@@ -31,6 +31,7 @@
#include <asm/kexec.h>
#include <asm/memory.h>
#include <asm/mmu_context.h>
+#include <asm/mte.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/pgtable-hwdef.h>
@@ -277,6 +278,115 @@ static int create_safe_exec_page(void *src_start, size_t length,
#define dcache_clean_range(start, end) __flush_dcache_area(start, (end - start))
+#ifdef CONFIG_ARM64_MTE
+
+static DEFINE_XARRAY(mte_pages);
+
+static int save_tags(struct page *page, unsigned long pfn)
+{
+ void *tag_storage, *ret;
+
+ tag_storage = mte_allocate_tag_storage();
+ if (!tag_storage)
+ return -ENOMEM;
+
+ mte_save_page_tags(page_address(page), tag_storage);
+
+ ret = xa_store(&mte_pages, pfn, tag_storage, GFP_KERNEL);
+ if (WARN(xa_is_err(ret), "Failed to store MTE tags")) {
+ mte_free_tag_storage(tag_storage);
+ return xa_err(ret);
+ } else if (WARN(ret, "swsusp: %s: Duplicate entry", __func__)) {
+ mte_free_tag_storage(ret);
+ }
+
+ return 0;
+}
+
+static void swsusp_mte_free_storage(void)
+{
+ XA_STATE(xa_state, &mte_pages, 0);
+ void *tags;
+
+ xa_lock(&mte_pages);
+ xas_for_each(&xa_state, tags, ULONG_MAX) {
+ mte_free_tag_storage(tags);
+ }
+ xa_unlock(&mte_pages);
+
+ xa_destroy(&mte_pages);
+}
+
+static int swsusp_mte_save_tags(void)
+{
+ struct zone *zone;
+ unsigned long pfn, max_zone_pfn;
+ int ret = 0;
+ int n = 0;
+
+ if (!system_supports_mte())
+ return 0;
+
+ for_each_populated_zone(zone) {
+ max_zone_pfn = zone_end_pfn(zone);
+ for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) {
+ struct page *page = pfn_to_online_page(pfn);
+
+ if (!page)
+ continue;
+
+ if (!test_bit(PG_mte_tagged, &page->flags))
+ continue;
+
+ ret = save_tags(page, pfn);
+ n++;
+
+ if (ret) {
+ swsusp_mte_free_storage();
+ goto out;
+ }
+ }
+ }
+
+ pr_info("Saved %d MTE pages\n", n);
+
+out:
+ return ret;
+}
+
+static void swsusp_mte_restore_tags(void)
+{
+ XA_STATE(xa_state, &mte_pages, 0);
+ int n = 0;
+ void *tags;
+
+ xa_lock(&mte_pages);
+ xas_for_each(&xa_state, tags, ULONG_MAX) {
+ unsigned long pfn = xa_state.xa_index;
+ struct page *page = pfn_to_online_page(pfn);
+
+ mte_restore_page_tags(page_address(page), tags);
+
+ mte_free_tag_storage(tags);
+ n++;
+ }
+ xa_unlock(&mte_pages);
+
+ pr_info("Restored %d MTE pages\n", n);
+
+ xa_destroy(&mte_pages);
+}
+#else
+static int swsusp_mte_save_tags(void)
+{
+ return 0;
+}
+
+static void swsusp_mte_restore_tags(void)
+{
+}
+#endif
+
int swsusp_arch_suspend(void)
{
int ret = 0;
@@ -294,6 +404,10 @@ int swsusp_arch_suspend(void)
/* make the crash dump kernel image visible/saveable */
crash_prepare_suspend();
+ ret = swsusp_mte_save_tags();
+ if (ret)
+ return ret;
+
sleep_cpu = smp_processor_id();
ret = swsusp_save();
} else {
@@ -307,6 +421,8 @@ int swsusp_arch_suspend(void)
dcache_clean_range(__hyp_text_start, __hyp_text_end);
}
+ swsusp_mte_restore_tags();
+
/* make the crash dump kernel image protected again */
crash_post_resume();
When hibernating the contents of all pages in the system are written to disk, however the MTE tags are not visible to the generic hibernation code. So just before the hibernation image is created copy the tags out of the physical tag storage into standard memory so they will be included in the hibernation image. After hibernation apply the tags back into the physical tag storage. Signed-off-by: Steven Price <steven.price@arm.com> --- arch/arm64/kernel/hibernate.c | 116 ++++++++++++++++++++++++++++++++++ 1 file changed, 116 insertions(+)