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-rw-r--r--arch/cris/arch-v32/kernel/process.c270
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(&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.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, &regs, 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);
+}
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