This is a note to let you know that I've just added the patch titled
risc-v: Fix order of IPI enablement vs RCU startup
to the 6.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
risc-v-fix-order-of-ipi-enablement-vs-rcu-startup.patch
and it can be found in the queue-6.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 80241db3373d54810e7bbacc7aea9394850312cc
Author: Marc Zyngier <maz@xxxxxxxxxx>
Date: Mon Jul 3 19:31:26 2023 +0100
risc-v: Fix order of IPI enablement vs RCU startup
[ 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@xxxxxxxxxx>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230703-dupe-frying-79ae2ccf94eb@spud
Cc: Anup Patel <apatel@xxxxxxxxxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Tested-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230703183126.1567625-1-maz@xxxxxxxxxx
Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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);
