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