diff options
Diffstat (limited to 'arch/arm/include/asm/mcpm.h')
-rw-r--r-- | arch/arm/include/asm/mcpm.h | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/arch/arm/include/asm/mcpm.h b/arch/arm/include/asm/mcpm.h index fc82a88f5b69..608516ebabfe 100644 --- a/arch/arm/include/asm/mcpm.h +++ b/arch/arm/include/asm/mcpm.h @@ -42,6 +42,14 @@ extern void mcpm_entry_point(void); void mcpm_set_entry_vector(unsigned cpu, unsigned cluster, void *ptr); /* + * This sets an early poke i.e a value to be poked into some address + * from very early assembly code before the CPU is ungated. The + * address must be physical, and if 0 then nothing will happen. + */ +void mcpm_set_early_poke(unsigned cpu, unsigned cluster, + unsigned long poke_phys_addr, unsigned long poke_val); + +/* * CPU/cluster power operations API for higher subsystems to use. */ @@ -81,10 +89,40 @@ int mcpm_cpu_power_up(unsigned int cpu, unsigned int cluster); * * This will return if mcpm_platform_register() has not been called * previously in which case the caller should take appropriate action. + * + * On success, the CPU is not guaranteed to be truly halted until + * mcpm_cpu_power_down_finish() subsequently returns non-zero for the + * specified cpu. Until then, other CPUs should make sure they do not + * trash memory the target CPU might be executing/accessing. */ void mcpm_cpu_power_down(void); /** + * mcpm_cpu_power_down_finish - wait for a specified CPU to halt, and + * make sure it is powered off + * + * @cpu: CPU number within given cluster + * @cluster: cluster number for the CPU + * + * Call this function to ensure that a pending powerdown has taken + * effect and the CPU is safely parked before performing non-mcpm + * operations that may affect the CPU (such as kexec trashing the + * kernel text). + * + * It is *not* necessary to call this function if you only need to + * serialise a pending powerdown with mcpm_cpu_power_up() or a wakeup + * event. + * + * Do not call this function unless the specified CPU has already + * called mcpm_cpu_power_down() or has committed to doing so. + * + * @return: + * - zero if the CPU is in a safely parked state + * - nonzero otherwise (e.g., timeout) + */ +int mcpm_cpu_power_down_finish(unsigned int cpu, unsigned int cluster); + +/** * mcpm_cpu_suspend - bring the calling CPU in a suspended state * * @expected_residency: duration in microseconds the CPU is expected @@ -126,6 +164,7 @@ int mcpm_cpu_powered_up(void); struct mcpm_platform_ops { int (*power_up)(unsigned int cpu, unsigned int cluster); void (*power_down)(void); + int (*power_down_finish)(unsigned int cpu, unsigned int cluster); void (*suspend)(u64); void (*powered_up)(void); }; |