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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/cris/arch-v10/kernel/process.c
downloadconfigs-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/cris/arch-v10/kernel/process.c')
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diff --git a/arch/cris/arch-v10/kernel/process.c b/arch/cris/arch-v10/kernel/process.c
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+++ b/arch/cris/arch-v10/kernel/process.c
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+/* $Id: process.c,v 1.9 2004/10/19 13:07:37 starvik Exp $
+ *
+ * linux/arch/cris/kernel/process.c
+ *
+ * Copyright (C) 1995 Linus Torvalds
+ * Copyright (C) 2000-2002 Axis Communications AB
+ *
+ * Authors: Bjorn Wesen (bjornw@axis.com)
+ * Mikael Starvik (starvik@axis.com)
+ *
+ * This file handles the architecture-dependent parts of process handling..
+ */
+
+#include <linux/config.h>
+#include <linux/sched.h>
+#include <linux/err.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <asm/arch/svinto.h>
+#include <linux/init.h>
+
+#ifdef CONFIG_ETRAX_GPIO
+void etrax_gpio_wake_up_check(void); /* drivers/gpio.c */
+#endif
+
+/*
+ * We use this if we don't have any better
+ * idle routine..
+ */
+void default_idle(void)
+{
+#ifdef CONFIG_ETRAX_GPIO
+ etrax_gpio_wake_up_check();
+#endif
+}
+
+/*
+ * Free current thread data structures etc..
+ */
+
+void exit_thread(void)
+{
+ /* Nothing needs to be done. */
+}
+
+/* if the watchdog is enabled, we can simply disable interrupts and go
+ * into an eternal loop, and the watchdog will reset the CPU after 0.1s
+ * if on the other hand the watchdog wasn't enabled, we just enable it and wait
+ */
+
+void hard_reset_now (void)
+{
+ /*
+ * Don't declare this variable elsewhere. We don't want any other
+ * code to know about it than the watchdog handler in entry.S and
+ * this code, implementing hard reset through the watchdog.
+ */
+#if defined(CONFIG_ETRAX_WATCHDOG) && !defined(CONFIG_SVINTO_SIM)
+ extern int cause_of_death;
+#endif
+
+ printk("*** HARD RESET ***\n");
+ local_irq_disable();
+
+#if defined(CONFIG_ETRAX_WATCHDOG) && !defined(CONFIG_SVINTO_SIM)
+ cause_of_death = 0xbedead;
+#else
+ /* Since we dont plan to keep on reseting the watchdog,
+ the key can be arbitrary hence three */
+ *R_WATCHDOG = IO_FIELD(R_WATCHDOG, key, 3) |
+ IO_STATE(R_WATCHDOG, enable, start);
+#endif
+
+ while(1) /* waiting for RETRIBUTION! */ ;
+}
+
+/*
+ * Return saved PC of a blocked thread.
+ */
+unsigned long thread_saved_pc(struct task_struct *t)
+{
+ return (unsigned long)user_regs(t->thread_info)->irp;
+}
+
+static void kernel_thread_helper(void* dummy, int (*fn)(void *), void * arg)
+{
+ fn(arg);
+ do_exit(-1); /* Should never be called, return bad exit value */
+}
+
+/*
+ * Create a kernel thread
+ */
+int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
+{
+ struct pt_regs regs;
+
+ memset(&regs, 0, sizeof(regs));
+
+ /* Don't use r10 since that is set to 0 in copy_thread */
+ regs.r11 = (unsigned long)fn;
+ regs.r12 = (unsigned long)arg;
+ regs.irp = (unsigned long)kernel_thread_helper;
+
+ /* Ok, create the new process.. */
+ return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
+}
+
+/* setup the child's kernel stack with a pt_regs and switch_stack on it.
+ * it will be un-nested during _resume and _ret_from_sys_call when the
+ * new thread is scheduled.
+ *
+ * also setup the thread switching structure which is used to keep
+ * thread-specific data during _resumes.
+ *
+ */
+asmlinkage void ret_from_fork(void);
+
+int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
+ unsigned long unused,
+ struct task_struct *p, struct pt_regs *regs)
+{
+ struct pt_regs * childregs;
+ struct switch_stack *swstack;
+
+ /* put the pt_regs structure at the end of the new kernel stack page and fix it up
+ * remember that the task_struct doubles as the kernel stack for the task
+ */
+
+ childregs = user_regs(p->thread_info);
+
+ *childregs = *regs; /* struct copy of pt_regs */
+
+ p->set_child_tid = p->clear_child_tid = NULL;
+
+ childregs->r10 = 0; /* child returns 0 after a fork/clone */
+
+ /* put the switch stack right below the pt_regs */
+
+ swstack = ((struct switch_stack *)childregs) - 1;
+
+ swstack->r9 = 0; /* parameter to ret_from_sys_call, 0 == dont restart the syscall */
+
+ /* we want to return into ret_from_sys_call after the _resume */
+
+ swstack->return_ip = (unsigned long) ret_from_fork; /* Will call ret_from_sys_call */
+
+ /* fix the user-mode stackpointer */
+
+ p->thread.usp = usp;
+
+ /* and the kernel-mode one */
+
+ p->thread.ksp = (unsigned long) swstack;
+
+#ifdef DEBUG
+ printk("copy_thread: new regs at 0x%p, as shown below:\n", childregs);
+ show_registers(childregs);
+#endif
+
+ return 0;
+}
+
+/*
+ * Be aware of the "magic" 7th argument in the four system-calls below.
+ * They need the latest stackframe, which is put as the 7th argument by
+ * entry.S. The previous arguments are dummies or actually used, but need
+ * to be defined to reach the 7th argument.
+ *
+ * N.B.: Another method to get the stackframe is to use current_regs(). But
+ * it returns the latest stack-frame stacked when going from _user mode_ and
+ * some of these (at least sys_clone) are called from kernel-mode sometimes
+ * (for example during kernel_thread, above) and thus cannot use it. Thus,
+ * to be sure not to get any surprises, we use the method for the other calls
+ * as well.
+ */
+
+asmlinkage int sys_fork(long r10, long r11, long r12, long r13, long mof, long srp,
+ struct pt_regs *regs)
+{
+ return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
+}
+
+/* if newusp is 0, we just grab the old usp */
+/* FIXME: Is parent_tid/child_tid really third/fourth argument? Update lib? */
+asmlinkage int sys_clone(unsigned long newusp, unsigned long flags,
+ int* parent_tid, int* child_tid, long mof, long srp,
+ struct pt_regs *regs)
+{
+ if (!newusp)
+ newusp = rdusp();
+ return do_fork(flags, newusp, regs, 0, parent_tid, child_tid);
+}
+
+/* vfork is a system call in i386 because of register-pressure - maybe
+ * we can remove it and handle it in libc but we put it here until then.
+ */
+
+asmlinkage int sys_vfork(long r10, long r11, long r12, long r13, long mof, long srp,
+ struct pt_regs *regs)
+{
+ return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL);
+}
+
+/*
+ * sys_execve() executes a new program.
+ */
+asmlinkage int sys_execve(const char *fname, char **argv, char **envp,
+ long r13, long mof, long srp,
+ struct pt_regs *regs)
+{
+ int error;
+ char *filename;
+
+ filename = getname(fname);
+ 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)
+{
+#if 0
+ /* YURGH. TODO. */
+
+ unsigned long ebp, esp, eip;
+ unsigned long stack_page;
+ int count = 0;
+ if (!p || p == current || p->state == TASK_RUNNING)
+ return 0;
+ stack_page = (unsigned long)p;
+ esp = p->thread.esp;
+ if (!stack_page || esp < stack_page || esp > 8188+stack_page)
+ return 0;
+ /* include/asm-i386/system.h:switch_to() pushes ebp last. */
+ ebp = *(unsigned long *) esp;
+ do {
+ if (ebp < stack_page || ebp > 8184+stack_page)
+ return 0;
+ eip = *(unsigned long *) (ebp+4);
+ if (!in_sched_functions(eip))
+ return eip;
+ ebp = *(unsigned long *) ebp;
+ } while (count++ < 16);
+#endif
+ return 0;
+}
+#undef last_sched
+#undef first_sched
+
+void show_regs(struct pt_regs * regs)
+{
+ unsigned long usp = rdusp();
+ printk("IRP: %08lx SRP: %08lx DCCR: %08lx USP: %08lx MOF: %08lx\n",
+ regs->irp, regs->srp, regs->dccr, usp, regs->mof );
+ printk(" r0: %08lx r1: %08lx r2: %08lx r3: %08lx\n",
+ regs->r0, regs->r1, regs->r2, regs->r3);
+ printk(" r4: %08lx r5: %08lx r6: %08lx r7: %08lx\n",
+ regs->r4, regs->r5, regs->r6, regs->r7);
+ printk(" r8: %08lx r9: %08lx r10: %08lx r11: %08lx\n",
+ regs->r8, regs->r9, regs->r10, regs->r11);
+ printk("r12: %08lx r13: %08lx oR10: %08lx\n",
+ regs->r12, regs->r13, regs->orig_r10);
+}
+