-/* $Id: entry.S,v 1.37 2004/06/11 13:02:46 doyu Exp $
- *
- * linux/arch/sh/entry.S
- *
+/*
* Copyright (C) 1999, 2000, 2002 Niibe Yutaka
- * Copyright (C) 2003 Paul Mundt
+ * Copyright (C) 2003 - 2008 Paul Mundt
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
# define resume_kernel __restore_all
#endif
-#if defined(CONFIG_SH_STANDARD_BIOS) || defined(CONFIG_SH_KGDB)
-! Handle kernel debug if either kgdb (SW) or gdb-stub (FW) is present.
-! If both are configured, handle the debug traps (breakpoints) in SW,
-! but still allow BIOS traps to FW.
-
- .align 2
-debug_kernel:
-#if defined(CONFIG_SH_STANDARD_BIOS) && defined(CONFIG_SH_KGDB)
- /* Force BIOS call to FW (debug_trap put TRA in r8) */
- mov r8,r0
- shlr2 r0
- cmp/eq #0x3f,r0
- bt debug_kernel_fw
-#endif /* CONFIG_SH_STANDARD_BIOS && CONFIG_SH_KGDB */
-
-debug_enter:
-#if defined(CONFIG_SH_KGDB)
- /* Jump to kgdb, pass stacked regs as arg */
-debug_kernel_sw:
- mov.l 3f, r0
- jmp @r0
- mov r15, r4
- .align 2
-3: .long kgdb_handle_exception
-#endif /* CONFIG_SH_KGDB */
-
-#endif /* CONFIG_SH_STANDARD_BIOS || CONFIG_SH_KGDB */
-
-
- .align 2
-debug_trap:
-#if defined(CONFIG_SH_STANDARD_BIOS) || defined(CONFIG_SH_KGDB)
- mov #OFF_SR, r0
- mov.l @(r0,r15), r0 ! get status register
- shll r0
- shll r0 ! kernel space?
- bt/s debug_kernel
-#endif
- mov.l @r15, r0 ! Restore R0 value
- mov.l 1f, r8
- jmp @r8
- nop
.align 2
ENTRY(exception_error)
!
- sti
+#ifdef CONFIG_TRACE_IRQFLAGS
mov.l 2f, r0
+ jsr @r0
+ nop
+#endif
+ sti
+ mov.l 1f, r0
jmp @r0
nop
-!
.align 2
-1: .long break_point_trap_software
-2: .long do_exception_error
+1: .long do_exception_error
+#ifdef CONFIG_TRACE_IRQFLAGS
+2: .long trace_hardirqs_on
+#endif
.align 2
ret_from_exception:
preempt_stop()
+#ifdef CONFIG_TRACE_IRQFLAGS
+ mov.l 4f, r0
+ jsr @r0
+ nop
+#endif
ENTRY(ret_from_irq)
!
mov #OFF_SR, r0
bra resume_userspace
nop
ENTRY(resume_kernel)
+ cli
mov.l @(TI_PRE_COUNT,r8), r0 ! current_thread_info->preempt_count
tst r0, r0
bf noresched
and #0xf0, r0 ! interrupts off (exception path)?
cmp/eq #0xf0, r0
bt noresched
-
- mov.l 1f, r0
- mov.l r0, @(TI_PRE_COUNT,r8)
-
- sti
- mov.l 2f, r0
- jsr @r0
+ mov.l 3f, r0
+ jsr @r0 ! call preempt_schedule_irq
nop
- mov #0, r0
- mov.l r0, @(TI_PRE_COUNT,r8)
- cli
-
bra need_resched
nop
+
noresched:
bra __restore_all
nop
.align 2
1: .long PREEMPT_ACTIVE
2: .long schedule
+3: .long preempt_schedule_irq
#endif
ENTRY(resume_userspace)
! r8: current_thread_info
cli
+#ifdef CONFIG_TRACE_IRQFLAGS
+ mov.l 5f, r0
+ jsr @r0
+ nop
+#endif
mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
tst #_TIF_WORK_MASK, r0
bt/s __restore_all
jmp @r1
lds r0, pr
work_resched:
-#ifndef CONFIG_PREEMPT
- ! gUSA handling
- mov.l @(OFF_SP,r15), r0 ! get user space stack pointer
- mov r0, r1
- shll r0
- bf/s 1f
- shll r0
- bf/s 1f
- mov #OFF_PC, r0
- ! SP >= 0xc0000000 : gUSA mark
- mov.l @(r0,r15), r2 ! get user space PC (program counter)
- mov.l @(OFF_R0,r15), r3 ! end point
- cmp/hs r3, r2 ! r2 >= r3?
- bt 1f
- add r3, r1 ! rewind point #2
- mov.l r1, @(r0,r15) ! reset PC to rewind point #2
- !
-1:
-#endif
mov.l 1f, r1
jsr @r1 ! schedule
nop
cli
+#ifdef CONFIG_TRACE_IRQFLAGS
+ mov.l 5f, r0
+ jsr @r0
+ nop
+#endif
!
mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
tst #_TIF_WORK_MASK, r0
.align 2
1: .long schedule
2: .long do_notify_resume
-3: .long restore_all
+3: .long resume_userspace
+#ifdef CONFIG_TRACE_IRQFLAGS
+4: .long trace_hardirqs_on
+5: .long trace_hardirqs_off
+#endif
.align 2
syscall_exit_work:
! r0: current_thread_info->flags
! r8: current_thread_info
- tst #_TIF_SYSCALL_TRACE, r0
+ tst #_TIF_WORK_SYSCALL_MASK, r0
bt/s work_pending
tst #_TIF_NEED_RESCHED, r0
+#ifdef CONFIG_TRACE_IRQFLAGS
+ mov.l 5f, r0
+ jsr @r0
+ nop
+#endif
sti
- ! XXX setup arguments...
- mov.l 4f, r0 ! do_syscall_trace
+ mov r15, r4
+ mov.l 8f, r0 ! do_syscall_trace_leave
jsr @r0
nop
bra resume_userspace
.align 2
syscall_trace_entry:
! Yes it is traced.
- ! XXX setup arguments...
- mov.l 4f, r11 ! Call do_syscall_trace which notifies
+ mov r15, r4
+ mov.l 7f, r11 ! Call do_syscall_trace_enter which notifies
jsr @r11 ! superior (will chomp R[0-7])
nop
+ mov.l r0, @(OFF_R0,r15) ! Save return value
! Reload R0-R4 from kernel stack, where the
! parent may have modified them using
! ptrace(POKEUSR). (Note that R0-R2 are
mov.l @(OFF_R6,r15), r6
mov.l @(OFF_R7,r15), r7 ! arg3
mov.l @(OFF_R3,r15), r3 ! syscall_nr
- ! Arrange for do_syscall_trace to be called
- ! again as the system call returns.
+ !
mov.l 2f, r10 ! Number of syscalls
cmp/hs r10, r3
bf syscall_call
mov.l r0, @(OFF_R0,r15) ! Return value
__restore_all:
- mov.l 1f,r0
+ mov.l 1f, r0
jmp @r0
nop
.align 2
1: .long restore_all
+ .align 2
+syscall_badsys: ! Bad syscall number
+ get_current_thread_info r8, r0
+ mov #-ENOSYS, r0
+ bra resume_userspace
+ mov.l r0, @(OFF_R0,r15) ! Return value
+
+/*
+ * The main debug trap handler.
+ *
+ * r8=TRA (not the trap number!)
+ *
+ * Note: This assumes that the trapa value is left in its original
+ * form (without the shlr2 shift) so the calculation for the jump
+ * call table offset remains a simple in place mask.
+ */
+debug_trap:
+ mov r8, r0
+ and #(0xf << 2), r0
+ mov.l 1f, r8
+ add r0, r8
+ mov.l @r8, r8
+ jsr @r8
+ nop
+ bra __restore_all
+ nop
+
+ .align 2
+1: .long debug_trap_table
+
/*
* Syscall interface:
*
* Syscall #: R3
* Arguments #0 to #3: R4--R7
* Arguments #4 to #6: R0, R1, R2
- * TRA: (number of arguments + 0x10) x 4
+ * TRA: (number of arguments + ABI revision) x 4
*
* This code also handles delegating other traps to the BIOS/gdb stub
* according to:
*
* Trap number
- * (TRA>>2) Purpose
- * -------- -------
- * 0x0-0xf old syscall ABI
- * 0x10-0x1f new syscall ABI
- * 0x20-0xff delegated through debug_trap to BIOS/gdb stub.
+ * (TRA>>2) Purpose
+ * -------- -------
+ * 0x00-0x0f original SH-3/4 syscall ABI (not in general use).
+ * 0x10-0x1f general SH-3/4 syscall ABI.
+ * 0x20-0x2f syscall ABI for SH-2 parts.
+ * 0x30-0x3f debug traps used by the kernel.
+ * 0x40-0xff Not supported by all parts, so left unhandled.
*
* Note: When we're first called, the TRA value must be shifted
* right 2 bits in order to get the value that was used as the "trapa"
nop
.align 2
1: .long schedule_tail
- !
+
+/*
+ * The poorly named main trapa decode and dispatch routine, for
+ * system calls and debug traps through their respective jump tables.
+ */
ENTRY(system_call)
#if !defined(CONFIG_CPU_SH2)
mov.l 1f, r9
mov.l @r9, r8 ! Read from TRA (Trap Address) Register
#endif
- !
- ! Is the trap argument >= 0x20? (TRA will be >= 0x80)
- mov #0x7f, r9
+ /*
+ * Check the trap type
+ */
+ mov #((0x20 << 2) - 1), r9
cmp/hi r9, r8
- bt/s 0f
+ bt/s debug_trap ! it's a debug trap..
mov #OFF_TRA, r9
add r15, r9
- !
mov.l r8, @r9 ! set TRA value to tra
- sti
- ! Call the system call handler through the table.
- ! First check for bad syscall number
- mov r3, r9
- mov.l 2f, r8 ! Number of syscalls
- cmp/hs r8, r9
- get_current_thread_info r8, r10
- bf good_system_call
-syscall_badsys: ! Bad syscall number
- mov #-ENOSYS, r0
- bra resume_userspace
- mov.l r0, @(OFF_R0,r15) ! Return value
- !
-0:
- bra debug_trap
+#ifdef CONFIG_TRACE_IRQFLAGS
+ mov.l 5f, r10
+ jsr @r10
nop
+#endif
+ sti
+
!
-good_system_call: ! Good syscall number
+ get_current_thread_info r8, r10
mov.l @(TI_FLAGS,r8), r8
- mov #_TIF_SYSCALL_TRACE, r10
+ mov #_TIF_WORK_SYSCALL_MASK, r10
tst r10, r8
bf syscall_trace_entry
!
+ mov.l 2f, r8 ! Number of syscalls
+ cmp/hs r8, r3
+ bt syscall_badsys
+ !
syscall_call:
- shll2 r9 ! x4
+ shll2 r3 ! x4
mov.l 3f, r8 ! Load the address of sys_call_table
- add r8, r9
- mov.l @r9, r8
+ add r8, r3
+ mov.l @r3, r8
jsr @r8 ! jump to specific syscall handler
nop
mov.l @(OFF_R0,r15), r12 ! save r0
!
syscall_exit:
cli
+#ifdef CONFIG_TRACE_IRQFLAGS
+ mov.l 6f, r0
+ jsr @r0
+ nop
+#endif
!
get_current_thread_info r8, r0
mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
#endif
2: .long NR_syscalls
3: .long sys_call_table
-4: .long do_syscall_trace
+#ifdef CONFIG_TRACE_IRQFLAGS
+5: .long trace_hardirqs_on
+6: .long trace_hardirqs_off
+#endif
+7: .long do_syscall_trace_enter
+8: .long do_syscall_trace_leave
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff