2 * Port on Texas Instruments TMS320C6x architecture
4 * Copyright (C) 2004, 2006, 2009, 2010, 2011 Texas Instruments Incorporated
5 * Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
12 #include <linux/module.h>
13 #include <linux/unistd.h>
14 #include <linux/ptrace.h>
15 #include <linux/init_task.h>
16 #include <linux/tick.h>
17 #include <linux/mqueue.h>
18 #include <linux/syscalls.h>
19 #include <linux/reboot.h>
20 #include <linux/sched/task.h>
22 #include <asm/syscalls.h>
24 /* hooks for board specific support */
25 void (*c6x_restart)(void);
26 void (*c6x_halt)(void);
28 extern asmlinkage void ret_from_fork(void);
29 extern asmlinkage void ret_from_kernel_thread(void);
32 * power off function, if any
34 void (*pm_power_off)(void);
35 EXPORT_SYMBOL(pm_power_off);
37 void arch_cpu_idle(void)
42 * Put local_irq_enable and idle in same execute packet
43 * to make them atomic and avoid race to idle with
46 asm volatile (" mvc .s2 CSR,%0\n"
53 static void halt_loop(void)
55 printk(KERN_EMERG "System Halted, OK to turn off power\n");
58 asm volatile("idle\n");
61 void machine_restart(char *__unused)
68 void machine_halt(void)
75 void machine_power_off(void)
82 void flush_thread(void)
87 * Do necessary setup to start up a newly executed thread.
89 void start_thread(struct pt_regs *regs, unsigned int pc, unsigned long usp)
92 * The binfmt loader will setup a "full" stack, but the C6X
93 * operates an "empty" stack. So we adjust the usp so that
94 * argc doesn't get destroyed if an interrupt is taken before
95 * it is read from the stack.
97 * NB: Library startup code needs to match this.
103 regs->tsr |= 0x40; /* set user mode */
104 current->thread.usp = usp;
108 * Copy a new thread context in its stack.
110 int copy_thread(unsigned long clone_flags, unsigned long usp,
111 unsigned long ustk_size,
112 struct task_struct *p)
114 struct pt_regs *childregs;
116 childregs = task_pt_regs(p);
118 if (unlikely(p->flags & PF_KTHREAD)) {
119 /* case of __kernel_thread: we return to supervisor space */
120 memset(childregs, 0, sizeof(struct pt_regs));
121 childregs->sp = (unsigned long)(childregs + 1);
122 p->thread.pc = (unsigned long) ret_from_kernel_thread;
123 childregs->a0 = usp; /* function */
124 childregs->a1 = ustk_size; /* argument */
126 /* Otherwise use the given stack */
127 *childregs = *current_pt_regs();
130 p->thread.pc = (unsigned long) ret_from_fork;
134 p->thread.usp = childregs->sp;
135 thread_saved_ksp(p) = (unsigned long)childregs - 8;
136 p->thread.wchan = p->thread.pc;
141 asm volatile ("mv .S2 b14,%0\n" : "=b"(dp));
143 thread_saved_dp(p) = dp;
151 unsigned long get_wchan(struct task_struct *p)
153 return p->thread.wchan;