[PATCH kvm-unit-tests 1/8] arm/arm64: Reorganize cstart assembler

[Andrew Jones <drjones@redhat.com>]

Move secondary_entry helper functions out of .init and into .text,
since secondary_entry isn't run at "init" time.

Signed-off-by: Andrew Jones <drjones@redhat.com>
---
 arm/cstart.S   | 62 +++++++++++++++++++++++++++-----------------------
 arm/cstart64.S | 22 +++++++++++-------
 2 files changed, 48 insertions(+), 36 deletions(-)

diff --git a/arm/cstart.S b/arm/cstart.S
index d88a98362940..653ab1e8a141 100644
--- a/arm/cstart.S
+++ b/arm/cstart.S
@@ -96,32 +96,7 @@ start:
 	bl	exit
 	b	halt
 
-
-.macro set_mode_stack mode, stack
-	add	\stack, #S_FRAME_SIZE
-	msr	cpsr_c, #(\mode | PSR_I_BIT | PSR_F_BIT)
-	isb
-	mov	sp, \stack
-.endm
-
-exceptions_init:
-	mrc	p15, 0, r2, c1, c0, 0	@ read SCTLR
-	bic	r2, #CR_V		@ SCTLR.V := 0
-	mcr	p15, 0, r2, c1, c0, 0	@ write SCTLR
-	ldr	r2, =vector_table
-	mcr	p15, 0, r2, c12, c0, 0	@ write VBAR
-
-	mrs	r2, cpsr
-
-	/* first frame reserved for svc mode */
-	set_mode_stack	UND_MODE, r0
-	set_mode_stack	ABT_MODE, r0
-	set_mode_stack	IRQ_MODE, r0
-	set_mode_stack	FIQ_MODE, r0
-
-	msr	cpsr_cxsf, r2		@ back to svc mode
-	isb
-	mov	pc, lr
+.text
 
 enable_vfp:
 	/* Enable full access to CP10 and CP11: */
@@ -133,8 +108,6 @@ enable_vfp:
 	vmsr	fpexc, r0
 	mov	pc, lr
 
-.text
-
 .global get_mmu_off
 get_mmu_off:
 	ldr	r0, =auxinfo
@@ -235,6 +208,39 @@ asm_mmu_disable:
 
 	mov     pc, lr
 
+/*
+ * Vectors
+ */
+
+.macro set_mode_stack mode, stack
+	add	\stack, #S_FRAME_SIZE
+	msr	cpsr_c, #(\mode | PSR_I_BIT | PSR_F_BIT)
+	isb
+	mov	sp, \stack
+.endm
+
+exceptions_init:
+	mrc	p15, 0, r2, c1, c0, 0	@ read SCTLR
+	bic	r2, #CR_V		@ SCTLR.V := 0
+	mcr	p15, 0, r2, c1, c0, 0	@ write SCTLR
+	ldr	r2, =vector_table
+	mcr	p15, 0, r2, c12, c0, 0	@ write VBAR
+
+	mrs	r2, cpsr
+
+	/*
+	 * Input r0 is the stack top, which is the exception stacks base
+	 * The first frame is reserved for svc mode
+	 */
+	set_mode_stack	UND_MODE, r0
+	set_mode_stack	ABT_MODE, r0
+	set_mode_stack	IRQ_MODE, r0
+	set_mode_stack	FIQ_MODE, r0
+
+	msr	cpsr_cxsf, r2		@ back to svc mode
+	isb
+	mov	pc, lr
+
 /*
  * Vector stubs
  * Simplified version of the Linux kernel implementation
diff --git a/arm/cstart64.S b/arm/cstart64.S
index 0a85338bcdae..d39cf4dfb99c 100644
--- a/arm/cstart64.S
+++ b/arm/cstart64.S
@@ -89,10 +89,12 @@ start:
 	msr	cpacr_el1, x4
 
 	/* set up exception handling */
+	mov	x4, x0				// x0 is the addr of the dtb
 	bl	exceptions_init
 
 	/* complete setup */
-	bl	setup				// x0 is the addr of the dtb
+	mov	x0, x4				// restore the addr of the dtb
+	bl	setup
 	bl	get_mmu_off
 	cbnz	x0, 1f
 	bl	setup_vm
@@ -109,13 +111,6 @@ start:
 	bl	exit
 	b	halt
 
-exceptions_init:
-	adrp	x4, vector_table
-	add	x4, x4, :lo12:vector_table
-	msr	vbar_el1, x4
-	isb
-	ret
-
 .text
 
 .globl get_mmu_off
@@ -251,6 +246,17 @@ asm_mmu_disable:
 
 /*
  * Vectors
+ */
+
+exceptions_init:
+	adrp	x0, vector_table
+	add	x0, x0, :lo12:vector_table
+	msr	vbar_el1, x0
+	isb
+	ret
+
+/*
+ * Vector stubs
  * Adapted from arch/arm64/kernel/entry.S
  */
 .macro vector_stub, name, vec
-- 
2.26.3