File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/m68k/sun3/dvma.c b/arch/m68k/sun3/dvma.c
new file mode 100644
index 0000000..d95506e
--- /dev/null
+++ b/arch/m68k/sun3/dvma.c
@@ -0,0 +1,69 @@
+/*
+ * linux/arch/m68k/sun3/dvma.c
+ *
+ * Written by Sam Creasey
+ *
+ * Sun3 IOMMU routines used for dvma accesses.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/bootmem.h>
+#include <linux/list.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/sun3mmu.h>
+#include <asm/dvma.h>
+
+
+static unsigned long ptelist[120];
+
+static unsigned long dvma_page(unsigned long kaddr, unsigned long vaddr)
+{
+	unsigned long pte;
+	unsigned long j;
+	pte_t ptep;
+
+	j = *(volatile unsigned long *)kaddr;
+	*(volatile unsigned long *)kaddr = j;
+
+	ptep = pfn_pte(virt_to_pfn(kaddr), PAGE_KERNEL);
+	pte = pte_val(ptep);
+//		printk("dvma_remap: addr %lx -> %lx pte %08lx len %x\n",
+//		       kaddr, vaddr, pte, len);
+	if(ptelist[(vaddr & 0xff000) >> PAGE_SHIFT] != pte) {
+		sun3_put_pte(vaddr, pte);
+		ptelist[(vaddr & 0xff000) >> PAGE_SHIFT] = pte;
+	}
+
+	return (vaddr + (kaddr & ~PAGE_MASK));
+
+}
+
+int dvma_map_iommu(unsigned long kaddr, unsigned long baddr,
+			      int len)
+{
+
+	unsigned long end;
+	unsigned long vaddr;
+
+	vaddr = dvma_btov(baddr);
+
+	end = vaddr + len;
+
+	while(vaddr < end) {
+		dvma_page(kaddr, vaddr);
+		kaddr += PAGE_SIZE;
+		vaddr += PAGE_SIZE;
+	}
+
+	return 0;
+
+}
+
+void __init sun3_dvma_init(void)
+{
+	memset(ptelist, 0, sizeof(ptelist));
+}