Introduce interrupt handling framework in BL3-1
This patch adds a common handler for FIQ and IRQ exceptions in the
BL3-1 runtime exception vector table. This function determines the
interrupt type and calls its handler. A crash is reported if an
inconsistency in the interrupt management framework is detected. In
the event of a spurious interrupt, execution resumes from the
instruction where the interrupt was generated.
This patch also removes 'cm_macros.S' as its contents have been moved
to 'runtime_exceptions.S'
Change-Id: I3c85ecf8eaf43a3fac429b119ed0bd706d2e2093
diff --git a/bl31/aarch64/bl31_entrypoint.S b/bl31/aarch64/bl31_entrypoint.S
index f582e76..3c9042b 100644
--- a/bl31/aarch64/bl31_entrypoint.S
+++ b/bl31/aarch64/bl31_entrypoint.S
@@ -31,8 +31,6 @@
#include <arch.h>
#include <asm_macros.S>
#include <bl_common.h>
-#include <cm_macros.S>
-
.globl bl31_entrypoint
diff --git a/bl31/aarch64/runtime_exceptions.S b/bl31/aarch64/runtime_exceptions.S
index b6dcccb..4789b33 100644
--- a/bl31/aarch64/runtime_exceptions.S
+++ b/bl31/aarch64/runtime_exceptions.S
@@ -30,14 +30,118 @@
#include <arch.h>
#include <asm_macros.S>
-#include <cm_macros.S>
#include <context.h>
+#include <interrupt_mgmt.h>
#include <platform.h>
#include <runtime_svc.h>
.globl runtime_exceptions
.globl el3_exit
+ /* -----------------------------------------------------
+ * Handle SMC exceptions seperately from other sync.
+ * exceptions.
+ * -----------------------------------------------------
+ */
+ .macro handle_sync_exception
+ str x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]
+ mrs x30, esr_el3
+ ubfx x30, x30, #ESR_EC_SHIFT, #ESR_EC_LENGTH
+
+ cmp x30, #EC_AARCH32_SMC
+ b.eq smc_handler32
+
+ cmp x30, #EC_AARCH64_SMC
+ b.eq smc_handler64
+
+ /* -----------------------------------------------------
+ * The following code handles any synchronous exception
+ * that is not an SMC.
+ * -----------------------------------------------------
+ */
+
+ bl dump_state_and_die
+ .endm
+
+
+ /* -----------------------------------------------------
+ * This macro handles FIQ or IRQ interrupts i.e. EL3,
+ * S-EL1 and NS interrupts.
+ * -----------------------------------------------------
+ */
+ .macro handle_interrupt_exception label
+ str x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]
+ bl save_gp_registers
+
+ /* Switch to the runtime stack i.e. SP_EL0 */
+ ldr x2, [sp, #CTX_EL3STATE_OFFSET + CTX_RUNTIME_SP]
+ mov x20, sp
+ msr spsel, #0
+ mov sp, x2
+
+ /*
+ * Find out whether this is a valid interrupt type. If the
+ * interrupt controller reports a spurious interrupt then
+ * return to where we came from.
+ */
+ bl ic_get_pending_interrupt_type
+ cmp x0, #INTR_TYPE_INVAL
+ b.eq interrupt_exit_\label
+
+ /*
+ * Get the registered handler for this interrupt type. A
+ * NULL return value implies that an interrupt was generated
+ * for which there is no handler registered or the interrupt
+ * was routed incorrectly. This is a problem of the framework
+ * so report it as an error.
+ */
+ bl get_interrupt_type_handler
+ cbz x0, interrupt_error_\label
+ mov x21, x0
+
+ mov x0, #INTR_ID_UNAVAILABLE
+#if IMF_READ_INTERRUPT_ID
+ /*
+ * Read the id of the highest priority pending interrupt. If
+ * no interrupt is asserted then return to where we came from.
+ */
+ bl ic_get_pending_interrupt_id
+ cmp x0, #INTR_ID_UNAVAILABLE
+ b.eq interrupt_exit_\label
+#endif
+
+ /*
+ * Save the EL3 system registers needed to return from
+ * this exception.
+ */
+ mrs x3, spsr_el3
+ mrs x4, elr_el3
+ stp x3, x4, [x20, #CTX_EL3STATE_OFFSET + CTX_SPSR_EL3]
+
+ /* Set the current security state in the 'flags' parameter */
+ mrs x2, scr_el3
+ ubfx x1, x2, #0, #1
+
+ /* Restore the reference to the 'handle' i.e. SP_EL3 */
+ mov x2, x20
+
+ /* Call the interrupt type handler */
+ blr x21
+
+interrupt_exit_\label:
+ /* Return from exception, possibly in a different security state */
+ b el3_exit
+
+ /*
+ * This label signifies a problem with the interrupt management
+ * framework where it is not safe to go back to the instruction
+ * where the interrupt was generated.
+ */
+interrupt_error_\label:
+ bl dump_intr_state_and_die
+ .endm
+
+
.macro save_x18_to_x29_sp_el0
stp x18, x19, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X18]
stp x20, x21, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X20]
@@ -140,12 +244,12 @@
* -----------------------------------------------------
*/
irq_aarch64:
- bl dump_intr_state_and_die
+ handle_interrupt_exception irq_aarch64
check_vector_size irq_aarch64
.align 7
fiq_aarch64:
- bl dump_intr_state_and_die
+ handle_interrupt_exception fiq_aarch64
check_vector_size fiq_aarch64
.align 7
@@ -177,12 +281,12 @@
* -----------------------------------------------------
*/
irq_aarch32:
- bl dump_intr_state_and_die
+ handle_interrupt_exception irq_aarch32
check_vector_size irq_aarch32
.align 7
fiq_aarch32:
- bl dump_intr_state_and_die
+ handle_interrupt_exception fiq_aarch32
check_vector_size fiq_aarch32
.align 7
diff --git a/bl31/bl31.mk b/bl31/bl31.mk
index 93a60c7..8155f3d 100644
--- a/bl31/bl31.mk
+++ b/bl31/bl31.mk
@@ -51,3 +51,11 @@
services/std_svc/psci/psci_setup.c
BL31_LINKERFILE := bl31/bl31.ld.S
+
+# Flag used by the generic interrupt management framework to determine if
+# upon the assertion of an interrupt, it should pass the interrupt id or not
+IMF_READ_INTERRUPT_ID := 0
+
+$(eval $(call assert_boolean,IMF_READ_INTERRUPT_ID))
+$(eval $(call add_define,IMF_READ_INTERRUPT_ID))
+