diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h
index 404390b..3f11e52 100644
--- a/arch/mips/include/asm/cpu-features.h
+++ b/arch/mips/include/asm/cpu-features.h
@@ -484,7 +484,6 @@
 # endif
 # ifndef cpu_vmbits
 # define cpu_vmbits cpu_data[0].vmbits
-# define __NEED_VMBITS_PROBE
 # endif
 #endif
 
diff --git a/arch/mips/include/asm/cpu-info.h b/arch/mips/include/asm/cpu-info.h
index fd60837..211b578 100644
--- a/arch/mips/include/asm/cpu-info.h
+++ b/arch/mips/include/asm/cpu-info.h
@@ -80,9 +80,7 @@ struct cpuinfo_mips {
 	int			srsets; /* Shadow register sets */
 	int			package;/* physical package number */
 	unsigned int		globalnumber;
-#ifdef CONFIG_64BIT
 	int			vmbits; /* Virtual memory size in bits */
-#endif
 	void			*data;	/* Additional data */
 	unsigned int		watch_reg_count;   /* Number that exist */
 	unsigned int		watch_reg_use_cnt; /* Usable by ptrace */
diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h
index f799c0d..12a095d 100644
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -1871,6 +1871,8 @@ do {									\
 
 #define read_c0_entryhi()	__read_ulong_c0_register($10, 0)
 #define write_c0_entryhi(val)	__write_ulong_c0_register($10, 0, val)
+#define read_c0_entryhi_64()	__read_64bit_c0_register($10, 0)
+#define write_c0_entryhi_64(val) __write_64bit_c0_register($10, 0, val)
 
 #define read_c0_guestctl1()	__read_32bit_c0_register($10, 4)
 #define write_c0_guestctl1(val)	__write_32bit_c0_register($10, 4, val)
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index 1e49e05..489612e 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -210,11 +210,14 @@ static inline void set_elf_base_platform(const char *plat)
 
 static inline void cpu_probe_vmbits(struct cpuinfo_mips *c)
 {
-#ifdef __NEED_VMBITS_PROBE
-	write_c0_entryhi(0x3fffffffffffe000ULL);
-	back_to_back_c0_hazard();
-	c->vmbits = fls64(read_c0_entryhi() & 0x3fffffffffffe000ULL);
-#endif
+	int vmbits = 31;
+
+	if (cpu_has_64bits) {
+		write_c0_entryhi_64(0x3fffffffffffe000ULL);
+		back_to_back_c0_hazard();
+		vmbits = fls64(read_c0_entryhi_64() & 0x3fffffffffffe000ULL);
+	}
+	c->vmbits = vmbits;
 }
 
 static void set_isa(struct cpuinfo_mips *c, unsigned int isa)
diff --git a/arch/mips/kernel/cpu-r3k-probe.c b/arch/mips/kernel/cpu-r3k-probe.c
index 0c826f7..edcf04d 100644
--- a/arch/mips/kernel/cpu-r3k-probe.c
+++ b/arch/mips/kernel/cpu-r3k-probe.c
@@ -137,6 +137,8 @@ void cpu_probe(void)
 	else
 		cpu_set_nofpu_opts(c);
 
+	c->vmbits = 31;
+
 	reserve_exception_space(0, 0x400);
 }
 
diff --git a/arch/mips/lib/multi3.c b/arch/mips/lib/multi3.c
index 4c2483f..92b3778 100644
--- a/arch/mips/lib/multi3.c
+++ b/arch/mips/lib/multi3.c
@@ -4,12 +4,12 @@
 #include "libgcc.h"
 
 /*
- * GCC 7 & older can suboptimally generate __multi3 calls for mips64r6, so for
+ * GCC 9 & older can suboptimally generate __multi3 calls for mips64r6, so for
  * that specific case only we implement that intrinsic here.
  *
  * See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82981
  */
-#if defined(CONFIG_64BIT) && defined(CONFIG_CPU_MIPSR6) && (__GNUC__ < 8)
+#if defined(CONFIG_64BIT) && defined(CONFIG_CPU_MIPSR6) && (__GNUC__ < 10)
 
 /* multiply 64-bit values, low 64-bits returned */
 static inline long long notrace dmulu(long long a, long long b)
@@ -51,4 +51,4 @@ ti_type notrace __multi3(ti_type a, ti_type b)
 }
 EXPORT_SYMBOL(__multi3);
 
-#endif /* 64BIT && CPU_MIPSR6 && GCC7 */
+#endif /* 64BIT && CPU_MIPSR6 && GCC9 */
diff --git a/arch/mips/loongson64/env.c b/arch/mips/loongson64/env.c
index 11ddf02..7abcca7 100644
--- a/arch/mips/loongson64/env.c
+++ b/arch/mips/loongson64/env.c
@@ -17,7 +17,9 @@
 #include <linux/dma-map-ops.h>
 #include <linux/export.h>
 #include <linux/libfdt.h>
+#include <linux/minmax.h>
 #include <linux/pci_ids.h>
+#include <linux/serial_core.h>
 #include <linux/string_choices.h>
 #include <asm/bootinfo.h>
 #include <loongson.h>
@@ -106,9 +108,23 @@ static void __init lefi_fixup_fdt(struct system_loongson *system)
 
 	is_loongson64g = (read_c0_prid() & PRID_IMP_MASK) == PRID_IMP_LOONGSON_64G;
 
-	for (i = 0; i < system->nr_uarts; i++) {
+	for (i = 0; i < min(system->nr_uarts, MAX_UARTS); i++) {
 		uartdev = &system->uarts[i];
 
+		/*
+		 * Some firmware does not set nr_uarts properly and passes empty
+		 * items. Ignore them silently.
+		 */
+		if (uartdev->uart_base == 0)
+			continue;
+
+		/* Our DT only works with UPIO_MEM. */
+		if (uartdev->iotype != UPIO_MEM) {
+			pr_warn("Ignore UART 0x%llx with iotype %u passed by firmware\n",
+				uartdev->uart_base, uartdev->iotype);
+			continue;
+		}
+
 		ret = lefi_fixup_fdt_serial(fdt_buf, uartdev->uart_base,
 					    uartdev->uartclk);
 		/*
diff --git a/arch/mips/mm/cache.c b/arch/mips/mm/cache.c
index e3b4224..ad9b043 100644
--- a/arch/mips/mm/cache.c
+++ b/arch/mips/mm/cache.c
@@ -207,7 +207,8 @@ void cpu_cache_init(void)
 {
 	if (IS_ENABLED(CONFIG_CPU_R3000) && cpu_has_3k_cache)
 		r3k_cache_init();
-	if (IS_ENABLED(CONFIG_CPU_R4K_CACHE_TLB) && cpu_has_4k_cache)
+	if ((IS_ENABLED(CONFIG_CPU_R4K_CACHE_TLB) ||
+	     IS_ENABLED(CONFIG_CPU_SB1)) && cpu_has_4k_cache)
 		r4k_cache_init();
 
 	if (IS_ENABLED(CONFIG_CPU_CAVIUM_OCTEON) && cpu_has_octeon_cache)
diff --git a/arch/mips/mm/tlb-r4k.c b/arch/mips/mm/tlb-r4k.c
index 44a6625..24fe85f 100644
--- a/arch/mips/mm/tlb-r4k.c
+++ b/arch/mips/mm/tlb-r4k.c
@@ -13,6 +13,7 @@
 #include <linux/sched.h>
 #include <linux/smp.h>
 #include <linux/memblock.h>
+#include <linux/minmax.h>
 #include <linux/mm.h>
 #include <linux/hugetlb.h>
 #include <linux/export.h>
@@ -24,6 +25,7 @@
 #include <asm/hazards.h>
 #include <asm/mmu_context.h>
 #include <asm/tlb.h>
+#include <asm/tlbdebug.h>
 #include <asm/tlbex.h>
 #include <asm/tlbmisc.h>
 #include <asm/setup.h>
@@ -511,87 +513,259 @@ static int __init set_ntlb(char *str)
 __setup("ntlb=", set_ntlb);
 
 
-/* Comparison function for EntryHi VPN fields.  */
-static int r4k_vpn_cmp(const void *a, const void *b)
+/* The start bit position of VPN2 and Mask in EntryHi/PageMask registers.  */
+#define VPN2_SHIFT 13
+
+/* Read full EntryHi even with CONFIG_32BIT.  */
+static inline unsigned long long read_c0_entryhi_native(void)
+{
+	return cpu_has_64bits ? read_c0_entryhi_64() : read_c0_entryhi();
+}
+
+/* Write full EntryHi even with CONFIG_32BIT.  */
+static inline void write_c0_entryhi_native(unsigned long long v)
 {
-	long v = *(unsigned long *)a - *(unsigned long *)b;
-	int s = sizeof(long) > sizeof(int) ? sizeof(long) * 8 - 1: 0;
-	return s ? (v != 0) | v >> s : v;
+	if (cpu_has_64bits)
+		write_c0_entryhi_64(v);
+	else
+		write_c0_entryhi(v);
 }
 
+/* TLB entry state for uniquification.  */
+struct tlbent {
+	unsigned long long wired:1;
+	unsigned long long global:1;
+	unsigned long long asid:10;
+	unsigned long long vpn:51;
+	unsigned long long pagesz:5;
+	unsigned long long index:14;
+};
+
 /*
- * Initialise all TLB entries with unique values that do not clash with
- * what we have been handed over and what we'll be using ourselves.
+ * Comparison function for TLB entry sorting.  Place wired entries first,
+ * then global entries, then order by the increasing VPN/ASID and the
+ * decreasing page size.  This lets us avoid clashes with wired entries
+ * easily and get entries for larger pages out of the way first.
+ *
+ * We could group bits so as to reduce the number of comparisons, but this
+ * is seldom executed and not performance-critical, so prefer legibility.
  */
-static void __ref r4k_tlb_uniquify(void)
+static int r4k_entry_cmp(const void *a, const void *b)
 {
-	int tlbsize = current_cpu_data.tlbsize;
-	bool use_slab = slab_is_available();
-	int start = num_wired_entries();
-	phys_addr_t tlb_vpn_size;
-	unsigned long *tlb_vpns;
-	unsigned long vpn_mask;
-	int cnt, ent, idx, i;
-
-	vpn_mask = GENMASK(cpu_vmbits - 1, 13);
-	vpn_mask |= IS_ENABLED(CONFIG_64BIT) ? 3ULL << 62 : 1 << 31;
+	struct tlbent ea = *(struct tlbent *)a, eb = *(struct tlbent *)b;
+
+	if (ea.wired > eb.wired)
+		return -1;
+	else if (ea.wired < eb.wired)
+		return 1;
+	else if (ea.global > eb.global)
+		return -1;
+	else if (ea.global < eb.global)
+		return 1;
+	else if (ea.vpn < eb.vpn)
+		return -1;
+	else if (ea.vpn > eb.vpn)
+		return 1;
+	else if (ea.asid < eb.asid)
+		return -1;
+	else if (ea.asid > eb.asid)
+		return 1;
+	else if (ea.pagesz > eb.pagesz)
+		return -1;
+	else if (ea.pagesz < eb.pagesz)
+		return 1;
+	else
+		return 0;
+}
 
-	tlb_vpn_size = tlbsize * sizeof(*tlb_vpns);
-	tlb_vpns = (use_slab ?
-		    kmalloc(tlb_vpn_size, GFP_KERNEL) :
-		    memblock_alloc_raw(tlb_vpn_size, sizeof(*tlb_vpns)));
-	if (WARN_ON(!tlb_vpns))
-		return; /* Pray local_flush_tlb_all() is good enough. */
+/*
+ * Fetch all the TLB entries.  Mask individual VPN values retrieved with
+ * the corresponding page mask and ignoring any 1KiB extension as we'll
+ * be using 4KiB pages for uniquification.
+ */
+static void __ref r4k_tlb_uniquify_read(struct tlbent *tlb_vpns, int tlbsize)
+{
+	int start = num_wired_entries();
+	unsigned long long vpn_mask;
+	bool global;
+	int i;
 
-	htw_stop();
+	vpn_mask = GENMASK(current_cpu_data.vmbits - 1, VPN2_SHIFT);
+	vpn_mask |= cpu_has_64bits ? 3ULL << 62 : 1 << 31;
 
-	for (i = start, cnt = 0; i < tlbsize; i++, cnt++) {
-		unsigned long vpn;
+	for (i = 0; i < tlbsize; i++) {
+		unsigned long long entryhi, vpn, mask, asid;
+		unsigned int pagesz;
 
 		write_c0_index(i);
 		mtc0_tlbr_hazard();
 		tlb_read();
 		tlb_read_hazard();
-		vpn = read_c0_entryhi();
-		vpn &= vpn_mask & PAGE_MASK;
-		tlb_vpns[cnt] = vpn;
 
-		/* Prevent any large pages from overlapping regular ones.  */
-		write_c0_pagemask(read_c0_pagemask() & PM_DEFAULT_MASK);
-		mtc0_tlbw_hazard();
-		tlb_write_indexed();
-		tlbw_use_hazard();
+		global = !!(read_c0_entrylo0() & ENTRYLO_G);
+		entryhi = read_c0_entryhi_native();
+		mask = read_c0_pagemask();
+
+		asid = entryhi & cpu_asid_mask(&current_cpu_data);
+		vpn = (entryhi & vpn_mask & ~mask) >> VPN2_SHIFT;
+		pagesz = ilog2((mask >> VPN2_SHIFT) + 1);
+
+		tlb_vpns[i].global = global;
+		tlb_vpns[i].asid = global ? 0 : asid;
+		tlb_vpns[i].vpn = vpn;
+		tlb_vpns[i].pagesz = pagesz;
+		tlb_vpns[i].wired = i < start;
+		tlb_vpns[i].index = i;
 	}
+}
+
+/*
+ * Write unique values to all but the wired TLB entries each, using
+ * the 4KiB page size.  This size might not be supported with R6, but
+ * EHINV is mandatory for R6, so we won't ever be called in that case.
+ *
+ * A sorted table is supplied with any wired entries at the beginning,
+ * followed by any global entries, and then finally regular entries.
+ * We start at the VPN and ASID values of zero and only assign user
+ * addresses, therefore guaranteeing no clash with addresses produced
+ * by UNIQUE_ENTRYHI.  We avoid any VPN values used by wired or global
+ * entries, by increasing the VPN value beyond the span of such entry.
+ *
+ * When a VPN/ASID clash is found with a regular entry we increment the
+ * ASID instead until no VPN/ASID clash has been found or the ASID space
+ * has been exhausted, in which case we increase the VPN value beyond
+ * the span of the largest clashing entry.
+ *
+ * We do not need to be concerned about FTLB or MMID configurations as
+ * those are required to implement the EHINV feature.
+ */
+static void __ref r4k_tlb_uniquify_write(struct tlbent *tlb_vpns, int tlbsize)
+{
+	unsigned long long asid, vpn, vpn_size, pagesz;
+	int widx, gidx, idx, sidx, lidx, i;
 
-	sort(tlb_vpns, cnt, sizeof(tlb_vpns[0]), r4k_vpn_cmp, NULL);
+	vpn_size = 1ULL << (current_cpu_data.vmbits - VPN2_SHIFT);
+	pagesz = ilog2((PM_4K >> VPN2_SHIFT) + 1);
 
-	write_c0_pagemask(PM_DEFAULT_MASK);
+	write_c0_pagemask(PM_4K);
 	write_c0_entrylo0(0);
 	write_c0_entrylo1(0);
 
-	idx = 0;
-	ent = tlbsize;
-	for (i = start; i < tlbsize; i++)
-		while (1) {
-			unsigned long entryhi, vpn;
+	asid = 0;
+	vpn = 0;
+	widx = 0;
+	gidx = 0;
+	for (sidx = 0; sidx < tlbsize && tlb_vpns[sidx].wired; sidx++)
+		;
+	for (lidx = sidx; lidx < tlbsize && tlb_vpns[lidx].global; lidx++)
+		;
+	idx = gidx = sidx + 1;
+	for (i = sidx; i < tlbsize; i++) {
+		unsigned long long entryhi, vpn_pagesz = 0;
 
-			entryhi = UNIQUE_ENTRYHI(ent);
-			vpn = entryhi & vpn_mask & PAGE_MASK;
+		while (1) {
+			if (WARN_ON(vpn >= vpn_size)) {
+				dump_tlb_all();
+				/* Pray local_flush_tlb_all() will cope.  */
+				return;
+			}
 
-			if (idx >= cnt || vpn < tlb_vpns[idx]) {
-				write_c0_entryhi(entryhi);
-				write_c0_index(i);
-				mtc0_tlbw_hazard();
-				tlb_write_indexed();
-				ent++;
-				break;
-			} else if (vpn == tlb_vpns[idx]) {
-				ent++;
-			} else {
+			/* VPN must be below the next wired entry.  */
+			if (widx < sidx && vpn >= tlb_vpns[widx].vpn) {
+				vpn = max(vpn,
+					  (tlb_vpns[widx].vpn +
+					   (1ULL << tlb_vpns[widx].pagesz)));
+				asid = 0;
+				widx++;
+				continue;
+			}
+			/* VPN must be below the next global entry.  */
+			if (gidx < lidx && vpn >= tlb_vpns[gidx].vpn) {
+				vpn = max(vpn,
+					  (tlb_vpns[gidx].vpn +
+					   (1ULL << tlb_vpns[gidx].pagesz)));
+				asid = 0;
+				gidx++;
+				continue;
+			}
+			/* Try to find a free ASID so as to conserve VPNs.  */
+			if (idx < tlbsize && vpn == tlb_vpns[idx].vpn &&
+			    asid == tlb_vpns[idx].asid) {
+				unsigned long long idx_pagesz;
+
+				idx_pagesz = tlb_vpns[idx].pagesz;
+				vpn_pagesz = max(vpn_pagesz, idx_pagesz);
+				do
+					idx++;
+				while (idx < tlbsize &&
+				       vpn == tlb_vpns[idx].vpn &&
+				       asid == tlb_vpns[idx].asid);
+				asid++;
+				if (asid > cpu_asid_mask(&current_cpu_data)) {
+					vpn += vpn_pagesz;
+					asid = 0;
+					vpn_pagesz = 0;
+				}
+				continue;
+			}
+			/* VPN mustn't be above the next regular entry.  */
+			if (idx < tlbsize && vpn > tlb_vpns[idx].vpn) {
+				vpn = max(vpn,
+					  (tlb_vpns[idx].vpn +
+					   (1ULL << tlb_vpns[idx].pagesz)));
+				asid = 0;
 				idx++;
+				continue;
 			}
+			break;
 		}
 
+		entryhi = (vpn << VPN2_SHIFT) | asid;
+		write_c0_entryhi_native(entryhi);
+		write_c0_index(tlb_vpns[i].index);
+		mtc0_tlbw_hazard();
+		tlb_write_indexed();
+
+		tlb_vpns[i].asid = asid;
+		tlb_vpns[i].vpn = vpn;
+		tlb_vpns[i].pagesz = pagesz;
+
+		asid++;
+		if (asid > cpu_asid_mask(&current_cpu_data)) {
+			vpn += 1ULL << pagesz;
+			asid = 0;
+		}
+	}
+}
+
+/*
+ * Initialise all TLB entries with unique values that do not clash with
+ * what we have been handed over and what we'll be using ourselves.
+ */
+static void __ref r4k_tlb_uniquify(void)
+{
+	int tlbsize = current_cpu_data.tlbsize;
+	bool use_slab = slab_is_available();
+	phys_addr_t tlb_vpn_size;
+	struct tlbent *tlb_vpns;
+
+	tlb_vpn_size = tlbsize * sizeof(*tlb_vpns);
+	tlb_vpns = (use_slab ?
+		    kmalloc(tlb_vpn_size, GFP_ATOMIC) :
+		    memblock_alloc_raw(tlb_vpn_size, sizeof(*tlb_vpns)));
+	if (WARN_ON(!tlb_vpns))
+		return; /* Pray local_flush_tlb_all() is good enough. */
+
+	htw_stop();
+
+	r4k_tlb_uniquify_read(tlb_vpns, tlbsize);
+
+	sort(tlb_vpns, tlbsize, sizeof(*tlb_vpns), r4k_entry_cmp, NULL);
+
+	r4k_tlb_uniquify_write(tlb_vpns, tlbsize);
+
+	write_c0_pagemask(PM_DEFAULT_MASK);
+
 	tlbw_use_hazard();
 	htw_start();
 	flush_micro_tlb();
@@ -640,7 +814,8 @@ static void r4k_tlb_configure(void)
 	temp_tlb_entry = current_cpu_data.tlbsize - 1;
 
 	/* From this point on the ARC firmware is dead.	 */
-	r4k_tlb_uniquify();
+	if (!cpu_has_tlbinv)
+		r4k_tlb_uniquify();
 	local_flush_tlb_all();
 
 	/* Did I tell you that ARC SUCKS?  */
diff --git a/arch/mips/ralink/clk.c b/arch/mips/ralink/clk.c
index 9db73fc..5c1eb46 100644
--- a/arch/mips/ralink/clk.c
+++ b/arch/mips/ralink/clk.c
@@ -21,16 +21,16 @@ static const char *clk_cpu(int *idx)
 {
 	switch (ralink_soc) {
 	case RT2880_SOC:
-		*idx = 0;
+		*idx = 1;
 		return "ralink,rt2880-sysc";
 	case RT3883_SOC:
-		*idx = 0;
+		*idx = 1;
 		return "ralink,rt3883-sysc";
 	case RT305X_SOC_RT3050:
-		*idx = 0;
+		*idx = 1;
 		return "ralink,rt3050-sysc";
 	case RT305X_SOC_RT3052:
-		*idx = 0;
+		*idx = 1;
 		return "ralink,rt3052-sysc";
 	case RT305X_SOC_RT3350:
 		*idx = 1;
