From cc64bfee92c8e9de7de041dec613956522c16f4c Mon Sep 17 00:00:00 2001 From: Samuel Holland Date: Tue, 26 Mar 2024 21:49:42 -0700 Subject: [PATCH] riscv: Flush the instruction cache during SMP bringup BugLink: https://bugs.launchpad.net/bugs/2073603 [ Upstream commit 58661a30f1bcc748475ffd9be6d2fc9e4e6be679 ] Instruction cache flush IPIs are sent only to CPUs in cpu_online_mask, so they will not target a CPU until it calls set_cpu_online() earlier in smp_callin(). As a result, if instruction memory is modified between the CPU coming out of reset and that point, then its instruction cache may contain stale data. Therefore, the instruction cache must be flushed after the set_cpu_online() synchronization point. Fixes: 08f051eda33b ("RISC-V: Flush I$ when making a dirty page executable") Reviewed-by: Alexandre Ghiti Signed-off-by: Samuel Holland Link: https://lore.kernel.org/r/20240327045035.368512-2-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt Signed-off-by: Sasha Levin Signed-off-by: Portia Stephens Signed-off-by: Roxana Nicolescu --- arch/riscv/kernel/smpboot.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c index 519b6bd946e5..bbdb9ec62df0 100644 --- a/arch/riscv/kernel/smpboot.c +++ b/arch/riscv/kernel/smpboot.c @@ -26,7 +26,7 @@ #include #include -#include +#include #include #include #include @@ -239,9 +239,10 @@ asmlinkage __visible void smp_callin(void) riscv_user_isa_enable(); /* - * Remote TLB flushes are ignored while the CPU is offline, so emit - * a local TLB flush right now just in case. + * Remote cache and TLB flushes are ignored while the CPU is offline, + * so flush them both right now just in case. */ + local_flush_icache_all(); local_flush_tlb_all(); complete(&cpu_running); /*