[PATCH 1/2] arm64: adding cpu lookup functionality

On 2 February 2015 at 06:50, Will Deacon [off-list ref] wrote:

On Fri, Jan 30, 2015 at 10:54:25PM +0000, mathieu.poirier at linaro.org wrote:

quoted

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;
+}

Can you not achieve the same thing using arch_find_n_match_cpu_physical_id
in the coresight code?

Will

I ended up using "of_get_cpu_node()", which uses
"arch_find_n_match_cpu_physical_id()".  Thanks for pointing this out.

Mathieu