This patch separates the PMU driver code from the low level
CCI driver code and enables the PMU driver for ARM64.
Introduces config options for both.
ARM_CCI400_PORT_CTRL - controls the low level driver code for
CCI400 ports.
ARM_CCI400_PMU - controls the PMU driver code
ARM_CCI400_COMMON - Common defintions for CCI400
This patch also changes:
ARM_CCI - common code for probing the CCI devices. This can be
used for adding support for newer CCI versions(e.g, CCI-500).
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Abhilash Kesavan <a.kesavan@samsung.com>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Punit Agrawal <punit.agrawal@arm.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Avoid secure transactions while probing the CCI PMU. The
existing code makes use of the Peripheral ID2 (PID2) register
to determine the revision of the CCI400, which requires a
secure transaction. This puts a limitation on the usage of the
driver on systems running non-secure Linux(e.g, ARM64).
Updated the device-tree binding for cci pmu node to add the explicit
revision number for the compatible field.
The supported strings are :
arm,cci-400-pmu,r0
arm,cci-400-pmu,r1
arm,cci-400-pmu - DEPRECATED. See NOTE below
NOTE: If the revision is not mentioned, we need to probe the cci revision,
which could be fatal on a platform running non-secure. We need a reliable way
to know if we can poke the CCI registers at runtime on ARM32. We depend on
'mcpm_is_available()' when it is available. mcpm_is_available() returns true
only when there is a registered driver for mcpm. Otherwise, we assume that we
don't have secure access, and skips probing the revision number(ARM64 case).
The MCPM should figure out if it is safe to access the CCI. Unfortunately
there isn't a reliable way to indicate the same via dtb. This patch doesn't
address/change the current situation. It only deals with the CCI-PMU, leaving
the assumptions about the secure access as it has been, prior to this patch.
Cc: devicetree@vger.kernel.org
Cc: Punit Agrawal <punit.agrawal@arm.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
On ARM multi-cluster systems coherency between cores running on
different clusters is managed by the cache-coherent interconnect (CCI).
It allows broadcasting of TLB invalidates and memory barriers and it
guarantees cache coherency at system level through snooping of slave
interfaces connected to it.
This patch enables the basic infrastructure required in Linux to handle and
programme the CCI component.
Non-local variables used by the CCI management functions called by power
down function calls after disabling the cache must be flushed out to main
memory in advance, otherwise incoherency of those values may occur if they
are sitting in the cache of some other CPU when power down functions
execute. Driver code ensures that relevant data structures are flushed
from inner and outer caches after the driver probe is completed.
CCI slave port resources are linked to set of CPUs through bus masters
phandle properties that link the interface resources to masters node in
the device tree.
Documentation describing the CCI DT bindings is provided with the patch.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Suzuki K. Poulose