diff options
Diffstat (limited to 'arch/mn10300/kernel/switch_to.S')
| -rw-r--r-- | arch/mn10300/kernel/switch_to.S | 111 |
1 files changed, 110 insertions, 1 deletions
diff --git a/arch/mn10300/kernel/switch_to.S b/arch/mn10300/kernel/switch_to.S index 9074d0f..de3e74f 100644 --- a/arch/mn10300/kernel/switch_to.S +++ b/arch/mn10300/kernel/switch_to.S @@ -39,11 +39,17 @@ ENTRY(__switch_to) # save prev context mov __switch_back,d0 - mov d0,(THREAD_PC,a0) mov sp,a2 mov a2,(THREAD_SP,a0) mov a3,(THREAD_A3,a0) +#ifdef CONFIG_KGDB + btst 0xff,(kgdb_single_step) + bne __switch_to__lift_sstep_bp +__switch_to__continue: +#endif + mov d0,(THREAD_PC,a0) + mov (THREAD_A3,a1),a3 mov (THREAD_SP,a1),a2 @@ -68,3 +74,106 @@ ENTRY(__switch_to) __switch_back: and ~EPSW_NMID,epsw ret [d2,d3,a2,a3,exreg1],32 + +#ifdef CONFIG_KGDB +############################################################################### +# +# Lift the single-step breakpoints when the task being traced is switched out +# A0 = prev +# A1 = next +# +############################################################################### +__switch_to__lift_sstep_bp: + add -12,sp + mov a0,e4 + mov a1,e5 + + # Clear the single-step flag to prevent us coming this way until we get + # switched back in + bclr 0xff,(kgdb_single_step) + + # Remove first breakpoint + mov (kgdb_sstep_bp_addr),a2 + cmp 0,a2 + beq 1f + movbu (kgdb_sstep_bp),d0 + movbu d0,(a2) +#if defined(CONFIG_MN10300_CACHE_FLUSH_ICACHE) || defined(CONFIG_MN10300_CACHE_INV_ICACHE) + mov a2,d0 + mov a2,d1 + add 1,d1 + calls flush_icache_range +#endif +1: + + # Remove second breakpoint + mov (kgdb_sstep_bp_addr+4),a2 + cmp 0,a2 + beq 2f + movbu (kgdb_sstep_bp+1),d0 + movbu d0,(a2) +#if defined(CONFIG_MN10300_CACHE_FLUSH_ICACHE) || defined(CONFIG_MN10300_CACHE_INV_ICACHE) + mov a2,d0 + mov a2,d1 + add 1,d1 + calls flush_icache_range +#endif +2: + + # Change the resumption address and return + mov __switch_back__reinstall_sstep_bp,d0 + mov e4,a0 + mov e5,a1 + add 12,sp + bra __switch_to__continue + +############################################################################### +# +# Reinstall the single-step breakpoints when the task being traced is switched +# back in (A1 points to the new thread_struct). +# +############################################################################### +__switch_back__reinstall_sstep_bp: + add -12,sp + mov a0,e4 # save the return value + mov 0xff,d3 + + # Reinstall first breakpoint + mov (kgdb_sstep_bp_addr),a2 + cmp 0,a2 + beq 1f + movbu (a2),d0 + movbu d0,(kgdb_sstep_bp) + movbu d3,(a2) +#if defined(CONFIG_MN10300_CACHE_FLUSH_ICACHE) || defined(CONFIG_MN10300_CACHE_INV_ICACHE) + mov a2,d0 + mov a2,d1 + add 1,d1 + calls flush_icache_range +#endif +1: + + # Reinstall second breakpoint + mov (kgdb_sstep_bp_addr+4),a2 + cmp 0,a2 + beq 2f + movbu (a2),d0 + movbu d0,(kgdb_sstep_bp+1) + movbu d3,(a2) +#if defined(CONFIG_MN10300_CACHE_FLUSH_ICACHE) || defined(CONFIG_MN10300_CACHE_INV_ICACHE) + mov a2,d0 + mov a2,d1 + add 1,d1 + calls flush_icache_range +#endif +2: + + mov d3,(kgdb_single_step) + + # Restore the return value (the previous thread_struct pointer) + mov e4,a0 + mov a0,d0 + add 12,sp + bra __switch_back + +#endif /* CONFIG_KGDB */ |