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-rw-r--r--arch/sh/kernel/relocate_kernel.S230
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diff --git a/arch/sh/kernel/relocate_kernel.S b/arch/sh/kernel/relocate_kernel.S
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+++ b/arch/sh/kernel/relocate_kernel.S
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+/* 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