*/
#include <linux/pfn.h>
+#include <linux/mm.h>
#include <asm/system.h>
/*
*/
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));
}
#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 */
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);
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);
}
}
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
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, ©_bm);
if (error)
}
} 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);
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);
projects / users / hch / configfs.git / commitdiff