From: Marc Zyngier maz@kernel.org
[ Upstream commit 6259f3443c6a376aa077816ac92e9ddeb0817d09 ]
Conor reports that risc-v tries to enable IPIs before telling the core code to enable RCU. With the introduction of the mapple tree as a backing store for the irq descriptors, this results in a very shouty boot sequence, as RCU is legitimately upset.
Restore some sanity by moving the risc_ipi_enable() call after notify_cpu_starting(), which explicitly enables RCU on the calling CPU.
Fixes: 832f15f42646 ("RISC-V: Treat IPIs as normal Linux IRQs") Reported-by: Conor Dooley conor@kernel.org Signed-off-by: Marc Zyngier maz@kernel.org Link: https://lore.kernel.org/r/20230703-dupe-frying-79ae2ccf94eb@spud Cc: Anup Patel apatel@ventanamicro.com Cc: Palmer Dabbelt palmer@rivosinc.com Cc: Linus Torvalds torvalds@linux-foundation.org Tested-by: Conor Dooley conor.dooley@microchip.com Link: https://lore.kernel.org/r/20230703183126.1567625-1-maz@kernel.org Signed-off-by: Palmer Dabbelt palmer@rivosinc.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/riscv/kernel/smpboot.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c index 445a4efee267d..6765f1ce79625 100644 --- a/arch/riscv/kernel/smpboot.c +++ b/arch/riscv/kernel/smpboot.c @@ -161,10 +161,11 @@ asmlinkage __visible void smp_callin(void) mmgrab(mm); current->active_mm = mm;
- riscv_ipi_enable(); - store_cpu_topology(curr_cpuid); notify_cpu_starting(curr_cpuid); + + riscv_ipi_enable(); + numa_add_cpu(curr_cpuid); set_cpu_online(curr_cpuid, 1); probe_vendor_features(curr_cpuid);