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 16 LEAF(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 25 process_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 41 1: 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 48 1: 49 /* done page */ 50 and s3, s2, 0x4 51 beq s3, zero, 1f 52 b done 53 1: 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 60 copy_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 70 done: 71 #ifdef CONFIG_SMP 72 /* kexec_flag reset is signal to other CPUs what kernel 73 was moved to its 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 */ 107 LEAF(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 120 1: 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; 125 126 1: 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 */ 146 147 EXPORT(kexec_args) 148 arg0: PTR_WD 0x0 149 arg1: PTR_WD 0x0 150 arg2: PTR_WD 0x0 151 arg3: 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 */ 160 EXPORT(secondary_kexec_args) 161 s_arg0: PTR_WD 0x0 162 s_arg1: PTR_WD 0x0 163 s_arg2: PTR_WD 0x0 164 s_arg3: PTR_WD 0x0 165 .size secondary_kexec_args,PTRSIZE*4 166 kexec_flag: 167 LONG 0x1 168 169 #endif 170 171 EXPORT(kexec_start_address) 172 PTR_WD 0x0 173 .size kexec_start_address, PTRSIZE 174 175 EXPORT(kexec_indirection_page) 176 PTR_WD 0 177 .size kexec_indirection_page, PTRSIZE 178 179 relocate_new_kernel_end: 180 181 EXPORT(relocate_new_kernel_size) 182 PTR_WD relocate_new_kernel_end - relocate_new_kernel 183 .size relocate_new_kernel_size, PTRSIZE
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