v4.19.13 snapshot.
diff --git a/arch/mips/mm/ioremap.c b/arch/mips/mm/ioremap.c
new file mode 100644
index 0000000..1601d90
--- /dev/null
+++ b/arch/mips/mm/ioremap.c
@@ -0,0 +1,206 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * (C) Copyright 1995 1996 Linus Torvalds
+ * (C) Copyright 2001, 2002 Ralf Baechle
+ */
+#include <linux/export.h>
+#include <asm/addrspace.h>
+#include <asm/byteorder.h>
+#include <linux/ioport.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/mm_types.h>
+#include <asm/cacheflush.h>
+#include <asm/io.h>
+#include <asm/tlbflush.h>
+
+static inline void remap_area_pte(pte_t * pte, unsigned long address,
+ phys_addr_t size, phys_addr_t phys_addr, unsigned long flags)
+{
+ phys_addr_t end;
+ unsigned long pfn;
+ pgprot_t pgprot = __pgprot(_PAGE_GLOBAL | _PAGE_PRESENT | __READABLE
+ | __WRITEABLE | flags);
+
+ address &= ~PMD_MASK;
+ end = address + size;
+ if (end > PMD_SIZE)
+ end = PMD_SIZE;
+ BUG_ON(address >= end);
+ pfn = phys_addr >> PAGE_SHIFT;
+ do {
+ if (!pte_none(*pte)) {
+ printk("remap_area_pte: page already exists\n");
+ BUG();
+ }
+ set_pte(pte, pfn_pte(pfn, pgprot));
+ address += PAGE_SIZE;
+ pfn++;
+ pte++;
+ } while (address && (address < end));
+}
+
+static inline int remap_area_pmd(pmd_t * pmd, unsigned long address,
+ phys_addr_t size, phys_addr_t phys_addr, unsigned long flags)
+{
+ phys_addr_t end;
+
+ address &= ~PGDIR_MASK;
+ end = address + size;
+ if (end > PGDIR_SIZE)
+ end = PGDIR_SIZE;
+ phys_addr -= address;
+ BUG_ON(address >= end);
+ do {
+ pte_t * pte = pte_alloc_kernel(pmd, address);
+ if (!pte)
+ return -ENOMEM;
+ remap_area_pte(pte, address, end - address, address + phys_addr, flags);
+ address = (address + PMD_SIZE) & PMD_MASK;
+ pmd++;
+ } while (address && (address < end));
+ return 0;
+}
+
+static int remap_area_pages(unsigned long address, phys_addr_t phys_addr,
+ phys_addr_t size, unsigned long flags)
+{
+ int error;
+ pgd_t * dir;
+ unsigned long end = address + size;
+
+ phys_addr -= address;
+ dir = pgd_offset(&init_mm, address);
+ flush_cache_all();
+ BUG_ON(address >= end);
+ do {
+ pud_t *pud;
+ pmd_t *pmd;
+
+ error = -ENOMEM;
+ pud = pud_alloc(&init_mm, dir, address);
+ if (!pud)
+ break;
+ pmd = pmd_alloc(&init_mm, pud, address);
+ if (!pmd)
+ break;
+ if (remap_area_pmd(pmd, address, end - address,
+ phys_addr + address, flags))
+ break;
+ error = 0;
+ address = (address + PGDIR_SIZE) & PGDIR_MASK;
+ dir++;
+ } while (address && (address < end));
+ flush_tlb_all();
+ return error;
+}
+
+static int __ioremap_check_ram(unsigned long start_pfn, unsigned long nr_pages,
+ void *arg)
+{
+ unsigned long i;
+
+ for (i = 0; i < nr_pages; i++) {
+ if (pfn_valid(start_pfn + i) &&
+ !PageReserved(pfn_to_page(start_pfn + i)))
+ return 1;
+ }
+
+ return 0;
+}
+
+/*
+ * Generic mapping function (not visible outside):
+ */
+
+/*
+ * Remap an arbitrary physical address space into the kernel virtual
+ * address space. Needed when the kernel wants to access high addresses
+ * directly.
+ *
+ * NOTE! We need to allow non-page-aligned mappings too: we will obviously
+ * have to convert them into an offset in a page-aligned mapping, but the
+ * caller shouldn't need to know that small detail.
+ */
+
+#define IS_LOW512(addr) (!((phys_addr_t)(addr) & (phys_addr_t) ~0x1fffffffULL))
+
+void __iomem * __ioremap(phys_addr_t phys_addr, phys_addr_t size, unsigned long flags)
+{
+ unsigned long offset, pfn, last_pfn;
+ struct vm_struct * area;
+ phys_addr_t last_addr;
+ void * addr;
+
+ phys_addr = fixup_bigphys_addr(phys_addr, size);
+
+ /* Don't allow wraparound or zero size */
+ last_addr = phys_addr + size - 1;
+ if (!size || last_addr < phys_addr)
+ return NULL;
+
+ /*
+ * Map uncached objects in the low 512mb of address space using KSEG1,
+ * otherwise map using page tables.
+ */
+ if (IS_LOW512(phys_addr) && IS_LOW512(last_addr) &&
+ flags == _CACHE_UNCACHED)
+ return (void __iomem *) CKSEG1ADDR(phys_addr);
+
+ /*
+ * Don't allow anybody to remap RAM that may be allocated by the page
+ * allocator, since that could lead to races & data clobbering.
+ */
+ pfn = PFN_DOWN(phys_addr);
+ last_pfn = PFN_DOWN(last_addr);
+ if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL,
+ __ioremap_check_ram) == 1) {
+ WARN_ONCE(1, "ioremap on RAM at %pa - %pa\n",
+ &phys_addr, &last_addr);
+ return NULL;
+ }
+
+ /*
+ * Mappings have to be page-aligned
+ */
+ offset = phys_addr & ~PAGE_MASK;
+ phys_addr &= PAGE_MASK;
+ size = PAGE_ALIGN(last_addr + 1) - phys_addr;
+
+ /*
+ * Ok, go for it..
+ */
+ area = get_vm_area(size, VM_IOREMAP);
+ if (!area)
+ return NULL;
+ addr = area->addr;
+ if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) {
+ vunmap(addr);
+ return NULL;
+ }
+
+ return (void __iomem *) (offset + (char *)addr);
+}
+
+#define IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1)
+
+void __iounmap(const volatile void __iomem *addr)
+{
+ struct vm_struct *p;
+
+ if (IS_KSEG1(addr))
+ return;
+
+ p = remove_vm_area((void *) (PAGE_MASK & (unsigned long __force) addr));
+ if (!p)
+ printk(KERN_ERR "iounmap: bad address %p\n", addr);
+
+ kfree(p);
+}
+
+EXPORT_SYMBOL(__ioremap);
+EXPORT_SYMBOL(__iounmap);