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authorGuanXuetao <gxt@mprc.pku.edu.cn>2011-01-15 05:16:21 -0500
committerGuanXuetao <gxt@mprc.pku.edu.cn>2011-03-16 21:19:07 -0400
commitf73670e8a55c11d47c28dca35dc4bc7dfbd4e6eb (patch)
treebcf5641d487714be3a1317099769cecbedf4be85
parent141c943fd4b323bae2b47f67743dba96134afb1f (diff)
unicore32 core architecture: process/thread related codes
This patch implements process/thread related codes. Backtrace and stacktrace are here. Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Diffstat
-rw-r--r--arch/unicore32/include/asm/stacktrace.h31
-rw-r--r--arch/unicore32/include/asm/thread_info.h154
-rw-r--r--arch/unicore32/kernel/init_task.c44
-rw-r--r--arch/unicore32/kernel/process.c389
-rw-r--r--arch/unicore32/kernel/stacktrace.c131
-rw-r--r--arch/unicore32/lib/backtrace.S163
6 files changed, 912 insertions, 0 deletions
diff --git a/arch/unicore32/include/asm/stacktrace.h b/arch/unicore32/include/asm/stacktrace.h
new file mode 100644
index 000000000000..76edc65a5871
--- /dev/null
+++ b/arch/unicore32/include/asm/stacktrace.h
@@ -0,0 +1,31 @@
1/*
2 * linux/arch/unicore32/include/asm/stacktrace.h
3 *
4 * Code specific to PKUnity SoC and UniCore ISA
5 *
6 * Copyright (C) 2001-2010 GUAN Xue-tao
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#ifndef __UNICORE_STACKTRACE_H__
14#define __UNICORE_STACKTRACE_H__
15
16struct stackframe {
17 unsigned long fp;
18 unsigned long sp;
19 unsigned long lr;
20 unsigned long pc;
21};
22
23#ifdef CONFIG_FRAME_POINTER
24extern int unwind_frame(struct stackframe *frame);
25#else
26#define unwind_frame(f) (-EINVAL)
27#endif
28extern void walk_stackframe(struct stackframe *frame,
29 int (*fn)(struct stackframe *, void *), void *data);
30
31#endif /* __UNICORE_STACKTRACE_H__ */
diff --git a/arch/unicore32/include/asm/thread_info.h b/arch/unicore32/include/asm/thread_info.h
new file mode 100644
index 000000000000..c270e9e04861
--- /dev/null
+++ b/arch/unicore32/include/asm/thread_info.h
@@ -0,0 +1,154 @@
1/*
2 * linux/arch/unicore32/include/asm/thread_info.h
3 *
4 * Code specific to PKUnity SoC and UniCore ISA
5 *
6 * Copyright (C) 2001-2010 GUAN Xue-tao
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12#ifndef __UNICORE_THREAD_INFO_H__
13#define __UNICORE_THREAD_INFO_H__
14
15#ifdef __KERNEL__
16
17#include <linux/compiler.h>
18#include <asm/fpstate.h>
19
20#define THREAD_SIZE_ORDER 1
21#define THREAD_SIZE 8192
22#define THREAD_START_SP (THREAD_SIZE - 8)
23
24#ifndef __ASSEMBLY__
25
26struct task_struct;
27struct exec_domain;
28
29#include <asm/types.h>
30
31typedef struct {
32 unsigned long seg;
33} mm_segment_t;
34
35struct cpu_context_save {
36 __u32 r4;
37 __u32 r5;
38 __u32 r6;
39 __u32 r7;
40 __u32 r8;
41 __u32 r9;
42 __u32 r10;
43 __u32 r11;
44 __u32 r12;
45 __u32 r13;
46 __u32 r14;
47 __u32 r15;
48 __u32 r16;
49 __u32 r17;
50 __u32 r18;
51 __u32 r19;
52 __u32 r20;
53 __u32 r21;
54 __u32 r22;
55 __u32 r23;
56 __u32 r24;
57 __u32 r25;
58 __u32 r26;
59 __u32 fp;
60 __u32 sp;
61 __u32 pc;
62};
63
64/*
65 * low level task data that entry.S needs immediate access to.
66 * __switch_to() assumes cpu_context follows immediately after cpu_domain.
67 */
68struct thread_info {
69 unsigned long flags; /* low level flags */
70 int preempt_count; /* 0 => preemptable */
71 /* <0 => bug */
72 mm_segment_t addr_limit; /* address limit */
73 struct task_struct *task; /* main task structure */
74 struct exec_domain *exec_domain; /* execution domain */
75 __u32 cpu; /* cpu */
76 struct cpu_context_save cpu_context; /* cpu context */
77 __u32 syscall; /* syscall number */
78 __u8 used_cp[16]; /* thread used copro */
79#ifdef CONFIG_UNICORE_FPU_F64
80 struct fp_state fpstate __attribute__((aligned(8)));
81#endif
82 struct restart_block restart_block;
83};
84
85#define INIT_THREAD_INFO(tsk) \
86{ \
87 .task = &tsk, \
88 .exec_domain = &default_exec_domain, \
89 .flags = 0, \
90 .preempt_count = INIT_PREEMPT_COUNT, \
91 .addr_limit = KERNEL_DS, \
92 .restart_block = { \
93 .fn = do_no_restart_syscall, \
94 }, \
95}
96
97#define init_thread_info (init_thread_union.thread_info)
98#define init_stack (init_thread_union.stack)
99
100/*
101 * how to get the thread information struct from C
102 */
103static inline struct thread_info *current_thread_info(void) __attribute_const__;
104
105static inline struct thread_info *current_thread_info(void)
106{
107 register unsigned long sp asm ("sp");
108 return (struct thread_info *)(sp & ~(THREAD_SIZE - 1));
109}
110
111#define thread_saved_pc(tsk) \
112 ((unsigned long)(task_thread_info(tsk)->cpu_context.pc))
113#define thread_saved_sp(tsk) \
114 ((unsigned long)(task_thread_info(tsk)->cpu_context.sp))
115#define thread_saved_fp(tsk) \
116 ((unsigned long)(task_thread_info(tsk)->cpu_context.fp))
117
118#endif
119
120/*
121 * We use bit 30 of the preempt_count to indicate that kernel
122 * preemption is occurring. See <asm/hardirq.h>.
123 */
124#define PREEMPT_ACTIVE 0x40000000
125
126/*
127 * thread information flags:
128 * TIF_SYSCALL_TRACE - syscall trace active
129 * TIF_SIGPENDING - signal pending
130 * TIF_NEED_RESCHED - rescheduling necessary
131 * TIF_NOTIFY_RESUME - callback before returning to user
132 */
133#define TIF_SIGPENDING 0
134#define TIF_NEED_RESCHED 1
135#define TIF_NOTIFY_RESUME 2 /* callback before returning to user */
136#define TIF_SYSCALL_TRACE 8
137#define TIF_MEMDIE 18
138#define TIF_FREEZE 19
139#define TIF_RESTORE_SIGMASK 20
140
141#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
142#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
143#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
144#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
145#define _TIF_FREEZE (1 << TIF_FREEZE)
146#define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK)
147
148/*
149 * Change these and you break ASM code in entry-common.S
150 */
151#define _TIF_WORK_MASK 0x000000ff
152
153#endif /* __KERNEL__ */
154#endif /* __UNICORE_THREAD_INFO_H__ */
diff --git a/arch/unicore32/kernel/init_task.c b/arch/unicore32/kernel/init_task.c
new file mode 100644
index 000000000000..a35a1e50e4f4
--- /dev/null
+++ b/arch/unicore32/kernel/init_task.c
@@ -0,0 +1,44 @@
1/*
2 * linux/arch/unicore32/kernel/init_task.c
3 *
4 * Code specific to PKUnity SoC and UniCore ISA
5 *
6 * Copyright (C) 2001-2010 GUAN Xue-tao
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12#include <linux/mm.h>
13#include <linux/module.h>
14#include <linux/fs.h>
15#include <linux/sched.h>
16#include <linux/init.h>
17#include <linux/init_task.h>
18#include <linux/mqueue.h>
19#include <linux/uaccess.h>
20
21#include <asm/pgtable.h>
22
23static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
24static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
25/*
26 * Initial thread structure.
27 *
28 * We need to make sure that this is 8192-byte aligned due to the
29 * way process stacks are handled. This is done by making sure
30 * the linker maps this in the .text segment right after head.S,
31 * and making head.S ensure the proper alignment.
32 *
33 * The things we do for performance..
34 */
35union thread_union init_thread_union __init_task_data = {
36 INIT_THREAD_INFO(init_task) };
37
38/*
39 * Initial task structure.
40 *
41 * All other task structs will be allocated on slabs in fork.c
42 */
43struct task_struct init_task = INIT_TASK(init_task);
44EXPORT_SYMBOL(init_task);
diff --git a/arch/unicore32/kernel/process.c b/arch/unicore32/kernel/process.c
new file mode 100644
index 000000000000..8d4a273ae086
--- /dev/null
+++ b/arch/unicore32/kernel/process.c
@@ -0,0 +1,389 @@
1/*
2 * linux/arch/unicore32/kernel/process.c
3 *
4 * Code specific to PKUnity SoC and UniCore ISA
5 *
6 * Copyright (C) 2001-2010 GUAN Xue-tao
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12#include <stdarg.h>
13
14#include <linux/module.h>
15#include <linux/sched.h>
16#include <linux/kernel.h>
17#include <linux/mm.h>
18#include <linux/stddef.h>
19#include <linux/unistd.h>
20#include <linux/delay.h>
21#include <linux/reboot.h>
22#include <linux/interrupt.h>
23#include <linux/kallsyms.h>
24#include <linux/init.h>
25#include <linux/cpu.h>
26#include <linux/elfcore.h>
27#include <linux/pm.h>
28#include <linux/tick.h>
29#include <linux/utsname.h>
30#include <linux/uaccess.h>
31#include <linux/random.h>
32#include <linux/gpio.h>
33#include <linux/stacktrace.h>
34
35#include <asm/cacheflush.h>
36#include <asm/processor.h>
37#include <asm/system.h>
38#include <asm/stacktrace.h>
39
40#include "setup.h"
41
42static const char * const processor_modes[] = {
43 "UK00", "UK01", "UK02", "UK03", "UK04", "UK05", "UK06", "UK07",
44 "UK08", "UK09", "UK0A", "UK0B", "UK0C", "UK0D", "UK0E", "UK0F",
45 "USER", "REAL", "INTR", "PRIV", "UK14", "UK15", "UK16", "ABRT",
46 "UK18", "UK19", "UK1A", "EXTN", "UK1C", "UK1D", "UK1E", "SUSR"
47};
48
49/*
50 * The idle thread, has rather strange semantics for calling pm_idle,
51 * but this is what x86 does and we need to do the same, so that
52 * things like cpuidle get called in the same way.
53 */
54void cpu_idle(void)
55{
56 /* endless idle loop with no priority at all */
57 while (1) {
58 tick_nohz_stop_sched_tick(1);
59 while (!need_resched()) {
60 local_irq_disable();
61 stop_critical_timings();
62 cpu_do_idle();
63 local_irq_enable();
64 start_critical_timings();
65 }
66 tick_nohz_restart_sched_tick();
67 preempt_enable_no_resched();
68 schedule();
69 preempt_disable();
70 }
71}
72
73static char reboot_mode = 'h';
74
75int __init reboot_setup(char *str)
76{
77 reboot_mode = str[0];
78 return 1;
79}
80
81__setup("reboot=", reboot_setup);
82
83void machine_halt(void)
84{
85 gpio_set_value(GPO_SOFT_OFF, 0);
86}
87
88/*
89 * Function pointers to optional machine specific functions
90 */
91void (*pm_power_off)(void) = NULL;
92
93void machine_power_off(void)
94{
95 if (pm_power_off)
96 pm_power_off();
97 machine_halt();
98}
99
100void machine_restart(char *cmd)
101{
102 /* Disable interrupts first */
103 local_irq_disable();
104
105 /*
106 * Tell the mm system that we are going to reboot -
107 * we may need it to insert some 1:1 mappings so that
108 * soft boot works.
109 */
110 setup_mm_for_reboot(reboot_mode);
111
112 /* Clean and invalidate caches */
113 flush_cache_all();
114
115 /* Turn off caching */
116 cpu_proc_fin();
117
118 /* Push out any further dirty data, and ensure cache is empty */
119 flush_cache_all();
120
121 /*
122 * Now handle reboot code.
123 */
124 if (reboot_mode == 's') {
125 /* Jump into ROM at address 0xffff0000 */
126 cpu_reset(VECTORS_BASE);
127 } else {
128 PM_PLLSYSCFG = 0x00002001; /* cpu clk = 250M */
129 PM_PLLDDRCFG = 0x00100800; /* ddr clk = 44M */
130 PM_PLLVGACFG = 0x00002001; /* vga clk = 250M */
131
132 /* Use on-chip reset capability */
133 /* following instructions must be in one icache line */
134 __asm__ __volatile__(
135 " .align 5\n\t"
136 " stw %1, [%0]\n\t"
137 "201: ldw r0, [%0]\n\t"
138 " cmpsub.a r0, #0\n\t"
139 " bne 201b\n\t"
140 " stw %3, [%2]\n\t"
141 " nop; nop; nop\n\t"
142 /* prefetch 3 instructions at most */
143 :
144 : "r" ((unsigned long)&PM_PMCR),
145 "r" (PM_PMCR_CFBSYS | PM_PMCR_CFBDDR
146 | PM_PMCR_CFBVGA),
147 "r" ((unsigned long)&RESETC_SWRR),
148 "r" (RESETC_SWRR_SRB)
149 : "r0", "memory");
150 }
151
152 /*
153 * Whoops - the architecture was unable to reboot.
154 * Tell the user!
155 */
156 mdelay(1000);
157 printk(KERN_EMERG "Reboot failed -- System halted\n");
158 do { } while (1);
159}
160
161void __show_regs(struct pt_regs *regs)
162{
163 unsigned long flags;
164 char buf[64];
165
166 printk(KERN_DEFAULT "CPU: %d %s (%s %.*s)\n",
167 raw_smp_processor_id(), print_tainted(),
168 init_utsname()->release,
169 (int)strcspn(init_utsname()->version, " "),
170 init_utsname()->version);
171 print_symbol("PC is at %s\n", instruction_pointer(regs));
172 print_symbol("LR is at %s\n", regs->UCreg_lr);
173 printk(KERN_DEFAULT "pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
174 "sp : %08lx ip : %08lx fp : %08lx\n",
175 regs->UCreg_pc, regs->UCreg_lr, regs->UCreg_asr,
176 regs->UCreg_sp, regs->UCreg_ip, regs->UCreg_fp);
177 printk(KERN_DEFAULT "r26: %08lx r25: %08lx r24: %08lx\n",
178 regs->UCreg_26, regs->UCreg_25,
179 regs->UCreg_24);
180 printk(KERN_DEFAULT "r23: %08lx r22: %08lx r21: %08lx r20: %08lx\n",
181 regs->UCreg_23, regs->UCreg_22,
182 regs->UCreg_21, regs->UCreg_20);
183 printk(KERN_DEFAULT "r19: %08lx r18: %08lx r17: %08lx r16: %08lx\n",
184 regs->UCreg_19, regs->UCreg_18,
185 regs->UCreg_17, regs->UCreg_16);
186 printk(KERN_DEFAULT "r15: %08lx r14: %08lx r13: %08lx r12: %08lx\n",
187 regs->UCreg_15, regs->UCreg_14,
188 regs->UCreg_13, regs->UCreg_12);
189 printk(KERN_DEFAULT "r11: %08lx r10: %08lx r9 : %08lx r8 : %08lx\n",
190 regs->UCreg_11, regs->UCreg_10,
191 regs->UCreg_09, regs->UCreg_08);
192 printk(KERN_DEFAULT "r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
193 regs->UCreg_07, regs->UCreg_06,
194 regs->UCreg_05, regs->UCreg_04);
195 printk(KERN_DEFAULT "r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
196 regs->UCreg_03, regs->UCreg_02,
197 regs->UCreg_01, regs->UCreg_00);
198
199 flags = regs->UCreg_asr;
200 buf[0] = flags & PSR_S_BIT ? 'S' : 's';
201 buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
202 buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
203 buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
204 buf[4] = '\0';
205
206 printk(KERN_DEFAULT "Flags: %s INTR o%s REAL o%s Mode %s Segment %s\n",
207 buf, interrupts_enabled(regs) ? "n" : "ff",
208 fast_interrupts_enabled(regs) ? "n" : "ff",
209 processor_modes[processor_mode(regs)],
210 segment_eq(get_fs(), get_ds()) ? "kernel" : "user");
211 {
212 unsigned int ctrl;
213
214 buf[0] = '\0';
215 {
216 unsigned int transbase;
217 asm("movc %0, p0.c2, #0\n"
218 : "=r" (transbase));
219 snprintf(buf, sizeof(buf), " Table: %08x", transbase);
220 }
221 asm("movc %0, p0.c1, #0\n" : "=r" (ctrl));
222
223 printk(KERN_DEFAULT "Control: %08x%s\n", ctrl, buf);
224 }
225}
226
227void show_regs(struct pt_regs *regs)
228{
229 printk(KERN_DEFAULT "\n");
230 printk(KERN_DEFAULT "Pid: %d, comm: %20s\n",
231 task_pid_nr(current), current->comm);
232 __show_regs(regs);
233 __backtrace();
234}
235
236/*
237 * Free current thread data structures etc..
238 */
239void exit_thread(void)
240{
241}
242
243void flush_thread(void)
244{
245 struct thread_info *thread = current_thread_info();
246 struct task_struct *tsk = current;
247
248 memset(thread->used_cp, 0, sizeof(thread->used_cp));
249 memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
250#ifdef CONFIG_UNICORE_FPU_F64
251 memset(&thread->fpstate, 0, sizeof(struct fp_state));
252#endif
253}
254
255void release_thread(struct task_struct *dead_task)
256{
257}
258
259asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
260
261int
262copy_thread(unsigned long clone_flags, unsigned long stack_start,
263 unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
264{
265 struct thread_info *thread = task_thread_info(p);
266 struct pt_regs *childregs = task_pt_regs(p);
267
268 *childregs = *regs;
269 childregs->UCreg_00 = 0;
270 childregs->UCreg_sp = stack_start;
271
272 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
273 thread->cpu_context.sp = (unsigned long)childregs;
274 thread->cpu_context.pc = (unsigned long)ret_from_fork;
275
276 if (clone_flags & CLONE_SETTLS)
277 childregs->UCreg_16 = regs->UCreg_03;
278
279 return 0;
280}
281
282/*
283 * Fill in the task's elfregs structure for a core dump.
284 */
285int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
286{
287 elf_core_copy_regs(elfregs, task_pt_regs(t));
288 return 1;
289}
290
291/*
292 * fill in the fpe structure for a core dump...
293 */
294int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fp)
295{
296 struct thread_info *thread = current_thread_info();
297 int used_math = thread->used_cp[1] | thread->used_cp[2];
298
299#ifdef CONFIG_UNICORE_FPU_F64
300 if (used_math)
301 memcpy(fp, &thread->fpstate, sizeof(*fp));
302#endif
303 return used_math != 0;
304}
305EXPORT_SYMBOL(dump_fpu);
306
307/*
308 * Shuffle the argument into the correct register before calling the
309 * thread function. r1 is the thread argument, r2 is the pointer to
310 * the thread function, and r3 points to the exit function.
311 */
312asm(".pushsection .text\n"
313" .align\n"
314" .type kernel_thread_helper, #function\n"
315"kernel_thread_helper:\n"
316" mov.a asr, r7\n"
317" mov r0, r4\n"
318" mov lr, r6\n"
319" mov pc, r5\n"
320" .size kernel_thread_helper, . - kernel_thread_helper\n"
321" .popsection");
322
323/*
324 * Create a kernel thread.
325 */
326pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
327{
328 struct pt_regs regs;
329
330 memset(&regs, 0, sizeof(regs));
331
332 regs.UCreg_04 = (unsigned long)arg;
333 regs.UCreg_05 = (unsigned long)fn;
334 regs.UCreg_06 = (unsigned long)do_exit;
335 regs.UCreg_07 = PRIV_MODE;
336 regs.UCreg_pc = (unsigned long)kernel_thread_helper;
337 regs.UCreg_asr = regs.UCreg_07 | PSR_I_BIT;
338
339 return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
340}
341EXPORT_SYMBOL(kernel_thread);
342
343unsigned long get_wchan(struct task_struct *p)
344{
345 struct stackframe frame;
346 int count = 0;
347 if (!p || p == current || p->state == TASK_RUNNING)
348 return 0;
349
350 frame.fp = thread_saved_fp(p);
351 frame.sp = thread_saved_sp(p);
352 frame.lr = 0; /* recovered from the stack */
353 frame.pc = thread_saved_pc(p);
354 do {
355 int ret = unwind_frame(&frame);
356 if (ret < 0)
357 return 0;
358 if (!in_sched_functions(frame.pc))
359 return frame.pc;
360 } while ((count++) < 16);
361 return 0;
362}
363
364unsigned long arch_randomize_brk(struct mm_struct *mm)
365{
366 unsigned long range_end = mm->brk + 0x02000000;
367 return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
368}
369
370/*
371 * The vectors page is always readable from user space for the
372 * atomic helpers and the signal restart code. Let's declare a mapping
373 * for it so it is visible through ptrace and /proc/<pid>/mem.
374 */
375
376int vectors_user_mapping(void)
377{
378 struct mm_struct *mm = current->mm;
379 return install_special_mapping(mm, 0xffff0000, PAGE_SIZE,
380 VM_READ | VM_EXEC |
381 VM_MAYREAD | VM_MAYEXEC |
382 VM_ALWAYSDUMP | VM_RESERVED,
383 NULL);
384}
385
386const char *arch_vma_name(struct vm_area_struct *vma)
387{
388 return (vma->vm_start == 0xffff0000) ? "[vectors]" : NULL;
389}
diff --git a/arch/unicore32/kernel/stacktrace.c b/arch/unicore32/kernel/stacktrace.c
new file mode 100644
index 000000000000..b34030bdabe3
--- /dev/null
+++ b/arch/unicore32/kernel/stacktrace.c
@@ -0,0 +1,131 @@
1/*
2 * linux/arch/unicore32/kernel/stacktrace.c
3 *
4 * Code specific to PKUnity SoC and UniCore ISA
5 *
6 * Copyright (C) 2001-2010 GUAN Xue-tao
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12#include <linux/module.h>
13#include <linux/sched.h>
14#include <linux/stacktrace.h>
15
16#include <asm/stacktrace.h>
17
18#if defined(CONFIG_FRAME_POINTER)
19/*
20 * Unwind the current stack frame and store the new register values in the
21 * structure passed as argument. Unwinding is equivalent to a function return,
22 * hence the new PC value rather than LR should be used for backtrace.
23 *
24 * With framepointer enabled, a simple function prologue looks like this:
25 * mov ip, sp
26 * stmdb sp!, {fp, ip, lr, pc}
27 * sub fp, ip, #4
28 *
29 * A simple function epilogue looks like this:
30 * ldm sp, {fp, sp, pc}
31 *
32 * Note that with framepointer enabled, even the leaf functions have the same
33 * prologue and epilogue, therefore we can ignore the LR value in this case.
34 */
35int notrace unwind_frame(struct stackframe *frame)
36{
37 unsigned long high, low;
38 unsigned long fp = frame->fp;
39
40 /* only go to a higher address on the stack */
41 low = frame->sp;
42 high = ALIGN(low, THREAD_SIZE);
43
44 /* check current frame pointer is within bounds */
45 if (fp < (low + 12) || fp + 4 >= high)
46 return -EINVAL;
47
48 /* restore the registers from the stack frame */
49 frame->fp = *(unsigned long *)(fp - 12);
50 frame->sp = *(unsigned long *)(fp - 8);
51 frame->pc = *(unsigned long *)(fp - 4);
52
53 return 0;
54}
55#endif
56
57void notrace walk_stackframe(struct stackframe *frame,
58 int (*fn)(struct stackframe *, void *), void *data)
59{
60 while (1) {
61 int ret;
62
63 if (fn(frame, data))
64 break;
65 ret = unwind_frame(frame);
66 if (ret < 0)
67 break;
68 }
69}
70EXPORT_SYMBOL(walk_stackframe);
71
72#ifdef CONFIG_STACKTRACE
73struct stack_trace_data {
74 struct stack_trace *trace;
75 unsigned int no_sched_functions;
76 unsigned int skip;
77};
78
79static int save_trace(struct stackframe *frame, void *d)
80{
81 struct stack_trace_data *data = d;
82 struct stack_trace *trace = data->trace;
83 unsigned long addr = frame->pc;
84
85 if (data->no_sched_functions && in_sched_functions(addr))
86 return 0;
87 if (data->skip) {
88 data->skip--;
89 return 0;
90 }
91
92 trace->entries[trace->nr_entries++] = addr;
93
94 return trace->nr_entries >= trace->max_entries;
95}
96
97void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
98{
99 struct stack_trace_data data;
100 struct stackframe frame;
101
102 data.trace = trace;
103 data.skip = trace->skip;
104
105 if (tsk != current) {
106 data.no_sched_functions = 1;
107 frame.fp = thread_saved_fp(tsk);
108 frame.sp = thread_saved_sp(tsk);
109 frame.lr = 0; /* recovered from the stack */
110 frame.pc = thread_saved_pc(tsk);
111 } else {
112 register unsigned long current_sp asm("sp");
113
114 data.no_sched_functions = 0;
115 frame.fp = (unsigned long)__builtin_frame_address(0);
116 frame.sp = current_sp;
117 frame.lr = (unsigned long)__builtin_return_address(0);
118 frame.pc = (unsigned long)save_stack_trace_tsk;
119 }
120
121 walk_stackframe(&frame, save_trace, &data);
122 if (trace->nr_entries < trace->max_entries)
123 trace->entries[trace->nr_entries++] = ULONG_MAX;
124}
125
126void save_stack_trace(struct stack_trace *trace)
127{
128 save_stack_trace_tsk(current, trace);
129}
130EXPORT_SYMBOL_GPL(save_stack_trace);
131#endif
diff --git a/arch/unicore32/lib/backtrace.S b/arch/unicore32/lib/backtrace.S
new file mode 100644
index 000000000000..ef01d77f2f65
--- /dev/null
+++ b/arch/unicore32/lib/backtrace.S
@@ -0,0 +1,163 @@
1/*
2 * linux/arch/unicore32/lib/backtrace.S
3 *
4 * Code specific to PKUnity SoC and UniCore ISA
5 *
6 * Copyright (C) 2001-2010 GUAN Xue-tao
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12#include <linux/linkage.h>
13#include <asm/assembler.h>
14 .text
15
16@ fp is 0 or stack frame
17
18#define frame v4
19#define sv_fp v5
20#define sv_pc v6
21#define offset v8
22
23ENTRY(__backtrace)
24 mov r0, fp
25
26ENTRY(c_backtrace)
27
28#if !defined(CONFIG_FRAME_POINTER) || !defined(CONFIG_PRINTK)
29 mov pc, lr
30ENDPROC(__backtrace)
31ENDPROC(c_backtrace)
32#else
33 stm.w (v4 - v8, lr), [sp-] @ Save an extra register
34 @ so we have a location...
35 mov.a frame, r0 @ if frame pointer is zero
36 beq no_frame @ we have no stack frames
37
381: stm.w (pc), [sp-] @ calculate offset of PC stored
39 ldw.w r0, [sp]+, #4 @ by stmfd for this CPU
40 adr r1, 1b
41 sub offset, r0, r1
42
43/*
44 * Stack frame layout:
45 * optionally saved caller registers (r4 - r10)
46 * saved fp
47 * saved sp
48 * saved lr
49 * frame => saved pc
50 * optionally saved arguments (r0 - r3)
51 * saved sp => <next word>
52 *
53 * Functions start with the following code sequence:
54 * mov ip, sp
55 * stm.w (r0 - r3), [sp-] (optional)
56 * corrected pc => stm.w sp, (..., fp, ip, lr, pc)
57 */
58for_each_frame:
59
601001: ldw sv_pc, [frame+], #0 @ get saved pc
611002: ldw sv_fp, [frame+], #-12 @ get saved fp
62
63 sub sv_pc, sv_pc, offset @ Correct PC for prefetching
64
651003: ldw r2, [sv_pc+], #-4 @ if stmfd sp, {args} exists,
66 ldw r3, .Ldsi+4 @ adjust saved 'pc' back one
67 cxor.a r3, r2 >> #14 @ instruction
68 beq 201f
69 sub r0, sv_pc, #4 @ allow for mov
70 b 202f
71201:
72 sub r0, sv_pc, #8 @ allow for mov + stmia
73202:
74 ldw r1, [frame+], #-4 @ get saved lr
75 mov r2, frame
76 b.l dump_backtrace_entry
77
78 ldw r1, [sv_pc+], #-4 @ if stmfd sp, {args} exists,
79 ldw r3, .Ldsi+4
80 cxor.a r3, r1 >> #14
81 bne 1004f
82 ldw r0, [frame+], #-8 @ get sp
83 sub r0, r0, #4 @ point at the last arg
84 b.l .Ldumpstm @ dump saved registers
85
861004: ldw r1, [sv_pc+], #0 @ if stmfd {, fp, ip, lr, pc}
87 ldw r3, .Ldsi @ instruction exists,
88 cxor.a r3, r1 >> #14
89 bne 201f
90 sub r0, frame, #16
91 b.l .Ldumpstm @ dump saved registers
92201:
93 cxor.a sv_fp, #0 @ zero saved fp means
94 beq no_frame @ no further frames
95
96 csub.a sv_fp, frame @ next frame must be
97 mov frame, sv_fp @ above the current frame
98 bua for_each_frame
99
1001006: adr r0, .Lbad
101 mov r1, frame
102 b.l printk
103no_frame: ldm.w (v4 - v8, pc), [sp]+
104ENDPROC(__backtrace)
105ENDPROC(c_backtrace)
106
107 .pushsection __ex_table,"a"
108 .align 3
109 .long 1001b, 1006b
110 .long 1002b, 1006b
111 .long 1003b, 1006b
112 .long 1004b, 1006b
113 .popsection
114
115#define instr v4
116#define reg v5
117#define stack v6
118
119.Ldumpstm: stm.w (instr, reg, stack, v7, lr), [sp-]
120 mov stack, r0
121 mov instr, r1
122 mov reg, #14
123 mov v7, #0
1241: mov r3, #1
125 csub.a reg, #8
126 bne 201f
127 sub reg, reg, #3
128201:
129 cand.a instr, r3 << reg
130 beq 2f
131 add v7, v7, #1
132 cxor.a v7, #6
133 cmoveq v7, #1
134 cmoveq r1, #'\n'
135 cmovne r1, #' '
136 ldw.w r3, [stack]+, #-4
137 mov r2, reg
138 csub.a r2, #8
139 bsl 201f
140 sub r2, r2, #3
141201:
142 cand.a instr, #0x40 @ if H is 1, high 16 regs
143 beq 201f
144 add r2, r2, #0x10 @ so r2 need add 16
145201:
146 adr r0, .Lfp
147 b.l printk
1482: sub.a reg, reg, #1
149 bns 1b
150 cxor.a v7, #0
151 beq 201f
152 adr r0, .Lcr
153 b.l printk
154201: ldm.w (instr, reg, stack, v7, pc), [sp]+
155
156.Lfp: .asciz "%cr%d:%08x"
157.Lcr: .asciz "\n"
158.Lbad: .asciz "Backtrace aborted due to bad frame pointer <%p>\n"
159 .align
160.Ldsi: .word 0x92eec000 >> 14 @ stm.w sp, (... fp, ip, lr, pc)
161 .word 0x92e10000 >> 14 @ stm.w sp, ()
162
163#endif
generated by cgit v1.2.2 (git 2.25.0) at 2026-01-19 23:22:00 -0500