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732c0c3c70
linux_dsm_epyc7002/arch/mips/kernel/traps.c
Paul Burton 732c0c3c70 MIPS: fix MSA context for tasks which don't use FP first 
If a task does not execute scalar FP instructions prior to using MSA
then the flags indicating that the task has live MSA context were not
being set. The upper 64b of each vector register would then be lost
upon the tasks first context switch after using MSA.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7500/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-08-02 00:06:44 +02:00

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54 KiB
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/*
* 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, 06 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) 2002, 2003, 2004, 2005, 2007 Maciej W. Rozycki
* Copyright (C) 2000, 2001, 2012 MIPS Technologies, Inc. All rights reserved.
* Copyright (C) 2014, Imagination Technologies Ltd.
*/
#include <linux/bug.h>
#include <linux/compiler.h>
#include <linux/context_tracking.h>
#include <linux/cpu_pm.h>
#include <linux/kexec.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
#include <linux/kallsyms.h>
#include <linux/bootmem.h>
#include <linux/interrupt.h>
#include <linux/ptrace.h>
#include <linux/kgdb.h>
#include <linux/kdebug.h>
#include <linux/kprobes.h>
#include <linux/notifier.h>
#include <linux/kdb.h>
#include <linux/irq.h>
#include <linux/perf_event.h>
#include <asm/bootinfo.h>
#include <asm/branch.h>
#include <asm/break.h>
#include <asm/cop2.h>
#include <asm/cpu.h>
#include <asm/cpu-type.h>
#include <asm/dsp.h>
#include <asm/fpu.h>
#include <asm/fpu_emulator.h>
#include <asm/idle.h>
#include <asm/mipsregs.h>
#include <asm/mipsmtregs.h>
#include <asm/module.h>
#include <asm/msa.h>
#include <asm/pgtable.h>
#include <asm/ptrace.h>
#include <asm/sections.h>
#include <asm/tlbdebug.h>
#include <asm/traps.h>
#include <asm/uaccess.h>
#include <asm/watch.h>
#include <asm/mmu_context.h>
#include <asm/types.h>
#include <asm/stacktrace.h>
#include <asm/uasm.h>
extern void check_wait(void);
extern asmlinkage void rollback_handle_int(void);
extern asmlinkage void handle_int(void);
extern u32 handle_tlbl[];
extern u32 handle_tlbs[];
extern u32 handle_tlbm[];
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_ri_rdhwr_vivt(void);
extern asmlinkage void handle_ri_rdhwr(void);
extern asmlinkage void handle_cpu(void);
extern asmlinkage void handle_ov(void);
extern asmlinkage void handle_tr(void);
extern asmlinkage void handle_msa_fpe(void);
extern asmlinkage void handle_fpe(void);
extern asmlinkage void handle_ftlb(void);
extern asmlinkage void handle_msa(void);
extern asmlinkage void handle_mdmx(void);
extern asmlinkage void handle_watch(void);
extern asmlinkage void handle_mt(void);
extern asmlinkage void handle_dsp(void);
extern asmlinkage void handle_mcheck(void);
extern asmlinkage void handle_reserved(void);
extern void tlb_do_page_fault_0(void);
void (*board_be_init)(void);
int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
void (*board_nmi_handler_setup)(void);
void (*board_ejtag_handler_setup)(void);
void (*board_bind_eic_interrupt)(int irq, int regset);
void (*board_ebase_setup)(void);
void(*board_cache_error_setup)(void);
static void show_raw_backtrace(unsigned long reg29)
{
unsigned long *sp = (unsigned long *)(reg29 & ~3);
unsigned long addr;
printk("Call Trace:");
#ifdef CONFIG_KALLSYMS
printk("\n");
#endif
while (!kstack_end(sp)) {
unsigned long __user *p =
(unsigned long __user *)(unsigned long)sp++;
if (__get_user(addr, p)) {
printk(" (Bad stack address)");
break;
}
if (__kernel_text_address(addr))
print_ip_sym(addr);
}
printk("\n");
}
#ifdef CONFIG_KALLSYMS
int raw_show_trace;
static int __init set_raw_show_trace(char *str)
{
raw_show_trace = 1;
return 1;
}
__setup("raw_show_trace", set_raw_show_trace);
#endif
static void show_backtrace(struct task_struct *task, const struct pt_regs *regs)
{
unsigned long sp = regs->regs[29];
unsigned long ra = regs->regs[31];
unsigned long pc = regs->cp0_epc;
if (!task)
task = current;
if (raw_show_trace || !__kernel_text_address(pc)) {
show_raw_backtrace(sp);
return;
}
printk("Call Trace:\n");
do {
print_ip_sym(pc);
pc = unwind_stack(task, &sp, pc, &ra);
} while (pc);
printk("\n");
}
/*
* This routine abuses get_user()/put_user() to reference pointers
* with at least a bit of error checking ...
*/
static void show_stacktrace(struct task_struct *task,
const struct pt_regs *regs)
{
const int field = 2 * sizeof(unsigned long);
long stackdata;
int i;
unsigned long __user *sp = (unsigned long __user *)regs->regs[29];
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");
show_backtrace(task, regs);
}
void show_stack(struct task_struct *task, unsigned long *sp)
{
struct pt_regs regs;
if (sp) {
regs.regs[29] = (unsigned long)sp;
regs.regs[31] = 0;
regs.cp0_epc = 0;
} else {
if (task && task != current) {
regs.regs[29] = task->thread.reg29;
regs.regs[31] = 0;
regs.cp0_epc = task->thread.reg31;
#ifdef CONFIG_KGDB_KDB
} else if (atomic_read(&kgdb_active) != -1 &&
kdb_current_regs) {
memcpy(&regs, kdb_current_regs, sizeof(regs));
#endif /* CONFIG_KGDB_KDB */
} else {
prepare_frametrace(&regs);
}
}
show_stacktrace(task, &regs);
}
static void show_code(unsigned int __user *pc)
{
long i;
unsigned short __user *pc16 = NULL;
printk("\nCode:");
if ((unsigned long)pc & 1)
pc16 = (unsigned short __user *)((unsigned long)pc & ~1);
for(i = -3 ; i < 6 ; i++) {
unsigned int insn;
if (pc16 ? __get_user(insn, pc16 + i) : __get_user(insn, pc + i)) {
printk(" (Bad address in epc)\n");
break;
}
printk("%c%0*x%c", (i?' ':'<'), pc16 ? 4 : 8, insn, (i?' ':'>'));
}
}
static void __show_regs(const struct pt_regs *regs)
{
const int field = 2 * sizeof(unsigned long);
unsigned int cause = regs->cp0_cause;
int i;
show_regs_print_info(KERN_DEFAULT);
/*
* 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");
}
#ifdef CONFIG_CPU_HAS_SMARTMIPS
printk("Acx : %0*lx\n", field, regs->acx);
#endif
printk("Hi : %0*lx\n", field, regs->hi);
printk("Lo : %0*lx\n", field, regs->lo);
/*
* Saved cp0 registers
*/
printk("epc : %0*lx %pS\n", field, regs->cp0_epc,
(void *) regs->cp0_epc);
printk(" %s\n", print_tainted());
printk("ra : %0*lx %pS\n", field, regs->regs[31],
(void *) regs->regs[31]);
printk("Status: %08x ", (uint32_t) regs->cp0_status);
if (cpu_has_3kex) {
if (regs->cp0_status & ST0_KUO)
printk("KUo ");
if (regs->cp0_status & ST0_IEO)
printk("IEo ");
if (regs->cp0_status & ST0_KUP)
printk("KUp ");
if (regs->cp0_status & ST0_IEP)
printk("IEp ");
if (regs->cp0_status & ST0_KUC)
printk("KUc ");
if (regs->cp0_status & ST0_IEC)
printk("IEc ");
} else if (cpu_has_4kex) {
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 (%s)\n", read_c0_prid(),
cpu_name_string());
}
/*
* FIXME: really the generic show_regs should take a const pointer argument.
*/
void show_regs(struct pt_regs *regs)
{
__show_regs((struct pt_regs *)regs);
}
void show_registers(struct pt_regs *regs)
{
const int field = 2 * sizeof(unsigned long);
mm_segment_t old_fs = get_fs();
__show_regs(regs);
print_modules();
printk("Process %s (pid: %d, threadinfo=%p, task=%p, tls=%0*lx)\n",
current->comm, current->pid, current_thread_info(), current,
field, current_thread_info()->tp_value);
if (cpu_has_userlocal) {
unsigned long tls;
tls = read_c0_userlocal();
if (tls != current_thread_info()->tp_value)
printk("*HwTLS: %0*lx\n", field, tls);
}
if (!user_mode(regs))
/* Necessary for getting the correct stack content */
set_fs(KERNEL_DS);
show_stacktrace(current, regs);
show_code((unsigned int __user *) regs->cp0_epc);
printk("\n");
set_fs(old_fs);
}
static int regs_to_trapnr(struct pt_regs *regs)
{
return (regs->cp0_cause >> 2) & 0x1f;
}
static DEFINE_RAW_SPINLOCK(die_lock);
void __noreturn die(const char *str, struct pt_regs *regs)
{
static int die_counter;
int sig = SIGSEGV;
oops_enter();
if (notify_die(DIE_OOPS, str, regs, 0, regs_to_trapnr(regs),
SIGSEGV) == NOTIFY_STOP)
sig = 0;
console_verbose();
raw_spin_lock_irq(&die_lock);
bust_spinlocks(1);
printk("%s[#%d]:\n", str, ++die_counter);
show_registers(regs);
add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
raw_spin_unlock_irq(&die_lock);
oops_exit();
if (in_interrupt())
panic("Fatal exception in interrupt");
if (panic_on_oops) {
printk(KERN_EMERG "Fatal exception: panic in 5 seconds");
ssleep(5);
panic("Fatal exception");
}
if (regs && kexec_should_crash(current))
crash_kexec(regs);
do_exit(sig);
}
extern struct exception_table_entry __start___dbe_table[];
extern struct exception_table_entry __stop___dbe_table[];
__asm__(
" .section __dbe_table, \"a\"\n"
" .previous \n");
/* 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;
enum ctx_state prev_state;
prev_state = exception_enter();
/* 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 != NULL);
switch (action) {
case MIPS_BE_DISCARD:
goto out;
case MIPS_BE_FIXUP:
if (fixup) {
regs->cp0_epc = fixup->nextinsn;
goto out;
}
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]);
if (notify_die(DIE_OOPS, "bus error", regs, 0, regs_to_trapnr(regs),
SIGBUS) == NOTIFY_STOP)
goto out;
die_if_kernel("Oops", regs);
force_sig(SIGBUS, current);
out:
exception_exit(prev_state);
}
/*
* ll/sc, rdhwr, sync emulation
*/
#define OPCODE 0xfc000000
#define BASE 0x03e00000
#define RT 0x001f0000
#define OFFSET 0x0000ffff
#define LL 0xc0000000
#define SC 0xe0000000
#define SPEC0 0x00000000
#define SPEC3 0x7c000000
#define RD 0x0000f800
#define FUNC 0x0000003f
#define SYNC 0x0000000f
#define RDHWR 0x0000003b
/* microMIPS definitions */
#define MM_POOL32A_FUNC 0xfc00ffff
#define MM_RDHWR 0x00006b3c
#define MM_RS 0x001f0000
#define MM_RT 0x03e00000
/*
* The ll_bit is cleared by r*_switch.S
*/
unsigned int ll_bit;
struct task_struct *ll_task;
static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
{
unsigned long value, __user *vaddr;
long offset;
/*
* 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 __user *)
((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
if ((unsigned long)vaddr & 3)
return SIGBUS;
if (get_user(value, vaddr))
return SIGSEGV;
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;
return 0;
}
static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
{
unsigned long __user *vaddr;
unsigned long reg;
long offset;
/*
* 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 __user *)
((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
reg = (opcode & RT) >> 16;
if ((unsigned long)vaddr & 3)
return SIGBUS;
preempt_disable();
if (ll_bit == 0 || ll_task != current) {
regs->regs[reg] = 0;
preempt_enable();
return 0;
}
preempt_enable();
if (put_user(regs->regs[reg], vaddr))
return SIGSEGV;
regs->regs[reg] = 1;
return 0;
}
/*
* 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 int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
{
if ((opcode & OPCODE) == LL) {
perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
1, regs, 0);
return simulate_ll(regs, opcode);
}
if ((opcode & OPCODE) == SC) {
perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
1, regs, 0);
return simulate_sc(regs, opcode);
}
return -1; /* Must be something else ... */
}
/*
* Simulate trapping 'rdhwr' instructions to provide user accessible
* registers not implemented in hardware.
*/
static int simulate_rdhwr(struct pt_regs *regs, int rd, int rt)
{
struct thread_info *ti = task_thread_info(current);
perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
1, regs, 0);
switch (rd) {
case 0: /* CPU number */
regs->regs[rt] = smp_processor_id();
return 0;
case 1: /* SYNCI length */
regs->regs[rt] = min(current_cpu_data.dcache.linesz,
current_cpu_data.icache.linesz);
return 0;
case 2: /* Read count register */
regs->regs[rt] = read_c0_count();
return 0;
case 3: /* Count register resolution */
switch (current_cpu_type()) {
case CPU_20KC:
case CPU_25KF:
regs->regs[rt] = 1;
break;
default:
regs->regs[rt] = 2;
}
return 0;
case 29:
regs->regs[rt] = ti->tp_value;
return 0;
default:
return -1;
}
}
static int simulate_rdhwr_normal(struct pt_regs *regs, unsigned int opcode)
{
if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
int rd = (opcode & RD) >> 11;
int rt = (opcode & RT) >> 16;
simulate_rdhwr(regs, rd, rt);
return 0;
}
/* Not ours. */
return -1;
}
static int simulate_rdhwr_mm(struct pt_regs *regs, unsigned short opcode)
{
if ((opcode & MM_POOL32A_FUNC) == MM_RDHWR) {
int rd = (opcode & MM_RS) >> 16;
int rt = (opcode & MM_RT) >> 21;
simulate_rdhwr(regs, rd, rt);
return 0;
}
/* Not ours. */
return -1;
}
static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
{
if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC) {
perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
1, regs, 0);
return 0;
}
return -1; /* Must be something else ... */
}
asmlinkage void do_ov(struct pt_regs *regs)
{
enum ctx_state prev_state;
siginfo_t info;
prev_state = exception_enter();
die_if_kernel("Integer overflow", regs);
info.si_code = FPE_INTOVF;
info.si_signo = SIGFPE;
info.si_errno = 0;
info.si_addr = (void __user *) regs->cp0_epc;
force_sig_info(SIGFPE, &info, current);
exception_exit(prev_state);
}
int process_fpemu_return(int sig, void __user *fault_addr)
{
if (sig == SIGSEGV || sig == SIGBUS) {
struct siginfo si = {0};
si.si_addr = fault_addr;
si.si_signo = sig;
if (sig == SIGSEGV) {
down_read(&current->mm->mmap_sem);
if (find_vma(current->mm, (unsigned long)fault_addr))
si.si_code = SEGV_ACCERR;
else
si.si_code = SEGV_MAPERR;
up_read(&current->mm->mmap_sem);
} else {
si.si_code = BUS_ADRERR;
}
force_sig_info(sig, &si, current);
return 1;
} else if (sig) {
force_sig(sig, current);
return 1;
} else {
return 0;
}
}
/*
* XXX Delayed fp exceptions when doing a lazy ctx switch XXX
*/
asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
{
enum ctx_state prev_state;
siginfo_t info = {0};
prev_state = exception_enter();
if (notify_die(DIE_FP, "FP exception", regs, 0, regs_to_trapnr(regs),
SIGFPE) == NOTIFY_STOP)
goto out;
die_if_kernel("FP exception in kernel code", regs);
if (fcr31 & FPU_CSR_UNI_X) {
int sig;
void __user *fault_addr = NULL;
/*
* 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.
*/
/* Ensure 'resume' not overwrite saved fp context again. */
lose_fpu(1);
/* Run the emulator */
sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
&fault_addr);
/*
* We can't allow the emulated instruction to leave any of
* the cause bit set in $fcr31.
*/
current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
/* Restore the hardware register state */
own_fpu(1); /* Using the FPU again. */
/* If something went wrong, signal */
process_fpemu_return(sig, fault_addr);
goto out;
} else if (fcr31 & FPU_CSR_INV_X)
info.si_code = FPE_FLTINV;
else if (fcr31 & FPU_CSR_DIV_X)
info.si_code = FPE_FLTDIV;
else if (fcr31 & FPU_CSR_OVF_X)
info.si_code = FPE_FLTOVF;
else if (fcr31 & FPU_CSR_UDF_X)
info.si_code = FPE_FLTUND;
else if (fcr31 & FPU_CSR_INE_X)
info.si_code = FPE_FLTRES;
else
info.si_code = __SI_FAULT;
info.si_signo = SIGFPE;
info.si_errno = 0;
info.si_addr = (void __user *) regs->cp0_epc;
force_sig_info(SIGFPE, &info, current);
out:
exception_exit(prev_state);
}
static void do_trap_or_bp(struct pt_regs *regs, unsigned int code,
const char *str)
{
siginfo_t info;
char b[40];
#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
if (kgdb_ll_trap(DIE_TRAP, str, regs, code, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
return;
#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
if (notify_die(DIE_TRAP, str, regs, code, regs_to_trapnr(regs),
SIGTRAP) == NOTIFY_STOP)
return;
/*
* A short test says that IRIX 5.3 sends SIGTRAP for all trap
* insns, even for trap and break codes that indicate arithmetic
* failures. Weird ...
* But should we continue the brokenness??? --macro
*/
switch (code) {
case BRK_OVERFLOW:
case BRK_DIVZERO:
scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
die_if_kernel(b, regs);
if (code == 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 __user *) regs->cp0_epc;
force_sig_info(SIGFPE, &info, current);
break;
case BRK_BUG:
die_if_kernel("Kernel bug detected", regs);
force_sig(SIGTRAP, current);
break;
case BRK_MEMU:
/*
* Address errors may be deliberately induced by the FPU
* emulator to retake control of the CPU after executing the
* instruction in the delay slot of an emulated branch.
*
* Terminate if exception was recognized as a delay slot return
* otherwise handle as normal.
*/
if (do_dsemulret(regs))
return;
die_if_kernel("Math emu break/trap", regs);
force_sig(SIGTRAP, current);
break;
default:
scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
die_if_kernel(b, regs);
force_sig(SIGTRAP, current);
}
}
asmlinkage void do_bp(struct pt_regs *regs)
{
unsigned int opcode, bcode;
enum ctx_state prev_state;
unsigned long epc;
u16 instr[2];
mm_segment_t seg;
seg = get_fs();
if (!user_mode(regs))
set_fs(KERNEL_DS);
prev_state = exception_enter();
if (get_isa16_mode(regs->cp0_epc)) {
/* Calculate EPC. */
epc = exception_epc(regs);
if (cpu_has_mmips) {
if ((__get_user(instr[0], (u16 __user *)msk_isa16_mode(epc)) ||
(__get_user(instr[1], (u16 __user *)msk_isa16_mode(epc + 2)))))
goto out_sigsegv;
opcode = (instr[0] << 16) | instr[1];
} else {
/* MIPS16e mode */
if (__get_user(instr[0],
(u16 __user *)msk_isa16_mode(epc)))
goto out_sigsegv;
bcode = (instr[0] >> 6) & 0x3f;
do_trap_or_bp(regs, bcode, "Break");
goto out;
}
} else {
if (__get_user(opcode,
(unsigned int __user *) exception_epc(regs)))
goto out_sigsegv;
}
/*
* 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;
/*
* notify the kprobe handlers, if instruction is likely to
* pertain to them.
*/
switch (bcode) {
case BRK_KPROBE_BP:
if (notify_die(DIE_BREAK, "debug", regs, bcode,
regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
goto out;
else
break;
case BRK_KPROBE_SSTEPBP:
if (notify_die(DIE_SSTEPBP, "single_step", regs, bcode,
regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
goto out;
else
break;
default:
break;
}
do_trap_or_bp(regs, bcode, "Break");
out:
set_fs(seg);
exception_exit(prev_state);
return;
out_sigsegv:
force_sig(SIGSEGV, current);
goto out;
}
asmlinkage void do_tr(struct pt_regs *regs)
{
u32 opcode, tcode = 0;
enum ctx_state prev_state;
u16 instr[2];
mm_segment_t seg;
unsigned long epc = msk_isa16_mode(exception_epc(regs));
seg = get_fs();
if (!user_mode(regs))
set_fs(get_ds());
prev_state = exception_enter();
if (get_isa16_mode(regs->cp0_epc)) {
if (__get_user(instr[0], (u16 __user *)(epc + 0)) ||
__get_user(instr[1], (u16 __user *)(epc + 2)))
goto out_sigsegv;
opcode = (instr[0] << 16) | instr[1];
/* Immediate versions don't provide a code. */
if (!(opcode & OPCODE))
tcode = (opcode >> 12) & ((1 << 4) - 1);
} else {
if (__get_user(opcode, (u32 __user *)epc))
goto out_sigsegv;
/* Immediate versions don't provide a code. */
if (!(opcode & OPCODE))
tcode = (opcode >> 6) & ((1 << 10) - 1);
}
do_trap_or_bp(regs, tcode, "Trap");
out:
set_fs(seg);
exception_exit(prev_state);
return;
out_sigsegv:
force_sig(SIGSEGV, current);
goto out;
}
asmlinkage void do_ri(struct pt_regs *regs)
{
unsigned int __user *epc = (unsigned int __user *)exception_epc(regs);
unsigned long old_epc = regs->cp0_epc;
unsigned long old31 = regs->regs[31];
enum ctx_state prev_state;
unsigned int opcode = 0;
int status = -1;
prev_state = exception_enter();
if (notify_die(DIE_RI, "RI Fault", regs, 0, regs_to_trapnr(regs),
SIGILL) == NOTIFY_STOP)
goto out;
die_if_kernel("Reserved instruction in kernel code", regs);
if (unlikely(compute_return_epc(regs) < 0))
goto out;
if (get_isa16_mode(regs->cp0_epc)) {
unsigned short mmop[2] = { 0 };
if (unlikely(get_user(mmop[0], epc) < 0))
status = SIGSEGV;
if (unlikely(get_user(mmop[1], epc) < 0))
status = SIGSEGV;
opcode = (mmop[0] << 16) | mmop[1];
if (status < 0)
status = simulate_rdhwr_mm(regs, opcode);
} else {
if (unlikely(get_user(opcode, epc) < 0))
status = SIGSEGV;
if (!cpu_has_llsc && status < 0)
status = simulate_llsc(regs, opcode);
if (status < 0)
status = simulate_rdhwr_normal(regs, opcode);
if (status < 0)
status = simulate_sync(regs, opcode);
}
if (status < 0)
status = SIGILL;
if (unlikely(status > 0)) {
regs->cp0_epc = old_epc; /* Undo skip-over. */
regs->regs[31] = old31;
force_sig(status, current);
}
out:
exception_exit(prev_state);
}
/*
* MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
* emulated more than some threshold number of instructions, force migration to
* a "CPU" that has FP support.
*/
static void mt_ase_fp_affinity(void)
{
#ifdef CONFIG_MIPS_MT_FPAFF
if (mt_fpemul_threshold > 0 &&
((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
/*
* If there's no FPU present, or if the application has already
* restricted the allowed set to exclude any CPUs with FPUs,
* we'll skip the procedure.
*/
if (cpus_intersects(current->cpus_allowed, mt_fpu_cpumask)) {
cpumask_t tmask;
current->thread.user_cpus_allowed
= current->cpus_allowed;
cpus_and(tmask, current->cpus_allowed,
mt_fpu_cpumask);
set_cpus_allowed_ptr(current, &tmask);
set_thread_flag(TIF_FPUBOUND);
}
}
#endif /* CONFIG_MIPS_MT_FPAFF */
}
/*
* No lock; only written during early bootup by CPU 0.
*/
static RAW_NOTIFIER_HEAD(cu2_chain);
int __ref register_cu2_notifier(struct notifier_block *nb)
{
return raw_notifier_chain_register(&cu2_chain, nb);
}
int cu2_notifier_call_chain(unsigned long val, void *v)
{
return raw_notifier_call_chain(&cu2_chain, val, v);
}
static int default_cu2_call(struct notifier_block *nfb, unsigned long action,
void *data)
{
struct pt_regs *regs = data;
die_if_kernel("COP2: Unhandled kernel unaligned access or invalid "
"instruction", regs);
force_sig(SIGILL, current);
return NOTIFY_OK;
}
static int enable_restore_fp_context(int msa)
{
int err, was_fpu_owner, prior_msa;
if (!used_math()) {
/* First time FP context user. */
err = init_fpu();
if (msa && !err) {
enable_msa();
_init_msa_upper();
set_thread_flag(TIF_USEDMSA);
set_thread_flag(TIF_MSA_CTX_LIVE);
}
if (!err)
set_used_math();
return err;
}
/*
* This task has formerly used the FP context.
*
* If this thread has no live MSA vector context then we can simply
* restore the scalar FP context. If it has live MSA vector context
* (that is, it has or may have used MSA since last performing a
* function call) then we'll need to restore the vector context. This
* applies even if we're currently only executing a scalar FP
* instruction. This is because if we were to later execute an MSA
* instruction then we'd either have to:
*
* - Restore the vector context & clobber any registers modified by
* scalar FP instructions between now & then.
*
* or
*
* - Not restore the vector context & lose the most significant bits
* of all vector registers.
*
* Neither of those options is acceptable. We cannot restore the least
* significant bits of the registers now & only restore the most
* significant bits later because the most significant bits of any
* vector registers whose aliased FP register is modified now will have
* been zeroed. We'd have no way to know that when restoring the vector
* context & thus may load an outdated value for the most significant
* bits of a vector register.
*/
if (!msa && !thread_msa_context_live())
return own_fpu(1);
/*
* This task is using or has previously used MSA. Thus we require
* that Status.FR == 1.
*/
was_fpu_owner = is_fpu_owner();
err = own_fpu(0);
if (err)
return err;
enable_msa();
write_msa_csr(current->thread.fpu.msacsr);
set_thread_flag(TIF_USEDMSA);
/*
* If this is the first time that the task is using MSA and it has
* previously used scalar FP in this time slice then we already nave
* FP context which we shouldn't clobber. We do however need to clear
* the upper 64b of each vector register so that this task has no
* opportunity to see data left behind by another.
*/
prior_msa = test_and_set_thread_flag(TIF_MSA_CTX_LIVE);
if (!prior_msa && was_fpu_owner) {
_init_msa_upper();
return 0;
}
if (!prior_msa) {
/*
* Restore the least significant 64b of each vector register
* from the existing scalar FP context.
*/
_restore_fp(current);
/*
* The task has not formerly used MSA, so clear the upper 64b
* of each vector register such that it cannot see data left
* behind by another task.
*/
_init_msa_upper();
} else {
/* We need to restore the vector context. */
restore_msa(current);
/* Restore the scalar FP control & status register */
if (!was_fpu_owner)
asm volatile("ctc1 %0, $31" : : "r"(current->thread.fpu.fcr31));
}
return 0;
}
asmlinkage void do_cpu(struct pt_regs *regs)
{
enum ctx_state prev_state;
unsigned int __user *epc;
unsigned long old_epc, old31;
unsigned int opcode;
unsigned int cpid;
int status, err;
unsigned long __maybe_unused flags;
prev_state = exception_enter();
cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
if (cpid != 2)
die_if_kernel("do_cpu invoked from kernel context!", regs);
switch (cpid) {
case 0:
epc = (unsigned int __user *)exception_epc(regs);
old_epc = regs->cp0_epc;
old31 = regs->regs[31];
opcode = 0;
status = -1;
if (unlikely(compute_return_epc(regs) < 0))
goto out;
if (get_isa16_mode(regs->cp0_epc)) {
unsigned short mmop[2] = { 0 };
if (unlikely(get_user(mmop[0], epc) < 0))
status = SIGSEGV;
if (unlikely(get_user(mmop[1], epc) < 0))
status = SIGSEGV;
opcode = (mmop[0] << 16) | mmop[1];
if (status < 0)
status = simulate_rdhwr_mm(regs, opcode);
} else {
if (unlikely(get_user(opcode, epc) < 0))
status = SIGSEGV;
if (!cpu_has_llsc && status < 0)
status = simulate_llsc(regs, opcode);
if (status < 0)
status = simulate_rdhwr_normal(regs, opcode);
}
if (status < 0)
status = SIGILL;
if (unlikely(status > 0)) {
regs->cp0_epc = old_epc; /* Undo skip-over. */
regs->regs[31] = old31;
force_sig(status, current);
}
goto out;
case 3:
/*
* Old (MIPS I and MIPS II) processors will set this code
* for COP1X opcode instructions that replaced the original
* COP3 space. We don't limit COP1 space instructions in
* the emulator according to the CPU ISA, so we want to
* treat COP1X instructions consistently regardless of which
* code the CPU chose. Therefore we redirect this trap to
* the FP emulator too.
*
* Then some newer FPU-less processors use this code
* erroneously too, so they are covered by this choice
* as well.
*/
if (raw_cpu_has_fpu)
break;
/* Fall through. */
case 1:
err = enable_restore_fp_context(0);
if (!raw_cpu_has_fpu || err) {
int sig;
void __user *fault_addr = NULL;
sig = fpu_emulator_cop1Handler(regs,
&current->thread.fpu,
0, &fault_addr);
if (!process_fpemu_return(sig, fault_addr) && !err)
mt_ase_fp_affinity();
}
goto out;
case 2:
raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs);
goto out;
}
force_sig(SIGILL, current);
out:
exception_exit(prev_state);
}
asmlinkage void do_msa_fpe(struct pt_regs *regs)
{
enum ctx_state prev_state;
prev_state = exception_enter();
die_if_kernel("do_msa_fpe invoked from kernel context!", regs);
force_sig(SIGFPE, current);
exception_exit(prev_state);
}
asmlinkage void do_msa(struct pt_regs *regs)
{
enum ctx_state prev_state;
int err;
prev_state = exception_enter();
if (!cpu_has_msa || test_thread_flag(TIF_32BIT_FPREGS)) {
force_sig(SIGILL, current);
goto out;
}
die_if_kernel("do_msa invoked from kernel context!", regs);
err = enable_restore_fp_context(1);
if (err)
force_sig(SIGILL, current);
out:
exception_exit(prev_state);
}
asmlinkage void do_mdmx(struct pt_regs *regs)
{
enum ctx_state prev_state;
prev_state = exception_enter();
force_sig(SIGILL, current);
exception_exit(prev_state);
}
/*
* Called with interrupts disabled.
*/
asmlinkage void do_watch(struct pt_regs *regs)
{
enum ctx_state prev_state;
u32 cause;
prev_state = exception_enter();
/*
* Clear WP (bit 22) bit of cause register so we don't loop
* forever.
*/
cause = read_c0_cause();
cause &= ~(1 << 22);
write_c0_cause(cause);
/*
* If the current thread has the watch registers loaded, save
* their values and send SIGTRAP. Otherwise another thread
* left the registers set, clear them and continue.
*/
if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {
mips_read_watch_registers();
local_irq_enable();
force_sig(SIGTRAP, current);
} else {
mips_clear_watch_registers();
local_irq_enable();
}
exception_exit(prev_state);
}
asmlinkage void do_mcheck(struct pt_regs *regs)
{
const int field = 2 * sizeof(unsigned long);
int multi_match = regs->cp0_status & ST0_TS;
enum ctx_state prev_state;
prev_state = exception_enter();
show_regs(regs);
if (multi_match) {
printk("Index : %0x\n", read_c0_index());
printk("Pagemask: %0x\n", read_c0_pagemask());
printk("EntryHi : %0*lx\n", field, read_c0_entryhi());
printk("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
printk("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
printk("\n");
dump_tlb_all();
}
show_code((unsigned int __user *) regs->cp0_epc);
/*
* 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.",
(multi_match) ? "" : "not ");
}
asmlinkage void do_mt(struct pt_regs *regs)
{
int subcode;
subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
>> VPECONTROL_EXCPT_SHIFT;
switch (subcode) {
case 0:
printk(KERN_DEBUG "Thread Underflow\n");
break;
case 1:
printk(KERN_DEBUG "Thread Overflow\n");
break;
case 2:
printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
break;
case 3:
printk(KERN_DEBUG "Gating Storage Exception\n");
break;
case 4:
printk(KERN_DEBUG "YIELD Scheduler Exception\n");
break;
case 5:
printk(KERN_DEBUG "Gating Storage Scheduler Exception\n");
break;
default:
printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
subcode);
break;
}
die_if_kernel("MIPS MT Thread exception in kernel", regs);
force_sig(SIGILL, current);
}
asmlinkage void do_dsp(struct pt_regs *regs)
{
if (cpu_has_dsp)
panic("Unexpected DSP exception");
force_sig(SIGILL, current);
}
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);
}
static int __initdata l1parity = 1;
static int __init nol1parity(char *s)
{
l1parity = 0;
return 1;
}
__setup("nol1par", nol1parity);
static int __initdata l2parity = 1;
static int __init nol2parity(char *s)
{
l2parity = 0;
return 1;
}
__setup("nol2par", nol2parity);
/*
* 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_type()) {
case CPU_24K:
case CPU_34K:
case CPU_74K:
case CPU_1004K:
case CPU_1074K:
case CPU_INTERAPTIV:
case CPU_PROAPTIV:
case CPU_P5600:
{
#define ERRCTL_PE 0x80000000
#define ERRCTL_L2P 0x00800000
unsigned long errctl;
unsigned int l1parity_present, l2parity_present;
errctl = read_c0_ecc();
errctl &= ~(ERRCTL_PE|ERRCTL_L2P);
/* probe L1 parity support */
write_c0_ecc(errctl | ERRCTL_PE);
back_to_back_c0_hazard();
l1parity_present = (read_c0_ecc() & ERRCTL_PE);
/* probe L2 parity support */
write_c0_ecc(errctl|ERRCTL_L2P);
back_to_back_c0_hazard();
l2parity_present = (read_c0_ecc() & ERRCTL_L2P);
if (l1parity_present && l2parity_present) {
if (l1parity)
errctl |= ERRCTL_PE;
if (l1parity ^ l2parity)
errctl |= ERRCTL_L2P;
} else if (l1parity_present) {
if (l1parity)
errctl |= ERRCTL_PE;
} else if (l2parity_present) {
if (l2parity)
errctl |= ERRCTL_L2P;
} else {
/* No parity available */
}
printk(KERN_INFO "Writing ErrCtl register=%08lx\n", errctl);
write_c0_ecc(errctl);
back_to_back_c0_hazard();
errctl = read_c0_ecc();
printk(KERN_INFO "Readback ErrCtl register=%08lx\n", errctl);
if (l1parity_present)
printk(KERN_INFO "Cache parity protection %sabled\n",
(errctl & ERRCTL_PE) ? "en" : "dis");
if (l2parity_present) {
if (l1parity_present && l1parity)
errctl ^= ERRCTL_L2P;
printk(KERN_INFO "L2 cache parity protection %sabled\n",
(errctl & ERRCTL_L2P) ? "en" : "dis");
}
}
break;
case CPU_5KC:
case CPU_5KE:
case CPU_LOONGSON1:
write_c0_ecc(0x80000000);
back_to_back_c0_hazard();
/* Set the PE bit (bit 31) in the c0_errctl register. */
printk(KERN_INFO "Cache parity protection %sabled\n",
(read_c0_ecc() & 0x80000000) ? "en" : "dis");
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");
if (cpu_has_mips_r2 &&
((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS)) {
pr_err("Error bits: %s%s%s%s%s%s%s%s\n",
reg_val & (1<<29) ? "ED " : "",
reg_val & (1<<28) ? "ET " : "",
reg_val & (1<<27) ? "ES " : "",
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 " : "");
} else {
pr_err("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!");
}
asmlinkage void do_ftlb(void)
{
const int field = 2 * sizeof(unsigned long);
unsigned int reg_val;
/* For the moment, report the problem and hang. */
if (cpu_has_mips_r2 &&
((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS)) {
pr_err("FTLB error exception, cp0_ecc=0x%08x:\n",
read_c0_ecc());
pr_err("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
reg_val = read_c0_cacheerr();
pr_err("c0_cacheerr == %08x\n", reg_val);
if ((reg_val & 0xc0000000) == 0xc0000000) {
pr_err("Decoded c0_cacheerr: FTLB parity error\n");
} else {
pr_err("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
reg_val & (1<<30) ? "secondary" : "primary",
reg_val & (1<<31) ? "data" : "insn");
}
} else {
pr_err("FTLB error exception\n");
}
/* Just print the cacheerr bits for now */
cache_parity_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, old_ra;
unsigned int debug;
printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
depc = read_c0_depc();
debug = read_c0_debug();
printk(KERN_DEBUG "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;
old_ra = regs->regs[31];
regs->cp0_epc = depc;
compute_return_epc(regs);
depc = regs->cp0_epc;
regs->cp0_epc = old_epc;
regs->regs[31] = old_ra;
} else
depc += 4;
write_c0_depc(depc);
#if 0
printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
write_c0_debug(debug | 0x100);
#endif
}
/*
* NMI exception handler.
* No lock; only written during early bootup by CPU 0.
*/
static RAW_NOTIFIER_HEAD(nmi_chain);
int register_nmi_notifier(struct notifier_block *nb)
{
return raw_notifier_chain_register(&nmi_chain, nb);
}
void __noreturn nmi_exception_handler(struct pt_regs *regs)
{
char str[100];
raw_notifier_call_chain(&nmi_chain, 0, regs);
bust_spinlocks(1);
snprintf(str, 100, "CPU%d NMI taken, CP0_EPC=%lx\n",
smp_processor_id(), regs->cp0_epc);
regs->cp0_epc = read_c0_errorepc();
die(str, regs);
}
#define VECTORSPACING 0x100 /* for EI/VI mode */
unsigned long ebase;
unsigned long exception_handlers[32];
unsigned long vi_handlers[64];
void __init *set_except_vector(int n, void *addr)
{
unsigned long handler = (unsigned long) addr;
unsigned long old_handler;
#ifdef CONFIG_CPU_MICROMIPS
/*
* Only the TLB handlers are cache aligned with an even
* address. All other handlers are on an odd address and
* require no modification. Otherwise, MIPS32 mode will
* be entered when handling any TLB exceptions. That
* would be bad...since we must stay in microMIPS mode.
*/
if (!(handler & 0x1))
handler |= 1;
#endif
old_handler = xchg(&exception_handlers[n], handler);
if (n == 0 && cpu_has_divec) {
#ifdef CONFIG_CPU_MICROMIPS
unsigned long jump_mask = ~((1 << 27) - 1);
#else
unsigned long jump_mask = ~((1 << 28) - 1);
#endif
u32 *buf = (u32 *)(ebase + 0x200);
unsigned int k0 = 26;
if ((handler & jump_mask) == ((ebase + 0x200) & jump_mask)) {
uasm_i_j(&buf, handler & ~jump_mask);
uasm_i_nop(&buf);
} else {
UASM_i_LA(&buf, k0, handler);
uasm_i_jr(&buf, k0);
uasm_i_nop(&buf);
}
local_flush_icache_range(ebase + 0x200, (unsigned long)buf);
}
return (void *)old_handler;
}
static void do_default_vi(void)
{
show_regs(get_irq_regs());
panic("Caught unexpected vectored interrupt.");
}
static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
{
unsigned long handler;
unsigned long old_handler = vi_handlers[n];
int srssets = current_cpu_data.srsets;
u16 *h;
unsigned char *b;
BUG_ON(!cpu_has_veic && !cpu_has_vint);
if (addr == NULL) {
handler = (unsigned long) do_default_vi;
srs = 0;
} else
handler = (unsigned long) addr;
vi_handlers[n] = handler;
b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
if (srs >= srssets)
panic("Shadow register set %d not supported", srs);
if (cpu_has_veic) {
if (board_bind_eic_interrupt)
board_bind_eic_interrupt(n, srs);
} else if (cpu_has_vint) {
/* SRSMap is only defined if shadow sets are implemented */
if (srssets > 1)
change_c0_srsmap(0xf << n*4, srs << n*4);
}
if (srs == 0) {
/*
* If no shadow set is selected then use the default handler
* that does normal register saving and standard interrupt exit
*/
extern char except_vec_vi, except_vec_vi_lui;
extern char except_vec_vi_ori, except_vec_vi_end;
extern char rollback_except_vec_vi;
char *vec_start = using_rollback_handler() ?
&rollback_except_vec_vi : &except_vec_vi;
#if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_BIG_ENDIAN)
const int lui_offset = &except_vec_vi_lui - vec_start + 2;
const int ori_offset = &except_vec_vi_ori - vec_start + 2;
#else
const int lui_offset = &except_vec_vi_lui - vec_start;
const int ori_offset = &except_vec_vi_ori - vec_start;
#endif
const int handler_len = &except_vec_vi_end - vec_start;
if (handler_len > VECTORSPACING) {
/*
* Sigh... panicing won't help as the console
* is probably not configured :(
*/
panic("VECTORSPACING too small");
}
set_handler(((unsigned long)b - ebase), vec_start,
#ifdef CONFIG_CPU_MICROMIPS
(handler_len - 1));
#else
handler_len);
#endif
h = (u16 *)(b + lui_offset);
*h = (handler >> 16) & 0xffff;
h = (u16 *)(b + ori_offset);
*h = (handler & 0xffff);
local_flush_icache_range((unsigned long)b,
(unsigned long)(b+handler_len));
}
else {
/*
* In other cases jump directly to the interrupt handler. It
* is the handler's responsibility to save registers if required
* (eg hi/lo) and return from the exception using "eret".
*/
u32 insn;
h = (u16 *)b;
/* j handler */
#ifdef CONFIG_CPU_MICROMIPS
insn = 0xd4000000 | (((u32)handler & 0x07ffffff) >> 1);
#else
insn = 0x08000000 | (((u32)handler & 0x0fffffff) >> 2);
#endif
h[0] = (insn >> 16) & 0xffff;
h[1] = insn & 0xffff;
h[2] = 0;
h[3] = 0;
local_flush_icache_range((unsigned long)b,
(unsigned long)(b+8));
}
return (void *)old_handler;
}
void *set_vi_handler(int n, vi_handler_t addr)
{
return set_vi_srs_handler(n, addr, 0);
}
extern void tlb_init(void);
/*
* Timer interrupt
*/
int cp0_compare_irq;
EXPORT_SYMBOL_GPL(cp0_compare_irq);
int cp0_compare_irq_shift;
/*
* Performance counter IRQ or -1 if shared with timer
*/
int cp0_perfcount_irq;
EXPORT_SYMBOL_GPL(cp0_perfcount_irq);
static int noulri;
static int __init ulri_disable(char *s)
{
pr_info("Disabling ulri\n");
noulri = 1;
return 1;
}
__setup("noulri", ulri_disable);
/* configure STATUS register */
static void configure_status(void)
{
/*
* 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.
*/
unsigned int status_set = ST0_CU0;
#ifdef CONFIG_64BIT
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;
if (cpu_has_dsp)
status_set |= ST0_MX;
change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
status_set);
}
/* configure HWRENA register */
static void configure_hwrena(void)
{
unsigned int hwrena = cpu_hwrena_impl_bits;
if (cpu_has_mips_r2)
hwrena |= 0x0000000f;
if (!noulri && cpu_has_userlocal)
hwrena |= (1 << 29);
if (hwrena)
write_c0_hwrena(hwrena);
}
static void configure_exception_vector(void)
{
if (cpu_has_veic || cpu_has_vint) {
unsigned long sr = set_c0_status(ST0_BEV);
write_c0_ebase(ebase);
write_c0_status(sr);
/* Setting vector spacing enables EI/VI mode */
change_c0_intctl(0x3e0, VECTORSPACING);
}
if (cpu_has_divec) {
if (cpu_has_mipsmt) {
unsigned int vpflags = dvpe();
set_c0_cause(CAUSEF_IV);
evpe(vpflags);
} else
set_c0_cause(CAUSEF_IV);
}
}
void per_cpu_trap_init(bool is_boot_cpu)
{
unsigned int cpu = smp_processor_id();
configure_status();
configure_hwrena();
configure_exception_vector();
/*
* Before R2 both interrupt numbers were fixed to 7, so on R2 only:
*
* o read IntCtl.IPTI to determine the timer interrupt
* o read IntCtl.IPPCI to determine the performance counter interrupt
*/
if (cpu_has_mips_r2) {
cp0_compare_irq_shift = CAUSEB_TI - CAUSEB_IP;
cp0_compare_irq = (read_c0_intctl() >> INTCTLB_IPTI) & 7;
cp0_perfcount_irq = (read_c0_intctl() >> INTCTLB_IPPCI) & 7;
if (cp0_perfcount_irq == cp0_compare_irq)
cp0_perfcount_irq = -1;
} else {
cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
cp0_compare_irq_shift = CP0_LEGACY_PERFCNT_IRQ;
cp0_perfcount_irq = -1;
}
if (!cpu_data[cpu].asid_cache)
cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
atomic_inc(&init_mm.mm_count);
current->active_mm = &init_mm;
BUG_ON(current->mm);
enter_lazy_tlb(&init_mm, current);
/* Boot CPU's cache setup in setup_arch(). */
if (!is_boot_cpu)
cpu_cache_init();
tlb_init();
TLBMISS_HANDLER_SETUP();
}
/* Install CPU exception handler */
void set_handler(unsigned long offset, void *addr, unsigned long size)
{
#ifdef CONFIG_CPU_MICROMIPS
memcpy((void *)(ebase + offset), ((unsigned char *)addr - 1), size);
#else
memcpy((void *)(ebase + offset), addr, size);
#endif
local_flush_icache_range(ebase + offset, ebase + offset + size);
}
static char panic_null_cerr[] =
"Trying to set NULL cache error exception handler";
/*
* Install uncached CPU exception handler.
* This is suitable only for the cache error exception which is the only
* exception handler that is being run uncached.
*/
void set_uncached_handler(unsigned long offset, void *addr,
unsigned long size)
{
unsigned long uncached_ebase = CKSEG1ADDR(ebase);
if (!addr)
panic(panic_null_cerr);
memcpy((void *)(uncached_ebase + offset), addr, size);
}
static int __initdata rdhwr_noopt;
static int __init set_rdhwr_noopt(char *str)
{
rdhwr_noopt = 1;
return 1;
}
__setup("rdhwr_noopt", set_rdhwr_noopt);
void __init trap_init(void)
{
extern char except_vec3_generic;
extern char except_vec4;
extern char except_vec3_r4000;
unsigned long i;
check_wait();
#if defined(CONFIG_KGDB)
if (kgdb_early_setup)
return; /* Already done */
#endif
if (cpu_has_veic || cpu_has_vint) {
unsigned long size = 0x200 + VECTORSPACING*64;
ebase = (unsigned long)
__alloc_bootmem(size, 1 << fls(size), 0);
} else {
#ifdef CONFIG_KVM_GUEST
#define KVM_GUEST_KSEG0 0x40000000
ebase = KVM_GUEST_KSEG0;
#else
ebase = CKSEG0;
#endif
if (cpu_has_mips_r2)
ebase += (read_c0_ebase() & 0x3ffff000);
}
if (cpu_has_mmips) {
unsigned int config3 = read_c0_config3();
if (IS_ENABLED(CONFIG_CPU_MICROMIPS))
write_c0_config3(config3 | MIPS_CONF3_ISA_OE);
else
write_c0_config3(config3 & ~MIPS_CONF3_ISA_OE);
}
if (board_ebase_setup)
board_ebase_setup();
per_cpu_trap_init(true);
/*
* Copy the generic exception handlers to their final destination.
* This will be overriden later as suitable for a particular
* configuration.
*/
set_handler(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 && board_ejtag_handler_setup)
board_ejtag_handler_setup();
/*
* Only some CPUs have the watch exceptions.
*/
if (cpu_has_watch)
set_except_vector(23, handle_watch);
/*
* Initialise interrupt handlers
*/
if (cpu_has_veic || cpu_has_vint) {
int nvec = cpu_has_veic ? 64 : 8;
for (i = 0; i < nvec; i++)
set_vi_handler(i, NULL);
}
else if (cpu_has_divec)
set_handler(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(0, using_rollback_handler() ? rollback_handle_int
: handle_int);
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, rdhwr_noopt ? handle_ri :
(cpu_has_vtag_icache ?
handle_ri_rdhwr_vivt : handle_ri_rdhwr));
set_except_vector(11, handle_cpu);
set_except_vector(12, handle_ov);
set_except_vector(13, handle_tr);
set_except_vector(14, handle_msa_fpe);
if (current_cpu_type() == CPU_R6000 ||
current_cpu_type() == 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);
}
if (board_nmi_handler_setup)
board_nmi_handler_setup();
if (cpu_has_fpu && !cpu_has_nofpuex)
set_except_vector(15, handle_fpe);
set_except_vector(16, handle_ftlb);
if (cpu_has_rixiex) {
set_except_vector(19, tlb_do_page_fault_0);
set_except_vector(20, tlb_do_page_fault_0);
}
set_except_vector(21, handle_msa);
set_except_vector(22, handle_mdmx);
if (cpu_has_mcheck)
set_except_vector(24, handle_mcheck);
if (cpu_has_mipsmt)
set_except_vector(25, handle_mt);
set_except_vector(26, handle_dsp);
if (board_cache_error_setup)
board_cache_error_setup();
if (cpu_has_vce)
/* Special exception: R4[04]00 uses also the divec space. */
set_handler(0x180, &except_vec3_r4000, 0x100);
else if (cpu_has_4kex)
set_handler(0x180, &except_vec3_generic, 0x80);
else
set_handler(0x080, &except_vec3_generic, 0x80);
local_flush_icache_range(ebase, ebase + 0x400);
sort_extable(__start___dbe_table, __stop___dbe_table);
cu2_notifier(default_cu2_call, 0x80000000); /* Run last */
}
static int trap_pm_notifier(struct notifier_block *self, unsigned long cmd,
void *v)
{
switch (cmd) {
case CPU_PM_ENTER_FAILED:
case CPU_PM_EXIT:
configure_status();
configure_hwrena();
configure_exception_vector();
/* Restore register with CPU number for TLB handlers */
TLBMISS_HANDLER_RESTORE();
break;
}
return NOTIFY_OK;
}
static struct notifier_block trap_pm_notifier_block = {
.notifier_call = trap_pm_notifier,
};
static int __init trap_pm_init(void)
{
return cpu_pm_register_notifier(&trap_pm_notifier_block);
}
arch_initcall(trap_pm_init);
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