ARC: mm: PAE40: Fix crash at munmap

commit 1c3c90930392 broke PAE40. Macro pfn_pte(pfn, prot) creates paddr
from pfn, but the page shift was getting truncated to 32 bits since we lost
the proper cast to 64 bits (for PAE400

Instead of reverting that commit, use a better helper which is 32/64 bits
safe just like ARM implementation.

Fixes: 1c3c90930392 ("ARC: mm: fix build breakage with STRICT_MM_TYPECHECKS")
Cc: <stable@vger.kernel.org>   #4.4+
Signed-off-by: Yuriy Kolerov <yuriy.kolerov@synopsys.com>
[vgupta: massaged changelog]
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

diff --git a/arch/arc/include/asm/pgtable.h b/arch/arc/include/asm/pgtable.h
index 89eeb37..e94ca72 100644 (file)
--- a/arch/arc/include/asm/pgtable.h
+++ b/arch/arc/include/asm/pgtable.h
@@ -280,7 +280,7 @@ static inline void pmd_set(pmd_t *pmdp, pte_t *ptep)
 
 #define pte_page(pte)          pfn_to_page(pte_pfn(pte))
 #define mk_pte(page, prot)     pfn_pte(page_to_pfn(page), prot)
-#define pfn_pte(pfn, prot)     __pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
+#define pfn_pte(pfn, prot)     __pte(__pfn_to_phys(pfn) | pgprot_val(prot))
 
 /* Don't use virt_to_pfn for macros below: could cause truncations for PAE40*/
 #define pte_pfn(pte)           (pte_val(pte) >> PAGE_SHIFT)