diff options
Diffstat (limited to 'arch/loongarch/kernel/head.S')
| -rw-r--r-- | arch/loongarch/kernel/head.S | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/head.S b/arch/loongarch/kernel/head.S new file mode 100644 index 0000000000..53b883db07 --- /dev/null +++ b/arch/loongarch/kernel/head.S @@ -0,0 +1,149 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited + */ +#include <linux/init.h> +#include <linux/threads.h> + +#include <asm/addrspace.h> +#include <asm/asm.h> +#include <asm/asmmacro.h> +#include <asm/bug.h> +#include <asm/regdef.h> +#include <asm/loongarch.h> +#include <asm/stackframe.h> + +#ifdef CONFIG_EFI_STUB + +#include "efi-header.S" + + __HEAD + +_head: + .word MZ_MAGIC /* "MZ", MS-DOS header */ + .org 0x8 + .dword kernel_entry /* Kernel entry point */ + .dword _kernel_asize /* Kernel image effective size */ + .quad PHYS_LINK_KADDR /* Kernel image load offset from start of RAM */ + .org 0x38 /* 0x20 ~ 0x37 reserved */ + .long LINUX_PE_MAGIC + .long pe_header - _head /* Offset to the PE header */ + +pe_header: + __EFI_PE_HEADER + +SYM_DATA(kernel_asize, .long _kernel_asize); +SYM_DATA(kernel_fsize, .long _kernel_fsize); +SYM_DATA(kernel_offset, .long _kernel_offset); + +#endif + + __REF + + .align 12 + +SYM_CODE_START(kernel_entry) # kernel entry point + + /* Config direct window and set PG */ + li.d t0, CSR_DMW0_INIT # UC, PLV0, 0x8000 xxxx xxxx xxxx + csrwr t0, LOONGARCH_CSR_DMWIN0 + li.d t0, CSR_DMW1_INIT # CA, PLV0, 0x9000 xxxx xxxx xxxx + csrwr t0, LOONGARCH_CSR_DMWIN1 + + JUMP_VIRT_ADDR t0, t1 + + /* Enable PG */ + li.w t0, 0xb0 # PLV=0, IE=0, PG=1 + csrwr t0, LOONGARCH_CSR_CRMD + li.w t0, 0x04 # PLV=0, PIE=1, PWE=0 + csrwr t0, LOONGARCH_CSR_PRMD + li.w t0, 0x00 # FPE=0, SXE=0, ASXE=0, BTE=0 + csrwr t0, LOONGARCH_CSR_EUEN + + la.pcrel t0, __bss_start # clear .bss + st.d zero, t0, 0 + la.pcrel t1, __bss_stop - LONGSIZE +1: + addi.d t0, t0, LONGSIZE + st.d zero, t0, 0 + bne t0, t1, 1b + + la.pcrel t0, fw_arg0 + st.d a0, t0, 0 # firmware arguments + la.pcrel t0, fw_arg1 + st.d a1, t0, 0 + la.pcrel t0, fw_arg2 + st.d a2, t0, 0 + + /* KSave3 used for percpu base, initialized as 0 */ + csrwr zero, PERCPU_BASE_KS + /* GPR21 used for percpu base (runtime), initialized as 0 */ + move u0, zero + + la.pcrel tp, init_thread_union + /* Set the SP after an empty pt_regs. */ + PTR_LI sp, (_THREAD_SIZE - PT_SIZE) + PTR_ADD sp, sp, tp + set_saved_sp sp, t0, t1 + +#ifdef CONFIG_RELOCATABLE + + bl relocate_kernel + +#ifdef CONFIG_RANDOMIZE_BASE + /* Repoint the sp into the new kernel */ + PTR_LI sp, (_THREAD_SIZE - PT_SIZE) + PTR_ADD sp, sp, tp + set_saved_sp sp, t0, t1 + + /* Jump to the new kernel: new_pc = current_pc + random_offset */ + pcaddi t0, 0 + add.d t0, t0, a0 + jirl zero, t0, 0xc +#endif /* CONFIG_RANDOMIZE_BASE */ + +#endif /* CONFIG_RELOCATABLE */ + +#ifdef CONFIG_KASAN + bl kasan_early_init +#endif + + bl start_kernel + ASM_BUG() + +SYM_CODE_END(kernel_entry) + +#ifdef CONFIG_SMP + +/* + * SMP slave cpus entry point. Board specific code for bootstrap calls this + * function after setting up the stack and tp registers. + */ +SYM_CODE_START(smpboot_entry) + li.d t0, CSR_DMW0_INIT # UC, PLV0 + csrwr t0, LOONGARCH_CSR_DMWIN0 + li.d t0, CSR_DMW1_INIT # CA, PLV0 + csrwr t0, LOONGARCH_CSR_DMWIN1 + + JUMP_VIRT_ADDR t0, t1 + + /* Enable PG */ + li.w t0, 0xb0 # PLV=0, IE=0, PG=1 + csrwr t0, LOONGARCH_CSR_CRMD + li.w t0, 0x04 # PLV=0, PIE=1, PWE=0 + csrwr t0, LOONGARCH_CSR_PRMD + li.w t0, 0x00 # FPE=0, SXE=0, ASXE=0, BTE=0 + csrwr t0, LOONGARCH_CSR_EUEN + + la.pcrel t0, cpuboot_data + ld.d sp, t0, CPU_BOOT_STACK + ld.d tp, t0, CPU_BOOT_TINFO + + bl start_secondary + ASM_BUG() + +SYM_CODE_END(smpboot_entry) + +#endif /* CONFIG_SMP */ + +SYM_ENTRY(kernel_entry_end, SYM_L_GLOBAL, SYM_A_NONE) |