From: Jarod Wilson <jwilson@redhat.com>
Date: Tue, 7 Aug 2007 11:59:35 -0400
Subject: [ia64] validate and remap mmap requests
Message-id: 46B896E7.8020308@redhat.com
O-Subject: [RHEL5.1 PATCH 1/5] ia64: validate and remap mmap requests
Bugzilla: 240006

This is a multi-part message in MIME format.
Add initial support for ioremapping, backported from upstream kernel.

--
Jarod Wilson
jwilson@redhat.com

Acked-by: Steven Rostedt <srostedt@redhat.com>

diff --git a/include/linux/io.h b/include/linux/io.h
index c01f112..083ac88 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -19,6 +19,7 @@
 #define _LINUX_IO_H
 
 #include <asm/io.h>
+#include <asm/page.h>
 
 struct device;
 
@@ -51,4 +52,7 @@ void __iomem * devm_ioremap_nocache(struct device *dev, unsigned long offset,
 				    unsigned long size);
 void devm_iounmap(struct device *dev, void __iomem *addr);
 
+int ioremap_page_range(unsigned long addr, unsigned long end,
+		       unsigned long phys_addr, pgprot_t prot);
+
 #endif /* _LINUX_IO_H */
diff --git a/lib/Makefile b/lib/Makefile
index 51147da..575ee6c 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -7,6 +7,7 @@ lib-y := errno.o ctype.o string.o vsprintf.o cmdline.o \
 	 idr.o div64.o int_sqrt.o bitmap.o extable.o prio_tree.o \
 	 sha1.o
 
+lib-$(CONFIG_MMU) += ioremap.o
 lib-$(CONFIG_SMP) += cpumask.o
 
 lib-y	+= kobject.o kref.o kobject_uevent.o klist.o
diff --git a/lib/ioremap.c b/lib/ioremap.c
new file mode 100644
index 0000000..a9e4415
--- /dev/null
+++ b/lib/ioremap.c
@@ -0,0 +1,91 @@
+/*
+ * Re-map IO memory to kernel address space so that we can access it.
+ * This is needed for high PCI addresses that aren't mapped in the
+ * 640k-1MB IO memory area on PC's
+ *
+ * (C) Copyright 1995 1996 Linus Torvalds
+ */
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+
+#include <asm/cacheflush.h>
+#include <asm/pgtable.h>
+
+static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
+		unsigned long end, unsigned long phys_addr, pgprot_t prot)
+{
+	pte_t *pte;
+	unsigned long pfn;
+
+	pfn = phys_addr >> PAGE_SHIFT;
+	pte = pte_alloc_kernel(pmd, addr);
+	if (!pte)
+		return -ENOMEM;
+	do {
+		BUG_ON(!pte_none(*pte));
+		set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
+		pfn++;
+	} while (pte++, addr += PAGE_SIZE, addr != end);
+	return 0;
+}
+
+static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
+		unsigned long end, unsigned long phys_addr, pgprot_t prot)
+{
+	pmd_t *pmd;
+	unsigned long next;
+
+	phys_addr -= addr;
+	pmd = pmd_alloc(&init_mm, pud, addr);
+	if (!pmd)
+		return -ENOMEM;
+	do {
+		next = pmd_addr_end(addr, end);
+		if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, prot))
+			return -ENOMEM;
+	} while (pmd++, addr = next, addr != end);
+	return 0;
+}
+
+static inline int ioremap_pud_range(pgd_t *pgd, unsigned long addr,
+		unsigned long end, unsigned long phys_addr, pgprot_t prot)
+{
+	pud_t *pud;
+	unsigned long next;
+
+	phys_addr -= addr;
+	pud = pud_alloc(&init_mm, pgd, addr);
+	if (!pud)
+		return -ENOMEM;
+	do {
+		next = pud_addr_end(addr, end);
+		if (ioremap_pmd_range(pud, addr, next, phys_addr + addr, prot))
+			return -ENOMEM;
+	} while (pud++, addr = next, addr != end);
+	return 0;
+}
+
+int ioremap_page_range(unsigned long addr,
+		       unsigned long end, unsigned long phys_addr, pgprot_t prot)
+{
+	pgd_t *pgd;
+	unsigned long start;
+	unsigned long next;
+	int err;
+
+	BUG_ON(addr >= end);
+
+	start = addr;
+	phys_addr -= addr;
+	pgd = pgd_offset_k(addr);
+	do {
+		next = pgd_addr_end(addr, end);
+		err = ioremap_pud_range(pgd, addr, next, phys_addr+addr, prot);
+		if (err)
+			break;
+	} while (pgd++, addr = next, addr != end);
+
+	flush_cache_vmap(start, end);
+
+	return err;
+}