summaryrefslogtreecommitdiffstats
path: root/arch/arm64/mm/mteswap.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /arch/arm64/mm/mteswap.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm64/mm/mteswap.c')
-rw-r--r--arch/arm64/mm/mteswap.c85
1 files changed, 85 insertions, 0 deletions
diff --git a/arch/arm64/mm/mteswap.c b/arch/arm64/mm/mteswap.c
new file mode 100644
index 0000000000..a31833e3dd
--- /dev/null
+++ b/arch/arm64/mm/mteswap.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/pagemap.h>
+#include <linux/xarray.h>
+#include <linux/slab.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <asm/mte.h>
+
+static DEFINE_XARRAY(mte_pages);
+
+void *mte_allocate_tag_storage(void)
+{
+ /* tags granule is 16 bytes, 2 tags stored per byte */
+ return kmalloc(MTE_PAGE_TAG_STORAGE, GFP_KERNEL);
+}
+
+void mte_free_tag_storage(char *storage)
+{
+ kfree(storage);
+}
+
+int mte_save_tags(struct page *page)
+{
+ void *tag_storage, *ret;
+
+ if (!page_mte_tagged(page))
+ return 0;
+
+ tag_storage = mte_allocate_tag_storage();
+ if (!tag_storage)
+ return -ENOMEM;
+
+ mte_save_page_tags(page_address(page), tag_storage);
+
+ /* lookup the swap entry.val from the page */
+ ret = xa_store(&mte_pages, page_swap_entry(page).val, 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 (ret) {
+ /* Entry is being replaced, free the old entry */
+ mte_free_tag_storage(ret);
+ }
+
+ return 0;
+}
+
+void mte_restore_tags(swp_entry_t entry, struct page *page)
+{
+ void *tags = xa_load(&mte_pages, entry.val);
+
+ if (!tags)
+ return;
+
+ if (try_page_mte_tagging(page)) {
+ mte_restore_page_tags(page_address(page), tags);
+ set_page_mte_tagged(page);
+ }
+}
+
+void mte_invalidate_tags(int type, pgoff_t offset)
+{
+ swp_entry_t entry = swp_entry(type, offset);
+ void *tags = xa_erase(&mte_pages, entry.val);
+
+ mte_free_tag_storage(tags);
+}
+
+void mte_invalidate_tags_area(int type)
+{
+ swp_entry_t entry = swp_entry(type, 0);
+ swp_entry_t last_entry = swp_entry(type + 1, 0);
+ void *tags;
+
+ XA_STATE(xa_state, &mte_pages, entry.val);
+
+ xa_lock(&mte_pages);
+ xas_for_each(&xa_state, tags, last_entry.val - 1) {
+ __xa_erase(&mte_pages, xa_state.xa_index);
+ mte_free_tag_storage(tags);
+ }
+ xa_unlock(&mte_pages);
+}