microblaze: Fix ftrace

- Do not trace idle loop which takes a lot time
- Fix cache handling in generic ftrace code
- Do not trace lib functions ashldi3, ashrdi3, lshrdi3
  Functions are called from generic ftrace code which
  can't be traced

Signed-off-by: Michal Simek <monstr@monstr.eu>

2 files changed, 7 insertions, 4 deletions

diff --git a/arch/microblaze/kernel/Makefile b/arch/microblaze/kernel/Makefile
index f0cb5c26c81c..494b63b72dd7 100644
--- a/arch/microblaze/kernel/Makefile
+++ b/arch/microblaze/kernel/Makefile
@@ -10,6 +10,7 @@ CFLAGS_REMOVE_early_printk.o = -pg
 CFLAGS_REMOVE_selfmod.o = -pg
 CFLAGS_REMOVE_heartbeat.o = -pg
 CFLAGS_REMOVE_ftrace.o = -pg
+CFLAGS_REMOVE_process.o = -pg
 endif
 
 extra-y := head.o vmlinux.lds
diff --git a/arch/microblaze/kernel/ftrace.c b/arch/microblaze/kernel/ftrace.c
index 515feb404555..357d56abe24a 100644
--- a/arch/microblaze/kernel/ftrace.c
+++ b/arch/microblaze/kernel/ftrace.c
@@ -51,6 +51,9 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
                         : "r" (parent), "r" (return_hooker)
         );
 
+        flush_dcache_range((u32)parent, (u32)parent + 4);
+        flush_icache_range((u32)parent, (u32)parent + 4);
+
         if (unlikely(faulted)) {
                 ftrace_graph_stop();
                 WARN_ON(1);
@@ -95,6 +98,9 @@ static int ftrace_modify_code(unsigned long addr, unsigned int value)
         if (unlikely(faulted))
                 return -EFAULT;
 
+        flush_dcache_range(addr, addr + 4);
+        flush_icache_range(addr, addr + 4);
+
         return 0;
 }
 
@@ -195,8 +201,6 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
         ret += ftrace_modify_code((unsigned long)&ftrace_caller,
                                   MICROBLAZE_NOP);
 
-        /* All changes are done - lets do caches consistent */
-        flush_icache();
         return ret;
 }
 
@@ -210,7 +214,6 @@ int ftrace_enable_ftrace_graph_caller(void)
 
         old_jump = *(unsigned int *)ip; /* save jump over instruction */
         ret = ftrace_modify_code(ip, MICROBLAZE_NOP);
-        flush_icache();
 
         pr_debug("%s: Replace instruction: 0x%x\n", __func__, old_jump);
         return ret;
@@ -222,7 +225,6 @@ int ftrace_disable_ftrace_graph_caller(void)
         unsigned long ip = (unsigned long)(&ftrace_call_graph);
 
         ret = ftrace_modify_code(ip, old_jump);
-        flush_icache();
 
         pr_debug("%s\n", __func__);
         return ret;