+ x86-mm-pat-remove-memtype__match.patch added to mm-new branch

+ x86-mm-pat-remove-memtype__match.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: x86/mm/pat: remove MEMTYPE_*_MATCH
has been added to the -mm mm-new branch.  Its filename is
     x86-mm-pat-remove-memtype__match.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/x86-mm-pat-remove-memtype__match.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
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------------------------------------------------------
From: David Hildenbrand <david@redhat.com>
Subject: x86/mm/pat: remove MEMTYPE_*_MATCH
Date: Mon, 12 May 2025 14:34:21 +0200

The "memramp() shrinking" scenario no longer applies, so let's remove that
now-unnecessary handling.

Link: https://lkml.kernel.org/r/20250512123424.637989-9-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: Ingo Molnar <mingo@kernel.org> # x86 bits
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Dave Airlie <airlied@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Tvrtko Ursulin <tursulin@ursulin.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/x86/mm/pat/memtype_interval.c |   44 +++------------------------
 1 file changed, 6 insertions(+), 38 deletions(-)

--- a/arch/x86/mm/pat/memtype_interval.c~x86-mm-pat-remove-memtype__match
+++ a/arch/x86/mm/pat/memtype_interval.c
@@ -49,26 +49,15 @@ INTERVAL_TREE_DEFINE(struct memtype, rb,
 
 static struct rb_root_cached memtype_rbroot = RB_ROOT_CACHED;
 
-enum {
-	MEMTYPE_EXACT_MATCH	= 0,
-	MEMTYPE_END_MATCH	= 1
-};
-
-static struct memtype *memtype_match(u64 start, u64 end, int match_type)
+static struct memtype *memtype_match(u64 start, u64 end)
 {
 	struct memtype *entry_match;
 
 	entry_match = interval_iter_first(&memtype_rbroot, start, end-1);
 
 	while (entry_match != NULL && entry_match->start < end) {
-		if ((match_type == MEMTYPE_EXACT_MATCH) &&
-		    (entry_match->start == start) && (entry_match->end == end))
-			return entry_match;
-
-		if ((match_type == MEMTYPE_END_MATCH) &&
-		    (entry_match->start < start) && (entry_match->end == end))
+		if (entry_match->start == start && entry_match->end == end)
 			return entry_match;
-
 		entry_match = interval_iter_next(entry_match, start, end-1);
 	}
 
@@ -132,32 +121,11 @@ struct memtype *memtype_erase(u64 start,
 {
 	struct memtype *entry_old;
 
-	/*
-	 * Since the memtype_rbroot tree allows overlapping ranges,
-	 * memtype_erase() checks with EXACT_MATCH first, i.e. free
-	 * a whole node for the munmap case.  If no such entry is found,
-	 * it then checks with END_MATCH, i.e. shrink the size of a node
-	 * from the end for the mremap case.
-	 */
-	entry_old = memtype_match(start, end, MEMTYPE_EXACT_MATCH);
-	if (!entry_old) {
-		entry_old = memtype_match(start, end, MEMTYPE_END_MATCH);
-		if (!entry_old)
-			return ERR_PTR(-EINVAL);
-	}
-
-	if (entry_old->start == start) {
-		/* munmap: erase this node */
-		interval_remove(entry_old, &memtype_rbroot);
-	} else {
-		/* mremap: update the end value of this node */
-		interval_remove(entry_old, &memtype_rbroot);
-		entry_old->end = start;
-		interval_insert(entry_old, &memtype_rbroot);
-
-		return NULL;
-	}
+	entry_old = memtype_match(start, end);
+	if (!entry_old)
+		return ERR_PTR(-EINVAL);
 
+	interval_remove(entry_old, &memtype_rbroot);
 	return entry_old;
 }
 
_

Patches currently in -mm which might be from david@redhat.com are

selftests-mm-add-simple-vm_pfnmap-tests-based-on-mmaping-dev-mem.patch
x86-mm-pat-factor-out-setting-cachemode-into-pgprot_set_cachemode.patch
mm-convert-track_pfn_insert-to-pfnmap_setup_cachemode.patch
mm-introduce-pfnmap_track-and-pfnmap_untrack-and-use-them-for-memremap.patch
mm-convert-vm_pfnmap-tracking-to-pfnmap_track-pfnmap_untrack.patch
x86-mm-pat-remove-old-pfnmap-tracking-interface.patch
mm-remove-vm_pat.patch
x86-mm-pat-remove-strict_prot-parameter-from-reserve_pfn_range.patch
x86-mm-pat-remove-memtype__match.patch
x86-mm-pat-inline-memtype_match-into-memtype_erase.patch
drm-i915-track_pfn-pfnmap-tracking.patch
mm-io-mapping-track_pfn-pfnmap-tracking.patch