sparc64: Add proper dynamic ftrace support.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 45 insertions, 15 deletions

diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 2185cf946d68..3f8b6a92eabd 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -37,6 +37,8 @@ config SPARC64
         select HAVE_KPROBES
         select HAVE_LMB
         select HAVE_SYSCALL_WRAPPERS
+        select HAVE_DYNAMIC_FTRACE
+        select HAVE_FTRACE_MCOUNT_RECORD
         select USE_GENERIC_SMP_HELPERS if SMP
         select RTC_DRV_CMOS
         select RTC_DRV_BQ4802
diff --git a/arch/sparc/include/asm/ftrace.h b/arch/sparc/include/asm/ftrace.h
index d27716cd38c1..b0f18e9893db 100644
--- a/arch/sparc/include/asm/ftrace.h
+++ b/arch/sparc/include/asm/ftrace.h
@@ -11,4 +11,15 @@ extern void _mcount(void);
 
 #endif
 
+#ifdef CONFIG_DYNAMIC_FTRACE
+/* reloction of mcount call site is the same as the address */
+static inline unsigned long ftrace_call_adjust(unsigned long addr)
+{
+        return addr;
+}
+
+struct dyn_arch_ftrace {
+};
+#endif /*  CONFIG_DYNAMIC_FTRACE */
+
 #endif /* _ASM_SPARC64_FTRACE */
diff --git a/arch/sparc/kernel/ftrace.c b/arch/sparc/kernel/ftrace.c
index d0218e73f982..d3b1a3076569 100644
--- a/arch/sparc/kernel/ftrace.c
+++ b/arch/sparc/kernel/ftrace.c
@@ -7,14 +7,10 @@
 
 #include <asm/ftrace.h>
 
+#ifdef CONFIG_DYNAMIC_FTRACE
 static const u32 ftrace_nop = 0x01000000;
 
-unsigned char *ftrace_nop_replace(void)
-{
-        return (char *)&ftrace_nop;
-}
-
-unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
+static u32 ftrace_call_replace(unsigned long ip, unsigned long addr)
 {
         static u32 call;
         s32 off;
@@ -22,15 +18,11 @@ unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
         off = ((s32)addr - (s32)ip);
         call = 0x40000000 | ((u32)off >> 2);
 
-        return (unsigned char *) &call;
+        return call;
 }
 
-int
-ftrace_modify_code(unsigned long ip, unsigned char *old_code,
-                   unsigned char *new_code)
+static int ftrace_modify_code(unsigned long ip, u32 old, u32 new)
 {
-        u32 old = *(u32 *)old_code;
-        u32 new = *(u32 *)new_code;
         u32 replaced;
         int faulted;
 
@@ -59,18 +51,43 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code,
         return faulted;
 }
 
+int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr)
+{
+        unsigned long ip = rec->ip;
+        u32 old, new;
+
+        old = ftrace_call_replace(ip, addr);
+        new = ftrace_nop;
+        return ftrace_modify_code(ip, old, new);
+}
+
+int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
+{
+        unsigned long ip = rec->ip;
+        u32 old, new;
+
+        old = ftrace_nop;
+        new = ftrace_call_replace(ip, addr);
+        return ftrace_modify_code(ip, old, new);
+}
+
 int ftrace_update_ftrace_func(ftrace_func_t func)
 {
         unsigned long ip = (unsigned long)(&ftrace_call);
-        unsigned char old[MCOUNT_INSN_SIZE], *new;
+        u32 old, new;
 
-        memcpy(old, &ftrace_call, MCOUNT_INSN_SIZE);
+        old = *(u32 *) &ftrace_call;
         new = ftrace_call_replace(ip, (unsigned long)func);
         return ftrace_modify_code(ip, old, new);
 }
 
 int __init ftrace_dyn_arch_init(void *data)
 {
-        ftrace_mcount_set(data);
+        unsigned long *p = data;
+
+        *p = 0;
+
         return 0;
 }
+#endif
+