Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753881Ab1FSLrk (ORCPT ); Sun, 19 Jun 2011 07:47:40 -0400 Received: from mail.southpole.se ([193.12.106.18]:37749 "EHLO mail.southpole.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753604Ab1FSLpW (ORCPT ); Sun, 19 Jun 2011 07:45:22 -0400 From: Jonas Bonn To: linux-kernel@vger.kernel.org Cc: Jonas Bonn Subject: [PATCH 12/19] OpenRISC: Scheduling/Process management Date: Sun, 19 Jun 2011 13:43:38 +0200 Message-Id: <1308483825-6023-13-git-send-email-jonas@southpole.se> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1308483825-6023-1-git-send-email-jonas@southpole.se> References: <1308483825-6023-1-git-send-email-jonas@southpole.se> X-Assp-Client-SSL: yes Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 15428 Lines: 547 Signed-off-by: Jonas Bonn --- arch/openrisc/include/asm/thread_info.h | 167 +++++++++++++++ arch/openrisc/kernel/process.c | 351 +++++++++++++++++++++++++++++++ 2 files changed, 518 insertions(+), 0 deletions(-) create mode 100644 arch/openrisc/include/asm/thread_info.h create mode 100644 arch/openrisc/kernel/process.c diff --git a/arch/openrisc/include/asm/thread_info.h b/arch/openrisc/include/asm/thread_info.h new file mode 100644 index 0000000..e9cb19b --- /dev/null +++ b/arch/openrisc/include/asm/thread_info.h @@ -0,0 +1,167 @@ +/* + * OpenRISC Linux + * + * Linux architectural port borrowing liberally from similar works of + * others. All original copyrights apply as per the original source + * declaration. + * + * OpenRISC implementation: + * Copyright (C) 2003 Matjaz Breskvar + * Copyright (C) 2010-2011 Jonas Bonn + * et al. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#ifndef _ASM_THREAD_INFO_H +#define _ASM_THREAD_INFO_H + +#ifdef __KERNEL__ + +#ifndef __ASSEMBLY__ +#include +#include +#endif + + +/* THREAD_SIZE is the size of the task_struct/kernel_stack combo. + * normally, the stack is found by doing something like p + THREAD_SIZE + * in or32, a page is 8192 bytes, which seems like a sane size + */ + +#define THREAD_SIZE PAGE_SIZE +#define THREAD_SIZE_ORDER 1 + +/* + * 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 + */ +#ifndef __ASSEMBLY__ + +typedef unsigned long mm_segment_t; + +struct debug_entry { + unsigned long address; /* Address of breakpoint */ + unsigned long insn; /* Instruction replaced */ + unsigned long set; /* Is BP active? */ + unsigned long branch; /* BP is after a branch */ + unsigned long branch_target; /* Branch address */ + unsigned long branch_insn_address; /* PC of l.b/l.j */ +}; + +struct debug_info { + struct debug_entry bp; +}; + +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 */ + __s32 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; + __u8 supervisor_stack[0]; + + /* saved context data */ + unsigned long ksp; + + struct debug_info debug; +}; +#endif + +//#define PREEMPT_ACTIVE 0x4000000 + +/* + * macros/functions for gaining access to the thread information structure + * + * preempt_count needs to be 1 initially, until the scheduler is functional. + */ +#ifndef __ASSEMBLY__ +#define INIT_THREAD_INFO(tsk) \ +{ \ + .task = &tsk, \ + .exec_domain = &default_exec_domain, \ + .flags = 0, \ + .cpu = 0, \ + .preempt_count = 1, \ + .addr_limit = KERNEL_DS, \ + .restart_block = { \ + .fn = do_no_restart_syscall, \ + }, \ + .ksp = 0, \ +} + +#define init_thread_info (init_thread_union.thread_info) + +#if 0 +/* how to get the thread information struct from C */ +static inline struct thread_info *current_thread_info(void) +{ + struct thread_info *ti; + __asm__("/* current_thread_info */" + "l.srli %0,r1,%1;" + "l.slli %0,%0,%1" : "=r" (ti) : "K" (PAGE_SHIFT)); + return ti; +} +#endif +#if 0 +/* how to get the thread information struct from C */ +static inline struct thread_info *current_thread_info(void) +{ + struct thread_info *ti; + __asm__("l.ori %0,r10,%1" : "=r" (ti) : "K" (0)); + return ti; +} +#endif + +/* how to get the thread information struct from C */ +register struct thread_info *current_thread_info_reg asm("r10"); +#define current_thread_info() (current_thread_info_reg) + +#define get_thread_info(ti) get_task_struct((ti)->task) +#define put_thread_info(ti) put_task_struct((ti)->task) + +#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_SINGLESTEP 4 /* restore singlestep on return to user mode */ +#define TIF_SYSCALL_TRACEPOINT 8 /* for ftrace syscall instrumentation */ +#define TIF_RESTORE_SIGMASK 9 +#define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */ +#define TIF_MEMDIE 17 + +#define _TIF_SYSCALL_TRACE (1< + * Copyright (C) 2010-2011 Jonas Bonn + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * This file handles the architecture-dependent parts of process handling... + */ + +#define __KERNEL_SYSCALLS__ +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include + + +#include + +/* + * Pointer to Current thread info structure. + * + * Used at user space -> kernel transitions. + */ +struct thread_info *current_thread_info_set[NR_CPUS] = {&init_thread_info, }; + +#if 0 + +/* + * The hlt_counter, disable_hlt and enable_hlt is just here as a hook if + * there would ever be a halt sequence (for power save when idle) with + * some largish delay when halting or resuming *and* a driver that can't + * afford that delay. The hlt_counter would then be checked before + * executing the halt sequence, and the driver marks the unhaltable + * region by enable_hlt/disable_hlt. + */ + +static int hlt_counter=0; + +void disable_hlt(void) +{ + hlt_counter++; +} + +EXPORT_SYMBOL(disable_hlt); + +void enable_hlt(void) +{ + hlt_counter--; +} + +EXPORT_SYMBOL(enable_hlt); +#endif + + +void machine_restart(void) +{ + printk("*** MACHINE RESTART ***\n"); + __asm__("l.nop 1"); +} + +EXPORT_SYMBOL(machine_restart); + +/* + * Similar to machine_power_off, but don't shut off power. Add code + * here to freeze the system for e.g. post-mortem debug purpose when + * possible. This halt has nothing to do with the idle halt. + */ + +void machine_halt(void) +{ + printk("*** MACHINE HALT ***\n"); + __asm__("l.nop 1"); +} + +EXPORT_SYMBOL(machine_halt); + +/* If or when software power-off is implemented, add code here. */ + +void machine_power_off(void) +{ + printk("*** MACHINE POWER OFF ***\n"); + __asm__("l.nop 1"); +} + +EXPORT_SYMBOL(machine_power_off); + +void (*pm_power_off)(void) = machine_power_off; +EXPORT_SYMBOL(pm_power_off); + +/* + * When a process does an "exec", machine state like FPU and debug + * registers need to be reset. This is a hook function for that. + * Currently we don't have any such state to reset, so this is empty. + */ + +void flush_thread(void) +{ +} + +void show_regs(struct pt_regs *regs) +{ + extern void show_registers(struct pt_regs *regs); + + /* __PHX__ cleanup this mess */ + show_registers(regs); +} + +unsigned long thread_saved_pc(struct task_struct *t) +{ + return (unsigned long)user_regs(t->stack)->pc; +} + +void release_thread(struct task_struct *dead_task) +{ +} + +/* + * Copy the thread-specific (arch specific) info from the current + * process to the new one p + */ + +extern asmlinkage void ret_from_fork(void); + +int +copy_thread(unsigned long clone_flags, unsigned long usp, + unsigned long unused, + struct task_struct *p, struct pt_regs *regs) +{ + struct pt_regs* childregs; + struct pt_regs* kregs; + unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE; + struct thread_info *ti; + unsigned long top_of_kernel_stack; + + top_of_kernel_stack = sp; + + p->set_child_tid = p->clear_child_tid = NULL; + + /* Copy registers */ + /* redzone */ + sp -= STACK_FRAME_OVERHEAD; + sp -= sizeof(struct pt_regs); + childregs = (struct pt_regs *) sp; + + /* Copy parent registers */ + *childregs = *regs; + + if ((childregs->sr & SPR_SR_SM) == 1) { + /* for kernel thread, set `current_thread_info' + * and stackptr in new task + */ + childregs->sp = (unsigned long)task_stack_page(p) + THREAD_SIZE; + childregs->gpr[10] = (unsigned long)task_thread_info(p); + } else { + childregs->sp = usp; + } + + childregs->gpr[11] = 0; /* Result from fork() */ + + /* + * The way this works is that at some point in the future + * some task will call _switch to switch to the new task. + * That will pop off the stack frame created below and start + * the new task running at ret_from_fork. The new task will + * do some house keeping and then return from the fork or clone + * system call, using the stack frame created above. + */ + /* redzone */ + sp -= STACK_FRAME_OVERHEAD; + sp -= sizeof(struct pt_regs); + kregs = (struct pt_regs *) sp; + + ti = task_thread_info(p); + ti->ksp = sp; + +// kregs->sr = regs->sr | SPR_SR_SM; + /* kregs->sp must store the location of the 'pre-switch' kernel stack + * pointer... for a newly forked process, this is simply the top of + * the kernel stack. + */ + kregs->sp = top_of_kernel_stack; +// kregs->sp = sp + sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD; + kregs->gpr[3] = (unsigned long)current; /* arg to schedule_tail */ + kregs->gpr[10] = (unsigned long)task_thread_info(p); +// kregs->pc = (unsigned long)ret_from_fork; + kregs->gpr[9] = (unsigned long)ret_from_fork; + + return 0; +} + +/* + * Set up a thread for executing a new program + */ +void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp) +{ + unsigned long sr = regs->sr & ~SPR_SR_SM; + + set_fs(USER_DS); + memset(regs->gpr, 0, sizeof(regs->gpr)); + + regs->pc = pc; + regs->sr = sr; + regs->sp = sp; + +/* printk("start thread, ksp = %lx\n", current_thread_info()->ksp);*/ +} + +/* Fill in the fpu structure for a core dump. */ +int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu) +{ + /* TODO */ + return 0; +} + +extern struct thread_info* _switch(struct thread_info *old_ti, + struct thread_info *new_ti); + +struct task_struct* __switch_to(struct task_struct* old, + struct task_struct* new) +{ + struct task_struct* last; + struct thread_info *new_ti, *old_ti; + unsigned long flags; + + local_irq_save(flags); + + /* current_set is an array of saved current pointers + * (one for each cpu). we need them at user->kernel transition, + * while we save them at kernel->user transition + */ + new_ti = new->stack; + old_ti = old->stack; + + current_thread_info_set[smp_processor_id()] = new_ti; + last = (_switch(old_ti, new_ti))->task; + + local_irq_restore(flags); + + return last; +} + +/* + * fill in the user structure for a core dump.. + */ +void dump_thread(struct pt_regs *regs, struct user *dump) +{ + /* TODO */ +} + +extern void _kernel_thread_helper(void); + +void __noreturn kernel_thread_helper(int (*fn)(void *), void *arg) +{ + do_exit(fn(arg)); +} + +/* + * Create a kernel thread. + */ +int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) +{ + struct pt_regs regs; + + memset(®s, 0, sizeof(regs)); + + regs.gpr[20] = (unsigned long)fn; + regs.gpr[22] = (unsigned long)arg; + regs.sr = mfspr(SPR_SR); + regs.pc = (unsigned long)_kernel_thread_helper; + + return do_fork(flags | CLONE_VM | CLONE_UNTRACED, + 0, ®s, 0, NULL, NULL); +} + +/* + * sys_execve() executes a new program. + */ +asmlinkage long _sys_execve(const char __user *name, + const char __user *const __user *argv, + const char __user *const __user *envp, + struct pt_regs *regs) +{ + int error; + char * filename; + + filename = getname(name); + error = PTR_ERR(filename); + + if (IS_ERR(filename)) + goto out; + + error = do_execve(filename, argv, envp, regs); + putname(filename); + +out: + return error; +} + +unsigned long get_wchan(struct task_struct *p) +{ + /* TODO */ + + return 0; +} + +int kernel_execve(const char *filename, char *const argv[], char *const +envp[]) +{ + register long __res asm("r11") = __NR_execve; + register long __a asm("r3") = (long)(filename); + register long __b asm("r4") = (long)(argv); + register long __c asm("r5") = (long)(envp); + __asm__ volatile ("l.sys 1" + : "=r" (__res), "=r" (__a), "=r" (__b), "=r" (__c) + : "0" (__res), "1" (__a), "2" (__b), "3" (__c) + : "r6", "r7", "r8", "r12", "r13", "r15", + "r17", "r19", "r21", "r23", "r25", "r27", + "r29", "r31"); + __asm__ volatile("l.nop"); + return __res; +} -- 1.7.4.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/