[PATCH RFC 03/37] arm64: mte: Rename __GFP_ZEROTAGS to __GFP_TAGGED

Alexandru Elisei
2023-08-23T13:14:34Z

__GFP_ZEROTAGS is used to instruct the page allocator to zero the tags at
the same time as the physical frame is zeroed. The name can be slightly
misleading, because it doesn't mean that the code will zero the tags
unconditionally, but that the tags will be zeroed if and only if the
physical frame is also zeroed (either __GFP_ZERO is set or init_on_alloc is
1).

Rename it to __GFP_TAGGED, in preparation for it to be used by the page
allocator to recognize when an allocation is tagged (has metadata).

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
---
arch/arm64/mm/fault.c | 2 +-
include/linux/gfp_types.h | 14 +++++++-------
include/trace/events/mmflags.h | 2 +-
mm/page_alloc.c | 2 +-
4 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 3fe516b32577..0ca89ebcdc63 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -949,7 +949,7 @@ struct folio *vma_alloc_zeroed_movable_folio(struct vm_area_struct *vma,
* separate DC ZVA and STGM.
*/
if (vma->vm_flags & VM_MTE)
- flags |= __GFP_ZEROTAGS;
+ flags |= __GFP_TAGGED;

return vma_alloc_folio(flags, 0, vma, vaddr, false);
}
diff --git a/include/linux/gfp_types.h b/include/linux/gfp_types.h
index 6583a58670c5..37b9e265d77e 100644
--- a/include/linux/gfp_types.h
+++ b/include/linux/gfp_types.h
@@ -45,7 +45,7 @@ typedef unsigned int __bitwise gfp_t;
#define ___GFP_HARDWALL 0x100000u
#define ___GFP_THISNODE 0x200000u
#define ___GFP_ACCOUNT 0x400000u
-#define ___GFP_ZEROTAGS 0x800000u
+#define ___GFP_TAGGED 0x800000u
#ifdef CONFIG_KASAN_HW_TAGS
#define ___GFP_SKIP_ZERO 0x1000000u
#define ___GFP_SKIP_KASAN 0x2000000u
@@ -226,11 +226,11 @@ typedef unsigned int __bitwise gfp_t;
*
* %__GFP_ZERO returns a zeroed page on success.
*
- * %__GFP_ZEROTAGS zeroes memory tags at allocation time if the memory itself
- * is being zeroed (either via __GFP_ZERO or via init_on_alloc, provided that
- * __GFP_SKIP_ZERO is not set). This flag is intended for optimization: setting
- * memory tags at the same time as zeroing memory has minimal additional
- * performace impact.
+ * %__GFP_TAGGED marks the allocation as having tags, which will be zeroed it
+ * allocation time if the memory itself is being zeroed (either via __GFP_ZERO
+ * or via init_on_alloc, provided that __GFP_SKIP_ZERO is not set). This flag is
+ * intended for optimization: setting memory tags at the same time as zeroing
+ * memory has minimal additional performace impact.
*
* %__GFP_SKIP_KASAN makes KASAN skip unpoisoning on page allocation.
* Used for userspace and vmalloc pages; the latter are unpoisoned by
@@ -241,7 +241,7 @@ typedef unsigned int __bitwise gfp_t;
#define __GFP_NOWARN ((__force gfp_t)___GFP_NOWARN)
#define __GFP_COMP ((__force gfp_t)___GFP_COMP)
#define __GFP_ZERO ((__force gfp_t)___GFP_ZERO)
-#define __GFP_ZEROTAGS ((__force gfp_t)___GFP_ZEROTAGS)
+#define __GFP_TAGGED ((__force gfp_t)___GFP_TAGGED)
#define __GFP_SKIP_ZERO ((__force gfp_t)___GFP_SKIP_ZERO)
#define __GFP_SKIP_KASAN ((__force gfp_t)___GFP_SKIP_KASAN)

diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h
index 1478b9dd05fa..4ccca8e73c93 100644
--- a/include/trace/events/mmflags.h
+++ b/include/trace/events/mmflags.h
@@ -50,7 +50,7 @@
gfpflag_string(__GFP_RECLAIM), \
gfpflag_string(__GFP_DIRECT_RECLAIM), \
gfpflag_string(__GFP_KSWAPD_RECLAIM), \
- gfpflag_string(__GFP_ZEROTAGS)
+ gfpflag_string(__GFP_TAGGED)

#ifdef CONFIG_KASAN_HW_TAGS
#define __def_gfpflag_names_kasan , \
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e6f950c54494..fdc230440a44 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1516,7 +1516,7 @@ inline void post_alloc_hook(struct page *page, unsigned int order,
{
bool init = !want_init_on_free() && want_init_on_alloc(gfp_flags) &&
!should_skip_init(gfp_flags);
- bool zero_tags = init && (gfp_flags & __GFP_ZEROTAGS);
+ bool zero_tags = init && (gfp_flags & __GFP_TAGGED);
int i;

set_page_private(page, 0);
--
2.41.0