[PATCH AUTOSEL 5.15 18/21] arm64: armv8_deprecated: Fix warning in isndep cpuhp starting process

[Sasha Levin]

From: Wei Li <liwei391 at 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 at huawei.com>
Tested-by: Huisong Li <lihuisong at huawei.com>
Link: https://lore.kernel.org/r/20240423093501.3460764-1-liwei391@huawei.com
Signed-off-by: Will Deacon <will at kernel.org>
Signed-off-by: Sasha Levin <sashal at 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 91eabe56093d6..91c29979aea79 100644
--- a/arch/arm64/kernel/armv8_deprecated.c
+++ b/arch/arm64/kernel/armv8_deprecated.c
@@ -471,6 +471,9 @@ static int run_all_insn_set_hw_mode(unsigned int cpu)
 	for (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