Unmask SError interrupt and clear SCR_EL3.EA bit
This patch disables routing of external aborts from lower exception levels to
EL3 and ensures that a SError interrupt generated as a result of execution in
EL3 is taken locally instead of a lower exception level.
The SError interrupt is enabled in the TSP code only when the operation has not
been directly initiated by the normal world. This is to prevent the possibility
of an asynchronous external abort which originated in normal world from being
taken when execution is in S-EL1.
Fixes ARM-software/tf-issues#153
Change-Id: I157b996c75996d12fd86d27e98bc73dd8bce6cd5
diff --git a/bl31/aarch64/bl31_arch_setup.c b/bl31/aarch64/bl31_arch_setup.c
index f67881e..a88b029 100644
--- a/bl31/aarch64/bl31_arch_setup.c
+++ b/bl31/aarch64/bl31_arch_setup.c
@@ -42,18 +42,8 @@
******************************************************************************/
void bl31_arch_setup(void)
{
- /*
- * Route external abort and SError interrupts to EL3
- * other SCR bits will be configured before exiting to a lower exception
- * level
- */
- write_scr_el3(SCR_RES1_BITS | SCR_EA_BIT);
-
- /*
- * Enable SError and Debug exceptions
- */
- enable_serror();
- enable_debug_exceptions();
+ /* Set the RES1 bits in the SCR_EL3 */
+ write_scr_el3(SCR_RES1_BITS);
/* Program the counter frequency */
write_cntfrq_el0(plat_get_syscnt_freq());
diff --git a/bl31/aarch64/bl31_entrypoint.S b/bl31/aarch64/bl31_entrypoint.S
index c3a09bf..a088c2e 100644
--- a/bl31/aarch64/bl31_entrypoint.S
+++ b/bl31/aarch64/bl31_entrypoint.S
@@ -98,6 +98,14 @@
*/
adr x1, runtime_exceptions
msr vbar_el3, x1
+ isb
+
+ /* ---------------------------------------------
+ * Enable the SError interrupt now that the
+ * exception vectors have been setup.
+ * ---------------------------------------------
+ */
+ msr daifclr, #DAIF_ABT_BIT
/* ---------------------------------------------------------------------
* The initial state of the Architectural feature trap register
diff --git a/bl31/aarch64/runtime_exceptions.S b/bl31/aarch64/runtime_exceptions.S
index 996dedc..f5be9e0 100644
--- a/bl31/aarch64/runtime_exceptions.S
+++ b/bl31/aarch64/runtime_exceptions.S
@@ -44,6 +44,9 @@
* -----------------------------------------------------
*/
.macro handle_sync_exception
+ /* Enable the SError interrupt */
+ msr daifclr, #DAIF_ABT_BIT
+
str x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]
mrs x30, esr_el3
ubfx x30, x30, #ESR_EC_SHIFT, #ESR_EC_LENGTH
@@ -70,6 +73,9 @@
* -----------------------------------------------------
*/
.macro handle_interrupt_exception label
+ /* Enable the SError interrupt */
+ msr daifclr, #DAIF_ABT_BIT
+
str x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]
bl save_gp_registers