[PATCH V1 5/6] arm64: exception: handle instruction abort at current EL

From: Tyler Baicar
Date: Fri Feb 05 2016 - 14:15:01 EST


Add a handler for instruction aborts at the current EL
(ESR_ELx_EC_IABT_CUR) so they are no longer handled in el1_inv.
This allows firmware first handling for possible SEA
(Synchronous External Abort) caused instruction abort at
current EL.

Signed-off-by: Tyler Baicar <tbaicar@xxxxxxxxxxxxxx>
Signed-off-by: Naveen Kaje <nkaje@xxxxxxxxxxxxxx>
---
arch/arm64/kernel/entry.S | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 1f7f5a2..6b7fb14 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -336,6 +336,8 @@ el1_sync:
lsr x24, x1, #ESR_ELx_EC_SHIFT // exception class
cmp x24, #ESR_ELx_EC_DABT_CUR // data abort in EL1
b.eq el1_da
+ cmp x24, #ESR_ELx_EC_IABT_CUR // instruction abort in EL1
+ b.eq el1_ia
cmp x24, #ESR_ELx_EC_SYS64 // configurable trap
b.eq el1_undef
cmp x24, #ESR_ELx_EC_SP_ALIGN // stack alignment exception
@@ -363,6 +365,23 @@ el1_da:
// disable interrupts before pulling preserved data off the stack
disable_irq
kernel_exit 1
+el1_ia:
+ /*
+ * Instruction abort handling
+ */
+ mrs x0, far_el1
+ enable_dbg
+ // re-enable interrupts if they were enabled in the aborted context
+ tbnz x23, #7, 1f // PSR_I_BIT
+ enable_irq
+1:
+ orr x1, x1, #1 << 24 // use reserved ISS bit for instruction aborts
+ mov x2, sp // struct pt_regs
+ bl do_mem_abort
+
+ // disable interrupts before pulling preserved data off the stack
+ disable_irq
+ kernel_exit 1
el1_sp_pc:
/*
* Stack or PC alignment exception handling
--
1.8.2.1