/* 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	zero_fp#ifdef CONFIG_STACKTRACE	movi	r8, 0#endif.endm .macro	context_tracking#ifdef CONFIG_CONTEXT_TRACKING	mfcr	a0, epsr	btsti	a0, 31	bt	1f	jbsr	context_tracking_user_exit	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)#endif1:#endif.endm .macro tlbop_begin name, val0, val1, val2ENTRY(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 r61:#else	bgeni	a2, 31	WR_MCIR	a2	bgeni	a2, 25	WR_MCIR	a2#endif	bclri   r6, 0	lrw	a2, va_pa_offset	ld.w	a2, (a2, 0)	subu	r6, a2	bseti	r6, 31 	mov     a2, a3	lsri    a2, _PGDIR_SHIFT	lsli    a2, 2	addu    r6, a2	ldw     r6, (r6) 	lrw	a2, va_pa_offset	ld.w	a2, (a2, 0)	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 0.endm.macro tlbop_end is_write	zero_fp	context_tracking	RD_MEH	a2	psrset  ee, ie	mov     a0, sp	movi    a1, \is_write	jbsr    do_page_fault	jmpi    ret_from_exception.endm .text tlbop_begin tlbinvalidl, _PAGE_READ, PAGE_VALID_BIT, PAGE_ACCESSED_BITtlbop_end 0 tlbop_begin tlbinvalids, _PAGE_WRITE, PAGE_DIRTY_BIT, PAGE_MODIFIED_BITtlbop_end 1 tlbop_begin tlbmodified, _PAGE_WRITE, PAGE_DIRTY_BIT, PAGE_MODIFIED_BIT#ifndef CONFIG_CPU_HAS_LDSTEXjbsr csky_cmpxchg_fixup#endiftlbop_end 1 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      1f 	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 */1:#ifdef CONFIG_DEBUG_RSEQ	mov	a0, sp	jbsr	rseq_syscall#endif	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:#ifdef CONFIG_DEBUG_RSEQ	mov	a0, sp	jbsr	rseq_syscall#endif	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	jbsr	context_tracking_user_enter#endif1:#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_on2:#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 	/* 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	csky_do_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 	rtsENDPROC(__switch_to)