nios2: Process management

/*

 * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>

 * Copyright (C) 1996, 1997, 1998, 1999 by Ralf Baechle

 * Copyright (C) 1999 Silicon Graphics, Inc.

 *

 * based on MIPS asm/mmu_context.h

 *

 * 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_MMU_CONTEXT_H

#define _ASM_NIOS2_MMU_CONTEXT_H

#include <asm-generic/mm_hooks.h>

extern void mmu_context_init(void);

extern unsigned long get_pid_from_context(mm_context_t *ctx);

/*

 * For the fast tlb miss handlers, we keep a pointer to the current pgd.

 * processor.

 */

extern pgd_t *pgd_current;

static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)

{

}

/*

 * Initialize the context related info for a new mm_struct instance.

 *

 * Set all new contexts to 0, that way the generation will never match

 * the currently running generation when this context is switched in.

 */

static inline int init_new_context(struct task_struct *tsk,

					struct mm_struct *mm)

{

	mm->context = 0;

	return 0;

}

/*

 * Destroy context related info for an mm_struct that is about

 * to be put to rest.

 */

static inline void destroy_context(struct mm_struct *mm)

{

}

void switch_mm(struct mm_struct *prev, struct mm_struct *next,

		struct task_struct *tsk);

static inline void deactivate_mm(struct task_struct *tsk,

				struct mm_struct *mm)

{

}

/*

 * After we have set current->mm to a new value, this activates

 * the context for the new mm so we see the new mappings.

 */

void activate_mm(struct mm_struct *prev, struct mm_struct *next);

#endif /* _ASM_NIOS2_MMU_CONTEXT_H */

/*

 * 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 */

/*

 * Copyright (C) 2004 Microtronix Datacom Ltd.

 *

 * 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_SWITCH_TO_H

#define _ASM_NIOS2_SWITCH_TO_H

/*

 * switch_to(n) should switch tasks to task ptr, first checking that

 * ptr isn't the current task, in which case it does nothing.  This

 * also clears the TS-flag if the task we switched to has used the

 * math co-processor latest.

 */

#define switch_to(prev, next, last)			\

{							\

	void *_last;					\

	__asm__ __volatile__ (				\

		"mov	r4, %1\n"			\

		"mov	r5, %2\n"			\

		"call	resume\n"			\

		"mov	%0,r4\n"			\

		: "=r" (_last)				\

		: "r" (prev), "r" (next)		\

		: "r4", "r5", "r7", "r8", "ra");	\

	(last) = _last;					\

}

#endif /* _ASM_NIOS2_SWITCH_TO_H */

/*

 * NiosII low-level thread information

 *

 * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>

 * Copyright (C) 2004 Microtronix Datacom Ltd.

 *

 * Based on asm/thread_info_no.h from m68k which is:

 *

 * Copyright (C) 2002 David Howells <dhowells@redhat.com>

 *

 * 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_THREAD_INFO_H

#define _ASM_NIOS2_THREAD_INFO_H

#ifdef __KERNEL__

/*

 * Size of the kernel stack for each process.

 */

#define THREAD_SIZE_ORDER	1

#define THREAD_SIZE		8192 /* 2 * PAGE_SIZE */

#ifndef __ASSEMBLY__

typedef struct {

	unsigned long seg;

} mm_segment_t;

/*

 * low level task data that entry.S needs immediate access to

 * - this struct should fit entirely inside of one cache line

 * - this struct shares the supervisor stack pages

 * - if the contents of this structure are changed, the assembly constants

 *   must also be changed

 */

struct thread_info {

	struct task_struct	*task;		/* main task structure */

	struct exec_domain	*exec_domain;	/* execution domain */

	unsigned long		flags;		/* low level flags */

	__u32			cpu;		/* current CPU */

	int			preempt_count;	/* 0 => preemptable,<0 => BUG */

	mm_segment_t		addr_limit;	/* thread address space:

						  0-0x7FFFFFFF for user-thead

						  0-0xFFFFFFFF for kernel-thread

						*/

	struct restart_block	restart_block;

	struct pt_regs		*regs;

};

/*

 * macros/functions for gaining access to the thread information structure

 *

 * preempt_count needs to be 1 initially, until the scheduler is functional.

 */

#define INIT_THREAD_INFO(tsk)			\

{						\

	.task		= &tsk,			\

	.exec_domain	= &default_exec_domain,	\

	.flags		= 0,			\

	.cpu		= 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)

{

	register unsigned long sp asm("sp");

	return (struct thread_info *)(sp & ~(THREAD_SIZE - 1));

}

#endif /* !__ASSEMBLY__ */

/*

 * thread information flags

 * - these are process state flags that various assembly files may need to

 *   access

 * - pending work-to-be-done flags are in LSW

 * - other flags in MSW

 */

#define TIF_SYSCALL_TRACE	0	/* syscall trace active */

#define TIF_NOTIFY_RESUME	1	/* resumption notification requested */

#define TIF_SIGPENDING		2	/* signal pending */

#define TIF_NEED_RESCHED	3	/* rescheduling necessary */

#define TIF_MEMDIE		4	/* is terminating due to OOM killer */

#define TIF_SECCOMP		5	/* secure computing */

#define TIF_SYSCALL_AUDIT	6	/* syscall auditing active */

#define TIF_RESTORE_SIGMASK	9	/* restore signal mask in do_signal() */

#define TIF_POLLING_NRFLAG	16	/* true if poll_idle() is polling

					   TIF_NEED_RESCHED */

#define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)

#define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)

#define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)

#define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)

#define _TIF_SECCOMP		(1 << TIF_SECCOMP)

#define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)

#define _TIF_RESTORE_SIGMASK	(1 << TIF_RESTORE_SIGMASK)

#define _TIF_POLLING_NRFLAG	(1 << TIF_POLLING_NRFLAG)

/* work to do on interrupt/exception return */

#define _TIF_WORK_MASK		0x0000FFFE

/* work to do on any return to u-space */

# define _TIF_ALLWORK_MASK	0x0000FFFF

#endif /* __KERNEL__ */

#endif /* _ASM_NIOS2_THREAD_INFO_H */

/*

 * Architecture-dependent parts of process handling.

 *

 * Copyright (C) 2013 Altera Corporation

 * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>

 * Copyright (C) 2009 Wind River Systems Inc

 *   Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com

 * Copyright (C) 2004 Microtronix Datacom Ltd

 *

 * 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.

 */

#include <linux/export.h>

#include <linux/sched.h>

#include <linux/tick.h>

#include <linux/uaccess.h>

#include <asm/unistd.h>

#include <asm/traps.h>

#include <asm/cpuinfo.h>

asmlinkage void ret_from_fork(void);

asmlinkage void ret_from_kernel_thread(void);

void (*pm_power_off)(void) = NULL;

EXPORT_SYMBOL(pm_power_off);

void arch_cpu_idle(void)

{

	local_irq_enable();

}

/*

 * The development boards have no way to pull a board reset. Just jump to the

 * cpu reset address and let the boot loader or the code in head.S take care of

 * resetting peripherals.

 */

void machine_restart(char *__unused)

{

	pr_notice("Machine restart (%08x)...\n", cpuinfo.reset_addr);

	local_irq_disable();

	__asm__ __volatile__ (

	"jmp	%0\n\t"

	:

	: "r" (cpuinfo.reset_addr)

	: "r4");

}

void machine_halt(void)

{

	pr_notice("Machine halt...\n");

	local_irq_disable();

	for (;;)

		;

}

/*

 * There is no way to power off the development boards. So just spin for now. If

 * we ever have a way of resetting a board using a GPIO we should add that here.

 */

void machine_power_off(void)

{

	pr_notice("Machine power off...\n");

	local_irq_disable();

	for (;;)

		;

}

void show_regs(struct pt_regs *regs)

{

	pr_notice("\n");

	show_regs_print_info(KERN_DEFAULT);

	pr_notice("r1: %08lx r2: %08lx r3: %08lx r4: %08lx\n",

		regs->r1,  regs->r2,  regs->r3,  regs->r4);

	pr_notice("r5: %08lx r6: %08lx r7: %08lx r8: %08lx\n",

		regs->r5,  regs->r6,  regs->r7,  regs->r8);

	pr_notice("r9: %08lx r10: %08lx r11: %08lx r12: %08lx\n",

		regs->r9,  regs->r10, regs->r11, regs->r12);

	pr_notice("r13: %08lx r14: %08lx r15: %08lx\n",

		regs->r13, regs->r14, regs->r15);

	pr_notice("ra: %08lx fp:  %08lx sp: %08lx gp: %08lx\n",

		regs->ra,  regs->fp,  regs->sp,  regs->gp);

	pr_notice("ea: %08lx estatus: %08lx\n",

		regs->ea,  regs->estatus);

}

void flush_thread(void)

{

	set_fs(USER_DS);

}

int copy_thread(unsigned long clone_flags,

		unsigned long usp, unsigned long arg, struct task_struct *p)

{

	struct pt_regs *childregs = task_pt_regs(p);

	struct pt_regs *regs;

	struct switch_stack *stack;

	struct switch_stack *childstack =

		((struct switch_stack *)childregs) - 1;

	if (unlikely(p->flags & PF_KTHREAD)) {

		memset(childstack, 0,

			sizeof(struct switch_stack) + sizeof(struct pt_regs));

		childstack->r16 = usp;		/* fn */

		childstack->r17 = arg;

		childstack->ra = (unsigned long) ret_from_kernel_thread;

		childregs->estatus = STATUS_PIE;

		childregs->sp = (unsigned long) childstack;

		p->thread.ksp = (unsigned long) childstack;

		p->thread.kregs = childregs;

		return 0;

	}

	regs = current_pt_regs();

	*childregs = *regs;

	childregs->r2 = 0;	/* Set the return value for the child. */

	childregs->r7 = 0;

	stack = ((struct switch_stack *) regs) - 1;

	*childstack = *stack;

	childstack->ra = (unsigned long)ret_from_fork;

	p->thread.kregs = childregs;

	p->thread.ksp = (unsigned long) childstack;

	if (usp)

		childregs->sp = usp;

	/* Initialize tls register. */

	if (clone_flags & CLONE_SETTLS)

		childstack->r23 = regs->r8;

	return 0;

}

/*

 *	Generic dumping code. Used for panic and debug.

 */

void dump(struct pt_regs *fp)

{

	unsigned long	*sp;

	unsigned char	*tp;

	int		i;

	pr_emerg("\nCURRENT PROCESS:\n\n");

	pr_emerg("COMM=%s PID=%d\n", current->comm, current->pid);

	if (current->mm) {

		pr_emerg("TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",

			(int) current->mm->start_code,

			(int) current->mm->end_code,

			(int) current->mm->start_data,

			(int) current->mm->end_data,

			(int) current->mm->end_data,

			(int) current->mm->brk);

		pr_emerg("USER-STACK=%08x  KERNEL-STACK=%08x\n\n",

			(int) current->mm->start_stack,

			(int)(((unsigned long) current) + THREAD_SIZE));

	}

	pr_emerg("PC: %08lx\n", fp->ea);

	pr_emerg("SR: %08lx    SP: %08lx\n",

		(long) fp->estatus, (long) fp);

	pr_emerg("r1: %08lx    r2: %08lx    r3: %08lx\n",

		fp->r1, fp->r2, fp->r3);

	pr_emerg("r4: %08lx    r5: %08lx    r6: %08lx    r7: %08lx\n",

		fp->r4, fp->r5, fp->r6, fp->r7);

	pr_emerg("r8: %08lx    r9: %08lx    r10: %08lx    r11: %08lx\n",

		fp->r8, fp->r9, fp->r10, fp->r11);

	pr_emerg("r12: %08lx  r13: %08lx    r14: %08lx    r15: %08lx\n",

		fp->r12, fp->r13, fp->r14, fp->r15);

	pr_emerg("or2: %08lx   ra: %08lx     fp: %08lx    sp: %08lx\n",

		fp->orig_r2, fp->ra, fp->fp, fp->sp);

	pr_emerg("\nUSP: %08x   TRAPFRAME: %08x\n",

		(unsigned int) fp->sp, (unsigned int) fp);

	pr_emerg("\nCODE:");

	tp = ((unsigned char *) fp->ea) - 0x20;

	for (sp = (unsigned long *) tp, i = 0; (i < 0x40);  i += 4) {

		if ((i % 0x10) == 0)

			pr_emerg("\n%08x: ", (int) (tp + i));

		pr_emerg("%08x ", (int) *sp++);

	}

	pr_emerg("\n");

	pr_emerg("\nKERNEL STACK:");

	tp = ((unsigned char *) fp) - 0x40;

	for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {

		if ((i % 0x10) == 0)

			pr_emerg("\n%08x: ", (int) (tp + i));

		pr_emerg("%08x ", (int) *sp++);

	}

	pr_emerg("\n");

	pr_emerg("\n");

	pr_emerg("\nUSER STACK:");

	tp = (unsigned char *) (fp->sp - 0x10);

	for (sp = (unsigned long *) tp, i = 0; (i < 0x80); i += 4) {

		if ((i % 0x10) == 0)

			pr_emerg("\n%08x: ", (int) (tp + i));

		pr_emerg("%08x ", (int) *sp++);

	}

	pr_emerg("\n\n");

}

unsigned long get_wchan(struct task_struct *p)

{

	unsigned long fp, pc;

	unsigned long stack_page;

	int count = 0;

	if (!p || p == current || p->state == TASK_RUNNING)

		return 0;

	stack_page = (unsigned long)p;

	fp = ((struct switch_stack *)p->thread.ksp)->fp;	/* ;dgt2 */

	do {

		if (fp < stack_page+sizeof(struct task_struct) ||

			fp >= 8184+stack_page)	/* ;dgt2;tmp */

			return 0;

		pc = ((unsigned long *)fp)[1];

		if (!in_sched_functions(pc))

			return pc;

		fp = *(unsigned long *) fp;

	} while (count++ < 16);		/* ;dgt2;tmp */

	return 0;

}

/*

 * Do necessary setup to start up a newly executed thread.

 * Will startup in user mode (status_extension = 0).

 */

void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp)

{

	memset((void *) regs, 0, sizeof(struct pt_regs));

	regs->estatus = ESTATUS_EPIE | ESTATUS_EU;

	regs->ea = pc;

	regs->sp = sp;

}

#include <linux/elfcore.h>

/* Fill in the FPU structure for a core dump. */

int dump_fpu(struct pt_regs *regs, elf_fpregset_t *r)

{

	return 0; /* Nios2 has no FPU and thus no FPU registers */

}