x86/mm/pat: remove MEMTYPE_*_MATCH

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]
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
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: "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>

diff --git a/arch/x86/mm/pat/memtype_interval.c b/arch/x86/mm/pat/memtype_interval.c
index 645613d59942a31dd9d8c42d360d90a59156f592..9d03f0dbc47153594dba324f1b867b07f5daae73 100644 (file)
--- a/arch/x86/mm/pat/memtype_interval.c
+++ b/arch/x86/mm/pat/memtype_interval.c
@@ -49,26 +49,15 @@ INTERVAL_TREE_DEFINE(struct memtype, rb, u64, subtree_max_end,
 
 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, u64 end)
 {
        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;
 }