Squash commits for public release

kernel/include/syscalls/interruptible_area.h

@@ -0,0 +1,36 @@
+#ifndef _KERNEL_SYSCALLS_INTERRUPTIBLE_AREA_H
+#define _KERNEL_SYSCALLS_INTERRUPTIBLE_AREA_H
+
+#include <libkern/libkern.h>
+#include <platform/generic/system.h>
+#include <tasking/cpu.h>
+
+/**
+ * By design the whole kernel is not interruptible, but some parts inside kernel
+ * could be interrupted without any bad consequences and at the same time these
+ * parts take a lot of cpu time, like copying data from/to user. We might want
+ * to mark them as interruptible.
+ */
+
+static ALWAYS_INLINE int interruptible_area_start()
+{
+    int res = THIS_CPU->int_depth_counter;
+    THIS_CPU->int_depth_counter = 0;
+    system_enable_interrupts_no_counter();
+    return res;
+}
+
+static ALWAYS_INLINE int interruptible_area_end(int old)
+{
+    system_disable_interrupts_no_counter();
+    THIS_CPU->int_depth_counter = old;
+    return 0;
+}
+
+#ifdef PREEMPT_KERNEL
+#define INTERRUPTIBLE_AREA for (int __i = 0, __j = interruptible_area_start(); __i < 1; interruptible_area_end(__j), __i++)
+#else
+#define INTERRUPTIBLE_AREA if (true)
+#endif
+
+#endif // _KERNEL_SYSCALLS_INTERRUPTIBLE_AREA_H