As noted by David:
pte_page() is a macro defined as follows;
include/asm-sh/pgtable.h
#define pte_page(x) phys_to_page(pte_val(x)&PTE_PHYS_MASK)
include/asm-sh/page.h
#define phys_to_page(phys) (pfn_to_page(phys >> PAGE_SHIFT))
So as you can see the phys_to_page() macro doesn't wrap the 'phys'
parameter in parentheses so we end up with;
pte_val(x)&PTE_PHYS_MASK >> PAGE_SHIFT
Which is not what we wanted as '>>' has a higher precedence than bitwise
AND. I dug into the git repository and I believe this bug was added with
this commit (
104b8deaa5c0144cccfc7d914413ff80c7176af1);
2006-03-27 KAMEZAWA Hiroyuki [PATCH] unify pfn_to_page: sh pfn_to_page
-#define phys_to_page(phys) (mem_map + (((phys)-__MEMORY_START) >>
PAGE_SHIFT))
-#define page_to_phys(page) (((page - mem_map) << PAGE_SHIFT) +
__MEMORY_START)
+#define phys_to_page(phys) (pfn_to_page(phys >> PAGE_SHIFT))
+#define page_to_phys(page) (page_to_pfn(page) << PAGE_SHIFT)
Reported-by: David ADDISON <david.addison@st.com>
Reported-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
#define __va(x) ((void *)((unsigned long)(x)+PAGE_OFFSET))
#define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
-#define phys_to_page(phys) (pfn_to_page(phys >> PAGE_SHIFT))
#define page_to_phys(page) (page_to_pfn(page) << PAGE_SHIFT)
/* PFN start number, because of __MEMORY_START */
#define pmd_bad(x) (pmd_val(x) & ~PAGE_MASK)
#define pages_to_mb(x) ((x) >> (20-PAGE_SHIFT))
-#define pte_page(x) phys_to_page(pte_val(x)&PTE_PHYS_MASK)
+#define pte_page(x) pfn_to_page(pte_pfn(x))
/*
* The following only work if pte_present() is true.