[tip:x86/mm] x86/mm/cpa: Cleanup split_large_page() and its callee

From: tip-bot for Borislav Petkov
Date: Wed Apr 10 2013 - 09:52:04 EST

Commit-ID: 5952886bfeec065041d04dfcc2693b581e8f2424
Gitweb: http://git.kernel.org/tip/5952886bfeec065041d04dfcc2693b581e8f2424
Author: Borislav Petkov <bp@xxxxxxx>
AuthorDate: Thu, 21 Mar 2013 18:16:57 +0100
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 10 Apr 2013 14:39:08 +0200

x86/mm/cpa: Cleanup split_large_page() and its callee

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>
Acked-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1363886217-24703-1-git-send-email-bp@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
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 567b5d0..e642300 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 091934e..25b1d35 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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