v4.19.13 snapshot.
diff --git a/arch/mips/mm/c-r3k.c b/arch/mips/mm/c-r3k.c
new file mode 100644
index 0000000..3466fcd
--- /dev/null
+++ b/arch/mips/mm/c-r3k.c
@@ -0,0 +1,349 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * r2300.c: R2000 and R3000 specific mmu/cache code.
+ *
+ * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
+ *
+ * with a lot of changes to make this thing work for R3000s
+ * Tx39XX R4k style caches added. HK
+ * Copyright (C) 1998, 1999, 2000 Harald Koerfgen
+ * Copyright (C) 1998 Gleb Raiko & Vladimir Roganov
+ * Copyright (C) 2001, 2004, 2007  Maciej W. Rozycki
+ */
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/smp.h>
+#include <linux/mm.h>
+
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/mmu_context.h>
+#include <asm/isadep.h>
+#include <asm/io.h>
+#include <asm/bootinfo.h>
+#include <asm/cpu.h>
+
+static unsigned long icache_size, dcache_size;		/* Size in bytes */
+static unsigned long icache_lsize, dcache_lsize;	/* Size in bytes */
+
+unsigned long r3k_cache_size(unsigned long ca_flags)
+{
+	unsigned long flags, status, dummy, size;
+	volatile unsigned long *p;
+
+	p = (volatile unsigned long *) KSEG0;
+
+	flags = read_c0_status();
+
+	/* isolate cache space */
+	write_c0_status((ca_flags|flags)&~ST0_IEC);
+
+	*p = 0xa5a55a5a;
+	dummy = *p;
+	status = read_c0_status();
+
+	if (dummy != 0xa5a55a5a || (status & ST0_CM)) {
+		size = 0;
+	} else {
+		for (size = 128; size <= 0x40000; size <<= 1)
+			*(p + size) = 0;
+		*p = -1;
+		for (size = 128;
+		     (size <= 0x40000) && (*(p + size) == 0);
+		     size <<= 1)
+			;
+		if (size > 0x40000)
+			size = 0;
+	}
+
+	write_c0_status(flags);
+
+	return size * sizeof(*p);
+}
+
+unsigned long r3k_cache_lsize(unsigned long ca_flags)
+{
+	unsigned long flags, status, lsize, i;
+	volatile unsigned long *p;
+
+	p = (volatile unsigned long *) KSEG0;
+
+	flags = read_c0_status();
+
+	/* isolate cache space */
+	write_c0_status((ca_flags|flags)&~ST0_IEC);
+
+	for (i = 0; i < 128; i++)
+		*(p + i) = 0;
+	*(volatile unsigned char *)p = 0;
+	for (lsize = 1; lsize < 128; lsize <<= 1) {
+		*(p + lsize);
+		status = read_c0_status();
+		if (!(status & ST0_CM))
+			break;
+	}
+	for (i = 0; i < 128; i += lsize)
+		*(volatile unsigned char *)(p + i) = 0;
+
+	write_c0_status(flags);
+
+	return lsize * sizeof(*p);
+}
+
+static void r3k_probe_cache(void)
+{
+	dcache_size = r3k_cache_size(ST0_ISC);
+	if (dcache_size)
+		dcache_lsize = r3k_cache_lsize(ST0_ISC);
+
+	icache_size = r3k_cache_size(ST0_ISC|ST0_SWC);
+	if (icache_size)
+		icache_lsize = r3k_cache_lsize(ST0_ISC|ST0_SWC);
+}
+
+static void r3k_flush_icache_range(unsigned long start, unsigned long end)
+{
+	unsigned long size, i, flags;
+	volatile unsigned char *p;
+
+	size = end - start;
+	if (size > icache_size || KSEGX(start) != KSEG0) {
+		start = KSEG0;
+		size = icache_size;
+	}
+	p = (char *)start;
+
+	flags = read_c0_status();
+
+	/* isolate cache space */
+	write_c0_status((ST0_ISC|ST0_SWC|flags)&~ST0_IEC);
+
+	for (i = 0; i < size; i += 0x080) {
+		asm(	"sb\t$0, 0x000(%0)\n\t"
+			"sb\t$0, 0x004(%0)\n\t"
+			"sb\t$0, 0x008(%0)\n\t"
+			"sb\t$0, 0x00c(%0)\n\t"
+			"sb\t$0, 0x010(%0)\n\t"
+			"sb\t$0, 0x014(%0)\n\t"
+			"sb\t$0, 0x018(%0)\n\t"
+			"sb\t$0, 0x01c(%0)\n\t"
+			"sb\t$0, 0x020(%0)\n\t"
+			"sb\t$0, 0x024(%0)\n\t"
+			"sb\t$0, 0x028(%0)\n\t"
+			"sb\t$0, 0x02c(%0)\n\t"
+			"sb\t$0, 0x030(%0)\n\t"
+			"sb\t$0, 0x034(%0)\n\t"
+			"sb\t$0, 0x038(%0)\n\t"
+			"sb\t$0, 0x03c(%0)\n\t"
+			"sb\t$0, 0x040(%0)\n\t"
+			"sb\t$0, 0x044(%0)\n\t"
+			"sb\t$0, 0x048(%0)\n\t"
+			"sb\t$0, 0x04c(%0)\n\t"
+			"sb\t$0, 0x050(%0)\n\t"
+			"sb\t$0, 0x054(%0)\n\t"
+			"sb\t$0, 0x058(%0)\n\t"
+			"sb\t$0, 0x05c(%0)\n\t"
+			"sb\t$0, 0x060(%0)\n\t"
+			"sb\t$0, 0x064(%0)\n\t"
+			"sb\t$0, 0x068(%0)\n\t"
+			"sb\t$0, 0x06c(%0)\n\t"
+			"sb\t$0, 0x070(%0)\n\t"
+			"sb\t$0, 0x074(%0)\n\t"
+			"sb\t$0, 0x078(%0)\n\t"
+			"sb\t$0, 0x07c(%0)\n\t"
+			: : "r" (p) );
+		p += 0x080;
+	}
+
+	write_c0_status(flags);
+}
+
+static void r3k_flush_dcache_range(unsigned long start, unsigned long end)
+{
+	unsigned long size, i, flags;
+	volatile unsigned char *p;
+
+	size = end - start;
+	if (size > dcache_size || KSEGX(start) != KSEG0) {
+		start = KSEG0;
+		size = dcache_size;
+	}
+	p = (char *)start;
+
+	flags = read_c0_status();
+
+	/* isolate cache space */
+	write_c0_status((ST0_ISC|flags)&~ST0_IEC);
+
+	for (i = 0; i < size; i += 0x080) {
+		asm(	"sb\t$0, 0x000(%0)\n\t"
+			"sb\t$0, 0x004(%0)\n\t"
+			"sb\t$0, 0x008(%0)\n\t"
+			"sb\t$0, 0x00c(%0)\n\t"
+			"sb\t$0, 0x010(%0)\n\t"
+			"sb\t$0, 0x014(%0)\n\t"
+			"sb\t$0, 0x018(%0)\n\t"
+			"sb\t$0, 0x01c(%0)\n\t"
+			"sb\t$0, 0x020(%0)\n\t"
+			"sb\t$0, 0x024(%0)\n\t"
+			"sb\t$0, 0x028(%0)\n\t"
+			"sb\t$0, 0x02c(%0)\n\t"
+			"sb\t$0, 0x030(%0)\n\t"
+			"sb\t$0, 0x034(%0)\n\t"
+			"sb\t$0, 0x038(%0)\n\t"
+			"sb\t$0, 0x03c(%0)\n\t"
+			"sb\t$0, 0x040(%0)\n\t"
+			"sb\t$0, 0x044(%0)\n\t"
+			"sb\t$0, 0x048(%0)\n\t"
+			"sb\t$0, 0x04c(%0)\n\t"
+			"sb\t$0, 0x050(%0)\n\t"
+			"sb\t$0, 0x054(%0)\n\t"
+			"sb\t$0, 0x058(%0)\n\t"
+			"sb\t$0, 0x05c(%0)\n\t"
+			"sb\t$0, 0x060(%0)\n\t"
+			"sb\t$0, 0x064(%0)\n\t"
+			"sb\t$0, 0x068(%0)\n\t"
+			"sb\t$0, 0x06c(%0)\n\t"
+			"sb\t$0, 0x070(%0)\n\t"
+			"sb\t$0, 0x074(%0)\n\t"
+			"sb\t$0, 0x078(%0)\n\t"
+			"sb\t$0, 0x07c(%0)\n\t"
+			: : "r" (p) );
+		p += 0x080;
+	}
+
+	write_c0_status(flags);
+}
+
+static inline void r3k_flush_cache_all(void)
+{
+}
+
+static inline void r3k___flush_cache_all(void)
+{
+	r3k_flush_dcache_range(KSEG0, KSEG0 + dcache_size);
+	r3k_flush_icache_range(KSEG0, KSEG0 + icache_size);
+}
+
+static void r3k_flush_cache_mm(struct mm_struct *mm)
+{
+}
+
+static void r3k_flush_cache_range(struct vm_area_struct *vma,
+				  unsigned long start, unsigned long end)
+{
+}
+
+static void r3k_flush_cache_page(struct vm_area_struct *vma,
+				 unsigned long addr, unsigned long pfn)
+{
+	unsigned long kaddr = KSEG0ADDR(pfn << PAGE_SHIFT);
+	int exec = vma->vm_flags & VM_EXEC;
+	struct mm_struct *mm = vma->vm_mm;
+	pgd_t *pgdp;
+	pud_t *pudp;
+	pmd_t *pmdp;
+	pte_t *ptep;
+
+	pr_debug("cpage[%08lx,%08lx]\n",
+		 cpu_context(smp_processor_id(), mm), addr);
+
+	/* No ASID => no such page in the cache.  */
+	if (cpu_context(smp_processor_id(), mm) == 0)
+		return;
+
+	pgdp = pgd_offset(mm, addr);
+	pudp = pud_offset(pgdp, addr);
+	pmdp = pmd_offset(pudp, addr);
+	ptep = pte_offset(pmdp, addr);
+
+	/* Invalid => no such page in the cache.  */
+	if (!(pte_val(*ptep) & _PAGE_PRESENT))
+		return;
+
+	r3k_flush_dcache_range(kaddr, kaddr + PAGE_SIZE);
+	if (exec)
+		r3k_flush_icache_range(kaddr, kaddr + PAGE_SIZE);
+}
+
+static void local_r3k_flush_data_cache_page(void *addr)
+{
+}
+
+static void r3k_flush_data_cache_page(unsigned long addr)
+{
+}
+
+static void r3k_flush_cache_sigtramp(unsigned long addr)
+{
+	unsigned long flags;
+
+	pr_debug("csigtramp[%08lx]\n", addr);
+
+	flags = read_c0_status();
+
+	write_c0_status(flags&~ST0_IEC);
+
+	/* Fill the TLB to avoid an exception with caches isolated. */
+	asm(	"lw\t$0, 0x000(%0)\n\t"
+		"lw\t$0, 0x004(%0)\n\t"
+		: : "r" (addr) );
+
+	write_c0_status((ST0_ISC|ST0_SWC|flags)&~ST0_IEC);
+
+	asm(	"sb\t$0, 0x000(%0)\n\t"
+		"sb\t$0, 0x004(%0)\n\t"
+		: : "r" (addr) );
+
+	write_c0_status(flags);
+}
+
+static void r3k_flush_kernel_vmap_range(unsigned long vaddr, int size)
+{
+	BUG();
+}
+
+static void r3k_dma_cache_wback_inv(unsigned long start, unsigned long size)
+{
+	/* Catch bad driver code */
+	BUG_ON(size == 0);
+
+	iob();
+	r3k_flush_dcache_range(start, start + size);
+}
+
+void r3k_cache_init(void)
+{
+	extern void build_clear_page(void);
+	extern void build_copy_page(void);
+
+	r3k_probe_cache();
+
+	flush_cache_all = r3k_flush_cache_all;
+	__flush_cache_all = r3k___flush_cache_all;
+	flush_cache_mm = r3k_flush_cache_mm;
+	flush_cache_range = r3k_flush_cache_range;
+	flush_cache_page = r3k_flush_cache_page;
+	flush_icache_range = r3k_flush_icache_range;
+	local_flush_icache_range = r3k_flush_icache_range;
+	__flush_icache_user_range = r3k_flush_icache_range;
+	__local_flush_icache_user_range = r3k_flush_icache_range;
+
+	__flush_kernel_vmap_range = r3k_flush_kernel_vmap_range;
+
+	flush_cache_sigtramp = r3k_flush_cache_sigtramp;
+	local_flush_data_cache_page = local_r3k_flush_data_cache_page;
+	flush_data_cache_page = r3k_flush_data_cache_page;
+
+	_dma_cache_wback_inv = r3k_dma_cache_wback_inv;
+	_dma_cache_wback = r3k_dma_cache_wback_inv;
+	_dma_cache_inv = r3k_dma_cache_wback_inv;
+
+	printk("Primary instruction cache %ldkB, linesize %ld bytes.\n",
+		icache_size >> 10, icache_lsize);
+	printk("Primary data cache %ldkB, linesize %ld bytes.\n",
+		dcache_size >> 10, dcache_lsize);
+
+	build_clear_page();
+	build_copy_page();
+}