]>
Commit | Line | Data |
---|---|---|
687b12ba AJ |
1 | /* |
2 | * Port on Texas Instruments TMS320C6x architecture | |
3 | * | |
4 | * Copyright (C) 2004, 2006, 2009, 2010, 2011 Texas Instruments Incorporated | |
5 | * Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com) | |
6 | * | |
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. | |
10 | * | |
11 | */ | |
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> | |
29930025 | 20 | #include <linux/sched/task.h> |
687b12ba AJ |
21 | |
22 | #include <asm/syscalls.h> | |
23 | ||
24 | /* hooks for board specific support */ | |
25 | void (*c6x_restart)(void); | |
26 | void (*c6x_halt)(void); | |
27 | ||
28 | extern asmlinkage void ret_from_fork(void); | |
46f15067 | 29 | extern asmlinkage void ret_from_kernel_thread(void); |
687b12ba | 30 | |
687b12ba AJ |
31 | /* |
32 | * power off function, if any | |
33 | */ | |
34 | void (*pm_power_off)(void); | |
35 | EXPORT_SYMBOL(pm_power_off); | |
36 | ||
e46746cd | 37 | void arch_cpu_idle(void) |
687b12ba AJ |
38 | { |
39 | unsigned long tmp; | |
40 | ||
41 | /* | |
42 | * Put local_irq_enable and idle in same execute packet | |
43 | * to make them atomic and avoid race to idle with | |
44 | * interrupts enabled. | |
45 | */ | |
46 | asm volatile (" mvc .s2 CSR,%0\n" | |
47 | " or .d2 1,%0,%0\n" | |
48 | " mvc .s2 %0,CSR\n" | |
49 | "|| idle\n" | |
50 | : "=b"(tmp)); | |
51 | } | |
52 | ||
687b12ba AJ |
53 | static void halt_loop(void) |
54 | { | |
55 | printk(KERN_EMERG "System Halted, OK to turn off power\n"); | |
56 | local_irq_disable(); | |
57 | while (1) | |
58 | asm volatile("idle\n"); | |
59 | } | |
60 | ||
61 | void machine_restart(char *__unused) | |
62 | { | |
63 | if (c6x_restart) | |
64 | c6x_restart(); | |
65 | halt_loop(); | |
66 | } | |
67 | ||
68 | void machine_halt(void) | |
69 | { | |
70 | if (c6x_halt) | |
71 | c6x_halt(); | |
72 | halt_loop(); | |
73 | } | |
74 | ||
75 | void machine_power_off(void) | |
76 | { | |
77 | if (pm_power_off) | |
78 | pm_power_off(); | |
79 | halt_loop(); | |
80 | } | |
81 | ||
687b12ba AJ |
82 | void flush_thread(void) |
83 | { | |
84 | } | |
85 | ||
687b12ba AJ |
86 | /* |
87 | * Do necessary setup to start up a newly executed thread. | |
88 | */ | |
89 | void start_thread(struct pt_regs *regs, unsigned int pc, unsigned long usp) | |
90 | { | |
91 | /* | |
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. | |
96 | * | |
97 | * NB: Library startup code needs to match this. | |
98 | */ | |
99 | usp -= 8; | |
100 | ||
687b12ba AJ |
101 | regs->pc = pc; |
102 | regs->sp = usp; | |
103 | regs->tsr |= 0x40; /* set user mode */ | |
104 | current->thread.usp = usp; | |
105 | } | |
106 | ||
107 | /* | |
108 | * Copy a new thread context in its stack. | |
109 | */ | |
110 | int copy_thread(unsigned long clone_flags, unsigned long usp, | |
111 | unsigned long ustk_size, | |
afa86fc4 | 112 | struct task_struct *p) |
687b12ba AJ |
113 | { |
114 | struct pt_regs *childregs; | |
115 | ||
116 | childregs = task_pt_regs(p); | |
117 | ||
951b3961 | 118 | if (unlikely(p->flags & PF_KTHREAD)) { |
687b12ba | 119 | /* case of __kernel_thread: we return to supervisor space */ |
5687580b | 120 | memset(childregs, 0, sizeof(struct pt_regs)); |
687b12ba | 121 | childregs->sp = (unsigned long)(childregs + 1); |
46f15067 | 122 | p->thread.pc = (unsigned long) ret_from_kernel_thread; |
5687580b AV |
123 | childregs->a0 = usp; /* function */ |
124 | childregs->a1 = ustk_size; /* argument */ | |
46f15067 | 125 | } else { |
687b12ba | 126 | /* Otherwise use the given stack */ |
951b3961 AV |
127 | *childregs = *current_pt_regs(); |
128 | if (usp) | |
129 | childregs->sp = usp; | |
46f15067 MS |
130 | p->thread.pc = (unsigned long) ret_from_fork; |
131 | } | |
687b12ba AJ |
132 | |
133 | /* Set usp/ksp */ | |
134 | p->thread.usp = childregs->sp; | |
687b12ba | 135 | thread_saved_ksp(p) = (unsigned long)childregs - 8; |
46f15067 | 136 | p->thread.wchan = p->thread.pc; |
687b12ba AJ |
137 | #ifdef __DSBT__ |
138 | { | |
139 | unsigned long dp; | |
140 | ||
141 | asm volatile ("mv .S2 b14,%0\n" : "=b"(dp)); | |
142 | ||
143 | thread_saved_dp(p) = dp; | |
144 | if (usp == -1) | |
145 | childregs->dp = dp; | |
146 | } | |
147 | #endif | |
148 | return 0; | |
149 | } | |
150 | ||
687b12ba AJ |
151 | unsigned long get_wchan(struct task_struct *p) |
152 | { | |
153 | return p->thread.wchan; | |
154 | } |