riscv: Allow to enable PREEMPT_RT.

It is really time.

riscv has all the required architecture related changes, that have been
identified over time, in order to enable PREEMPT_RT. With the recent
printk changes, the last known road block has been addressed.

Allow to enable PREEMPT_RT on riscv.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Nam Cao <namcao@linutronix.de> # Visionfive 2
Link: https://lore.kernel.org/all/20240906111841.562402-4-bigeasy@linutronix.de

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 86d1f1cea571667215ed42e4b2e31215f775043e..82724bc95b7459b586dc7cc4adc42459ef553b4a 100644 (file)
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -65,6 +65,7 @@ config RISCV
        select ARCH_SUPPORTS_LTO_CLANG_THIN if LLD_VERSION >= 140000
        select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU
        select ARCH_SUPPORTS_PER_VMA_LOCK if MMU
+       select ARCH_SUPPORTS_RT
        select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK
        select ARCH_USE_CMPXCHG_LOCKREF if 64BIT
        select ARCH_USE_MEMTEST