[S390] ftrace: add dynamic ftrace support

Dynamic ftrace support for s390.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 25 insertions, 2 deletions

diff --git a/arch/s390/include/asm/ftrace.h b/arch/s390/include/asm/ftrace.h
index 5a5bc75e19d4..ba23d8f97d07 100644
--- a/arch/s390/include/asm/ftrace.h
+++ b/arch/s390/include/asm/ftrace.h
@@ -2,7 +2,26 @@
 #define _ASM_S390_FTRACE_H
 
 #ifndef __ASSEMBLY__
+
 extern void _mcount(void);
+extern unsigned long ftrace_dyn_func;
+
+struct dyn_arch_ftrace { };
+
+#define MCOUNT_ADDR ((long)_mcount)
+
+#ifdef CONFIG_64BIT
+#define MCOUNT_INSN_SIZE 24
+#define MCOUNT_OFFSET    14
+#else
+#define MCOUNT_INSN_SIZE 30
+#define MCOUNT_OFFSET     8
 #endif
 
+static inline unsigned long ftrace_call_adjust(unsigned long addr)
+{
+        return addr - MCOUNT_OFFSET;
+}
+
+#endif /* __ASSEMBLY__ */
 #endif /* _ASM_S390_FTRACE_H */
diff --git a/arch/s390/include/asm/lowcore.h b/arch/s390/include/asm/lowcore.h
index 713fe9fb1fcc..5046ad6b7a63 100644
--- a/arch/s390/include/asm/lowcore.h
+++ b/arch/s390/include/asm/lowcore.h
@@ -68,6 +68,7 @@
 #define __LC_CPUID                      0x02b0
 #define __LC_INT_CLOCK                  0x02c8
 #define __LC_MACHINE_FLAGS              0x02d8
+#define __LC_FTRACE_FUNC                0x02dc
 #define __LC_IRB                        0x0300
 #define __LC_PFAULT_INTPARM             0x0080
 #define __LC_CPU_TIMER_SAVE_AREA        0x00d8
@@ -113,6 +114,7 @@
 #define __LC_INT_CLOCK                  0x0340
 #define __LC_VDSO_PER_CPU               0x0350
 #define __LC_MACHINE_FLAGS              0x0358
+#define __LC_FTRACE_FUNC                0x0360
 #define __LC_IRB                        0x0380
 #define __LC_PASTE                      0x03c0
 #define __LC_PFAULT_INTPARM             0x11b8
@@ -281,7 +283,8 @@ struct _lowcore
         __u64   int_clock;                      /* 0x02c8 */
         __u64   clock_comparator;               /* 0x02d0 */
         __u32   machine_flags;                  /* 0x02d8 */
-        __u8    pad_0x02dc[0x0300-0x02dc];      /* 0x02dc */
+        __u32   ftrace_func;                    /* 0x02dc */
+        __u8    pad_0x02f0[0x0300-0x02f0];      /* 0x02f0 */
 
         /* Interrupt response block */
         __u8    irb[64];                        /* 0x0300 */
@@ -386,7 +389,8 @@ struct _lowcore
         __u64   clock_comparator;               /* 0x0348 */
         __u64   vdso_per_cpu_data;              /* 0x0350 */
         __u64   machine_flags;                  /* 0x0358 */
-        __u8    pad_0x0360[0x0380-0x0360];      /* 0x0360 */
+        __u64   ftrace_func;                    /* 0x0360 */
+        __u8    pad_0x0368[0x0380-0x0368];      /* 0x0368 */
 
         /* Interrupt response block. */
         __u8    irb[64];                        /* 0x0380 */