diff options
Diffstat (limited to 'arch/loongarch/kernel/head.S')
| -rw-r--r-- | arch/loongarch/kernel/head.S | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/head.S b/arch/loongarch/kernel/head.S new file mode 100644 index 000000000000..e596dfcd924b --- /dev/null +++ b/arch/loongarch/kernel/head.S @@ -0,0 +1,98 @@ +/* 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/regdef.h> +#include <asm/loongarch.h> +#include <asm/stackframe.h> + + __REF + +SYM_ENTRY(_stext, SYM_L_GLOBAL, SYM_A_NONE) + +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 + /* 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 + + /* We might not get launched at the address the kernel is linked to, + so we jump there. */ + la.abs t0, 0f + jirl zero, t0, 0 +0: + la t0, __bss_start # clear .bss + st.d zero, t0, 0 + la t1, __bss_stop - LONGSIZE +1: + addi.d t0, t0, LONGSIZE + st.d zero, t0, 0 + bne t0, t1, 1b + + la t0, fw_arg0 + st.d a0, t0, 0 # firmware arguments + la t0, fw_arg1 + st.d a1, t0, 0 + + /* KSave3 used for percpu base, initialized as 0 */ + csrwr zero, PERCPU_BASE_KS + /* GPR21 used for percpu base (runtime), initialized as 0 */ + or u0, zero, zero + + la tp, init_thread_union + /* Set the SP after an empty pt_regs. */ + PTR_LI sp, (_THREAD_SIZE - 32 - PT_SIZE) + PTR_ADD sp, sp, tp + set_saved_sp sp, t0, t1 + PTR_ADDI sp, sp, -4 * SZREG # init stack pointer + + bl start_kernel + +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 + 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.abs t0, cpuboot_data + ld.d sp, t0, CPU_BOOT_STACK + ld.d tp, t0, CPU_BOOT_TINFO + + la.abs t0, 0f + jirl zero, t0, 0 +0: + bl start_secondary +SYM_CODE_END(smpboot_entry) + +#endif /* CONFIG_SMP */ + +SYM_ENTRY(kernel_entry_end, SYM_L_GLOBAL, SYM_A_NONE) |