fix(bl31): allow use of EHF with S-EL2 SPMC
Currently, when SPMC at S-EL2 is used, we cannot use the RAS framework
to handle Group 0 interrupts. This is required on platforms where first
level of triaging needs to occur at EL3, before forwarding RAS handling
to a secure partition running atop an SPMC (hafnium).
The RAS framework depends on EHF and EHF registers for Group 0
interrupts to be trapped to EL3 when execution is both in secure world
and normal world. However, an FF-A compliant SPMC requires secure
interrupts to be trapped by the SPMC when execution is in S-EL0/S-EL1.
Consequently, the SPMC (hafnium) is incompatible with EHF, since it is
not re-entrant, and a Group 0 interrupt trapped to EL3 when execution is
in secure world, cannot be forwarded to an SP running atop SPMC.
This patch changes EHF to only register for Group 0 interrupts to be
trapped to EL3 when execution is in normal world and also makes it a
valid routing model to do so, when EL3_EXCEPTION_HANDLING is set (when
enabling the RAS framework).
Signed-off-by: Raghu Krishnamurthy <raghu.ncstate@gmail.com>
Change-Id: I72d4cf4d8ecc549a832d1c36055fbe95866747fe
diff --git a/bl31/ehf.c b/bl31/ehf.c
index 745f165..b328380 100644
--- a/bl31/ehf.c
+++ b/bl31/ehf.c
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2022, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -475,9 +475,16 @@
assert((exception_data.pri_bits >= 1U) ||
(exception_data.pri_bits < 8U));
- /* Route EL3 interrupts when in Secure and Non-secure. */
+ /* Route EL3 interrupts when in Non-secure. */
set_interrupt_rm_flag(flags, NON_SECURE);
+
+ /*
+ * Route EL3 interrupts when in secure, only when SPMC is not present
+ * in S-EL2.
+ */
+#if !(defined(SPD_spmd) && (SPMD_SPM_AT_SEL2 == 1))
set_interrupt_rm_flag(flags, SECURE);
+#endif /* !(defined(SPD_spmd) && (SPMD_SPM_AT_SEL2 == 1)) */
/* Register handler for EL3 interrupts */
ret = register_interrupt_type_handler(INTR_TYPE_EL3,