将进程同步原语移动到common文件夹下

kernel/common/spinlock.h

@@ -0,0 +1,168 @@
+/**
+ * @file spinlock.h
+ * @author fslongjin (longjin@RinGoTek.cn)
+ * @brief 自旋锁
+ * @version 0.1
+ * @date 2022-04-07
+ *
+ * @copyright Copyright (c) 2022
+ *
+ */
+#pragma once
+#include <common/glib.h>
+#include <process/preempt.h>
+
+/**
+ * @brief 定义自旋锁结构体
+ *
+ */
+typedef struct
+{
+    __volatile__ char lock; // 1:unlocked 0:locked
+} spinlock_t;
+
+/**
+ * @brief 初始化自旋锁
+ *
+ * @param lock
+ */
+void spin_init(spinlock_t *lock)
+{
+    lock->lock = 1;
+}
+
+/**
+ * @brief 自旋锁加锁
+ *
+ * @param lock
+ */
+void spin_lock(spinlock_t *lock)
+{
+    __asm__ __volatile__("1:    \n\t"
+                         "lock decq %0   \n\t" // 尝试-1
+                         "jns 3f    \n\t"      // 加锁成功，跳转到步骤3
+                         "2:    \n\t"          // 加锁失败，稍后再试
+                         "pause \n\t"
+                         "cmpq $0, %0   \n\t"
+                         "jle   2b  \n\t" // 若锁被占用，则继续重试
+                         "jmp 1b    \n\t" // 尝试加锁
+                         "3:"
+                         : "=m"(lock->lock)::"memory");
+    preempt_disable();
+}
+
+/**
+ * @brief 自旋锁解锁
+ * 
+ * @param lock 
+ */
+void spin_unlock(spinlock_t *lock)
+{
+    preempt_enable();
+    __asm__ __volatile__("movq $1, %0   \n\t"
+                         : "=m"(lock->lock)::"memory");
+}
+
+/**
+ * @brief 自旋锁加锁（不改变自旋锁持有计数）
+ * 
+ * @warning 慎用此函数，除非你有十足的把握不会产生自旋锁计数错误
+ */
+void spin_lock_no_preempt(spinlock_t *lock)
+{
+     __asm__ __volatile__("1:    \n\t"
+                         "lock decq %0   \n\t" // 尝试-1
+                         "jns 3f    \n\t"      // 加锁成功，跳转到步骤3
+                         "2:    \n\t"          // 加锁失败，稍后再试
+                         "pause \n\t"
+                         "cmpq $0, %0   \n\t"
+                         "jle   2b  \n\t" // 若锁被占用，则继续重试
+                         "jmp 1b    \n\t" // 尝试加锁
+                         "3:"
+                         : "=m"(lock->lock)::"memory");
+}
+/**
+ * @brief 自旋锁解锁（不改变自旋锁持有计数）
+ * 
+ * @warning 慎用此函数，除非你有十足的把握不会产生自旋锁计数错误
+ */
+void spin_unlock_no_preempt(spinlock_t * lock)
+{
+    __asm__ __volatile__("movq $1, %0   \n\t"
+                         : "=m"(lock->lock)::"memory");
+}
+
+
+
+/**
+ * @brief 尝试加锁
+ *
+ * @param lock
+ * @return long 锁变量的值（1为成功加锁，0为加锁失败）
+ */
+long spin_trylock(spinlock_t *lock)
+{
+    uint64_t tmp_val = 0;
+    preempt_disable();
+    // 交换tmp_val和lock的值，若tmp_val==1则证明加锁成功
+    asm volatile("lock xchgq %0, %1  \n\t" // 确保只有1个进程能得到锁
+                 : "=q"(tmp_val), "=m"(lock->lock)
+                 : "0"(0)
+                 : "memory");
+    if (!tmp_val)
+        preempt_enable();
+    return tmp_val;
+}
+
+// 保存当前rflags的值到变量x内并关闭中断
+#define local_irq_save(x) __asm__ __volatile__("pushfq ; popq %0 ; cli" \
+                                               : "=g"(x)::"memory")
+// 恢复先前保存的rflags的值x
+#define local_irq_restore(x) __asm__ __volatile__("pushq %0 ; popfq" ::"g"(x) \
+                                                  : "memory")
+#define local_irq_disable() cli();
+#define local_irq_enable() sti();
+
+/**
+ * @brief 保存中断状态，关闭中断，并自旋锁加锁
+ * 
+ */
+#define spin_lock_irqsave(lock, flags) \
+    do                                 \
+    {                                  \
+        local_irq_save(flags);         \
+        spin_lock(lock);               \
+    } while (0)
+
+/**
+ * @brief 恢复rflags以及中断状态并解锁自旋锁
+ * 
+ */
+#define spin_unlock_irqrestore(lock, flags) \
+    do                                      \
+    {                                       \
+        spin_unlock(lock);                  \
+        local_irq_restore(flags);           \
+    } while (0)
+
+/**
+ * @brief 关闭中断并加锁
+ * 
+ */
+#define spin_lock_irq(lock)  \
+    do                       \
+    {                        \
+        local_irq_disable(); \
+        spin_lock(lock);     \
+    } while (0)
+
+/**
+ * @brief 解锁并开启中断
+ * 
+ */
+#define spin_unlock_irq(lock) \
+    do                        \
+    {                         \
+        spin_unlock(lock);    \
+        local_irq_enable();   \
+    } while (0)