[PATCH] x86, cpa: Cleanup split_large_page and its callee

From: Borislav Petkov
Date: Thu Mar 21 2013 - 13:17:14 EST

From: Borislav Petkov <bp@xxxxxxx>

So basically we're generating the pte_t * from a struct page and we're
handing it down to the __split_large_page internal version which then
goes and gets back struct page * from it because it needs it.

Change the caller to hand down struct page * directly and the callee can
compute the pte_t itself.

Net save is one virt_to_page() call and simpler code. While at it, make
__split_large_page static.

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
arch/x86/include/asm/pgtable_types.h | 1 -
arch/x86/mm/pageattr.c | 9 ++++-----
2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index 567b5d0632b2..e6423002c10b 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -351,7 +351,6 @@ static inline void update_page_count(int level, unsigned long pages) { }
* as a pte too.
extern pte_t *lookup_address(unsigned long address, unsigned int *level);
-extern int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase);
extern phys_addr_t slow_virt_to_phys(void *__address);

#endif /* !__ASSEMBLY__ */
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 091934e1d0d9..25b1d35c76cb 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -542,13 +542,14 @@ out_unlock:
return do_split;

-int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase)
+static int
+__split_large_page(pte_t *kpte, unsigned long address, struct page *base)
+ pte_t *pbase = (pte_t *)page_address(base);
unsigned long pfn, pfninc = 1;
unsigned int i, level;
pte_t *tmp;
pgprot_t ref_prot;
- struct page *base = virt_to_page(pbase);

@@ -633,7 +634,6 @@ int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase)

static int split_large_page(pte_t *kpte, unsigned long address)
- pte_t *pbase;
struct page *base;

if (!debug_pagealloc)
@@ -644,8 +644,7 @@ static int split_large_page(pte_t *kpte, unsigned long address)
if (!base)
return -ENOMEM;

- pbase = (pte_t *)page_address(base);
- if (__split_large_page(kpte, address, pbase))
+ if (__split_large_page(kpte, address, base))

return 0;

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