From 5a0015d62668e64c8b6e02e360fbbea121bfd5e6 Mon Sep 17 00:00:00 2001 From: Chris Zankel Date: Thu, 23 Jun 2005 22:01:16 -0700 Subject: [PATCH] xtensa: Architecture support for Tensilica Xtensa Part 3 The attached patches provides part 3 of an architecture implementation for the Tensilica Xtensa CPU series. Signed-off-by: Chris Zankel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/xtensa/kernel/traps.c | 498 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 498 insertions(+) create mode 100644 arch/xtensa/kernel/traps.c (limited to 'arch/xtensa/kernel/traps.c') diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c new file mode 100644 index 00000000000..804246e743b --- /dev/null +++ b/arch/xtensa/kernel/traps.c @@ -0,0 +1,498 @@ +/* + * arch/xtensa/kernel/traps.c + * + * Exception handling. + * + * Derived from code with the following copyrights: + * Copyright (C) 1994 - 1999 by Ralf Baechle + * Modified for R3000 by Paul M. Antoine, 1995, 1996 + * Complete output from die() by Ulf Carlsson, 1998 + * Copyright (C) 1999 Silicon Graphics, Inc. + * + * Essentially rewritten for the Xtensa architecture port. + * + * Copyright (C) 2001 - 2005 Tensilica Inc. + * + * Joe Taylor + * Chris Zankel + * Marc Gauthier + * Kevin Chea + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include + +#ifdef CONFIG_KGDB +extern int gdb_enter; +extern int return_from_debug_flag; +#endif + +/* + * Machine specific interrupt handlers + */ + +extern void kernel_exception(void); +extern void user_exception(void); + +extern void fast_syscall_kernel(void); +extern void fast_syscall_user(void); +extern void fast_alloca(void); +extern void fast_unaligned(void); +extern void fast_second_level_miss(void); +extern void fast_store_prohibited(void); +extern void fast_coprocessor(void); + +extern void do_illegal_instruction (struct pt_regs*); +extern void do_interrupt (struct pt_regs*); +extern void do_unaligned_user (struct pt_regs*); +extern void do_multihit (struct pt_regs*, unsigned long); +extern void do_page_fault (struct pt_regs*, unsigned long); +extern void do_debug (struct pt_regs*); +extern void system_call (struct pt_regs*); + +/* + * The vector table must be preceded by a save area (which + * implies it must be in RAM, unless one places RAM immediately + * before a ROM and puts the vector at the start of the ROM (!)) + */ + +#define KRNL 0x01 +#define USER 0x02 + +#define COPROCESSOR(x) \ +{ XCHAL_EXCCAUSE_COPROCESSOR ## x ## _DISABLED, USER, fast_coprocessor } + +typedef struct { + int cause; + int fast; + void* handler; +} dispatch_init_table_t; + +dispatch_init_table_t __init dispatch_init_table[] = { + +{ XCHAL_EXCCAUSE_ILLEGAL_INSTRUCTION, 0, do_illegal_instruction}, +{ XCHAL_EXCCAUSE_SYSTEM_CALL, KRNL, fast_syscall_kernel }, +{ XCHAL_EXCCAUSE_SYSTEM_CALL, USER, fast_syscall_user }, +{ XCHAL_EXCCAUSE_SYSTEM_CALL, 0, system_call }, +/* XCHAL_EXCCAUSE_INSTRUCTION_FETCH unhandled */ +/* XCHAL_EXCCAUSE_LOAD_STORE_ERROR unhandled*/ +{ XCHAL_EXCCAUSE_LEVEL1_INTERRUPT, 0, do_interrupt }, +{ XCHAL_EXCCAUSE_ALLOCA, USER|KRNL, fast_alloca }, +/* XCHAL_EXCCAUSE_INTEGER_DIVIDE_BY_ZERO unhandled */ +/* XCHAL_EXCCAUSE_PRIVILEGED unhandled */ +#if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION +#ifdef CONFIG_UNALIGNED_USER +{ XCHAL_EXCCAUSE_UNALIGNED, USER, fast_unaligned }, +#else +{ XCHAL_EXCCAUSE_UNALIGNED, 0, do_unaligned_user }, +#endif +{ XCHAL_EXCCAUSE_UNALIGNED, KRNL, fast_unaligned }, +#endif +{ XCHAL_EXCCAUSE_ITLB_MISS, 0, do_page_fault }, +{ XCHAL_EXCCAUSE_ITLB_MISS, USER|KRNL, fast_second_level_miss}, +{ XCHAL_EXCCAUSE_ITLB_MULTIHIT, 0, do_multihit }, +{ XCHAL_EXCCAUSE_ITLB_PRIVILEGE, 0, do_page_fault }, +/* XCHAL_EXCCAUSE_SIZE_RESTRICTION unhandled */ +{ XCHAL_EXCCAUSE_FETCH_CACHE_ATTRIBUTE, 0, do_page_fault }, +{ XCHAL_EXCCAUSE_DTLB_MISS, USER|KRNL, fast_second_level_miss}, +{ XCHAL_EXCCAUSE_DTLB_MISS, 0, do_page_fault }, +{ XCHAL_EXCCAUSE_DTLB_MULTIHIT, 0, do_multihit }, +{ XCHAL_EXCCAUSE_DTLB_PRIVILEGE, 0, do_page_fault }, +/* XCHAL_EXCCAUSE_DTLB_SIZE_RESTRICTION unhandled */ +{ XCHAL_EXCCAUSE_STORE_CACHE_ATTRIBUTE, USER|KRNL, fast_store_prohibited }, +{ XCHAL_EXCCAUSE_STORE_CACHE_ATTRIBUTE, 0, do_page_fault }, +{ XCHAL_EXCCAUSE_LOAD_CACHE_ATTRIBUTE, 0, do_page_fault }, +/* XCCHAL_EXCCAUSE_FLOATING_POINT unhandled */ +#if (XCHAL_CP_MASK & 1) +COPROCESSOR(0), +#endif +#if (XCHAL_CP_MASK & 2) +COPROCESSOR(1), +#endif +#if (XCHAL_CP_MASK & 4) +COPROCESSOR(2), +#endif +#if (XCHAL_CP_MASK & 8) +COPROCESSOR(3), +#endif +#if (XCHAL_CP_MASK & 16) +COPROCESSOR(4), +#endif +#if (XCHAL_CP_MASK & 32) +COPROCESSOR(5), +#endif +#if (XCHAL_CP_MASK & 64) +COPROCESSOR(6), +#endif +#if (XCHAL_CP_MASK & 128) +COPROCESSOR(7), +#endif +{ EXCCAUSE_MAPPED_DEBUG, 0, do_debug }, +{ -1, -1, 0 } + +}; + +/* The exception table serves two functions: + * 1. it contains three dispatch tables (fast_user, fast_kernel, default-c) + * 2. it is a temporary memory buffer for the exception handlers. + */ + +unsigned long exc_table[EXC_TABLE_SIZE/4]; + +void die(const char*, struct pt_regs*, long); + +static inline void +__die_if_kernel(const char *str, struct pt_regs *regs, long err) +{ + if (!user_mode(regs)) + die(str, regs, err); +} + +/* + * Unhandled Exceptions. Kill user task or panic if in kernel space. + */ + +void do_unhandled(struct pt_regs *regs, unsigned long exccause) +{ + __die_if_kernel("Caught unhandled exception - should not happen", + regs, SIGKILL); + + /* If in user mode, send SIGILL signal to current process */ + printk("Caught unhandled exception in '%s' " + "(pid = %d, pc = %#010lx) - should not happen\n" + "\tEXCCAUSE is %ld\n", + current->comm, current->pid, regs->pc, exccause); + force_sig(SIGILL, current); +} + +/* + * Multi-hit exception. This if fatal! + */ + +void do_multihit(struct pt_regs *regs, unsigned long exccause) +{ + die("Caught multihit exception", regs, SIGKILL); +} + +/* + * Level-1 interrupt. + * We currently have no priority encoding. + */ + +unsigned long ignored_level1_interrupts; +extern void do_IRQ(int, struct pt_regs *); + +void do_interrupt (struct pt_regs *regs) +{ + unsigned long intread = get_sr (INTREAD); + unsigned long intenable = get_sr (INTENABLE); + int i, mask; + + /* Handle all interrupts (no priorities). + * (Clear the interrupt before processing, in case it's + * edge-triggered or software-generated) + */ + + for (i=0, mask = 1; i < XCHAL_NUM_INTERRUPTS; i++, mask <<= 1) { + if (mask & (intread & intenable)) { + set_sr (mask, INTCLEAR); + do_IRQ (i,regs); + } + } +} + +/* + * Illegal instruction. Fatal if in kernel space. + */ + +void +do_illegal_instruction(struct pt_regs *regs) +{ + __die_if_kernel("Illegal instruction in kernel", regs, SIGKILL); + + /* If in user mode, send SIGILL signal to current process. */ + + printk("Illegal Instruction in '%s' (pid = %d, pc = %#010lx)\n", + current->comm, current->pid, regs->pc); + force_sig(SIGILL, current); +} + + +/* + * Handle unaligned memory accesses from user space. Kill task. + * + * If CONFIG_UNALIGNED_USER is not set, we don't allow unaligned memory + * accesses causes from user space. + */ + +#if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION +#ifndef CONFIG_UNALIGNED_USER +void +do_unaligned_user (struct pt_regs *regs) +{ + siginfo_t info; + + __die_if_kernel("Unhandled unaligned exception in kernel", + regs, SIGKILL); + + current->thread.bad_vaddr = regs->excvaddr; + current->thread.error_code = -3; + printk("Unaligned memory access to %08lx in '%s' " + "(pid = %d, pc = %#010lx)\n", + regs->excvaddr, current->comm, current->pid, regs->pc); + info.si_signo = SIGBUS; + info.si_errno = 0; + info.si_code = BUS_ADRALN; + info.si_addr = (void *) regs->excvaddr; + force_sig_info(SIGSEGV, &info, current); + +} +#endif +#endif + +void +do_debug(struct pt_regs *regs) +{ +#ifdef CONFIG_KGDB + /* If remote debugging is configured AND enabled, we give control to + * kgdb. Otherwise, we fall through, perhaps giving control to the + * native debugger. + */ + + if (gdb_enter) { + extern void gdb_handle_exception(struct pt_regs *); + gdb_handle_exception(regs); + return_from_debug_flag = 1; + return; + } +#endif + + __die_if_kernel("Breakpoint in kernel", regs, SIGKILL); + + /* If in user mode, send SIGTRAP signal to current process */ + + force_sig(SIGTRAP, current); +} + + +/* + * Initialize dispatch tables. + * + * The exception vectors are stored compressed the __init section in the + * dispatch_init_table. This function initializes the following three tables + * from that compressed table: + * - fast user first dispatch table for user exceptions + * - fast kernel first dispatch table for kernel exceptions + * - default C-handler C-handler called by the default fast handler. + * + * See vectors.S for more details. + */ + +#define set_handler(idx,handler) (exc_table[idx] = (unsigned long) (handler)) + +void trap_init(void) +{ + int i; + + /* Setup default vectors. */ + + for(i = 0; i < 64; i++) { + set_handler(EXC_TABLE_FAST_USER/4 + i, user_exception); + set_handler(EXC_TABLE_FAST_KERNEL/4 + i, kernel_exception); + set_handler(EXC_TABLE_DEFAULT/4 + i, do_unhandled); + } + + /* Setup specific handlers. */ + + for(i = 0; dispatch_init_table[i].cause >= 0; i++) { + + int fast = dispatch_init_table[i].fast; + int cause = dispatch_init_table[i].cause; + void *handler = dispatch_init_table[i].handler; + + if (fast == 0) + set_handler (EXC_TABLE_DEFAULT/4 + cause, handler); + if (fast && fast & USER) + set_handler (EXC_TABLE_FAST_USER/4 + cause, handler); + if (fast && fast & KRNL) + set_handler (EXC_TABLE_FAST_KERNEL/4 + cause, handler); + } + + /* Initialize EXCSAVE_1 to hold the address of the exception table. */ + + i = (unsigned long)exc_table; + __asm__ __volatile__("wsr %0, "__stringify(EXCSAVE_1)"\n" : : "a" (i)); +} + +/* + * This function dumps the current valid window frame and other base registers. + */ + +void show_regs(struct pt_regs * regs) +{ + int i, wmask; + + wmask = regs->wmask & ~1; + + for (i = 0; i < 32; i++) { + if (wmask & (1 << (i / 4))) + break; + if ((i % 8) == 0) + printk ("\n" KERN_INFO "a%02d: ", i); + printk("%08lx ", regs->areg[i]); + } + printk("\n"); + + printk("pc: %08lx, ps: %08lx, depc: %08lx, excvaddr: %08lx\n", + regs->pc, regs->ps, regs->depc, regs->excvaddr); + printk("lbeg: %08lx, lend: %08lx lcount: %08lx, sar: %08lx\n", + regs->lbeg, regs->lend, regs->lcount, regs->sar); + if (user_mode(regs)) + printk("wb: %08lx, ws: %08lx, wmask: %08lx, syscall: %ld\n", + regs->windowbase, regs->windowstart, regs->wmask, + regs->syscall); +} + +void show_trace(struct task_struct *task, unsigned long *sp) +{ + unsigned long a0, a1, pc; + unsigned long sp_start, sp_end; + + a1 = (unsigned long)sp; + + if (a1 == 0) + __asm__ __volatile__ ("mov %0, a1\n" : "=a"(a1)); + + + sp_start = a1 & ~(THREAD_SIZE-1); + sp_end = sp_start + THREAD_SIZE; + + printk("Call Trace:"); +#ifdef CONFIG_KALLSYMS + printk("\n"); +#endif + spill_registers(); + + while (a1 > sp_start && a1 < sp_end) { + sp = (unsigned long*)a1; + + a0 = *(sp - 4); + a1 = *(sp - 3); + + if (a1 <= (unsigned long) sp) + break; + + pc = MAKE_PC_FROM_RA(a0, a1); + + if (kernel_text_address(pc)) { + printk(" [<%08lx>] ", pc); + print_symbol("%s\n", pc); + } + } + printk("\n"); +} + +/* + * This routine abuses get_user()/put_user() to reference pointers + * with at least a bit of error checking ... + */ + +static int kstack_depth_to_print = 24; + +void show_stack(struct task_struct *task, unsigned long *sp) +{ + int i = 0; + unsigned long *stack; + + if (sp == 0) + __asm__ __volatile__ ("mov %0, a1\n" : "=a"(sp)); + + stack = sp; + + printk("\nStack: "); + + for (i = 0; i < kstack_depth_to_print; i++) { + if (kstack_end(sp)) + break; + if (i && ((i % 8) == 0)) + printk("\n "); + printk("%08lx ", *sp++); + } + printk("\n"); + show_trace(task, stack); +} + +void dump_stack(void) +{ + show_stack(current, NULL); +} + +EXPORT_SYMBOL(dump_stack); + + +void show_code(unsigned int *pc) +{ + long i; + + printk("\nCode:"); + + for(i = -3 ; i < 6 ; i++) { + unsigned long insn; + if (__get_user(insn, pc + i)) { + printk(" (Bad address in pc)\n"); + break; + } + printk("%c%08lx%c",(i?' ':'<'),insn,(i?' ':'>')); + } +} + +spinlock_t die_lock = SPIN_LOCK_UNLOCKED; + +void die(const char * str, struct pt_regs * regs, long err) +{ + static int die_counter; + int nl = 0; + + console_verbose(); + spin_lock_irq(&die_lock); + + printk("%s: sig: %ld [#%d]\n", str, err, ++die_counter); +#ifdef CONFIG_PREEMPT + printk("PREEMPT "); + nl = 1; +#endif + if (nl) + printk("\n"); + show_regs(regs); + if (!user_mode(regs)) + show_stack(NULL, (unsigned long*)regs->areg[1]); + + spin_unlock_irq(&die_lock); + + if (in_interrupt()) + panic("Fatal exception in interrupt"); + + if (panic_on_oops) { + printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n"); + set_current_state(TASK_UNINTERRUPTIBLE); + schedule_timeout(5 * HZ); + panic("Fatal exception"); + } + do_exit(err); +} + + -- cgit v1.2.3