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 14LEAF(relocate_new_kernel) 15 PTR_L a0, arg0 16 PTR_L a1, arg1 17 PTR_L a2, arg2 18 PTR_L a3, arg3 19 20 PTR_L s0, kexec_indirection_page 21 PTR_L s1, kexec_start_address 22 23process_entry: 24 PTR_L s2, (s0) 25 PTR_ADDIU s0, s0, SZREG 26 27 /* 28 * In case of a kdump/crash kernel, the indirection page is not 29 * populated as the kernel is directly copied to a reserved location 30 */ 31 beqz s2, done 32 33 /* destination page */ 34 and s3, s2, 0x1 35 beq s3, zero, 1f 36 and s4, s2, ~0x1 /* store destination addr in s4 */ 37 b process_entry 38 391: 40 /* indirection page, update s0 */ 41 and s3, s2, 0x2 42 beq s3, zero, 1f 43 and s0, s2, ~0x2 44 b process_entry 45 461: 47 /* done page */ 48 and s3, s2, 0x4 49 beq s3, zero, 1f 50 b done 511: 52 /* source page */ 53 and s3, s2, 0x8 54 beq s3, zero, process_entry 55 and s2, s2, ~0x8 56 li s6, (1 << _PAGE_SHIFT) / SZREG 57 58copy_word: 59 /* copy page word by word */ 60 REG_L s5, (s2) 61 REG_S s5, (s4) 62 PTR_ADDIU s4, s4, SZREG 63 PTR_ADDIU s2, s2, SZREG 64 LONG_ADDIU s6, s6, -1 65 beq s6, zero, process_entry 66 b copy_word 67 b process_entry 68 69done: 70#ifdef CONFIG_SMP 71 /* kexec_flag reset is signal to other CPUs what kernel 72 was moved to it's location. Note - we need relocated address 73 of kexec_flag. */ 74 75 bal 1f 76 1: move t1,ra; 77 PTR_LA t2,1b 78 PTR_LA t0,kexec_flag 79 PTR_SUB t0,t0,t2; 80 PTR_ADD t0,t1,t0; 81 LONG_S zero,(t0) 82#endif 83 84#ifdef CONFIG_CPU_CAVIUM_OCTEON 85 /* We need to flush I-cache before jumping to new kernel. 86 * Unfortunately, this code is cpu-specific. 87 */ 88 .set push 89 .set noreorder 90 syncw 91 syncw 92 synci 0($0) 93 .set pop 94#else 95 sync 96#endif 97 /* jump to kexec_start_address */ 98 j s1 99 END(relocate_new_kernel) 100 101#ifdef CONFIG_SMP 102/* 103 * Other CPUs should wait until code is relocated and 104 * then start at entry (?) point. 105 */ 106LEAF(kexec_smp_wait) 107 PTR_L a0, s_arg0 108 PTR_L a1, s_arg1 109 PTR_L a2, s_arg2 110 PTR_L a3, s_arg3 111 PTR_L s1, kexec_start_address 112 113 /* Non-relocated address works for args and kexec_start_address ( old 114 * kernel is not overwritten). But we need relocated address of 115 * kexec_flag. 116 */ 117 118 bal 1f 1191: move t1,ra; 120 PTR_LA t2,1b 121 PTR_LA t0,kexec_flag 122 PTR_SUB t0,t0,t2; 123 PTR_ADD t0,t1,t0; 124 1251: LONG_L s0, (t0) 126 bne s0, zero,1b 127 128#ifdef CONFIG_CPU_CAVIUM_OCTEON 129 .set push 130 .set noreorder 131 synci 0($0) 132 .set pop 133#else 134 sync 135#endif 136 j s1 137 END(kexec_smp_wait) 138#endif 139 140#ifdef __mips64 141 /* all PTR's must be aligned to 8 byte in 64-bit mode */ 142 .align 3 143#endif 144 145/* All parameters to new kernel are passed in registers a0-a3. 146 * kexec_args[0..3] are used to prepare register values. 147 */ 148 149kexec_args: 150 EXPORT(kexec_args) 151arg0: PTR 0x0 152arg1: PTR 0x0 153arg2: PTR 0x0 154arg3: PTR 0x0 155 .size kexec_args,PTRSIZE*4 156 157#ifdef CONFIG_SMP 158/* 159 * Secondary CPUs may have different kernel parameters in 160 * their registers a0-a3. secondary_kexec_args[0..3] are used 161 * to prepare register values. 162 */ 163secondary_kexec_args: 164 EXPORT(secondary_kexec_args) 165s_arg0: PTR 0x0 166s_arg1: PTR 0x0 167s_arg2: PTR 0x0 168s_arg3: PTR 0x0 169 .size secondary_kexec_args,PTRSIZE*4 170kexec_flag: 171 LONG 0x1 172 173#endif 174 175kexec_start_address: 176 EXPORT(kexec_start_address) 177 PTR 0x0 178 .size kexec_start_address, PTRSIZE 179 180kexec_indirection_page: 181 EXPORT(kexec_indirection_page) 182 PTR 0 183 .size kexec_indirection_page, PTRSIZE 184 185relocate_new_kernel_end: 186 187relocate_new_kernel_size: 188 EXPORT(relocate_new_kernel_size) 189 PTR relocate_new_kernel_end - relocate_new_kernel 190 .size relocate_new_kernel_size, PTRSIZE 191