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| /* SPDX-License-Identifier: GPL-2.0 */
| /*
| *
| * linux/arch/h8300/kernel/entry.S
| *
| * Yoshinori Sato <ysato@users.sourceforge.jp>
| * David McCullough <davidm@snapgear.com>
| *
| */
|
| /*
| * entry.S
| * include exception/interrupt gateway
| * system call entry
| */
|
| #include <linux/sys.h>
| #include <asm/unistd.h>
| #include <asm/setup.h>
| #include <asm/segment.h>
| #include <asm/linkage.h>
| #include <asm/asm-offsets.h>
| #include <asm/thread_info.h>
| #include <asm/errno.h>
|
| #if defined(CONFIG_CPU_H8300H)
| #define USERRET 8
| INTERRUPTS = 64
| .h8300h
| .macro SHLL2 reg
| shll.l \reg
| shll.l \reg
| .endm
| .macro SHLR2 reg
| shlr.l \reg
| shlr.l \reg
| .endm
| .macro SAVEREGS
| mov.l er0,@-sp
| mov.l er1,@-sp
| mov.l er2,@-sp
| mov.l er3,@-sp
| .endm
| .macro RESTOREREGS
| mov.l @sp+,er3
| mov.l @sp+,er2
| .endm
| .macro SAVEEXR
| .endm
| .macro RESTOREEXR
| .endm
| #endif
| #if defined(CONFIG_CPU_H8S)
| #define USERRET 10
| #define USEREXR 8
| INTERRUPTS = 128
| .h8300s
| .macro SHLL2 reg
| shll.l #2,\reg
| .endm
| .macro SHLR2 reg
| shlr.l #2,\reg
| .endm
| .macro SAVEREGS
| stm.l er0-er3,@-sp
| .endm
| .macro RESTOREREGS
| ldm.l @sp+,er2-er3
| .endm
| .macro SAVEEXR
| mov.w @(USEREXR:16,er0),r1
| mov.w r1,@(LEXR-LER3:16,sp) /* copy EXR */
| .endm
| .macro RESTOREEXR
| mov.w @(LEXR-LER1:16,sp),r1 /* restore EXR */
| mov.b r1l,r1h
| mov.w r1,@(USEREXR:16,er0)
| .endm
| #endif
|
|
| /* CPU context save/restore macros. */
|
| .macro SAVE_ALL
| mov.l er0,@-sp
| stc ccr,r0l /* check kernel mode */
| btst #4,r0l
| bne 5f
|
| /* user mode */
| mov.l sp,@_sw_usp
| mov.l @sp,er0 /* restore saved er0 */
| orc #0x10,ccr /* switch kernel stack */
| mov.l @_sw_ksp,sp
| sub.l #(LRET-LORIG),sp /* allocate LORIG - LRET */
| SAVEREGS
| mov.l @_sw_usp,er0
| mov.l @(USERRET:16,er0),er1 /* copy the RET addr */
| mov.l er1,@(LRET-LER3:16,sp)
| SAVEEXR
|
| mov.l @(LORIG-LER3:16,sp),er0
| mov.l er0,@(LER0-LER3:16,sp) /* copy ER0 */
| mov.w e1,r1 /* e1 highbyte = ccr */
| and #0xef,r1h /* mask mode? flag */
| bra 6f
| 5:
| /* kernel mode */
| mov.l @sp,er0 /* restore saved er0 */
| subs #2,sp /* set dummy ccr */
| subs #4,sp /* set dummp sp */
| SAVEREGS
| mov.w @(LRET-LER3:16,sp),r1 /* copy old ccr */
| 6:
| mov.b r1h,r1l
| mov.b #0,r1h
| mov.w r1,@(LCCR-LER3:16,sp) /* set ccr */
| mov.l @_sw_usp,er2
| mov.l er2,@(LSP-LER3:16,sp) /* set usp */
| mov.l er6,@-sp /* syscall arg #6 */
| mov.l er5,@-sp /* syscall arg #5 */
| mov.l er4,@-sp /* syscall arg #4 */
| .endm /* r1 = ccr */
|
| .macro RESTORE_ALL
| mov.l @sp+,er4
| mov.l @sp+,er5
| mov.l @sp+,er6
| RESTOREREGS
| mov.w @(LCCR-LER1:16,sp),r0 /* check kernel mode */
| btst #4,r0l
| bne 7f
|
| orc #0xc0,ccr
| mov.l @(LSP-LER1:16,sp),er0
| mov.l @(LER0-LER1:16,sp),er1 /* restore ER0 */
| mov.l er1,@er0
| RESTOREEXR
| mov.w @(LCCR-LER1:16,sp),r1 /* restore the RET addr */
| mov.b r1l,r1h
| mov.b @(LRET+1-LER1:16,sp),r1l
| mov.w r1,e1
| mov.w @(LRET+2-LER1:16,sp),r1
| mov.l er1,@(USERRET:16,er0)
|
| mov.l @sp+,er1
| add.l #(LRET-LER1),sp /* remove LORIG - LRET */
| mov.l sp,@_sw_ksp
| andc #0xef,ccr /* switch to user mode */
| mov.l er0,sp
| bra 8f
| 7:
| mov.l @sp+,er1
| add.l #10,sp
| 8:
| mov.l @sp+,er0
| adds #4,sp /* remove the sw created LVEC */
| rte
| .endm
|
| .globl _system_call
| .globl ret_from_exception
| .globl ret_from_fork
| .globl ret_from_kernel_thread
| .globl ret_from_interrupt
| .globl _interrupt_redirect_table
| .globl _sw_ksp,_sw_usp
| .globl _resume
| .globl _interrupt_entry
| .globl _trace_break
| .globl _nmi
|
| #if defined(CONFIG_ROMKERNEL)
| .section .int_redirect,"ax"
| _interrupt_redirect_table:
| #if defined(CONFIG_CPU_H8300H)
| .rept 7
| .long 0
| .endr
| #endif
| #if defined(CONFIG_CPU_H8S)
| .rept 5
| .long 0
| .endr
| jmp @_trace_break
| .long 0
| #endif
|
| jsr @_interrupt_entry /* NMI */
| jmp @_system_call /* TRAPA #0 (System call) */
| .long 0
| #if defined(CONFIG_KGDB)
| jmp @_kgdb_trap
| #else
| .long 0
| #endif
| jmp @_trace_break /* TRAPA #3 (breakpoint) */
| .rept INTERRUPTS-12
| jsr @_interrupt_entry
| .endr
| #endif
| #if defined(CONFIG_RAMKERNEL)
| .globl _interrupt_redirect_table
| .section .bss
| _interrupt_redirect_table:
| .space 4
| #endif
|
| .section .text
| .align 2
| _interrupt_entry:
| SAVE_ALL
| /* r1l is saved ccr */
| mov.l sp,er0
| add.l #LVEC,er0
| btst #4,r1l
| bne 1f
| /* user LVEC */
| mov.l @_sw_usp,er0
| adds #4,er0
| 1:
| mov.l @er0,er0 /* LVEC address */
| #if defined(CONFIG_ROMKERNEL)
| sub.l #_interrupt_redirect_table,er0
| #endif
| #if defined(CONFIG_RAMKERNEL)
| mov.l @_interrupt_redirect_table,er1
| sub.l er1,er0
| #endif
| SHLR2 er0
| dec.l #1,er0
| mov.l sp,er1
| subs #4,er1 /* adjust ret_pc */
| #if defined(CONFIG_CPU_H8S)
| orc #7,exr
| #endif
| jsr @do_IRQ
| jmp @ret_from_interrupt
|
| _system_call:
| subs #4,sp /* dummy LVEC */
| SAVE_ALL
| /* er0: syscall nr */
| andc #0xbf,ccr
| mov.l er0,er4
|
| /* save top of frame */
| mov.l sp,er0
| jsr @set_esp0
| andc #0x3f,ccr
| mov.l sp,er2
| and.w #0xe000,r2
| mov.l @(TI_FLAGS:16,er2),er2
| and.w #_TIF_WORK_SYSCALL_MASK,r2
| beq 1f
| mov.l sp,er0
| jsr @do_syscall_trace_enter
| 1:
| cmp.l #__NR_syscalls,er4
| bcc badsys
| SHLL2 er4
| mov.l #_sys_call_table,er0
| add.l er4,er0
| mov.l @er0,er4
| beq ret_from_exception:16
| mov.l @(LER1:16,sp),er0
| mov.l @(LER2:16,sp),er1
| mov.l @(LER3:16,sp),er2
| jsr @er4
| mov.l er0,@(LER0:16,sp) /* save the return value */
| mov.l sp,er2
| and.w #0xe000,r2
| mov.l @(TI_FLAGS:16,er2),er2
| and.w #_TIF_WORK_SYSCALL_MASK,r2
| beq 2f
| mov.l sp,er0
| jsr @do_syscall_trace_leave
| 2:
| orc #0xc0,ccr
| bra resume_userspace
|
| badsys:
| mov.l #-ENOSYS,er0
| mov.l er0,@(LER0:16,sp)
| bra resume_userspace
|
| #if !defined(CONFIG_PREEMPTION)
| #define resume_kernel restore_all
| #endif
|
| ret_from_exception:
| #if defined(CONFIG_PREEMPTION)
| orc #0xc0,ccr
| #endif
| ret_from_interrupt:
| mov.b @(LCCR+1:16,sp),r0l
| btst #4,r0l
| bne resume_kernel:16 /* return from kernel */
| resume_userspace:
| andc #0xbf,ccr
| mov.l sp,er4
| and.w #0xe000,r4 /* er4 <- current thread info */
| mov.l @(TI_FLAGS:16,er4),er1
| and.l #_TIF_WORK_MASK,er1
| beq restore_all:8
| work_pending:
| btst #TIF_NEED_RESCHED,r1l
| bne work_resched:8
| /* work notifysig */
| mov.l sp,er0
| subs #4,er0 /* er0: pt_regs */
| jsr @do_notify_resume
| bra resume_userspace:8
| work_resched:
| mov.l sp,er0
| jsr @set_esp0
| jsr @schedule
| bra resume_userspace:8
| restore_all:
| RESTORE_ALL /* Does RTE */
|
| #if defined(CONFIG_PREEMPTION)
| resume_kernel:
| mov.l @(TI_PRE_COUNT:16,er4),er0
| bne restore_all:8
| need_resched:
| mov.l @(TI_FLAGS:16,er4),er0
| btst #TIF_NEED_RESCHED,r0l
| beq restore_all:8
| mov.b @(LCCR+1:16,sp),r0l /* Interrupt Enabled? */
| bmi restore_all:8
| mov.l sp,er0
| jsr @set_esp0
| jsr @preempt_schedule_irq
| bra need_resched:8
| #endif
|
| ret_from_fork:
| mov.l er2,er0
| jsr @schedule_tail
| jmp @ret_from_exception
|
| ret_from_kernel_thread:
| mov.l er2,er0
| jsr @schedule_tail
| mov.l @(LER4:16,sp),er0
| mov.l @(LER5:16,sp),er1
| jsr @er1
| jmp @ret_from_exception
|
| _resume:
| /*
| * Beware - when entering resume, offset of tss is in d1,
| * prev (the current task) is in a0, next (the new task)
| * is in a1 and d2.b is non-zero if the mm structure is
| * shared between the tasks, so don't change these
| * registers until their contents are no longer needed.
| */
|
| /* save sr */
| sub.w r3,r3
| stc ccr,r3l
| mov.w r3,@(THREAD_CCR+2:16,er0)
|
| /* disable interrupts */
| orc #0xc0,ccr
| mov.l @_sw_usp,er3
| mov.l er3,@(THREAD_USP:16,er0)
| mov.l sp,@(THREAD_KSP:16,er0)
|
| /* Skip address space switching if they are the same. */
| /* FIXME: what did we hack out of here, this does nothing! */
|
| mov.l @(THREAD_USP:16,er1),er0
| mov.l er0,@_sw_usp
| mov.l @(THREAD_KSP:16,er1),sp
|
| /* restore status register */
| mov.w @(THREAD_CCR+2:16,er1),r3
|
| ldc r3l,ccr
| rts
|
| _trace_break:
| subs #4,sp
| SAVE_ALL
| sub.l er1,er1
| dec.l #1,er1
| mov.l er1,@(LORIG,sp)
| mov.l sp,er0
| jsr @set_esp0
| mov.l @_sw_usp,er0
| mov.l @er0,er1
| mov.w @(-2:16,er1),r2
| cmp.w #0x5730,r2
| beq 1f
| subs #2,er1
| mov.l er1,@er0
| 1:
| and.w #0xff,e1
| mov.l er1,er0
| jsr @trace_trap
| jmp @ret_from_exception
|
| _nmi:
| subs #4, sp
| mov.l er0, @-sp
| mov.l @_interrupt_redirect_table, er0
| add.l #8*4, er0
| mov.l er0, @(4,sp)
| mov.l @sp+, er0
| jmp @_interrupt_entry
|
| #if defined(CONFIG_KGDB)
| _kgdb_trap:
| subs #4,sp
| SAVE_ALL
| mov.l sp,er0
| add.l #LRET,er0
| mov.l er0,@(LSP,sp)
| jsr @set_esp0
| mov.l sp,er0
| subs #4,er0
| jsr @h8300_kgdb_trap
| jmp @ret_from_exception
| #endif
|
| .section .bss
| _sw_ksp:
| .space 4
| _sw_usp:
| .space 4
|
| .end
|
|
