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* ARM64 / ACPI: Parse MADT for SMP initializationHanjun Guo2015-03-251-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MADT contains the information for MPIDR which is essential for SMP initialization, parse the GIC cpu interface structures to get the MPIDR value and map it to cpu_logical_map(), and add enabled cpu with valid MPIDR into cpu_possible_map. ACPI 5.1 only has two explicit methods to boot up SMP, PSCI and Parking protocol, but the Parking protocol is only specified for ARMv7 now, so make PSCI as the only way for the SMP boot protocol before some updates for the ACPI spec or the Parking protocol spec. Parking protocol patches for SMP boot will be sent to upstream when the new version of Parking protocol is ready. CC: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> CC: Catalin Marinas <catalin.marinas@arm.com> CC: Will Deacon <will.deacon@arm.com> CC: Mark Rutland <mark.rutland@arm.com> Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> Tested-by: Yijing Wang <wangyijing@huawei.com> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> Tested-by: Timur Tabi <timur@codeaurora.org> Tested-by: Robert Richter <rrichter@cavium.com> Acked-by: Robert Richter <rrichter@cavium.com> Acked-by: Olof Johansson <olof@lixom.net> Reviewed-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
* arm64: kernel: remove ARM64_CPU_SUSPEND config optionLorenzo Pieralisi2015-01-271-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ARM64_CPU_SUSPEND config option was introduced to make code providing context save/restore selectable only on platforms requiring power management capabilities. Currently ARM64_CPU_SUSPEND depends on the PM_SLEEP config option which in turn is set by the SUSPEND config option. The introduction of CPU_IDLE for arm64 requires that code configured by ARM64_CPU_SUSPEND (context save/restore) should be compiled in in order to enable the CPU idle driver to rely on CPU operations carrying out context save/restore. The ARM64_CPUIDLE config option (ARM64 generic idle driver) is therefore forced to select ARM64_CPU_SUSPEND, even if there may be (ie PM_SLEEP) failed dependencies, which is not a clean way of handling the kernel configuration option. For these reasons, this patch removes the ARM64_CPU_SUSPEND config option and makes the context save/restore dependent on CPU_PM, which is selected whenever either SUSPEND or CPU_IDLE are configured, cleaning up dependencies in the process. This way, code previously configured through ARM64_CPU_SUSPEND is compiled in whenever a power management subsystem requires it to be present in the kernel (SUSPEND || CPU_IDLE), which is the behaviour expected on ARM64 kernels. The cpu_suspend and cpu_init_idle CPU operations are added only if CPU_IDLE is selected, since they are CPU_IDLE specific methods and should be grouped and defined accordingly. PSCI CPU operations are updated to reflect the introduced changes. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Will Deacon <will.deacon@arm.com> Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: Remove unneeded extern keywordGeoff Levand2014-10-031-2/+2
| | | | | | | | | | Function prototypes are never definitions, so remove any 'extern' keyword from the funcion prototypes in cpu_ops.h. Fixes warnings emited by checkpatch. Signed-off-by: Geoff Levand <geoff@infradead.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: kernel: introduce cpu_init_idle CPU operationLorenzo Pieralisi2014-09-121-0/+3
| | | | | | | | | | | | | | | | | The CPUidle subsystem on ARM64 machines requires the idle states implementation back-end to initialize idle states parameter upon boot. This patch adds a hook in the CPU operations structure that should be initialized by the CPU operations back-end in order to provide a function that initializes cpu idle states. This patch also adds the infrastructure to arm64 kernel required to export the CPU operations based initialization interface, so that drivers (ie CPUidle) can use it when they are initialized at probe time. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* ARM: Check if a CPU has gone offlineAshwin Chaugule2014-05-151-0/+2
| | | | | | | | | | | | | | | | PSCIv0.2 adds a new function called AFFINITY_INFO, which can be used to query if a specified CPU has actually gone offline. Calling this function via cpu_kill ensures that a CPU has quiesced after a call to cpu_die. This helps prevent the CPU from doing arbitrary bad things when data or instructions are clobbered (as happens with kexec) in the window between a CPU announcing that it is dead and said CPU leaving the kernel. Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Rob Herring <robh@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: kernel: cpu_{suspend/resume} implementationLorenzo Pieralisi2013-12-161-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Kernel subsystems like CPU idle and suspend to RAM require a generic mechanism to suspend a processor, save its context and put it into a quiescent state. The cpu_{suspend}/{resume} implementation provides such a framework through a kernel interface allowing to save/restore registers, flush the context to DRAM and suspend/resume to/from low-power states where processor context may be lost. The CPU suspend implementation relies on the suspend protocol registered in CPU operations to carry out a suspend request after context is saved and flushed to DRAM. The cpu_suspend interface: int cpu_suspend(unsigned long arg); allows to pass an opaque parameter that is handed over to the suspend CPU operations back-end so that it can take action according to the semantics attached to it. The arg parameter allows suspend to RAM and CPU idle drivers to communicate to suspend protocol back-ends; it requires standardization so that the interface can be reused seamlessly across systems, paving the way for generic drivers. Context memory is allocated on the stack, whose address is stashed in a per-cpu variable to keep track of it and passed to core functions that save/restore the registers required by the architecture. Even though, upon successful execution, the cpu_suspend function shuts down the suspending processor, the warm boot resume mechanism, based on the cpu_resume function, makes the resume path operate as a cpu_suspend function return, so that cpu_suspend can be treated as a C function by the caller, which simplifies coding the PM drivers that rely on the cpu_suspend API. Upon context save, the minimal amount of memory is flushed to DRAM so that it can be retrieved when the MMU is off and caches are not searched. The suspend CPU operation, depending on the required operations (eg CPU vs Cluster shutdown) is in charge of flushing the cache hierarchy either implicitly (by calling firmware implementations like PSCI) or explicitly by executing the required cache maintainance functions. Debug exceptions are disabled during cpu_{suspend}/{resume} operations so that debug registers can be saved and restored properly preventing preemption from debug agents enabled in the kernel. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
* arm64: add CPU_HOTPLUG infrastructureMark Rutland2013-10-251-0/+9
| | | | | | | | | This patch adds the basic infrastructure necessary to support CPU_HOTPLUG on arm64, based on the arm implementation. Actual hotplug support will depend on an implementation's cpu_operations (e.g. PSCI). Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: read enable-method for CPU0Mark Rutland2013-10-251-1/+2
| | | | | | | | | | | | | | | | With the advent of CPU_HOTPLUG, the enable-method property for CPU0 may tells us something useful (i.e. how to hotplug it back on), so we must read it along with all the enable-method for all the other CPUs. Even on UP the enable-method may tell us useful information (e.g. if a core has some mechanism that might be usable for cpuidle), so we should always read it. This patch factors out the reading of the enable method, and ensures that CPU0's enable method is read regardless of whether the kernel is built with SMP support. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: factor out spin-table boot methodMark Rutland2013-10-251-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The arm64 kernel has an internal holding pen, which is necessary for some systems where we can't bring CPUs online individually and must hold multiple CPUs in a safe area until the kernel is able to handle them. The current SMP infrastructure for arm64 is closely coupled to this holding pen, and alternative boot methods must launch CPUs into the pen, where they sit before they are launched into the kernel proper. With PSCI (and possibly other future boot methods), we can bring CPUs online individually, and need not perform the secondary_holding_pen dance. Instead, this patch factors the holding pen management code out to the spin-table boot method code, as it is the only boot method requiring the pen. A new entry point for secondaries, secondary_entry is added for other boot methods to use, which bypasses the holding pen and its associated overhead when bringing CPUs online. The smp.pen.text section is also removed, as the pen can live in head.text without problem. The cpu_operations structure is extended with two new functions, cpu_boot and cpu_postboot, for bringing a cpu into the kernel and performing any post-boot cleanup required by a bootmethod (e.g. resetting the secondary_holding_pen_release to INVALID_HWID). Documentation is added for cpu_operations. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: reorganise smp_enable_opsMark Rutland2013-10-251-0/+33
For hotplug support, we're going to want a place to store operations that do more than bring CPUs online, and it makes sense to group these with our current smp_enable_ops. For cpuidle support, we'll want to group additional functions, and we may want them even for UP kernels. This patch renames smp_enable_ops to the more general cpu_operations, and pulls the definitions out of smp code such that they can be used in UP kernels. While we're at it, fix up instances of the cpu parameter to be an unsigned int, drop the init markings and rename the *_cpu functions to cpu_* to reduce future churn when cpu_operations is extended. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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