nios2: Process management
This patch adds support for thread creation and context switching.
Signed-off-by: Ley Foon Tan <lftan@altera.com>
diff --git a/arch/nios2/include/asm/processor.h b/arch/nios2/include/asm/processor.h
new file mode 100644
index 0000000..3bd3494
--- /dev/null
+++ b/arch/nios2/include/asm/processor.h
@@ -0,0 +1,103 @@
+/*
+ * Copyright (C) 2013 Altera Corporation
+ * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
+ * Copyright (C) 2004 Microtronix Datacom Ltd
+ * Copyright (C) 2001 Ken Hill (khill@microtronix.com)
+ * Vic Phillips (vic@microtronix.com)
+ *
+ * based on SPARC asm/processor_32.h which is:
+ *
+ * Copyright (C) 1994 David S. Miller
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#ifndef _ASM_NIOS2_PROCESSOR_H
+#define _ASM_NIOS2_PROCESSOR_H
+
+#include <asm/ptrace.h>
+#include <asm/registers.h>
+#include <asm/page.h>
+
+#define NIOS2_FLAG_KTHREAD 0x00000001 /* task is a kernel thread */
+
+#define NIOS2_OP_NOP 0x1883a
+#define NIOS2_OP_BREAK 0x3da03a
+
+#ifdef __KERNEL__
+
+#define STACK_TOP TASK_SIZE
+#define STACK_TOP_MAX STACK_TOP
+
+#endif /* __KERNEL__ */
+
+/* Kuser helpers is mapped to this user space address */
+#define KUSER_BASE 0x1000
+#define KUSER_SIZE (PAGE_SIZE)
+#ifndef __ASSEMBLY__
+
+/*
+ * Default implementation of macro that returns current
+ * instruction pointer ("program counter").
+ */
+#define current_text_addr() ({ __label__ _l; _l: &&_l; })
+
+# define TASK_SIZE 0x7FFF0000UL
+# define TASK_UNMAPPED_BASE (PAGE_ALIGN(TASK_SIZE / 3))
+
+/* The Nios processor specific thread struct. */
+struct thread_struct {
+ struct pt_regs *kregs;
+
+ /* Context switch saved kernel state. */
+ unsigned long ksp;
+ unsigned long kpsr;
+};
+
+#define INIT_MMAP \
+ { &init_mm, (0), (0), __pgprot(0x0), VM_READ | VM_WRITE | VM_EXEC }
+
+# define INIT_THREAD { \
+ .kregs = NULL, \
+ .ksp = 0, \
+ .kpsr = 0, \
+}
+
+extern void start_thread(struct pt_regs *regs, unsigned long pc,
+ unsigned long sp);
+
+struct task_struct;
+
+/* Free all resources held by a thread. */
+static inline void release_thread(struct task_struct *dead_task)
+{
+}
+
+/* Free current thread data structures etc.. */
+static inline void exit_thread(void)
+{
+}
+
+/* Return saved PC of a blocked thread. */
+#define thread_saved_pc(tsk) ((tsk)->thread.kregs->ea)
+
+extern unsigned long get_wchan(struct task_struct *p);
+
+/* Prepare to copy thread state - unlazy all lazy status */
+#define prepare_to_copy(tsk) do { } while (0)
+
+#define task_pt_regs(p) \
+ ((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
+
+/* Used by procfs */
+#define KSTK_EIP(tsk) ((tsk)->thread.kregs->ea)
+#define KSTK_ESP(tsk) ((tsk)->thread.kregs->sp)
+
+#define cpu_relax() barrier()
+#define cpu_relax_lowlatency() cpu_relax()
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _ASM_NIOS2_PROCESSOR_H */