1/* SPDX-License-Identifier: GPL-2.0-only */ 2/* 3 * relocate_kernel.S for kexec 4 * Created by <nschichan@corp.free.fr> on Thu Oct 12 17:49:57 2006 5 */ 6 7#include <asm/asm.h> 8#include <asm/asmmacro.h> 9#include <asm/regdef.h> 10#include <asm/mipsregs.h> 11#include <asm/stackframe.h> 12#include <asm/addrspace.h> 13 14#include <kernel-entry-init.h> 15 16LEAF(relocate_new_kernel) 17 PTR_L a0, arg0 18 PTR_L a1, arg1 19 PTR_L a2, arg2 20 PTR_L a3, arg3 21 22 PTR_L s0, kexec_indirection_page 23 PTR_L s1, kexec_start_address 24 25process_entry: 26 PTR_L s2, (s0) 27 PTR_ADDIU s0, s0, SZREG 28 29 /* 30 * In case of a kdump/crash kernel, the indirection page is not 31 * populated as the kernel is directly copied to a reserved location 32 */ 33 beqz s2, done 34 35 /* destination page */ 36 and s3, s2, 0x1 37 beq s3, zero, 1f 38 and s4, s2, ~0x1 /* store destination addr in s4 */ 39 b process_entry 40 411: 42 /* indirection page, update s0 */ 43 and s3, s2, 0x2 44 beq s3, zero, 1f 45 and s0, s2, ~0x2 46 b process_entry 47 481: 49 /* done page */ 50 and s3, s2, 0x4 51 beq s3, zero, 1f 52 b done 531: 54 /* source page */ 55 and s3, s2, 0x8 56 beq s3, zero, process_entry 57 and s2, s2, ~0x8 58 li s6, (1 << _PAGE_SHIFT) / SZREG 59 60copy_word: 61 /* copy page word by word */ 62 REG_L s5, (s2) 63 REG_S s5, (s4) 64 PTR_ADDIU s4, s4, SZREG 65 PTR_ADDIU s2, s2, SZREG 66 LONG_ADDIU s6, s6, -1 67 beq s6, zero, process_entry 68 b copy_word 69 b process_entry 70 71done: 72#ifdef CONFIG_SMP 73 /* kexec_flag reset is signal to other CPUs what kernel 74 was moved to it's location. Note - we need relocated address 75 of kexec_flag. */ 76 77 bal 1f 78 1: move t1,ra; 79 PTR_LA t2,1b 80 PTR_LA t0,kexec_flag 81 PTR_SUB t0,t0,t2; 82 PTR_ADD t0,t1,t0; 83 LONG_S zero,(t0) 84#endif 85 86#ifdef CONFIG_CPU_CAVIUM_OCTEON 87 /* We need to flush I-cache before jumping to new kernel. 88 * Unfortunately, this code is cpu-specific. 89 */ 90 .set push 91 .set noreorder 92 syncw 93 syncw 94 synci 0($0) 95 .set pop 96#else 97 sync 98#endif 99 /* jump to kexec_start_address */ 100 j s1 101 END(relocate_new_kernel) 102 103#ifdef CONFIG_SMP 104/* 105 * Other CPUs should wait until code is relocated and 106 * then start at entry (?) point. 107 */ 108LEAF(kexec_smp_wait) 109 PTR_L a0, s_arg0 110 PTR_L a1, s_arg1 111 PTR_L a2, s_arg2 112 PTR_L a3, s_arg3 113 PTR_L s1, kexec_start_address 114 115 /* Non-relocated address works for args and kexec_start_address ( old 116 * kernel is not overwritten). But we need relocated address of 117 * kexec_flag. 118 */ 119 120 bal 1f 1211: move t1,ra; 122 PTR_LA t2,1b 123 PTR_LA t0,kexec_flag 124 PTR_SUB t0,t0,t2; 125 PTR_ADD t0,t1,t0; 126 1271: LONG_L s0, (t0) 128 bne s0, zero,1b 129 130#ifdef USE_KEXEC_SMP_WAIT_FINAL 131 kexec_smp_wait_final 132#else 133 sync 134#endif 135 j s1 136 END(kexec_smp_wait) 137#endif 138 139#ifdef __mips64 140 /* all PTR's must be aligned to 8 byte in 64-bit mode */ 141 .align 3 142#endif 143 144/* All parameters to new kernel are passed in registers a0-a3. 145 * kexec_args[0..3] are used to prepare register values. 146 */ 147 148kexec_args: 149 EXPORT(kexec_args) 150arg0: PTR 0x0 151arg1: PTR 0x0 152arg2: PTR 0x0 153arg3: PTR 0x0 154 .size kexec_args,PTRSIZE*4 155 156#ifdef CONFIG_SMP 157/* 158 * Secondary CPUs may have different kernel parameters in 159 * their registers a0-a3. secondary_kexec_args[0..3] are used 160 * to prepare register values. 161 */ 162secondary_kexec_args: 163 EXPORT(secondary_kexec_args) 164s_arg0: PTR 0x0 165s_arg1: PTR 0x0 166s_arg2: PTR 0x0 167s_arg3: PTR 0x0 168 .size secondary_kexec_args,PTRSIZE*4 169kexec_flag: 170 LONG 0x1 171 172#endif 173 174kexec_start_address: 175 EXPORT(kexec_start_address) 176 PTR 0x0 177 .size kexec_start_address, PTRSIZE 178 179kexec_indirection_page: 180 EXPORT(kexec_indirection_page) 181 PTR 0 182 .size kexec_indirection_page, PTRSIZE 183 184relocate_new_kernel_end: 185 186relocate_new_kernel_size: 187 EXPORT(relocate_new_kernel_size) 188 PTR relocate_new_kernel_end - relocate_new_kernel 189 .size relocate_new_kernel_size, PTRSIZE 190