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-rw-r--r--arch/loongarch/kernel/access-helper.h13
-rw-r--r--arch/loongarch/kernel/genex.S95
-rw-r--r--arch/loongarch/kernel/irq.c77
-rw-r--r--arch/loongarch/kernel/traps.c725
4 files changed, 910 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/access-helper.h b/arch/loongarch/kernel/access-helper.h
new file mode 100644
index 000000000000..4a35ca81bd08
--- /dev/null
+++ b/arch/loongarch/kernel/access-helper.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <linux/uaccess.h>
+
+static inline int __get_inst(u32 *i, u32 *p, bool user)
+{
+ return user ? get_user(*i, (u32 __user *)p) : get_kernel_nofault(*i, p);
+}
+
+static inline int __get_addr(unsigned long *a, unsigned long *p, bool user)
+{
+ return user ? get_user(*a, (unsigned long __user *)p) : get_kernel_nofault(*a, p);
+}
diff --git a/arch/loongarch/kernel/genex.S b/arch/loongarch/kernel/genex.S
new file mode 100644
index 000000000000..93496852b3cc
--- /dev/null
+++ b/arch/loongarch/kernel/genex.S
@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ *
+ * Derived from MIPS:
+ * Copyright (C) 1994 - 2000, 2001, 2003 Ralf Baechle
+ * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
+ * Copyright (C) 2002, 2007 Maciej W. Rozycki
+ * Copyright (C) 2001, 2012 MIPS Technologies, Inc. All rights reserved.
+ */
+#include <asm/asm.h>
+#include <asm/asmmacro.h>
+#include <asm/loongarch.h>
+#include <asm/regdef.h>
+#include <asm/fpregdef.h>
+#include <asm/stackframe.h>
+#include <asm/thread_info.h>
+
+ .align 5
+SYM_FUNC_START(__arch_cpu_idle)
+ /* start of rollback region */
+ LONG_L t0, tp, TI_FLAGS
+ nop
+ andi t0, t0, _TIF_NEED_RESCHED
+ bnez t0, 1f
+ nop
+ nop
+ nop
+ idle 0
+ /* end of rollback region */
+1: jirl zero, ra, 0
+SYM_FUNC_END(__arch_cpu_idle)
+
+SYM_FUNC_START(handle_vint)
+ BACKUP_T0T1
+ SAVE_ALL
+ la.abs t1, __arch_cpu_idle
+ LONG_L t0, sp, PT_ERA
+ /* 32 byte rollback region */
+ ori t0, t0, 0x1f
+ xori t0, t0, 0x1f
+ bne t0, t1, 1f
+ LONG_S t0, sp, PT_ERA
+1: move a0, sp
+ move a1, sp
+ la.abs t0, do_vint
+ jirl ra, t0, 0
+ RESTORE_ALL_AND_RET
+SYM_FUNC_END(handle_vint)
+
+SYM_FUNC_START(except_vec_cex)
+ b cache_parity_error
+SYM_FUNC_END(except_vec_cex)
+
+ .macro build_prep_badv
+ csrrd t0, LOONGARCH_CSR_BADV
+ PTR_S t0, sp, PT_BVADDR
+ .endm
+
+ .macro build_prep_fcsr
+ movfcsr2gr a1, fcsr0
+ .endm
+
+ .macro build_prep_none
+ .endm
+
+ .macro BUILD_HANDLER exception handler prep
+ .align 5
+ SYM_FUNC_START(handle_\exception)
+ BACKUP_T0T1
+ SAVE_ALL
+ build_prep_\prep
+ move a0, sp
+ la.abs t0, do_\handler
+ jirl ra, t0, 0
+ RESTORE_ALL_AND_RET
+ SYM_FUNC_END(handle_\exception)
+ .endm
+
+ BUILD_HANDLER ade ade badv
+ BUILD_HANDLER ale ale badv
+ BUILD_HANDLER bp bp none
+ BUILD_HANDLER fpe fpe fcsr
+ BUILD_HANDLER fpu fpu none
+ BUILD_HANDLER lsx lsx none
+ BUILD_HANDLER lasx lasx none
+ BUILD_HANDLER lbt lbt none
+ BUILD_HANDLER ri ri none
+ BUILD_HANDLER watch watch none
+ BUILD_HANDLER reserved reserved none /* others */
+
+SYM_FUNC_START(handle_sys)
+ la.abs t0, handle_syscall
+ jirl zero, t0, 0
+SYM_FUNC_END(handle_sys)
diff --git a/arch/loongarch/kernel/irq.c b/arch/loongarch/kernel/irq.c
new file mode 100644
index 000000000000..9bd07edf0bce
--- /dev/null
+++ b/arch/loongarch/kernel/irq.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#include <linux/kernel.h>
+#include <linux/acpi.h>
+#include <linux/atomic.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irqchip.h>
+#include <linux/kernel_stat.h>
+#include <linux/proc_fs.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/seq_file.h>
+#include <linux/kallsyms.h>
+#include <linux/uaccess.h>
+
+#include <asm/irq.h>
+#include <asm/loongson.h>
+#include <asm/setup.h>
+
+DEFINE_PER_CPU(unsigned long, irq_stack);
+
+struct irq_domain *cpu_domain;
+struct irq_domain *liointc_domain;
+struct irq_domain *pch_lpc_domain;
+struct irq_domain *pch_msi_domain[MAX_IO_PICS];
+struct irq_domain *pch_pic_domain[MAX_IO_PICS];
+
+/*
+ * 'what should we do if we get a hw irq event on an illegal vector'.
+ * each architecture has to answer this themselves.
+ */
+void ack_bad_irq(unsigned int irq)
+{
+ pr_warn("Unexpected IRQ # %d\n", irq);
+}
+
+atomic_t irq_err_count;
+
+asmlinkage void spurious_interrupt(void)
+{
+ atomic_inc(&irq_err_count);
+}
+
+int arch_show_interrupts(struct seq_file *p, int prec)
+{
+ seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
+ return 0;
+}
+
+void __init init_IRQ(void)
+{
+ int i;
+ unsigned int order = get_order(IRQ_STACK_SIZE);
+ struct page *page;
+
+ clear_csr_ecfg(ECFG0_IM);
+ clear_csr_estat(ESTATF_IP);
+
+ irqchip_init();
+
+ for (i = 0; i < NR_IRQS; i++)
+ irq_set_noprobe(i);
+
+ for_each_possible_cpu(i) {
+ page = alloc_pages_node(cpu_to_node(i), GFP_KERNEL, order);
+
+ per_cpu(irq_stack, i) = (unsigned long)page_address(page);
+ pr_debug("CPU%d IRQ stack at 0x%lx - 0x%lx\n", i,
+ per_cpu(irq_stack, i), per_cpu(irq_stack, i) + IRQ_STACK_SIZE);
+ }
+
+ set_csr_ecfg(ECFGF_IP0 | ECFGF_IP1 | ECFGF_IP2 | ECFGF_IPI | ECFGF_PMC);
+}
diff --git a/arch/loongarch/kernel/traps.c b/arch/loongarch/kernel/traps.c
new file mode 100644
index 000000000000..8be071b265b3
--- /dev/null
+++ b/arch/loongarch/kernel/traps.c
@@ -0,0 +1,725 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Author: Huacai Chen <chenhuacai@loongson.cn>
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#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/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/kprobes.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/fpu.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 "access-helper.h"
+
+extern asmlinkage void handle_ade(void);
+extern asmlinkage void handle_ale(void);
+extern asmlinkage void handle_sys(void);
+extern asmlinkage void handle_bp(void);
+extern asmlinkage void handle_ri(void);
+extern asmlinkage void handle_fpu(void);
+extern asmlinkage void handle_fpe(void);
+extern asmlinkage void handle_lbt(void);
+extern asmlinkage void handle_lsx(void);
+extern asmlinkage void handle_lasx(void);
+extern asmlinkage void handle_reserved(void);
+extern asmlinkage void handle_watch(void);
+extern asmlinkage void handle_vint(void);
+
+static void show_backtrace(struct task_struct *task, const struct pt_regs *regs,
+ const char *loglvl, bool user)
+{
+ unsigned long addr;
+ unsigned long *sp = (unsigned long *)(regs->regs[3] & ~3);
+
+ printk("%sCall Trace:", loglvl);
+#ifdef CONFIG_KALLSYMS
+ printk("%s\n", loglvl);
+#endif
+ while (!kstack_end(sp)) {
+ if (__get_addr(&addr, sp++, user)) {
+ printk("%s (Bad stack address)", loglvl);
+ break;
+ }
+ if (__kernel_text_address(addr))
+ 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 __show_regs(const struct pt_regs *regs)
+{
+ const int field = 2 * sizeof(unsigned long);
+ unsigned int excsubcode;
+ unsigned int exccode;
+ int i;
+
+ show_regs_print_info(KERN_DEFAULT);
+
+ /*
+ * Saved main processor registers
+ */
+ for (i = 0; i < 32; ) {
+ if ((i % 4) == 0)
+ printk("$%2d :", i);
+ pr_cont(" %0*lx", field, regs->regs[i]);
+
+ i++;
+ if ((i % 4) == 0)
+ pr_cont("\n");
+ }
+
+ /*
+ * Saved csr registers
+ */
+ printk("era : %0*lx %pS\n", field, regs->csr_era,
+ (void *) regs->csr_era);
+ printk("ra : %0*lx %pS\n", field, regs->regs[1],
+ (void *) regs->regs[1]);
+
+ printk("CSR crmd: %08lx ", regs->csr_crmd);
+ printk("CSR prmd: %08lx ", regs->csr_prmd);
+ printk("CSR euen: %08lx ", regs->csr_euen);
+ printk("CSR ecfg: %08lx ", regs->csr_ecfg);
+ printk("CSR estat: %08lx ", regs->csr_estat);
+
+ pr_cont("\n");
+
+ exccode = ((regs->csr_estat) & CSR_ESTAT_EXC) >> CSR_ESTAT_EXC_SHIFT;
+ excsubcode = ((regs->csr_estat) & CSR_ESTAT_ESUBCODE) >> CSR_ESTAT_ESUBCODE_SHIFT;
+ printk("ExcCode : %x (SubCode %x)\n", exccode, excsubcode);
+
+ if (exccode >= EXCCODE_TLBL && exccode <= EXCCODE_ALE)
+ printk("BadVA : %0*lx\n", field, regs->csr_badvaddr);
+
+ printk("PrId : %08x (%s)\n", read_cpucfg(LOONGARCH_CPUCFG0),
+ cpu_family_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 __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, current->thread.trap_nr,
+ 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)
+ panic("Fatal exception");
+
+ make_task_dead(sig);
+}
+
+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.
+ */
+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);
+}
+
+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);
+}
+
+asmlinkage void noinstr do_ale(struct pt_regs *regs)
+{
+ irqentry_state_t state = irqentry_enter(regs);
+
+ die_if_kernel("Kernel ale access", regs);
+ force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)regs->csr_badvaddr);
+
+ irqentry_exit(regs, state);
+}
+
+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);
+
+ local_irq_enable();
+ current->thread.trap_nr = read_csr_excode();
+ 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_KPROBE_BP:
+ if (notify_die(DIE_BREAK, "Kprobe", regs, bcode,
+ current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
+ goto out;
+ else
+ break;
+ case BRK_KPROBE_SSTEPBP:
+ if (notify_die(DIE_SSTEPBP, "Kprobe_SingleStep", regs, bcode,
+ current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
+ goto out;
+ else
+ break;
+ case BRK_UPROBE_BP:
+ if (notify_die(DIE_UPROBE, "Uprobe", regs, bcode,
+ current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
+ goto out;
+ else
+ break;
+ case BRK_UPROBE_XOLBP:
+ if (notify_die(DIE_UPROBE_XOL, "Uprobe_XOL", regs, bcode,
+ current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
+ goto out;
+ else
+ break;
+ default:
+ if (notify_die(DIE_TRAP, "Break", regs, bcode,
+ current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
+ goto out;
+ else
+ break;
+ }
+
+ switch (bcode) {
+ case BRK_BUG:
+ die_if_kernel("Kernel bug detected", regs);
+ force_sig(SIGTRAP);
+ 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:
+ local_irq_disable();
+ irqentry_exit(regs, state);
+ return;
+
+out_sigsegv:
+ force_sig(SIGSEGV);
+ goto out;
+}
+
+asmlinkage void noinstr do_watch(struct pt_regs *regs)
+{
+ pr_warn("Hardware watch point handler not implemented!\n");
+}
+
+asmlinkage void noinstr do_ri(struct pt_regs *regs)
+{
+ int status = -1;
+ unsigned int opcode = 0;
+ unsigned int __user *era = (unsigned int __user *)exception_era(regs);
+ unsigned long old_era = regs->csr_era;
+ unsigned long old_ra = regs->regs[1];
+ 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(compute_return_era(regs) < 0))
+ goto out;
+
+ if (unlikely(get_user(opcode, era) < 0)) {
+ status = SIGSEGV;
+ current->thread.error_code = 1;
+ }
+
+ if (status < 0)
+ status = SIGILL;
+
+ if (unlikely(status > 0)) {
+ regs->csr_era = old_era; /* Undo skip-over. */
+ regs->regs[1] = old_ra;
+ 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());
+}
+
+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);
+
+ 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();
+ force_sig(SIGILL);
+ 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();
+ force_sig(SIGILL);
+ local_irq_disable();
+
+ irqentry_exit(regs, state);
+}
+
+asmlinkage void noinstr do_lbt(struct pt_regs *regs)
+{
+ irqentry_state_t state = irqentry_enter(regs);
+
+ local_irq_enable();
+ force_sig(SIGILL);
+ 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 == %016llx\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);
+}
+
+extern void tlb_init(void);
+extern void cache_error_setup(void);
+
+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_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_handler(EXCCODE_ADE * VECSIZE, handle_ade, VECSIZE);
+ set_handler(EXCCODE_ALE * VECSIZE, handle_ale, VECSIZE);
+ set_handler(EXCCODE_SYS * VECSIZE, handle_sys, VECSIZE);
+ set_handler(EXCCODE_BP * VECSIZE, handle_bp, VECSIZE);
+ set_handler(EXCCODE_INE * VECSIZE, handle_ri, VECSIZE);
+ set_handler(EXCCODE_IPE * VECSIZE, handle_ri, VECSIZE);
+ set_handler(EXCCODE_FPDIS * VECSIZE, handle_fpu, VECSIZE);
+ set_handler(EXCCODE_LSXDIS * VECSIZE, handle_lsx, VECSIZE);
+ set_handler(EXCCODE_LASXDIS * VECSIZE, handle_lasx, VECSIZE);
+ set_handler(EXCCODE_FPE * VECSIZE, handle_fpe, VECSIZE);
+ set_handler(EXCCODE_BTDIS * VECSIZE, handle_lbt, VECSIZE);
+ set_handler(EXCCODE_WATCH * VECSIZE, handle_watch, VECSIZE);
+
+ cache_error_setup();
+
+ local_flush_icache_range(eentry, eentry + 0x400);
+}