arm64: select ARCH_HAS_OPTIMIZED_POLL

poll_idle() uses smp_cond_load*() as its polling mechanism.
arm64 supports an optimized version of this via LDXR, WFE, with
LDXR loading a memory region in exclusive state and the WFE
waiting for any stores to it.

Select ARCH_HAS_OPTIMIZED_POLL so poll_idle() can be used.

Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index fd9df6dcc5937208fe158ac8da9c4ede131d0fc7..43762c68e357a56e23facaf0af92081d5360c64e 100644 (file)
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -38,6 +38,7 @@ config ARM64
        select ARCH_HAS_MEM_ENCRYPT
        select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
        select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
+       select ARCH_HAS_OPTIMIZED_POLL
        select ARCH_HAS_PTE_DEVMAP
        select ARCH_HAS_PTE_SPECIAL
        select ARCH_HAS_HW_PTE_YOUNG