diff options
Diffstat (limited to 'arch/csky/kernel/entry.S')
| -rw-r--r-- | arch/csky/kernel/entry.S | 396 |
1 files changed, 396 insertions, 0 deletions
diff --git a/arch/csky/kernel/entry.S b/arch/csky/kernel/entry.S new file mode 100644 index 000000000000..79f92b8606c8 --- /dev/null +++ b/arch/csky/kernel/entry.S @@ -0,0 +1,396 @@ +/* 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/setup.h> +#include <asm/page.h> +#include <asm/thread_info.h> + +#define PTE_INDX_MSK 0xffc +#define PTE_INDX_SHIFT 10 +#define _PGDIR_SHIFT 22 + +.macro tlbop_begin name, val0, val1, val2 +ENTRY(csky_\name) + mtcr a3, ss2 + mtcr r6, ss3 + mtcr a2, ss4 + + RD_PGDR r6 + RD_MEH a3 +#ifdef CONFIG_CPU_HAS_TLBI + tlbi.vaas a3 + sync.is + + btsti a3, 31 + bf 1f + RD_PGDR_K r6 +1: +#else + bgeni a2, 31 + WR_MCIR a2 + bgeni a2, 25 + WR_MCIR a2 +#endif + bclri r6, 0 + lrw a2, PHYS_OFFSET + subu r6, a2 + bseti r6, 31 + + mov a2, a3 + lsri a2, _PGDIR_SHIFT + lsli a2, 2 + addu r6, a2 + ldw r6, (r6) + + lrw a2, PHYS_OFFSET + subu r6, a2 + bseti r6, 31 + + lsri a3, PTE_INDX_SHIFT + lrw a2, PTE_INDX_MSK + and a3, a2 + addu r6, a3 + ldw a3, (r6) + + movi a2, (_PAGE_PRESENT | \val0) + and a3, a2 + cmpne a3, a2 + bt \name + + /* First read/write the page, just update the flags */ + ldw a3, (r6) + bgeni a2, PAGE_VALID_BIT + bseti a2, PAGE_ACCESSED_BIT + bseti a2, \val1 + bseti a2, \val2 + or a3, a2 + stw a3, (r6) + + /* Some cpu tlb-hardrefill bypass the cache */ +#ifdef CONFIG_CPU_NEED_TLBSYNC + movi a2, 0x22 + bseti a2, 6 + mtcr r6, cr22 + mtcr a2, cr17 + sync +#endif + + mfcr a3, ss2 + mfcr r6, ss3 + mfcr a2, ss4 + rte +\name: + mfcr a3, ss2 + mfcr r6, ss3 + mfcr a2, ss4 + SAVE_ALL EPC_KEEP +.endm +.macro tlbop_end is_write + RD_MEH a2 + psrset ee, ie + mov a0, sp + movi a1, \is_write + jbsr do_page_fault + movi r11_sig, 0 /* r11 = 0, Not a syscall. */ + jmpi ret_from_exception +.endm + +.text + +tlbop_begin tlbinvalidl, _PAGE_READ, PAGE_VALID_BIT, PAGE_ACCESSED_BIT +tlbop_end 0 + +tlbop_begin tlbinvalids, _PAGE_WRITE, PAGE_DIRTY_BIT, PAGE_MODIFIED_BIT +tlbop_end 1 + +tlbop_begin tlbmodified, _PAGE_WRITE, PAGE_DIRTY_BIT, PAGE_MODIFIED_BIT +#ifndef CONFIG_CPU_HAS_LDSTEX +jbsr csky_cmpxchg_fixup +#endif +tlbop_end 1 + +ENTRY(csky_systemcall) + SAVE_ALL EPC_INCREASE + + psrset ee, ie + + /* Stack frame for syscall, origin call set_esp0 */ + mov r12, sp + + bmaski r11, 13 + andn r12, r11 + bgeni r11, 9 + addi r11, 32 + addu r12, r11 + st sp, (r12, 0) + + lrw r11, __NR_syscalls + cmphs syscallid, r11 /* Check nr of syscall */ + bt ret_from_exception + + lrw r13, sys_call_table + ixw r13, syscallid + ldw r11, (r13) + cmpnei r11, 0 + bf ret_from_exception + + mov r9, sp + bmaski r10, THREAD_SHIFT + andn r9, r10 + ldw r8, (r9, TINFO_FLAGS) + btsti r8, TIF_SYSCALL_TRACE + bt 1f +#if defined(__CSKYABIV2__) + subi sp, 8 + stw r5, (sp, 0x4) + stw r4, (sp, 0x0) + jsr r11 /* Do system call */ + addi sp, 8 +#else + jsr r11 +#endif + stw a0, (sp, LSAVE_A0) /* Save return value */ + jmpi ret_from_exception + +1: + movi a0, 0 /* enter system call */ + mov a1, sp /* sp = pt_regs pointer */ + jbsr syscall_trace + /* 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 + stw r5, (sp, 0x4) + stw r4, (sp, 0x0) +#else + ldw r6, (sp, LSAVE_A4) + ldw r7, (sp, LSAVE_A5) +#endif + jsr r11 /* Do system call */ +#if defined(__CSKYABIV2__) + addi sp, 8 +#endif + stw a0, (sp, LSAVE_A0) /* Save return value */ + + movi a0, 1 /* leave system call */ + mov a1, sp /* sp = pt_regs pointer */ + jbsr syscall_trace + +syscall_exit_work: + ld syscallid, (sp, LSAVE_PSR) + btsti syscallid, 31 + bt 2f + + jmpi resume_userspace + +2: RESTORE_ALL + +ENTRY(ret_from_kernel_thread) + jbsr schedule_tail + mov a0, r8 + jsr r9 + jbsr ret_from_exception + +ENTRY(ret_from_fork) + jbsr schedule_tail + mov r9, sp + bmaski r10, THREAD_SHIFT + andn r9, r10 + ldw r8, (r9, TINFO_FLAGS) + movi r11_sig, 1 + btsti r8, TIF_SYSCALL_TRACE + bf 3f + movi a0, 1 + mov a1, sp /* sp = pt_regs pointer */ + jbsr syscall_trace +3: + jbsr ret_from_exception + +ret_from_exception: + ld syscallid, (sp, LSAVE_PSR) + btsti syscallid, 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 + +resume_userspace: + ldw r8, (r9, TINFO_FLAGS) + andi r8, (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED) + cmpnei r8, 0 + bt exit_work +1: RESTORE_ALL + +exit_work: + mov a0, sp /* Stack address is arg[0] */ + jbsr set_esp0 /* Call C level */ + btsti r8, TIF_NEED_RESCHED + bt work_resched + /* If thread_info->flag is empty, RESTORE_ALL */ + cmpnei r8, 0 + bf 1b + mov a1, sp + mov a0, r8 + mov a2, r11_sig /* syscall? */ + btsti r8, TIF_SIGPENDING /* delivering a signal? */ + /* prevent further restarts(set r11 = 0) */ + clrt r11_sig + jbsr do_notify_resume /* do signals */ + br resume_userspace + +work_resched: + lrw syscallid, ret_from_exception + mov r15, syscallid /* Return address in link */ + jmpi schedule + +ENTRY(sys_rt_sigreturn) + movi r11_sig, 0 + jmpi do_rt_sigreturn + +ENTRY(csky_trap) + SAVE_ALL EPC_KEEP + psrset ee + movi r11_sig, 0 /* r11 = 0, Not a syscall. */ + 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 + + /* increase epc for continue */ + mfcr a0, epc + INCTRAP a0 + 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 EPC_KEEP + psrset ee + movi r11_sig, 0 /* r11 = 0, Not a syscall. */ + +#ifdef CONFIG_PREEMPT + mov r9, sp /* Get current stack pointer */ + bmaski r10, THREAD_SHIFT + andn r9, r10 /* Get thread_info */ + + /* + * Get task_struct->stack.preempt_count for current, + * and increase 1. + */ + ldw r8, (r9, TINFO_PREEMPT) + addi r8, 1 + stw r8, (r9, TINFO_PREEMPT) +#endif + + mov a0, sp + jbsr csky_do_IRQ + +#ifdef CONFIG_PREEMPT + subi r8, 1 + stw r8, (r9, TINFO_PREEMPT) + cmpnei r8, 0 + bt 2f + ldw r8, (r9, TINFO_FLAGS) + btsti r8, TIF_NEED_RESCHED + bf 2f +1: + jbsr preempt_schedule_irq /* irq en/disable is done inside */ + ldw r7, (r9, TINFO_FLAGS) /* get new tasks TI_FLAGS */ + btsti r7, TIF_NEED_RESCHED + bt 1b /* go again */ +#endif +2: + 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 + + mfcr a2, psr /* Save PSR value */ + stw a2, (a3, THREAD_SR) /* Save PSR in task struct */ + bclri a2, 6 /* Disable interrupts */ + mtcr a2, psr + + SAVE_SWITCH_STACK + + stw sp, (a3, THREAD_KSP) + +#ifdef CONFIG_CPU_HAS_HILO + lrw r10, THREAD_DSPHI + add r10, a3 + mfhi r6 + mflo r7 + stw r6, (r10, 0) /* THREAD_DSPHI */ + stw r7, (r10, 4) /* THREAD_DSPLO */ + mfcr r6, cr14 + stw r6, (r10, 8) /* THREAD_DSPCSR */ +#endif + + /* Set up next process to run */ + lrw a3, TASK_THREAD + addu a3, a1 + + ldw sp, (a3, THREAD_KSP) /* Set next kernel sp */ + +#ifdef CONFIG_CPU_HAS_HILO + lrw r10, THREAD_DSPHI + add r10, a3 + ldw r6, (r10, 8) /* THREAD_DSPCSR */ + mtcr r6, cr14 + ldw r6, (r10, 0) /* THREAD_DSPHI */ + ldw r7, (r10, 4) /* THREAD_DSPLO */ + mthi r6 + mtlo r7 +#endif + + ldw a2, (a3, THREAD_SR) /* Set next PSR */ + mtcr a2, psr + +#if defined(__CSKYABIV2__) + addi r7, a1, TASK_THREAD_INFO + ldw tls, (r7, TINFO_TP_VALUE) +#endif + + RESTORE_SWITCH_STACK + + rts +ENDPROC(__switch_to) |