1/* 2 * relocate_kernel.S for kexec 3 * Created by <nschichan@corp.free.fr> on Thu Oct 12 17:49:57 2006 4 * 5 * This source code is licensed under the GNU General Public License, 6 * Version 2. See the file COPYING for more details. 7 */ 8 9#include <asm/asm.h> 10#include <asm/asmmacro.h> 11#include <asm/regdef.h> 12#include <asm/mipsregs.h> 13#include <asm/stackframe.h> 14#include <asm/addrspace.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 * Unfortunatelly, 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 CONFIG_CPU_CAVIUM_OCTEON 131 .set push 132 .set noreorder 133 synci 0($0) 134 .set pop 135#else 136 sync 137#endif 138 j s1 139 END(kexec_smp_wait) 140#endif 141 142#ifdef __mips64 143 /* all PTR's must be aligned to 8 byte in 64-bit mode */ 144 .align 3 145#endif 146 147/* All parameters to new kernel are passed in registers a0-a3. 148 * kexec_args[0..3] are uses to prepare register values. 149 */ 150 151kexec_args: 152 EXPORT(kexec_args) 153arg0: PTR 0x0 154arg1: PTR 0x0 155arg2: PTR 0x0 156arg3: PTR 0x0 157 .size kexec_args,PTRSIZE*4 158 159#ifdef CONFIG_SMP 160/* 161 * Secondary CPUs may have different kernel parameters in 162 * their registers a0-a3. secondary_kexec_args[0..3] are used 163 * to prepare register values. 164 */ 165secondary_kexec_args: 166 EXPORT(secondary_kexec_args) 167s_arg0: PTR 0x0 168s_arg1: PTR 0x0 169s_arg2: PTR 0x0 170s_arg3: PTR 0x0 171 .size secondary_kexec_args,PTRSIZE*4 172kexec_flag: 173 LONG 0x1 174 175#endif 176 177kexec_start_address: 178 EXPORT(kexec_start_address) 179 PTR 0x0 180 .size kexec_start_address, PTRSIZE 181 182kexec_indirection_page: 183 EXPORT(kexec_indirection_page) 184 PTR 0 185 .size kexec_indirection_page, PTRSIZE 186 187relocate_new_kernel_end: 188 189relocate_new_kernel_size: 190 EXPORT(relocate_new_kernel_size) 191 PTR relocate_new_kernel_end - relocate_new_kernel 192 .size relocate_new_kernel_size, PTRSIZE 193