1 files changed, 230 insertions, 0 deletions
diff --git a/arch/sh/kernel/relocate_kernel.S b/arch/sh/kernel/relocate_kernel.S
new file mode 100644
index 000000000..d9bf2b727
--- /dev/null
+++ b/arch/sh/kernel/relocate_kernel.S
@@ -0,0 +1,230 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * relocate_kernel.S - put the kernel image in place to boot
+ * 2005.9.17 kogiidena@eggplant.ddo.jp
+ *
+ * LANDISK/sh4 is supported. Maybe, SH archtecture works well.
+ *
+ * 2009-03-18 Magnus Damm - Added Kexec Jump support
+ */
+#include <linux/linkage.h>
+#include <asm/addrspace.h>
+#include <asm/page.h>
+
+		.globl relocate_new_kernel
+relocate_new_kernel:
+	/* r4 = indirection_page   */
+	/* r5 = reboot_code_buffer */
+	/* r6 = start_address      */
+
+	mov.l	10f, r0		/* PAGE_SIZE */
+	add	r5, r0		/* setup new stack at end of control page */
+
+	/* save r15->r8 to new stack */
+	mov.l	r15, @-r0
+	mov	r0, r15
+	mov.l	r14, @-r15
+	mov.l	r13, @-r15
+	mov.l	r12, @-r15
+	mov.l	r11, @-r15
+	mov.l	r10, @-r15
+	mov.l	r9, @-r15
+	mov.l	r8, @-r15
+
+	/* save other random registers */
+	sts.l	macl, @-r15
+	sts.l	mach, @-r15
+	stc.l	gbr, @-r15
+	stc.l	ssr, @-r15
+	stc.l	sr, @-r15
+	sts.l	pr, @-r15
+	stc.l	spc, @-r15
+
+	/* switch to bank1 and save r7->r0 */
+	mov.l	12f, r9
+	stc	sr, r8
+	or	r9, r8
+	ldc	r8, sr
+	mov.l	r7, @-r15
+	mov.l	r6, @-r15
+	mov.l	r5, @-r15
+	mov.l	r4, @-r15
+	mov.l	r3, @-r15
+	mov.l	r2, @-r15
+	mov.l	r1, @-r15
+	mov.l	r0, @-r15
+
+	/* switch to bank0 and save r7->r0 */
+	mov.l	12f, r9
+	not	r9, r9
+	stc	sr, r8
+	and	r9, r8
+	ldc	r8, sr
+	mov.l	r7, @-r15
+	mov.l	r6, @-r15
+	mov.l	r5, @-r15
+	mov.l	r4, @-r15
+	mov.l	r3, @-r15
+	mov.l	r2, @-r15
+	mov.l	r1, @-r15
+	mov.l	r0, @-r15
+
+	mov.l	r4, @-r15	/* save indirection page again */
+
+	bsr	swap_pages	/* swap pages before jumping to new kernel */
+	 nop
+
+	mova	11f, r0
+	mov.l	r15, @r0	/* save pointer to stack */
+
+	jsr	@r6		/* hand over control to new kernel */
+	 nop
+
+	mov.l	11f, r15	/* get pointer to stack */
+	mov.l	@r15+, r4	/* restore r4 to get indirection page */
+
+	bsr	swap_pages	/* swap pages back to previous state */
+	 nop
+
+	/* make sure bank0 is active and restore r0->r7 */
+	mov.l	12f, r9
+	not	r9, r9
+	stc	sr, r8
+	and	r9, r8
+	ldc	r8, sr
+	mov.l	@r15+, r0
+	mov.l	@r15+, r1
+	mov.l	@r15+, r2
+	mov.l	@r15+, r3
+	mov.l	@r15+, r4
+	mov.l	@r15+, r5
+	mov.l	@r15+, r6
+	mov.l	@r15+, r7
+
+	/* switch to bank1 and restore r0->r7 */
+	mov.l	12f, r9
+	stc	sr, r8
+	or	r9, r8
+	ldc	r8, sr
+	mov.l	@r15+, r0
+	mov.l	@r15+, r1
+	mov.l	@r15+, r2
+	mov.l	@r15+, r3
+	mov.l	@r15+, r4
+	mov.l	@r15+, r5
+	mov.l	@r15+, r6
+	mov.l	@r15+, r7
+
+	/* switch back to bank0 */
+	mov.l	12f, r9
+	not	r9, r9
+	stc	sr, r8
+	and	r9, r8
+	ldc	r8, sr
+
+	/* restore other random registers */
+	ldc.l	@r15+, spc
+	lds.l	@r15+, pr
+	ldc.l	@r15+, sr
+	ldc.l	@r15+, ssr
+	ldc.l	@r15+, gbr
+	lds.l	@r15+, mach
+	lds.l	@r15+, macl
+
+	/* restore r8->r15 */
+	mov.l	@r15+, r8
+	mov.l	@r15+, r9
+	mov.l	@r15+, r10
+	mov.l	@r15+, r11
+	mov.l	@r15+, r12
+	mov.l	@r15+, r13
+	mov.l	@r15+, r14
+	mov.l	@r15+, r15
+	rts
+	 nop
+
+swap_pages:
+	bra	1f
+	 mov	r4,r0	  /* cmd = indirection_page */
+0:
+	mov.l	@r4+,r0	  /* cmd = *ind++ */
+
+1:	/* addr = cmd & 0xfffffff0 */
+	mov	r0,r2
+	mov	#-16,r1
+	and	r1,r2
+
+	/* if(cmd & IND_DESTINATION) dst = addr  */
+	tst	#1,r0
+	bt	2f
+	bra	0b
+	 mov	r2,r5
+
+2:	/* else if(cmd & IND_INDIRECTION) ind = addr  */
+	tst	#2,r0
+	bt	3f
+	bra	0b
+	 mov	r2,r4
+
+3:	/* else if(cmd & IND_DONE) return */
+	tst	#4,r0
+	bt	4f
+	rts
+	 nop
+
+4:	/* else if(cmd & IND_SOURCE) memcpy(dst,addr,PAGE_SIZE) */
+	tst	#8,r0
+	bt	0b
+
+	mov.l	10f,r3	  /* PAGE_SIZE */
+	shlr2	r3
+	shlr2	r3
+5:
+	dt	r3
+
+	/* regular kexec just overwrites the destination page
+	 * with the contents of the source page.
+	 * for the kexec jump case we need to swap the contents
+	 * of the pages.
+	 * to keep it simple swap the contents for both cases.
+	 */
+	mov.l	@(0, r2), r8
+	mov.l	@(0, r5), r1
+	mov.l	r8, @(0, r5)
+	mov.l	r1, @(0, r2)
+
+	mov.l	@(4, r2), r8
+	mov.l	@(4, r5), r1
+	mov.l	r8, @(4, r5)
+	mov.l	r1, @(4, r2)
+
+	mov.l	@(8, r2), r8
+	mov.l	@(8, r5), r1
+	mov.l	r8, @(8, r5)
+	mov.l	r1, @(8, r2)
+
+	mov.l	@(12, r2), r8
+	mov.l	@(12, r5), r1
+	mov.l	r8, @(12, r5)
+	mov.l	r1, @(12, r2)
+
+	add	#16,r5
+	add	#16,r2
+	bf	5b
+
+	bra	0b
+	 nop
+
+	.align 2
+10:
+	.long	PAGE_SIZE
+11:
+	.long	0
+12:
+	.long	0x20000000 ! RB=1
+
+relocate_new_kernel_end:
+
+	.globl relocate_new_kernel_size
+relocate_new_kernel_size:
+	.long relocate_new_kernel_end - relocate_new_kernel