From: Dave Martin dave.martin@linaro.org
When the switcher is active, there is no straightforward way to figure out which logical CPU a given physical CPU maps to.
This patch provides a function bL_switcher_get_logical_index(mpidr), which is analogous to get_logical_index().
This function returns the logical CPU on which the specified physical CPU is grouped (or -EINVAL if unknown). If the switcher is inactive or not present, -EUNATCH is returned instead.
Signed-off-by: Dave Martin dave.martin@linaro.org Signed-off-by: Nicolas Pitre nico@linaro.org --- arch/arm/common/bL_switcher.c | 20 ++++++++++++++++++++ arch/arm/include/asm/bL_switcher.h | 2 ++ 2 files changed, 22 insertions(+)
diff --git a/arch/arm/common/bL_switcher.c b/arch/arm/common/bL_switcher.c index f4878a3604..63bbc4f705 100644 --- a/arch/arm/common/bL_switcher.c +++ b/arch/arm/common/bL_switcher.c @@ -532,6 +532,26 @@ static int bL_switcher_halve_cpus(void) return 0; }
+/* Determine the logical CPU a given physical CPU is grouped on. */ +int bL_switcher_get_logical_index(u32 mpidr) +{ + int cpu; + + if (!bL_switcher_active) + return -EUNATCH; + + mpidr &= MPIDR_HWID_BITMASK; + for_each_online_cpu(cpu) { + int pairing = bL_switcher_cpu_pairing[cpu]; + if (pairing == -1) + continue; + if ((mpidr == cpu_logical_map(cpu)) || + (mpidr == cpu_logical_map(pairing))) + return cpu; + } + return -EINVAL; +} + static void bL_switcher_trace_trigger_cpu(void *__always_unused info) { trace_cpu_migrate_current(get_ns(), read_mpidr()); diff --git a/arch/arm/include/asm/bL_switcher.h b/arch/arm/include/asm/bL_switcher.h index 8ada5a885c..1714800fa1 100644 --- a/arch/arm/include/asm/bL_switcher.h +++ b/arch/arm/include/asm/bL_switcher.h @@ -55,6 +55,7 @@ bool bL_switcher_get_enabled(void); void bL_switcher_put_enabled(void);
int bL_switcher_trace_trigger(void); +int bL_switcher_get_logical_index(u32 mpidr);
#else static inline int bL_switcher_register_notifier(struct notifier_block *nb) @@ -70,6 +71,7 @@ static inline int bL_switcher_unregister_notifier(struct notifier_block *nb) static inline bool bL_switcher_get_enabled(void) { return false; } static inline void bL_switcher_put_enabled(void) { } static inline int bL_switcher_trace_trigger(void) { return 0; } +static inline int bL_switcher_get_logical_index(u32 mpidr) { return -EUNATCH; } #endif /* CONFIG_BL_SWITCHER */
#endif