diff --git a/arch/xtensa/include/asm/traps.h b/arch/xtensa/include/asm/traps.h index 28f33a8b7f5f..3ad151aee6af 100644 --- a/arch/xtensa/include/asm/traps.h +++ b/arch/xtensa/include/asm/traps.h @@ -65,4 +65,13 @@ static inline void spill_registers(void) #endif } +struct debug_table { + /* Pointer to debug exception handler */ + void (*debug_exception)(void); + /* Temporary register save area */ + unsigned long debug_save[1]; +}; + +void debug_exception(void); + #endif /* _XTENSA_TRAPS_H */ diff --git a/arch/xtensa/kernel/asm-offsets.c b/arch/xtensa/kernel/asm-offsets.c index b123ace3b67c..8fd46c6404ea 100644 --- a/arch/xtensa/kernel/asm-offsets.c +++ b/arch/xtensa/kernel/asm-offsets.c @@ -23,6 +23,7 @@ #include #include +#include #include int main(void) @@ -117,5 +118,10 @@ int main(void) DEFINE(_CLONE_UNTRACED, CLONE_UNTRACED); DEFINE(PG_ARCH_1, PG_arch_1); + /* struct debug_table */ + DEFINE(DT_DEBUG_EXCEPTION, + offsetof(struct debug_table, debug_exception)); + DEFINE(DT_DEBUG_SAVE, offsetof(struct debug_table, debug_save)); + return 0; } diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S index db5c1765b413..ab7904fd027f 100644 --- a/arch/xtensa/kernel/entry.S +++ b/arch/xtensa/kernel/entry.S @@ -789,36 +789,32 @@ ENTRY(debug_exception) movi a2, 1 << PS_EXCM_BIT or a2, a0, a2 - movi a0, debug_exception # restore a3, debug jump vector wsr a2, ps - xsr a0, SREG_EXCSAVE + XCHAL_DEBUGLEVEL /* Switch to kernel/user stack, restore jump vector, and save a0 */ bbsi.l a2, PS_UM_BIT, 2f # jump if user mode addi a2, a1, -16-PT_SIZE # assume kernel stack +3: + l32i a0, a3, DT_DEBUG_SAVE + s32i a1, a2, PT_AREG1 s32i a0, a2, PT_AREG0 movi a0, 0 - s32i a1, a2, PT_AREG1 s32i a0, a2, PT_DEPC # mark it as a regular exception + xsr a3, SREG_EXCSAVE + XCHAL_DEBUGLEVEL xsr a0, depc s32i a3, a2, PT_AREG3 s32i a0, a2, PT_AREG2 mov a1, a2 + + rsr a2, ps + bbsi.l a2, PS_UM_BIT, _user_exception j _kernel_exception 2: rsr a2, excsave1 l32i a2, a2, EXC_TABLE_KSTK # load kernel stack pointer - s32i a0, a2, PT_AREG0 - movi a0, 0 - s32i a1, a2, PT_AREG1 - s32i a0, a2, PT_DEPC - xsr a0, depc - s32i a3, a2, PT_AREG3 - s32i a0, a2, PT_AREG2 - mov a1, a2 - j _user_exception + j 3b /* Debug exception while in exception mode. */ 1: j 1b // FIXME!! diff --git a/arch/xtensa/kernel/head.S b/arch/xtensa/kernel/head.S index 05e1df943856..bc4f4bf05099 100644 --- a/arch/xtensa/kernel/head.S +++ b/arch/xtensa/kernel/head.S @@ -197,11 +197,6 @@ ENTRY(_startup) wsr a2, ps # (enable reg-windows; progmode stack) rsync - /* Set up EXCSAVE[DEBUGLEVEL] to point to the Debug Exception Handler.*/ - - movi a2, debug_exception - wsr a2, SREG_EXCSAVE + XCHAL_DEBUGLEVEL - #ifdef CONFIG_SMP /* * Notice that we assume with SMP that cores have PRID diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c index a8b8dae4139a..e4764f216a7a 100644 --- a/arch/xtensa/kernel/traps.c +++ b/arch/xtensa/kernel/traps.c @@ -157,6 +157,8 @@ COPROCESSOR(7), DEFINE_PER_CPU(unsigned long, exc_table[EXC_TABLE_SIZE/4]); +DEFINE_PER_CPU(struct debug_table, debug_table); + void die(const char*, struct pt_regs*, long); static inline void @@ -372,6 +374,15 @@ static void trap_init_excsave(void) __asm__ __volatile__("wsr %0, excsave1\n" : : "a" (excsave1)); } +static void trap_init_debug(void) +{ + unsigned long debugsave = (unsigned long)this_cpu_ptr(&debug_table); + + this_cpu_ptr(&debug_table)->debug_exception = debug_exception; + __asm__ __volatile__("wsr %0, excsave" __stringify(XCHAL_DEBUGLEVEL) + :: "a"(debugsave)); +} + /* * Initialize dispatch tables. * @@ -415,12 +426,14 @@ void __init trap_init(void) /* Initialize EXCSAVE_1 to hold the address of the exception table. */ trap_init_excsave(); + trap_init_debug(); } #ifdef CONFIG_SMP void secondary_trap_init(void) { trap_init_excsave(); + trap_init_debug(); } #endif diff --git a/arch/xtensa/kernel/vectors.S b/arch/xtensa/kernel/vectors.S index fc25318e75ad..332e9d635fb6 100644 --- a/arch/xtensa/kernel/vectors.S +++ b/arch/xtensa/kernel/vectors.S @@ -601,7 +601,9 @@ ENDPROC(window_overflow_restore_a0_fixup) ENTRY(_DebugInterruptVector) - xsr a0, SREG_EXCSAVE + XCHAL_DEBUGLEVEL + xsr a3, SREG_EXCSAVE + XCHAL_DEBUGLEVEL + s32i a0, a3, DT_DEBUG_SAVE + l32i a0, a3, DT_DEBUG_EXCEPTION jx a0 ENDPROC(_DebugInterruptVector)