diff options
Diffstat (limited to 'arch/csky/kernel/entry.S')
| -rw-r--r-- | arch/csky/kernel/entry.S | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/arch/csky/kernel/entry.S b/arch/csky/kernel/entry.S new file mode 100644 index 000000000..c68cdcc76 --- /dev/null +++ b/arch/csky/kernel/entry.S @@ -0,0 +1,274 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. + +#include <linux/linkage.h> +#include <abi/entry.h> +#include <abi/pgtable-bits.h> +#include <asm/errno.h> +#include <asm/setup.h> +#include <asm/unistd.h> +#include <asm/asm-offsets.h> +#include <linux/threads.h> +#include <asm/page.h> +#include <asm/thread_info.h> + +.macro zero_fp +#ifdef CONFIG_STACKTRACE + movi r8, 0 +#endif +.endm + +.macro context_tracking +#ifdef CONFIG_CONTEXT_TRACKING_USER + mfcr a0, epsr + btsti a0, 31 + bt 1f + jbsr user_exit_callable + ldw a0, (sp, LSAVE_A0) + ldw a1, (sp, LSAVE_A1) + ldw a2, (sp, LSAVE_A2) + ldw a3, (sp, LSAVE_A3) +#if defined(__CSKYABIV1__) + ldw r6, (sp, LSAVE_A4) + ldw r7, (sp, LSAVE_A5) +#endif +1: +#endif +.endm + +.text +ENTRY(csky_pagefault) + SAVE_ALL 0 + zero_fp + context_tracking + psrset ee + mov a0, sp + jbsr do_page_fault + jmpi ret_from_exception + +ENTRY(csky_systemcall) + SAVE_ALL TRAP0_SIZE + zero_fp + context_tracking + psrset ee, ie + + lrw r9, __NR_syscalls + cmphs syscallid, r9 /* Check nr of syscall */ + bt ret_from_exception + + lrw r9, sys_call_table + ixw r9, syscallid + ldw syscallid, (r9) + cmpnei syscallid, 0 + bf ret_from_exception + + mov r9, sp + bmaski r10, THREAD_SHIFT + andn r9, r10 + ldw r10, (r9, TINFO_FLAGS) + lrw r9, _TIF_SYSCALL_WORK + and r10, r9 + cmpnei r10, 0 + bt csky_syscall_trace +#if defined(__CSKYABIV2__) + subi sp, 8 + stw r5, (sp, 0x4) + stw r4, (sp, 0x0) + jsr syscallid /* Do system call */ + addi sp, 8 +#else + jsr syscallid +#endif + stw a0, (sp, LSAVE_A0) /* Save return value */ + jmpi ret_from_exception + +csky_syscall_trace: + mov a0, sp /* sp = pt_regs pointer */ + jbsr syscall_trace_enter + cmpnei a0, 0 + bt 1f + /* Prepare args before do system call */ + ldw a0, (sp, LSAVE_A0) + ldw a1, (sp, LSAVE_A1) + ldw a2, (sp, LSAVE_A2) + ldw a3, (sp, LSAVE_A3) +#if defined(__CSKYABIV2__) + subi sp, 8 + ldw r9, (sp, LSAVE_A4) + stw r9, (sp, 0x0) + ldw r9, (sp, LSAVE_A5) + stw r9, (sp, 0x4) + jsr syscallid /* Do system call */ + addi sp, 8 +#else + ldw r6, (sp, LSAVE_A4) + ldw r7, (sp, LSAVE_A5) + jsr syscallid /* Do system call */ +#endif + stw a0, (sp, LSAVE_A0) /* Save return value */ + +1: + mov a0, sp /* right now, sp --> pt_regs */ + jbsr syscall_trace_exit + br ret_from_exception + +ENTRY(ret_from_kernel_thread) + jbsr schedule_tail + mov a0, r10 + jsr r9 + jbsr ret_from_exception + +ENTRY(ret_from_fork) + jbsr schedule_tail + mov r9, sp + bmaski r10, THREAD_SHIFT + andn r9, r10 + ldw r10, (r9, TINFO_FLAGS) + lrw r9, _TIF_SYSCALL_WORK + and r10, r9 + cmpnei r10, 0 + bf ret_from_exception + mov a0, sp /* sp = pt_regs pointer */ + jbsr syscall_trace_exit + +ret_from_exception: + psrclr ie + ld r9, (sp, LSAVE_PSR) + btsti r9, 31 + + bt 1f + /* + * Load address of current->thread_info, Then get address of task_struct + * Get task_needreshed in task_struct + */ + mov r9, sp + bmaski r10, THREAD_SHIFT + andn r9, r10 + + ldw r10, (r9, TINFO_FLAGS) + lrw r9, _TIF_WORK_MASK + and r10, r9 + cmpnei r10, 0 + bt exit_work +#ifdef CONFIG_CONTEXT_TRACKING_USER + jbsr user_enter_callable +#endif +1: +#ifdef CONFIG_PREEMPTION + mov r9, sp + bmaski r10, THREAD_SHIFT + andn r9, r10 + + ldw r10, (r9, TINFO_PREEMPT) + cmpnei r10, 0 + bt 2f + jbsr preempt_schedule_irq /* irq en/disable is done inside */ +2: +#endif + +#ifdef CONFIG_TRACE_IRQFLAGS + ld r10, (sp, LSAVE_PSR) + btsti r10, 6 + bf 2f + jbsr trace_hardirqs_on +2: +#endif + RESTORE_ALL + +exit_work: + lrw r9, ret_from_exception + mov lr, r9 + + btsti r10, TIF_NEED_RESCHED + bt work_resched + + psrset ie + mov a0, sp + mov a1, r10 + jmpi do_notify_resume + +work_resched: + jmpi schedule + +ENTRY(csky_trap) + SAVE_ALL 0 + zero_fp + context_tracking + psrset ee + mov a0, sp /* Push Stack pointer arg */ + jbsr trap_c /* Call C-level trap handler */ + jmpi ret_from_exception + +/* + * Prototype from libc for abiv1: + * register unsigned int __result asm("a0"); + * asm( "trap 3" :"=r"(__result)::); + */ +ENTRY(csky_get_tls) + USPTOKSP + + RD_MEH a0 + WR_MEH a0 + + /* increase epc for continue */ + mfcr a0, epc + addi a0, TRAP0_SIZE + mtcr a0, epc + + /* get current task thread_info with kernel 8K stack */ + bmaski a0, THREAD_SHIFT + not a0 + subi sp, 1 + and a0, sp + addi sp, 1 + + /* get tls */ + ldw a0, (a0, TINFO_TP_VALUE) + + KSPTOUSP + rte + +ENTRY(csky_irq) + SAVE_ALL 0 + zero_fp + context_tracking + psrset ee + +#ifdef CONFIG_TRACE_IRQFLAGS + jbsr trace_hardirqs_off +#endif + + + mov a0, sp + jbsr generic_handle_arch_irq + + jmpi ret_from_exception + +/* + * a0 = prev task_struct * + * a1 = next task_struct * + * a0 = return next + */ +ENTRY(__switch_to) + lrw a3, TASK_THREAD + addu a3, a0 + + SAVE_SWITCH_STACK + + stw sp, (a3, THREAD_KSP) + + /* Set up next process to run */ + lrw a3, TASK_THREAD + addu a3, a1 + + ldw sp, (a3, THREAD_KSP) /* Set next kernel sp */ + +#if defined(__CSKYABIV2__) + addi a3, a1, TASK_THREAD_INFO + ldw tls, (a3, TINFO_TP_VALUE) +#endif + + RESTORE_SWITCH_STACK + + rts +ENDPROC(__switch_to) |