Root/arch/avr32/kernel/process.c

1/*
2 * Copyright (C) 2004-2006 Atmel Corporation
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8#include <linux/sched.h>
9#include <linux/module.h>
10#include <linux/kallsyms.h>
11#include <linux/fs.h>
12#include <linux/pm.h>
13#include <linux/ptrace.h>
14#include <linux/slab.h>
15#include <linux/reboot.h>
16#include <linux/tick.h>
17#include <linux/uaccess.h>
18#include <linux/unistd.h>
19
20#include <asm/sysreg.h>
21#include <asm/ocd.h>
22#include <asm/syscalls.h>
23
24#include <mach/pm.h>
25
26void (*pm_power_off)(void);
27EXPORT_SYMBOL(pm_power_off);
28
29/*
30 * This file handles the architecture-dependent parts of process handling..
31 */
32
33void arch_cpu_idle(void)
34{
35    cpu_enter_idle();
36}
37
38void machine_halt(void)
39{
40    /*
41     * Enter Stop mode. The 32 kHz oscillator will keep running so
42     * the RTC will keep the time properly and the system will
43     * boot quickly.
44     */
45    asm volatile("sleep 3\n\t"
46             "sub pc, -2");
47}
48
49void machine_power_off(void)
50{
51    if (pm_power_off)
52        pm_power_off();
53}
54
55void machine_restart(char *cmd)
56{
57    ocd_write(DC, (1 << OCD_DC_DBE_BIT));
58    ocd_write(DC, (1 << OCD_DC_RES_BIT));
59    while (1) ;
60}
61
62/*
63 * Free current thread data structures etc
64 */
65void exit_thread(void)
66{
67    ocd_disable(current);
68}
69
70void flush_thread(void)
71{
72    /* nothing to do */
73}
74
75void release_thread(struct task_struct *dead_task)
76{
77    /* do nothing */
78}
79
80static void dump_mem(const char *str, const char *log_lvl,
81             unsigned long bottom, unsigned long top)
82{
83    unsigned long p;
84    int i;
85
86    printk("%s%s(0x%08lx to 0x%08lx)\n", log_lvl, str, bottom, top);
87
88    for (p = bottom & ~31; p < top; ) {
89        printk("%s%04lx: ", log_lvl, p & 0xffff);
90
91        for (i = 0; i < 8; i++, p += 4) {
92            unsigned int val;
93
94            if (p < bottom || p >= top)
95                printk(" ");
96            else {
97                if (__get_user(val, (unsigned int __user *)p)) {
98                    printk("\n");
99                    goto out;
100                }
101                printk("%08x ", val);
102            }
103        }
104        printk("\n");
105    }
106
107out:
108    return;
109}
110
111static inline int valid_stack_ptr(struct thread_info *tinfo, unsigned long p)
112{
113    return (p > (unsigned long)tinfo)
114        && (p < (unsigned long)tinfo + THREAD_SIZE - 3);
115}
116
117#ifdef CONFIG_FRAME_POINTER
118static void show_trace_log_lvl(struct task_struct *tsk, unsigned long *sp,
119                   struct pt_regs *regs, const char *log_lvl)
120{
121    unsigned long lr, fp;
122    struct thread_info *tinfo;
123
124    if (regs)
125        fp = regs->r7;
126    else if (tsk == current)
127        asm("mov %0, r7" : "=r"(fp));
128    else
129        fp = tsk->thread.cpu_context.r7;
130
131    /*
132     * Walk the stack as long as the frame pointer (a) is within
133     * the kernel stack of the task, and (b) it doesn't move
134     * downwards.
135     */
136    tinfo = task_thread_info(tsk);
137    printk("%sCall trace:\n", log_lvl);
138    while (valid_stack_ptr(tinfo, fp)) {
139        unsigned long new_fp;
140
141        lr = *(unsigned long *)fp;
142#ifdef CONFIG_KALLSYMS
143        printk("%s [<%08lx>] ", log_lvl, lr);
144#else
145        printk(" [<%08lx>] ", lr);
146#endif
147        print_symbol("%s\n", lr);
148
149        new_fp = *(unsigned long *)(fp + 4);
150        if (new_fp <= fp)
151            break;
152        fp = new_fp;
153    }
154    printk("\n");
155}
156#else
157static void show_trace_log_lvl(struct task_struct *tsk, unsigned long *sp,
158                   struct pt_regs *regs, const char *log_lvl)
159{
160    unsigned long addr;
161
162    printk("%sCall trace:\n", log_lvl);
163
164    while (!kstack_end(sp)) {
165        addr = *sp++;
166        if (kernel_text_address(addr)) {
167#ifdef CONFIG_KALLSYMS
168            printk("%s [<%08lx>] ", log_lvl, addr);
169#else
170            printk(" [<%08lx>] ", addr);
171#endif
172            print_symbol("%s\n", addr);
173        }
174    }
175    printk("\n");
176}
177#endif
178
179void show_stack_log_lvl(struct task_struct *tsk, unsigned long sp,
180            struct pt_regs *regs, const char *log_lvl)
181{
182    struct thread_info *tinfo;
183
184    if (sp == 0) {
185        if (tsk)
186            sp = tsk->thread.cpu_context.ksp;
187        else
188            sp = (unsigned long)&tinfo;
189    }
190    if (!tsk)
191        tsk = current;
192
193    tinfo = task_thread_info(tsk);
194
195    if (valid_stack_ptr(tinfo, sp)) {
196        dump_mem("Stack: ", log_lvl, sp,
197             THREAD_SIZE + (unsigned long)tinfo);
198        show_trace_log_lvl(tsk, (unsigned long *)sp, regs, log_lvl);
199    }
200}
201
202void show_stack(struct task_struct *tsk, unsigned long *stack)
203{
204    show_stack_log_lvl(tsk, (unsigned long)stack, NULL, "");
205}
206
207static const char *cpu_modes[] = {
208    "Application", "Supervisor", "Interrupt level 0", "Interrupt level 1",
209    "Interrupt level 2", "Interrupt level 3", "Exception", "NMI"
210};
211
212void show_regs_log_lvl(struct pt_regs *regs, const char *log_lvl)
213{
214    unsigned long sp = regs->sp;
215    unsigned long lr = regs->lr;
216    unsigned long mode = (regs->sr & MODE_MASK) >> MODE_SHIFT;
217
218    show_regs_print_info(log_lvl);
219
220    if (!user_mode(regs)) {
221        sp = (unsigned long)regs + FRAME_SIZE_FULL;
222
223        printk("%s", log_lvl);
224        print_symbol("PC is at %s\n", instruction_pointer(regs));
225        printk("%s", log_lvl);
226        print_symbol("LR is at %s\n", lr);
227    }
228
229    printk("%spc : [<%08lx>] lr : [<%08lx>] %s\n"
230           "%ssp : %08lx r12: %08lx r11: %08lx\n",
231           log_lvl, instruction_pointer(regs), lr, print_tainted(),
232           log_lvl, sp, regs->r12, regs->r11);
233    printk("%sr10: %08lx r9 : %08lx r8 : %08lx\n",
234           log_lvl, regs->r10, regs->r9, regs->r8);
235    printk("%sr7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
236           log_lvl, regs->r7, regs->r6, regs->r5, regs->r4);
237    printk("%sr3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
238           log_lvl, regs->r3, regs->r2, regs->r1, regs->r0);
239    printk("%sFlags: %c%c%c%c%c\n", log_lvl,
240           regs->sr & SR_Q ? 'Q' : 'q',
241           regs->sr & SR_V ? 'V' : 'v',
242           regs->sr & SR_N ? 'N' : 'n',
243           regs->sr & SR_Z ? 'Z' : 'z',
244           regs->sr & SR_C ? 'C' : 'c');
245    printk("%sMode bits: %c%c%c%c%c%c%c%c%c%c\n", log_lvl,
246           regs->sr & SR_H ? 'H' : 'h',
247           regs->sr & SR_J ? 'J' : 'j',
248           regs->sr & SR_DM ? 'M' : 'm',
249           regs->sr & SR_D ? 'D' : 'd',
250           regs->sr & SR_EM ? 'E' : 'e',
251           regs->sr & SR_I3M ? '3' : '.',
252           regs->sr & SR_I2M ? '2' : '.',
253           regs->sr & SR_I1M ? '1' : '.',
254           regs->sr & SR_I0M ? '0' : '.',
255           regs->sr & SR_GM ? 'G' : 'g');
256    printk("%sCPU Mode: %s\n", log_lvl, cpu_modes[mode]);
257}
258
259void show_regs(struct pt_regs *regs)
260{
261    unsigned long sp = regs->sp;
262
263    if (!user_mode(regs))
264        sp = (unsigned long)regs + FRAME_SIZE_FULL;
265
266    show_regs_log_lvl(regs, "");
267    show_trace_log_lvl(current, (unsigned long *)sp, regs, "");
268}
269EXPORT_SYMBOL(show_regs);
270
271/* Fill in the fpu structure for a core dump. This is easy -- we don't have any */
272int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
273{
274    /* Not valid */
275    return 0;
276}
277
278asmlinkage void ret_from_fork(void);
279asmlinkage void ret_from_kernel_thread(void);
280asmlinkage void syscall_return(void);
281
282int copy_thread(unsigned long clone_flags, unsigned long usp,
283        unsigned long arg,
284        struct task_struct *p)
285{
286    struct pt_regs *childregs = task_pt_regs(p);
287
288    if (unlikely(p->flags & PF_KTHREAD)) {
289        memset(childregs, 0, sizeof(struct pt_regs));
290        p->thread.cpu_context.r0 = arg;
291        p->thread.cpu_context.r1 = usp; /* fn */
292        p->thread.cpu_context.r2 = (unsigned long)syscall_return;
293        p->thread.cpu_context.pc = (unsigned long)ret_from_kernel_thread;
294        childregs->sr = MODE_SUPERVISOR;
295    } else {
296        *childregs = *current_pt_regs();
297        if (usp)
298            childregs->sp = usp;
299        childregs->r12 = 0; /* Set return value for child */
300        p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
301    }
302
303    p->thread.cpu_context.sr = MODE_SUPERVISOR | SR_GM;
304    p->thread.cpu_context.ksp = (unsigned long)childregs;
305
306    clear_tsk_thread_flag(p, TIF_DEBUG);
307    if ((clone_flags & CLONE_PTRACE) && test_thread_flag(TIF_DEBUG))
308        ocd_enable(p);
309
310    return 0;
311}
312
313/*
314 * This function is supposed to answer the question "who called
315 * schedule()?"
316 */
317unsigned long get_wchan(struct task_struct *p)
318{
319    unsigned long pc;
320    unsigned long stack_page;
321
322    if (!p || p == current || p->state == TASK_RUNNING)
323        return 0;
324
325    stack_page = (unsigned long)task_stack_page(p);
326    BUG_ON(!stack_page);
327
328    /*
329     * The stored value of PC is either the address right after
330     * the call to __switch_to() or ret_from_fork.
331     */
332    pc = thread_saved_pc(p);
333    if (in_sched_functions(pc)) {
334#ifdef CONFIG_FRAME_POINTER
335        unsigned long fp = p->thread.cpu_context.r7;
336        BUG_ON(fp < stack_page || fp > (THREAD_SIZE + stack_page));
337        pc = *(unsigned long *)fp;
338#else
339        /*
340         * We depend on the frame size of schedule here, which
341         * is actually quite ugly. It might be possible to
342         * determine the frame size automatically at build
343         * time by doing this:
344         * - compile sched/core.c
345         * - disassemble the resulting sched.o
346         * - look for 'sub sp,??' shortly after '<schedule>:'
347         */
348        unsigned long sp = p->thread.cpu_context.ksp + 16;
349        BUG_ON(sp < stack_page || sp > (THREAD_SIZE + stack_page));
350        pc = *(unsigned long *)sp;
351#endif
352    }
353
354    return pc;
355}
356

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