x86/mm: Clean up types in xlate_dev_mem_ptr()

Ingo Molnar · Ingo Molnar · commit 94d4b4765b7d · 2015-04-20T08:41:37.000+02:00
Pavel Machek reported the following compiler warning on x86/32 CONFIG_HIGHMEM64G=y builds: arch/x86/mm/ioremap.c:344:10: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] Clean up the types in this function by using a single natural type for internal calculations (unsigned long), to make it more apparent what's happening, and also to remove fragile casts. Reported-by: Pavel Machek <pavel@ucw.cz> Cc: jgross@suse.com Cc: roland@purestorage.com Link: http://lkml.kernel.org/r/20150416080440.GA507@amd Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
@@ -332,18 +332,20 @@ EXPORT_SYMBOL(iounmap);
  */
 void *xlate_dev_mem_ptr(phys_addr_t phys)
 {
-	void *addr;
-	unsigned long start = phys & PAGE_MASK;
+	unsigned long start  = phys &  PAGE_MASK;
+	unsigned long offset = phys & ~PAGE_MASK;
+	unsigned long vaddr;
 
 	/* If page is RAM, we can use __va. Otherwise ioremap and unmap. */
 	if (page_is_ram(start >> PAGE_SHIFT))
 		return __va(phys);
 
-	addr = (void __force *)ioremap_cache(start, PAGE_SIZE);
-	if (addr)
-		addr = (void *)((unsigned long)addr | (phys & ~PAGE_MASK));
+	vaddr = (unsigned long)ioremap_cache(start, PAGE_SIZE);
+	/* Only add the offset on success and return NULL if the ioremap() failed: */
+	if (vaddr)
+		vaddr += offset;
 
-	return addr;
+	return (void *)vaddr;
 }
 
 void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr)
