[PATCH] ppc: make phys_mem_access_prot() work with pfns instead of addresses
Change the phys_mem_access_prot() function to take a pfn instead of an
address. This allows mmap64() to work on /dev/mem for addresses above 4G
on 32-bit architectures. We start with a pfn in mmap_mem(), so there's no
need to convert to an address; in fact, it's actively bad, since the
conversion can overflow when the address is above 4G.
Similarly fix the ppc32 page_is_ram() function to avoid a conversion to an
address by directly comparing to max_pfn. Working with max_pfn instead of
high_memory fixes page_is_ram() to give the right answer for highmem pages.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 695db6a..3ca3317 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -88,13 +88,13 @@
}
EXPORT_SYMBOL(page_is_ram);
-pgprot_t phys_mem_access_prot(struct file *file, unsigned long addr,
+pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t vma_prot)
{
if (ppc_md.phys_mem_access_prot)
- return ppc_md.phys_mem_access_prot(file, addr, size, vma_prot);
+ return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
- if (!page_is_ram(addr >> PAGE_SHIFT))
+ if (!page_is_ram(pfn))
vma_prot = __pgprot(pgprot_val(vma_prot)
| _PAGE_GUARDED | _PAGE_NO_CACHE);
return vma_prot;
diff --git a/arch/ppc/kernel/pci.c b/arch/ppc/kernel/pci.c
index ad4ef2a..e8f4e57 100644
--- a/arch/ppc/kernel/pci.c
+++ b/arch/ppc/kernel/pci.c
@@ -1594,16 +1594,17 @@
* above routine
*/
pgprot_t pci_phys_mem_access_prot(struct file *file,
- unsigned long offset,
+ unsigned long pfn,
unsigned long size,
pgprot_t protection)
{
struct pci_dev *pdev = NULL;
struct resource *found = NULL;
unsigned long prot = pgprot_val(protection);
+ unsigned long offset = pfn << PAGE_SHIFT;
int i;
- if (page_is_ram(offset >> PAGE_SHIFT))
+ if (page_is_ram(pfn))
return prot;
prot |= _PAGE_NO_CACHE | _PAGE_GUARDED;
diff --git a/arch/ppc/mm/init.c b/arch/ppc/mm/init.c
index db94efd..99b48ab 100644
--- a/arch/ppc/mm/init.c
+++ b/arch/ppc/mm/init.c
@@ -637,18 +637,16 @@
*/
int page_is_ram(unsigned long pfn)
{
- unsigned long paddr = (pfn << PAGE_SHIFT);
-
- return paddr < __pa(high_memory);
+ return pfn < max_pfn;
}
-pgprot_t phys_mem_access_prot(struct file *file, unsigned long addr,
+pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t vma_prot)
{
if (ppc_md.phys_mem_access_prot)
- return ppc_md.phys_mem_access_prot(file, addr, size, vma_prot);
+ return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
- if (!page_is_ram(addr >> PAGE_SHIFT))
+ if (!page_is_ram(pfn))
vma_prot = __pgprot(pgprot_val(vma_prot)
| _PAGE_GUARDED | _PAGE_NO_CACHE);
return vma_prot;
diff --git a/arch/ppc64/kernel/pci.c b/arch/ppc64/kernel/pci.c
index b2fb674..3d2106b 100644
--- a/arch/ppc64/kernel/pci.c
+++ b/arch/ppc64/kernel/pci.c
@@ -726,16 +726,17 @@
* above routine
*/
pgprot_t pci_phys_mem_access_prot(struct file *file,
- unsigned long offset,
+ unsigned long pfn,
unsigned long size,
pgprot_t protection)
{
struct pci_dev *pdev = NULL;
struct resource *found = NULL;
unsigned long prot = pgprot_val(protection);
+ unsigned long offset = pfn << PAGE_SHIFT;
int i;
- if (page_is_ram(offset >> PAGE_SHIFT))
+ if (page_is_ram(pfn))
return __pgprot(prot);
prot |= _PAGE_NO_CACHE | _PAGE_GUARDED;
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index f182752..9df928d 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -231,9 +231,7 @@
static int mmap_mem(struct file * file, struct vm_area_struct * vma)
{
#if defined(__HAVE_PHYS_MEM_ACCESS_PROT)
- unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
-
- vma->vm_page_prot = phys_mem_access_prot(file, offset,
+ vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff,
vma->vm_end - vma->vm_start,
vma->vm_page_prot);
#elif defined(pgprot_noncached)
diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
index 70be700..ca02aa2 100644
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c
@@ -918,7 +918,7 @@
}
#endif
#elif defined(__powerpc__)
- vma->vm_page_prot = phys_mem_access_prot(file, off,
+ vma->vm_page_prot = phys_mem_access_prot(file, off >> PAGE_SHIFT,
vma->vm_end - vma->vm_start,
vma->vm_page_prot);
#elif defined(__alpha__)
diff --git a/include/asm-powerpc/machdep.h b/include/asm-powerpc/machdep.h
index 706508b..451b345 100644
--- a/include/asm-powerpc/machdep.h
+++ b/include/asm-powerpc/machdep.h
@@ -144,7 +144,7 @@
/* Get access protection for /dev/mem */
pgprot_t (*phys_mem_access_prot)(struct file *file,
- unsigned long offset,
+ unsigned long pfn,
unsigned long size,
pgprot_t vma_prot);
diff --git a/include/asm-ppc/machdep.h b/include/asm-ppc/machdep.h
index 6c6d23ab..f01255b 100644
--- a/include/asm-ppc/machdep.h
+++ b/include/asm-ppc/machdep.h
@@ -98,7 +98,7 @@
/* Get access protection for /dev/mem */
pgprot_t (*phys_mem_access_prot)(struct file *file,
- unsigned long offset,
+ unsigned long pfn,
unsigned long size,
pgprot_t vma_prot);
diff --git a/include/asm-ppc/pci.h b/include/asm-ppc/pci.h
index 643740d..61434ed 100644
--- a/include/asm-ppc/pci.h
+++ b/include/asm-ppc/pci.h
@@ -126,7 +126,7 @@
struct file;
extern pgprot_t pci_phys_mem_access_prot(struct file *file,
- unsigned long offset,
+ unsigned long pfn,
unsigned long size,
pgprot_t prot);
diff --git a/include/asm-ppc/pgtable.h b/include/asm-ppc/pgtable.h
index eee601b..b28a713 100644
--- a/include/asm-ppc/pgtable.h
+++ b/include/asm-ppc/pgtable.h
@@ -705,7 +705,7 @@
#define pgprot_noncached(prot) (__pgprot(pgprot_val(prot) | _PAGE_NO_CACHE | _PAGE_GUARDED))
struct file;
-extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long addr,
+extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t vma_prot);
#define __HAVE_PHYS_MEM_ACCESS_PROT
diff --git a/include/asm-ppc64/pci.h b/include/asm-ppc64/pci.h
index a88bbfc..342e2d7 100644
--- a/include/asm-ppc64/pci.h
+++ b/include/asm-ppc64/pci.h
@@ -168,7 +168,7 @@
struct file;
extern pgprot_t pci_phys_mem_access_prot(struct file *file,
- unsigned long offset,
+ unsigned long pfn,
unsigned long size,
pgprot_t prot);
diff --git a/include/asm-ppc64/pgtable.h b/include/asm-ppc64/pgtable.h
index c83679c..8cf5991 100644
--- a/include/asm-ppc64/pgtable.h
+++ b/include/asm-ppc64/pgtable.h
@@ -471,7 +471,7 @@
#define pgprot_noncached(prot) (__pgprot(pgprot_val(prot) | _PAGE_NO_CACHE | _PAGE_GUARDED))
struct file;
-extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long addr,
+extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t vma_prot);
#define __HAVE_PHYS_MEM_ACCESS_PROT