[PATCH 3.18 56/68] mm/cma: silence warnings due to max() usage

Greg Kroah-Hartman
2017-05-05T18:34:02Z

From: Stephen Rothwell <sfr@canb.auug.org.au>

commit badbda53e505089062e194c614e6f23450bc98b2 upstream.

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>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
mm/cma.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

--- a/mm/cma.c
+++ b/mm/cma.c
@@ -168,7 +168,8 @@ int __init cma_init_reserved_mem(phys_ad
return -EINVAL;

/* ensure minimal alignment requied 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))
@@ -250,8 +251,8 @@ int __init cma_declare_contiguous(phys_a
* 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);