diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h
index 0b1bc7ed913b..78cf7e300f12 100644
--- a/arch/mips/include/asm/cpu-features.h
+++ b/arch/mips/include/asm/cpu-features.h
@@ -572,6 +572,10 @@
 # define cpu_has_ftlbparex	__opt(MIPS_CPU_FTLBPAREX)
 #endif
 
+#ifndef cpu_has_gsexcex
+# define cpu_has_gsexcex	__opt(MIPS_CPU_GSEXCEX)
+#endif
+
 #ifdef CONFIG_SMP
 /*
  * Some systems share FTLB RAMs between threads within a core (siblings in
diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h
index 9d08bd33b11f..388a82f28a87 100644
--- a/arch/mips/include/asm/cpu.h
+++ b/arch/mips/include/asm/cpu.h
@@ -428,6 +428,7 @@ enum cpu_type_enum {
 #define MIPS_CPU_MM_FULL	BIT_ULL(59)	/* CPU supports write-through full merge */
 #define MIPS_CPU_MAC_2008_ONLY	BIT_ULL(60)	/* CPU Only support MAC2008 Fused multiply-add instruction */
 #define MIPS_CPU_FTLBPAREX	BIT_ULL(61)	/* CPU has FTLB parity exception */
+#define MIPS_CPU_GSEXCEX	BIT_ULL(62)	/* CPU has GSExc exception */
 
 /*
  * CPU ASE encodings
diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h
index 5ba268266d16..4ddc12e4444a 100644
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -474,6 +474,9 @@
 /* Implementation specific trap codes used by MIPS cores */
 #define MIPS_EXCCODE_TLBPAR	16	/* TLB parity error exception */
 
+/* Implementation specific trap codes used by Loongson cores */
+#define LOONGSON_EXCCODE_GSEXC	16	/* Loongson-specific exception */
+
 /*
  * Bits in the coprocessor 0 config register.
  */
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index 519d101fd009..e2955f1f6316 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -2043,6 +2043,9 @@ static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu)
 {
 	decode_configs(c);
 
+	/* All Loongson processors covered here define ExcCode 16 as GSExc. */
+	c->options |= MIPS_CPU_GSEXCEX;
+
 	switch (c->processor_id & PRID_IMP_MASK) {
 	case PRID_IMP_LOONGSON_64R: /* Loongson-64 Reduced */
 		switch (c->processor_id & PRID_REV_MASK) {
diff --git a/arch/mips/kernel/genex.S b/arch/mips/kernel/genex.S
index a1b966f3578e..bcce32a3de10 100644
--- a/arch/mips/kernel/genex.S
+++ b/arch/mips/kernel/genex.S
@@ -498,6 +498,19 @@ NESTED(nmi_handler, PT_SIZE, sp)
 	KMODE
 	.endm
 
+	.macro __build_clear_gsexc
+	.set	push
+	/*
+	 * We need to specify a selector to access the CP0.Diag1 (GSCause)
+	 * register. All GSExc-equipped processors have MIPS32.
+	 */
+	.set	mips32
+	mfc0	a1, CP0_DIAGNOSTIC1
+	.set	pop
+	TRACE_IRQS_ON
+	STI
+	.endm
+
 	.macro	__BUILD_silent exception
 	.endm
 
@@ -556,6 +569,7 @@ NESTED(nmi_handler, PT_SIZE, sp)
 	BUILD_HANDLER fpe fpe fpe silent		/* #15 */
 #endif
 	BUILD_HANDLER ftlb ftlb none silent		/* #16 */
+	BUILD_HANDLER gsexc gsexc gsexc silent		/* #16 */
 	BUILD_HANDLER msa msa sti silent		/* #21 */
 	BUILD_HANDLER mdmx mdmx sti silent		/* #22 */
 #ifdef	CONFIG_HARDWARE_WATCHPOINTS
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 9c37a6997259..b95ef98fc847 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -90,6 +90,7 @@ 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_gsexc(void);
 extern asmlinkage void handle_msa(void);
 extern asmlinkage void handle_mdmx(void);
 extern asmlinkage void handle_watch(void);
@@ -1900,6 +1901,37 @@ asmlinkage void do_ftlb(void)
 	cache_parity_error();
 }
 
+asmlinkage void do_gsexc(struct pt_regs *regs, u32 diag1)
+{
+	u32 exccode = (diag1 & LOONGSON_DIAG1_EXCCODE) >>
+			LOONGSON_DIAG1_EXCCODE_SHIFT;
+	enum ctx_state prev_state;
+
+	prev_state = exception_enter();
+
+	switch (exccode) {
+	case 0x08:
+		/* Undocumented exception, will trigger on certain
+		 * also-undocumented instructions accessible from userspace.
+		 * Processor state is not otherwise corrupted, but currently
+		 * we don't know how to proceed. Maybe there is some
+		 * undocumented control flag to enable the instructions?
+		 */
+		force_sig(SIGILL);
+		break;
+
+	default:
+		/* None of the other exceptions, documented or not, have
+		 * further details given; none are encountered in the wild
+		 * either. Panic in case some of them turn out to be fatal.
+		 */
+		show_regs(regs);
+		panic("Unhandled Loongson exception - GSCause = %08x", diag1);
+	}
+
+	exception_exit(prev_state);
+}
+
 /*
  * SDBBP EJTAG debug exception handler.
  * We skip the instruction and return to the next instruction.
@@ -2457,6 +2489,9 @@ void __init trap_init(void)
 	if (cpu_has_ftlbparex)
 		set_except_vector(MIPS_EXCCODE_TLBPAR, handle_ftlb);
 
+	if (cpu_has_gsexcex)
+		set_except_vector(LOONGSON_EXCCODE_GSEXC, handle_gsexc);
+
 	if (cpu_has_rixiex) {
 		set_except_vector(EXCCODE_TLBRI, tlb_do_page_fault_0);
 		set_except_vector(EXCCODE_TLBXI, tlb_do_page_fault_0);