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linux-stable/arch/loongarch/kernel/traps.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Author: Huacai Chen <chenhuacai@loongson.cn>
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*/
#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/bug.h>
#include <linux/compiler.h>
#include <linux/context_tracking.h>
#include <linux/entry-common.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/kexec.h>
#include <linux/module.h>
#include <linux/extable.h>
#include <linux/mm.h>
#include <linux/sched/mm.h>
#include <linux/sched/debug.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
#include <linux/kallsyms.h>
#include <linux/memblock.h>
#include <linux/interrupt.h>
#include <linux/ptrace.h>
#include <linux/kgdb.h>
#include <linux/kdebug.h>
#include <linux/notifier.h>
#include <linux/irq.h>
#include <linux/perf_event.h>
#include <asm/addrspace.h>
#include <asm/bootinfo.h>
#include <asm/branch.h>
#include <asm/break.h>
#include <asm/cpu.h>
#include <asm/exception.h>
#include <asm/fpu.h>
#include <asm/lbt.h>
#include <asm/inst.h>
#include <asm/kgdb.h>
#include <asm/loongarch.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/ptrace.h>
#include <asm/sections.h>
#include <asm/siginfo.h>
#include <asm/stacktrace.h>
#include <asm/tlb.h>
#include <asm/types.h>
#include <asm/unwind.h>
#include <asm/uprobes.h>
#include "access-helper.h"
void *exception_table[EXCCODE_INT_START] = {
[0 ... EXCCODE_INT_START - 1] = handle_reserved,
[EXCCODE_TLBI] = handle_tlb_load,
[EXCCODE_TLBL] = handle_tlb_load,
[EXCCODE_TLBS] = handle_tlb_store,
[EXCCODE_TLBM] = handle_tlb_modify,
[EXCCODE_TLBNR] = handle_tlb_protect,
[EXCCODE_TLBNX] = handle_tlb_protect,
[EXCCODE_TLBPE] = handle_tlb_protect,
[EXCCODE_ADE] = handle_ade,
[EXCCODE_ALE] = handle_ale,
[EXCCODE_BCE] = handle_bce,
[EXCCODE_SYS] = handle_sys,
[EXCCODE_BP] = handle_bp,
[EXCCODE_INE] = handle_ri,
[EXCCODE_IPE] = handle_ri,
[EXCCODE_FPDIS] = handle_fpu,
[EXCCODE_LSXDIS] = handle_lsx,
[EXCCODE_LASXDIS] = handle_lasx,
[EXCCODE_FPE] = handle_fpe,
[EXCCODE_WATCH] = handle_watch,
[EXCCODE_BTDIS] = handle_lbt,
};
EXPORT_SYMBOL_GPL(exception_table);
static void show_backtrace(struct task_struct *task, const struct pt_regs *regs,
const char *loglvl, bool user)
{
unsigned long addr;
struct unwind_state state;
struct pt_regs *pregs = (struct pt_regs *)regs;
if (!task)
task = current;
printk("%sCall Trace:", loglvl);
for (unwind_start(&state, task, pregs);
!unwind_done(&state); unwind_next_frame(&state)) {
addr = unwind_get_return_address(&state);
print_ip_sym(loglvl, addr);
}
printk("%s\n", loglvl);
}
static void show_stacktrace(struct task_struct *task,
const struct pt_regs *regs, const char *loglvl, bool user)
{
int i;
const int field = 2 * sizeof(unsigned long);
unsigned long stackdata;
unsigned long *sp = (unsigned long *)regs->regs[3];
printk("%sStack :", loglvl);
i = 0;
while ((unsigned long) sp & (PAGE_SIZE - 1)) {
if (i && ((i % (64 / field)) == 0)) {
pr_cont("\n");
printk("%s ", loglvl);
}
if (i > 39) {
pr_cont(" ...");
break;
}
if (__get_addr(&stackdata, sp++, user)) {
pr_cont(" (Bad stack address)");
break;
}
pr_cont(" %0*lx", field, stackdata);
i++;
}
pr_cont("\n");
show_backtrace(task, regs, loglvl, user);
}
void show_stack(struct task_struct *task, unsigned long *sp, const char *loglvl)
{
struct pt_regs regs;
regs.csr_crmd = 0;
if (sp) {
regs.csr_era = 0;
regs.regs[1] = 0;
regs.regs[3] = (unsigned long)sp;
} else {
if (!task || task == current)
prepare_frametrace(&regs);
else {
regs.csr_era = task->thread.reg01;
regs.regs[1] = 0;
regs.regs[3] = task->thread.reg03;
regs.regs[22] = task->thread.reg22;
}
}
show_stacktrace(task, &regs, loglvl, false);
}
static void show_code(unsigned int *pc, bool user)
{
long i;
unsigned int insn;
printk("Code:");
for(i = -3 ; i < 6 ; i++) {
if (__get_inst(&insn, pc + i, user)) {
pr_cont(" (Bad address in era)\n");
break;
}
pr_cont("%c%08x%c", (i?' ':'<'), insn, (i?' ':'>'));
}
pr_cont("\n");
}
static void print_bool_fragment(const char *key, unsigned long val, bool first)
{
/* e.g. "+PG", "-DA" */
pr_cont("%s%c%s", first ? "" : " ", val ? '+' : '-', key);
}
static void print_plv_fragment(const char *key, int val)
{
/* e.g. "PLV0", "PPLV3" */
pr_cont("%s%d", key, val);
}
static void print_memory_type_fragment(const char *key, unsigned long val)
{
const char *humanized_type;
switch (val) {
case 0:
humanized_type = "SUC";
break;
case 1:
humanized_type = "CC";
break;
case 2:
humanized_type = "WUC";
break;
default:
pr_cont(" %s=Reserved(%lu)", key, val);
return;
}
/* e.g. " DATM=WUC" */
pr_cont(" %s=%s", key, humanized_type);
}
static void print_intr_fragment(const char *key, unsigned long val)
{
/* e.g. "LIE=0-1,3,5-7" */
pr_cont("%s=%*pbl", key, EXCCODE_INT_NUM, &val);
}
static void print_crmd(unsigned long x)
{
printk(" CRMD: %08lx (", x);
print_plv_fragment("PLV", (int) FIELD_GET(CSR_CRMD_PLV, x));
print_bool_fragment("IE", FIELD_GET(CSR_CRMD_IE, x), false);
print_bool_fragment("DA", FIELD_GET(CSR_CRMD_DA, x), false);
print_bool_fragment("PG", FIELD_GET(CSR_CRMD_PG, x), false);
print_memory_type_fragment("DACF", FIELD_GET(CSR_CRMD_DACF, x));
print_memory_type_fragment("DACM", FIELD_GET(CSR_CRMD_DACM, x));
print_bool_fragment("WE", FIELD_GET(CSR_CRMD_WE, x), false);
pr_cont(")\n");
}
static void print_prmd(unsigned long x)
{
printk(" PRMD: %08lx (", x);
print_plv_fragment("PPLV", (int) FIELD_GET(CSR_PRMD_PPLV, x));
print_bool_fragment("PIE", FIELD_GET(CSR_PRMD_PIE, x), false);
print_bool_fragment("PWE", FIELD_GET(CSR_PRMD_PWE, x), false);
pr_cont(")\n");
}
static void print_euen(unsigned long x)
{
printk(" EUEN: %08lx (", x);
print_bool_fragment("FPE", FIELD_GET(CSR_EUEN_FPEN, x), true);
print_bool_fragment("SXE", FIELD_GET(CSR_EUEN_LSXEN, x), false);
print_bool_fragment("ASXE", FIELD_GET(CSR_EUEN_LASXEN, x), false);
print_bool_fragment("BTE", FIELD_GET(CSR_EUEN_LBTEN, x), false);
pr_cont(")\n");
}
static void print_ecfg(unsigned long x)
{
printk(" ECFG: %08lx (", x);
print_intr_fragment("LIE", FIELD_GET(CSR_ECFG_IM, x));
pr_cont(" VS=%d)\n", (int) FIELD_GET(CSR_ECFG_VS, x));
}
static const char *humanize_exc_name(unsigned int ecode, unsigned int esubcode)
{
/*
* LoongArch users and developers are probably more familiar with
* those names found in the ISA manual, so we are going to print out
* the latter. This will require some mapping.
*/
switch (ecode) {
case EXCCODE_RSV: return "INT";
case EXCCODE_TLBL: return "PIL";
case EXCCODE_TLBS: return "PIS";
case EXCCODE_TLBI: return "PIF";
case EXCCODE_TLBM: return "PME";
case EXCCODE_TLBNR: return "PNR";
case EXCCODE_TLBNX: return "PNX";
case EXCCODE_TLBPE: return "PPI";
case EXCCODE_ADE:
switch (esubcode) {
case EXSUBCODE_ADEF: return "ADEF";
case EXSUBCODE_ADEM: return "ADEM";
}
break;
case EXCCODE_ALE: return "ALE";
case EXCCODE_BCE: return "BCE";
case EXCCODE_SYS: return "SYS";
case EXCCODE_BP: return "BRK";
case EXCCODE_INE: return "INE";
case EXCCODE_IPE: return "IPE";
case EXCCODE_FPDIS: return "FPD";
case EXCCODE_LSXDIS: return "SXD";
case EXCCODE_LASXDIS: return "ASXD";
case EXCCODE_FPE:
switch (esubcode) {
case EXCSUBCODE_FPE: return "FPE";
case EXCSUBCODE_VFPE: return "VFPE";
}
break;
case EXCCODE_WATCH:
switch (esubcode) {
case EXCSUBCODE_WPEF: return "WPEF";
case EXCSUBCODE_WPEM: return "WPEM";
}
break;
case EXCCODE_BTDIS: return "BTD";
case EXCCODE_BTE: return "BTE";
case EXCCODE_GSPR: return "GSPR";
case EXCCODE_HVC: return "HVC";
case EXCCODE_GCM:
switch (esubcode) {
case EXCSUBCODE_GCSC: return "GCSC";
case EXCSUBCODE_GCHC: return "GCHC";
}
break;
/*
* The manual did not mention the EXCCODE_SE case, but print out it
* nevertheless.
*/
case EXCCODE_SE: return "SE";
}
return "???";
}
static void print_estat(unsigned long x)
{
unsigned int ecode = FIELD_GET(CSR_ESTAT_EXC, x);
unsigned int esubcode = FIELD_GET(CSR_ESTAT_ESUBCODE, x);
printk("ESTAT: %08lx [%s] (", x, humanize_exc_name(ecode, esubcode));
print_intr_fragment("IS", FIELD_GET(CSR_ESTAT_IS, x));
pr_cont(" ECode=%d EsubCode=%d)\n", (int) ecode, (int) esubcode);
}
static void __show_regs(const struct pt_regs *regs)
{
const int field = 2 * sizeof(unsigned long);
unsigned int exccode = FIELD_GET(CSR_ESTAT_EXC, regs->csr_estat);
show_regs_print_info(KERN_DEFAULT);
/* Print saved GPRs except $zero (substituting with PC/ERA) */
#define GPR_FIELD(x) field, regs->regs[x]
printk("pc %0*lx ra %0*lx tp %0*lx sp %0*lx\n",
field, regs->csr_era, GPR_FIELD(1), GPR_FIELD(2), GPR_FIELD(3));
printk("a0 %0*lx a1 %0*lx a2 %0*lx a3 %0*lx\n",
GPR_FIELD(4), GPR_FIELD(5), GPR_FIELD(6), GPR_FIELD(7));
printk("a4 %0*lx a5 %0*lx a6 %0*lx a7 %0*lx\n",
GPR_FIELD(8), GPR_FIELD(9), GPR_FIELD(10), GPR_FIELD(11));
printk("t0 %0*lx t1 %0*lx t2 %0*lx t3 %0*lx\n",
GPR_FIELD(12), GPR_FIELD(13), GPR_FIELD(14), GPR_FIELD(15));
printk("t4 %0*lx t5 %0*lx t6 %0*lx t7 %0*lx\n",
GPR_FIELD(16), GPR_FIELD(17), GPR_FIELD(18), GPR_FIELD(19));
printk("t8 %0*lx u0 %0*lx s9 %0*lx s0 %0*lx\n",
GPR_FIELD(20), GPR_FIELD(21), GPR_FIELD(22), GPR_FIELD(23));
printk("s1 %0*lx s2 %0*lx s3 %0*lx s4 %0*lx\n",
GPR_FIELD(24), GPR_FIELD(25), GPR_FIELD(26), GPR_FIELD(27));
printk("s5 %0*lx s6 %0*lx s7 %0*lx s8 %0*lx\n",
GPR_FIELD(28), GPR_FIELD(29), GPR_FIELD(30), GPR_FIELD(31));
/* The slot for $zero is reused as the syscall restart flag */
if (regs->regs[0])
printk("syscall restart flag: %0*lx\n", GPR_FIELD(0));
if (user_mode(regs)) {
printk(" ra: %0*lx\n", GPR_FIELD(1));
printk(" ERA: %0*lx\n", field, regs->csr_era);
} else {
printk(" ra: %0*lx %pS\n", GPR_FIELD(1), (void *) regs->regs[1]);
printk(" ERA: %0*lx %pS\n", field, regs->csr_era, (void *) regs->csr_era);
}
#undef GPR_FIELD
/* Print saved important CSRs */
print_crmd(regs->csr_crmd);
print_prmd(regs->csr_prmd);
print_euen(regs->csr_euen);
print_ecfg(regs->csr_ecfg);
print_estat(regs->csr_estat);
if (exccode >= EXCCODE_TLBL && exccode <= EXCCODE_ALE)
printk(" BADV: %0*lx\n", field, regs->csr_badvaddr);
printk(" PRID: %08x (%s, %s)\n", read_cpucfg(LOONGARCH_CPUCFG0),
cpu_family_string(), cpu_full_name_string());
}
void show_regs(struct pt_regs *regs)
{
__show_regs((struct pt_regs *)regs);
dump_stack();
}
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_stacktrace(current, regs, KERN_DEFAULT, user_mode(regs));
show_code((void *)regs->csr_era, user_mode(regs));
printk("\n");
}
static DEFINE_RAW_SPINLOCK(die_lock);
void die(const char *str, struct pt_regs *regs)
{
int ret;
static int die_counter;
oops_enter();
ret = notify_die(DIE_OOPS, str, regs, 0,
current->thread.trap_nr, SIGSEGV);
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 (ret == NOTIFY_STOP)
return;
if (regs && kexec_should_crash(current))
crash_kexec(regs);
if (in_interrupt())
panic("Fatal exception in interrupt");
if (panic_on_oops)
panic("Fatal exception");
make_task_dead(SIGSEGV);
}
static inline void setup_vint_size(unsigned int size)
{
unsigned int vs;
vs = ilog2(size/4);
if (vs == 0 || vs > 7)
panic("vint_size %d Not support yet", vs);
csr_xchg32(vs<<CSR_ECFG_VS_SHIFT, CSR_ECFG_VS, LOONGARCH_CSR_ECFG);
}
/*
* Send SIGFPE according to FCSR Cause bits, which must have already
* been masked against Enable bits. This is impotant as Inexact can
* happen together with Overflow or Underflow, and `ptrace' can set
* any bits.
*/
static void force_fcsr_sig(unsigned long fcsr,
void __user *fault_addr, struct task_struct *tsk)
{
int si_code = FPE_FLTUNK;
if (fcsr & FPU_CSR_INV_X)
si_code = FPE_FLTINV;
else if (fcsr & FPU_CSR_DIV_X)
si_code = FPE_FLTDIV;
else if (fcsr & FPU_CSR_OVF_X)
si_code = FPE_FLTOVF;
else if (fcsr & FPU_CSR_UDF_X)
si_code = FPE_FLTUND;
else if (fcsr & FPU_CSR_INE_X)
si_code = FPE_FLTRES;
force_sig_fault(SIGFPE, si_code, fault_addr);
}
static int process_fpemu_return(int sig, void __user *fault_addr, unsigned long fcsr)
{
int si_code;
switch (sig) {
case 0:
return 0;
case SIGFPE:
force_fcsr_sig(fcsr, fault_addr, current);
return 1;
case SIGBUS:
force_sig_fault(SIGBUS, BUS_ADRERR, fault_addr);
return 1;
case SIGSEGV:
mmap_read_lock(current->mm);
if (vma_lookup(current->mm, (unsigned long)fault_addr))
si_code = SEGV_ACCERR;
else
si_code = SEGV_MAPERR;
mmap_read_unlock(current->mm);
force_sig_fault(SIGSEGV, si_code, fault_addr);
return 1;
default:
force_sig(sig);
return 1;
}
}
/*
* Delayed fp exceptions when doing a lazy ctx switch
*/
asmlinkage void noinstr do_fpe(struct pt_regs *regs, unsigned long fcsr)
{
int sig;
void __user *fault_addr;
irqentry_state_t state = irqentry_enter(regs);
if (notify_die(DIE_FP, "FP exception", regs, 0, current->thread.trap_nr,
SIGFPE) == NOTIFY_STOP)
goto out;
/* Clear FCSR.Cause before enabling interrupts */
write_fcsr(LOONGARCH_FCSR0, fcsr & ~mask_fcsr_x(fcsr));
local_irq_enable();
die_if_kernel("FP exception in kernel code", regs);
sig = SIGFPE;
fault_addr = (void __user *) regs->csr_era;
/* Send a signal if required. */
process_fpemu_return(sig, fault_addr, fcsr);
out:
local_irq_disable();
irqentry_exit(regs, state);
}
asmlinkage void noinstr do_ade(struct pt_regs *regs)
{
irqentry_state_t state = irqentry_enter(regs);
die_if_kernel("Kernel ade access", regs);
force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)regs->csr_badvaddr);
irqentry_exit(regs, state);
}
/* sysctl hooks */
int unaligned_enabled __read_mostly = 1; /* Enabled by default */
int no_unaligned_warning __read_mostly = 1; /* Only 1 warning by default */
asmlinkage void noinstr do_ale(struct pt_regs *regs)
{
irqentry_state_t state = irqentry_enter(regs);
#ifndef CONFIG_ARCH_STRICT_ALIGN
die_if_kernel("Kernel ale access", regs);
force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)regs->csr_badvaddr);
#else
unsigned int *pc;
perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, regs->csr_badvaddr);
/*
* Did we catch a fault trying to load an instruction?
*/
if (regs->csr_badvaddr == regs->csr_era)
goto sigbus;
if (user_mode(regs) && !test_thread_flag(TIF_FIXADE))
goto sigbus;
if (!unaligned_enabled)
goto sigbus;
if (!no_unaligned_warning)
show_registers(regs);
pc = (unsigned int *)exception_era(regs);
emulate_load_store_insn(regs, (void __user *)regs->csr_badvaddr, pc);
goto out;
sigbus:
die_if_kernel("Kernel ale access", regs);
force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)regs->csr_badvaddr);
out:
#endif
irqentry_exit(regs, state);
}
#ifdef CONFIG_GENERIC_BUG
int is_valid_bugaddr(unsigned long addr)
{
return 1;
}
#endif /* CONFIG_GENERIC_BUG */
static void bug_handler(struct pt_regs *regs)
{
switch (report_bug(regs->csr_era, regs)) {
case BUG_TRAP_TYPE_BUG:
case BUG_TRAP_TYPE_NONE:
die_if_kernel("Oops - BUG", regs);
force_sig(SIGTRAP);
break;
case BUG_TRAP_TYPE_WARN:
/* Skip the BUG instruction and continue */
regs->csr_era += LOONGARCH_INSN_SIZE;
break;
}
}
asmlinkage void noinstr do_bce(struct pt_regs *regs)
{
bool user = user_mode(regs);
unsigned long era = exception_era(regs);
u64 badv = 0, lower = 0, upper = ULONG_MAX;
union loongarch_instruction insn;
irqentry_state_t state = irqentry_enter(regs);
if (regs->csr_prmd & CSR_PRMD_PIE)
local_irq_enable();
current->thread.trap_nr = read_csr_excode();
die_if_kernel("Bounds check error in kernel code", regs);
/*
* Pull out the address that failed bounds checking, and the lower /
* upper bound, by minimally looking at the faulting instruction word
* and reading from the correct register.
*/
if (__get_inst(&insn.word, (u32 *)era, user))
goto bad_era;
switch (insn.reg3_format.opcode) {
case asrtle_op:
if (insn.reg3_format.rd != 0)
break; /* not asrtle */
badv = regs->regs[insn.reg3_format.rj];
upper = regs->regs[insn.reg3_format.rk];
break;
case asrtgt_op:
if (insn.reg3_format.rd != 0)
break; /* not asrtgt */
badv = regs->regs[insn.reg3_format.rj];
lower = regs->regs[insn.reg3_format.rk];
break;
case ldleb_op:
case ldleh_op:
case ldlew_op:
case ldled_op:
case stleb_op:
case stleh_op:
case stlew_op:
case stled_op:
case fldles_op:
case fldled_op:
case fstles_op:
case fstled_op:
badv = regs->regs[insn.reg3_format.rj];
upper = regs->regs[insn.reg3_format.rk];
break;
case ldgtb_op:
case ldgth_op:
case ldgtw_op:
case ldgtd_op:
case stgtb_op:
case stgth_op:
case stgtw_op:
case stgtd_op:
case fldgts_op:
case fldgtd_op:
case fstgts_op:
case fstgtd_op:
badv = regs->regs[insn.reg3_format.rj];
lower = regs->regs[insn.reg3_format.rk];
break;
}
force_sig_bnderr((void __user *)badv, (void __user *)lower, (void __user *)upper);
out:
if (regs->csr_prmd & CSR_PRMD_PIE)
local_irq_disable();
irqentry_exit(regs, state);
return;
bad_era:
/*
* Cannot pull out the instruction word, hence cannot provide more
* info than a regular SIGSEGV in this case.
*/
force_sig(SIGSEGV);
goto out;
}
asmlinkage void noinstr do_bp(struct pt_regs *regs)
{
bool user = user_mode(regs);
unsigned int opcode, bcode;
unsigned long era = exception_era(regs);
irqentry_state_t state = irqentry_enter(regs);
if (regs->csr_prmd & CSR_PRMD_PIE)
local_irq_enable();
if (__get_inst(&opcode, (u32 *)era, user))
goto out_sigsegv;
bcode = (opcode & 0x7fff);
/*
* notify the kprobe handlers, if instruction is likely to
* pertain to them.
*/
switch (bcode) {
case BRK_KDB:
if (kgdb_breakpoint_handler(regs))
goto out;
else
break;
case BRK_KPROBE_BP:
if (kprobe_breakpoint_handler(regs))
goto out;
else
break;
case BRK_KPROBE_SSTEPBP:
if (kprobe_singlestep_handler(regs))
goto out;
else
break;
case BRK_UPROBE_BP:
if (uprobe_breakpoint_handler(regs))
goto out;
else
break;
case BRK_UPROBE_XOLBP:
if (uprobe_singlestep_handler(regs))
goto out;
else
break;
default:
current->thread.trap_nr = read_csr_excode();
if (notify_die(DIE_TRAP, "Break", regs, bcode,
current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
goto out;
else
break;
}
switch (bcode) {
case BRK_BUG:
bug_handler(regs);
break;
case BRK_DIVZERO:
die_if_kernel("Break instruction in kernel code", regs);
force_sig_fault(SIGFPE, FPE_INTDIV, (void __user *)regs->csr_era);
break;
case BRK_OVERFLOW:
die_if_kernel("Break instruction in kernel code", regs);
force_sig_fault(SIGFPE, FPE_INTOVF, (void __user *)regs->csr_era);
break;
default:
die_if_kernel("Break instruction in kernel code", regs);
force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->csr_era);
break;
}
out:
if (regs->csr_prmd & CSR_PRMD_PIE)
local_irq_disable();
irqentry_exit(regs, state);
return;
out_sigsegv:
force_sig(SIGSEGV);
goto out;
}
asmlinkage void noinstr do_watch(struct pt_regs *regs)
{
irqentry_state_t state = irqentry_enter(regs);
#ifndef CONFIG_HAVE_HW_BREAKPOINT
pr_warn("Hardware watch point handler not implemented!\n");
#else
if (kgdb_breakpoint_handler(regs))
goto out;
if (test_tsk_thread_flag(current, TIF_SINGLESTEP)) {
int llbit = (csr_read32(LOONGARCH_CSR_LLBCTL) & 0x1);
unsigned long pc = instruction_pointer(regs);
union loongarch_instruction *ip = (union loongarch_instruction *)pc;
if (llbit) {
/*
* When the ll-sc combo is encountered, it is regarded as an single
* instruction. So don't clear llbit and reset CSR.FWPS.Skip until
* the llsc execution is completed.
*/
csr_write32(CSR_FWPC_SKIP, LOONGARCH_CSR_FWPS);
csr_write32(CSR_LLBCTL_KLO, LOONGARCH_CSR_LLBCTL);
goto out;
}
if (pc == current->thread.single_step) {
/*
* Certain insns are occasionally not skipped when CSR.FWPS.Skip is
* set, such as fld.d/fst.d. So singlestep needs to compare whether
* the csr_era is equal to the value of singlestep which last time set.
*/
if (!is_self_loop_ins(ip, regs)) {
/*
* Check if the given instruction the target pc is equal to the
* current pc, If yes, then we should not set the CSR.FWPS.SKIP
* bit to break the original instruction stream.
*/
csr_write32(CSR_FWPC_SKIP, LOONGARCH_CSR_FWPS);
goto out;
}
}
} else {
breakpoint_handler(regs);
watchpoint_handler(regs);
}
force_sig(SIGTRAP);
out:
#endif
irqentry_exit(regs, state);
}
asmlinkage void noinstr do_ri(struct pt_regs *regs)
{
int status = SIGILL;
unsigned int __maybe_unused opcode;
unsigned int __user *era = (unsigned int __user *)exception_era(regs);
irqentry_state_t state = irqentry_enter(regs);
local_irq_enable();
current->thread.trap_nr = read_csr_excode();
if (notify_die(DIE_RI, "RI Fault", regs, 0, current->thread.trap_nr,
SIGILL) == NOTIFY_STOP)
goto out;
die_if_kernel("Reserved instruction in kernel code", regs);
if (unlikely(get_user(opcode, era) < 0)) {
status = SIGSEGV;
current->thread.error_code = 1;
}
force_sig(status);
out:
local_irq_disable();
irqentry_exit(regs, state);
}
static void init_restore_fp(void)
{
if (!used_math()) {
/* First time FP context user. */
init_fpu();
} else {
/* This task has formerly used the FP context */
if (!is_fpu_owner())
own_fpu_inatomic(1);
}
BUG_ON(!is_fp_enabled());
}
static void init_restore_lsx(void)
{
enable_lsx();
if (!thread_lsx_context_live()) {
/* First time LSX context user */
init_restore_fp();
init_lsx_upper();
set_thread_flag(TIF_LSX_CTX_LIVE);
} else {
if (!is_simd_owner()) {
if (is_fpu_owner()) {
restore_lsx_upper(current);
} else {
__own_fpu();
restore_lsx(current);
}
}
}
set_thread_flag(TIF_USEDSIMD);
BUG_ON(!is_fp_enabled());
BUG_ON(!is_lsx_enabled());
}
static void init_restore_lasx(void)
{
enable_lasx();
if (!thread_lasx_context_live()) {
/* First time LASX context user */
init_restore_lsx();
init_lasx_upper();
set_thread_flag(TIF_LASX_CTX_LIVE);
} else {
if (is_fpu_owner() || is_simd_owner()) {
init_restore_lsx();
restore_lasx_upper(current);
} else {
__own_fpu();
enable_lsx();
restore_lasx(current);
}
}
set_thread_flag(TIF_USEDSIMD);
BUG_ON(!is_fp_enabled());
BUG_ON(!is_lsx_enabled());
BUG_ON(!is_lasx_enabled());
}
asmlinkage void noinstr do_fpu(struct pt_regs *regs)
{
irqentry_state_t state = irqentry_enter(regs);
local_irq_enable();
die_if_kernel("do_fpu invoked from kernel context!", regs);
BUG_ON(is_lsx_enabled());
BUG_ON(is_lasx_enabled());
preempt_disable();
init_restore_fp();
preempt_enable();
local_irq_disable();
irqentry_exit(regs, state);
}
asmlinkage void noinstr do_lsx(struct pt_regs *regs)
{
irqentry_state_t state = irqentry_enter(regs);
local_irq_enable();
if (!cpu_has_lsx) {
force_sig(SIGILL);
goto out;
}
die_if_kernel("do_lsx invoked from kernel context!", regs);
BUG_ON(is_lasx_enabled());
preempt_disable();
init_restore_lsx();
preempt_enable();
out:
local_irq_disable();
irqentry_exit(regs, state);
}
asmlinkage void noinstr do_lasx(struct pt_regs *regs)
{
irqentry_state_t state = irqentry_enter(regs);
local_irq_enable();
if (!cpu_has_lasx) {
force_sig(SIGILL);
goto out;
}
die_if_kernel("do_lasx invoked from kernel context!", regs);
preempt_disable();
init_restore_lasx();
preempt_enable();
out:
local_irq_disable();
irqentry_exit(regs, state);
}
static void init_restore_lbt(void)
{
if (!thread_lbt_context_live()) {
/* First time LBT context user */
init_lbt();
set_thread_flag(TIF_LBT_CTX_LIVE);
} else {
if (!is_lbt_owner())
own_lbt_inatomic(1);
}
BUG_ON(!is_lbt_enabled());
}
asmlinkage void noinstr do_lbt(struct pt_regs *regs)
{
irqentry_state_t state = irqentry_enter(regs);
/*
* BTD (Binary Translation Disable exception) can be triggered
* during FP save/restore if TM (Top Mode) is on, which may
* cause irq_enable during 'switch_to'. To avoid this situation
* (including the user using 'MOVGR2GCSR' to turn on TM, which
* will not trigger the BTE), we need to check PRMD first.
*/
if (regs->csr_prmd & CSR_PRMD_PIE)
local_irq_enable();
if (!cpu_has_lbt) {
force_sig(SIGILL);
goto out;
}
BUG_ON(is_lbt_enabled());
preempt_disable();
init_restore_lbt();
preempt_enable();
out:
if (regs->csr_prmd & CSR_PRMD_PIE)
local_irq_disable();
irqentry_exit(regs, state);
}
asmlinkage void noinstr do_reserved(struct pt_regs *regs)
{
irqentry_state_t state = irqentry_enter(regs);
local_irq_enable();
/*
* Game over - no way to handle this if it ever occurs. Most probably
* caused by a fatal error after another hardware/software error.
*/
pr_err("Caught reserved exception %u on pid:%d [%s] - should not happen\n",
read_csr_excode(), current->pid, current->comm);
die_if_kernel("do_reserved exception", regs);
force_sig(SIGUNUSED);
local_irq_disable();
irqentry_exit(regs, state);
}
asmlinkage void cache_parity_error(void)
{
/* For the moment, report the problem and hang. */
pr_err("Cache error exception:\n");
pr_err("csr_merrctl == %08x\n", csr_read32(LOONGARCH_CSR_MERRCTL));
pr_err("csr_merrera == %016lx\n", csr_read64(LOONGARCH_CSR_MERRERA));
panic("Can't handle the cache error!");
}
asmlinkage void noinstr handle_loongarch_irq(struct pt_regs *regs)
{
struct pt_regs *old_regs;
irq_enter_rcu();
old_regs = set_irq_regs(regs);
handle_arch_irq(regs);
set_irq_regs(old_regs);
irq_exit_rcu();
}
asmlinkage void noinstr do_vint(struct pt_regs *regs, unsigned long sp)
{
register int cpu;
register unsigned long stack;
irqentry_state_t state = irqentry_enter(regs);
cpu = smp_processor_id();
if (on_irq_stack(cpu, sp))
handle_loongarch_irq(regs);
else {
stack = per_cpu(irq_stack, cpu) + IRQ_STACK_START;
/* Save task's sp on IRQ stack for unwinding */
*(unsigned long *)stack = sp;
__asm__ __volatile__(
"move $s0, $sp \n" /* Preserve sp */
"move $sp, %[stk] \n" /* Switch stack */
"move $a0, %[regs] \n"
"bl handle_loongarch_irq \n"
"move $sp, $s0 \n" /* Restore sp */
: /* No outputs */
: [stk] "r" (stack), [regs] "r" (regs)
: "$a0", "$a1", "$a2", "$a3", "$a4", "$a5", "$a6", "$a7", "$s0",
"$t0", "$t1", "$t2", "$t3", "$t4", "$t5", "$t6", "$t7", "$t8",
"memory");
}
irqentry_exit(regs, state);
}
unsigned long eentry;
unsigned long tlbrentry;
long exception_handlers[VECSIZE * 128 / sizeof(long)] __aligned(SZ_64K);
static void configure_exception_vector(void)
{
eentry = (unsigned long)exception_handlers;
tlbrentry = (unsigned long)exception_handlers + 80*VECSIZE;
csr_write64(eentry, LOONGARCH_CSR_EENTRY);
csr_write64(eentry, LOONGARCH_CSR_MERRENTRY);
csr_write64(tlbrentry, LOONGARCH_CSR_TLBRENTRY);
}
void per_cpu_trap_init(int cpu)
{
unsigned int i;
setup_vint_size(VECSIZE);
configure_exception_vector();
if (!cpu_data[cpu].asid_cache)
cpu_data[cpu].asid_cache = asid_first_version(cpu);
mmgrab(&init_mm);
current->active_mm = &init_mm;
BUG_ON(current->mm);
enter_lazy_tlb(&init_mm, current);
/* Initialise exception handlers */
if (cpu == 0)
for (i = 0; i < 64; i++)
set_handler(i * VECSIZE, handle_reserved, VECSIZE);
tlb_init(cpu);
cpu_cache_init();
}
/* Install CPU exception handler */
void set_handler(unsigned long offset, void *addr, unsigned long size)
{
memcpy((void *)(eentry + offset), addr, size);
local_flush_icache_range(eentry + offset, eentry + offset + size);
}
static const char panic_null_cerr[] =
"Trying to set NULL cache error exception handler\n";
/*
* 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_merr_handler(unsigned long offset, void *addr, unsigned long size)
{
unsigned long uncached_eentry = TO_UNCACHE(__pa(eentry));
if (!addr)
panic(panic_null_cerr);
memcpy((void *)(uncached_eentry + offset), addr, size);
}
void __init trap_init(void)
{
long i;
/* Set interrupt vector handler */
for (i = EXCCODE_INT_START; i <= EXCCODE_INT_END; i++)
set_handler(i * VECSIZE, handle_vint, VECSIZE);
/* Set exception vector handler */
for (i = EXCCODE_ADE; i <= EXCCODE_BTDIS; i++)
set_handler(i * VECSIZE, exception_table[i], VECSIZE);
cache_error_setup();
local_flush_icache_range(eentry, eentry + 0x400);
}
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