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author | GuanXuetao <gxt@mprc.pku.edu.cn> | 2011-01-15 10:15:45 (GMT) |
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committer | GuanXuetao <gxt@mprc.pku.edu.cn> | 2011-03-17 01:19:06 (GMT) |
commit | 141c943fd4b323bae2b47f67743dba96134afb1f (patch) | |
tree | 0482b81478e8b40ce06eeebe7f4ed88aafc593c0 /arch/unicore32/kernel/traps.c | |
parent | 79725df5786d2fa48f582b116ea1d74193cc96ca (diff) | |
download | linux-fsl-qoriq-141c943fd4b323bae2b47f67743dba96134afb1f.tar.xz |
unicore32 core architecture: low level entry and setup codes
This patch implements low level entry and setup codes.
Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/unicore32/kernel/traps.c')
-rw-r--r-- | arch/unicore32/kernel/traps.c | 333 |
1 files changed, 333 insertions, 0 deletions
diff --git a/arch/unicore32/kernel/traps.c b/arch/unicore32/kernel/traps.c new file mode 100644 index 0000000..25abbb1 --- /dev/null +++ b/arch/unicore32/kernel/traps.c @@ -0,0 +1,333 @@ +/* + * linux/arch/unicore32/kernel/traps.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. + * + * 'traps.c' handles hardware exceptions after we have saved some state. + * Mostly a debugging aid, but will probably kill the offending process. + */ +#include <linux/module.h> +#include <linux/signal.h> +#include <linux/spinlock.h> +#include <linux/personality.h> +#include <linux/kallsyms.h> +#include <linux/kdebug.h> +#include <linux/uaccess.h> +#include <linux/delay.h> +#include <linux/hardirq.h> +#include <linux/init.h> +#include <linux/uaccess.h> +#include <linux/atomic.h> +#include <linux/unistd.h> + +#include <asm/cacheflush.h> +#include <asm/system.h> +#include <asm/traps.h> + +#include "setup.h" + +static void dump_mem(const char *, const char *, unsigned long, unsigned long); + +void dump_backtrace_entry(unsigned long where, + unsigned long from, unsigned long frame) +{ +#ifdef CONFIG_KALLSYMS + printk(KERN_DEFAULT "[<%08lx>] (%pS) from [<%08lx>] (%pS)\n", + where, (void *)where, from, (void *)from); +#else + printk(KERN_DEFAULT "Function entered at [<%08lx>] from [<%08lx>]\n", + where, from); +#endif +} + +/* + * Stack pointers should always be within the kernels view of + * physical memory. If it is not there, then we can't dump + * out any information relating to the stack. + */ +static int verify_stack(unsigned long sp) +{ + if (sp < PAGE_OFFSET || + (sp > (unsigned long)high_memory && high_memory != NULL)) + return -EFAULT; + + return 0; +} + +/* + * Dump out the contents of some memory nicely... + */ +static void dump_mem(const char *lvl, const char *str, unsigned long bottom, + unsigned long top) +{ + unsigned long first; + mm_segment_t fs; + int i; + + /* + * We need to switch to kernel mode so that we can use __get_user + * to safely read from kernel space. Note that we now dump the + * code first, just in case the backtrace kills us. + */ + fs = get_fs(); + set_fs(KERNEL_DS); + + printk(KERN_DEFAULT "%s%s(0x%08lx to 0x%08lx)\n", + lvl, str, bottom, top); + + for (first = bottom & ~31; first < top; first += 32) { + unsigned long p; + char str[sizeof(" 12345678") * 8 + 1]; + + memset(str, ' ', sizeof(str)); + str[sizeof(str) - 1] = '\0'; + + for (p = first, i = 0; i < 8 && p < top; i++, p += 4) { + if (p >= bottom && p < top) { + unsigned long val; + if (__get_user(val, (unsigned long *)p) == 0) + sprintf(str + i * 9, " %08lx", val); + else + sprintf(str + i * 9, " ????????"); + } + } + printk(KERN_DEFAULT "%s%04lx:%s\n", lvl, first & 0xffff, str); + } + + set_fs(fs); +} + +static void dump_instr(const char *lvl, struct pt_regs *regs) +{ + unsigned long addr = instruction_pointer(regs); + const int width = 8; + mm_segment_t fs; + char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str; + int i; + + /* + * We need to switch to kernel mode so that we can use __get_user + * to safely read from kernel space. Note that we now dump the + * code first, just in case the backtrace kills us. + */ + fs = get_fs(); + set_fs(KERNEL_DS); + + for (i = -4; i < 1; i++) { + unsigned int val, bad; + + bad = __get_user(val, &((u32 *)addr)[i]); + + if (!bad) + p += sprintf(p, i == 0 ? "(%0*x) " : "%0*x ", + width, val); + else { + p += sprintf(p, "bad PC value"); + break; + } + } + printk(KERN_DEFAULT "%sCode: %s\n", lvl, str); + + set_fs(fs); +} + +static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) +{ + unsigned int fp, mode; + int ok = 1; + + printk(KERN_DEFAULT "Backtrace: "); + + if (!tsk) + tsk = current; + + if (regs) { + fp = regs->UCreg_fp; + mode = processor_mode(regs); + } else if (tsk != current) { + fp = thread_saved_fp(tsk); + mode = 0x10; + } else { + asm("mov %0, fp" : "=r" (fp) : : "cc"); + mode = 0x10; + } + + if (!fp) { + printk("no frame pointer"); + ok = 0; + } else if (verify_stack(fp)) { + printk("invalid frame pointer 0x%08x", fp); + ok = 0; + } else if (fp < (unsigned long)end_of_stack(tsk)) + printk("frame pointer underflow"); + printk("\n"); + + if (ok) + c_backtrace(fp, mode); +} + +void dump_stack(void) +{ + dump_backtrace(NULL, NULL); +} +EXPORT_SYMBOL(dump_stack); + +void show_stack(struct task_struct *tsk, unsigned long *sp) +{ + dump_backtrace(NULL, tsk); + barrier(); +} + +static int __die(const char *str, int err, struct thread_info *thread, + struct pt_regs *regs) +{ + struct task_struct *tsk = thread->task; + static int die_counter; + int ret; + + printk(KERN_EMERG "Internal error: %s: %x [#%d]\n", + str, err, ++die_counter); + sysfs_printk_last_file(); + + /* trap and error numbers are mostly meaningless on UniCore */ + ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, \ + SIGSEGV); + if (ret == NOTIFY_STOP) + return ret; + + print_modules(); + __show_regs(regs); + printk(KERN_EMERG "Process %.*s (pid: %d, stack limit = 0x%p)\n", + TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), thread + 1); + + if (!user_mode(regs) || in_interrupt()) { + dump_mem(KERN_EMERG, "Stack: ", regs->UCreg_sp, + THREAD_SIZE + (unsigned long)task_stack_page(tsk)); + dump_backtrace(regs, tsk); + dump_instr(KERN_EMERG, regs); + } + + return ret; +} + +DEFINE_SPINLOCK(die_lock); + +/* + * This function is protected against re-entrancy. + */ +void die(const char *str, struct pt_regs *regs, int err) +{ + struct thread_info *thread = current_thread_info(); + int ret; + + oops_enter(); + + spin_lock_irq(&die_lock); + console_verbose(); + bust_spinlocks(1); + ret = __die(str, err, thread, regs); + + bust_spinlocks(0); + add_taint(TAINT_DIE); + spin_unlock_irq(&die_lock); + oops_exit(); + + if (in_interrupt()) + panic("Fatal exception in interrupt"); + if (panic_on_oops) + panic("Fatal exception"); + if (ret != NOTIFY_STOP) + do_exit(SIGSEGV); +} + +void uc32_notify_die(const char *str, struct pt_regs *regs, + struct siginfo *info, unsigned long err, unsigned long trap) +{ + if (user_mode(regs)) { + current->thread.error_code = err; + current->thread.trap_no = trap; + + force_sig_info(info->si_signo, info, current); + } else + die(str, regs, err); +} + +/* + * bad_mode handles the impossible case in the vectors. If you see one of + * these, then it's extremely serious, and could mean you have buggy hardware. + * It never returns, and never tries to sync. We hope that we can at least + * dump out some state information... + */ +asmlinkage void bad_mode(struct pt_regs *regs, unsigned int reason) +{ + console_verbose(); + + printk(KERN_CRIT "Bad mode detected with reason 0x%x\n", reason); + + die("Oops - bad mode", regs, 0); + local_irq_disable(); + panic("bad mode"); +} + +void __pte_error(const char *file, int line, unsigned long val) +{ + printk(KERN_DEFAULT "%s:%d: bad pte %08lx.\n", file, line, val); +} + +void __pmd_error(const char *file, int line, unsigned long val) +{ + printk(KERN_DEFAULT "%s:%d: bad pmd %08lx.\n", file, line, val); +} + +void __pgd_error(const char *file, int line, unsigned long val) +{ + printk(KERN_DEFAULT "%s:%d: bad pgd %08lx.\n", file, line, val); +} + +asmlinkage void __div0(void) +{ + printk(KERN_DEFAULT "Division by zero in kernel.\n"); + dump_stack(); +} +EXPORT_SYMBOL(__div0); + +void abort(void) +{ + BUG(); + + /* if that doesn't kill us, halt */ + panic("Oops failed to kill thread"); +} +EXPORT_SYMBOL(abort); + +void __init trap_init(void) +{ + return; +} + +void __init early_trap_init(void) +{ + unsigned long vectors = VECTORS_BASE; + + /* + * Copy the vectors, stubs (in entry-unicore.S) + * into the vector page, mapped at 0xffff0000, and ensure these + * are visible to the instruction stream. + */ + memcpy((void *)vectors, + __vectors_start, + __vectors_end - __vectors_start); + memcpy((void *)vectors + 0x200, + __stubs_start, + __stubs_end - __stubs_start); + + early_signal_init(); + + flush_icache_range(vectors, vectors + PAGE_SIZE); +} |