Add _CPU_Counter_frequency()

Add rtems_counter_frequency() API function.  Use it to initialize the
counter value converter via the new system initialization step
(RTEMS_SYSINIT_CPU_COUNTER).  This decouples the counter implementation
and the counter converter.  It avoids an unnecessary pull in of the
64-bit integer division from libgcc.

Update #3456.

11 files changed, 43 insertions, 34 deletions

diff --git a/bsps/arm/altera-cyclone-v/start/bspstart.c b/bsps/arm/altera-cyclone-v/start/bspstart.c
index 0345a4c0a7..c7eae97fdc 100644
--- a/bsps/arm/altera-cyclone-v/start/bspstart.c
+++ b/bsps/arm/altera-cyclone-v/start/bspstart.c
@@ -13,7 +13,6 @@
  */
 
 #include <bsp/bootcard.h>
-#include <bsp/arm-a9mpcore-clock.h>
 #include <bsp/fdt.h>
 #include <bsp/irq-generic.h>
 #include <bsp/linker-symbols.h>
@@ -95,7 +94,6 @@ static void update_clocks(void)
 void bsp_start(void)
 {
   update_clocks();
-  a9mpcore_clock_initialize_early();
   bsp_interrupt_initialize();
   rtems_cache_coherent_add_area(
     bsp_section_nocacheheap_begin,
diff --git a/bsps/arm/include/bsp/arm-a9mpcore-clock.h b/bsps/arm/include/bsp/arm-a9mpcore-clock.h
index 9a8c653801..8d6007ba03 100644
--- a/bsps/arm/include/bsp/arm-a9mpcore-clock.h
+++ b/bsps/arm/include/bsp/arm-a9mpcore-clock.h
@@ -22,15 +22,6 @@ extern "C" {
  */
 uint32_t a9mpcore_clock_periphclk(void);
 
-/**
- * @brief Do early clock initialization so that the CPU counter conversion
- * works.
- */
-static inline void a9mpcore_clock_initialize_early(void)
-{
-  rtems_counter_initialize_converter(a9mpcore_clock_periphclk());
-}
-
 #ifdef __cplusplus
 }
 #endif /* __cplusplus */
diff --git a/bsps/arm/lpc176x/start/system-clocks.c b/bsps/arm/lpc176x/start/system-clocks.c
index dd1a0308c6..2ec58727eb 100644
--- a/bsps/arm/lpc176x/start/system-clocks.c
+++ b/bsps/arm/lpc176x/start/system-clocks.c
@@ -109,6 +109,11 @@ unsigned lpc176x_cclk( void )
   return cclk;
 }
 
+uint32_t _CPU_Counter_frequency(void)
+{
+  return LPC176X_PCLK;
+}
+
 CPU_Counter_ticks _CPU_Counter_read( void )
 {
   return lpc176x_get_timer1();
diff --git a/bsps/arm/lpc24xx/start/system-clocks.c b/bsps/arm/lpc24xx/start/system-clocks.c
index f64fca1bed..8a2f62b4b0 100644
--- a/bsps/arm/lpc24xx/start/system-clocks.c
+++ b/bsps/arm/lpc24xx/start/system-clocks.c
@@ -61,8 +61,11 @@ void lpc24xx_timer_initialize(void)
 
   /* Start timer */
   T1TCR = TCR_EN;
+}
 
-  rtems_counter_initialize_converter(LPC24XX_PCLK);
+uint32_t _CPU_Counter_frequency(void)
+{
+  return LPC24XX_PCLK;
 }
 
 CPU_Counter_ticks _CPU_Counter_read(void)
diff --git a/bsps/arm/lpc32xx/start/bspstart.c b/bsps/arm/lpc32xx/start/bspstart.c
index 7ade16bbb8..c535f766d7 100644
--- a/bsps/arm/lpc32xx/start/bspstart.c
+++ b/bsps/arm/lpc32xx/start/bspstart.c
@@ -26,6 +26,11 @@
 #include <bsp/bootcard.h>
 #include <bsp/irq-generic.h>
 
+uint32_t _CPU_Counter_frequency(void)
+{
+  return LPC32XX_PERIPH_CLK;
+}
+
 CPU_Counter_ticks _CPU_Counter_read(void)
 {
   return lpc32xx_timer();
@@ -33,6 +38,5 @@ CPU_Counter_ticks _CPU_Counter_read(void)
 
 void bsp_start(void)
 {
-  rtems_counter_initialize_converter(LPC32XX_PERIPH_CLK);
   bsp_interrupt_initialize();
 }
diff --git a/bsps/arm/realview-pbx-a9/start/bspstart.c b/bsps/arm/realview-pbx-a9/start/bspstart.c
index 0be515c057..8660c661c9 100644
--- a/bsps/arm/realview-pbx-a9/start/bspstart.c
+++ b/bsps/arm/realview-pbx-a9/start/bspstart.c
@@ -14,11 +14,9 @@
 
 #include <bsp.h>
 #include <bsp/bootcard.h>
-#include <bsp/arm-a9mpcore-clock.h>
 #include <bsp/irq-generic.h>
 
 void bsp_start(void)
 {
-  a9mpcore_clock_initialize_early();
   bsp_interrupt_initialize();
 }
diff --git a/bsps/arm/shared/clock/clock-a9mpcore.c b/bsps/arm/shared/clock/clock-a9mpcore.c
index f9b2d08c9b..a68a627c5b 100644
--- a/bsps/arm/shared/clock/clock-a9mpcore.c
+++ b/bsps/arm/shared/clock/clock-a9mpcore.c
@@ -157,6 +157,11 @@ static void a9mpcore_clock_initialize(void)
   rtems_timecounter_install(&a9mpcore_tc);
 }
 
+uint32_t _CPU_Counter_frequency(void)
+{
+  return a9mpcore_clock_periphclk();
+}
+
 CPU_Counter_ticks _CPU_Counter_read(void)
 {
   volatile a9mpcore_gt *gt = A9MPCORE_GT;
diff --git a/bsps/arm/shared/clock/clock-generic-timer.c b/bsps/arm/shared/clock/clock-generic-timer.c
index 8a992d44f4..2cb85003e1 100644
--- a/bsps/arm/shared/clock/clock-generic-timer.c
+++ b/bsps/arm/shared/clock/clock-generic-timer.c
@@ -166,6 +166,11 @@ static void arm_gt_clock_initialize(void)
   rtems_timecounter_install(tc);
 }
 
+uint32_t _CPU_Counter_frequency(void)
+{
+  return arm_gt_clock_instance.interval;
+}
+
 CPU_Counter_ticks _CPU_Counter_read(void)
 {
   return (uint32_t) arm_gt_clock_get_count();
@@ -179,14 +184,12 @@ static void arm_gt_clock_early_init(void)
     &arm_gt_clock_instance.interval,
     &arm_gt_clock_instance.irq
   );
-
-  rtems_counter_initialize_converter(arm_gt_clock_instance.interval);
 }
 
 RTEMS_SYSINIT_ITEM(
   arm_gt_clock_early_init,
-  RTEMS_SYSINIT_BSP_START,
-  RTEMS_SYSINIT_ORDER_LAST
+  RTEMS_SYSINIT_CPU_COUNTER,
+  RTEMS_SYSINIT_ORDER_FIRST
 );
 
 #define Clock_driver_support_at_tick() \
diff --git a/bsps/arm/shared/cpucounter/cpucounter-armv7m.c b/bsps/arm/shared/cpucounter/cpucounter-armv7m.c
index 7d2581879f..b7593602ed 100644
--- a/bsps/arm/shared/cpucounter/cpucounter-armv7m.c
+++ b/bsps/arm/shared/cpucounter/cpucounter-armv7m.c
@@ -19,6 +19,16 @@
 #include <bsp.h>
 #include <bsp/fatal.h>
 
+uint32_t _CPU_Counter_frequency(void)
+{
+#ifdef BSP_ARMV7M_SYSTICK_FREQUENCY
+  return = BSP_ARMV7M_SYSTICK_FREQUENCY;
+#else
+  volatile ARMV7M_Systick *systick = _ARMV7M_Systick;
+  return ARMV7M_SYSTICK_CALIB_TENMS_GET(systick->calib) * 100;
+#endif
+}
+
 CPU_Counter_ticks _CPU_Counter_read(void)
 {
   volatile ARMV7M_DWT *dwt = _ARMV7M_DWT;
@@ -32,22 +42,13 @@ static void armv7m_cpu_counter_initialize(void)
 
   cyccnt_enabled = _ARMV7M_DWT_Enable_CYCCNT();
 
-  if (cyccnt_enabled) {
-    #ifdef BSP_ARMV7M_SYSTICK_FREQUENCY
-      uint64_t freq = BSP_ARMV7M_SYSTICK_FREQUENCY;
-    #else
-      volatile ARMV7M_Systick *systick = _ARMV7M_Systick;
-      uint64_t freq = ARMV7M_SYSTICK_CALIB_TENMS_GET(systick->calib) * 100ULL;
-    #endif
-
-    rtems_counter_initialize_converter(freq);
-  } else {
+  if (!cyccnt_enabled) {
     bsp_fatal(BSP_ARM_ARMV7M_CPU_COUNTER_INIT);
   }
 }
 
 RTEMS_SYSINIT_ITEM(
   armv7m_cpu_counter_initialize,
-  RTEMS_SYSINIT_BSP_START,
+  RTEMS_SYSINIT_CPU_COUNTER,
   RTEMS_SYSINIT_ORDER_FIRST
 );
diff --git a/bsps/arm/tms570/cpucounter/cpucounterread.c b/bsps/arm/tms570/cpucounter/cpucounterread.c
index c5e62d382d..ada65a87ed 100644
--- a/bsps/arm/tms570/cpucounter/cpucounterread.c
+++ b/bsps/arm/tms570/cpucounter/cpucounterread.c
@@ -46,8 +46,11 @@ static void tms570_cpu_counter_initialize(void)
   pmcr &= ~ARM_CP15_PMCR_D;
   pmcr |= ARM_CP15_PMCR_E;
   arm_cp15_set_performance_monitors_control(pmcr);
+}
 
-  rtems_counter_initialize_converter(2 * BSP_PLL_OUT_CLOCK);
+uint32_t _CPU_Counter_frequency(void)
+{
+  return 2 * BSP_PLL_OUT_CLOCK;
 }
 
 CPU_Counter_ticks _CPU_Counter_read(void)
@@ -57,6 +60,6 @@ CPU_Counter_ticks _CPU_Counter_read(void)
 
 RTEMS_SYSINIT_ITEM(
   tms570_cpu_counter_initialize,
-  RTEMS_SYSINIT_BSP_START,
+  RTEMS_SYSINIT_CPU_COUNTER,
   RTEMS_SYSINIT_ORDER_FIRST
 );
diff --git a/bsps/arm/xilinx-zynq/start/bspstart.c b/bsps/arm/xilinx-zynq/start/bspstart.c
index 14a20df7ef..4e975e872b 100644
--- a/bsps/arm/xilinx-zynq/start/bspstart.c
+++ b/bsps/arm/xilinx-zynq/start/bspstart.c
@@ -14,7 +14,6 @@
 
 #include <bsp.h>
 #include <bsp/bootcard.h>
-#include <bsp/arm-a9mpcore-clock.h>
 #include <bsp/irq-generic.h>
 #include <bsp/linker-symbols.h>
 
@@ -25,7 +24,6 @@ __attribute__ ((weak)) uint32_t zynq_clock_cpu_1x(void)
 
 void bsp_start(void)
 {
-  a9mpcore_clock_initialize_early();
   bsp_interrupt_initialize();
   rtems_cache_coherent_add_area(
     bsp_section_nocacheheap_begin,