1 files changed, 130 insertions, 0 deletions

diff --git a/arch/arm64/kernel/relocate_kernel.S b/arch/arm64/kernel/relocate_kernel.S
new file mode 100644
index 000000000000..51b73cdde287
--- /dev/null
+++ b/arch/arm64/kernel/relocate_kernel.S
@@ -0,0 +1,130 @@
+/*
+ * kexec for arm64
+ *
+ * Copyright (C) Linaro.
+ * Copyright (C) Huawei Futurewei Technologies.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kexec.h>
+#include <linux/linkage.h>
+
+#include <asm/assembler.h>
+#include <asm/kexec.h>
+#include <asm/page.h>
+#include <asm/sysreg.h>
+
+/*
+ * arm64_relocate_new_kernel - Put a 2nd stage image in place and boot it.
+ *
+ * The memory that the old kernel occupies may be overwritten when coping the
+ * new image to its final location.  To assure that the
+ * arm64_relocate_new_kernel routine which does that copy is not overwritten,
+ * all code and data needed by arm64_relocate_new_kernel must be between the
+ * symbols arm64_relocate_new_kernel and arm64_relocate_new_kernel_end.  The
+ * machine_kexec() routine will copy arm64_relocate_new_kernel to the kexec
+ * control_code_page, a special page which has been set up to be preserved
+ * during the copy operation.
+ */
+ENTRY(arm64_relocate_new_kernel)
+
+        /* Setup the list loop variables. */
+        mov     x17, x1                         /* x17 = kimage_start */
+        mov     x16, x0                         /* x16 = kimage_head */
+        dcache_line_size x15, x0                /* x15 = dcache line size */
+        mov     x14, xzr                        /* x14 = entry ptr */
+        mov     x13, xzr                        /* x13 = copy dest */
+
+        /* Clear the sctlr_el2 flags. */
+        mrs     x0, CurrentEL
+        cmp     x0, #CurrentEL_EL2
+        b.ne    1f
+        mrs     x0, sctlr_el2
+        ldr     x1, =SCTLR_ELx_FLAGS
+        bic     x0, x0, x1
+        msr     sctlr_el2, x0
+        isb
+1:
+
+        /* Check if the new image needs relocation. */
+        tbnz    x16, IND_DONE_BIT, .Ldone
+
+.Lloop:
+        and     x12, x16, PAGE_MASK             /* x12 = addr */
+
+        /* Test the entry flags. */
+.Ltest_source:
+        tbz     x16, IND_SOURCE_BIT, .Ltest_indirection
+
+        /* Invalidate dest page to PoC. */
+        mov     x0, x13
+        add     x20, x0, #PAGE_SIZE
+        sub     x1, x15, #1
+        bic     x0, x0, x1
+2:      dc      ivac, x0
+        add     x0, x0, x15
+        cmp     x0, x20
+        b.lo    2b
+        dsb     sy
+
+        mov x20, x13
+        mov x21, x12
+        copy_page x20, x21, x0, x1, x2, x3, x4, x5, x6, x7
+
+        /* dest += PAGE_SIZE */
+        add     x13, x13, PAGE_SIZE
+        b       .Lnext
+
+.Ltest_indirection:
+        tbz     x16, IND_INDIRECTION_BIT, .Ltest_destination
+
+        /* ptr = addr */
+        mov     x14, x12
+        b       .Lnext
+
+.Ltest_destination:
+        tbz     x16, IND_DESTINATION_BIT, .Lnext
+
+        /* dest = addr */
+        mov     x13, x12
+
+.Lnext:
+        /* entry = *ptr++ */
+        ldr     x16, [x14], #8
+
+        /* while (!(entry & DONE)) */
+        tbz     x16, IND_DONE_BIT, .Lloop
+
+.Ldone:
+        /* wait for writes from copy_page to finish */
+        dsb     nsh
+        ic      iallu
+        dsb     nsh
+        isb
+
+        /* Start new image. */
+        mov     x0, xzr
+        mov     x1, xzr
+        mov     x2, xzr
+        mov     x3, xzr
+        br      x17
+
+ENDPROC(arm64_relocate_new_kernel)
+
+.ltorg
+
+.align 3        /* To keep the 64-bit values below naturally aligned. */
+
+.Lcopy_end:
+.org    KEXEC_CONTROL_PAGE_SIZE
+
+/*
+ * arm64_relocate_new_kernel_size - Number of bytes to copy to the
+ * control_code_page.
+ */
+.globl arm64_relocate_new_kernel_size
+arm64_relocate_new_kernel_size:
+        .quad   .Lcopy_end - arm64_relocate_new_kernel