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 70done: 71#ifdef CONFIG_SMP 72 /* kexec_flag reset is signal to other CPUs what kernel 73 was moved to it's location. Note - we need relocated address 74 of kexec_flag. */ 75 76 bal 1f 77 1: move t1,ra; 78 PTR_LA t2,1b 79 PTR_LA t0,kexec_flag 80 PTR_SUB t0,t0,t2; 81 PTR_ADD t0,t1,t0; 82 LONG_S zero,(t0) 83#endif 84 85#ifdef CONFIG_CPU_CAVIUM_OCTEON 86 /* We need to flush I-cache before jumping to new kernel. 87 * Unfortunately, this code is cpu-specific. 88 */ 89 .set push 90 .set noreorder 91 syncw 92 syncw 93 synci 0($0) 94 .set pop 95#else 96 sync 97#endif 98 /* jump to kexec_start_address */ 99 j s1 100 END(relocate_new_kernel) 101 102#ifdef CONFIG_SMP 103/* 104 * Other CPUs should wait until code is relocated and 105 * then start at entry (?) point. 106 */ 107LEAF(kexec_smp_wait) 108 PTR_L a0, s_arg0 109 PTR_L a1, s_arg1 110 PTR_L a2, s_arg2 111 PTR_L a3, s_arg3 112 PTR_L s1, kexec_start_address 113 114 /* Non-relocated address works for args and kexec_start_address ( old 115 * kernel is not overwritten). But we need relocated address of 116 * kexec_flag. 117 */ 118 119 bal 1f 1201: move t1,ra; 121 PTR_LA t2,1b 122 PTR_LA t0,kexec_flag 123 PTR_SUB t0,t0,t2; 124 PTR_ADD t0,t1,t0; 125 1261: LONG_L s0, (t0) 127 bne s0, zero,1b 128 129#ifdef USE_KEXEC_SMP_WAIT_FINAL 130 kexec_smp_wait_final 131#else 132 sync 133#endif 134 j s1 135 END(kexec_smp_wait) 136#endif 137 138#ifdef __mips64 139 /* all PTR's must be aligned to 8 byte in 64-bit mode */ 140 .align 3 141#endif 142 143/* All parameters to new kernel are passed in registers a0-a3. 144 * kexec_args[0..3] are used to prepare register values. 145 */ 146 147EXPORT(kexec_args) 148arg0: PTR_WD 0x0 149arg1: PTR_WD 0x0 150arg2: PTR_WD 0x0 151arg3: PTR_WD 0x0 152 .size kexec_args,PTRSIZE*4 153 154#ifdef CONFIG_SMP 155/* 156 * Secondary CPUs may have different kernel parameters in 157 * their registers a0-a3. secondary_kexec_args[0..3] are used 158 * to prepare register values. 159 */ 160EXPORT(secondary_kexec_args) 161s_arg0: PTR_WD 0x0 162s_arg1: PTR_WD 0x0 163s_arg2: PTR_WD 0x0 164s_arg3: PTR_WD 0x0 165 .size secondary_kexec_args,PTRSIZE*4 166kexec_flag: 167 LONG 0x1 168 169#endif 170 171EXPORT(kexec_start_address) 172 PTR_WD 0x0 173 .size kexec_start_address, PTRSIZE 174 175EXPORT(kexec_indirection_page) 176 PTR_WD 0 177 .size kexec_indirection_page, PTRSIZE 178 179relocate_new_kernel_end: 180 181EXPORT(relocate_new_kernel_size) 182 PTR_WD relocate_new_kernel_end - relocate_new_kernel 183 .size relocate_new_kernel_size, PTRSIZE 184