---

yaml
---
r: 267079
b: refs/heads/master
c: 85055dd
h: refs/heads/master
i:
  267077: e10c5de
  267075: 85bcac4
  267071: bc4d8db
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: ca123102f69fb260221502ade9bbc069290fae84
+refs/heads/master: 85055dd805f0822f13f736bee2a521e222c38293

trunk/arch/s390/Kconfig

@@ -91,6 +91,7 @@ config S390
 	select HAVE_ARCH_MUTEX_CPU_RELAX
 	select HAVE_ARCH_JUMP_LABEL if !MARCH_G5
 	select HAVE_RCU_TABLE_FREE if SMP
+	select ARCH_SAVE_PAGE_KEYS if HIBERNATION
 	select ARCH_INLINE_SPIN_TRYLOCK
 	select ARCH_INLINE_SPIN_TRYLOCK_BH
 	select ARCH_INLINE_SPIN_LOCK

trunk/arch/s390/kernel/suspend.c

@@ -7,13 +7,131 @@
  */
 
 #include <linux/pfn.h>
+#include <linux/mm.h>
 #include <asm/system.h>
 
 /*
  * References to section boundaries
  */
 extern const void __nosave_begin, __nosave_end;
 
+/*
+ * The restore of the saved pages in an hibernation image will set
+ * the change and referenced bits in the storage key for each page.
+ * Overindication of the referenced bits after an hibernation cycle
+ * does not cause any harm but the overindication of the change bits
+ * would cause trouble.
+ * Use the ARCH_SAVE_PAGE_KEYS hooks to save the storage key of each
+ * page to the most significant byte of the associated page frame
+ * number in the hibernation image.
+ */
+
+/*
+ * Key storage is allocated as a linked list of pages.
+ * The size of the keys array is (PAGE_SIZE - sizeof(long))
+ */
+struct page_key_data {
+	struct page_key_data *next;
+	unsigned char data[];
+};
+
+#define PAGE_KEY_DATA_SIZE	(PAGE_SIZE - sizeof(struct page_key_data *))
+
+static struct page_key_data *page_key_data;
+static struct page_key_data *page_key_rp, *page_key_wp;
+static unsigned long page_key_rx, page_key_wx;
+
+/*
+ * For each page in the hibernation image one additional byte is
+ * stored in the most significant byte of the page frame number.
+ * On suspend no additional memory is required but on resume the
+ * keys need to be memorized until the page data has been restored.
+ * Only then can the storage keys be set to their old state.
+ */
+unsigned long page_key_additional_pages(unsigned long pages)
+{
+	return DIV_ROUND_UP(pages, PAGE_KEY_DATA_SIZE);
+}
+
+/*
+ * Free page_key_data list of arrays.
+ */
+void page_key_free(void)
+{
+	struct page_key_data *pkd;
+
+	while (page_key_data) {
+		pkd = page_key_data;
+		page_key_data = pkd->next;
+		free_page((unsigned long) pkd);
+	}
+}
+
+/*
+ * Allocate page_key_data list of arrays with enough room to store
+ * one byte for each page in the hibernation image.
+ */
+int page_key_alloc(unsigned long pages)
+{
+	struct page_key_data *pk;
+	unsigned long size;
+
+	size = DIV_ROUND_UP(pages, PAGE_KEY_DATA_SIZE);
+	while (size--) {
+		pk = (struct page_key_data *) get_zeroed_page(GFP_KERNEL);
+		if (!pk) {
+			page_key_free();
+			return -ENOMEM;
+		}
+		pk->next = page_key_data;
+		page_key_data = pk;
+	}
+	page_key_rp = page_key_wp = page_key_data;
+	page_key_rx = page_key_wx = 0;
+	return 0;
+}
+
+/*
+ * Save the storage key into the upper 8 bits of the page frame number.
+ */
+void page_key_read(unsigned long *pfn)
+{
+	unsigned long addr;
+
+	addr = (unsigned long) page_address(pfn_to_page(*pfn));
+	*(unsigned char *) pfn = (unsigned char) page_get_storage_key(addr);
+}
+
+/*
+ * Extract the storage key from the upper 8 bits of the page frame number
+ * and store it in the page_key_data list of arrays.
+ */
+void page_key_memorize(unsigned long *pfn)
+{
+	page_key_wp->data[page_key_wx] = *(unsigned char *) pfn;
+	*(unsigned char *) pfn = 0;
+	if (++page_key_wx < PAGE_KEY_DATA_SIZE)
+		return;
+	page_key_wp = page_key_wp->next;
+	page_key_wx = 0;
+}
+
+/*
+ * Get the next key from the page_key_data list of arrays and set the
+ * storage key of the page referred by @address. If @address refers to
+ * a "safe" page the swsusp_arch_resume code will transfer the storage
+ * key from the buffer page to the original page.
+ */
+void page_key_write(void *address)
+{
+	page_set_storage_key((unsigned long) address,
+			     page_key_rp->data[page_key_rx], 0);
+	if (++page_key_rx >= PAGE_KEY_DATA_SIZE)
+		return;
+	page_key_rp = page_key_rp->next;
+	page_key_rx = 0;
+}
+
 int pfn_is_nosave(unsigned long pfn)
 {
 	unsigned long nosave_begin_pfn = PFN_DOWN(__pa(&__nosave_begin));

trunk/arch/s390/kernel/swsusp_asm64.S

@@ -136,11 +136,14 @@ ENTRY(swsusp_arch_resume)
 0:
 	lg	%r2,8(%r1)
 	lg	%r4,0(%r1)
+	iske	%r0,%r4
 	lghi	%r3,PAGE_SIZE
 	lghi	%r5,PAGE_SIZE
 1:
 	mvcle	%r2,%r4,0
 	jo	1b
+	lg	%r2,8(%r1)
+	sske	%r0,%r2
 	lg	%r1,16(%r1)
 	ltgr	%r1,%r1
 	jnz	0b

trunk/include/linux/suspend.h

@@ -386,4 +386,38 @@ static inline void unlock_system_sleep(void)
 }
 #endif
 
+#ifdef CONFIG_ARCH_SAVE_PAGE_KEYS
+/*
+ * The ARCH_SAVE_PAGE_KEYS functions can be used by an architecture
+ * to save/restore additional information to/from the array of page
+ * frame numbers in the hibernation image. For s390 this is used to
+ * save and restore the storage key for each page that is included
+ * in the hibernation image.
+ */
+unsigned long page_key_additional_pages(unsigned long pages);
+int page_key_alloc(unsigned long pages);
+void page_key_free(void);
+void page_key_read(unsigned long *pfn);
+void page_key_memorize(unsigned long *pfn);
+void page_key_write(void *address);
+
+#else /* !CONFIG_ARCH_SAVE_PAGE_KEYS */
+
+static inline unsigned long page_key_additional_pages(unsigned long pages)
+{
+	return 0;
+}
+
+static inline int  page_key_alloc(unsigned long pages)
+{
+	return 0;
+}
+
+static inline void page_key_free(void) {}
+static inline void page_key_read(unsigned long *pfn) {}
+static inline void page_key_memorize(unsigned long *pfn) {}
+static inline void page_key_write(void *address) {}
+
+#endif /* !CONFIG_ARCH_SAVE_PAGE_KEYS */
+
 #endif /* _LINUX_SUSPEND_H */

trunk/kernel/power/Kconfig

@@ -65,6 +65,9 @@ config HIBERNATION
 
 	  For more information take a look at <file:Documentation/power/swsusp.txt>.
 
+config ARCH_SAVE_PAGE_KEYS
+	bool
+
 config PM_STD_PARTITION
 	string "Default resume partition"
 	depends on HIBERNATION

trunk/kernel/power/snapshot.c

@@ -1339,6 +1339,9 @@ int hibernate_preallocate_memory(void)
 	count += highmem;
 	count -= totalreserve_pages;
 
+	/* Add number of pages required for page keys (s390 only). */
+	size += page_key_additional_pages(saveable);
+
 	/* Compute the maximum number of saveable pages to leave in memory. */
 	max_size = (count - (size + PAGES_FOR_IO)) / 2
 			- 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE);
@@ -1662,6 +1665,8 @@ pack_pfns(unsigned long *buf, struct memory_bitmap *bm)
 		buf[j] = memory_bm_next_pfn(bm);
 		if (unlikely(buf[j] == BM_END_OF_MAP))
 			break;
+		/* Save page key for data page (s390 only). */
+		page_key_read(buf + j);
 	}
 }
 
@@ -1821,6 +1826,9 @@ static int unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm)
 		if (unlikely(buf[j] == BM_END_OF_MAP))
 			break;
 
+		/* Extract and buffer page key for data page (s390 only). */
+		page_key_memorize(buf + j);
+
 		if (memory_bm_pfn_present(bm, buf[j]))
 			memory_bm_set_bit(bm, buf[j]);
 		else
@@ -2223,6 +2231,11 @@ int snapshot_write_next(struct snapshot_handle *handle)
 		if (error)
 			return error;
 
+		/* Allocate buffer for page keys. */
+		error = page_key_alloc(nr_copy_pages);
+		if (error)
+			return error;
+
 	} else if (handle->cur <= nr_meta_pages + 1) {
 		error = unpack_orig_pfns(buffer, &copy_bm);
 		if (error)
@@ -2243,6 +2256,8 @@ int snapshot_write_next(struct snapshot_handle *handle)
 		}
 	} else {
 		copy_last_highmem_page();
+		/* Restore page key for data page (s390 only). */
+		page_key_write(handle->buffer);
 		handle->buffer = get_buffer(&orig_bm, &ca);
 		if (IS_ERR(handle->buffer))
 			return PTR_ERR(handle->buffer);
@@ -2264,6 +2279,9 @@ int snapshot_write_next(struct snapshot_handle *handle)
 void snapshot_write_finalize(struct snapshot_handle *handle)
 {
 	copy_last_highmem_page();
+	/* Restore page key for data page (s390 only). */
+	page_key_write(handle->buffer);
+	page_key_free();
 	/* Free only if we have loaded the image entirely */
 	if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages) {
 		memory_bm_free(&orig_bm, PG_UNSAFE_CLEAR);