1/* 2 * kexec for arm64 3 * 4 * Copyright (C) Linaro. 5 * Copyright (C) Huawei Futurewei Technologies. 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 */ 11 12#include <linux/kexec.h> 13#include <linux/linkage.h> 14 15#include <asm/assembler.h> 16#include <asm/kexec.h> 17#include <asm/page.h> 18#include <asm/sysreg.h> 19 20/* 21 * arm64_relocate_new_kernel - Put a 2nd stage image in place and boot it. 22 * 23 * The memory that the old kernel occupies may be overwritten when coping the 24 * new image to its final location. To assure that the 25 * arm64_relocate_new_kernel routine which does that copy is not overwritten, 26 * all code and data needed by arm64_relocate_new_kernel must be between the 27 * symbols arm64_relocate_new_kernel and arm64_relocate_new_kernel_end. The 28 * machine_kexec() routine will copy arm64_relocate_new_kernel to the kexec 29 * control_code_page, a special page which has been set up to be preserved 30 * during the copy operation. 31 */ 32ENTRY(arm64_relocate_new_kernel) 33 34 /* Setup the list loop variables. */ 35 mov x17, x1 /* x17 = kimage_start */ 36 mov x16, x0 /* x16 = kimage_head */ 37 raw_dcache_line_size x15, x0 /* x15 = dcache line size */ 38 mov x14, xzr /* x14 = entry ptr */ 39 mov x13, xzr /* x13 = copy dest */ 40 41 /* Clear the sctlr_el2 flags. */ 42 mrs x0, CurrentEL 43 cmp x0, #CurrentEL_EL2 44 b.ne 1f 45 mrs x0, sctlr_el2 46 ldr x1, =SCTLR_ELx_FLAGS 47 bic x0, x0, x1 48 pre_disable_mmu_workaround 49 msr sctlr_el2, x0 50 isb 511: 52 53 /* Check if the new image needs relocation. */ 54 tbnz x16, IND_DONE_BIT, .Ldone 55 56.Lloop: 57 and x12, x16, PAGE_MASK /* x12 = addr */ 58 59 /* Test the entry flags. */ 60.Ltest_source: 61 tbz x16, IND_SOURCE_BIT, .Ltest_indirection 62 63 /* Invalidate dest page to PoC. */ 64 mov x0, x13 65 add x20, x0, #PAGE_SIZE 66 sub x1, x15, #1 67 bic x0, x0, x1 682: dc ivac, x0 69 add x0, x0, x15 70 cmp x0, x20 71 b.lo 2b 72 dsb sy 73 74 mov x20, x13 75 mov x21, x12 76 copy_page x20, x21, x0, x1, x2, x3, x4, x5, x6, x7 77 78 /* dest += PAGE_SIZE */ 79 add x13, x13, PAGE_SIZE 80 b .Lnext 81 82.Ltest_indirection: 83 tbz x16, IND_INDIRECTION_BIT, .Ltest_destination 84 85 /* ptr = addr */ 86 mov x14, x12 87 b .Lnext 88 89.Ltest_destination: 90 tbz x16, IND_DESTINATION_BIT, .Lnext 91 92 /* dest = addr */ 93 mov x13, x12 94 95.Lnext: 96 /* entry = *ptr++ */ 97 ldr x16, [x14], #8 98 99 /* while (!(entry & DONE)) */ 100 tbz x16, IND_DONE_BIT, .Lloop 101 102.Ldone: 103 /* wait for writes from copy_page to finish */ 104 dsb nsh 105 ic iallu 106 dsb nsh 107 isb 108 109 /* Start new image. */ 110 mov x0, xzr 111 mov x1, xzr 112 mov x2, xzr 113 mov x3, xzr 114 br x17 115 116ENDPROC(arm64_relocate_new_kernel) 117 118.ltorg 119 120.align 3 /* To keep the 64-bit values below naturally aligned. */ 121 122.Lcopy_end: 123.org KEXEC_CONTROL_PAGE_SIZE 124 125/* 126 * arm64_relocate_new_kernel_size - Number of bytes to copy to the 127 * control_code_page. 128 */ 129.globl arm64_relocate_new_kernel_size 130arm64_relocate_new_kernel_size: 131 .quad .Lcopy_end - arm64_relocate_new_kernel 132