RT-Thread_v4.1.1

libcpu/arm/cortex-a/cpu.c

@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) 2006-2021, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2011-09-15     Bernard      first version
+ * 2018-11-22     Jesven       add rt_hw_cpu_id()
+ */
+
+#include <rthw.h>
+#include <rtthread.h>
+#include <board.h>
+
+#ifdef RT_USING_SMP
+
+void rt_hw_spin_lock_init(rt_hw_spinlock_t *lock)
+{
+    lock->slock = 0;
+}
+
+void rt_hw_spin_lock(rt_hw_spinlock_t *lock)
+{
+    unsigned long tmp;
+    unsigned long newval;
+    rt_hw_spinlock_t lockval;
+
+    __asm__ __volatile__(
+            "pld [%0]"
+            ::"r"(&lock->slock)
+            );
+
+    __asm__ __volatile__(
+            "1: ldrex   %0, [%3]\n"
+            "   add %1, %0, %4\n"
+            "   strex   %2, %1, [%3]\n"
+            "   teq %2, #0\n"
+            "   bne 1b"
+            : "=&r" (lockval), "=&r" (newval), "=&r" (tmp)
+            : "r" (&lock->slock), "I" (1 << 16)
+            : "cc");
+
+    while (lockval.tickets.next != lockval.tickets.owner) {
+        __asm__ __volatile__("wfe":::"memory");
+        lockval.tickets.owner = *(volatile unsigned short *)(&lock->tickets.owner);
+    }
+
+    __asm__ volatile ("dmb":::"memory");
+}
+
+void rt_hw_spin_unlock(rt_hw_spinlock_t *lock)
+{
+    __asm__ volatile ("dmb":::"memory");
+    lock->tickets.owner++;
+    __asm__ volatile ("dsb ishst\nsev":::"memory");
+}
+#endif /*RT_USING_SMP*/
+
+/**
+ * @addtogroup ARM CPU
+ */
+/*@{*/
+
+/** shutdown CPU */
+RT_WEAK void rt_hw_cpu_shutdown()
+{
+    rt_base_t level;
+    rt_kprintf("shutdown...\n");
+
+    level = rt_hw_interrupt_disable();
+    while (level)
+    {
+        RT_ASSERT(0);
+    }
+}
+
+#ifdef RT_USING_CPU_FFS
+/**
+ * This function finds the first bit set (beginning with the least significant bit)
+ * in value and return the index of that bit.
+ *
+ * Bits are numbered starting at 1 (the least significant bit).  A return value of
+ * zero from any of these functions means that the argument was zero.
+ *
+ * @return return the index of the first bit set. If value is 0, then this function
+ * shall return 0.
+ */
+int __rt_ffs(int value)
+{
+    return __builtin_ffs(value);
+}
+#endif
+
+/*@}*/