[PATCH 1/2] arm64: adding cpu lookup functionality
From: mark.rutland@arm.com (Mark Rutland)
Date: 2015-02-02 15:37:23
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On Fri, Jan 30, 2015 at 10:54:25PM +0000, mathieu.poirier at linaro.org wrote:
quoted hunk ↗ jump to hunk
From: Mathieu Poirier <mathieu.poirier@linaro.org> Adding a lookup function allowing for quick and easy mapping between processor HWID (as found, for example) in DT specifications and the CPU index known to the kernel. Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> --- arch/arm64/include/asm/smp_plat.h | 12 ++++++++++++ 1 file changed, 12 insertions(+)diff --git a/arch/arm64/include/asm/smp_plat.h b/arch/arm64/include/asm/smp_plat.h index 59e282311b58..8e4b011303b1 100644 --- a/arch/arm64/include/asm/smp_plat.h +++ b/arch/arm64/include/asm/smp_plat.h@@ -19,6 +19,7 @@ #ifndef __ASM_SMP_PLAT_H #define __ASM_SMP_PLAT_H +#include <linux/cpumask.h> #include <asm/types.h> struct mpidr_hash {@@ -40,4 +41,15 @@ static inline u32 mpidr_hash_size(void) extern u64 __cpu_logical_map[NR_CPUS]; #define cpu_logical_map(cpu) __cpu_logical_map[cpu] +static inline int get_logical_index(u64 mpidr) +{ + int cpu; + + for (cpu = 0; cpu < nr_cpu_ids; cpu++) + if (cpu_logical_map(cpu) == mpidr) + return cpu; + return -EINVAL; +}
Are there some pending updates for of_coresight.c that aren't in mainline yet? It looks like even with this the parsing would be broken if /cpus/#address-cells is greater than 1 (as with juno.dts), and it'll just assume CPU0 in that case. It would be nicer if we instead had a CPU node to logical ID mapping function in the core OF code. We already have the inverse with of_get_cpu_node, so I assume the necessary infrastructure is already there. Mark.