From 5a32c486f9b7bd8687af253931b47d7abb091bc3 Mon Sep 17 00:00:00 2001
From: Sebastian Huber <sebastian.huber@embedded-brains.de>
Date: Tue, 14 Jun 2016 15:57:54 +0200
Subject: posix: Make POSIX API aware of scheduler instances

---
 cpukit/posix/include/rtems/posix/priorityimpl.h | 85 ++++++++-----------------
 1 file changed, 28 insertions(+), 57 deletions(-)

(limited to 'cpukit/posix/include/rtems/posix/priorityimpl.h')

diff --git a/cpukit/posix/include/rtems/posix/priorityimpl.h b/cpukit/posix/include/rtems/posix/priorityimpl.h
index e3f23e748d..d06b600f04 100644
--- a/cpukit/posix/include/rtems/posix/priorityimpl.h
+++ b/cpukit/posix/include/rtems/posix/priorityimpl.h
@@ -30,29 +30,10 @@ extern "C" {
  *
  * @ingroup POSIXAPI
  *
- * @brief Interface to the POSIX Priority Implementation
- * 
- */
-/**@{**/
-
-/**
- * 1003.1b-1993,2.2.2.80 definition of priority, p. 19
- *
- * "Numerically higher values represent higher priorities."
- *
- * Thus, RTEMS Core has priorities run in the opposite sense of the POSIX API.
+ * @brief Interface to the POSIX Priority Implementation.
  *
- * There are only 254 posix priority levels since a task at priority level
- * 255 would never run because of the RTEMS idle task.  This is necessary
- * because GNAT maps the lowest Ada task priority to the lowest thread
- * priority.  The lowest priority Ada task should get to run, so there is
- * a fundamental conflict with having 255 priorities.
- *
- * But since RTEMS can be configured with fewer than 256 priorities,
- * we use the internal constant.
+ * @{
  */
-#define POSIX_SCHEDULER_MAXIMUM_PRIORITY (PRIORITY_MAXIMUM - 1)
-
 
 /**
  *  This is the numerically least important POSIX priority.
@@ -72,53 +53,43 @@ int _POSIX_Priority_Get_maximum( const Scheduler_Control *scheduler );
 /**
  * @brief Check if POSIX priority is valid.
  * 
- * 1003.1b-1993,2.2.2.80 definition of priority, p. 19
- *
- * "Numerically higher values represent higher priorities."
- *
- * Thus, RTEMS Core has priorities run in the opposite sense of the POSIX API.
- *
- * @param[in] priority is the priority to test
- *
- * @retval TRUE The priority is valid.
- * @retval FALSE The priority is invalid.
+ * According to POSIX, numerically higher values represent higher priorities.
+ * Thus, SuperCore has priorities run in the opposite sense of the POSIX API.
+ *
+ * Let N be the maximum priority of this scheduler instance.   The SuperCore
+ * priority zero is system reserved (PRIORITY_PSEUDO_ISR).  There are only
+ * N - 1 POSIX API priority levels since a thread at SuperCore priority N would
+ * never run because of the idle threads.  This is necessary because GNAT maps
+ * the lowest Ada task priority to the lowest thread priority.  The lowest
+ * priority Ada task should get to run, so there is a fundamental conflict with
+ * having N priorities.
+ *
+ * @param[in] scheduler The scheduler instance.
+ * @param[in] priority The POSIX API priority to test.
+ *
+ * @retval true The priority is valid.
+ * @retval false Otherwise.
  */
 bool _POSIX_Priority_Is_valid(
-  int priority
+  const Scheduler_Control *scheduler,
+  int                      priority
 );
 
 /**
- * @brief Convert POSIX priority to SuperCore priority.
- *
- * This method converts a POSIX API priority into onto the corresponding
- * SuperCore value.
- *
- * @param[in] priority is the POSIX API priority.
- *
- * @return This method returns the corresponding SuperCore priority.
- */
-RTEMS_INLINE_ROUTINE Priority_Control _POSIX_Priority_To_core(
-  int priority
-)
-{
-  return (Priority_Control) (POSIX_SCHEDULER_MAXIMUM_PRIORITY - priority + 1);
-}
-
-/**
- * @brief Convert SuperCore priority To POSIX priority.
- *
- * This method converts a SuperCore priority into onto the corresponding
- * POSIX API value.
+ * @brief Converts the SuperCore priority to the corresponding POSIX API
+ * priority.
  *
- * @param[in] priority is the POSIX API priority.
+ * @param[in] scheduler The scheduler instance.
+ * @param[in] priority The SuperCore priority to convert.
  *
- * @return This method returns the corresponding POSIX priority.
+ * @return The corresponding POSIX API priority.
  */
 RTEMS_INLINE_ROUTINE int _POSIX_Priority_From_core(
-  Priority_Control priority
+  const Scheduler_Control *scheduler,
+  Priority_Control         priority
 )
 {
-  return (POSIX_SCHEDULER_MAXIMUM_PRIORITY - priority + 1);
+  return (int) ( scheduler->maximum_priority - priority );
 }
 
 /** @} */
-- 
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