diff options
Diffstat (limited to 'arch/cris/arch-v32/kernel/process.c')
| -rw-r--r-- | arch/cris/arch-v32/kernel/process.c | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/arch/cris/arch-v32/kernel/process.c b/arch/cris/arch-v32/kernel/process.c new file mode 100644 index 0000000..882be42 --- /dev/null +++ b/arch/cris/arch-v32/kernel/process.c @@ -0,0 +1,270 @@ +/* + * Copyright (C) 2000-2003 Axis Communications AB + * + * Authors: Bjorn Wesen (bjornw@axis.com) + * Mikael Starvik (starvik@axis.com) + * Tobias Anderberg (tobiasa@axis.com), CRISv32 port. + * + * 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/hwregs/reg_rdwr.h> +#include <asm/arch/hwregs/reg_map.h> +#include <asm/arch/hwregs/timer_defs.h> +#include <asm/arch/hwregs/intr_vect_defs.h> + +extern void stop_watchdog(void); + +#ifdef CONFIG_ETRAX_GPIO +extern void etrax_gpio_wake_up_check(void); /* Defined in drivers/gpio.c. */ +#endif + +extern int cris_hlt_counter; + +/* We use this if we don't have any better idle routine. */ +void default_idle(void) +{ + local_irq_disable(); + if (!need_resched() && !cris_hlt_counter) { + /* Halt until exception. */ + __asm__ volatile("ei \n\t" + "halt "); + } + local_irq_enable(); +} + +/* + * Free current thread data structures etc.. + */ + +extern void deconfigure_bp(long pid); +void exit_thread(void) +{ + deconfigure_bp(current->pid); +} + +/* + * If the watchdog is enabled, disable interrupts and enter an infinite loop. + * The watchdog will reset the CPU after 0.1s. If the watchdog isn't enabled + * then enable it and wait. + */ +extern void arch_enable_nmi(void); + +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) + extern int cause_of_death; +#endif + + printk("*** HARD RESET ***\n"); + local_irq_disable(); + +#if defined(CONFIG_ETRAX_WATCHDOG) + cause_of_death = 0xbedead; +#else +{ + reg_timer_rw_wd_ctrl wd_ctrl = {0}; + + stop_watchdog(); + + wd_ctrl.key = 16; /* Arbitrary key. */ + wd_ctrl.cnt = 1; /* Minimum time. */ + wd_ctrl.cmd = regk_timer_start; + + arch_enable_nmi(); + REG_WR(timer, regi_timer, rw_wd_ctrl, wd_ctrl); +} +#endif + + while (1) + ; /* Wait for reset. */ +} + +/* + * Return saved PC of a blocked thread. + */ +unsigned long thread_saved_pc(struct task_struct *t) +{ + return (unsigned long)user_regs(t->thread_info)->erp; +} + +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(®s, 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.erp = (unsigned long) kernel_thread_helper; + regs.ccs = 1 << (I_CCS_BITNR + CCS_SHIFT); + + /* Create the new process. */ + return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); +} + +/* + * Setup the child's kernel stack with a pt_regs and call switch_stack() on it. + * It will be unnested 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. + */ + +extern 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. Note: 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. */ + + /* Set a new TLS ? + * The TLS is in $mof beacuse it is the 5th argument to sys_clone. + */ + if (p->mm && (clone_flags & CLONE_SETTLS)) { + p->thread_info->tls = regs->mof; + } + + /* Put the switch stack right below the pt_regs. */ + swstack = ((struct switch_stack *) childregs) - 1; + + /* Paramater to ret_from_sys_call. 0 is don't restart the syscall. */ + swstack->r9 = 0; + + /* + * We want to return into ret_from_sys_call after the _resume. + * ret_from_fork will call ret_from_sys_call. + */ + swstack->return_ip = (unsigned long) ret_from_fork; + + /* Fix the user-mode and kernel-mode stackpointer. */ + p->thread.usp = usp; + p->thread.ksp = (unsigned long) swstack; + + 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); +} + +/* 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, + unsigned long tls, 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) +{ + /* TODO */ + return 0; +} +#undef last_sched +#undef first_sched + +void show_regs(struct pt_regs * regs) +{ + unsigned long usp = rdusp(); + printk("ERP: %08lx SRP: %08lx CCS: %08lx USP: %08lx MOF: %08lx\n", + regs->erp, regs->srp, regs->ccs, 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); +} |
