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authorSebastian Huber <sebastian.huber@embedded-brains.de>2018-04-20 13:38:33 +0200
committerSebastian Huber <sebastian.huber@embedded-brains.de>2018-04-20 14:32:43 +0200
commit1efa1c8389604dcf303b9acfa26c0ae60db9d9b4 (patch)
tree0fe569d6ad62623bf820f1dcd3620227995fae75 /bsps/sparc/leon3/mpci/lock.c
parentbsps/sparc: Move network drivers to bsps (diff)
downloadrtems-1efa1c8389604dcf303b9acfa26c0ae60db9d9b4.tar.bz2
bsps: Move MPCI support to bsps
This patch is a part of the BSP source reorganization. Update #3285.
Diffstat (limited to 'bsps/sparc/leon3/mpci/lock.c')
-rw-r--r--bsps/sparc/leon3/mpci/lock.c90
1 files changed, 90 insertions, 0 deletions
diff --git a/bsps/sparc/leon3/mpci/lock.c b/bsps/sparc/leon3/mpci/lock.c
new file mode 100644
index 0000000000..5b118f24b6
--- /dev/null
+++ b/bsps/sparc/leon3/mpci/lock.c
@@ -0,0 +1,90 @@
+/**
+ * @file
+ *
+ * LEON3 Shared Memory Lock Routines
+ *
+ * This shared memory locked queue support routine need to be
+ * able to lock the specified locked queue. Interrupts are
+ * disabled while the queue is locked to prevent preemption
+ * and deadlock when two tasks poll for the same lock.
+ * previous level.
+ */
+
+/*
+ * COPYRIGHT (c) 1989-2012.
+ * On-Line Applications Research Corporation (OAR).
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.org/license/LICENSE.
+ */
+
+#include <rtems.h>
+#include <bsp.h>
+#include <shm_driver.h>
+
+
+/*
+ * Initialize the lock for the specified locked queue.
+ */
+void Shm_Initialize_lock(
+ Shm_Locked_queue_Control *lq_cb
+)
+{
+ lq_cb->lock = LQ_UNLOCKED;
+}
+
+/*
+ * This shared memory locked queue support routine locks the
+ * specified locked queue. It disables interrupts to prevent
+ * a deadlock condition.
+ */
+extern unsigned int LEON3_Atomic_Swap(uint32_t value, uint32_t *address);
+
+__asm__ (
+ ".text\n"
+ ".align 4\n"
+ "LEON3_Atomic_Swap:\n"
+ " retl\n"
+ " swapa [%o1] 1, %o0\n"
+);
+
+
+
+void Shm_Lock(
+ Shm_Locked_queue_Control *lq_cb
+)
+{
+ uint32_t isr_level;
+ uint32_t *lockptr = (uint32_t *) &lq_cb->lock;
+ uint32_t lock_value;
+
+ lock_value = SHM_LOCK_VALUE;
+ rtems_interrupt_disable( isr_level );
+
+ Shm_isrstat = isr_level;
+ while ( lock_value ) {
+ lock_value = LEON3_Atomic_Swap(lock_value, lockptr);
+ /*
+ * If not available, then may want to delay to reduce load on lock.
+ */
+ }
+}
+
+/*
+ * Shm_Unlock
+ *
+ * Unlock the lock for the specified locked queue.
+ */
+
+void Shm_Unlock(
+ Shm_Locked_queue_Control *lq_cb
+)
+{
+ uint32_t isr_level;
+
+ lq_cb->lock = SHM_UNLOCK_VALUE;
+ isr_level = Shm_isrstat;
+ rtems_interrupt_enable( isr_level );
+}
+