[PATCH] include/asm-generic/pgtable.h: Check once and return for pgprot_modify

Chen Gang
2015-12-13T09:11:00Z

pgprot_val() likes an empty operation, and all three checking statements
are related with oldprot, so only check once is enough, the reason is:

- if both "oldprot == pgprot_noncached(oldprot)" and "oldprot ==
pgprot_writecombine(oldprot)" are satisfied.

- So "pgprot_noncached(oldprot) == pgprot_writecombine(oldprot)", too.

- So as the result, it is still equal to check once (for pgprot_device
can get the same result).

Then can return directly.

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
---
include/asm-generic/pgtable.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index 069536a..cd9e7c4 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -306,11 +306,11 @@ static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
{
if (pgprot_val(oldprot) == pgprot_val(pgprot_noncached(oldprot)))
- newprot = pgprot_noncached(newprot);
+ return pgprot_noncached(newprot);
if (pgprot_val(oldprot) == pgprot_val(pgprot_writecombine(oldprot)))
- newprot = pgprot_writecombine(newprot);
+ return pgprot_writecombine(newprot);
if (pgprot_val(oldprot) == pgprot_val(pgprot_device(oldprot)))
- newprot = pgprot_device(newprot);
+ return pgprot_device(newprot);
return newprot;
}
#endif
--
1.9.3