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-rw-r--r--arch/mips/kernel/traps.c1062
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diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
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index 000000000000..56c36e42e0a6
--- /dev/null
+++ b/arch/mips/kernel/traps.c
@@ -0,0 +1,1062 @@
+/*
+ * 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.
+ *
+ * Copyright (C) 1994 - 1999, 2000, 01 Ralf Baechle
+ * Copyright (C) 1995, 1996 Paul M. Antoine
+ * Copyright (C) 1998 Ulf Carlsson
+ * Copyright (C) 1999 Silicon Graphics, Inc.
+ * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
+ * Copyright (C) 2000, 01 MIPS Technologies, Inc.
+ * Copyright (C) 2002, 2003, 2004 Maciej W. Rozycki
+ */
+#include <linux/config.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+#include <linux/spinlock.h>
+#include <linux/kallsyms.h>
+
+#include <asm/bootinfo.h>
+#include <asm/branch.h>
+#include <asm/break.h>
+#include <asm/cpu.h>
+#include <asm/fpu.h>
+#include <asm/module.h>
+#include <asm/pgtable.h>
+#include <asm/ptrace.h>
+#include <asm/sections.h>
+#include <asm/system.h>
+#include <asm/tlbdebug.h>
+#include <asm/traps.h>
+#include <asm/uaccess.h>
+#include <asm/mmu_context.h>
+#include <asm/watch.h>
+#include <asm/types.h>
+
+extern asmlinkage void handle_tlbm(void);
+extern asmlinkage void handle_tlbl(void);
+extern asmlinkage void handle_tlbs(void);
+extern asmlinkage void handle_adel(void);
+extern asmlinkage void handle_ades(void);
+extern asmlinkage void handle_ibe(void);
+extern asmlinkage void handle_dbe(void);
+extern asmlinkage void handle_sys(void);
+extern asmlinkage void handle_bp(void);
+extern asmlinkage void handle_ri(void);
+extern asmlinkage void handle_cpu(void);
+extern asmlinkage void handle_ov(void);
+extern asmlinkage void handle_tr(void);
+extern asmlinkage void handle_fpe(void);
+extern asmlinkage void handle_mdmx(void);
+extern asmlinkage void handle_watch(void);
+extern asmlinkage void handle_mcheck(void);
+extern asmlinkage void handle_reserved(void);
+
+extern int fpu_emulator_cop1Handler(int xcptno, struct pt_regs *xcp,
+ struct mips_fpu_soft_struct *ctx);
+
+void (*board_be_init)(void);
+int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
+
+/*
+ * These constant is for searching for possible module text segments.
+ * MODULE_RANGE is a guess of how much space is likely to be vmalloced.
+ */
+#define MODULE_RANGE (8*1024*1024)
+
+/*
+ * This routine abuses get_user()/put_user() to reference pointers
+ * with at least a bit of error checking ...
+ */
+void show_stack(struct task_struct *task, unsigned long *sp)
+{
+ const int field = 2 * sizeof(unsigned long);
+ long stackdata;
+ int i;
+
+ if (!sp) {
+ if (task && task != current)
+ sp = (unsigned long *) task->thread.reg29;
+ else
+ sp = (unsigned long *) &sp;
+ }
+
+ printk("Stack :");
+ i = 0;
+ while ((unsigned long) sp & (PAGE_SIZE - 1)) {
+ if (i && ((i % (64 / field)) == 0))
+ printk("\n ");
+ if (i > 39) {
+ printk(" ...");
+ break;
+ }
+
+ if (__get_user(stackdata, sp++)) {
+ printk(" (Bad stack address)");
+ break;
+ }
+
+ printk(" %0*lx", field, stackdata);
+ i++;
+ }
+ printk("\n");
+}
+
+void show_trace(struct task_struct *task, unsigned long *stack)
+{
+ const int field = 2 * sizeof(unsigned long);
+ unsigned long addr;
+
+ if (!stack) {
+ if (task && task != current)
+ stack = (unsigned long *) task->thread.reg29;
+ else
+ stack = (unsigned long *) &stack;
+ }
+
+ printk("Call Trace:");
+#ifdef CONFIG_KALLSYMS
+ printk("\n");
+#endif
+ while (!kstack_end(stack)) {
+ addr = *stack++;
+ if (__kernel_text_address(addr)) {
+ printk(" [<%0*lx>] ", field, addr);
+ print_symbol("%s\n", addr);
+ }
+ }
+ printk("\n");
+}
+
+/*
+ * The architecture-independent dump_stack generator
+ */
+void dump_stack(void)
+{
+ unsigned long stack;
+
+ show_trace(current, &stack);
+}
+
+EXPORT_SYMBOL(dump_stack);
+
+void show_code(unsigned int *pc)
+{
+ long i;
+
+ printk("\nCode:");
+
+ for(i = -3 ; i < 6 ; i++) {
+ unsigned int insn;
+ if (__get_user(insn, pc + i)) {
+ printk(" (Bad address in epc)\n");
+ break;
+ }
+ printk("%c%08x%c", (i?' ':'<'), insn, (i?' ':'>'));
+ }
+}
+
+void show_regs(struct pt_regs *regs)
+{
+ const int field = 2 * sizeof(unsigned long);
+ unsigned int cause = regs->cp0_cause;
+ int i;
+
+ printk("Cpu %d\n", smp_processor_id());
+
+ /*
+ * Saved main processor registers
+ */
+ for (i = 0; i < 32; ) {
+ if ((i % 4) == 0)
+ printk("$%2d :", i);
+ if (i == 0)
+ printk(" %0*lx", field, 0UL);
+ else if (i == 26 || i == 27)
+ printk(" %*s", field, "");
+ else
+ printk(" %0*lx", field, regs->regs[i]);
+
+ i++;
+ if ((i % 4) == 0)
+ printk("\n");
+ }
+
+ printk("Hi : %0*lx\n", field, regs->hi);
+ printk("Lo : %0*lx\n", field, regs->lo);
+
+ /*
+ * Saved cp0 registers
+ */
+ printk("epc : %0*lx ", field, regs->cp0_epc);
+ print_symbol("%s ", regs->cp0_epc);
+ printk(" %s\n", print_tainted());
+ printk("ra : %0*lx ", field, regs->regs[31]);
+ print_symbol("%s\n", regs->regs[31]);
+
+ printk("Status: %08x ", (uint32_t) regs->cp0_status);
+
+ if (regs->cp0_status & ST0_KX)
+ printk("KX ");
+ if (regs->cp0_status & ST0_SX)
+ printk("SX ");
+ if (regs->cp0_status & ST0_UX)
+ printk("UX ");
+ switch (regs->cp0_status & ST0_KSU) {
+ case KSU_USER:
+ printk("USER ");
+ break;
+ case KSU_SUPERVISOR:
+ printk("SUPERVISOR ");
+ break;
+ case KSU_KERNEL:
+ printk("KERNEL ");
+ break;
+ default:
+ printk("BAD_MODE ");
+ break;
+ }
+ if (regs->cp0_status & ST0_ERL)
+ printk("ERL ");
+ if (regs->cp0_status & ST0_EXL)
+ printk("EXL ");
+ if (regs->cp0_status & ST0_IE)
+ printk("IE ");
+ printk("\n");
+
+ printk("Cause : %08x\n", cause);
+
+ cause = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
+ if (1 <= cause && cause <= 5)
+ printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
+
+ printk("PrId : %08x\n", read_c0_prid());
+}
+
+void show_registers(struct pt_regs *regs)
+{
+ show_regs(regs);
+ print_modules();
+ printk("Process %s (pid: %d, threadinfo=%p, task=%p)\n",
+ current->comm, current->pid, current_thread_info(), current);
+ show_stack(current, (long *) regs->regs[29]);
+ show_trace(current, (long *) regs->regs[29]);
+ show_code((unsigned int *) regs->cp0_epc);
+ printk("\n");
+}
+
+static DEFINE_SPINLOCK(die_lock);
+
+NORET_TYPE void __die(const char * str, struct pt_regs * regs,
+ const char * file, const char * func, unsigned long line)
+{
+ static int die_counter;
+
+ console_verbose();
+ spin_lock_irq(&die_lock);
+ printk("%s", str);
+ if (file && func)
+ printk(" in %s:%s, line %ld", file, func, line);
+ printk("[#%d]:\n", ++die_counter);
+ show_registers(regs);
+ spin_unlock_irq(&die_lock);
+ do_exit(SIGSEGV);
+}
+
+void __die_if_kernel(const char * str, struct pt_regs * regs,
+ const char * file, const char * func, unsigned long line)
+{
+ if (!user_mode(regs))
+ __die(str, regs, file, func, line);
+}
+
+extern const struct exception_table_entry __start___dbe_table[];
+extern const struct exception_table_entry __stop___dbe_table[];
+
+void __declare_dbe_table(void)
+{
+ __asm__ __volatile__(
+ ".section\t__dbe_table,\"a\"\n\t"
+ ".previous"
+ );
+}
+
+/* Given an address, look for it in the exception tables. */
+static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
+{
+ const struct exception_table_entry *e;
+
+ e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr);
+ if (!e)
+ e = search_module_dbetables(addr);
+ return e;
+}
+
+asmlinkage void do_be(struct pt_regs *regs)
+{
+ const int field = 2 * sizeof(unsigned long);
+ const struct exception_table_entry *fixup = NULL;
+ int data = regs->cp0_cause & 4;
+ int action = MIPS_BE_FATAL;
+
+ /* XXX For now. Fixme, this searches the wrong table ... */
+ if (data && !user_mode(regs))
+ fixup = search_dbe_tables(exception_epc(regs));
+
+ if (fixup)
+ action = MIPS_BE_FIXUP;
+
+ if (board_be_handler)
+ action = board_be_handler(regs, fixup != 0);
+
+ switch (action) {
+ case MIPS_BE_DISCARD:
+ return;
+ case MIPS_BE_FIXUP:
+ if (fixup) {
+ regs->cp0_epc = fixup->nextinsn;
+ return;
+ }
+ break;
+ default:
+ break;
+ }
+
+ /*
+ * Assume it would be too dangerous to continue ...
+ */
+ printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
+ data ? "Data" : "Instruction",
+ field, regs->cp0_epc, field, regs->regs[31]);
+ die_if_kernel("Oops", regs);
+ force_sig(SIGBUS, current);
+}
+
+static inline int get_insn_opcode(struct pt_regs *regs, unsigned int *opcode)
+{
+ unsigned int *epc;
+
+ epc = (unsigned int *) regs->cp0_epc +
+ ((regs->cp0_cause & CAUSEF_BD) != 0);
+ if (!get_user(*opcode, epc))
+ return 0;
+
+ force_sig(SIGSEGV, current);
+ return 1;
+}
+
+/*
+ * ll/sc emulation
+ */
+
+#define OPCODE 0xfc000000
+#define BASE 0x03e00000
+#define RT 0x001f0000
+#define OFFSET 0x0000ffff
+#define LL 0xc0000000
+#define SC 0xe0000000
+
+/*
+ * The ll_bit is cleared by r*_switch.S
+ */
+
+unsigned long ll_bit;
+
+static struct task_struct *ll_task = NULL;
+
+static inline void simulate_ll(struct pt_regs *regs, unsigned int opcode)
+{
+ unsigned long value, *vaddr;
+ long offset;
+ int signal = 0;
+
+ /*
+ * analyse the ll instruction that just caused a ri exception
+ * and put the referenced address to addr.
+ */
+
+ /* sign extend offset */
+ offset = opcode & OFFSET;
+ offset <<= 16;
+ offset >>= 16;
+
+ vaddr = (unsigned long *)((long)(regs->regs[(opcode & BASE) >> 21]) + offset);
+
+ if ((unsigned long)vaddr & 3) {
+ signal = SIGBUS;
+ goto sig;
+ }
+ if (get_user(value, vaddr)) {
+ signal = SIGSEGV;
+ goto sig;
+ }
+
+ preempt_disable();
+
+ if (ll_task == NULL || ll_task == current) {
+ ll_bit = 1;
+ } else {
+ ll_bit = 0;
+ }
+ ll_task = current;
+
+ preempt_enable();
+
+ regs->regs[(opcode & RT) >> 16] = value;
+
+ compute_return_epc(regs);
+ return;
+
+sig:
+ force_sig(signal, current);
+}
+
+static inline void simulate_sc(struct pt_regs *regs, unsigned int opcode)
+{
+ unsigned long *vaddr, reg;
+ long offset;
+ int signal = 0;
+
+ /*
+ * analyse the sc instruction that just caused a ri exception
+ * and put the referenced address to addr.
+ */
+
+ /* sign extend offset */
+ offset = opcode & OFFSET;
+ offset <<= 16;
+ offset >>= 16;
+
+ vaddr = (unsigned long *)((long)(regs->regs[(opcode & BASE) >> 21]) + offset);
+ reg = (opcode & RT) >> 16;
+
+ if ((unsigned long)vaddr & 3) {
+ signal = SIGBUS;
+ goto sig;
+ }
+
+ preempt_disable();
+
+ if (ll_bit == 0 || ll_task != current) {
+ regs->regs[reg] = 0;
+ preempt_enable();
+ compute_return_epc(regs);
+ return;
+ }
+
+ preempt_enable();
+
+ if (put_user(regs->regs[reg], vaddr)) {
+ signal = SIGSEGV;
+ goto sig;
+ }
+
+ regs->regs[reg] = 1;
+
+ compute_return_epc(regs);
+ return;
+
+sig:
+ force_sig(signal, current);
+}
+
+/*
+ * ll uses the opcode of lwc0 and sc uses the opcode of swc0. That is both
+ * opcodes are supposed to result in coprocessor unusable exceptions if
+ * executed on ll/sc-less processors. That's the theory. In practice a
+ * few processors such as NEC's VR4100 throw reserved instruction exceptions
+ * instead, so we're doing the emulation thing in both exception handlers.
+ */
+static inline int simulate_llsc(struct pt_regs *regs)
+{
+ unsigned int opcode;
+
+ if (unlikely(get_insn_opcode(regs, &opcode)))
+ return -EFAULT;
+
+ if ((opcode & OPCODE) == LL) {
+ simulate_ll(regs, opcode);
+ return 0;
+ }
+ if ((opcode & OPCODE) == SC) {
+ simulate_sc(regs, opcode);
+ return 0;
+ }
+
+ return -EFAULT; /* Strange things going on ... */
+}
+
+asmlinkage void do_ov(struct pt_regs *regs)
+{
+ siginfo_t info;
+
+ info.si_code = FPE_INTOVF;
+ info.si_signo = SIGFPE;
+ info.si_errno = 0;
+ info.si_addr = (void *)regs->cp0_epc;
+ force_sig_info(SIGFPE, &info, current);
+}
+
+/*
+ * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
+ */
+asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
+{
+ if (fcr31 & FPU_CSR_UNI_X) {
+ int sig;
+
+ preempt_disable();
+
+ /*
+ * Unimplemented operation exception. If we've got the full
+ * software emulator on-board, let's use it...
+ *
+ * Force FPU to dump state into task/thread context. We're
+ * moving a lot of data here for what is probably a single
+ * instruction, but the alternative is to pre-decode the FP
+ * register operands before invoking the emulator, which seems
+ * a bit extreme for what should be an infrequent event.
+ */
+ save_fp(current);
+
+ /* Run the emulator */
+ sig = fpu_emulator_cop1Handler (0, regs,
+ &current->thread.fpu.soft);
+
+ /*
+ * We can't allow the emulated instruction to leave any of
+ * the cause bit set in $fcr31.
+ */
+ current->thread.fpu.soft.fcr31 &= ~FPU_CSR_ALL_X;
+
+ /* Restore the hardware register state */
+ restore_fp(current);
+
+ preempt_enable();
+
+ /* If something went wrong, signal */
+ if (sig)
+ force_sig(sig, current);
+
+ return;
+ }
+
+ force_sig(SIGFPE, current);
+}
+
+asmlinkage void do_bp(struct pt_regs *regs)
+{
+ unsigned int opcode, bcode;
+ siginfo_t info;
+
+ die_if_kernel("Break instruction in kernel code", regs);
+
+ if (get_insn_opcode(regs, &opcode))
+ return;
+
+ /*
+ * There is the ancient bug in the MIPS assemblers that the break
+ * code starts left to bit 16 instead to bit 6 in the opcode.
+ * Gas is bug-compatible, but not always, grrr...
+ * We handle both cases with a simple heuristics. --macro
+ */
+ bcode = ((opcode >> 6) & ((1 << 20) - 1));
+ if (bcode < (1 << 10))
+ bcode <<= 10;
+
+ /*
+ * (A short test says that IRIX 5.3 sends SIGTRAP for all break
+ * insns, even for break codes that indicate arithmetic failures.
+ * Weird ...)
+ * But should we continue the brokenness??? --macro
+ */
+ switch (bcode) {
+ case BRK_OVERFLOW << 10:
+ case BRK_DIVZERO << 10:
+ if (bcode == (BRK_DIVZERO << 10))
+ info.si_code = FPE_INTDIV;
+ else
+ info.si_code = FPE_INTOVF;
+ info.si_signo = SIGFPE;
+ info.si_errno = 0;
+ info.si_addr = (void *)regs->cp0_epc;
+ force_sig_info(SIGFPE, &info, current);
+ break;
+ default:
+ force_sig(SIGTRAP, current);
+ }
+}
+
+asmlinkage void do_tr(struct pt_regs *regs)
+{
+ unsigned int opcode, tcode = 0;
+ siginfo_t info;
+
+ die_if_kernel("Trap instruction in kernel code", regs);
+
+ if (get_insn_opcode(regs, &opcode))
+ return;
+
+ /* Immediate versions don't provide a code. */
+ if (!(opcode & OPCODE))
+ tcode = ((opcode >> 6) & ((1 << 10) - 1));
+
+ /*
+ * (A short test says that IRIX 5.3 sends SIGTRAP for all trap
+ * insns, even for trap codes that indicate arithmetic failures.
+ * Weird ...)
+ * But should we continue the brokenness??? --macro
+ */
+ switch (tcode) {
+ case BRK_OVERFLOW:
+ case BRK_DIVZERO:
+ if (tcode == BRK_DIVZERO)
+ info.si_code = FPE_INTDIV;
+ else
+ info.si_code = FPE_INTOVF;
+ info.si_signo = SIGFPE;
+ info.si_errno = 0;
+ info.si_addr = (void *)regs->cp0_epc;
+ force_sig_info(SIGFPE, &info, current);
+ break;
+ default:
+ force_sig(SIGTRAP, current);
+ }
+}
+
+asmlinkage void do_ri(struct pt_regs *regs)
+{
+ die_if_kernel("Reserved instruction in kernel code", regs);
+
+ if (!cpu_has_llsc)
+ if (!simulate_llsc(regs))
+ return;
+
+ force_sig(SIGILL, current);
+}
+
+asmlinkage void do_cpu(struct pt_regs *regs)
+{
+ unsigned int cpid;
+
+ die_if_kernel("do_cpu invoked from kernel context!", regs);
+
+ cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
+
+ switch (cpid) {
+ case 0:
+ if (cpu_has_llsc)
+ break;
+
+ if (!simulate_llsc(regs))
+ return;
+ break;
+
+ case 1:
+ preempt_disable();
+
+ own_fpu();
+ if (used_math()) { /* Using the FPU again. */
+ restore_fp(current);
+ } else { /* First time FPU user. */
+ init_fpu();
+ set_used_math();
+ }
+
+ if (!cpu_has_fpu) {
+ int sig = fpu_emulator_cop1Handler(0, regs,
+ &current->thread.fpu.soft);
+ if (sig)
+ force_sig(sig, current);
+ }
+
+ preempt_enable();
+
+ return;
+
+ case 2:
+ case 3:
+ break;
+ }
+
+ force_sig(SIGILL, current);
+}
+
+asmlinkage void do_mdmx(struct pt_regs *regs)
+{
+ force_sig(SIGILL, current);
+}
+
+asmlinkage void do_watch(struct pt_regs *regs)
+{
+ /*
+ * We use the watch exception where available to detect stack
+ * overflows.
+ */
+ dump_tlb_all();
+ show_regs(regs);
+ panic("Caught WATCH exception - probably caused by stack overflow.");
+}
+
+asmlinkage void do_mcheck(struct pt_regs *regs)
+{
+ show_regs(regs);
+ dump_tlb_all();
+ /*
+ * Some chips may have other causes of machine check (e.g. SB1
+ * graduation timer)
+ */
+ panic("Caught Machine Check exception - %scaused by multiple "
+ "matching entries in the TLB.",
+ (regs->cp0_status & ST0_TS) ? "" : "not ");
+}
+
+asmlinkage void do_reserved(struct pt_regs *regs)
+{
+ /*
+ * Game over - no way to handle this if it ever occurs. Most probably
+ * caused by a new unknown cpu type or after another deadly
+ * hard/software error.
+ */
+ show_regs(regs);
+ panic("Caught reserved exception %ld - should not happen.",
+ (regs->cp0_cause & 0x7f) >> 2);
+}
+
+/*
+ * Some MIPS CPUs can enable/disable for cache parity detection, but do
+ * it different ways.
+ */
+static inline void parity_protection_init(void)
+{
+ switch (current_cpu_data.cputype) {
+ case CPU_24K:
+ /* 24K cache parity not currently implemented in FPGA */
+ printk(KERN_INFO "Disable cache parity protection for "
+ "MIPS 24K CPU.\n");
+ write_c0_ecc(read_c0_ecc() & ~0x80000000);
+ break;
+ case CPU_5KC:
+ /* Set the PE bit (bit 31) in the c0_ecc register. */
+ printk(KERN_INFO "Enable cache parity protection for "
+ "MIPS 5KC/24K CPUs.\n");
+ write_c0_ecc(read_c0_ecc() | 0x80000000);
+ break;
+ case CPU_20KC:
+ case CPU_25KF:
+ /* Clear the DE bit (bit 16) in the c0_status register. */
+ printk(KERN_INFO "Enable cache parity protection for "
+ "MIPS 20KC/25KF CPUs.\n");
+ clear_c0_status(ST0_DE);
+ break;
+ default:
+ break;
+ }
+}
+
+asmlinkage void cache_parity_error(void)
+{
+ const int field = 2 * sizeof(unsigned long);
+ unsigned int reg_val;
+
+ /* For the moment, report the problem and hang. */
+ printk("Cache error exception:\n");
+ printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
+ reg_val = read_c0_cacheerr();
+ printk("c0_cacheerr == %08x\n", reg_val);
+
+ printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
+ reg_val & (1<<30) ? "secondary" : "primary",
+ reg_val & (1<<31) ? "data" : "insn");
+ printk("Error bits: %s%s%s%s%s%s%s\n",
+ reg_val & (1<<29) ? "ED " : "",
+ reg_val & (1<<28) ? "ET " : "",
+ reg_val & (1<<26) ? "EE " : "",
+ reg_val & (1<<25) ? "EB " : "",
+ reg_val & (1<<24) ? "EI " : "",
+ reg_val & (1<<23) ? "E1 " : "",
+ reg_val & (1<<22) ? "E0 " : "");
+ printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
+
+#if defined(CONFIG_CPU_MIPS32) || defined (CONFIG_CPU_MIPS64)
+ if (reg_val & (1<<22))
+ printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
+
+ if (reg_val & (1<<23))
+ printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
+#endif
+
+ panic("Can't handle the cache error!");
+}
+
+/*
+ * SDBBP EJTAG debug exception handler.
+ * We skip the instruction and return to the next instruction.
+ */
+void ejtag_exception_handler(struct pt_regs *regs)
+{
+ const int field = 2 * sizeof(unsigned long);
+ unsigned long depc, old_epc;
+ unsigned int debug;
+
+ printk("SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
+ depc = read_c0_depc();
+ debug = read_c0_debug();
+ printk("c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
+ if (debug & 0x80000000) {
+ /*
+ * In branch delay slot.
+ * We cheat a little bit here and use EPC to calculate the
+ * debug return address (DEPC). EPC is restored after the
+ * calculation.
+ */
+ old_epc = regs->cp0_epc;
+ regs->cp0_epc = depc;
+ __compute_return_epc(regs);
+ depc = regs->cp0_epc;
+ regs->cp0_epc = old_epc;
+ } else
+ depc += 4;
+ write_c0_depc(depc);
+
+#if 0
+ printk("\n\n----- Enable EJTAG single stepping ----\n\n");
+ write_c0_debug(debug | 0x100);
+#endif
+}
+
+/*
+ * NMI exception handler.
+ */
+void nmi_exception_handler(struct pt_regs *regs)
+{
+ printk("NMI taken!!!!\n");
+ die("NMI", regs);
+ while(1) ;
+}
+
+unsigned long exception_handlers[32];
+
+/*
+ * As a side effect of the way this is implemented we're limited
+ * to interrupt handlers in the address range from
+ * KSEG0 <= x < KSEG0 + 256mb on the Nevada. Oh well ...
+ */
+void *set_except_vector(int n, void *addr)
+{
+ unsigned long handler = (unsigned long) addr;
+ unsigned long old_handler = exception_handlers[n];
+
+ exception_handlers[n] = handler;
+ if (n == 0 && cpu_has_divec) {
+ *(volatile u32 *)(CAC_BASE + 0x200) = 0x08000000 |
+ (0x03ffffff & (handler >> 2));
+ flush_icache_range(CAC_BASE + 0x200, CAC_BASE + 0x204);
+ }
+ return (void *)old_handler;
+}
+
+/*
+ * This is used by native signal handling
+ */
+asmlinkage int (*save_fp_context)(struct sigcontext *sc);
+asmlinkage int (*restore_fp_context)(struct sigcontext *sc);
+
+extern asmlinkage int _save_fp_context(struct sigcontext *sc);
+extern asmlinkage int _restore_fp_context(struct sigcontext *sc);
+
+extern asmlinkage int fpu_emulator_save_context(struct sigcontext *sc);
+extern asmlinkage int fpu_emulator_restore_context(struct sigcontext *sc);
+
+static inline void signal_init(void)
+{
+ if (cpu_has_fpu) {
+ save_fp_context = _save_fp_context;
+ restore_fp_context = _restore_fp_context;
+ } else {
+ save_fp_context = fpu_emulator_save_context;
+ restore_fp_context = fpu_emulator_restore_context;
+ }
+}
+
+#ifdef CONFIG_MIPS32_COMPAT
+
+/*
+ * This is used by 32-bit signal stuff on the 64-bit kernel
+ */
+asmlinkage int (*save_fp_context32)(struct sigcontext32 *sc);
+asmlinkage int (*restore_fp_context32)(struct sigcontext32 *sc);
+
+extern asmlinkage int _save_fp_context32(struct sigcontext32 *sc);
+extern asmlinkage int _restore_fp_context32(struct sigcontext32 *sc);
+
+extern asmlinkage int fpu_emulator_save_context32(struct sigcontext32 *sc);
+extern asmlinkage int fpu_emulator_restore_context32(struct sigcontext32 *sc);
+
+static inline void signal32_init(void)
+{
+ if (cpu_has_fpu) {
+ save_fp_context32 = _save_fp_context32;
+ restore_fp_context32 = _restore_fp_context32;
+ } else {
+ save_fp_context32 = fpu_emulator_save_context32;
+ restore_fp_context32 = fpu_emulator_restore_context32;
+ }
+}
+#endif
+
+extern void cpu_cache_init(void);
+extern void tlb_init(void);
+
+void __init per_cpu_trap_init(void)
+{
+ unsigned int cpu = smp_processor_id();
+ unsigned int status_set = ST0_CU0;
+
+ /*
+ * Disable coprocessors and select 32-bit or 64-bit addressing
+ * and the 16/32 or 32/32 FPR register model. Reset the BEV
+ * flag that some firmware may have left set and the TS bit (for
+ * IP27). Set XX for ISA IV code to work.
+ */
+#ifdef CONFIG_MIPS64
+ status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
+#endif
+ if (current_cpu_data.isa_level == MIPS_CPU_ISA_IV)
+ status_set |= ST0_XX;
+ change_c0_status(ST0_CU|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
+ status_set);
+
+ /*
+ * Some MIPS CPUs have a dedicated interrupt vector which reduces the
+ * interrupt processing overhead. Use it where available.
+ */
+ if (cpu_has_divec)
+ set_c0_cause(CAUSEF_IV);
+
+ cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
+ TLBMISS_HANDLER_SETUP();
+
+ atomic_inc(&init_mm.mm_count);
+ current->active_mm = &init_mm;
+ BUG_ON(current->mm);
+ enter_lazy_tlb(&init_mm, current);
+
+ cpu_cache_init();
+ tlb_init();
+}
+
+void __init trap_init(void)
+{
+ extern char except_vec3_generic, except_vec3_r4000;
+ extern char except_vec_ejtag_debug;
+ extern char except_vec4;
+ unsigned long i;
+
+ per_cpu_trap_init();
+
+ /*
+ * Copy the generic exception handlers to their final destination.
+ * This will be overriden later as suitable for a particular
+ * configuration.
+ */
+ memcpy((void *)(CAC_BASE + 0x180), &except_vec3_generic, 0x80);
+
+ /*
+ * Setup default vectors
+ */
+ for (i = 0; i <= 31; i++)
+ set_except_vector(i, handle_reserved);
+
+ /*
+ * Copy the EJTAG debug exception vector handler code to it's final
+ * destination.
+ */
+ if (cpu_has_ejtag)
+ memcpy((void *)(CAC_BASE + 0x300), &except_vec_ejtag_debug, 0x80);
+
+ /*
+ * Only some CPUs have the watch exceptions.
+ */
+ if (cpu_has_watch)
+ set_except_vector(23, handle_watch);
+
+ /*
+ * Some MIPS CPUs have a dedicated interrupt vector which reduces the
+ * interrupt processing overhead. Use it where available.
+ */
+ if (cpu_has_divec)
+ memcpy((void *)(CAC_BASE + 0x200), &except_vec4, 0x8);
+
+ /*
+ * Some CPUs can enable/disable for cache parity detection, but does
+ * it different ways.
+ */
+ parity_protection_init();
+
+ /*
+ * The Data Bus Errors / Instruction Bus Errors are signaled
+ * by external hardware. Therefore these two exceptions
+ * may have board specific handlers.
+ */
+ if (board_be_init)
+ board_be_init();
+
+ set_except_vector(1, handle_tlbm);
+ set_except_vector(2, handle_tlbl);
+ set_except_vector(3, handle_tlbs);
+
+ set_except_vector(4, handle_adel);
+ set_except_vector(5, handle_ades);
+
+ set_except_vector(6, handle_ibe);
+ set_except_vector(7, handle_dbe);
+
+ set_except_vector(8, handle_sys);
+ set_except_vector(9, handle_bp);
+ set_except_vector(10, handle_ri);
+ set_except_vector(11, handle_cpu);
+ set_except_vector(12, handle_ov);
+ set_except_vector(13, handle_tr);
+ set_except_vector(22, handle_mdmx);
+
+ if (cpu_has_fpu && !cpu_has_nofpuex)
+ set_except_vector(15, handle_fpe);
+
+ if (cpu_has_mcheck)
+ set_except_vector(24, handle_mcheck);
+
+ if (cpu_has_vce)
+ /* Special exception: R4[04]00 uses also the divec space. */
+ memcpy((void *)(CAC_BASE + 0x180), &except_vec3_r4000, 0x100);
+ else if (cpu_has_4kex)
+ memcpy((void *)(CAC_BASE + 0x180), &except_vec3_generic, 0x80);
+ else
+ memcpy((void *)(CAC_BASE + 0x080), &except_vec3_generic, 0x80);
+
+ if (current_cpu_data.cputype == CPU_R6000 ||
+ current_cpu_data.cputype == CPU_R6000A) {
+ /*
+ * The R6000 is the only R-series CPU that features a machine
+ * check exception (similar to the R4000 cache error) and
+ * unaligned ldc1/sdc1 exception. The handlers have not been
+ * written yet. Well, anyway there is no R6000 machine on the
+ * current list of targets for Linux/MIPS.
+ * (Duh, crap, there is someone with a triple R6k machine)
+ */
+ //set_except_vector(14, handle_mc);
+ //set_except_vector(15, handle_ndc);
+ }
+
+ signal_init();
+#ifdef CONFIG_MIPS32_COMPAT
+ signal32_init();
+#endif
+
+ flush_icache_range(CAC_BASE, CAC_BASE + 0x400);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-22 17:06:09 +0100