2770d9a9a84edbc4d66b9cbae3e39aff8f001d38
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>
21 #include <asm/syscalls.h>
23 /* hooks for board specific support */
24 void (*c6x_restart
)(void);
25 void (*c6x_halt
)(void);
27 extern asmlinkage
void ret_from_fork(void);
28 extern asmlinkage
void ret_from_kernel_thread(void);
31 * power off function, if any
33 void (*pm_power_off
)(void);
34 EXPORT_SYMBOL(pm_power_off
);
36 static void c6x_idle(void)
41 * Put local_irq_enable and idle in same execute packet
42 * to make them atomic and avoid race to idle with
45 asm volatile (" mvc .s2 CSR,%0\n"
53 * The idle loop for C64x
57 /* endless idle loop with no priority at all */
59 tick_nohz_idle_enter();
67 c6x_idle(); /* enables local irqs */
70 tick_nohz_idle_exit();
72 preempt_enable_no_resched();
78 static void halt_loop(void)
80 printk(KERN_EMERG
"System Halted, OK to turn off power\n");
83 asm volatile("idle\n");
86 void machine_restart(char *__unused
)
93 void machine_halt(void)
100 void machine_power_off(void)
107 void flush_thread(void)
111 void exit_thread(void)
115 SYSCALL_DEFINE1(c6x_clone
, struct pt_regs
*, regs
)
117 unsigned long clone_flags
;
120 /* syscall puts clone_flags in A4 and usp in B4 */
121 clone_flags
= regs
->orig_a4
;
127 return do_fork(clone_flags
, newsp
, regs
, 0, (int __user
*)regs
->a6
,
128 (int __user
*)regs
->b6
);
132 * Do necessary setup to start up a newly executed thread.
134 void start_thread(struct pt_regs
*regs
, unsigned int pc
, unsigned long usp
)
137 * The binfmt loader will setup a "full" stack, but the C6X
138 * operates an "empty" stack. So we adjust the usp so that
139 * argc doesn't get destroyed if an interrupt is taken before
140 * it is read from the stack.
142 * NB: Library startup code needs to match this.
149 regs
->tsr
|= 0x40; /* set user mode */
150 current
->thread
.usp
= usp
;
154 * Copy a new thread context in its stack.
156 int copy_thread(unsigned long clone_flags
, unsigned long usp
,
157 unsigned long ustk_size
,
158 struct task_struct
*p
, struct pt_regs
*regs
)
160 struct pt_regs
*childregs
;
162 childregs
= task_pt_regs(p
);
165 /* case of __kernel_thread: we return to supervisor space */
166 memset(childregs
, 0, sizeof(struct pt_regs
));
167 childregs
->sp
= (unsigned long)(childregs
+ 1);
168 p
->thread
.pc
= (unsigned long) ret_from_kernel_thread
;
169 childregs
->a0
= usp
; /* function */
170 childregs
->a1
= ustk_size
; /* argument */
172 /* Otherwise use the given stack */
175 p
->thread
.pc
= (unsigned long) ret_from_fork
;
179 p
->thread
.usp
= childregs
->sp
;
180 thread_saved_ksp(p
) = (unsigned long)childregs
- 8;
181 p
->thread
.wchan
= p
->thread
.pc
;
186 asm volatile ("mv .S2 b14,%0\n" : "=b"(dp
));
188 thread_saved_dp(p
) = dp
;
196 unsigned long get_wchan(struct task_struct
*p
)
198 return p
->thread
.wchan
;
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