summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorRafael J. Wysocki <rjw@sisk.pl>2008-02-20 01:47:44 +0100
committerLen Brown <len.brown@intel.com>2008-02-21 02:15:28 -0500
commit8a235efad548abd2ab5ebea45a9ffa750c814375 (patch)
tree9b8c6c1fa3d2e28d9bb198d7019cba8883d5299e
parente80af3a8dbbbf431b2070cc760699f01c5a6ac69 (diff)
Hibernation: Handle DEBUG_PAGEALLOC on x86
Make hibernation work with CONFIG_DEBUG_PAGEALLOC set on x86, by checking if the pages to be copied are marked as present in the kernel mapping and temporarily marking them as present if that's not the case. No functional modifications are introduced if CONFIG_DEBUG_PAGEALLOC is unset. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Len Brown <len.brown@intel.com>
-rw-r--r--arch/x86/mm/pageattr.c19
-rw-r--r--include/linux/mm.h6
-rw-r--r--kernel/power/snapshot.c42
3 files changed, 53 insertions, 14 deletions
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index e2a74ea11a53..464d8fc21ce6 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -899,7 +899,24 @@ void kernel_map_pages(struct page *page, int numpages, int enable)
*/
cpa_fill_pool();
}
-#endif
+
+#ifdef CONFIG_HIBERNATION
+
+bool kernel_page_present(struct page *page)
+{
+ unsigned int level;
+ pte_t *pte;
+
+ if (PageHighMem(page))
+ return false;
+
+ pte = lookup_address((unsigned long)page_address(page), &level);
+ return (pte_val(*pte) & _PAGE_PRESENT);
+}
+
+#endif /* CONFIG_HIBERNATION */
+
+#endif /* CONFIG_DEBUG_PAGEALLOC */
/*
* The testcases use internal knowledge of the implementation that shouldn't
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 26c7124b841a..3b3e1341163f 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1171,12 +1171,18 @@ static inline void enable_debug_pagealloc(void)
{
debug_pagealloc_enabled = 1;
}
+#ifdef CONFIG_HIBERNATION
+extern bool kernel_page_present(struct page *page);
+#endif /* CONFIG_HIBERNATION */
#else
static inline void
kernel_map_pages(struct page *page, int numpages, int enable) {}
static inline void enable_debug_pagealloc(void)
{
}
+#ifdef CONFIG_HIBERNATION
+static inline bool kernel_page_present(struct page *page) { return true; }
+#endif /* CONFIG_HIBERNATION */
#endif
extern struct vm_area_struct *get_gate_vma(struct task_struct *tsk);
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 95250d7c8d91..72a020cabb4c 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -875,8 +875,8 @@ static inline void *saveable_highmem_page(unsigned long pfn) { return NULL; }
#endif /* CONFIG_HIGHMEM */
/**
- * saveable - Determine whether a non-highmem page should be included in
- * the suspend image.
+ * saveable_page - Determine whether a non-highmem page should be included
+ * in the suspend image.
*
* We should save the page if it isn't Nosave, and is not in the range
* of pages statically defined as 'unsaveable', and it isn't a part of
@@ -897,7 +897,8 @@ static struct page *saveable_page(unsigned long pfn)
if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
return NULL;
- if (PageReserved(page) && pfn_is_nosave(pfn))
+ if (PageReserved(page)
+ && (!kernel_page_present(page) || pfn_is_nosave(pfn)))
return NULL;
return page;
@@ -938,6 +939,25 @@ static inline void do_copy_page(long *dst, long *src)
*dst++ = *src++;
}
+
+/**
+ * safe_copy_page - check if the page we are going to copy is marked as
+ * present in the kernel page tables (this always is the case if
+ * CONFIG_DEBUG_PAGEALLOC is not set and in that case
+ * kernel_page_present() always returns 'true').
+ */
+static void safe_copy_page(void *dst, struct page *s_page)
+{
+ if (kernel_page_present(s_page)) {
+ do_copy_page(dst, page_address(s_page));
+ } else {
+ kernel_map_pages(s_page, 1, 1);
+ do_copy_page(dst, page_address(s_page));
+ kernel_map_pages(s_page, 1, 0);
+ }
+}
+
+
#ifdef CONFIG_HIGHMEM
static inline struct page *
page_is_saveable(struct zone *zone, unsigned long pfn)
@@ -946,8 +966,7 @@ page_is_saveable(struct zone *zone, unsigned long pfn)
saveable_highmem_page(pfn) : saveable_page(pfn);
}
-static inline void
-copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
+static void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
{
struct page *s_page, *d_page;
void *src, *dst;
@@ -961,29 +980,26 @@ copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
kunmap_atomic(src, KM_USER0);
kunmap_atomic(dst, KM_USER1);
} else {
- src = page_address(s_page);
if (PageHighMem(d_page)) {
/* Page pointed to by src may contain some kernel
* data modified by kmap_atomic()
*/
- do_copy_page(buffer, src);
+ safe_copy_page(buffer, s_page);
dst = kmap_atomic(pfn_to_page(dst_pfn), KM_USER0);
memcpy(dst, buffer, PAGE_SIZE);
kunmap_atomic(dst, KM_USER0);
} else {
- dst = page_address(d_page);
- do_copy_page(dst, src);
+ safe_copy_page(page_address(d_page), s_page);
}
}
}
#else
#define page_is_saveable(zone, pfn) saveable_page(pfn)
-static inline void
-copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
+static inline void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
{
- do_copy_page(page_address(pfn_to_page(dst_pfn)),
- page_address(pfn_to_page(src_pfn)));
+ safe_copy_page(page_address(pfn_to_page(dst_pfn)),
+ pfn_to_page(src_pfn));
}
#endif /* CONFIG_HIGHMEM */