From 0c8d4fef28768233f1f46b4d085f904293dffd2c Mon Sep 17 00:00:00 2001 From: Achin Gupta Date: Mon, 4 Aug 2014 23:13:10 +0100 Subject: [PATCH] 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 --- bl1/aarch64/bl1_arch_setup.c | 13 ++----------- bl1/aarch64/bl1_entrypoint.S | 8 ++++++++ bl1/aarch64/bl1_exceptions.S | 3 +++ bl2/aarch64/bl2_entrypoint.S | 8 ++++++++ bl31/aarch64/bl31_arch_setup.c | 14 ++------------ bl31/aarch64/bl31_entrypoint.S | 8 ++++++++ bl31/aarch64/runtime_exceptions.S | 6 ++++++ bl32/tsp/aarch64/tsp_entrypoint.S | 12 ++++++++++++ bl32/tsp/aarch64/tsp_exceptions.S | 6 ++++++ services/std_svc/psci/psci_entry.S | 7 +++++++ 10 files changed, 62 insertions(+), 23 deletions(-) diff --git a/bl1/aarch64/bl1_arch_setup.c b/bl1/aarch64/bl1_arch_setup.c index eeaa24aff..6a3f06231 100644 --- a/bl1/aarch64/bl1_arch_setup.c +++ b/bl1/aarch64/bl1_arch_setup.c @@ -37,17 +37,8 @@ ******************************************************************************/ void bl1_arch_setup(void) { - /* - * Set the next EL to be AArch64, route external abort and SError - * interrupts to EL3 - */ - write_scr_el3(SCR_RES1_BITS | SCR_RW_BIT | SCR_EA_BIT); - - /* - * Enable SError and Debug exceptions - */ - enable_serror(); - enable_debug_exceptions(); + /* Set the next EL to be AArch64 */ + write_scr_el3(SCR_RES1_BITS | SCR_RW_BIT); } /******************************************************************************* diff --git a/bl1/aarch64/bl1_entrypoint.S b/bl1/aarch64/bl1_entrypoint.S index dd7d78feb..e7f92c71d 100644 --- a/bl1/aarch64/bl1_entrypoint.S +++ b/bl1/aarch64/bl1_entrypoint.S @@ -76,6 +76,14 @@ func bl1_entrypoint */ adr x0, bl1_exceptions msr vbar_el3, x0 + 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/bl1/aarch64/bl1_exceptions.S b/bl1/aarch64/bl1_exceptions.S index 8ab9df861..13b34b79f 100644 --- a/bl1/aarch64/bl1_exceptions.S +++ b/bl1/aarch64/bl1_exceptions.S @@ -112,6 +112,9 @@ SErrorSPx: */ .align 7 SynchronousExceptionA64: + /* Enable the SError interrupt */ + msr daifclr, #DAIF_ABT_BIT + /* ------------------------------------------------ * Only a single SMC exception from BL2 to ask * BL1 to pass EL3 control to BL31 is expected diff --git a/bl2/aarch64/bl2_entrypoint.S b/bl2/aarch64/bl2_entrypoint.S index d3b0f558c..2f058da9f 100644 --- a/bl2/aarch64/bl2_entrypoint.S +++ b/bl2/aarch64/bl2_entrypoint.S @@ -53,6 +53,14 @@ func bl2_entrypoint */ adr x0, early_exceptions msr vbar_el1, x0 + isb + + /* --------------------------------------------- + * Enable the SError interrupt now that the + * exception vectors have been setup. + * --------------------------------------------- + */ + msr daifclr, #DAIF_ABT_BIT /* --------------------------------------------- * Enable the instruction cache, stack pointer diff --git a/bl31/aarch64/bl31_arch_setup.c b/bl31/aarch64/bl31_arch_setup.c index f67881e6b..a88b029ea 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 c3a09bf33..a088c2e03 100644 --- a/bl31/aarch64/bl31_entrypoint.S +++ b/bl31/aarch64/bl31_entrypoint.S @@ -98,6 +98,14 @@ func bl31_entrypoint */ 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 996dedcb5..f5be9e077 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 diff --git a/bl32/tsp/aarch64/tsp_entrypoint.S b/bl32/tsp/aarch64/tsp_entrypoint.S index 75ee44349..002c41b81 100644 --- a/bl32/tsp/aarch64/tsp_entrypoint.S +++ b/bl32/tsp/aarch64/tsp_entrypoint.S @@ -77,6 +77,14 @@ func tsp_entrypoint */ adr x0, tsp_exceptions msr vbar_el1, x0 + isb + + /* --------------------------------------------- + * Enable the SError interrupt now that the + * exception vectors have been setup. + * --------------------------------------------- + */ + msr daifclr, #DAIF_ABT_BIT /* --------------------------------------------- * Enable the instruction cache, stack pointer @@ -186,6 +194,10 @@ func tsp_cpu_on_entry */ adr x0, tsp_exceptions msr vbar_el1, x0 + isb + + /* Enable the SError interrupt */ + msr daifclr, #DAIF_ABT_BIT /* --------------------------------------------- * Enable the instruction cache, stack pointer diff --git a/bl32/tsp/aarch64/tsp_exceptions.S b/bl32/tsp/aarch64/tsp_exceptions.S index f84b5e099..4c0d4361e 100644 --- a/bl32/tsp/aarch64/tsp_exceptions.S +++ b/bl32/tsp/aarch64/tsp_exceptions.S @@ -120,6 +120,9 @@ sync_exception_sp_elx: .align 7 irq_sp_elx: + /* Enable the SError interrupt */ + msr daifclr, #DAIF_ABT_BIT + save_caller_regs_and_lr /* We just update some statistics in the handler */ bl tsp_irq_received @@ -132,6 +135,9 @@ irq_sp_elx: .align 7 fiq_sp_elx: + /* Enable the SError interrupt */ + msr daifclr, #DAIF_ABT_BIT + save_caller_regs_and_lr bl tsp_fiq_handler cbz x0, fiq_sp_elx_done diff --git a/services/std_svc/psci/psci_entry.S b/services/std_svc/psci/psci_entry.S index e9ad1305b..68b917e39 100644 --- a/services/std_svc/psci/psci_entry.S +++ b/services/std_svc/psci/psci_entry.S @@ -87,6 +87,13 @@ psci_aff_common_finish_entry: msr vbar_el3, x0 isb + /* --------------------------------------------- + * Enable the SError interrupt now that the + * exception vectors have been setup. + * --------------------------------------------- + */ + msr daifclr, #DAIF_ABT_BIT + /* --------------------------------------------- * Use SP_EL0 for the C runtime stack. * ---------------------------------------------