[PATCH 5.15 028/245] MIPS: reserve exception vector space ONLY ONCE

Greg Kroah-Hartman
2024-02-27T14:02:28Z

From: Huang Pei <huangpei@loongson.cn>

[ Upstream commit abcabb9e30a1f9a69c76776f8abffc31c377b542 ]

"cpu_probe" is called both by BP and APs, but reserving exception vector
(like 0x0-0x1000) called by "cpu_probe" need once and calling on APs is
too late since memblock is unavailable at that time.

So, reserve exception vector ONLY by BP.

Suggested-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Huang Pei <huangpei@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/mips/kernel/traps.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index afb2c955d99ef..5c01a21a216b9 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -2001,7 +2001,13 @@ unsigned long vi_handlers[64];

void reserve_exception_space(phys_addr_t addr, unsigned long size)
{
- memblock_reserve(addr, size);
+ /*
+ * reserve exception space on CPUs other than CPU0
+ * is too late, since memblock is unavailable when APs
+ * up
+ */
+ if (smp_processor_id() == 0)
+ memblock_reserve(addr, size);
}

void __init *set_except_vector(int n, void *addr)
--
2.43.0