1 files changed, 267 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 00000000..0570e8ce
--- /dev/null
+++ b/arch/cris/arch-v32/kernel/process.c
@@ -0,0 +1,267 @@
+/*
+ *  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(&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(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 because 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,
+	   const char *const *argv,
+	   const char *const *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);
+}