unicore32 core architecture: process/thread related codes

This patch implements process/thread related codes. Backtrace and stacktrace are here.

Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>

arch/unicore32/include/asm/stacktrace.h

@@ -0,0 +1,31 @@
+/*
+ * linux/arch/unicore32/include/asm/stacktrace.h
+ *
+ * Code specific to PKUnity SoC and UniCore ISA
+ *
+ * Copyright (C) 2001-2010 GUAN Xue-tao
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __UNICORE_STACKTRACE_H__
+#define __UNICORE_STACKTRACE_H__
+
+struct stackframe {
+	unsigned long fp;
+	unsigned long sp;
+	unsigned long lr;
+	unsigned long pc;
+};
+
+#ifdef CONFIG_FRAME_POINTER
+extern int unwind_frame(struct stackframe *frame);
+#else
+#define unwind_frame(f) (-EINVAL)
+#endif
+extern void walk_stackframe(struct stackframe *frame,
+			    int (*fn)(struct stackframe *, void *), void *data);
+
+#endif	/* __UNICORE_STACKTRACE_H__ */

arch/unicore32/include/asm/thread_info.h

@@ -0,0 +1,154 @@
+/*
+ * linux/arch/unicore32/include/asm/thread_info.h
+ *
+ * Code specific to PKUnity SoC and UniCore ISA
+ *
+ * Copyright (C) 2001-2010 GUAN Xue-tao
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef __UNICORE_THREAD_INFO_H__
+#define __UNICORE_THREAD_INFO_H__
+
+#ifdef __KERNEL__
+
+#include <linux/compiler.h>
+#include <asm/fpstate.h>
+
+#define THREAD_SIZE_ORDER	1
+#define THREAD_SIZE		8192
+#define THREAD_START_SP		(THREAD_SIZE - 8)
+
+#ifndef __ASSEMBLY__
+
+struct task_struct;
+struct exec_domain;
+
+#include <asm/types.h>
+
+typedef struct {
+	unsigned long seg;
+} mm_segment_t;
+
+struct cpu_context_save {
+	__u32	r4;
+	__u32	r5;
+	__u32	r6;
+	__u32	r7;
+	__u32	r8;
+	__u32	r9;
+	__u32	r10;
+	__u32	r11;
+	__u32	r12;
+	__u32	r13;
+	__u32	r14;
+	__u32	r15;
+	__u32	r16;
+	__u32	r17;
+	__u32	r18;
+	__u32	r19;
+	__u32	r20;
+	__u32	r21;
+	__u32	r22;
+	__u32	r23;
+	__u32	r24;
+	__u32	r25;
+	__u32	r26;
+	__u32	fp;
+	__u32	sp;
+	__u32	pc;
+};
+
+/*
+ * low level task data that entry.S needs immediate access to.
+ * __switch_to() assumes cpu_context follows immediately after cpu_domain.
+ */
+struct thread_info {
+	unsigned long		flags;		/* low level flags */
+	int			preempt_count;	/* 0 => preemptable */
+						/* <0 => bug */
+	mm_segment_t		addr_limit;	/* address limit */
+	struct task_struct	*task;		/* main task structure */
+	struct exec_domain	*exec_domain;	/* execution domain */
+	__u32			cpu;		/* cpu */
+	struct cpu_context_save	cpu_context;	/* cpu context */
+	__u32			syscall;	/* syscall number */
+	__u8			used_cp[16];	/* thread used copro */
+#ifdef CONFIG_UNICORE_FPU_F64
+	struct fp_state		fpstate __attribute__((aligned(8)));
+#endif
+	struct restart_block	restart_block;
+};
+
+#define INIT_THREAD_INFO(tsk)						\
+{									\
+	.task		= &tsk,						\
+	.exec_domain	= &default_exec_domain,				\
+	.flags		= 0,						\
+	.preempt_count	= INIT_PREEMPT_COUNT,				\
+	.addr_limit	= KERNEL_DS,					\
+	.restart_block	= {						\
+		.fn	= do_no_restart_syscall,			\
+	},								\
+}
+
+#define init_thread_info	(init_thread_union.thread_info)
+#define init_stack		(init_thread_union.stack)
+
+/*
+ * how to get the thread information struct from C
+ */
+static inline struct thread_info *current_thread_info(void) __attribute_const__;
+
+static inline struct thread_info *current_thread_info(void)
+{
+	register unsigned long sp asm ("sp");
+	return (struct thread_info *)(sp & ~(THREAD_SIZE - 1));
+}
+
+#define thread_saved_pc(tsk)	\
+	((unsigned long)(task_thread_info(tsk)->cpu_context.pc))
+#define thread_saved_sp(tsk)	\
+	((unsigned long)(task_thread_info(tsk)->cpu_context.sp))
+#define thread_saved_fp(tsk)	\
+	((unsigned long)(task_thread_info(tsk)->cpu_context.fp))
+
+#endif
+
+/*
+ * We use bit 30 of the preempt_count to indicate that kernel
+ * preemption is occurring.  See <asm/hardirq.h>.
+ */
+#define PREEMPT_ACTIVE	0x40000000
+
+/*
+ * thread information flags:
+ *  TIF_SYSCALL_TRACE	- syscall trace active
+ *  TIF_SIGPENDING	- signal pending
+ *  TIF_NEED_RESCHED	- rescheduling necessary
+ *  TIF_NOTIFY_RESUME	- callback before returning to user
+ */
+#define TIF_SIGPENDING		0
+#define TIF_NEED_RESCHED	1
+#define TIF_NOTIFY_RESUME	2	/* callback before returning to user */
+#define TIF_SYSCALL_TRACE	8
+#define TIF_MEMDIE		18
+#define TIF_FREEZE		19
+#define TIF_RESTORE_SIGMASK	20
+
+#define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
+#define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
+#define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
+#define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
+#define _TIF_FREEZE		(1 << TIF_FREEZE)
+#define _TIF_RESTORE_SIGMASK	(1 << TIF_RESTORE_SIGMASK)
+
+/*
+ * Change these and you break ASM code in entry-common.S
+ */
+#define _TIF_WORK_MASK		0x000000ff
+
+#endif /* __KERNEL__ */
+#endif /* __UNICORE_THREAD_INFO_H__ */

arch/unicore32/kernel/init_task.c

@@ -0,0 +1,44 @@
+/*
+ * linux/arch/unicore32/kernel/init_task.c
+ *
+ * Code specific to PKUnity SoC and UniCore ISA
+ *
+ * Copyright (C) 2001-2010 GUAN Xue-tao
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/init_task.h>
+#include <linux/mqueue.h>
+#include <linux/uaccess.h>
+
+#include <asm/pgtable.h>
+
+static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
+static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
+/*
+ * Initial thread structure.
+ *
+ * We need to make sure that this is 8192-byte aligned due to the
+ * way process stacks are handled. This is done by making sure
+ * the linker maps this in the .text segment right after head.S,
+ * and making head.S ensure the proper alignment.
+ *
+ * The things we do for performance..
+ */
+union thread_union init_thread_union __init_task_data = {
+	INIT_THREAD_INFO(init_task) };
+
+/*
+ * Initial task structure.
+ *
+ * All other task structs will be allocated on slabs in fork.c
+ */
+struct task_struct init_task = INIT_TASK(init_task);
+EXPORT_SYMBOL(init_task);