diff options
Diffstat (limited to 'arch/sh/kernel/entry-common.S')
| -rw-r--r-- | arch/sh/kernel/entry-common.S | 119 |
1 files changed, 43 insertions, 76 deletions
diff --git a/arch/sh/kernel/entry-common.S b/arch/sh/kernel/entry-common.S index fc279aeb73a..ab4ebb856c2 100644 --- a/arch/sh/kernel/entry-common.S +++ b/arch/sh/kernel/entry-common.S @@ -54,79 +54,24 @@ # 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 */ -#ifdef CONFIG_SH_STANDARD_BIOS - bra debug_kernel_fw - nop -#endif -#endif /* CONFIG_SH_STANDARD_BIOS || CONFIG_SH_KGDB */ - - .align 2 -debug_trap: -#if defined(CONFIG_SH_STANDARD_BIOS) || defined(CONFIG_SH_KGDB) - mov r8, r0 - shlr2 r0 - cmp/eq #0x3f, r0 ! sh_bios() trap - bf 1f -#ifdef CONFIG_SH_KGDB - cmp/eq #0xff, r0 ! XXX: KGDB trap, fix for SH-2. - bf 1f -#endif - mov #OFF_SR, r0 - mov.l @(r0,r15), r0 ! get status register - shll r0 - shll r0 ! kernel space? - bt/s debug_kernel -1: -#endif - mov.l @r15, r0 ! Restore R0 value - mov.l 1f, r8 - jmp @r8 - nop .align 2 ENTRY(exception_error) ! #ifdef CONFIG_TRACE_IRQFLAGS - mov.l 3f, r0 + mov.l 2f, r0 jsr @r0 nop #endif sti - mov.l 2f, r0 + 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 -3: .long trace_hardirqs_on +2: .long trace_hardirqs_on #endif .align 2 @@ -331,16 +276,31 @@ __restore_all: 1: .long restore_all .align 2 -not_syscall_tra: - bra debug_trap - nop - - .align 2 syscall_badsys: ! Bad syscall number 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 + jmp @r8 + nop + + .align 2 +1: .long debug_trap_table /* * Syscall interface: @@ -348,17 +308,19 @@ syscall_badsys: ! Bad syscall number * 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" @@ -375,17 +337,22 @@ ret_from_fork: 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 not_syscall_tra + 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 |