| /* |
| * 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/sched.h> |
| #include <linux/slab.h> |
| #include <linux/err.h> |
| #include <linux/fs.h> |
| #include <hwregs/reg_rdwr.h> |
| #include <hwregs/reg_map.h> |
| #include <hwregs/timer_defs.h> |
| #include <hwregs/intr_vect_defs.h> |
| |
| extern void stop_watchdog(void); |
| |
| 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_timer0, 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 task_pt_regs(t)->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(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 = task_pt_regs(p); |
| *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)) { |
| task_thread_info(p)->tls = regs->mof; |
| } |
| |
| /* Put the switch stack right below the pt_regs. */ |
| swstack = ((struct switch_stack *) childregs) - 1; |
| |
| /* Parameter 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); |
| } |