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-rw-r--r--arch/s390/kernel/relocate_kernel.S78
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diff --git a/arch/s390/kernel/relocate_kernel.S b/arch/s390/kernel/relocate_kernel.S
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+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright IBM Corp. 2005
+ *
+ * Author(s): Rolf Adelsberger
+ *
+ */
+
+#include <linux/linkage.h>
+#include <asm/page.h>
+#include <asm/sigp.h>
+
+/*
+ * moves the new kernel to its destination...
+ * %r2 = pointer to first kimage_entry_t
+ * %r3 = start address - where to jump to after the job is done...
+ * %r4 = subcode
+ *
+ * %r5 will be used as temp. storage
+ * %r6 holds the destination address
+ * %r7 = PAGE_SIZE
+ * %r8 holds the source address
+ * %r9 = PAGE_SIZE
+ *
+ * 0xf000 is a page_mask
+ */
+
+ .text
+ENTRY(relocate_kernel)
+ basr %r13,0 # base address
+ .base:
+ lghi %r7,PAGE_SIZE # load PAGE_SIZE in r7
+ lghi %r9,PAGE_SIZE # load PAGE_SIZE in r9
+ lg %r5,0(%r2) # read another word for indirection page
+ aghi %r2,8 # increment pointer
+ tml %r5,0x1 # is it a destination page?
+ je .indir_check # NO, goto "indir_check"
+ lgr %r6,%r5 # r6 = r5
+ nill %r6,0xf000 # mask it out and...
+ j .base # ...next iteration
+ .indir_check:
+ tml %r5,0x2 # is it a indirection page?
+ je .done_test # NO, goto "done_test"
+ nill %r5,0xf000 # YES, mask out,
+ lgr %r2,%r5 # move it into the right register,
+ j .base # and read next...
+ .done_test:
+ tml %r5,0x4 # is it the done indicator?
+ je .source_test # NO! Well, then it should be the source indicator...
+ j .done # ok, lets finish it here...
+ .source_test:
+ tml %r5,0x8 # it should be a source indicator...
+ je .base # NO, ignore it...
+ lgr %r8,%r5 # r8 = r5
+ nill %r8,0xf000 # masking
+ 0: mvcle %r6,%r8,0x0 # copy PAGE_SIZE bytes from r8 to r6 - pad with 0
+ jo 0b
+ j .base
+ .done:
+ lgr %r0,%r4 # subcode
+ cghi %r3,0
+ je .diag
+ la %r4,load_psw-.base(%r13) # load psw-address into the register
+ o %r3,4(%r4) # or load address into psw
+ st %r3,4(%r4)
+ mvc 0(8,%r0),0(%r4) # copy psw to absolute address 0
+ .diag:
+ diag %r0,%r0,0x308
+ENDPROC(relocate_kernel)
+
+ .align 8
+ load_psw:
+ .long 0x00080000,0x80000000
+ relocate_kernel_end:
+ .align 8
+ .globl relocate_kernel_len
+ relocate_kernel_len:
+ .quad relocate_kernel_end - relocate_kernel