ordinate over access to the CPU PMU. Since then,
OProfile for ARM has moved to using perf as its backend, so the
reservation code is no longer used.
This patch removes the reservation code for the CPU PMU on ARM.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Add runtime PM support to the ARM PMU driver so that devices such as OMAP
supporting dynamic PM can use the platform->runtime_* hooks to initialise
hardware at runtime. Without having these runtime PM hooks in place any
configuration of the PMU hardware would be lost when low power states are
entered and hence would prevent PMU from working.
This change also replaces the PMU platform functions enable_irq and disable_irq
added by Ming Lei with runtime_resume and runtime_suspend funtions. Ming had
added the enable_irq and disable_irq functions as a method to configure the
cross trigger interface on OMAP4 for routing the PMU interrupts. By adding
runtime PM support, we can move the code called by enable_irq and disable_irq
into the runtime PM callbacks runtime_resume and runtime_suspend.
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Benoit Cousson <b-cousson@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Kevin Hilman <khilman@ti.com>
Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
In order to provide PMU name strings compatible with the OProfile
user ABI, an enumeration of all PMUs is currently used by perf to
identify each PMU uniquely. Unfortunately, this does not scale well
in the presence of multiple PMUs and creates a single, global namespace
across all PMUs in the system.
This patch removes the enumeration and instead uses the name string
for the PMU to map onto the OProfile variant. perf_pmu_name is
implemented for CPU PMUs, which is all that OProfile cares about anyway.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
On ARM, the PMU does not stop counting after an overflow and therefore
IRQ latency affects the new counter value read by the kernel. This is
significant for non-sampling runs where it is possible for the new value
to overtake the previous one, causing the delta to be out by up to
max_period events.
Commit a737823d ("ARM: 6835/1: perf: ensure overflows aren't missed due
to IRQ latency") attempted to fix this problem by allowing interrupt
handlers to pass an overflow flag to the event update function, causing
the overflow calculation to assume that the counter passed through zero
when going from prev to new. Unfortunately, this doesn't work when
overflow occurs on the perf_task_tick path because we have the flag
cleared and end up computing a large negative delta.
This patch removes the overflow flag from armpmu_event_update and
instead limits the sample_period to half of the max_period for
non-sampling profiling runs.
Cc: <stable@vger.kernel.org>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch introduces .enable_irq and .disable_irq into
struct arm_pmu_platdata, so platform specific irq enablement
can be handled after request_irq, and platform specific irq
disablement can be handled before free_irq.
This patch is for support of pmu irq routed from CTI on omap4.
Acked-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
pmu_init no longer exists, so don't declare it in asm/pmu.h.
Reported-by: Pawel Moll <Pawel.Moll@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Currently, struct arm_pmu and related functions are only visible to
{,arch/arm/}/kernel/perf_event.c. This prevents new drivers from using
the framework.
This patch moves declarations to asm/pmu.h, allowing new PMU drivers
to use the framework.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Once upon a time, OProfile and Perf fought hard over who could play with
the PMU. To stop all hell from breaking loose, pmu.c offered an internal
reserve/release API and took care of parsing PMU platform data passed in
from board support code.
Now that Perf has ingested OProfile, let's move the platform device
handling into the Perf driver and out of the PMU locking code.
Unfortunately, the lock has to remain to prevent Perf being bitten by
out-of-tree modules such as LTTng, which still claim a right to the PMU
when Perf isn't looking.
Acked-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Commit f12482c9 ("ARM: 6974/1: pmu: refactor reservation") changed
{release,reserve}_pmu to take an enum arm_pmu_type as a parameter, but
inconsistently named the parameter `type' or `device'. It would be nice
if these were consistent.
This patch makes use of enum arm_pmu_type consistent, always using
`type'. Related printks are updated, explicitly mentioning `type' also.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Commit f12482c9 ("ARM: 6974/1: pmu: refactor reservation") changed the
prototype of release_pmu, but missed the stub for when
CONFIG_CPU_HAS_PMU is not selected by the platform.
This patch changes the prototype of the stub, preventing possible build
failures when CONFIG_CPU_HAS_PMU is not selected.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Currently, PMU platform_device reservation relies on some minor abuse
of the platform_device::id field for determining the type of PMU. This
is problematic for device tree based probing, where the ID cannot be
controlled.
This patch removes reliance on the id field, and depends on each PMU's
platform driver to figure out which type it is. As all PMUs handled by
the current platform_driver name "arm-pmu" are CPU PMUs, this
convention is hardcoded. New PMU types can be supported through the use
of {of,platform}_device_id tables
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Allow a platform-specific IRQ handler to be specified via platform data.
This will be used to implement the single-irq workaround for the DB8500.
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The current PMU infrastructure for ARM requires that the IRQs for the PMU
device are fixed at compile time and are selected based on the ARCH_ or MACH_ flags. This has the disadvantage of tying the Kernel down to a
particular board as far as profiling is concerned.
This patch replaces the compile-time IRQ registration with a runtime mechanism which allows the IRQs to be registered with the framework as
a platform_device.
A further advantage of this change is that there is scope for registering
different types of performance counters in the future by changing the id
of the platform_device and attaching different resources to it.
Acked-by: Jamie Iles <jamie.iles@picochip.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch adds an enum describing the potential PMU device types in
preparation for PMU device registration via platform devices.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
To add support for perf events and to allow the hardware counters to be
shared with oprofile, we need a way to reserve access to the pmu
(performance monitor unit). Platforms with PMU interrupts should
register the interrupts in arch/arm/kernel/pmu.c
Signed-off-by: Jamie Iles <jamie.iles@picochip.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Will Deacon