arm64: kernel: add MPIDR_EL1 accessors macros

In order to simplify access to different affinity levels within the
MPIDR_EL1 register values, this patch implements some preprocessor
macros that allow to retrieve the MPIDR_EL1 affinity level value according
to the level passed as input parameter.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index 5fe138e..e371936 100644 (file)
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -30,6 +30,16 @@
 
 #define MPIDR_HWID_BITMASK     0xff00ffffff
 
+#define MPIDR_LEVEL_BITS_SHIFT 3
+#define MPIDR_LEVEL_BITS       (1 << MPIDR_LEVEL_BITS_SHIFT)
+#define MPIDR_LEVEL_MASK       ((1 << MPIDR_LEVEL_BITS) - 1)
+
+#define MPIDR_LEVEL_SHIFT(level) \
+       (((1 << level) >> 1) << MPIDR_LEVEL_BITS_SHIFT)
+
+#define MPIDR_AFFINITY_LEVEL(mpidr, level) \
+       ((mpidr >> MPIDR_LEVEL_SHIFT(level)) & MPIDR_LEVEL_MASK)
+
 #define read_cpuid(reg) ({                                             \
        u64 __val;                                                      \
        asm("mrs        %0, " reg : "=r" (__val));                      \