+++ /dev/null
-/*
- * arch/ubicom32/kernel/traps.c
- * Ubicom32 architecture trap handling support.
- *
- * (C) Copyright 2009, Ubicom, Inc.
- *
- * This file is part of the Ubicom32 Linux Kernel Port.
- *
- * The Ubicom32 Linux Kernel Port is free software: you can redistribute
- * it and/or modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation, either version 2 of the
- * License, or (at your option) any later version.
- *
- * The Ubicom32 Linux Kernel Port is distributed in the hope that it
- * will be useful, but WITHOUT ANY WARRANTY; without even the implied
- * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
- * the GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with the Ubicom32 Linux Kernel Port. If not,
- * see <http://www.gnu.org/licenses/>.
- *
- * Ubicom32 implementation derived from (with many thanks):
- * arch/m68knommu
- * arch/blackfin
- * arch/parisc
- */
-
-/*
- * Sets up all exception vectors
- */
-#include <linux/sched.h>
-#include <linux/signal.h>
-#include <linux/kernel.h>
-#include <linux/mm.h>
-#include <linux/module.h>
-#include <linux/types.h>
-#include <linux/a.out.h>
-#include <linux/user.h>
-#include <linux/string.h>
-#include <linux/linkage.h>
-#include <linux/init.h>
-#include <linux/ptrace.h>
-#include <linux/kallsyms.h>
-#include <linux/compiler.h>
-#include <linux/stacktrace.h>
-#include <linux/personality.h>
-
-#include <asm/uaccess.h>
-#include <asm/stacktrace.h>
-#include <asm/devtree.h>
-#include <asm/setup.h>
-#include <asm/fpu.h>
-#include <asm/system.h>
-#include <asm/traps.h>
-#include <asm/pgtable.h>
-#include <asm/processor.h>
-#include <asm/machdep.h>
-#include <asm/siginfo.h>
-#include <asm/ip5000.h>
-#include <asm/thread.h>
-
-#define TRAP_MAX_STACK_DEPTH 20
-
-/*
- * These symbols are filled in by the linker.
- */
-extern unsigned long _stext;
-extern unsigned long _etext;
-
-extern unsigned long __ocm_text_run_begin;
-extern unsigned long __data_begin;
-
-extern void show_vmas(struct task_struct *task);
-
-const char *trap_cause_strings[] = {
- /*0*/ "inst address decode error",
- /*1*/ "inst sync error",
- /*2*/ "inst illegal",
- /*3*/ "src1 address decode error",
- /*4*/ "dst address decode error",
- /*5*/ "src1 alignment error",
- /*6*/ "dst alignment error",
- /*7*/ "src1 sync error",
- /*8*/ "dst sync error",
- /*9*/ "DCAPT error",
- /*10*/ "inst range error",
- /*11*/ "src1 range error",
- /*12*/ "dst range error",
-};
-
-/*
- * The device tree trap node definition.
- */
-struct trapnode {
- struct devtree_node dn;
- unsigned int intthread;
-};
-
-static struct trapnode *tn;;
-
-/*
- * trap_interrupt_handler()
- * Software Interrupt to ensure that a trap is serviced.
- */
-static irqreturn_t trap_interrupt_handler(int irq, void *dummy)
-{
- /* Do Nothing */
- return IRQ_HANDLED;
-}
-
-/*
- * Data used by setup_irq for the timer.
- */
-static struct irqaction trap_irq = {
- .name = "trap",
- .flags = IRQF_DISABLED,
- .handler = trap_interrupt_handler,
-};
-
-/*
- * trap_cause_to_str()
- * Convert a trap_cause into a series of printk
- */
-static void trap_cause_to_str(long status)
-{
- int bit;
-
- if ((status & ((1 << TRAP_CAUSE_TOTAL) - 1)) == 0) {
- printk(KERN_NOTICE "decode: UNKNOWN CAUSES\n");
- return;
- }
-
- for (bit = 0; bit < TRAP_CAUSE_TOTAL; bit++) {
- if (status & (1 << bit)) {
- printk(KERN_NOTICE "\tdecode: %08x %s\n",
- 1 << bit, trap_cause_strings[bit]);
- }
- }
-}
-
-/*
- * trap_print_information()
- * Print the cause of the trap and additional info.
- */
-static void trap_print_information(const char *str, struct pt_regs *regs)
-{
- printk(KERN_WARNING "\n");
-
- if (current) {
- printk(KERN_WARNING "Process %s (pid: %d)\n",
- current->comm, current->pid);
- }
-
- if (current && current->mm) {
- printk(KERN_NOTICE "text = 0x%p-0x%p data = 0x%p-0x%p\n"
- KERN_NOTICE "bss = 0x%p-0x%p user-stack = 0x%p\n"
- KERN_NOTICE "\n",
- (void *)current->mm->start_code,
- (void *)current->mm->end_code,
- (void *)current->mm->start_data,
- (void *)current->mm->end_data,
- (void *)current->mm->end_data,
- (void *)current->mm->brk,
- (void *)current->mm->start_stack);
- }
-
- printk(KERN_WARNING "%s: Causes: 0x%08x\n", str,
- (unsigned int)regs->trap_cause);
- trap_cause_to_str(regs->trap_cause);
- show_regs(regs);
- show_stack(NULL, (unsigned long *)regs->an[7]);
- printk(KERN_NOTICE "--- End Trap --- \n");
-}
-
-/*
- * dump_stack()
- * Dump the stack of the current task.
- */
-void dump_stack(void)
-{
- show_stack(NULL, NULL);
-}
-EXPORT_SYMBOL(dump_stack);
-
-/*
- * show_stack()
- * Print out information from the current stack.
- */
-void show_stack(struct task_struct *task, unsigned long *sp)
-{
- /*
- * Allocate just enough entries on the stack.
- */
- unsigned int calls[TRAP_MAX_STACK_DEPTH];
- unsigned long code_start;
- unsigned long code_end;
- unsigned long ocm_code_start = (unsigned long)&__ocm_text_run_begin;
- unsigned long ocm_code_end = (unsigned long)&__data_begin;
- unsigned long stack_end = (unsigned long)(current->stack + THREAD_SIZE - 8);
- unsigned long stack = (unsigned long)sp;
- int kernel_stack = 1;
-
- processor_dram(&code_start, &code_end);
-
- /*
- * Which task are we talking about.
- */
- if (!task) {
- task = current;
- }
-
- /*
- * Find the stack for the task if one was not specified. Otherwise
- * use the specified stack.
- */
- if (!stack) {
- if (task != current) {
- stack = task->thread.sp;
- stack_end = (unsigned long)task->stack + THREAD_SIZE - 8;
- } else {
- asm volatile (
- "move.4 %0, SP \n\t"
- : "=r" (stack)
- );
- }
- }
-
- printk(KERN_NOTICE "Starting backtrace: PID %d '%s'\n",
- task->pid, task->comm);
-
- /*
- * We do 2 passes the first pass is Kernel stack is the second
- * User stack.
- */
- while (kernel_stack) {
- unsigned long *handle;
- unsigned int i, idx = 0;
- struct pt_regs *pt = task_pt_regs(task);
-
- /*
- * If the task is in user mode, reset the start
- * and end values for text.
- */
- if (__user_mode(stack)) {
- if (!(task->personality & FDPIC_FUNCPTRS)) {
- printk(KERN_NOTICE " User Stack:\n");
- code_start = task->mm->start_code;
- code_end = task->mm->end_code;
- } else {
- printk(KERN_NOTICE " User Stack (fdpic):\n");
- show_vmas(task);
- }
- stack_end = task->mm->start_stack;
- ocm_code_end = ocm_code_start = 0;
- kernel_stack = 0;
- } else {
- printk(KERN_NOTICE " Kernel Stack:\n");
- }
-
- /*
- * Collect the stack back trace information.
- */
- printk(" code[0x%lx-0x%lx]", code_start, code_end);
- if (ocm_code_start) {
- printk(" ocm_code[0x%lx-0x%lx]",
- ocm_code_start, ocm_code_end);
- }
- printk("\n stack[0x%lx-0x%lx]\n", stack, stack_end);
-
- handle = (unsigned long*)stack;
- while (idx < TRAP_MAX_STACK_DEPTH) {
- calls[idx] = stacktrace_iterate(&handle,
- code_start, code_end,
- ocm_code_start, ocm_code_end,
- (unsigned long)stack, stack_end);
- if (calls[idx] == 0) {
- break;
- }
- idx++;
- }
-
- /*
- * Now print out the data.
- */
- printk(KERN_NOTICE " CALL && CALLI on stack:");
- for (i = 0; i < idx; i++) {
- printk("%s0x%x, ", (i & 0x3) == 0 ? "\n " : "",
- calls[i]);
- }
- printk(idx == TRAP_MAX_STACK_DEPTH ? "...\n" : "\n");
-
- /*
- * If we are doing user stack we are done
- */
- if (!kernel_stack) {
- break;
- }
-
- /*
- * Does this kernel stack have a mm (i.e. is it user)
- */
- if (!task->mm) {
- printk("No mm for userspace stack.\n");
- break;
- }
- /*
- * Get the user-mode stack (if any)
- */
- stack = pt->an[7];
- printk(KERN_NOTICE "Userspace stack at 0x%lx frame type %d\n",
- stack, (int)pt->frame_type);
- if (!__user_mode(stack)) {
- break;
- }
- }
-}
-
-/*
- * die_if_kernel()
- * Determine if we are in kernel mode and if so print stuff out and die.
- */
-void die_if_kernel(char *str, struct pt_regs *regs, long trap_cause)
-{
- unsigned int s3value;
-
- if (user_mode(regs)) {
- return;
- }
-
- console_verbose();
- trap_print_information(str, regs);
-
- /*
- * If the debugger is attached via the hardware mailbox protocol,
- * go into an infinite loop and the debugger will figure things out.
- */
- asm volatile (
- "move.4 %0, scratchpad3"
- : "=r" (s3value)
- );
- if (s3value) {
- asm volatile("1: jmpt.t 1b");
- }
-
- /*
- * Set the debug taint value.
- */
- add_taint(TAINT_DIE);
- do_exit(SIGSEGV);
-}
-
-/*
- * trap_handler()
- * Handle traps.
- *
- * Traps are treated as interrupts and registered with the LDSR. When
- * the LDSR takes the interrupt, it will determine if a trap has occurred
- * and service the trap prior to servicing the interrupt.
- *
- * This function is directly called by the LDSR.
- */
-void trap_handler(int irq, struct pt_regs *regs)
-{
- int sig = SIGSEGV;
- siginfo_t info;
- unsigned int trap_cause = regs->trap_cause;
-
- BUG_ON(!irqs_disabled());
-
- /*
- * test if in kernel and die.
- */
- die_if_kernel("Kernel Trap", regs, trap_cause);
-
- /*
- * User process problem, setup a signal for this process
- */
- if ((trap_cause & (1 << TRAP_CAUSE_DST_RANGE_ERR)) ||
- (trap_cause & (1 << TRAP_CAUSE_SRC1_RANGE_ERR)) ||
- (trap_cause & (1 << TRAP_CAUSE_I_RANGE_ERR))) {
- sig = SIGSEGV;
- info.si_code = SEGV_MAPERR;
- } else if ((trap_cause & (1 << TRAP_CAUSE_DST_MISALIGNED)) ||
- (trap_cause & (1 << TRAP_CAUSE_SRC1_MISALIGNED))) {
- sig = SIGBUS;
- info.si_code = BUS_ADRALN;
- } else if ((trap_cause & (1 << TRAP_CAUSE_DST_DECODE_ERR)) ||
- (trap_cause & (1 << TRAP_CAUSE_SRC1_DECODE_ERR))) {
- sig = SIGILL;
- info.si_code = ILL_ILLOPN;
- } else if ((trap_cause & (1 << TRAP_CAUSE_ILLEGAL_INST))) {
- /*
- * Check for software break point and if found signal trap
- * not illegal instruction.
- */
- unsigned long instruction;
- if (between(regs->pc, KERNELSTART, memory_end) &&
- (regs->pc & 3) == 0 &&
- get_user(instruction, (unsigned long *)regs->pc) == 0) {
-
- /*
- * This used to be 0xaabbccdd but it turns out
- * that is now valid in ubicom32v4 isa so we
- * have switched to 0xfabbccdd
- */
- if ((instruction == 0xfabbccdd) ||
- (instruction == 0xaabbccdd)) {
- sig = SIGTRAP;
- info.si_code = TRAP_BRKPT;
- goto send_signal;
- }
- }
- sig = SIGILL;
- info.si_code = ILL_ILLOPC;
- } else if ((trap_cause & (1 << TRAP_CAUSE_I_DECODE_ERR))) {
- sig = SIGILL;
- info.si_code = ILL_ILLOPC;
- } else if ((trap_cause & (1 << TRAP_CAUSE_DCAPT))) {
- sig = SIGTRAP;
- info.si_code = TRAP_TRACE;
- }
-
- /*
- * Print a trap information block to the console, do not
- * print this above the case because we don't want it
- * printed for software break points.
- */
- trap_print_information("User Trap", regs);
-
-send_signal:
-
- force_sig_info(sig, &info, current);
-
- /*
- * Interrupts are disabled, re-enable them now.
- */
- if (!irqs_disabled()) {
- printk(KERN_EMERG "interrupts enabled on exit, irq=%d, regs=%p",
- irq, regs);
- BUG();
- }
-}
-
-/*
- * trap_init_interrupt()
- * We need a 2nd trap handling init that will occur after init_IRQ().
- */
-void __init trap_init_interrupt(void)
-{
- int err;
- unsigned char tirq;
- struct devtree_node *dn = (struct devtree_node *)tn;
-
- /*
- * Now setup the Software IRQ so that if a trap occurs the LDSR
- * is started. The irq is there just to "force" the LDSR to run.
- */
- if (!tn) {
- printk(KERN_WARNING "trap_init_interrupt skipped.\n");
- return;
- }
-
- err = devtree_irq(dn, NULL, &tirq);
- if (err) {
- printk(KERN_WARNING "error obtaining trap irq value: %d\n",
- err);
- return;
- }
-
- if (tirq == DEVTREE_IRQ_NONE) {
- printk(KERN_WARNING "trap irq not available: %d\n", tirq);
- return;
- }
-
- err = setup_irq(tirq, &trap_irq);
- if (err) {
- printk(KERN_WARNING "trap irq setup failed: %d\n", err);
- return;
- }
-
- /*
- * Let ultra know which thread is handling the traps and
- * what the interrupt to use is.
- */
- tn->intthread = ldsr_get_threadid();
-
- /*
- * Tell the LDSR about our IRQ so that it will unsuspend
- * if one occurs while waiting for the per thread lock.
- */
- ldsr_set_trap_irq(tirq);
-}
-
-/*
- * trap_init()
- * init trap handling
- *
- * Trap handling is done through the ldsr. Every time an interrupt
- * occurs, the LDSR looks for threads that are listed in the TRAP
- * register and forces a call to the trap handler.
- */
-void __init trap_init(void)
-{
- /*
- * If we do not have a trap node in the device tree, we leave the fault
- * handling to the underlying hardware.
- */
- tn = (struct trapnode *)devtree_find_node("traps");
- if (!tn) {
- printk(KERN_WARNING "traps are not handled by linux\n");
- return;
- }
-}
projects / openwrt.git / blobdiff