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-rw-r--r--arch/mn10300/kernel/switch_to.S111
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 */