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linux/arch/parisc/kernel/process.c

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/*
* PARISC Architecture-dependent parts of process handling
* based on the work for i386
*
* Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org>
* Copyright (C) 2000 Martin K Petersen <mkp at mkp.net>
* Copyright (C) 2000 John Marvin <jsm at parisc-linux.org>
* Copyright (C) 2000 David Huggins-Daines <dhd with pobox.org>
* Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org>
* Copyright (C) 2000 Philipp Rumpf <prumpf with tux.org>
* Copyright (C) 2000 David Kennedy <dkennedy with linuxcare.com>
* Copyright (C) 2000 Richard Hirst <rhirst with parisc-linux.org>
* Copyright (C) 2000 Grant Grundler <grundler with parisc-linux.org>
* Copyright (C) 2001 Alan Modra <amodra at parisc-linux.org>
* Copyright (C) 2001-2002 Ryan Bradetich <rbrad at parisc-linux.org>
* Copyright (C) 2001-2002 Helge Deller <deller at parisc-linux.org>
* Copyright (C) 2002 Randolph Chung <tausq with parisc-linux.org>
*
*
* 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 program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <stdarg.h>
#include <linux/elf.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/personality.h>
#include <linux/ptrace.h>
#include <linux/sched.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/kallsyms.h>
#include <asm/io.h>
#include <asm/asm-offsets.h>
#include <asm/pdc.h>
#include <asm/pdc_chassis.h>
#include <asm/pgalloc.h>
#include <asm/uaccess.h>
#include <asm/unwind.h>
/*
* The idle thread. There's no useful work to be
* done, so just try to conserve power and have a
* low exit latency (ie sit in a loop waiting for
* somebody to say that they'd like to reschedule)
*/
void cpu_idle(void)
{
[PATCH] sched: resched and cpu_idle rework Make some changes to the NEED_RESCHED and POLLING_NRFLAG to reduce confusion, and make their semantics rigid. Improves efficiency of resched_task and some cpu_idle routines. * In resched_task: - TIF_NEED_RESCHED is only cleared with the task's runqueue lock held, and as we hold it during resched_task, then there is no need for an atomic test and set there. The only other time this should be set is when the task's quantum expires, in the timer interrupt - this is protected against because the rq lock is irq-safe. - If TIF_NEED_RESCHED is set, then we don't need to do anything. It won't get unset until the task get's schedule()d off. - If we are running on the same CPU as the task we resched, then set TIF_NEED_RESCHED and no further action is required. - If we are running on another CPU, and TIF_POLLING_NRFLAG is *not* set after TIF_NEED_RESCHED has been set, then we need to send an IPI. Using these rules, we are able to remove the test and set operation in resched_task, and make clear the previously vague semantics of POLLING_NRFLAG. * In idle routines: - Enter cpu_idle with preempt disabled. When the need_resched() condition becomes true, explicitly call schedule(). This makes things a bit clearer (IMO), but haven't updated all architectures yet. - Many do a test and clear of TIF_NEED_RESCHED for some reason. According to the resched_task rules, this isn't needed (and actually breaks the assumption that TIF_NEED_RESCHED is only cleared with the runqueue lock held). So remove that. Generally one less locked memory op when switching to the idle thread. - Many idle routines clear TIF_POLLING_NRFLAG, and only set it in the inner most polling idle loops. The above resched_task semantics allow it to be set until before the last time need_resched() is checked before going into a halt requiring interrupt wakeup. Many idle routines simply never enter such a halt, and so POLLING_NRFLAG can be always left set, completely eliminating resched IPIs when rescheduling the idle task. POLLING_NRFLAG width can be increased, to reduce the chance of resched IPIs. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Con Kolivas <kernel@kolivas.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-08 22:39:04 -07:00
set_thread_flag(TIF_POLLING_NRFLAG);
/* endless idle loop with no priority at all */
while (1) {
while (!need_resched())
barrier();
preempt_enable_no_resched();
schedule();
preempt_disable();
check_pgt_cache();
}
}
#define COMMAND_GLOBAL F_EXTEND(0xfffe0030)
#define CMD_RESET 5 /* reset any module */
/*
** The Wright Brothers and Gecko systems have a H/W problem
** (Lasi...'nuf said) may cause a broadcast reset to lockup
** the system. An HVERSION dependent PDC call was developed
** to perform a "safe", platform specific broadcast reset instead
** of kludging up all the code.
**
** Older machines which do not implement PDC_BROADCAST_RESET will
** return (with an error) and the regular broadcast reset can be
** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET
** the PDC call will not return (the system will be reset).
*/
void machine_restart(char *cmd)
{
#ifdef FASTBOOT_SELFTEST_SUPPORT
/*
** If user has modified the Firmware Selftest Bitmap,
** run the tests specified in the bitmap after the
** system is rebooted w/PDC_DO_RESET.
**
** ftc_bitmap = 0x1AUL "Skip destructive memory tests"
**
** Using "directed resets" at each processor with the MEM_TOC
** vector cleared will also avoid running destructive
** memory self tests. (Not implemented yet)
*/
if (ftc_bitmap) {
pdc_do_firm_test_reset(ftc_bitmap);
}
#endif
/* set up a new led state on systems shipped with a LED State panel */
pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
/* "Normal" system reset */
pdc_do_reset();
/* Nope...box should reset with just CMD_RESET now */
gsc_writel(CMD_RESET, COMMAND_GLOBAL);
/* Wait for RESET to lay us to rest. */
while (1) ;
}
void machine_halt(void)
{
/*
** The LED/ChassisCodes are updated by the led_halt()
** function, called by the reboot notifier chain.
*/
}
void (*chassis_power_off)(void);
/*
* This routine is called from sys_reboot to actually turn off the
* machine
*/
void machine_power_off(void)
{
/* If there is a registered power off handler, call it. */
if (chassis_power_off)
chassis_power_off();
/* Put the soft power button back under hardware control.
* If the user had already pressed the power button, the
* following call will immediately power off. */
pdc_soft_power_button(0);
pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
/* It seems we have no way to power the system off via
* software. The user has to press the button himself. */
printk(KERN_EMERG "System shut down completed.\n"
KERN_EMERG "Please power this system off now.");
}
void (*pm_power_off)(void) = machine_power_off;
EXPORT_SYMBOL(pm_power_off);
/*
* Create a kernel thread
*/
extern pid_t __kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
{
/*
* FIXME: Once we are sure we don't need any debug here,
* kernel_thread can become a #define.
*/
return __kernel_thread(fn, arg, flags);
}
EXPORT_SYMBOL(kernel_thread);
/*
* Free current thread data structures etc..
*/
void exit_thread(void)
{
}
void flush_thread(void)
{
/* Only needs to handle fpu stuff or perf monitors.
** REVISIT: several arches implement a "lazy fpu state".
*/
set_fs(USER_DS);
}
void release_thread(struct task_struct *dead_task)
{
}
/*
* Fill in the FPU structure for a core dump.
*/
int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r)
{
if (regs == NULL)
return 0;
memcpy(r, regs->fr, sizeof *r);
return 1;
}
int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r)
{
memcpy(r, tsk->thread.regs.fr, sizeof(*r));
return 1;
}
/* Note that "fork()" is implemented in terms of clone, with
parameters (SIGCHLD, regs->gr[30], regs). */
int
sys_clone(unsigned long clone_flags, unsigned long usp,
struct pt_regs *regs)
{
/* Arugments from userspace are:
r26 = Clone flags.
r25 = Child stack.
r24 = parent_tidptr.
r23 = Is the TLS storage descriptor
r22 = child_tidptr
However, these last 3 args are only examined
if the proper flags are set. */
int __user *child_tidptr;
int __user *parent_tidptr;
/* usp must be word aligned. This also prevents users from
* passing in the value 1 (which is the signal for a special
* return for a kernel thread) */
usp = ALIGN(usp, 4);
/* A zero value for usp means use the current stack */
if (usp == 0)
usp = regs->gr[30];
if (clone_flags & CLONE_PARENT_SETTID)
parent_tidptr = (int __user *)regs->gr[24];
else
parent_tidptr = NULL;
if (clone_flags & (CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID))
child_tidptr = (int __user *)regs->gr[22];
else
child_tidptr = NULL;
return do_fork(clone_flags, usp, regs, 0, parent_tidptr, child_tidptr);
}
int
sys_vfork(struct pt_regs *regs)
{
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gr[30], regs, 0, NULL, NULL);
}
int
copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
unsigned long unused, /* in ia64 this is "user_stack_size" */
struct task_struct * p, struct pt_regs * pregs)
{
struct pt_regs * cregs = &(p->thread.regs);
void *stack = task_stack_page(p);
/* We have to use void * instead of a function pointer, because
* function pointers aren't a pointer to the function on 64-bit.
* Make them const so the compiler knows they live in .text */
extern void * const ret_from_kernel_thread;
extern void * const child_return;
#ifdef CONFIG_HPUX
extern void * const hpux_child_return;
#endif
*cregs = *pregs;
/* Set the return value for the child. Note that this is not
actually restored by the syscall exit path, but we put it
here for consistency in case of signals. */
cregs->gr[28] = 0; /* child */
/*
* We need to differentiate between a user fork and a
* kernel fork. We can't use user_mode, because the
* the syscall path doesn't save iaoq. Right now
* We rely on the fact that kernel_thread passes
* in zero for usp.
*/
if (usp == 1) {
/* kernel thread */
cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN;
/* Must exit via ret_from_kernel_thread in order
* to call schedule_tail()
*/
cregs->kpc = (unsigned long) &ret_from_kernel_thread;
/*
* Copy function and argument to be called from
* ret_from_kernel_thread.
*/
#ifdef __LP64__
cregs->gr[27] = pregs->gr[27];
#endif
cregs->gr[26] = pregs->gr[26];
cregs->gr[25] = pregs->gr[25];
} else {
/* user thread */
/*
* Note that the fork wrappers are responsible
* for setting gr[21].
*/
/* Use same stack depth as parent */
cregs->ksp = (unsigned long)stack
+ (pregs->gr[21] & (THREAD_SIZE - 1));
cregs->gr[30] = usp;
if (p->personality == PER_HPUX) {
#ifdef CONFIG_HPUX
cregs->kpc = (unsigned long) &hpux_child_return;
#else
BUG();
#endif
} else {
cregs->kpc = (unsigned long) &child_return;
}
/* Setup thread TLS area from the 4th parameter in clone */
if (clone_flags & CLONE_SETTLS)
cregs->cr27 = pregs->gr[23];
}
return 0;
}
unsigned long thread_saved_pc(struct task_struct *t)
{
return t->thread.regs.kpc;
}
/*
* sys_execve() executes a new program.
*/
asmlinkage int sys_execve(struct pt_regs *regs)
{
int error;
char *filename;
filename = getname((const char __user *) regs->gr[26]);
error = PTR_ERR(filename);
if (IS_ERR(filename))
goto out;
error = do_execve(filename, (char __user **) regs->gr[25],
(char __user **) regs->gr[24], regs);
if (error == 0) {
task_lock(current);
current->ptrace &= ~PT_DTRACE;
task_unlock(current);
}
putname(filename);
out:
return error;
}
[PATCH] rename the provided execve functions to kernel_execve Some architectures provide an execve function that does not set errno, but instead returns the result code directly. Rename these to kernel_execve to get the right semantics there. Moreover, there is no reasone for any of these architectures to still provide __KERNEL_SYSCALLS__ or _syscallN macros, so remove these right away. [akpm@osdl.org: build fix] [bunk@stusta.de: build fix] Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Andi Kleen <ak@muc.de> Acked-by: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Ian Molton <spyro@f2s.com> Cc: Mikael Starvik <starvik@axis.com> Cc: David Howells <dhowells@redhat.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Hirokazu Takata <takata.hirokazu@renesas.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp> Cc: Richard Curnow <rc@rc0.org.uk> Cc: William Lee Irwin III <wli@holomorphy.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp> Cc: Chris Zankel <chris@zankel.net> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Adrian Bunk <bunk@stusta.de> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 02:18:31 -07:00
extern int __execve(const char *filename, char *const argv[],
char *const envp[], struct task_struct *task);
int kernel_execve(const char *filename, char *const argv[], char *const envp[])
{
return __execve(filename, argv, envp, current);
}
unsigned long
get_wchan(struct task_struct *p)
{
struct unwind_frame_info info;
unsigned long ip;
int count = 0;
/*
* These bracket the sleeping functions..
*/
unwind_frame_init_from_blocked_task(&info, p);
do {
if (unwind_once(&info) < 0)
return 0;
ip = info.ip;
if (!in_sched_functions(ip))
return ip;
} while (count++ < 16);
return 0;
}