[PATCH AUTOSEL 6.6 29/35] arm64: armv8_deprecated: Fix warning in isndep cpuhp starting process

Sasha Levin
2024-06-17T13:24:20Z

From: Wei Li <liwei391@huawei.com>

[ Upstream commit 14951beaec93696b092a906baa0f29322cf34004 ]

The function run_all_insn_set_hw_mode() is registered as startup callback
of 'CPUHP_AP_ARM64_ISNDEP_STARTING', it invokes set_hw_mode() methods of
all emulated instructions.

As the STARTING callbacks are not expected to fail, if one of the
set_hw_mode() fails, e.g. due to el0 mixed-endian is not supported for
'setend', it will report a warning:

```
CPU[2] cannot support the emulation of setend
CPU 2 UP state arm64/isndep:starting (136) failed (-22)
CPU2: Booted secondary processor 0x0000000002 [0x414fd0c1]
```

To fix it, add a check for INSN_UNAVAILABLE status and skip the process.

Signed-off-by: Wei Li <liwei391@huawei.com>
Tested-by: Huisong Li <lihuisong@huawei.com>
Link: https://lore.kernel.org/r/20240423093501.3460764-1-liwei391@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/arm64/kernel/armv8_deprecated.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c
index e459cfd337117..d6b711e56df97 100644
--- a/arch/arm64/kernel/armv8_deprecated.c
+++ b/arch/arm64/kernel/armv8_deprecated.c
@@ -464,6 +464,9 @@ static int run_all_insn_set_hw_mode(unsigned int cpu)
for (int i = 0; i < ARRAY_SIZE(insn_emulations); i++) {
struct insn_emulation *insn = insn_emulations[i];
bool enable = READ_ONCE(insn->current_mode) == INSN_HW;
+ if (insn->status == INSN_UNAVAILABLE)
+ continue;
+
if (insn->set_hw_mode && insn->set_hw_mode(enable)) {
pr_warn("CPU[%u] cannot support the emulation of %s",
cpu, insn->name);
--
2.43.0