[PATCH 1/2] m68k: Add infrastructure for machine-specific get_cycles()

[Geert Uytterhoeven <geert@linux-m68k.org>]

Currently get_cycles() always returns zero.  As get_cycles() is called to
add entropy to the random number generator pool, security can be increased
by adding a hook where platforms can provide their own implementation.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
 arch/m68k/include/asm/machdep.h |    1 +
 arch/m68k/include/asm/timex.h   |    5 +----
 arch/m68k/kernel/time.c         |   13 +++++++++++++
 3 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/arch/m68k/include/asm/machdep.h b/arch/m68k/include/asm/machdep.h
index 953ca21..334f751 100644
--- a/arch/m68k/include/asm/machdep.h
+++ b/arch/m68k/include/asm/machdep.h
@@ -22,6 +22,7 @@ extern unsigned int (*mach_get_ss)(void);
 extern int (*mach_get_rtc_pll)(struct rtc_pll_info *);
 extern int (*mach_set_rtc_pll)(struct rtc_pll_info *);
 extern int (*mach_set_clock_mmss)(unsigned long);
+extern cycles_t (*mach_get_cycles)(void);
 extern void (*mach_reset)( void );
 extern void (*mach_halt)( void );
 extern void (*mach_power_off)( void );
diff --git a/arch/m68k/include/asm/timex.h b/arch/m68k/include/asm/timex.h
index 6759dad..0fdc5d2 100644
--- a/arch/m68k/include/asm/timex.h
+++ b/arch/m68k/include/asm/timex.h
@@ -23,9 +23,6 @@
 
 typedef unsigned long cycles_t;
 
-static inline cycles_t get_cycles(void)
-{
-	return 0;
-}
+extern cycles_t get_cycles(void);
 
 #endif
diff --git a/arch/m68k/kernel/time.c b/arch/m68k/kernel/time.c
index 7eb9792..65b1663 100644
--- a/arch/m68k/kernel/time.c
+++ b/arch/m68k/kernel/time.c
@@ -28,6 +28,19 @@
 #include <linux/timex.h>
 #include <linux/profile.h>
 
+
+cycles_t (*mach_get_cycles)(void);
+
+cycles_t get_cycles(void)
+{
+	if (mach_get_cycles)
+		return mach_get_cycles();
+
+	return 0;
+}
+EXPORT_SYMBOL(get_cycles);
+
+
 /*
  * timer_interrupt() needs to keep up the real-time clock,
  * as well as call the "xtime_update()" routine every clocktick
-- 
1.7.9.5