diff options
Diffstat (limited to 'arch/arm64/include/asm/cache.h')
| -rw-r--r-- | arch/arm64/include/asm/cache.h | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/cache.h b/arch/arm64/include/asm/cache.h index 99cd6546e72e..09963004ceea 100644 --- a/arch/arm64/include/asm/cache.h +++ b/arch/arm64/include/asm/cache.h @@ -87,6 +87,23 @@ int cache_line_size(void); #define dma_get_cache_alignment cache_line_size +/* Compress a u64 MPIDR value into 32 bits. */ +static inline u64 arch_compact_of_hwid(u64 id) +{ + u64 aff3 = MPIDR_AFFINITY_LEVEL(id, 3); + + /* + * These bits are expected to be RES0. If not, return a value with + * the upper 32 bits set to force the caller to give up on 32 bit + * cache ids. + */ + if (FIELD_GET(GENMASK_ULL(63, 40), id)) + return id; + + return (aff3 << 24) | FIELD_GET(GENMASK_ULL(23, 0), id); +} +#define arch_compact_of_hwid arch_compact_of_hwid + /* * Read the effective value of CTR_EL0. * |