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>
This commit is contained in:
GuanXuetao 2011-01-15 18:16:21 +08:00
parent 141c943fd4
commit f73670e8a5
6 changed files with 912 additions and 0 deletions

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/*
* linux/arch/unicore32/include/asm/stacktrace.h
*
* Code specific to PKUnity SoC and UniCore ISA
*
* Copyright (C) 2001-2010 GUAN Xue-tao
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __UNICORE_STACKTRACE_H__
#define __UNICORE_STACKTRACE_H__
struct stackframe {
unsigned long fp;
unsigned long sp;
unsigned long lr;
unsigned long pc;
};
#ifdef CONFIG_FRAME_POINTER
extern int unwind_frame(struct stackframe *frame);
#else
#define unwind_frame(f) (-EINVAL)
#endif
extern void walk_stackframe(struct stackframe *frame,
int (*fn)(struct stackframe *, void *), void *data);
#endif /* __UNICORE_STACKTRACE_H__ */

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/*
* linux/arch/unicore32/include/asm/thread_info.h
*
* Code specific to PKUnity SoC and UniCore ISA
*
* Copyright (C) 2001-2010 GUAN Xue-tao
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __UNICORE_THREAD_INFO_H__
#define __UNICORE_THREAD_INFO_H__
#ifdef __KERNEL__
#include <linux/compiler.h>
#include <asm/fpstate.h>
#define THREAD_SIZE_ORDER 1
#define THREAD_SIZE 8192
#define THREAD_START_SP (THREAD_SIZE - 8)
#ifndef __ASSEMBLY__
struct task_struct;
struct exec_domain;
#include <asm/types.h>
typedef struct {
unsigned long seg;
} mm_segment_t;
struct cpu_context_save {
__u32 r4;
__u32 r5;
__u32 r6;
__u32 r7;
__u32 r8;
__u32 r9;
__u32 r10;
__u32 r11;
__u32 r12;
__u32 r13;
__u32 r14;
__u32 r15;
__u32 r16;
__u32 r17;
__u32 r18;
__u32 r19;
__u32 r20;
__u32 r21;
__u32 r22;
__u32 r23;
__u32 r24;
__u32 r25;
__u32 r26;
__u32 fp;
__u32 sp;
__u32 pc;
};
/*
* low level task data that entry.S needs immediate access to.
* __switch_to() assumes cpu_context follows immediately after cpu_domain.
*/
struct thread_info {
unsigned long flags; /* low level flags */
int preempt_count; /* 0 => preemptable */
/* <0 => bug */
mm_segment_t addr_limit; /* address limit */
struct task_struct *task; /* main task structure */
struct exec_domain *exec_domain; /* execution domain */
__u32 cpu; /* cpu */
struct cpu_context_save cpu_context; /* cpu context */
__u32 syscall; /* syscall number */
__u8 used_cp[16]; /* thread used copro */
#ifdef CONFIG_UNICORE_FPU_F64
struct fp_state fpstate __attribute__((aligned(8)));
#endif
struct restart_block restart_block;
};
#define INIT_THREAD_INFO(tsk) \
{ \
.task = &tsk, \
.exec_domain = &default_exec_domain, \
.flags = 0, \
.preempt_count = INIT_PREEMPT_COUNT, \
.addr_limit = KERNEL_DS, \
.restart_block = { \
.fn = do_no_restart_syscall, \
}, \
}
#define init_thread_info (init_thread_union.thread_info)
#define init_stack (init_thread_union.stack)
/*
* how to get the thread information struct from C
*/
static inline struct thread_info *current_thread_info(void) __attribute_const__;
static inline struct thread_info *current_thread_info(void)
{
register unsigned long sp asm ("sp");
return (struct thread_info *)(sp & ~(THREAD_SIZE - 1));
}
#define thread_saved_pc(tsk) \
((unsigned long)(task_thread_info(tsk)->cpu_context.pc))
#define thread_saved_sp(tsk) \
((unsigned long)(task_thread_info(tsk)->cpu_context.sp))
#define thread_saved_fp(tsk) \
((unsigned long)(task_thread_info(tsk)->cpu_context.fp))
#endif
/*
* We use bit 30 of the preempt_count to indicate that kernel
* preemption is occurring. See <asm/hardirq.h>.
*/
#define PREEMPT_ACTIVE 0x40000000
/*
* thread information flags:
* TIF_SYSCALL_TRACE - syscall trace active
* TIF_SIGPENDING - signal pending
* TIF_NEED_RESCHED - rescheduling necessary
* TIF_NOTIFY_RESUME - callback before returning to user
*/
#define TIF_SIGPENDING 0
#define TIF_NEED_RESCHED 1
#define TIF_NOTIFY_RESUME 2 /* callback before returning to user */
#define TIF_SYSCALL_TRACE 8
#define TIF_MEMDIE 18
#define TIF_FREEZE 19
#define TIF_RESTORE_SIGMASK 20
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_FREEZE (1 << TIF_FREEZE)
#define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK)
/*
* Change these and you break ASM code in entry-common.S
*/
#define _TIF_WORK_MASK 0x000000ff
#endif /* __KERNEL__ */
#endif /* __UNICORE_THREAD_INFO_H__ */

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/*
* linux/arch/unicore32/kernel/init_task.c
*
* Code specific to PKUnity SoC and UniCore ISA
*
* Copyright (C) 2001-2010 GUAN Xue-tao
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/init_task.h>
#include <linux/mqueue.h>
#include <linux/uaccess.h>
#include <asm/pgtable.h>
static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
/*
* Initial thread structure.
*
* We need to make sure that this is 8192-byte aligned due to the
* way process stacks are handled. This is done by making sure
* the linker maps this in the .text segment right after head.S,
* and making head.S ensure the proper alignment.
*
* The things we do for performance..
*/
union thread_union init_thread_union __init_task_data = {
INIT_THREAD_INFO(init_task) };
/*
* Initial task structure.
*
* All other task structs will be allocated on slabs in fork.c
*/
struct task_struct init_task = INIT_TASK(init_task);
EXPORT_SYMBOL(init_task);

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/*
* linux/arch/unicore32/kernel/process.c
*
* Code specific to PKUnity SoC and UniCore ISA
*
* Copyright (C) 2001-2010 GUAN Xue-tao
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <stdarg.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/delay.h>
#include <linux/reboot.h>
#include <linux/interrupt.h>
#include <linux/kallsyms.h>
#include <linux/init.h>
#include <linux/cpu.h>
#include <linux/elfcore.h>
#include <linux/pm.h>
#include <linux/tick.h>
#include <linux/utsname.h>
#include <linux/uaccess.h>
#include <linux/random.h>
#include <linux/gpio.h>
#include <linux/stacktrace.h>
#include <asm/cacheflush.h>
#include <asm/processor.h>
#include <asm/system.h>
#include <asm/stacktrace.h>
#include "setup.h"
static const char * const processor_modes[] = {
"UK00", "UK01", "UK02", "UK03", "UK04", "UK05", "UK06", "UK07",
"UK08", "UK09", "UK0A", "UK0B", "UK0C", "UK0D", "UK0E", "UK0F",
"USER", "REAL", "INTR", "PRIV", "UK14", "UK15", "UK16", "ABRT",
"UK18", "UK19", "UK1A", "EXTN", "UK1C", "UK1D", "UK1E", "SUSR"
};
/*
* The idle thread, has rather strange semantics for calling pm_idle,
* but this is what x86 does and we need to do the same, so that
* things like cpuidle get called in the same way.
*/
void cpu_idle(void)
{
/* endless idle loop with no priority at all */
while (1) {
tick_nohz_stop_sched_tick(1);
while (!need_resched()) {
local_irq_disable();
stop_critical_timings();
cpu_do_idle();
local_irq_enable();
start_critical_timings();
}
tick_nohz_restart_sched_tick();
preempt_enable_no_resched();
schedule();
preempt_disable();
}
}
static char reboot_mode = 'h';
int __init reboot_setup(char *str)
{
reboot_mode = str[0];
return 1;
}
__setup("reboot=", reboot_setup);
void machine_halt(void)
{
gpio_set_value(GPO_SOFT_OFF, 0);
}
/*
* Function pointers to optional machine specific functions
*/
void (*pm_power_off)(void) = NULL;
void machine_power_off(void)
{
if (pm_power_off)
pm_power_off();
machine_halt();
}
void machine_restart(char *cmd)
{
/* Disable interrupts first */
local_irq_disable();
/*
* Tell the mm system that we are going to reboot -
* we may need it to insert some 1:1 mappings so that
* soft boot works.
*/
setup_mm_for_reboot(reboot_mode);
/* Clean and invalidate caches */
flush_cache_all();
/* Turn off caching */
cpu_proc_fin();
/* Push out any further dirty data, and ensure cache is empty */
flush_cache_all();
/*
* Now handle reboot code.
*/
if (reboot_mode == 's') {
/* Jump into ROM at address 0xffff0000 */
cpu_reset(VECTORS_BASE);
} else {
PM_PLLSYSCFG = 0x00002001; /* cpu clk = 250M */
PM_PLLDDRCFG = 0x00100800; /* ddr clk = 44M */
PM_PLLVGACFG = 0x00002001; /* vga clk = 250M */
/* Use on-chip reset capability */
/* following instructions must be in one icache line */
__asm__ __volatile__(
" .align 5\n\t"
" stw %1, [%0]\n\t"
"201: ldw r0, [%0]\n\t"
" cmpsub.a r0, #0\n\t"
" bne 201b\n\t"
" stw %3, [%2]\n\t"
" nop; nop; nop\n\t"
/* prefetch 3 instructions at most */
:
: "r" ((unsigned long)&PM_PMCR),
"r" (PM_PMCR_CFBSYS | PM_PMCR_CFBDDR
| PM_PMCR_CFBVGA),
"r" ((unsigned long)&RESETC_SWRR),
"r" (RESETC_SWRR_SRB)
: "r0", "memory");
}
/*
* Whoops - the architecture was unable to reboot.
* Tell the user!
*/
mdelay(1000);
printk(KERN_EMERG "Reboot failed -- System halted\n");
do { } while (1);
}
void __show_regs(struct pt_regs *regs)
{
unsigned long flags;
char buf[64];
printk(KERN_DEFAULT "CPU: %d %s (%s %.*s)\n",
raw_smp_processor_id(), print_tainted(),
init_utsname()->release,
(int)strcspn(init_utsname()->version, " "),
init_utsname()->version);
print_symbol("PC is at %s\n", instruction_pointer(regs));
print_symbol("LR is at %s\n", regs->UCreg_lr);
printk(KERN_DEFAULT "pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
"sp : %08lx ip : %08lx fp : %08lx\n",
regs->UCreg_pc, regs->UCreg_lr, regs->UCreg_asr,
regs->UCreg_sp, regs->UCreg_ip, regs->UCreg_fp);
printk(KERN_DEFAULT "r26: %08lx r25: %08lx r24: %08lx\n",
regs->UCreg_26, regs->UCreg_25,
regs->UCreg_24);
printk(KERN_DEFAULT "r23: %08lx r22: %08lx r21: %08lx r20: %08lx\n",
regs->UCreg_23, regs->UCreg_22,
regs->UCreg_21, regs->UCreg_20);
printk(KERN_DEFAULT "r19: %08lx r18: %08lx r17: %08lx r16: %08lx\n",
regs->UCreg_19, regs->UCreg_18,
regs->UCreg_17, regs->UCreg_16);
printk(KERN_DEFAULT "r15: %08lx r14: %08lx r13: %08lx r12: %08lx\n",
regs->UCreg_15, regs->UCreg_14,
regs->UCreg_13, regs->UCreg_12);
printk(KERN_DEFAULT "r11: %08lx r10: %08lx r9 : %08lx r8 : %08lx\n",
regs->UCreg_11, regs->UCreg_10,
regs->UCreg_09, regs->UCreg_08);
printk(KERN_DEFAULT "r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
regs->UCreg_07, regs->UCreg_06,
regs->UCreg_05, regs->UCreg_04);
printk(KERN_DEFAULT "r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
regs->UCreg_03, regs->UCreg_02,
regs->UCreg_01, regs->UCreg_00);
flags = regs->UCreg_asr;
buf[0] = flags & PSR_S_BIT ? 'S' : 's';
buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
buf[4] = '\0';
printk(KERN_DEFAULT "Flags: %s INTR o%s REAL o%s Mode %s Segment %s\n",
buf, interrupts_enabled(regs) ? "n" : "ff",
fast_interrupts_enabled(regs) ? "n" : "ff",
processor_modes[processor_mode(regs)],
segment_eq(get_fs(), get_ds()) ? "kernel" : "user");
{
unsigned int ctrl;
buf[0] = '\0';
{
unsigned int transbase;
asm("movc %0, p0.c2, #0\n"
: "=r" (transbase));
snprintf(buf, sizeof(buf), " Table: %08x", transbase);
}
asm("movc %0, p0.c1, #0\n" : "=r" (ctrl));
printk(KERN_DEFAULT "Control: %08x%s\n", ctrl, buf);
}
}
void show_regs(struct pt_regs *regs)
{
printk(KERN_DEFAULT "\n");
printk(KERN_DEFAULT "Pid: %d, comm: %20s\n",
task_pid_nr(current), current->comm);
__show_regs(regs);
__backtrace();
}
/*
* Free current thread data structures etc..
*/
void exit_thread(void)
{
}
void flush_thread(void)
{
struct thread_info *thread = current_thread_info();
struct task_struct *tsk = current;
memset(thread->used_cp, 0, sizeof(thread->used_cp));
memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
#ifdef CONFIG_UNICORE_FPU_F64
memset(&thread->fpstate, 0, sizeof(struct fp_state));
#endif
}
void release_thread(struct task_struct *dead_task)
{
}
asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
int
copy_thread(unsigned long clone_flags, unsigned long stack_start,
unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
{
struct thread_info *thread = task_thread_info(p);
struct pt_regs *childregs = task_pt_regs(p);
*childregs = *regs;
childregs->UCreg_00 = 0;
childregs->UCreg_sp = stack_start;
memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
thread->cpu_context.sp = (unsigned long)childregs;
thread->cpu_context.pc = (unsigned long)ret_from_fork;
if (clone_flags & CLONE_SETTLS)
childregs->UCreg_16 = regs->UCreg_03;
return 0;
}
/*
* Fill in the task's elfregs structure for a core dump.
*/
int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
{
elf_core_copy_regs(elfregs, task_pt_regs(t));
return 1;
}
/*
* fill in the fpe structure for a core dump...
*/
int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fp)
{
struct thread_info *thread = current_thread_info();
int used_math = thread->used_cp[1] | thread->used_cp[2];
#ifdef CONFIG_UNICORE_FPU_F64
if (used_math)
memcpy(fp, &thread->fpstate, sizeof(*fp));
#endif
return used_math != 0;
}
EXPORT_SYMBOL(dump_fpu);
/*
* Shuffle the argument into the correct register before calling the
* thread function. r1 is the thread argument, r2 is the pointer to
* the thread function, and r3 points to the exit function.
*/
asm(".pushsection .text\n"
" .align\n"
" .type kernel_thread_helper, #function\n"
"kernel_thread_helper:\n"
" mov.a asr, r7\n"
" mov r0, r4\n"
" mov lr, r6\n"
" mov pc, r5\n"
" .size kernel_thread_helper, . - kernel_thread_helper\n"
" .popsection");
/*
* Create a kernel thread.
*/
pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
{
struct pt_regs regs;
memset(&regs, 0, sizeof(regs));
regs.UCreg_04 = (unsigned long)arg;
regs.UCreg_05 = (unsigned long)fn;
regs.UCreg_06 = (unsigned long)do_exit;
regs.UCreg_07 = PRIV_MODE;
regs.UCreg_pc = (unsigned long)kernel_thread_helper;
regs.UCreg_asr = regs.UCreg_07 | PSR_I_BIT;
return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
}
EXPORT_SYMBOL(kernel_thread);
unsigned long get_wchan(struct task_struct *p)
{
struct stackframe frame;
int count = 0;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
frame.fp = thread_saved_fp(p);
frame.sp = thread_saved_sp(p);
frame.lr = 0; /* recovered from the stack */
frame.pc = thread_saved_pc(p);
do {
int ret = unwind_frame(&frame);
if (ret < 0)
return 0;
if (!in_sched_functions(frame.pc))
return frame.pc;
} while ((count++) < 16);
return 0;
}
unsigned long arch_randomize_brk(struct mm_struct *mm)
{
unsigned long range_end = mm->brk + 0x02000000;
return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
}
/*
* The vectors page is always readable from user space for the
* atomic helpers and the signal restart code. Let's declare a mapping
* for it so it is visible through ptrace and /proc/<pid>/mem.
*/
int vectors_user_mapping(void)
{
struct mm_struct *mm = current->mm;
return install_special_mapping(mm, 0xffff0000, PAGE_SIZE,
VM_READ | VM_EXEC |
VM_MAYREAD | VM_MAYEXEC |
VM_ALWAYSDUMP | VM_RESERVED,
NULL);
}
const char *arch_vma_name(struct vm_area_struct *vma)
{
return (vma->vm_start == 0xffff0000) ? "[vectors]" : NULL;
}

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/*
* linux/arch/unicore32/kernel/stacktrace.c
*
* Code specific to PKUnity SoC and UniCore ISA
*
* Copyright (C) 2001-2010 GUAN Xue-tao
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/stacktrace.h>
#include <asm/stacktrace.h>
#if defined(CONFIG_FRAME_POINTER)
/*
* Unwind the current stack frame and store the new register values in the
* structure passed as argument. Unwinding is equivalent to a function return,
* hence the new PC value rather than LR should be used for backtrace.
*
* With framepointer enabled, a simple function prologue looks like this:
* mov ip, sp
* stmdb sp!, {fp, ip, lr, pc}
* sub fp, ip, #4
*
* A simple function epilogue looks like this:
* ldm sp, {fp, sp, pc}
*
* Note that with framepointer enabled, even the leaf functions have the same
* prologue and epilogue, therefore we can ignore the LR value in this case.
*/
int notrace unwind_frame(struct stackframe *frame)
{
unsigned long high, low;
unsigned long fp = frame->fp;
/* only go to a higher address on the stack */
low = frame->sp;
high = ALIGN(low, THREAD_SIZE);
/* check current frame pointer is within bounds */
if (fp < (low + 12) || fp + 4 >= high)
return -EINVAL;
/* restore the registers from the stack frame */
frame->fp = *(unsigned long *)(fp - 12);
frame->sp = *(unsigned long *)(fp - 8);
frame->pc = *(unsigned long *)(fp - 4);
return 0;
}
#endif
void notrace walk_stackframe(struct stackframe *frame,
int (*fn)(struct stackframe *, void *), void *data)
{
while (1) {
int ret;
if (fn(frame, data))
break;
ret = unwind_frame(frame);
if (ret < 0)
break;
}
}
EXPORT_SYMBOL(walk_stackframe);
#ifdef CONFIG_STACKTRACE
struct stack_trace_data {
struct stack_trace *trace;
unsigned int no_sched_functions;
unsigned int skip;
};
static int save_trace(struct stackframe *frame, void *d)
{
struct stack_trace_data *data = d;
struct stack_trace *trace = data->trace;
unsigned long addr = frame->pc;
if (data->no_sched_functions && in_sched_functions(addr))
return 0;
if (data->skip) {
data->skip--;
return 0;
}
trace->entries[trace->nr_entries++] = addr;
return trace->nr_entries >= trace->max_entries;
}
void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
{
struct stack_trace_data data;
struct stackframe frame;
data.trace = trace;
data.skip = trace->skip;
if (tsk != current) {
data.no_sched_functions = 1;
frame.fp = thread_saved_fp(tsk);
frame.sp = thread_saved_sp(tsk);
frame.lr = 0; /* recovered from the stack */
frame.pc = thread_saved_pc(tsk);
} else {
register unsigned long current_sp asm("sp");
data.no_sched_functions = 0;
frame.fp = (unsigned long)__builtin_frame_address(0);
frame.sp = current_sp;
frame.lr = (unsigned long)__builtin_return_address(0);
frame.pc = (unsigned long)save_stack_trace_tsk;
}
walk_stackframe(&frame, save_trace, &data);
if (trace->nr_entries < trace->max_entries)
trace->entries[trace->nr_entries++] = ULONG_MAX;
}
void save_stack_trace(struct stack_trace *trace)
{
save_stack_trace_tsk(current, trace);
}
EXPORT_SYMBOL_GPL(save_stack_trace);
#endif

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/*
* linux/arch/unicore32/lib/backtrace.S
*
* Code specific to PKUnity SoC and UniCore ISA
*
* Copyright (C) 2001-2010 GUAN Xue-tao
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
.text
@ fp is 0 or stack frame
#define frame v4
#define sv_fp v5
#define sv_pc v6
#define offset v8
ENTRY(__backtrace)
mov r0, fp
ENTRY(c_backtrace)
#if !defined(CONFIG_FRAME_POINTER) || !defined(CONFIG_PRINTK)
mov pc, lr
ENDPROC(__backtrace)
ENDPROC(c_backtrace)
#else
stm.w (v4 - v8, lr), [sp-] @ Save an extra register
@ so we have a location...
mov.a frame, r0 @ if frame pointer is zero
beq no_frame @ we have no stack frames
1: stm.w (pc), [sp-] @ calculate offset of PC stored
ldw.w r0, [sp]+, #4 @ by stmfd for this CPU
adr r1, 1b
sub offset, r0, r1
/*
* Stack frame layout:
* optionally saved caller registers (r4 - r10)
* saved fp
* saved sp
* saved lr
* frame => saved pc
* optionally saved arguments (r0 - r3)
* saved sp => <next word>
*
* Functions start with the following code sequence:
* mov ip, sp
* stm.w (r0 - r3), [sp-] (optional)
* corrected pc => stm.w sp, (..., fp, ip, lr, pc)
*/
for_each_frame:
1001: ldw sv_pc, [frame+], #0 @ get saved pc
1002: ldw sv_fp, [frame+], #-12 @ get saved fp
sub sv_pc, sv_pc, offset @ Correct PC for prefetching
1003: ldw r2, [sv_pc+], #-4 @ if stmfd sp, {args} exists,
ldw r3, .Ldsi+4 @ adjust saved 'pc' back one
cxor.a r3, r2 >> #14 @ instruction
beq 201f
sub r0, sv_pc, #4 @ allow for mov
b 202f
201:
sub r0, sv_pc, #8 @ allow for mov + stmia
202:
ldw r1, [frame+], #-4 @ get saved lr
mov r2, frame
b.l dump_backtrace_entry
ldw r1, [sv_pc+], #-4 @ if stmfd sp, {args} exists,
ldw r3, .Ldsi+4
cxor.a r3, r1 >> #14
bne 1004f
ldw r0, [frame+], #-8 @ get sp
sub r0, r0, #4 @ point at the last arg
b.l .Ldumpstm @ dump saved registers
1004: ldw r1, [sv_pc+], #0 @ if stmfd {, fp, ip, lr, pc}
ldw r3, .Ldsi @ instruction exists,
cxor.a r3, r1 >> #14
bne 201f
sub r0, frame, #16
b.l .Ldumpstm @ dump saved registers
201:
cxor.a sv_fp, #0 @ zero saved fp means
beq no_frame @ no further frames
csub.a sv_fp, frame @ next frame must be
mov frame, sv_fp @ above the current frame
bua for_each_frame
1006: adr r0, .Lbad
mov r1, frame
b.l printk
no_frame: ldm.w (v4 - v8, pc), [sp]+
ENDPROC(__backtrace)
ENDPROC(c_backtrace)
.pushsection __ex_table,"a"
.align 3
.long 1001b, 1006b
.long 1002b, 1006b
.long 1003b, 1006b
.long 1004b, 1006b
.popsection
#define instr v4
#define reg v5
#define stack v6
.Ldumpstm: stm.w (instr, reg, stack, v7, lr), [sp-]
mov stack, r0
mov instr, r1
mov reg, #14
mov v7, #0
1: mov r3, #1
csub.a reg, #8
bne 201f
sub reg, reg, #3
201:
cand.a instr, r3 << reg
beq 2f
add v7, v7, #1
cxor.a v7, #6
cmoveq v7, #1
cmoveq r1, #'\n'
cmovne r1, #' '
ldw.w r3, [stack]+, #-4
mov r2, reg
csub.a r2, #8
bsl 201f
sub r2, r2, #3
201:
cand.a instr, #0x40 @ if H is 1, high 16 regs
beq 201f
add r2, r2, #0x10 @ so r2 need add 16
201:
adr r0, .Lfp
b.l printk
2: sub.a reg, reg, #1
bns 1b
cxor.a v7, #0
beq 201f
adr r0, .Lcr
b.l printk
201: ldm.w (instr, reg, stack, v7, pc), [sp]+
.Lfp: .asciz "%cr%d:%08x"
.Lcr: .asciz "\n"
.Lbad: .asciz "Backtrace aborted due to bad frame pointer <%p>\n"
.align
.Ldsi: .word 0x92eec000 >> 14 @ stm.w sp, (... fp, ip, lr, pc)
.word 0x92e10000 >> 14 @ stm.w sp, ()
#endif