kho: move alloc tag init to kho_init_{folio,pages}()

Commit 8f1081892d62 ("kho: simplify page initialization in
kho_restore_page()") cleaned up the page initialization logic by moving
the folio and 0-order-page paths into separate functions.  It missed
moving the alloc tag initialization.

Do it now to keep the two paths cleanly separated.  While at it, touch up
the comments to be a tiny bit shorter (mainly so it doesn't end up
splitting into a multiline comment).  This is purely a cosmetic change and
there should be no change in behaviour.

Link: https://lkml.kernel.org/r/20260213085914.2778107-1-pratyush@kernel.org
Signed-off-by: Pratyush Yadav (Google) <pratyush@kernel.org>
Cc: Alexander Graf <graf@amazon.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c
index cc68a3692905d8d6690a46c45f6d377edd5831e5..4356f277b462fffd158bae4e450b0183452c05fb 100644 (file)
--- a/kernel/liveupdate/kexec_handover.c
+++ b/kernel/liveupdate/kexec_handover.c
@@ -219,8 +219,11 @@ static int __kho_preserve_order(struct kho_mem_track *track, unsigned long pfn,
 /* For physically contiguous 0-order pages. */
 static void kho_init_pages(struct page *page, unsigned long nr_pages)
 {
-       for (unsigned long i = 0; i < nr_pages; i++)
+       for (unsigned long i = 0; i < nr_pages; i++) {
                set_page_count(page + i, 1);
+               /* Clear each page's codetag to avoid accounting mismatch. */
+               clear_page_tag_ref(page + i);
+       }
 }
 
 static void kho_init_folio(struct page *page, unsigned int order)
@@ -229,6 +232,8 @@ static void kho_init_folio(struct page *page, unsigned int order)
 
        /* Head page gets refcount of 1. */
        set_page_count(page, 1);
+       /* Clear head page's codetag to avoid accounting mismatch. */
+       clear_page_tag_ref(page);
 
        /* For higher order folios, tail pages get a page count of zero. */
        for (unsigned long i = 1; i < nr_pages; i++)
@@ -265,14 +270,6 @@ static struct page *kho_restore_page(phys_addr_t phys, bool is_folio)
        else
                kho_init_pages(page, nr_pages);
 
-       /* Always mark headpage's codetag as empty to avoid accounting mismatch */
-       clear_page_tag_ref(page);
-       if (!is_folio) {
-               /* Also do that for the non-compound tail pages */
-               for (unsigned int i = 1; i < nr_pages; i++)
-                       clear_page_tag_ref(page + i);
-       }
-
        adjust_managed_page_count(page, nr_pages);
        return page;
 }