[PATCH 3/3] xen/p2m: Use SetPagePrivate and its friends for M2P overrides.

From: Konrad Rzeszutek Wilk
Date: Sat Sep 24 2011 - 00:57:50 EST


We use the page->private field and hence should use the proper
macros and set proper bits. Also WARN_ON in case somebody
tries to overwrite our data.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
---
arch/x86/xen/p2m.c | 10 ++++++----
1 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index cc2f8dc..6e56b65 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -692,8 +692,9 @@ int m2p_add_override(unsigned long mfn, struct page *page, bool clear_pte)
"m2p_add_override: pfn %lx not mapped", pfn))
return -EINVAL;
}
-
- page->private = mfn;
+ WARN_ON(PagePrivate(page));
+ SetPagePrivate(page);
+ set_page_private(page, mfn);
page->index = pfn_to_mfn(pfn);

if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn))))
@@ -736,7 +737,8 @@ int m2p_remove_override(struct page *page, bool clear_pte)
list_del(&page->lru);
spin_unlock_irqrestore(&m2p_override_lock, flags);
set_phys_to_machine(pfn, page->index);
-
+ WARN_ON(!PagePrivate(page));
+ ClearPagePrivate(page);
if (clear_pte && !PageHighMem(page))
set_pte_at(&init_mm, address, ptep,
pfn_pte(pfn, PAGE_KERNEL));
@@ -758,7 +760,7 @@ struct page *m2p_find_override(unsigned long mfn)
spin_lock_irqsave(&m2p_override_lock, flags);

list_for_each_entry(p, bucket, lru) {
- if (p->private == mfn) {
+ if (page_private(p) == mfn) {
ret = p;
break;
}
--
1.7.4.1

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