Move context management code to common location

The upcoming Firmware Update feature needs transitioning across
Secure/Normal worlds to complete the FWU process and hence requires
context management code to perform this task.

Currently context management code is part of BL31 stage only.
This patch moves the code from (include)/bl31 to (include)/common.
Some function declarations/definitions and macros have also moved
to different files to help code sharing.

Change-Id: I3858b08aecdb76d390765ab2b099f457873f7b0c

1 files changed, 2 insertions, 82 deletions

diff --git a/bl31/aarch64/runtime_exceptions.S b/bl31/aarch64/runtime_exceptions.S
index 28353202..dc11e0a7 100644
--- a/bl31/aarch64/runtime_exceptions.S
+++ b/bl31/aarch64/runtime_exceptions.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2015, ARM Limited and Contributors. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -36,7 +36,6 @@
 #include <runtime_svc.h>
 
 	.globl	runtime_exceptions
-	.globl	el3_exit
 
 	/* -----------------------------------------------------
 	 * Handle SMC exceptions separately from other sync.
@@ -426,38 +425,7 @@ smc_handler64:
 #endif
 	blr	x15
 
-	/* -----------------------------------------------------
-	 * This routine assumes that the SP_EL3 is pointing to
-	 * a valid context structure from where the gp regs and
-	 * other special registers can be retrieved.
-	 *
-	 * Keep it in the same section as smc_handler as this
-	 * function uses a fall-through to el3_exit
-	 * -----------------------------------------------------
-	 */
-el3_exit: ; .type el3_exit, %function
-	/* -----------------------------------------------------
-	 * Save the current SP_EL0 i.e. the EL3 runtime stack
-	 * which will be used for handling the next SMC. Then
-	 * switch to SP_EL3
-	 * -----------------------------------------------------
-	 */
-	mov	x17, sp
-	msr	spsel, #1
-	str	x17, [sp, #CTX_EL3STATE_OFFSET + CTX_RUNTIME_SP]
-
-	/* -----------------------------------------------------
-	 * Restore SPSR_EL3, ELR_EL3 and SCR_EL3 prior to ERET
-	 * -----------------------------------------------------
-	 */
-	ldr	x18, [sp, #CTX_EL3STATE_OFFSET + CTX_SCR_EL3]
-	ldp	x16, x17, [sp, #CTX_EL3STATE_OFFSET + CTX_SPSR_EL3]
-	msr	scr_el3, x18
-	msr	spsr_el3, x16
-	msr	elr_el3, x17
-
-	/* Restore saved general purpose registers and return */
-	b	restore_gp_registers_eret
+	b	el3_exit
 
 smc_unknown:
 	/*
@@ -479,51 +447,3 @@ rt_svc_fw_critical_error:
 	msr	spsel, #1 /* Switch to SP_ELx */
 	bl	report_unhandled_exception
 endfunc smc_handler
-
-	/* -----------------------------------------------------
-	 * The following functions are used to saved and restore
-	 * all the general pupose registers. Ideally we would
-	 * only save and restore the callee saved registers when
-	 * a world switch occurs but that type of implementation
-	 * is more complex. So currently we will always save and
-	 * restore these registers on entry and exit of EL3.
-	 * These are not macros to ensure their invocation fits
-	 * within the 32 instructions per exception vector.
-	 * -----------------------------------------------------
-	 */
-func save_gp_registers
-	stp	x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0]
-	stp	x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2]
-	stp	x4, x5, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X4]
-	stp	x6, x7, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X6]
-	stp	x8, x9, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X8]
-	stp	x10, x11, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X10]
-	stp	x12, x13, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X12]
-	stp	x14, x15, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X14]
-	stp	x16, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X16]
-	save_x18_to_x29_sp_el0
-	ret
-endfunc save_gp_registers
-
-func restore_gp_registers_eret
-	ldp	x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0]
-	ldp	x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2]
-
-restore_gp_registers_callee_eret:
-	ldp	x4, x5, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X4]
-	ldp	x6, x7, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X6]
-	ldp	x8, x9, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X8]
-	ldp	x10, x11, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X10]
-	ldp	x12, x13, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X12]
-	ldp	x14, x15, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X14]
-	ldp	x18, x19, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X18]
-	ldp	x20, x21, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X20]
-	ldp	x22, x23, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X22]
-	ldp	x24, x25, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X24]
-	ldp	x26, x27, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X26]
-	ldp	x28, x29, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X28]
-	ldp	x30, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]
-	msr	sp_el0, x17
-	ldp	x16, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X16]
-	eret
-endfunc restore_gp_registers_eret