Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index 0677142..41bb91f 100644
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -391,6 +391,7 @@
 static void build_restore_work_registers(u32 **p)
 {
 	if (scratch_reg >= 0) {
+		uasm_i_ehb(p);
 		UASM_i_MFC0(p, 1, c0_kscratch(), scratch_reg);
 		return;
 	}
@@ -544,7 +545,6 @@
 		tlbw(p);
 		break;
 
-	case CPU_R4300:
 	case CPU_5KC:
 	case CPU_TX49XX:
 	case CPU_PR4450:
@@ -576,6 +576,7 @@
 	case CPU_R5500:
 		if (m4kc_tlbp_war())
 			uasm_i_nop(p);
+		/* fall through */
 	case CPU_ALCHEMY:
 		tlbw(p);
 		break;
@@ -602,13 +603,12 @@
 
 	case CPU_VR4131:
 	case CPU_VR4133:
-	case CPU_R5432:
 		uasm_i_nop(p);
 		uasm_i_nop(p);
 		tlbw(p);
 		break;
 
-	case CPU_JZRISC:
+	case CPU_XBURST:
 		tlbw(p);
 		uasm_i_nop(p);
 		break;
@@ -629,7 +629,7 @@
 		return;
 	}
 
-	if (cpu_has_rixi && _PAGE_NO_EXEC) {
+	if (cpu_has_rixi && !!_PAGE_NO_EXEC) {
 		if (fill_includes_sw_bits) {
 			UASM_i_ROTR(p, reg, reg, ilog2(_PAGE_GLOBAL));
 		} else {
@@ -653,6 +653,13 @@
 				   int restore_scratch)
 {
 	if (restore_scratch) {
+		/*
+		 * Ensure the MFC0 below observes the value written to the
+		 * KScratch register by the prior MTC0.
+		 */
+		if (scratch_reg >= 0)
+			uasm_i_ehb(p);
+
 		/* Reset default page size */
 		if (PM_DEFAULT_MASK >> 16) {
 			uasm_i_lui(p, tmp, PM_DEFAULT_MASK >> 16);
@@ -919,6 +926,10 @@
 	}
 	if (mode != not_refill && check_for_high_segbits) {
 		uasm_l_large_segbits_fault(l, *p);
+
+		if (mode == refill_scratch && scratch_reg >= 0)
+			uasm_i_ehb(p);
+
 		/*
 		 * We get here if we are an xsseg address, or if we are
 		 * an xuseg address above (PGDIR_SHIFT+PGDIR_BITS) boundary.
@@ -931,6 +942,8 @@
 		 * to mimic that here by taking a load/istream page
 		 * fault.
 		 */
+		if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS))
+			uasm_i_sync(p, 0);
 		UASM_i_LA(p, ptr, (unsigned long)tlb_do_page_fault_0);
 		uasm_i_jr(p, ptr);
 
@@ -1255,6 +1268,7 @@
 	UASM_i_MTC0(p, odd, C0_ENTRYLO1); /* load it */
 
 	if (c0_scratch_reg >= 0) {
+		uasm_i_ehb(p);
 		UASM_i_MFC0(p, scratch, c0_kscratch(), c0_scratch_reg);
 		build_tlb_write_entry(p, l, r, tlb_random);
 		uasm_l_leave(l, *p);
@@ -1600,15 +1614,17 @@
 		uasm_i_dinsm(&p, a0, 0, 29, 64 - 29);
 		uasm_l_tlbl_goaround1(&l, p);
 		UASM_i_SLL(&p, a0, a0, 11);
-		uasm_i_jr(&p, 31);
 		UASM_i_MTC0(&p, a0, C0_CONTEXT);
+		uasm_i_jr(&p, 31);
+		uasm_i_ehb(&p);
 	} else {
 		/* PGD in c0_KScratch */
-		uasm_i_jr(&p, 31);
 		if (cpu_has_ldpte)
 			UASM_i_MTC0(&p, a0, C0_PWBASE);
 		else
 			UASM_i_MTC0(&p, a0, c0_kscratch(), pgd_reg);
+		uasm_i_jr(&p, 31);
+		uasm_i_ehb(&p);
 	}
 #else
 #ifdef CONFIG_SMP
@@ -1622,13 +1638,16 @@
 	UASM_i_LA_mostly(&p, a2, pgdc);
 	UASM_i_SW(&p, a0, uasm_rel_lo(pgdc), a2);
 #endif /* SMP */
-	uasm_i_jr(&p, 31);
 
 	/* if pgd_reg is allocated, save PGD also to scratch register */
-	if (pgd_reg != -1)
+	if (pgd_reg != -1) {
 		UASM_i_MTC0(&p, a0, c0_kscratch(), pgd_reg);
-	else
+		uasm_i_jr(&p, 31);
+		uasm_i_ehb(&p);
+	} else {
+		uasm_i_jr(&p, 31);
 		uasm_i_nop(&p);
+	}
 #endif
 	if (p >= (u32 *)tlbmiss_handler_setup_pgd_end)
 		panic("tlbmiss_handler_setup_pgd space exceeded");
@@ -1645,6 +1664,8 @@
 iPTE_LW(u32 **p, unsigned int pte, unsigned int ptr)
 {
 #ifdef CONFIG_SMP
+	if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS))
+		uasm_i_sync(p, 0);
 # ifdef CONFIG_PHYS_ADDR_T_64BIT
 	if (cpu_has_64bits)
 		uasm_i_lld(p, pte, 0, ptr);
@@ -2258,6 +2279,8 @@
 #endif
 
 	uasm_l_nopage_tlbl(&l, p);
+	if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS))
+		uasm_i_sync(&p, 0);
 	build_restore_work_registers(&p);
 #ifdef CONFIG_CPU_MICROMIPS
 	if ((unsigned long)tlb_do_page_fault_0 & 1) {
@@ -2312,6 +2335,8 @@
 #endif
 
 	uasm_l_nopage_tlbs(&l, p);
+	if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS))
+		uasm_i_sync(&p, 0);
 	build_restore_work_registers(&p);
 #ifdef CONFIG_CPU_MICROMIPS
 	if ((unsigned long)tlb_do_page_fault_1 & 1) {
@@ -2367,6 +2392,8 @@
 #endif
 
 	uasm_l_nopage_tlbm(&l, p);
+	if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS))
+		uasm_i_sync(&p, 0);
 	build_restore_work_registers(&p);
 #ifdef CONFIG_CPU_MICROMIPS
 	if ((unsigned long)tlb_do_page_fault_1 & 1) {
@@ -2587,21 +2614,11 @@
 	check_for_high_segbits = current_cpu_data.vmbits > (PGDIR_SHIFT + PGD_ORDER + PAGE_SHIFT - 3);
 #endif
 
-	switch (current_cpu_type()) {
-	case CPU_R2000:
-	case CPU_R3000:
-	case CPU_R3000A:
-	case CPU_R3081E:
-	case CPU_TX3912:
-	case CPU_TX3922:
-	case CPU_TX3927:
+	if (cpu_has_3kex) {
 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
-		if (cpu_has_local_ebase)
-			build_r3000_tlb_refill_handler();
 		if (!run_once) {
-			if (!cpu_has_local_ebase)
-				build_r3000_tlb_refill_handler();
 			build_setup_pgd();
+			build_r3000_tlb_refill_handler();
 			build_r3000_tlb_load_handler();
 			build_r3000_tlb_store_handler();
 			build_r3000_tlb_modify_handler();
@@ -2611,34 +2628,27 @@
 #else
 		panic("No R3000 TLB refill handler");
 #endif
-		break;
-
-	case CPU_R8000:
-		panic("No R8000 TLB refill handler yet");
-		break;
-
-	default:
-		if (cpu_has_ldpte)
-			setup_pw();
-
-		if (!run_once) {
-			scratch_reg = allocate_kscratch();
-			build_setup_pgd();
-			build_r4000_tlb_load_handler();
-			build_r4000_tlb_store_handler();
-			build_r4000_tlb_modify_handler();
-			if (cpu_has_ldpte)
-				build_loongson3_tlb_refill_handler();
-			else if (!cpu_has_local_ebase)
-				build_r4000_tlb_refill_handler();
-			flush_tlb_handlers();
-			run_once++;
-		}
-		if (cpu_has_local_ebase)
-			build_r4000_tlb_refill_handler();
-		if (cpu_has_xpa)
-			config_xpa_params();
-		if (cpu_has_htw)
-			config_htw_params();
+		return;
 	}
+
+	if (cpu_has_ldpte)
+		setup_pw();
+
+	if (!run_once) {
+		scratch_reg = allocate_kscratch();
+		build_setup_pgd();
+		build_r4000_tlb_load_handler();
+		build_r4000_tlb_store_handler();
+		build_r4000_tlb_modify_handler();
+		if (cpu_has_ldpte)
+			build_loongson3_tlb_refill_handler();
+		else
+			build_r4000_tlb_refill_handler();
+		flush_tlb_handlers();
+		run_once++;
+	}
+	if (cpu_has_xpa)
+		config_xpa_params();
+	if (cpu_has_htw)
+		config_htw_params();
 }