lwn.git - Linux kernel documentation tree maintained by Jonathan Corbet

Age	Commit message (Collapse)	Author
2015-03-27	arm-cci: Get rid of secure transactions for PMU driver	Suzuki K. Poulose
	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>
2013-09-17	ARM: dts: Document the CCI PMU DT bindings	Punit Agrawal
	The CCI PMU can profile bus transactions at the master and slave interfaces of the CCI. The PMU can be used to observe an aggregated view of the bus traffic between the various components connected to the CCI. Introduce a binding for the CCI PMU. The PMU node will be a sub-node of the CCI node. Cc: devicetree@vger.kernel.org Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Rob Herring <rob.herring@calxeda.com> Acked-by: Stephen Warren <swarren@nvidia.com> Acked-by: Kumar Gala <galak@codeaurora.org> Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2013-09-17	ARM: dts: Improve CCI bindings documentation	Punit Agrawal
	Improve the description of the value types used in the CCI binding. Cc: devicetree@vger.kernel.org Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Rob Herring <rob.herring@calxeda.com> Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2013-05-29	drivers: bus: add ARM CCI support	Lorenzo Pieralisi
	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>