arm64/sme: Fix context switch for SME only systems

When refactoring fpsimd_load() to support keeping SVE enabled over syscalls
support for systems with SME but not SVE was broken. The code that selects
between loading regular FPSIMD and SVE states was guarded by using
system_supports_sve() but is also needed to handle the streaming SVE state
in SME only systems where that check will be false. Fix this by also
checking for system_supports_sme().

Fixes: a0136be443d5 ("arm64/fpsimd: Load FP state based on recorded data type")
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20221223-arm64-fix-sme-only-v1-1-938d663f69e5@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index dcc81e7200d4011c99a448f90853263d321a7e65..b6ef1af0122ebde4984b504e8a14578fe6996ffb 100644 (file)
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -385,7 +385,7 @@ static void task_fpsimd_load(void)
        WARN_ON(!system_supports_fpsimd());
        WARN_ON(!have_cpu_fpsimd_context());
 
-       if (system_supports_sve()) {
+       if (system_supports_sve() || system_supports_sme()) {
                switch (current->thread.fp_type) {
                case FP_STATE_FPSIMD:
                        /* Stop tracking SVE for this task until next use. */