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-rw-r--r--arch/h8300/kernel/entry.S393
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+/* -*- mode: asm -*-
+ *
+ * linux/arch/h8300/platform/h8300h/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,@SYMBOL_NAME(sw_usp)
+ mov.l @sp,er0 /* restore saved er0 */
+ orc #0x10,ccr /* switch kernel stack */
+ mov.l @SYMBOL_NAME(sw_ksp),sp
+ sub.l #(LRET-LORIG),sp /* allocate LORIG - LRET */
+ SAVEREGS
+ mov.l @SYMBOL_NAME(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 */
+ 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 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 #0x80,ccr
+ mov.l @SYMBOL_NAME(sw_usp),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,@SYMBOL_NAME(sw_ksp)
+ andc #0xef,ccr /* switch to user mode */
+ mov.l er0,sp
+ bra 8f
+7:
+ mov.l @sp+,er1
+ adds #4,sp
+ adds #2,sp
+8:
+ mov.l @sp+,er0
+ adds #4,sp /* remove the sw created LVEC */
+ rte
+ .endm
+
+.globl SYMBOL_NAME(system_call)
+.globl SYMBOL_NAME(ret_from_exception)
+.globl SYMBOL_NAME(ret_from_fork)
+.globl SYMBOL_NAME(ret_from_interrupt)
+.globl SYMBOL_NAME(interrupt_redirect_table)
+.globl SYMBOL_NAME(sw_ksp),SYMBOL_NAME(sw_usp)
+.globl SYMBOL_NAME(resume)
+.globl SYMBOL_NAME(interrupt_entry)
+.globl SYMBOL_NAME(trace_break)
+
+#if defined(CONFIG_ROMKERNEL)
+ .section .int_redirect,"ax"
+SYMBOL_NAME_LABEL(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 @SYMBOL_NAME(trace_break)
+ .long 0
+#endif
+
+ jsr @SYMBOL_NAME(interrupt_entry) /* NMI */
+ jmp @SYMBOL_NAME(system_call) /* TRAPA #0 (System call) */
+ .long 0
+ .long 0
+ jmp @SYMBOL_NAME(trace_break) /* TRAPA #3 (breakpoint) */
+ .rept INTERRUPTS-12
+ jsr @SYMBOL_NAME(interrupt_entry)
+ .endr
+#endif
+#if defined(CONFIG_RAMKERNEL)
+.globl SYMBOL_NAME(interrupt_redirect_table)
+ .section .bss
+SYMBOL_NAME_LABEL(interrupt_redirect_table)
+ .space 4
+#endif
+
+ .section .text
+ .align 2
+SYMBOL_NAME_LABEL(interrupt_entry)
+ SAVE_ALL
+ mov.l sp,er0
+ add.l #LVEC,er0
+ btst #4,r1l
+ bne 1f
+ /* user LVEC */
+ mov.l @SYMBOL_NAME(sw_usp),er0
+ adds #4,er0
+1:
+ mov.l @er0,er0 /* LVEC address */
+#if defined(CONFIG_ROMKERNEL)
+ sub.l #SYMBOL_NAME(interrupt_redirect_table),er0
+#endif
+#if defined(CONFIG_RAMKERNEL)
+ mov.l @SYMBOL_NAME(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 */
+ jsr @SYMBOL_NAME(do_IRQ)
+ jmp @SYMBOL_NAME(ret_from_interrupt)
+
+SYMBOL_NAME_LABEL(system_call)
+ subs #4,sp /* dummy LVEC */
+ SAVE_ALL
+ andc #0x7f,ccr
+ mov.l er0,er4
+
+ /* save top of frame */
+ mov.l sp,er0
+ jsr @SYMBOL_NAME(set_esp0)
+ mov.l sp,er2
+ and.w #0xe000,r2
+ mov.b @((TI_FLAGS+3-(TIF_SYSCALL_TRACE >> 3)):16,er2),r2l
+ btst #(TIF_SYSCALL_TRACE & 7),r2l
+ beq 1f
+ jsr @SYMBOL_NAME(do_syscall_trace)
+1:
+ cmp.l #NR_syscalls,er4
+ bcc badsys
+ SHLL2 er4
+ mov.l #SYMBOL_NAME(sys_call_table),er0
+ add.l er4,er0
+ mov.l @er0,er4
+ beq SYMBOL_NAME(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.b @((TI_FLAGS+3-(TIF_SYSCALL_TRACE >> 3)):16,er2),r2l
+ btst #(TIF_SYSCALL_TRACE & 7),r2l
+ beq 2f
+ jsr @SYMBOL_NAME(do_syscall_trace)
+2:
+#if defined(CONFIG_SYSCALL_PRINT)
+ jsr @SYMBOL_NAME(syscall_print)
+#endif
+ orc #0x80,ccr
+ bra resume_userspace
+
+badsys:
+ mov.l #-ENOSYS,er0
+ mov.l er0,@(LER0:16,sp)
+ bra resume_userspace
+
+#if !defined(CONFIG_PREEMPT)
+#define resume_kernel restore_all
+#endif
+
+SYMBOL_NAME_LABEL(ret_from_exception)
+#if defined(CONFIG_PREEMPT)
+ orc #0x80,ccr
+#endif
+SYMBOL_NAME_LABEL(ret_from_interrupt)
+ mov.b @(LCCR+1:16,sp),r0l
+ btst #4,r0l
+ bne resume_kernel:8 /* return from kernel */
+resume_userspace:
+ andc #0x7f,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 @SYMBOL_NAME(do_notify_resume)
+ bra restore_all:8
+work_resched:
+ mov.l sp,er0
+ jsr @SYMBOL_NAME(set_esp0)
+ jsr @SYMBOL_NAME(schedule)
+ bra resume_userspace:8
+restore_all:
+ RESTORE_ALL /* Does RTE */
+
+#if defined(CONFIG_PREEMPT)
+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 #PREEMPT_ACTIVE,er0
+ mov.l er0,@(TI_PRE_COUNT:16,er4)
+ andc #0x7f,ccr
+ mov.l sp,er0
+ jsr @SYMBOL_NAME(set_esp0)
+ jsr @SYMBOL_NAME(schedule)
+ orc #0x80,ccr
+ bra need_resched:8
+#endif
+
+SYMBOL_NAME_LABEL(ret_from_fork)
+ mov.l er2,er0
+ jsr @SYMBOL_NAME(schedule_tail)
+ jmp @SYMBOL_NAME(ret_from_exception)
+
+SYMBOL_NAME_LABEL(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 #0x80,ccr
+ mov.l @SYMBOL_NAME(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,@SYMBOL_NAME(sw_usp)
+ mov.l @(THREAD_KSP:16,er1),sp
+
+ /* restore status register */
+ mov.w @(THREAD_CCR+2:16,er1),r3
+
+ ldc r3l,ccr
+ rts
+
+SYMBOL_NAME_LABEL(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 @SYMBOL_NAME(set_esp0)
+ mov.l @SYMBOL_NAME(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 @SYMBOL_NAME(trace_trap)
+ jmp @SYMBOL_NAME(ret_from_exception)
+
+ .section .bss
+SYMBOL_NAME_LABEL(sw_ksp)
+ .space 4
+SYMBOL_NAME_LABEL(sw_usp)
+ .space 4
+
+ .end
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