• Lorenzo Pieralisi's avatar
    arm64: kernel: remove ARM64_CPU_SUSPEND config option · af3cfdbf
    Lorenzo Pieralisi authored
    
    
    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: default avatarLorenzo 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: default avatarCatalin Marinas <catalin.marinas@arm.com>
    af3cfdbf
proc.S 5.86 KB