1 files changed, 105 insertions, 0 deletions

diff --git a/include/litmus/fp_common.h b/include/litmus/fp_common.h
new file mode 100644
index 000000000000..dd1f7bf1e347
--- /dev/null
+++ b/include/litmus/fp_common.h
@@ -0,0 +1,105 @@
+/* Fixed-priority scheduler support.
+ */
+
+#ifndef __FP_COMMON_H__
+#define __FP_COMMON_H__
+
+#include <litmus/rt_domain.h>
+
+#include <asm/bitops.h>
+
+
+void fp_domain_init(rt_domain_t* rt, check_resched_needed_t resched,
+                    release_jobs_t release);
+
+int fp_higher_prio(struct task_struct* first,
+                   struct task_struct* second);
+
+int fp_ready_order(struct bheap_node* a, struct bheap_node* b);
+
+#define FP_PRIO_BIT_WORDS (LITMUS_MAX_PRIORITY / BITS_PER_LONG)
+
+#if (LITMUS_MAX_PRIORITY % BITS_PER_LONG)
+#error LITMUS_MAX_PRIORITY must be a multiple of BITS_PER_LONG
+#endif
+
+/* bitmask-inexed priority queue */
+struct fp_prio_queue {
+        unsigned long   bitmask[FP_PRIO_BIT_WORDS];
+        struct bheap    queue[LITMUS_MAX_PRIORITY];
+};
+
+void fp_prio_queue_init(struct fp_prio_queue* q);
+
+static inline void fpq_set(struct fp_prio_queue* q, unsigned int index)
+{
+        unsigned long *word = q->bitmask + (index / BITS_PER_LONG);
+        __set_bit(index % BITS_PER_LONG, word);
+}
+
+static inline void fpq_clear(struct fp_prio_queue* q, unsigned int index)
+{
+        unsigned long *word = q->bitmask + (index / BITS_PER_LONG);
+        __clear_bit(index % BITS_PER_LONG, word);
+}
+
+static inline unsigned int fpq_find(struct fp_prio_queue* q)
+{
+        int i;
+
+        /* loop optimizer should unroll this */
+        for (i = 0; i < FP_PRIO_BIT_WORDS; i++)
+                if (q->bitmask[i])
+                        return __ffs(q->bitmask[i]) + i * BITS_PER_LONG;
+
+        return LITMUS_MAX_PRIORITY; /* nothing found */
+}
+
+static inline void fp_prio_add(struct fp_prio_queue* q, struct task_struct* t, unsigned int index)
+{
+
+        BUG_ON(bheap_node_in_heap(tsk_rt(t)->heap_node));
+
+        fpq_set(q, index);
+        bheap_insert(fp_ready_order, &q->queue[index], tsk_rt(t)->heap_node);
+}
+
+static inline void fp_prio_remove(struct fp_prio_queue* q, struct task_struct* t, unsigned int index)
+{
+        BUG_ON(!is_queued(t));
+
+        bheap_delete(fp_ready_order, &q->queue[index], tsk_rt(t)->heap_node);
+        if (likely(bheap_empty(&q->queue[index])))
+                fpq_clear(q, index);
+}
+
+static inline struct task_struct* fp_prio_peek(struct fp_prio_queue* q)
+{
+        unsigned int idx = fpq_find(q);
+        struct bheap_node* hn;
+
+        if (idx < LITMUS_MAX_PRIORITY) {
+                hn = bheap_peek(fp_ready_order, &q->queue[idx]);
+                return bheap2task(hn);
+        } else
+                return NULL;
+}
+
+static inline struct task_struct* fp_prio_take(struct fp_prio_queue* q)
+{
+        unsigned int idx = fpq_find(q);
+        struct bheap_node* hn;
+
+        if (idx < LITMUS_MAX_PRIORITY) {
+                hn = bheap_take(fp_ready_order, &q->queue[idx]);
+                if (likely(bheap_empty(&q->queue[idx])))
+                        fpq_clear(q, idx);
+                return bheap2task(hn);
+        } else
+                return NULL;
+}
+
+int fp_preemption_needed(struct fp_prio_queue*  q, struct task_struct *t);
+
+
+#endif