Index: sys/amd64/include/vmparam.h
===================================================================
--- sys/amd64/include/vmparam.h
+++ sys/amd64/include/vmparam.h
@@ -253,4 +253,9 @@
  */
 #define	VM_BATCHQUEUE_SIZE	31
 
+/*
+ * The pmap can create non-transparent large page mappings.
+ */
+#define	PMAP_HAS_LARGEPAGES	1
+
 #endif /* _MACHINE_VMPARAM_H_ */
Index: sys/arm/include/vmparam.h
===================================================================
--- sys/arm/include/vmparam.h
+++ sys/arm/include/vmparam.h
@@ -193,4 +193,9 @@
 
 #define	DEVMAP_MAX_VADDR	ARM_VECTORS_HIGH
 
+/*
+ * No non-transparent large page support in the pmap.
+ */
+#define	PMAP_HAS_LARGEPAGES	0
+
 #endif	/* _MACHINE_VMPARAM_H_ */
Index: sys/arm64/include/vmparam.h
===================================================================
--- sys/arm64/include/vmparam.h
+++ sys/arm64/include/vmparam.h
@@ -243,4 +243,9 @@
 
 #define	DEVMAP_MAX_VADDR	VM_MAX_KERNEL_ADDRESS
 
+/*
+ * The pmap can create non-transparent large page mappings.
+ */
+#define	PMAP_HAS_LARGEPAGES	1
+
 #endif /* !_MACHINE_VMPARAM_H_ */
Index: sys/i386/include/vmparam.h
===================================================================
--- sys/i386/include/vmparam.h
+++ sys/i386/include/vmparam.h
@@ -240,4 +240,9 @@
 #define	PHYS_TO_DMAP(x)	({ panic("No direct map exists"); 0; })
 #define	DMAP_TO_PHYS(x)	({ panic("No direct map exists"); 0; })
 
+/*
+ * No non-transparent large page support in the pmap.
+ */
+#define	PMAP_HAS_LARGEPAGES	0
+
 #endif /* _MACHINE_VMPARAM_H_ */
Index: sys/kern/uipc_shm.c
===================================================================
--- sys/kern/uipc_shm.c
+++ sys/kern/uipc_shm.c
@@ -1067,7 +1067,7 @@
 		return (EINVAL);
 
 	largepage = (shmflags & SHM_LARGEPAGE) != 0;
-#if !defined(__amd64__)
+#if PMAP_HAS_LARGEPAGES == 0
 	if (largepage)
 		return (ENOTTY);
 #endif
Index: sys/mips/include/vmparam.h
===================================================================
--- sys/mips/include/vmparam.h
+++ sys/mips/include/vmparam.h
@@ -197,4 +197,9 @@
 #define	PHYS_TO_DMAP(x)	MIPS_PHYS_TO_DIRECT(x)
 #define	DMAP_TO_PHYS(x)	MIPS_DIRECT_TO_PHYS(x)
 
+/*
+ * No non-transparent large page support in the pmap.
+ */
+#define	PMAP_HAS_LARGEPAGES	0
+
 #endif /* !_MACHINE_VMPARAM_H_ */
Index: sys/powerpc/include/vmparam.h
===================================================================
--- sys/powerpc/include/vmparam.h
+++ sys/powerpc/include/vmparam.h
@@ -315,4 +315,9 @@
 	KASSERT(hw_direct_map, ("Direct map not provided by PMAP"));	\
 	(x) &~ DMAP_BASE_ADDRESS; })
 
+/*
+ * No non-transparent large page support in the pmap.
+ */
+#define	PMAP_HAS_LARGEPAGES	0
+
 #endif /* _MACHINE_VMPARAM_H_ */
Index: sys/riscv/include/vmparam.h
===================================================================
--- sys/riscv/include/vmparam.h
+++ sys/riscv/include/vmparam.h
@@ -236,4 +236,9 @@
 
 #define	DEVMAP_MAX_VADDR	VM_MAX_KERNEL_ADDRESS
 
+/*
+ * No non-transparent large page support in the pmap.
+ */
+#define	PMAP_HAS_LARGEPAGES	0
+
 #endif /* !_MACHINE_VMPARAM_H_ */