[PATCH] EFI, /dev/mem: simplify efi_mem_attribute_range()

Pass the size, not a pointer to the size, to efi_mem_attribute_range().

This function validates memory regions for the /dev/mem read/write/mmap paths.
The pointer allows arches to reduce the size of the range, but I think that's
unnecessary complexity.  Simplifying it will let me use
efi_mem_attribute_range() to improve the ia64 ioremap() implementation.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Matt Domsch <Matt_Domsch@dell.com>
Cc: "Tolentino, Matthew E" <matthew.e.tolentino@intel.com>
Cc: "Brown, Len" <len.brown@intel.com>
Cc: Andi Kleen <ak@muc.de>
Acked-by: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 20 insertions, 21 deletions

diff --git a/arch/ia64/kernel/efi.c b/arch/ia64/kernel/efi.c
index 9990320b6f9a..2993748c13df 100644
--- a/arch/ia64/kernel/efi.c
+++ b/arch/ia64/kernel/efi.c
@@ -677,27 +677,34 @@ EXPORT_SYMBOL(efi_mem_attributes);
 /*
  * Determines whether the memory at phys_addr supports the desired
  * attribute (WB, UC, etc).  If this returns 1, the caller can safely
- * access *size bytes at phys_addr with the specified attribute.
+ * access size bytes at phys_addr with the specified attribute.
  */
-static int
-efi_mem_attribute_range (unsigned long phys_addr, unsigned long *size, u64 attr)
+int
+efi_mem_attribute_range (unsigned long phys_addr, unsigned long size, u64 attr)
 {
+        unsigned long end = phys_addr + size;
         efi_memory_desc_t *md = efi_memory_descriptor(phys_addr);
-        unsigned long md_end;
 
-        if (!md || (md->attribute & attr) != attr)
+        /*
+         * Some firmware doesn't report MMIO regions in the EFI memory
+         * map.  The Intel BigSur (a.k.a. HP i2000) has this problem.
+         * On those platforms, we have to assume UC is valid everywhere.
+         */
+        if (!md || (md->attribute & attr) != attr) {
+                if (attr == EFI_MEMORY_UC && !efi_memmap_has_mmio())
+                        return 1;
                 return 0;
+        }
 
         do {
-                md_end = efi_md_end(md);
-                if (phys_addr + *size <= md_end)
+                unsigned long md_end = efi_md_end(md);
+
+                if (end <= md_end)
                         return 1;
 
                 md = efi_memory_descriptor(md_end);
-                if (!md || (md->attribute & attr) != attr) {
-                        *size = md_end - phys_addr;
-                        return 1;
-                }
+                if (!md || (md->attribute & attr) != attr)
+                        return 0;
         } while (md);
         return 0;
 }
@@ -708,7 +715,7 @@ efi_mem_attribute_range (unsigned long phys_addr, unsigned long *size, u64 attr)
  * control access size.
  */
 int
-valid_phys_addr_range (unsigned long phys_addr, unsigned long *size)
+valid_phys_addr_range (unsigned long phys_addr, unsigned long size)
 {
         return efi_mem_attribute_range(phys_addr, size, EFI_MEMORY_WB);
 }
@@ -723,7 +730,7 @@ valid_phys_addr_range (unsigned long phys_addr, unsigned long *size)
  * because that doesn't appear in the boot-time EFI memory map.
  */
 int
-valid_mmap_phys_addr_range (unsigned long phys_addr, unsigned long *size)
+valid_mmap_phys_addr_range (unsigned long phys_addr, unsigned long size)
 {
         if (efi_mem_attribute_range(phys_addr, size, EFI_MEMORY_WB))
                 return 1;
@@ -731,14 +738,6 @@ valid_mmap_phys_addr_range (unsigned long phys_addr, unsigned long *size)
         if (efi_mem_attribute_range(phys_addr, size, EFI_MEMORY_UC))
                 return 1;
 
-        /*
-         * Some firmware doesn't report MMIO regions in the EFI memory map.
-         * The Intel BigSur (a.k.a. HP i2000) has this problem.  In this
-         * case, we can't use the EFI memory map to validate mmap requests.
-         */
-        if (!efi_memmap_has_mmio())
-                return 1;
-
         return 0;
 }