arm64: Make exceptions use the transition library

Transition library acts as a common interface for handling exceptions. The only
thing that needs to be implemented by exception.c is the exc_dispatch routine to
handle the exceptions as required.

BUG=chrome-os-partner:30785
BRANCH=None
TEST=Compiles successfully and exceptions are tested using test_exc

Change-Id: I90b4861909189adfe8449b9d4590965e6b743c00
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: b83c9404407dd4dd2dda4e4eaed0b443f0f58425
Original-Change-Id: Ibb643d7ea2f9aabbc66439549ea2168fd66ced5e
Original-Signed-off-by: Furquan Shaikh <furquan@google.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/217143
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Original-Tested-by: Furquan Shaikh <furquan@chromium.org>
Original-Commit-Queue: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: http://review.coreboot.org/9071
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

3 files changed, 24 insertions, 146 deletions

diff --git a/src/arch/arm64/armv8/Makefile.inc b/src/arch/arm64/armv8/Makefile.inc
index 61e37e68ae..52663b85c5 100644
--- a/src/arch/arm64/armv8/Makefile.inc
+++ b/src/arch/arm64/armv8/Makefile.inc
@@ -38,7 +38,6 @@ bootblock-$(CONFIG_ARM_BOOTBLOCK_NORMAL) += bootblock_normal.c
 bootblock-y += cache.c
 bootblock-y += cpu.S
 bootblock-$(CONFIG_BOOTBLOCK_CONSOLE) += exception.c
-bootblock-$(CONFIG_BOOTBLOCK_CONSOLE) += exception_asm.S
 
 bootblock-c-ccopts += $(armv8_flags)
 bootblock-S-ccopts += $(armv8_asm_flags)
@@ -53,7 +52,6 @@ ifeq ($(CONFIG_ARCH_ROMSTAGE_ARMV8_64),y)
 romstage-y += cache.c
 romstage-y += cpu.S
 romstage-y += exception.c
-romstage-y += exception_asm.S
 
 romstage-c-ccopts += $(armv8_flags)
 romstage-S-ccopts += $(armv8_asm_flags)
@@ -71,7 +69,6 @@ ifeq ($(CONFIG_ARCH_RAMSTAGE_ARMV8_64),y)
 ramstage-y += cache.c
 ramstage-y += cpu.S
 ramstage-y += exception.c
-ramstage-y += exception_asm.S
 ramstage-y += mmu.c
 
 ramstage-c-ccopts += $(armv8_flags)
diff --git a/src/arch/arm64/armv8/exception.c b/src/arch/arm64/armv8/exception.c
index d9a63c3a81..0aef0e5457 100644
--- a/src/arch/arm64/armv8/exception.c
+++ b/src/arch/arm64/armv8/exception.c
@@ -31,6 +31,7 @@
 #include <types.h>
 #include <arch/cache.h>
 #include <arch/exception.h>
+#include <arch/transition.h>
 #include <console/console.h>
 #include <arch/lib_helpers.h>
 
@@ -80,24 +81,28 @@ static struct exception_handler_info exceptions[EXC_COUNT] = {
 	[EXC_SERROR_ELX_32] = {"_serror_elx_32"},
 };
 
-static void print_regs(struct exception_state *state)
+static void print_regs(struct exc_state *exc_state)
 {
 	int i;
-	uint64_t far_el3;
-
-	far_el3 = raw_read_far_el3();
-
-	printk(BIOS_DEBUG, "ELR = 0x%016llx\n", state->elr);
-	printk(BIOS_DEBUG, "ESR = 0x%08llx\n", state->esr);
-	printk(BIOS_DEBUG, "FAR_EL3 = 0x%016llx\n", far_el3);
-	for (i = 0; i < 31; i++)
-		printk(BIOS_DEBUG, "X%02d = 0x%016llx\n", i, state->regs[i]);
+	struct elx_state *elx = &exc_state->elx;
+	struct regs *regs = &exc_state->regs;
+
+	uint64_t elx_esr = raw_read_esr_current();
+	uint64_t elx_far = raw_read_far_current();
+
+	printk(BIOS_DEBUG, "ELR = 0x%016llx\n", elx->elr);
+	printk(BIOS_DEBUG, "ESR = 0x%016llx\n", elx_esr);
+	printk(BIOS_DEBUG, "SPSR = 0x%08llx\n", elx->spsr);
+	printk(BIOS_DEBUG, "FAR = 0x%016llx\n", elx_far);
+	for (i = X0_INDEX; i < XMAX_INDEX; i++)
+		printk(BIOS_DEBUG, "X%02d = 0x%016llx\n", i, regs->x[i]);
 }
 
-void exception_dispatch(struct exception_state *state, int idx)
+void exc_dispatch(struct exc_state *exc_state, uint64_t idx)
 {
 	if (idx >= EXC_COUNT) {
-		printk(BIOS_DEBUG, "Bad exception index %d.\n", idx);
+		printk(BIOS_DEBUG, "Bad exception index %lx.\n",
+		       (unsigned long)idx);
 	} else {
 		struct exception_handler_info *info = &exceptions[idx];
 
@@ -106,14 +111,17 @@ void exception_dispatch(struct exception_state *state, int idx)
 		else
 			printk(BIOS_DEBUG, "exception _not_used.\n");
 	}
-	print_regs(state);
+	print_regs(exc_state);
 
 	if (test_exc) {
-		state->elr += 4;
+		exc_state->elx.elr += 4;
+		raw_write_elr_current(exc_state->elx.elr);
 		test_exc = 0;
-		printk(BIOS_DEBUG, "new ELR = 0x%016llx\n", state->elr);
+		printk(BIOS_DEBUG, "new ELR = 0x%016llx\n", exc_state->elx.elr);
 	} else
 		die("exception");
+
+	exc_exit(&exc_state->regs);
 }
 
 static uint64_t test_exception(void)
@@ -129,8 +137,7 @@ static uint64_t test_exception(void)
 
 void exception_hwinit(void)
 {
-	extern void *exception_table;
-	set_vbar(&exception_table);
+	exc_set_vbar();
 }
 
 void exception_init(void)
diff --git a/src/arch/arm64/armv8/exception_asm.S b/src/arch/arm64/armv8/exception_asm.S
deleted file mode 100644
index 66377235cd..0000000000
--- a/src/arch/arm64/armv8/exception_asm.S
+++ /dev/null
@@ -1,126 +0,0 @@
-/*
- * This file is part of the libpayload project.
- *
- * Copyright 2014 Google Inc.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- * 3. The name of the author may not be used to endorse or promote products
- *    derived from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-#include <arch/asm.h>
-
-.macro eentry lbl id
-	.align 7
-\lbl:
-	stp	x30, xzr, [sp, #-16]!
-	bl	exception_prologue
-	mov	x1, \id
-	bl	exception_handler
-.endm
-
-	.align	11
-	.global exception_table
-
-exception_table:
-
-eentry	sync_el3_sp0,#0
-eentry	irq_el3_sp0,#1
-eentry	fiq_el3_sp0,#2
-eentry	serror_el3_sp0,#3
-eentry	sync_el3_sp3,#4
-eentry	irq_el3_sp3,#5
-eentry	fiq_el3_sp3,#6
-eentry	serror_el3_sp3,#7
-eentry	sync_elx_64,#8
-eentry	irq_elx_64,#9
-eentry	fiq_elx_64,#10
-eentry	serror_elx_64,#11
-eentry	sync_elx_32,#12
-eentry	irq_elx_32,#13
-eentry	fiq_elx_32,#14
-eentry	serror_elx_32,#15
-
-exception_prologue:
-	/* Save all registers x0-x29 */
-	stp	x28, x29, [sp, #-16]!
-	stp	x26, x27, [sp, #-16]!
-	stp	x24, x25, [sp, #-16]!
-	stp	x22, x23, [sp, #-16]!
-	stp	x20, x21, [sp, #-16]!
-	stp	x18, x19, [sp, #-16]!
-	stp	x16, x17, [sp, #-16]!
-	stp	x14, x15, [sp, #-16]!
-	stp	x12, x13, [sp, #-16]!
-	stp	x10, x11, [sp, #-16]!
-	stp	x8, x9, [sp, #-16]!
-	stp	x6, x7, [sp, #-16]!
-	stp	x4, x5, [sp, #-16]!
-	stp	x2, x3, [sp, #-16]!
-	stp	x0, x1, [sp, #-16]!
-
-	/* Save the exception reason on stack */
-	mrs	x1,  esr_el3
-
-	/* Save the return address on stack */
-	mrs	x0, elr_el3
-	stp	x0, x1, [sp, #-16]!
-
-	ret
-
-exception_handler:
-	/* Save address of saved registers into x0
-	 * This acts as first argument to exception_dispatch
-	 */
-	mov	x0, sp
-	bl	exception_dispatch
-
-	/* Pop return address and exception reason saved on stack */
-	ldp	x0, x1, [sp], #16
-	msr	elr_el3, x0
-	msr	esr_el3, x1
-	/* Pop registers x0-x30 */
-	ldp	x0, x1, [sp], #16
-	ldp	x2, x3, [sp], #16
-	ldp	x4, x5, [sp], #16
-	ldp	x6, x7, [sp], #16
-	ldp	x8, x9, [sp], #16
-	ldp	x10, x11, [sp], #16
-	ldp	x12, x13, [sp], #16
-	ldp	x14, x15, [sp], #16
-	ldp	x16, x17, [sp], #16
-	ldp	x18, x19, [sp], #16
-	ldp	x20, x21, [sp], #16
-	ldp	x22, x23, [sp], #16
-	ldp	x24, x25, [sp], #16
-	ldp	x26, x27, [sp], #16
-	ldp	x28, x29, [sp], #16
-	ldp	x30, xzr, [sp], #16
-	eret
-
-	.global set_vbar
-set_vbar:
-	/* Initialize the exception table address in vbar for EL3 */
-	msr	vbar_el3, x0
-	dsb	sy
-	isb
-	ret