mm/cma: silence warnings due to max() usage

pageblock_order can be (at least) an unsigned int or an unsigned long
depending on the kernel config and architecture, so use max_t(unsigned
long, ...) when comparing it.

fixes these warnings:

In file included from include/asm-generic/bug.h:13:0,
                 from arch/powerpc/include/asm/bug.h:127,
                 from include/linux/bug.h:4,
                 from include/linux/mmdebug.h:4,
                 from include/linux/mm.h:8,
                 from include/linux/memblock.h:18,
                 from mm/cma.c:28:
mm/cma.c: In function 'cma_init_reserved_mem':
include/linux/kernel.h:748:17: warning: comparison of distinct pointer types lacks a cast
  (void) (&_max1 == &_max2);                   ^
mm/cma.c:186:27: note: in expansion of macro 'max'
  alignment = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order);
                           ^
mm/cma.c: In function 'cma_declare_contiguous':
include/linux/kernel.h:748:17: warning: comparison of distinct pointer types lacks a cast
  (void) (&_max1 == &_max2);                   ^
include/linux/kernel.h:747:9: note: in definition of macro 'max'
  typeof(y) _max2 = (y);            ^
mm/cma.c:270:29: note: in expansion of macro 'max'
   (phys_addr_t)PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order));
                             ^
include/linux/kernel.h:748:17: warning: comparison of distinct pointer types lacks a cast
  (void) (&_max1 == &_max2);                   ^
include/linux/kernel.h:747:21: note: in definition of macro 'max'
  typeof(y) _max2 = (y);                        ^
mm/cma.c:270:29: note: in expansion of macro 'max'
   (phys_addr_t)PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order));
                             ^

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20160526150748.5be38a4f@canb.auug.org.au
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/mm/cma.c b/mm/cma.c
index ea506eb18cd6..bd0e1412475e 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -183,7 +183,8 @@ int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
                 return -EINVAL;
 
         /* ensure minimal alignment required by mm core */
-        alignment = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order);
+        alignment = PAGE_SIZE <<
+                        max_t(unsigned long, MAX_ORDER - 1, pageblock_order);
 
         /* alignment should be aligned with order_per_bit */
         if (!IS_ALIGNED(alignment >> PAGE_SHIFT, 1 << order_per_bit))
@@ -266,8 +267,8 @@ int __init cma_declare_contiguous(phys_addr_t base,
          * migratetype page by page allocator's buddy algorithm. In the case,
          * you couldn't get a contiguous memory, which is not what we want.
          */
-        alignment = max(alignment,
-                (phys_addr_t)PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order));
+        alignment = max(alignment,  (phys_addr_t)PAGE_SIZE <<
+                          max_t(unsigned long, MAX_ORDER - 1, pageblock_order));
         base = ALIGN(base, alignment);
         size = ALIGN(size, alignment);
         limit &= ~(alignment - 1);