1 files changed, 165 insertions, 0 deletions

diff --git a/arch/score/kernel/process.c b/arch/score/kernel/process.c
new file mode 100644
index 00000000000..aaa3085251f
--- /dev/null
+++ b/arch/score/kernel/process.c
@@ -0,0 +1,165 @@
+/*
+ * arch/score/kernel/process.c
+ *
+ * Score Processor version.
+ *
+ * Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
+ *  Chen Liqin <liqin.chen@sunplusct.com>
+ *  Lennox Wu <lennox.wu@sunplusct.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see the file COPYING, or write
+ * to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <linux/module.h>
+
+void (*pm_power_off)(void);
+EXPORT_SYMBOL(pm_power_off);
+
+/* If or when software machine-restart is implemented, add code here. */
+void machine_restart(char *command) {}
+
+/* If or when software machine-halt is implemented, add code here. */
+void machine_halt(void) {}
+
+/* If or when software machine-power-off is implemented, add code here. */
+void machine_power_off(void) {}
+
+/*
+ * The idle thread. There's no useful work to be
+ * done, so just try to conserve power and have a
+ * low exit latency (ie sit in a loop waiting for
+ * somebody to say that they'd like to reschedule)
+ */
+void __noreturn cpu_idle(void)
+{
+        /* endless idle loop with no priority at all */
+        while (1) {
+                while (!need_resched())
+                        barrier();
+
+                preempt_enable_no_resched();
+                schedule();
+                preempt_disable();
+        }
+}
+
+asmlinkage void ret_from_fork(void);
+
+void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp)
+{
+        unsigned long status;
+
+        /* New thread loses kernel privileges. */
+        status = regs->cp0_psr & ~(KU_MASK);
+        status |= KU_USER;
+        regs->cp0_psr = status;
+        regs->cp0_epc = pc;
+        regs->regs[0] = sp;
+}
+
+void exit_thread(void) {}
+
+/*
+ * When a process does an "exec", machine state like FPU and debug
+ * registers need to be reset.  This is a hook function for that.
+ * Currently we don't have any such state to reset, so this is empty.
+ */
+void flush_thread(void) {}
+
+/*
+ * set up the kernel stack and exception frames for a new process
+ */
+int copy_thread(unsigned long clone_flags, unsigned long usp,
+                unsigned long unused,
+                struct task_struct *p, struct pt_regs *regs)
+{
+        struct thread_info *ti = task_thread_info(p);
+        struct pt_regs *childregs = task_pt_regs(p);
+
+        p->set_child_tid = NULL;
+        p->clear_child_tid = NULL;
+
+        *childregs = *regs;
+        childregs->regs[7] = 0;         /* Clear error flag */
+        childregs->regs[4] = 0;         /* Child gets zero as return value */
+        regs->regs[4] = p->pid;
+
+        if (childregs->cp0_psr & 0x8) { /* test kernel fork or user fork */
+                childregs->regs[0] = usp;               /* user fork */
+        } else {
+                childregs->regs[28] = (unsigned long) ti; /* kernel fork */
+                childregs->regs[0] = (unsigned long) childregs;
+        }
+
+        p->thread.reg0 = (unsigned long) childregs;
+        p->thread.reg3 = (unsigned long) ret_from_fork;
+        p->thread.cp0_psr = 0;
+
+        return 0;
+}
+
+/* Fill in the fpu structure for a core dump. */
+int dump_fpu(struct pt_regs *regs, elf_fpregset_t *r)
+{
+        return 1;
+}
+
+static void __noreturn
+kernel_thread_helper(void *unused0, int (*fn)(void *),
+                 void *arg, void *unused1)
+{
+        do_exit(fn(arg));
+}
+
+/*
+ * Create a kernel thread.
+ */
+long kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
+{
+        struct pt_regs regs;
+
+        memset(&regs, 0, sizeof(regs));
+
+        regs.regs[6] = (unsigned long) arg;
+        regs.regs[5] = (unsigned long) fn;
+        regs.cp0_epc = (unsigned long) kernel_thread_helper;
+        regs.cp0_psr = (regs.cp0_psr & ~(0x1|0x4|0x8)) | \
+                        ((regs.cp0_psr & 0x3) << 2);
+
+        return do_fork(flags | CLONE_VM | CLONE_UNTRACED, \
+                        0, &regs, 0, NULL, NULL);
+}
+
+unsigned long thread_saved_pc(struct task_struct *tsk)
+{
+        return task_pt_regs(tsk)->cp0_epc;
+}
+
+unsigned long get_wchan(struct task_struct *task)
+{
+        if (!task || task == current || task->state == TASK_RUNNING)
+                return 0;
+
+        if (!task_stack_page(task))
+                return 0;
+
+        return task_pt_regs(task)->cp0_epc;
+}
+
+unsigned long arch_align_stack(unsigned long sp)
+{
+        return sp;
+}