[git pull] x86 PAT changes

Ingo Molnar
2008-04-24T22:56:50Z

Linus, please pull the x86-pat git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86-pat.git for-linus

this adds the second (and final) phase of the x86 PAT changes. Due to
generic impact (the drivers/char/mem.c and include/asm-generic/iomap.h
changes) this is offered as a separate tree.

The new CONFIG_NONPROMISC_DEVMEM defaults to disabled so PAT will be
disabled, to stay compatible and to be a bit cautious/gradual.

Thanks,

Ingo

------------------>
Arjan van de Ven (1):
x86: introduce /dev/mem restrictions with a config option

Ingo Molnar (2):
pat: cleanups
/dev/mem: make promisc the default

Venki Pallipadi (1):
devmem: add range_is_allowed() check to mmap of /dev/mem

venkatesh.pallipadi@intel.com (4):
x86: PAT avoid aliasing in /dev/mem read/write
x86: PAT phys_mem_access_prot_allowed for dev/mem mmap
x86: PAT use reserve free memtype in mmap of /dev/mem
generic: add ioremap_wc() interface wrapper

arch/x86/Kconfig.debug | 11 +++
arch/x86/mm/init_32.c | 19 +++++
arch/x86/mm/init_64.c | 20 +++++
arch/x86/mm/ioremap.c | 29 +++++++
arch/x86/mm/pat.c | 175 +++++++++++++++++++++++++++++++++++++++----
drivers/char/mem.c | 133 +++++++++++++++++++++++++--------
include/asm-generic/iomap.h | 4 +
include/asm-x86/io.h | 8 ++
include/asm-x86/io_32.h | 6 --
include/asm-x86/io_64.h | 6 --
include/asm-x86/page.h | 1 +
include/asm-x86/pgtable.h | 9 ++
12 files changed, 363 insertions(+), 58 deletions(-)

diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index 610aaec..239fd9f 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -5,6 +5,17 @@ config TRACE_IRQFLAGS_SUPPORT

source "lib/Kconfig.debug"

+config NONPROMISC_DEVMEM
+ bool "Disable promiscuous /dev/mem"
+ help
+ The /dev/mem file by default only allows userspace access to PCI
+ space and the BIOS code and data regions. This is sufficient for
+ dosemu and X and all common users of /dev/mem. With this config
+ option, you allow userspace access to all of memory, including
+ kernel and userspace memory. Accidental access to this is
+ obviously disasterous, but specific access can be used by people
+ debugging the kernel.
+
config EARLY_PRINTK
bool "Early printk" if EMBEDDED
default y
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 9ec62da..39852d5 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -227,6 +227,25 @@ static inline int page_kills_ppro(unsigned long pagenr)
return 0;
}

+/*
+ * devmem_is_allowed() checks to see if /dev/mem access to a certain address
+ * is valid. The argument is a physical page number.
+ *
+ *
+ * On x86, access has to be given to the first megabyte of ram because that area
+ * contains bios code and data regions used by X and dosemu and similar apps.
+ * Access has to be given to non-kernel-ram areas as well, these contain the PCI
+ * mmio resources as well as potential bios/acpi data regions.
+ */
+int devmem_is_allowed(unsigned long pagenr)
+{
+ if (pagenr <= 256)
+ return 1;
+ if (!page_is_ram(pagenr))
+ return 1;
+ return 0;
+}
+
#ifdef CONFIG_HIGHMEM
pte_t *kmap_pte;
pgprot_t kmap_prot;
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 1ff7906..49c274e 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -664,6 +664,26 @@ EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);

#endif /* CONFIG_MEMORY_HOTPLUG */

+/*
+ * devmem_is_allowed() checks to see if /dev/mem access to a certain address
+ * is valid. The argument is a physical page number.
+ *
+ *
+ * On x86, access has to be given to the first megabyte of ram because that area
+ * contains bios code and data regions used by X and dosemu and similar apps.
+ * Access has to be given to non-kernel-ram areas as well, these contain the PCI
+ * mmio resources as well as potential bios/acpi data regions.
+ */
+int devmem_is_allowed(unsigned long pagenr)
+{
+ if (pagenr <= 256)
+ return 1;
+ if (!page_is_ram(pagenr))
+ return 1;
+ return 0;
+}
+
+
static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel,
kcore_modules, kcore_vsyscall;

diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 3a4baf9..caac7d5 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -336,6 +336,35 @@ void iounmap(volatile void __iomem *addr)
}
EXPORT_SYMBOL(iounmap);

+/*
+ * Convert a physical pointer to a virtual kernel pointer for /dev/mem
+ * access
+ */
+void *xlate_dev_mem_ptr(unsigned long phys)
+{
+ void *addr;
+ unsigned long start = phys & PAGE_MASK;
+
+ /* If page is RAM, we can use __va. Otherwise ioremap and unmap. */
+ if (page_is_ram(start >> PAGE_SHIFT))
+ return __va(phys);
+
+ addr = (void *)ioremap(start, PAGE_SIZE);
+ if (addr)
+ addr = (void *)((unsigned long)addr | (phys & ~PAGE_MASK));
+
+ return addr;
+}
+
+void unxlate_dev_mem_ptr(unsigned long phys, void *addr)
+{
+ if (page_is_ram(phys >> PAGE_SHIFT))
+ return;
+
+ iounmap((void __iomem *)((unsigned long)addr & PAGE_MASK));
+ return;
+}
+
#ifdef CONFIG_X86_32

int __initdata early_ioremap_debug;
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 72c0f60..ef8b64b 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -11,6 +11,7 @@
#include <linux/kernel.h>
#include <linux/gfp.h>
#include <linux/fs.h>
+#include <linux/bootmem.h>

#include <asm/msr.h>
#include <asm/tlbflush.h>
@@ -21,6 +22,7 @@
#include <asm/cacheflush.h>
#include <asm/fcntl.h>
#include <asm/mtrr.h>
+#include <asm/io.h>

int pat_wc_enabled = 1;

@@ -190,6 +192,21 @@ static int pat_x_mtrr_type(u64 start, u64 end, unsigned long prot,
return 0;
}

+/*
+ * req_type typically has one of the:
+ * - _PAGE_CACHE_WB
+ * - _PAGE_CACHE_WC
+ * - _PAGE_CACHE_UC_MINUS
+ * - _PAGE_CACHE_UC
+ *
+ * req_type will have a special case value '-1', when requester want to inherit
+ * the memory type from mtrr (if WB), existing PAT, defaulting to UC_MINUS.
+ *
+ * If ret_type is NULL, function will return an error if it cannot reserve the
+ * region with req_type. If ret_type is non-null, function will return
+ * available type in ret_type in case of no error. In case of any error
+ * it will return a negative return value.
+ */
int reserve_memtype(u64 start, u64 end, unsigned long req_type,
unsigned long *ret_type)
{
@@ -200,9 +217,14 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,

/* Only track when pat_wc_enabled */
if (!pat_wc_enabled) {
- if (ret_type)
- *ret_type = req_type;
-
+ /* This is identical to page table setting without PAT */
+ if (ret_type) {
+ if (req_type == -1) {
+ *ret_type = _PAGE_CACHE_WB;
+ } else {
+ *ret_type = req_type;
+ }
+ }
return 0;
}

@@ -214,8 +236,29 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
return 0;
}

- req_type &= _PAGE_CACHE_MASK;
- err = pat_x_mtrr_type(start, end, req_type, &actual_type);
+ if (req_type == -1) {
+ /*
+ * Special case where caller wants to inherit from mtrr or
+ * existing pat mapping, defaulting to UC_MINUS in case of
+ * no match.
+ */
+ u8 mtrr_type = mtrr_type_lookup(start, end);
+ if (mtrr_type == 0xFE) { /* MTRR match error */
+ err = -1;
+ }
+
+ if (mtrr_type == MTRR_TYPE_WRBACK) {
+ req_type = _PAGE_CACHE_WB;
+ actual_type = _PAGE_CACHE_WB;
+ } else {
+ req_type = _PAGE_CACHE_UC_MINUS;
+ actual_type = _PAGE_CACHE_UC_MINUS;
+ }
+ } else {
+ req_type &= _PAGE_CACHE_MASK;
+ err = pat_x_mtrr_type(start, end, req_type, &actual_type);
+ }
+
if (err) {
if (ret_type)
*ret_type = actual_type;
@@ -241,7 +284,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
struct memtype *saved_ptr;

if (parse->start >= end) {
- printk("New Entry\n");
+ pr_debug("New Entry\n");
list_add(&new_entry->nd, parse->nd.prev);
new_entry = NULL;
break;
@@ -343,7 +386,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
break;
}

- printk("Overlap at 0x%Lx-0x%Lx\n",
+ printk(KERN_INFO "Overlap at 0x%Lx-0x%Lx\n",
saved_ptr->start, saved_ptr->end);
/* No conflict. Go ahead and add this new entry */
list_add(&new_entry->nd, &saved_ptr->nd);
@@ -353,7 +396,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
}

if (err) {
- printk(
+ printk(KERN_INFO
"reserve_memtype failed 0x%Lx-0x%Lx, track %s, req %s\n",
start, end, cattr_name(new_entry->type),
cattr_name(req_type));
@@ -365,16 +408,16 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
if (new_entry) {
/* No conflict. Not yet added to the list. Add to the tail */
list_add_tail(&new_entry->nd, &memtype_list);
- printk("New Entry\n");
- }
+ pr_debug("New Entry\n");
+ }

if (ret_type) {
- printk(
+ pr_debug(
"reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s, ret %s\n",
start, end, cattr_name(actual_type),
cattr_name(req_type), cattr_name(*ret_type));
} else {
- printk(
+ pr_debug(
"reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s\n",
start, end, cattr_name(actual_type),
cattr_name(req_type));
@@ -411,11 +454,115 @@ int free_memtype(u64 start, u64 end)
spin_unlock(&memtype_lock);

if (err) {
- printk(KERN_DEBUG "%s:%d freeing invalid memtype %Lx-%Lx\n",
+ printk(KERN_INFO "%s:%d freeing invalid memtype %Lx-%Lx\n",
current->comm, current->pid, start, end);
}

- printk( "free_memtype request 0x%Lx-0x%Lx\n", start, end);
+ pr_debug("free_memtype request 0x%Lx-0x%Lx\n", start, end);
return err;
}

+
+/*
+ * /dev/mem mmap interface. The memtype used for mapping varies:
+ * - Use UC for mappings with O_SYNC flag
+ * - Without O_SYNC flag, if there is any conflict in reserve_memtype,
+ * inherit the memtype from existing mapping.
+ * - Else use UC_MINUS memtype (for backward compatibility with existing
+ * X drivers.
+ */
+pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
+ unsigned long size, pgprot_t vma_prot)
+{
+ return vma_prot;
+}
+
+int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
+ unsigned long size, pgprot_t *vma_prot)
+{
+ u64 offset = ((u64) pfn) << PAGE_SHIFT;
+ unsigned long flags = _PAGE_CACHE_UC_MINUS;
+ unsigned long ret_flags;
+ int retval;
+
+ if (file->f_flags & O_SYNC) {
+ flags = _PAGE_CACHE_UC;
+ }
+
+#ifdef CONFIG_X86_32
+ /*
+ * On the PPro and successors, the MTRRs are used to set
+ * memory types for physical addresses outside main memory,
+ * so blindly setting UC or PWT on those pages is wrong.
+ * For Pentiums and earlier, the surround logic should disable
+ * caching for the high addresses through the KEN pin, but
+ * we maintain the tradition of paranoia in this code.
+ */
+ if (!pat_wc_enabled &&
+ ! ( test_bit(X86_FEATURE_MTRR, boot_cpu_data.x86_capability) ||
+ test_bit(X86_FEATURE_K6_MTRR, boot_cpu_data.x86_capability) ||
+ test_bit(X86_FEATURE_CYRIX_ARR, boot_cpu_data.x86_capability) ||
+ test_bit(X86_FEATURE_CENTAUR_MCR, boot_cpu_data.x86_capability)) &&
+ (pfn << PAGE_SHIFT) >= __pa(high_memory)) {
+ flags = _PAGE_CACHE_UC;
+ }
+#endif
+
+ /*
+ * With O_SYNC, we can only take UC mapping. Fail if we cannot.
+ * Without O_SYNC, we want to get
+ * - WB for WB-able memory and no other conflicting mappings
+ * - UC_MINUS for non-WB-able memory with no other conflicting mappings
+ * - Inherit from confliting mappings otherwise
+ */
+ if (flags != _PAGE_CACHE_UC_MINUS) {
+ retval = reserve_memtype(offset, offset + size, flags, NULL);
+ } else {
+ retval = reserve_memtype(offset, offset + size, -1, &ret_flags);
+ }
+
+ if (retval < 0)
+ return 0;
+
+ flags = ret_flags;
+
+ if (pfn <= max_pfn_mapped &&
+ ioremap_change_attr((unsigned long)__va(offset), size, flags) < 0) {
+ free_memtype(offset, offset + size);
+ printk(KERN_INFO
+ "%s:%d /dev/mem ioremap_change_attr failed %s for %Lx-%Lx\n",
+ current->comm, current->pid,
+ cattr_name(flags),
+ offset, offset + size);
+ return 0;
+ }
+
+ *vma_prot = __pgprot((pgprot_val(*vma_prot) & ~_PAGE_CACHE_MASK) |
+ flags);
+ return 1;
+}
+
+void map_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot)
+{
+ u64 addr = (u64)pfn << PAGE_SHIFT;
+ unsigned long flags;
+ unsigned long want_flags = (pgprot_val(vma_prot) & _PAGE_CACHE_MASK);
+
+ reserve_memtype(addr, addr + size, want_flags, &flags);
+ if (flags != want_flags) {
+ printk(KERN_INFO
+ "%s:%d /dev/mem expected mapping type %s for %Lx-%Lx, got %s\n",
+ current->comm, current->pid,
+ cattr_name(want_flags),
+ addr, addr + size,
+ cattr_name(flags));
+ }
+}
+
+void unmap_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot)
+{
+ u64 addr = (u64)pfn << PAGE_SHIFT;
+
+ free_memtype(addr, addr + size);
+}
+
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 20070b7..e83623e 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -41,36 +41,7 @@
*/
static inline int uncached_access(struct file *file, unsigned long addr)
{
-#if defined(__i386__) && !defined(__arch_um__)
- /*
- * On the PPro and successors, the MTRRs are used to set
- * memory types for physical addresses outside main memory,
- * so blindly setting PCD or PWT on those pages is wrong.
- * For Pentiums and earlier, the surround logic should disable
- * caching for the high addresses through the KEN pin, but
- * we maintain the tradition of paranoia in this code.
- */
- if (file->f_flags & O_SYNC)
- return 1;
- return !( test_bit(X86_FEATURE_MTRR, boot_cpu_data.x86_capability) ||
- test_bit(X86_FEATURE_K6_MTRR, boot_cpu_data.x86_capability) ||
- test_bit(X86_FEATURE_CYRIX_ARR, boot_cpu_data.x86_capability) ||
- test_bit(X86_FEATURE_CENTAUR_MCR, boot_cpu_data.x86_capability) )
- && addr >= __pa(high_memory);
-#elif defined(__x86_64__) && !defined(__arch_um__)
- /*
- * This is broken because it can generate memory type aliases,
- * which can cause cache corruptions
- * But it is only available for root and we have to be bug-to-bug
- * compatible with i386.
- */
- if (file->f_flags & O_SYNC)
- return 1;
- /* same behaviour as i386. PAT always set to cached and MTRRs control the
- caching behaviour.
- Hopefully a full PAT implementation will fix that soon. */
- return 0;
-#elif defined(CONFIG_IA64)
+#if defined(CONFIG_IA64)
/*
* On ia64, we ignore O_SYNC because we cannot tolerate memory attribute aliases.
*/
@@ -108,6 +79,36 @@ static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
}
#endif

+#ifdef CONFIG_NONPROMISC_DEVMEM
+static inline int range_is_allowed(unsigned long pfn, unsigned long size)
+{
+ u64 from = ((u64)pfn) << PAGE_SHIFT;
+ u64 to = from + size;
+ u64 cursor = from;
+
+ while (cursor < to) {
+ if (!devmem_is_allowed(pfn)) {
+ printk(KERN_INFO
+ "Program %s tried to access /dev/mem between %Lx->%Lx.\n",
+ current->comm, from, to);
+ return 0;
+ }
+ cursor += PAGE_SIZE;
+ pfn++;
+ }
+ return 1;
+}
+#else
+static inline int range_is_allowed(unsigned long pfn, unsigned long size)
+{
+ return 1;
+}
+#endif
+
+void __attribute__((weak)) unxlate_dev_mem_ptr(unsigned long phys, void *addr)
+{
+}
+
/*
* This funcion reads the *physical* memory. The f_pos points directly to the
* memory location.
@@ -150,15 +151,25 @@ static ssize_t read_mem(struct file * file, char __user * buf,

sz = min_t(unsigned long, sz, count);

+ if (!range_is_allowed(p >> PAGE_SHIFT, count))
+ return -EPERM;
+
/*
* On ia64 if a page has been mapped somewhere as
* uncached, then it must also be accessed uncached
* by the kernel or data corruption may occur
*/
ptr = xlate_dev_mem_ptr(p);
+ if (!ptr)
+ return -EFAULT;

- if (copy_to_user(buf, ptr, sz))
+ if (copy_to_user(buf, ptr, sz)) {
+ unxlate_dev_mem_ptr(p, ptr);
return -EFAULT;
+ }
+
+ unxlate_dev_mem_ptr(p, ptr);
+
buf += sz;
p += sz;
count -= sz;
@@ -207,20 +218,32 @@ static ssize_t write_mem(struct file * file, const char __user * buf,

sz = min_t(unsigned long, sz, count);

+ if (!range_is_allowed(p >> PAGE_SHIFT, sz))
+ return -EPERM;
+
/*
* On ia64 if a page has been mapped somewhere as
* uncached, then it must also be accessed uncached
* by the kernel or data corruption may occur
*/
ptr = xlate_dev_mem_ptr(p);
+ if (!ptr) {
+ if (written)
+ break;
+ return -EFAULT;
+ }

copied = copy_from_user(ptr, buf, sz);
if (copied) {
written += sz - copied;
+ unxlate_dev_mem_ptr(p, ptr);
if (written)
break;
return -EFAULT;
}
+
+ unxlate_dev_mem_ptr(p, ptr);
+
buf += sz;
p += sz;
count -= sz;
@@ -231,6 +254,12 @@ static ssize_t write_mem(struct file * file, const char __user * buf,
return written;
}

+int __attribute__((weak)) phys_mem_access_prot_allowed(struct file *file,
+ unsigned long pfn, unsigned long size, pgprot_t *vma_prot)
+{
+ return 1;
+}
+
#ifndef __HAVE_PHYS_MEM_ACCESS_PROT
static pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t vma_prot)
@@ -271,6 +300,35 @@ static inline int private_mapping_ok(struct vm_area_struct *vma)
}
#endif

+void __attribute__((weak))
+map_devmem(unsigned long pfn, unsigned long len, pgprot_t prot)
+{
+ /* nothing. architectures can override. */
+}
+
+void __attribute__((weak))
+unmap_devmem(unsigned long pfn, unsigned long len, pgprot_t prot)
+{
+ /* nothing. architectures can override. */
+}
+
+static void mmap_mem_open(struct vm_area_struct *vma)
+{
+ map_devmem(vma->vm_pgoff, vma->vm_end - vma->vm_start,
+ vma->vm_page_prot);
+}
+
+static void mmap_mem_close(struct vm_area_struct *vma)
+{
+ unmap_devmem(vma->vm_pgoff, vma->vm_end - vma->vm_start,
+ vma->vm_page_prot);
+}
+
+static struct vm_operations_struct mmap_mem_ops = {
+ .open = mmap_mem_open,
+ .close = mmap_mem_close
+};
+
static int mmap_mem(struct file * file, struct vm_area_struct * vma)
{
size_t size = vma->vm_end - vma->vm_start;
@@ -281,17 +339,28 @@ static int mmap_mem(struct file * file, struct vm_area_struct * vma)
if (!private_mapping_ok(vma))
return -ENOSYS;

+ if (!range_is_allowed(vma->vm_pgoff, size))
+ return -EPERM;
+
+ if (!phys_mem_access_prot_allowed(file, vma->vm_pgoff, size,
+ &vma->vm_page_prot))
+ return -EINVAL;
+
vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff,
size,
vma->vm_page_prot);

+ vma->vm_ops = &mmap_mem_ops;
+
/* Remap-pfn-range will mark the range VM_IO and VM_RESERVED */
if (remap_pfn_range(vma,
vma->vm_start,
vma->vm_pgoff,
size,
- vma->vm_page_prot))
+ vma->vm_page_prot)) {
+ unmap_devmem(vma->vm_pgoff, size, vma->vm_page_prot);
return -EAGAIN;
+ }
return 0;
}

diff --git a/include/asm-generic/iomap.h b/include/asm-generic/iomap.h
index 67dc84c..76b0cc5 100644
--- a/include/asm-generic/iomap.h
+++ b/include/asm-generic/iomap.h
@@ -60,6 +60,10 @@ extern void iowrite32_rep(void __iomem *port, const void *buf, unsigned long cou
extern void __iomem *ioport_map(unsigned long port, unsigned int nr);
extern void ioport_unmap(void __iomem *);

+#ifndef ARCH_HAS_IOREMAP_WC
+#define ioremap_wc ioremap_nocache
+#endif
+
/* Create a virtual mapping cookie for a PCI BAR (memory or IO) */
struct pci_dev;
extern void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long max);
diff --git a/include/asm-x86/io.h b/include/asm-x86/io.h
index 7b292d3..d5b11f6 100644
--- a/include/asm-x86/io.h
+++ b/include/asm-x86/io.h
@@ -1,3 +1,6 @@
+#ifndef _ASM_X86_IO_H
+#define _ASM_X86_IO_H
+
#define ARCH_HAS_IOREMAP_WC

#ifdef CONFIG_X86_32
@@ -5,7 +8,12 @@
#else
# include "io_64.h"
#endif
+
+extern void *xlate_dev_mem_ptr(unsigned long phys);
+extern void unxlate_dev_mem_ptr(unsigned long phys, void *addr);
+
extern int ioremap_change_attr(unsigned long vaddr, unsigned long size,
unsigned long prot_val);
extern void __iomem *ioremap_wc(unsigned long offset, unsigned long size);

+#endif /* _ASM_X86_IO_H */
diff --git a/include/asm-x86/io_32.h b/include/asm-x86/io_32.h
index 509045f..6e73467 100644
--- a/include/asm-x86/io_32.h
+++ b/include/asm-x86/io_32.h
@@ -49,12 +49,6 @@
#include <linux/vmalloc.h>

/*
- * Convert a physical pointer to a virtual kernel pointer for /dev/mem
- * access
- */
-#define xlate_dev_mem_ptr(p) __va(p)
-
-/*
* Convert a virtual cached pointer to an uncached pointer
*/
#define xlate_dev_kmem_ptr(p) p
diff --git a/include/asm-x86/io_64.h b/include/asm-x86/io_64.h
index c2f5eef..0930bed 100644
--- a/include/asm-x86/io_64.h
+++ b/include/asm-x86/io_64.h
@@ -308,12 +308,6 @@ extern int iommu_bio_merge;
#define BIO_VMERGE_BOUNDARY iommu_bio_merge

/*
- * Convert a physical pointer to a virtual kernel pointer for /dev/mem
- * access
- */
-#define xlate_dev_mem_ptr(p) __va(p)
-
-/*
* Convert a virtual cached pointer to an uncached pointer
*/
#define xlate_dev_kmem_ptr(p) p
diff --git a/include/asm-x86/page.h b/include/asm-x86/page.h
index 6724a4b..b381f4a 100644
--- a/include/asm-x86/page.h
+++ b/include/asm-x86/page.h
@@ -47,6 +47,7 @@
#ifndef __ASSEMBLY__

extern int page_is_ram(unsigned long pagenr);
+extern int devmem_is_allowed(unsigned long pagenr);

extern unsigned long max_pfn_mapped;

diff --git a/include/asm-x86/pgtable.h b/include/asm-x86/pgtable.h
index f1d9f4a..1902f0a 100644
--- a/include/asm-x86/pgtable.h
+++ b/include/asm-x86/pgtable.h
@@ -289,6 +289,15 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)

#define canon_pgprot(p) __pgprot(pgprot_val(p) & __supported_pte_mask)

+#ifndef __ASSEMBLY__
+#define __HAVE_PHYS_MEM_ACCESS_PROT
+struct file;
+pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
+ unsigned long size, pgprot_t vma_prot);
+int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
+ unsigned long size, pgprot_t *vma_prot);
+#endif
+
#ifdef CONFIG_PARAVIRT
#include <asm/paravirt.h>
#else /* !CONFIG_PARAVIRT */