diff mbox series

[v4,03/27] arm64/fpsimd: Check enable bit for FA64 when saving EFI state

Message ID 20250214-kvm-arm64-sme-v4-3-d64a681adcc2@kernel.org
State New
Headers show
Series [v4,01/27] arm64/fpsimd: Update FA64 and ZT0 enables when loading SME state | expand

Commit Message

Mark Brown Feb. 14, 2025, 1:57 a.m. UTC 
Currently when deciding if we need to save FFR when in streaming mode prior
to EFI calls we check if FA64 is supported by the system. Since KVM guest
support will mean that FA64 might be enabled and disabled at runtime switch
to checking if traps for FA64 are enabled in SMCR_EL1 instead.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 arch/arm64/kernel/fpsimd.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index 446a379d87539bb37a9d4eb7466a73d8819afc56..a97af9daea472cc57bafc0564fdfe4e327924db1 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -1955,6 +1955,11 @@  static DEFINE_PER_CPU(bool, efi_sm_state);
  * either doing something wrong or you need to propose some refactoring.
  */
 
+static bool fa64_enabled(void)
+{
+	return read_sysreg_s(SYS_SMCR_EL1) & SMCR_ELx_FA64;
+}
+
 /*
  * __efi_fpsimd_begin(): prepare FPSIMD for making an EFI runtime services call
  */
@@ -1989,7 +1994,7 @@  void __efi_fpsimd_begin(void)
 				 * Unless we have FA64 FFR does not
 				 * exist in streaming mode.
 				 */
-				if (!system_supports_fa64())
+				if (!fa64_enabled())
 					ffr = !(svcr & SVCR_SM_MASK);
 			}
 
@@ -2040,7 +2045,7 @@  void __efi_fpsimd_end(void)
 					 * Unless we have FA64 FFR does not
 					 * exist in streaming mode.
 					 */
-					if (!system_supports_fa64())
+					if (!fa64_enabled())
 						ffr = false;
 				}
 			}