[rtems commit] riscv: Implement CPU counter

[Sebastian Huber]

Module:    rtems
Branch:    master
Commit:    dd32e2b2d009de525c1a4ad488899fab355d8fed
Changeset: http://git.rtems.org/rtems/commit/?id=dd32e2b2d009de525c1a4ad488899fab355d8fed

Author:    Sebastian Huber <sebastian.huber at embedded-brains.de>
Date:      Fri Jul  6 08:12:40 2018 +0200

riscv: Implement CPU counter

Update #3433.

---

 bsps/riscv/riscv/clock/clockdrv.c                | 12 ++----------
 cpukit/score/cpu/riscv/Makefile.am               |  1 -
 cpukit/score/cpu/riscv/include/rtems/score/cpu.h | 17 ++++++++++++++++-
 3 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/bsps/riscv/riscv/clock/clockdrv.c b/bsps/riscv/riscv/clock/clockdrv.c
index 6a5d2db..d2d7a40 100644
--- a/bsps/riscv/riscv/clock/clockdrv.c
+++ b/bsps/riscv/riscv/clock/clockdrv.c
@@ -87,11 +87,6 @@ static uint32_t riscv_clock_get_timecount(struct timecounter *tc)
   return clint->mtime.val_32[0];
 }
 
-CPU_Counter_ticks _CPU_Counter_read(void)
-{
-  return riscv_clock_get_timecount(NULL);
-}
-
 static uint32_t riscv_clock_get_timebase_frequency(const void *fdt)
 {
   int node;
@@ -131,12 +126,9 @@ static void riscv_clock_initialize(void)
   rtems_timecounter_install(&riscv_clock_tc);
 }
 
-CPU_Counter_ticks _CPU_Counter_difference(
-  CPU_Counter_ticks second,
-  CPU_Counter_ticks first
-)
+uint32_t _CPU_Counter_frequency( void )
 {
-  return second - first;
+  return riscv_clock_get_timebase_frequency(bsp_fdt_get());
 }
 
 #define Clock_driver_support_at_tick() riscv_clock_at_tick()
diff --git a/cpukit/score/cpu/riscv/Makefile.am b/cpukit/score/cpu/riscv/Makefile.am
index e771468..3630c03 100644
--- a/cpukit/score/cpu/riscv/Makefile.am
+++ b/cpukit/score/cpu/riscv/Makefile.am
@@ -2,7 +2,6 @@ include $(top_srcdir)/automake/compile.am
 noinst_LIBRARIES = libscorecpu.a
 libscorecpu_a_CPPFLAGS = $(AM_CPPFLAGS)
 libscorecpu_a_SOURCES  = cpu.c
-libscorecpu_a_SOURCES += ../no_cpu/cpucounterfrequency.c
 libscorecpu_a_SOURCES += riscv-exception-handler.S
 libscorecpu_a_SOURCES += riscv-exception-default.c
 libscorecpu_a_SOURCES += riscv-exception-frame-print.c
diff --git a/cpukit/score/cpu/riscv/include/rtems/score/cpu.h b/cpukit/score/cpu/riscv/include/rtems/score/cpu.h
index e79ce25..f84395c 100644
--- a/cpukit/score/cpu/riscv/include/rtems/score/cpu.h
+++ b/cpukit/score/cpu/riscv/include/rtems/score/cpu.h
@@ -370,7 +370,22 @@ typedef uint32_t CPU_Counter_ticks;
 
 uint32_t _CPU_Counter_frequency( void );
 
-CPU_Counter_ticks _CPU_Counter_read( void );
+static inline CPU_Counter_ticks _CPU_Counter_read( void )
+{
+  unsigned long ticks;
+
+  __asm__ volatile ( "rdtime %0" : "=&r" ( ticks ) );
+
+  return (uint32_t) ticks;
+}
+
+static inline CPU_Counter_ticks _CPU_Counter_difference(
+  CPU_Counter_ticks second,
+  CPU_Counter_ticks first
+)
+{
+  return second - first;
+}
 
 #ifdef RTEMS_SMP