score: Add support for Sunplus S+core architecture

This is the complete set of new arch Score's files for linux.
Score instruction set support 16bits, 32bits and 64bits instruction,
Score SOC had been used in game machine and LCD TV.

Signed-off-by: Chen Liqin <liqin.chen@sunplusct.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

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 000000000000..aaa3085251fa
--- /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;
+}