[PATCH] ppc: make phys_mem_access_prot() work with pfns instead of addresses
Roland Dreier [Sat, 29 Oct 2005 00:46:18 +0000 (17:46 -0700)]
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>

12 files changed:
arch/powerpc/mm/mem.c
arch/ppc/kernel/pci.c
arch/ppc/mm/init.c
arch/ppc64/kernel/pci.c
drivers/char/mem.c
drivers/video/fbmem.c
include/asm-powerpc/machdep.h
include/asm-ppc/machdep.h
include/asm-ppc/pci.h
include/asm-ppc/pgtable.h
include/asm-ppc64/pci.h
include/asm-ppc64/pgtable.h

index 695db6a..3ca3317 100644 (file)
@@ -88,13 +88,13 @@ int page_is_ram(unsigned long pfn)
 }
 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;
index ad4ef2a..e8f4e57 100644 (file)
@@ -1594,16 +1594,17 @@ static pgprot_t __pci_mmap_set_pgprot(struct pci_dev *dev, struct resource *rp,
  * 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;
index db94efd..99b48ab 100644 (file)
@@ -637,18 +637,16 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
  */
 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;
index b2fb674..3d2106b 100644 (file)
@@ -726,16 +726,17 @@ static pgprot_t __pci_mmap_set_pgprot(struct pci_dev *dev, struct resource *rp,
  * 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;
index f182752..9df928d 100644 (file)
@@ -231,9 +231,7 @@ static ssize_t write_mem(struct file * file, const char __user * buf,
 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)
index 70be700..ca02aa2 100644 (file)
@@ -918,7 +918,7 @@ fb_mmap(struct file *file, struct vm_area_struct * vma)
        }
 #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__)
index 706508b..451b345 100644 (file)
@@ -144,7 +144,7 @@ struct machdep_calls {
        
        /* 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);
 
index 6c6d23a..f01255b 100644 (file)
@@ -98,7 +98,7 @@ struct machdep_calls {
 
        /* 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);
 
index 643740d..61434ed 100644 (file)
@@ -126,7 +126,7 @@ extern void pcibios_add_platform_entries(struct pci_dev *dev);
 
 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);
 
index eee601b..b28a713 100644 (file)
@@ -705,7 +705,7 @@ static inline void __ptep_set_access_flags(pte_t *ptep, pte_t entry, int dirty)
 #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
 
index a88bbfc..342e2d7 100644 (file)
@@ -168,7 +168,7 @@ extern void pcibios_add_platform_entries(struct pci_dev *dev);
 
 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);
 
index c83679c..8cf5991 100644 (file)
@@ -471,7 +471,7 @@ static inline void __ptep_set_access_flags(pte_t *ptep, pte_t entry, int dirty)
 #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