Blackfin arch: disable pthread stack check for SMP at runtime

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

4 files changed, 22 insertions, 0 deletions

diff --git a/arch/blackfin/include/asm/l1layout.h b/arch/blackfin/include/asm/l1layout.h
index 06bb37f6c788..79dbefaa5bef 100644
--- a/arch/blackfin/include/asm/l1layout.h
+++ b/arch/blackfin/include/asm/l1layout.h
@@ -8,6 +8,7 @@
 
 #include <asm/blackfin.h>
 
+#ifndef CONFIG_SMP
 #ifndef __ASSEMBLY__
 
 /* Data that is "mapped" into the process VM at the start of the L1 scratch
@@ -28,5 +29,6 @@ struct l1_scratch_task_info
                                                 get_l1_scratch_start())
 
 #endif
+#endif
 
 #endif
diff --git a/arch/blackfin/include/asm/processor.h b/arch/blackfin/include/asm/processor.h
index 83d57a85b14f..0eece23b41c7 100644
--- a/arch/blackfin/include/asm/processor.h
+++ b/arch/blackfin/include/asm/processor.h
@@ -65,6 +65,7 @@ struct thread_struct {
  * pass the data segment into user programs if it exists,
  * it can't hurt anything as far as I can tell
  */
+#ifndef CONFIG_SMP
 #define start_thread(_regs, _pc, _usp)                                  \
 do {                                                                    \
         set_fs(USER_DS);                                                \
@@ -78,6 +79,16 @@ do {									\
                 sizeof(*L1_SCRATCH_TASK_INFO));                         \
         wrusp(_usp);                                                    \
 } while(0)
+#else
+#define start_thread(_regs, _pc, _usp)                                  \
+do {                                                                    \
+        set_fs(USER_DS);                                                \
+        (_regs)->pc = (_pc);                                            \
+        if (current->mm)                                                \
+                (_regs)->p5 = current->mm->start_data;                  \
+        wrusp(_usp);                                                    \
+} while (0)
+#endif
 
 /* Forward declaration, a strange C thing */
 struct task_struct;
diff --git a/arch/blackfin/include/asm/system.h b/arch/blackfin/include/asm/system.h
index aa7d87b62b28..812e6e6e2cee 100644
--- a/arch/blackfin/include/asm/system.h
+++ b/arch/blackfin/include/asm/system.h
@@ -197,6 +197,7 @@ static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
 
 asmlinkage struct task_struct *resume(struct task_struct *prev, struct task_struct *next);
 
+#ifndef CONFIG_SMP
 #define switch_to(prev,next,last) \
 do {    \
         memcpy (&task_thread_info(prev)->l1_task_info, L1_SCRATCH_TASK_INFO, \
@@ -205,5 +206,11 @@ do {    \
                 sizeof *L1_SCRATCH_TASK_INFO); \
         (last) = resume (prev, next);   \
 } while (0)
+#else
+#define switch_to(prev, next, last) \
+do {    \
+        (last) = resume(prev, next);   \
+} while (0)
+#endif
 
 #endif  /* _BLACKFIN_SYSTEM_H */
diff --git a/arch/blackfin/include/asm/thread_info.h b/arch/blackfin/include/asm/thread_info.h
index 7eaf2e2606d9..e721ce55956c 100644
--- a/arch/blackfin/include/asm/thread_info.h
+++ b/arch/blackfin/include/asm/thread_info.h
@@ -63,7 +63,9 @@ struct thread_info {
         int preempt_count;      /* 0 => preemptable, <0 => BUG */
         mm_segment_t addr_limit;        /* address limit */
         struct restart_block restart_block;
+#ifndef CONFIG_SMP
         struct l1_scratch_task_info l1_task_info;
+#endif
 };
 
 /*