/* SPDX-License-Identifier: GPL-2.0 */ /* * relocate_kernel.S for kexec * Created by on Thu Oct 12 17:49:57 2006 * Copyright (C) 2020 Loongson Technology Co., Ltd. * * This source code is licensed under the GNU General Public License, * Version 2. See the file COPYING for more details. */ #include #include #include #include #include #include SYM_CODE_START(relocate_new_kernel) la t0, arg0 PTR_L a0, t0, 0 la t0, arg1 PTR_L a1, t0, 0 la t0, arg2 PTR_L a2, t0, 0 la t0, arg3 PTR_L a3, t0, 0 la t0, kexec_indirection_page PTR_L s0, t0, 0 la t0, kexec_start_address PTR_L s1, t0, 0 process_entry: PTR_L s2, s0, 0 PTR_ADDIU s0, s0, SZREG /* * In case of a kdump/crash kernel, the indirection page is not * populated as the kernel is directly copied to a reserved location */ beqz s2, done /* destination page */ andi s3, s2, 0x1 beq s3, zero, 1f li.w t0, ~0x1 and s4, s2, t0 /* store destination addr in s4 */ b process_entry 1: /* indirection page, update s0 */ andi s3, s2, 0x2 beq s3, zero, 1f li.w t0, ~0x2 and s0, s2, t0 b process_entry 1: /* done page */ andi s3, s2, 0x4 beq s3, zero, 1f b done 1: /* source page */ andi s3, s2, 0x8 beq s3, zero, process_entry li.w t0, ~0x8 and s2, s2, t0 li.w s6, (1 << _PAGE_SHIFT) / SZREG copy_word: /* copy page word by word */ REG_L s5, s2, 0 REG_S s5, s4, 0 PTR_ADDIU s4, s4, SZREG PTR_ADDIU s2, s2, SZREG LONG_ADDIU s6, s6, -1 beq s6, zero, process_entry b copy_word b process_entry done: #ifdef CONFIG_SMP /* * kexec_flag reset is signal to other CPUs what kernel * was moved to it's location. Note - we need relocated * address of kexec_flag. */ bl 1f 1: move t1,ra; la t2,1b la t0,kexec_flag PTR_SUBU t0,t0,t2; PTR_ADDU t0,t1,t0; LONG_S zero,t0,0 #endif dbar 0 /* jump to kexec_start_address */ jr s1 SYM_CODE_END(relocate_new_kernel) #ifdef CONFIG_SMP /* * Other CPUs should wait until code is relocated and * then start at entry (?) point. */ SYM_CODE_START(kexec_smp_wait) la t0, s_arg0 PTR_L a0, t0, 0 la t0, s_arg1 PTR_L a1, t0, 0 la t0, s_arg2 PTR_L a2, t0, 0 la t0, s_arg3 PTR_L a3, t0, 0 la t0, kexec_start_address PTR_L s1, t0, 0 /* * Non-relocated address works for args and kexec_start_address (old * kernel is not overwritten). But we need relocated address of * kexec_flag. */ bl 1f 1: move t1,ra; la t2,1b la t0,kexec_flag PTR_SUBU t0,t0,t2; PTR_ADDU t0,t1,t0; 1: LONG_L s0, t0, 0 bne s0, zero,1b dbar 0 #ifdef CONFIG_CPU_LOONGSON64 /* * s1:initfn * a0:base t1:cpuid t2:node t3:core t4:count */ csrrd t1, LOONGARCH_CSR_CPUID andi t1, t1, CSR_CPUID_COREID andi t3, t1, 0x3 slli.w t3, t3, 8 /* get core id */ or a0, a0, t3 andi t2, t1, 0x3c slli.d t2, t2, 42 /* get node id */ or a0, a0, t2 1: li.w t4, 0x100 /* wait for init loop */ 2: addi.w t4, t4, -1 /* limit mailbox access */ bnez t4, 2b ld.w s1, a0, 0x20 /* check PC as an indicator */ beqz s1, 1b ld.d s1, a0, 0x20 /* get PC via mailbox */ ld.d sp, a0, 0x28 /* get SP via mailbox */ ld.d tp, a0, 0x30 /* get TP via mailbox */ ld.d a1, a0, 0x38 #endif jr s1 /* jump to initial PC */ SYM_CODE_END(kexec_smp_wait) #endif #ifdef __loongarch64 /* all PTR's must be aligned to 8 byte in 64-bit mode */ .align 3 #endif /* * All parameters to new kernel are passed in registers a0-a3. * kexec_args[0..3] are used to prepare register values. */ SYM_DATA_START(kexec_args) arg0: PTR 0x0 arg1: PTR 0x0 arg2: PTR 0x0 arg3: PTR 0x0 SYM_DATA_END(kexec_args) #ifdef CONFIG_SMP /* * Secondary CPUs may have different kernel parameters in * their registers a0-a3. secondary_kexec_args[0..3] are used * to prepare register values. */ SYM_DATA_START(secondary_kexec_args) s_arg0: PTR 0x0 s_arg1: PTR 0x0 s_arg2: PTR 0x0 s_arg3: PTR 0x0 SYM_DATA_END(secondary_kexec_args) SYM_DATA_START(kexec_flag) LONG 0x1 SYM_DATA_END(kexec_flag) #endif SYM_DATA_START(kexec_start_address) PTR 0x0 SYM_DATA_END(kexec_start_address) SYM_DATA_START(kexec_indirection_page) PTR 0 SYM_DATA_END(kexec_indirection_page) relocate_new_kernel_end: SYM_DATA_START(relocate_new_kernel_size) PTR relocate_new_kernel_end - relocate_new_kernel SYM_DATA_END(relocate_new_kernel_size)