[PATCH] sparc: Fix CPU counter support
Sebastian Huber
sebastian.huber at embedded-brains.de
Mon Feb 24 12:01:10 UTC 2014
The SPARC processors supported by RTEMS have no built-in CPU counter
support. We have to use some hardware counter module for this purpose.
The BSP must provide a 32-bit register which contains the current CPU
counter value and a function for the difference calculation. It can use
for example the GPTIMER instance used for the clock driver.
---
c/src/lib/libbsp/sparc/erc32/Makefile.am | 1 -
c/src/lib/libbsp/sparc/erc32/clock/ckinit.c | 14 +++
c/src/lib/libbsp/sparc/leon2/Makefile.am | 1 -
c/src/lib/libbsp/sparc/leon3/clock/ckinit.c | 7 --
c/src/lib/libbsp/sparc/leon3/include/leon.h | 7 ++
c/src/lib/libbsp/sparc/leon3/startup/cpucounter.c | 95 ++++++++++++++------
cpukit/score/cpu/sparc/Makefile.am | 1 +
cpukit/score/cpu/sparc/rtems/score/cpu.h | 51 +++++++++++-
cpukit/score/cpu/sparc/sparc-counter.c | 34 ++++++++
9 files changed, 171 insertions(+), 40 deletions(-)
create mode 100644 cpukit/score/cpu/sparc/sparc-counter.c
diff --git a/c/src/lib/libbsp/sparc/erc32/Makefile.am b/c/src/lib/libbsp/sparc/erc32/Makefile.am
index 61cd9dc..16aecca 100644
--- a/c/src/lib/libbsp/sparc/erc32/Makefile.am
+++ b/c/src/lib/libbsp/sparc/erc32/Makefile.am
@@ -35,7 +35,6 @@ libbsp_a_SOURCES += ../../shared/bspclean.c ../../shared/bsplibc.c \
../../shared/sbrk.c startup/setvec.c startup/spurious.c \
startup/erc32mec.c startup/boardinit.S startup/bspidle.c \
startup/bspdelay.c ../../sparc/shared/startup/early_malloc.c
-libbsp_a_SOURCES += ../../shared/cpucounterread.c
# ISR Handler
libbsp_a_SOURCES += ../../sparc/shared/irq_asm.S
# gnatsupp
diff --git a/c/src/lib/libbsp/sparc/erc32/clock/ckinit.c b/c/src/lib/libbsp/sparc/erc32/clock/ckinit.c
index 1287645..1d85c32 100644
--- a/c/src/lib/libbsp/sparc/erc32/clock/ckinit.c
+++ b/c/src/lib/libbsp/sparc/erc32/clock/ckinit.c
@@ -24,6 +24,7 @@
#include <bsp.h>
#include <bspopts.h>
+#include <rtems/counter.h>
#if SIMSPARC_FAST_IDLE==1
#define CLOCK_DRIVER_USE_FAST_IDLE 1
@@ -63,6 +64,14 @@ uint32_t bsp_clock_nanoseconds_since_last_tick(void)
#define Clock_driver_nanoseconds_since_last_tick \
bsp_clock_nanoseconds_since_last_tick
+static CPU_Counter_ticks erc32_counter_difference(
+ CPU_Counter_ticks second,
+ CPU_Counter_ticks first
+)
+{
+ return (first - second) % rtems_configuration_get_microseconds_per_tick();
+}
+
#define Clock_driver_support_initialize_hardware() \
do { \
/* approximately 1 us per countdown */ \
@@ -80,6 +89,11 @@ uint32_t bsp_clock_nanoseconds_since_last_tick(void)
ERC32_MEC_TIMER_COUNTER_ENABLE_COUNTING | \
ERC32_MEC_TIMER_COUNTER_RELOAD_AT_ZERO \
); \
+ _SPARC_Counter_initialize( \
+ &ERC32_MEC.Real_Time_Clock_Counter, \
+ erc32_counter_difference \
+ ); \
+ rtems_counter_initialize_converter(1000000); \
} while (0)
#define Clock_driver_support_shutdown_hardware() \
diff --git a/c/src/lib/libbsp/sparc/leon2/Makefile.am b/c/src/lib/libbsp/sparc/leon2/Makefile.am
index 8bbe69b..c08f159 100644
--- a/c/src/lib/libbsp/sparc/leon2/Makefile.am
+++ b/c/src/lib/libbsp/sparc/leon2/Makefile.am
@@ -52,7 +52,6 @@ libbsp_a_SOURCES += ../../shared/bspclean.c ../../shared/bsplibc.c \
../../shared/sbrk.c startup/setvec.c startup/spurious.c startup/bspidle.c \
../../shared/bspinit.c startup/bspdelay.c \
../../sparc/shared/startup/early_malloc.c
-libbsp_a_SOURCES += ../../shared/cpucounterread.c
# ISR Handler
libbsp_a_SOURCES += ../../sparc/shared/irq_asm.S
# gnatsupp
diff --git a/c/src/lib/libbsp/sparc/leon3/clock/ckinit.c b/c/src/lib/libbsp/sparc/leon3/clock/ckinit.c
index e0556ba..d2aae23 100644
--- a/c/src/lib/libbsp/sparc/leon3/clock/ckinit.c
+++ b/c/src/lib/libbsp/sparc/leon3/clock/ckinit.c
@@ -30,13 +30,6 @@
* The Real Time Clock Counter Timer uses this trap type.
*/
-#if defined(RTEMS_MULTIPROCESSING)
- #define LEON3_CLOCK_INDEX \
- (rtems_configuration_get_user_multiprocessing_table() ? LEON3_Cpu_Index : 0)
-#else
- #define LEON3_CLOCK_INDEX 0
-#endif
-
volatile struct gptimer_regs *LEON3_Timer_Regs = 0;
static int clkirq;
diff --git a/c/src/lib/libbsp/sparc/leon3/include/leon.h b/c/src/lib/libbsp/sparc/leon3/include/leon.h
index ccee1a3..e4710cd 100644
--- a/c/src/lib/libbsp/sparc/leon3/include/leon.h
+++ b/c/src/lib/libbsp/sparc/leon3/include/leon.h
@@ -273,6 +273,13 @@ extern rtems_interrupt_lock LEON3_IrqCtrl_Lock;
#define LEON_REG_TIMER_COUNTER_DEFINED_MASK 0x00000003
#define LEON_REG_TIMER_COUNTER_CURRENT_MODE_MASK 0x00000003
+#if defined(RTEMS_MULTIPROCESSING)
+ #define LEON3_CLOCK_INDEX \
+ (rtems_configuration_get_user_multiprocessing_table() ? LEON3_Cpu_Index : 0)
+#else
+ #define LEON3_CLOCK_INDEX 0
+#endif
+
/* Load 32-bit word by forcing a cache-miss */
static inline unsigned int leon_r32_no_cache(uintptr_t addr)
{
diff --git a/c/src/lib/libbsp/sparc/leon3/startup/cpucounter.c b/c/src/lib/libbsp/sparc/leon3/startup/cpucounter.c
index e773d4d..5d1ac0c 100644
--- a/c/src/lib/libbsp/sparc/leon3/startup/cpucounter.c
+++ b/c/src/lib/libbsp/sparc/leon3/startup/cpucounter.c
@@ -12,22 +12,53 @@
* http://www.rtems.com/license/LICENSE.
*/
-#include <bsp.h>
-#include <bsp/fatal.h>
#include <leon.h>
#include <rtems/counter.h>
-static volatile struct gptimer_regs *leon3_cpu_counter_gpt;
+static volatile struct gptimer_regs *adev_to_gpt(struct ambapp_dev *adev)
+{
+ return (volatile struct gptimer_regs *) DEV_TO_APB(adev)->start;
+}
+
+static CPU_Counter_ticks free_counter_difference(
+ CPU_Counter_ticks second,
+ CPU_Counter_ticks first
+)
+{
+ return first - second;
+}
+
+static CPU_Counter_ticks clock_counter_difference(
+ CPU_Counter_ticks second,
+ CPU_Counter_ticks first
+)
+{
+ return (first - second) % rtems_configuration_get_microseconds_per_tick();
+}
+
+static void gpt_counter_initialize(
+ volatile struct gptimer_regs *gpt,
+ size_t timer_index,
+ uint32_t frequency,
+ SPARC_Counter_difference counter_difference
+)
+{
+ _SPARC_Counter_initialize(
+ (volatile const uint32_t *) &gpt->timer[timer_index].value,
+ counter_difference
+ );
+
+ rtems_counter_initialize_converter(frequency);
+}
void leon3_cpu_counter_initialize(void)
{
struct ambapp_dev *adev;
int idx = 1;
- volatile struct gptimer_regs *gpt;
- unsigned new_prescaler = 8;
- unsigned prescaler;
- uint32_t frequency;
+
+ /* Assume that GRMON initialized the timer to 1MHz */
+ uint32_t frequency = 1000000;
adev = (void *) ambapp_for_each(
&ambapp_plb,
@@ -37,28 +68,34 @@ void leon3_cpu_counter_initialize(void)
ambapp_find_by_idx,
&idx
);
- if (adev == NULL) {
- bsp_fatal(LEON3_FATAL_CPU_COUNTER_INIT);
- }
+ if (adev != NULL) {
+ volatile struct gptimer_regs *gpt = adev_to_gpt(adev);
+ unsigned new_prescaler = 8;
+ unsigned prescaler = gpt->scaler_reload + 1;
- gpt = (volatile struct gptimer_regs *) DEV_TO_APB(adev)->start;
+ gpt->scaler_reload = new_prescaler - 1;
+ gpt->timer[0].reload = 0xffffffff;
+ gpt->timer[0].ctrl = LEON3_GPTIMER_EN | LEON3_GPTIMER_RL
+ | LEON3_GPTIMER_LD;
- prescaler = gpt->scaler_reload + 1;
- gpt->scaler_reload = new_prescaler - 1;
- gpt->timer[0].reload = 0xffffffff;
- gpt->timer[0].ctrl = LEON3_GPTIMER_EN | LEON3_GPTIMER_RL
- | LEON3_GPTIMER_LD;
-
- leon3_cpu_counter_gpt = gpt;
-
- /* Assume that GRMON initialized the timer to 1MHz */
- frequency = UINT32_C(1000000) * (prescaler / new_prescaler);
- rtems_counter_initialize_converter(frequency);
-}
-
-CPU_Counter_ticks _CPU_Counter_read(void)
-{
- volatile struct gptimer_regs *gpt = leon3_cpu_counter_gpt;
-
- return 0U - gpt->timer[0].value;
+ frequency = (frequency * prescaler) / new_prescaler;
+ gpt_counter_initialize(gpt, 0, frequency, free_counter_difference);
+ } else {
+ adev = (void *) ambapp_for_each(
+ &ambapp_plb,
+ OPTIONS_ALL | OPTIONS_APB_SLVS,
+ VENDOR_GAISLER,
+ GAISLER_GPTIMER,
+ ambapp_find_by_idx,
+ NULL
+ );
+ if (adev != NULL) {
+ gpt_counter_initialize(
+ adev_to_gpt(adev),
+ LEON3_CLOCK_INDEX,
+ frequency,
+ clock_counter_difference
+ );
+ }
+ }
}
diff --git a/cpukit/score/cpu/sparc/Makefile.am b/cpukit/score/cpu/sparc/Makefile.am
index 504a575..c6ea1c3 100644
--- a/cpukit/score/cpu/sparc/Makefile.am
+++ b/cpukit/score/cpu/sparc/Makefile.am
@@ -11,6 +11,7 @@ include_rtems_score_HEADERS += rtems/score/cpuatomic.h
noinst_LIBRARIES = libscorecpu.a
libscorecpu_a_SOURCES = cpu.c cpu_asm.S
+libscorecpu_a_SOURCES += sparc-counter.c
libscorecpu_a_SOURCES += sparcv8-atomic.c
libscorecpu_a_CPPFLAGS = $(AM_CPPFLAGS)
diff --git a/cpukit/score/cpu/sparc/rtems/score/cpu.h b/cpukit/score/cpu/sparc/rtems/score/cpu.h
index d68b0c0..62c7b3c 100644
--- a/cpukit/score/cpu/sparc/rtems/score/cpu.h
+++ b/cpukit/score/cpu/sparc/rtems/score/cpu.h
@@ -1280,14 +1280,61 @@ static inline uint32_t CPU_swap_u32(
typedef uint32_t CPU_Counter_ticks;
-CPU_Counter_ticks _CPU_Counter_read( void );
+typedef CPU_Counter_ticks (*SPARC_Counter_difference)(
+ CPU_Counter_ticks second,
+ CPU_Counter_ticks first
+);
+
+/*
+ * The SPARC processors supported by RTEMS have no built-in CPU counter
+ * support. We have to use some hardware counter module for this purpose. The
+ * BSP must provide a 32-bit register which contains the current CPU counter
+ * value and a function for the difference calculation. It can use for example
+ * the GPTIMER instance used for the clock driver.
+ */
+typedef struct {
+ volatile const CPU_Counter_ticks *counter_register;
+ SPARC_Counter_difference counter_difference;
+} SPARC_Counter;
+
+extern SPARC_Counter _SPARC_Counter;
+
+/*
+ * Returns always a value of one regardless of the parameters. This prevents
+ * an infinite loop in rtems_counter_delay_ticks(). Its only a reasonably safe
+ * default.
+ */
+CPU_Counter_ticks _SPARC_Counter_difference_default(
+ CPU_Counter_ticks second,
+ CPU_Counter_ticks first
+);
+
+static inline bool _SPARC_Counter_is_default( void )
+{
+ return _SPARC_Counter.counter_difference
+ == _SPARC_Counter_difference_default;
+}
+
+static inline void _SPARC_Counter_initialize(
+ volatile const CPU_Counter_ticks *counter_register,
+ SPARC_Counter_difference counter_difference
+)
+{
+ _SPARC_Counter.counter_register = counter_register;
+ _SPARC_Counter.counter_difference = counter_difference;
+}
+
+static inline CPU_Counter_ticks _CPU_Counter_read( void )
+{
+ return *_SPARC_Counter.counter_register;
+}
static inline CPU_Counter_ticks _CPU_Counter_difference(
CPU_Counter_ticks second,
CPU_Counter_ticks first
)
{
- return second - first;
+ return (*_SPARC_Counter.counter_difference)( second, first );
}
#endif /* ASM */
diff --git a/cpukit/score/cpu/sparc/sparc-counter.c b/cpukit/score/cpu/sparc/sparc-counter.c
new file mode 100644
index 0000000..dc69b6b
--- /dev/null
+++ b/cpukit/score/cpu/sparc/sparc-counter.c
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2014 embedded brains GmbH. All rights reserved.
+ *
+ * embedded brains GmbH
+ * Dornierstr. 4
+ * 82178 Puchheim
+ * Germany
+ * <rtems at embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.com/license/LICENSE.
+ */
+
+#if HAVE_CONFIG_H
+ #include "config.h"
+#endif
+
+#include <rtems/score/cpu.h>
+
+static CPU_Counter_ticks _SPARC_Counter_register_dummy;
+
+CPU_Counter_ticks _SPARC_Counter_difference_default(
+ CPU_Counter_ticks second,
+ CPU_Counter_ticks first
+)
+{
+ return 1;
+}
+
+SPARC_Counter _SPARC_Counter = {
+ .counter_register = &_SPARC_Counter_register_dummy,
+ .counter_difference = _SPARC_Counter_difference_default
+};
--
1.7.7
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