3 files changed, 53 insertions, 7 deletions

diff --git a/sys/vm/uma.h b/sys/vm/uma.h
index 954d64c4d63b..4225bd83ba23 100644
--- a/sys/vm/uma.h
+++ b/sys/vm/uma.h
@@ -470,12 +470,14 @@ void uma_zone_reclaim_domain(uma_zone_t, int req, int domain);
  * alignment.  Should be called by MD boot code prior to starting VM/UMA.
  *
  * Arguments:
- *	align The alignment mask
+ *	mask The alignment mask
  *
  * Returns:
  *	Nothing
  */
-void uma_set_align(int align);
+void uma_set_cache_align_mask(int mask);
+
+#include <vm/uma_align_mask.h>
 
 /*
  * Set a reserved number of items to hold for M_USE_RESERVE allocations.  All
diff --git a/sys/vm/uma_align_mask.h b/sys/vm/uma_align_mask.h
new file mode 100644
index 000000000000..666633350b9d
--- /dev/null
+++ b/sys/vm/uma_align_mask.h
@@ -0,0 +1,36 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2023 The FreeBSD Foundation
+ *
+ * This software was developed by Olivier Certner <olce.freebsd@certner.fr>
+ * at Kumacom SAS under sponsorship from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef _VM_UMA_ALIGN_MASK_H_
+#define _VM_UMA_ALIGN_MASK_H_
+
+int uma_get_cache_align_mask(void) __pure;
+
+#endif /* !_VM_UMA_ALIGN_MASK_H_ */
diff --git a/sys/vm/uma_core.c b/sys/vm/uma_core.c
index 679fd5ef1187..506bc63033ba 100644
--- a/sys/vm/uma_core.c
+++ b/sys/vm/uma_core.c
@@ -149,7 +149,7 @@ static uma_zone_t slabzones[2];
 static uma_zone_t hashzone;
 
 /* The boot-time adjusted value for cache line alignment. */
-int uma_align_cache = 64 - 1;
+static int uma_cache_align_mask = 64 - 1;
 
 static MALLOC_DEFINE(M_UMAHASH, "UMAHash", "UMA Hash Buckets");
 static MALLOC_DEFINE(M_UMA, "UMA", "UMA Misc");
@@ -3182,7 +3182,7 @@ uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
 	args.size = size;
 	args.uminit = uminit;
 	args.fini = fini;
-	args.align = (align == UMA_ALIGN_CACHE) ? uma_align_cache : align;
+	args.align = (align == UMA_ALIGN_CACHE) ? uma_cache_align_mask : align;
 	args.flags = flags;
 	args.zone = zone;
 	return (zone_alloc_item(kegs, &args, UMA_ANYDOMAIN, M_WAITOK));
@@ -3191,11 +3191,19 @@ uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
 /* Public functions */
 /* See uma.h */
 void
-uma_set_align(int align)
+uma_set_cache_align_mask(int mask)
 {
 
-	if (align != UMA_ALIGN_CACHE)
-		uma_align_cache = align;
+	if (mask >= 0)
+		/* UMA_ALIGN_CACHE is also not permitted here. */
+		uma_cache_align_mask = mask;
+}
+
+/* Returns the alignment mask to use to request cache alignment. */
+int
+uma_get_cache_align_mask(void)
+{
+	return (uma_cache_align_mask);
 }
 
 /* See uma.h */