35 files changed, 69 insertions, 96 deletions

diff --git a/sys/amd64/amd64/sys_machdep.c b/sys/amd64/amd64/sys_machdep.c
index 63f4d7c72346a..b1dff88a584e8 100644
--- a/sys/amd64/amd64/sys_machdep.c
+++ b/sys/amd64/amd64/sys_machdep.c
@@ -479,7 +479,7 @@ user_ldt_alloc(struct proc *p, int force)
 	pldt = mdp->md_ldt;
 	if (pldt != NULL && !force) {
 		pmap_pti_remove_kva(sva, sva + sz);
-		kmem_free(kernel_arena, sva, sz);
+		kmem_free(sva, sz);
 		free(new_ldt, M_SUBPROC);
 		return (pldt);
 	}
@@ -533,7 +533,7 @@ user_ldt_derefl(struct proc_ldt *pldt)
 		sva = (vm_offset_t)pldt->ldt_base;
 		sz = max_ldt_segment * sizeof(struct user_segment_descriptor);
 		pmap_pti_remove_kva(sva, sva + sz);
-		kmem_free(kernel_arena, sva, sz);
+		kmem_free(sva, sz);
 		free(pldt, M_SUBPROC);
 	}
 }
diff --git a/sys/amd64/amd64/vm_machdep.c b/sys/amd64/amd64/vm_machdep.c
index c7a18ce067168..ba71d5127cd81 100644
--- a/sys/amd64/amd64/vm_machdep.c
+++ b/sys/amd64/amd64/vm_machdep.c
@@ -331,8 +331,7 @@ cpu_thread_clean(struct thread *td)
 	if (pcb->pcb_tssp != NULL) {
 		pmap_pti_remove_kva((vm_offset_t)pcb->pcb_tssp,
 		    (vm_offset_t)pcb->pcb_tssp + ctob(IOPAGES + 1));
-		kmem_free(kernel_arena, (vm_offset_t)pcb->pcb_tssp,
-		    ctob(IOPAGES + 1));
+		kmem_free((vm_offset_t)pcb->pcb_tssp, ctob(IOPAGES + 1));
 		pcb->pcb_tssp = NULL;
 	}
 }
diff --git a/sys/arm/allwinner/a10_fb.c b/sys/arm/allwinner/a10_fb.c
index ef3899b3c3686..6342eb0acf469 100644
--- a/sys/arm/allwinner/a10_fb.c
+++ b/sys/arm/allwinner/a10_fb.c
@@ -192,7 +192,7 @@ a10fb_allocfb(struct a10fb_softc *sc)
 static void
 a10fb_freefb(struct a10fb_softc *sc)
 {
-	kmem_free(kernel_arena, sc->vaddr, sc->fbsize);
+	kmem_free(sc->vaddr, sc->fbsize);
 }
 
 static int
diff --git a/sys/arm/arm/busdma_machdep-v4.c b/sys/arm/arm/busdma_machdep-v4.c
index e6e863ad9ca63..d7ab11ff07a0b 100644
--- a/sys/arm/arm/busdma_machdep-v4.c
+++ b/sys/arm/arm/busdma_machdep-v4.c
@@ -792,7 +792,7 @@ bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 	    !_bus_dma_can_bounce(dmat->lowaddr, dmat->highaddr))
 		uma_zfree(bufzone->umazone, vaddr);
 	else
-		kmem_free(kernel_arena, (vm_offset_t)vaddr, dmat->maxsize);
+		kmem_free((vm_offset_t)vaddr, dmat->maxsize);
 
 	dmat->map_count--;
 	if (map->flags & DMAMAP_COHERENT)
diff --git a/sys/arm/arm/busdma_machdep-v6.c b/sys/arm/arm/busdma_machdep-v6.c
index 3ab34fb3322a3..2aff3f8a1502f 100644
--- a/sys/arm/arm/busdma_machdep-v6.c
+++ b/sys/arm/arm/busdma_machdep-v6.c
@@ -858,7 +858,7 @@ bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 	    !exclusion_bounce(dmat))
 		uma_zfree(bufzone->umazone, vaddr);
 	else
-		kmem_free(kernel_arena, (vm_offset_t)vaddr, dmat->maxsize);
+		kmem_free((vm_offset_t)vaddr, dmat->maxsize);
 
 	dmat->map_count--;
 	if (map->flags & DMAMAP_COHERENT)
diff --git a/sys/arm/arm/pmap-v6.c b/sys/arm/arm/pmap-v6.c
index 90c383ee7bcad..8dd74f15d9252 100644
--- a/sys/arm/arm/pmap-v6.c
+++ b/sys/arm/arm/pmap-v6.c
@@ -2242,8 +2242,7 @@ pmap_pinit(pmap_t pmap)
 			 *      UMA_ZONE_NOFREE flag, it's important to leave
 			 *      no allocation in pmap if initialization failed.
 			 */
-			kmem_free(kernel_arena, (vm_offset_t)pmap->pm_pt1,
-			    NB_IN_PT1);
+			kmem_free((vm_offset_t)pmap->pm_pt1, NB_IN_PT1);
 			pmap->pm_pt1 = NULL;
 			return (0);
 		}
diff --git a/sys/arm/freescale/imx/imx6_sdma.c b/sys/arm/freescale/imx/imx6_sdma.c
index 6566151e68a46..3bae225a75d55 100644
--- a/sys/arm/freescale/imx/imx6_sdma.c
+++ b/sys/arm/freescale/imx/imx6_sdma.c
@@ -196,8 +196,7 @@ sdma_free(int chn)
 	channel = &sc->channel[chn];
 	channel->in_use = 0;
 
-	kmem_free(kernel_arena, (vm_offset_t)channel->bd,
-			PAGE_SIZE);
+	kmem_free((vm_offset_t)channel->bd, PAGE_SIZE);
 
 	return (0);
 }
diff --git a/sys/arm/nvidia/tegra_xhci.c b/sys/arm/nvidia/tegra_xhci.c
index f3d96752cc877..7615e8809e61f 100644
--- a/sys/arm/nvidia/tegra_xhci.c
+++ b/sys/arm/nvidia/tegra_xhci.c
@@ -984,7 +984,7 @@ tegra_xhci_detach(device_t dev)
 	if (sc->irq_hdl_mbox != NULL)
 		bus_teardown_intr(dev, sc->irq_res_mbox, sc->irq_hdl_mbox);
 	if (sc->fw_vaddr != 0)
-		kmem_free(kernel_arena, sc->fw_vaddr, sc->fw_size);
+		kmem_free(sc->fw_vaddr, sc->fw_size);
 	LOCK_DESTROY(sc);
 	return (0);
 }
diff --git a/sys/arm64/arm64/busdma_bounce.c b/sys/arm64/arm64/busdma_bounce.c
index 0459fbc08a936..07894652ade89 100644
--- a/sys/arm64/arm64/busdma_bounce.c
+++ b/sys/arm64/arm64/busdma_bounce.c
@@ -532,8 +532,7 @@ bounce_bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 	if ((dmat->bounce_flags & BF_KMEM_ALLOC) == 0)
 		free(vaddr, M_DEVBUF);
 	else
-		kmem_free(kernel_arena, (vm_offset_t)vaddr,
-		    dmat->common.maxsize);
+		kmem_free((vm_offset_t)vaddr, dmat->common.maxsize);
 	free(map, M_DEVBUF);
 	dmat->map_count--;
 	CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat,
diff --git a/sys/arm64/arm64/mp_machdep.c b/sys/arm64/arm64/mp_machdep.c
index a3f096f607175..aa067d0194e4c 100644
--- a/sys/arm64/arm64/mp_machdep.c
+++ b/sys/arm64/arm64/mp_machdep.c
@@ -502,8 +502,7 @@ start_cpu(u_int id, uint64_t target_cpu)
 		    ("Failed to start CPU %u (%lx)\n", id, target_cpu));
 
 		pcpu_destroy(pcpup);
-		kmem_free(kernel_arena, (vm_offset_t)dpcpu[cpuid - 1],
-		    DPCPU_SIZE);
+		kmem_free((vm_offset_t)dpcpu[cpuid - 1], DPCPU_SIZE);
 		dpcpu[cpuid - 1] = NULL;
 		mp_ncpus--;
 
diff --git a/sys/compat/linuxkpi/common/include/linux/dma-mapping.h b/sys/compat/linuxkpi/common/include/linux/dma-mapping.h
index bae94a4fbc5a5..f482ccb3b53e4 100644
--- a/sys/compat/linuxkpi/common/include/linux/dma-mapping.h
+++ b/sys/compat/linuxkpi/common/include/linux/dma-mapping.h
@@ -156,7 +156,7 @@ dma_free_coherent(struct device *dev, size_t size, void *cpu_addr,
     dma_addr_t dma_handle)
 {
 
-	kmem_free(kmem_arena, (vm_offset_t)cpu_addr, size);
+	kmem_free((vm_offset_t)cpu_addr, size);
 }
 
 /* XXX This only works with no iommu. */
diff --git a/sys/compat/linuxkpi/common/src/linux_page.c b/sys/compat/linuxkpi/common/src/linux_page.c
index b65b29e345d98..63564f42a16c6 100644
--- a/sys/compat/linuxkpi/common/src/linux_page.c
+++ b/sys/compat/linuxkpi/common/src/linux_page.c
@@ -178,7 +178,7 @@ linux_free_kmem(vm_offset_t addr, unsigned int order)
 {
 	size_t size = ((size_t)PAGE_SIZE) << order;
 
-	kmem_free(kmem_arena, addr, size);
+	kmem_free(addr, size);
 }
 
 static int
diff --git a/sys/dev/agp/agp.c b/sys/dev/agp/agp.c
index fca63f9666ae8..011c89afeb371 100644
--- a/sys/dev/agp/agp.c
+++ b/sys/dev/agp/agp.c
@@ -171,8 +171,8 @@ agp_alloc_gatt(device_t dev)
 void
 agp_free_gatt(struct agp_gatt *gatt)
 {
-	kmem_free(kernel_arena, (vm_offset_t)gatt->ag_virtual,
-	    gatt->ag_entries * sizeof(u_int32_t));
+	kmem_free((vm_offset_t)gatt->ag_virtual, gatt->ag_entries *
+	    sizeof(u_int32_t));
 	free(gatt, M_AGP);
 }
 
diff --git a/sys/dev/agp/agp_amd.c b/sys/dev/agp/agp_amd.c
index 1648f41ac4a0f..8307d8d9d7974 100644
--- a/sys/dev/agp/agp_amd.c
+++ b/sys/dev/agp/agp_amd.c
@@ -119,8 +119,8 @@ agp_amd_alloc_gatt(device_t dev)
 		if (bootverbose)
 			device_printf(dev,
 				      "failed to allocate page directory\n");
-		kmem_free(kernel_arena, (vm_offset_t)gatt->ag_virtual,
-		    entries * sizeof(u_int32_t));
+		kmem_free((vm_offset_t)gatt->ag_virtual, entries *
+		    sizeof(u_int32_t));
 		free(gatt, M_AGP);
 		return 0;
 	}
@@ -168,9 +168,9 @@ agp_amd_alloc_gatt(device_t dev)
 static void
 agp_amd_free_gatt(struct agp_amd_gatt *gatt)
 {
-	kmem_free(kernel_arena, (vm_offset_t)gatt->ag_vdir, AGP_PAGE_SIZE);
-	kmem_free(kernel_arena, (vm_offset_t)gatt->ag_virtual,
-	    gatt->ag_entries * sizeof(u_int32_t));
+	kmem_free((vm_offset_t)gatt->ag_vdir, AGP_PAGE_SIZE);
+	kmem_free((vm_offset_t)gatt->ag_virtual, gatt->ag_entries *
+	    sizeof(u_int32_t));
 	free(gatt, M_AGP);
 }
 
diff --git a/sys/dev/agp/agp_ati.c b/sys/dev/agp/agp_ati.c
index d6c10dc66349c..6dc2746f144e5 100644
--- a/sys/dev/agp/agp_ati.c
+++ b/sys/dev/agp/agp_ati.c
@@ -147,8 +147,8 @@ agp_ati_alloc_gatt(device_t dev)
 	if (sc->ag_vdir == NULL) {
 		if (bootverbose)
 			device_printf(dev, "pagedir allocation failed\n");
-		kmem_free(kernel_arena, (vm_offset_t)sc->ag_virtual,
-		    entries * sizeof(u_int32_t));
+		kmem_free((vm_offset_t)sc->ag_virtual, entries *
+		    sizeof(u_int32_t));
 		return ENOMEM;
 	}
 	sc->ag_pdir = vtophys((vm_offset_t)sc->ag_vdir);
@@ -265,9 +265,9 @@ agp_ati_detach(device_t dev)
 	temp = pci_read_config(dev, apsize_reg, 4);
 	pci_write_config(dev, apsize_reg, temp & ~1, 4);
 
-	kmem_free(kernel_arena, (vm_offset_t)sc->ag_vdir, AGP_PAGE_SIZE);
-	kmem_free(kernel_arena, (vm_offset_t)sc->ag_virtual,
-	    sc->ag_entries * sizeof(u_int32_t));
+	kmem_free((vm_offset_t)sc->ag_vdir, AGP_PAGE_SIZE);
+	kmem_free((vm_offset_t)sc->ag_virtual, sc->ag_entries *
+	    sizeof(u_int32_t));
 
 	bus_release_resource(dev, SYS_RES_MEMORY, ATI_GART_MMADDR, sc->regs);
 	agp_free_res(dev);
diff --git a/sys/dev/agp/agp_i810.c b/sys/dev/agp/agp_i810.c
index 59028f0533d85..27d7f1114a089 100644
--- a/sys/dev/agp/agp_i810.c
+++ b/sys/dev/agp/agp_i810.c
@@ -1329,7 +1329,7 @@ agp_i810_deinstall_gatt(device_t dev)
 
 	sc = device_get_softc(dev);
 	bus_write_4(sc->sc_res[0], AGP_I810_PGTBL_CTL, 0);
-	kmem_free(kernel_arena, (vm_offset_t)sc->gatt->ag_virtual, 64 * 1024);
+	kmem_free((vm_offset_t)sc->gatt->ag_virtual, 64 * 1024);
 }
 
 static void
diff --git a/sys/dev/amd_ecc_inject/ecc_inject.c b/sys/dev/amd_ecc_inject/ecc_inject.c
index a682115b08ae5..7425320f8256a 100644
--- a/sys/dev/amd_ecc_inject/ecc_inject.c
+++ b/sys/dev/amd_ecc_inject/ecc_inject.c
@@ -195,7 +195,7 @@ ecc_ei_inject(int count)
 			pause_sbt("ecc_ei_inject", delay_ms * SBT_1MS, 0, 0);
 	}
 
-	kmem_free(kernel_arena, memory, PAGE_SIZE);
+	kmem_free(memory, PAGE_SIZE);
 }
 
 static int
diff --git a/sys/dev/drm/drm_scatter.c b/sys/dev/drm/drm_scatter.c
index 163634878d938..9b02d1a69c550 100644
--- a/sys/dev/drm/drm_scatter.c
+++ b/sys/dev/drm/drm_scatter.c
@@ -99,7 +99,7 @@ drm_sg_cleanup(struct drm_sg_mem *entry)
 		return;
 
 	if (entry->vaddr != 0)
-		kmem_free(kernel_arena, entry->vaddr, IDX_TO_OFF(entry->pages));
+		kmem_free(entry->vaddr, IDX_TO_OFF(entry->pages));
 
 	free(entry->busaddr, DRM_MEM_SGLISTS);
 	free(entry, DRM_MEM_DRIVER);
diff --git a/sys/dev/drm2/drm_scatter.c b/sys/dev/drm2/drm_scatter.c
index 510fce4cd6a4d..1ccc88a5f69c4 100644
--- a/sys/dev/drm2/drm_scatter.c
+++ b/sys/dev/drm2/drm_scatter.c
@@ -47,7 +47,7 @@ void drm_sg_cleanup(struct drm_sg_mem * entry)
 		return;
 
 	if (entry->vaddr != 0)
-		kmem_free(kernel_arena, entry->vaddr, IDX_TO_OFF(entry->pages));
+		kmem_free(entry->vaddr, IDX_TO_OFF(entry->pages));
 
 	free(entry->busaddr, DRM_MEM_SGLISTS);
 	free(entry, DRM_MEM_DRIVER);
diff --git a/sys/dev/hyperv/vmbus/hyperv.c b/sys/dev/hyperv/vmbus/hyperv.c
index d2d252ded07cc..5bb38fde8241e 100644
--- a/sys/dev/hyperv/vmbus/hyperv.c
+++ b/sys/dev/hyperv/vmbus/hyperv.c
@@ -264,8 +264,7 @@ SYSINIT(hyperv_initialize, SI_SUB_HYPERVISOR, SI_ORDER_FIRST, hyperv_init,
 static void
 hypercall_memfree(void)
 {
-	kmem_free(kernel_arena, (vm_offset_t)hypercall_context.hc_addr,
-	    PAGE_SIZE);
+	kmem_free((vm_offset_t)hypercall_context.hc_addr, PAGE_SIZE);
 	hypercall_context.hc_addr = NULL;
 }
 
diff --git a/sys/dev/liquidio/lio_network.h b/sys/dev/liquidio/lio_network.h
index b8cdcde76626d..b1f4e1448fe9d 100644
--- a/sys/dev/liquidio/lio_network.h
+++ b/sys/dev/liquidio/lio_network.h
@@ -212,7 +212,7 @@ static inline void
 lio_dma_free(size_t size, void *cpu_addr)
 {
 
-	kmem_free(kmem_arena, (vm_offset_t)cpu_addr, size);
+	kmem_free((vm_offset_t)cpu_addr, size);
 }
 
 static inline uint64_t
diff --git a/sys/kern/kern_malloc.c b/sys/kern/kern_malloc.c
index 0269298b6a0e5..c102eb52e5bd1 100644
--- a/sys/kern/kern_malloc.c
+++ b/sys/kern/kern_malloc.c
@@ -475,7 +475,7 @@ void
 contigfree(void *addr, unsigned long size, struct malloc_type *type)
 {
 
-	kmem_free(kernel_arena, (vm_offset_t)addr, size);
+	kmem_free((vm_offset_t)addr, size);
 	malloc_type_freed(type, round_page(size));
 }
 
diff --git a/sys/kern/subr_busdma_bufalloc.c b/sys/kern/subr_busdma_bufalloc.c
index c449e8820e7b6..52d1388ba7fcf 100644
--- a/sys/kern/subr_busdma_bufalloc.c
+++ b/sys/kern/subr_busdma_bufalloc.c
@@ -171,6 +171,6 @@ void
 busdma_bufalloc_free_uncacheable(void *item, vm_size_t size, uint8_t pflag)
 {
 
-	kmem_free(kernel_arena, (vm_offset_t)item, size);
+	kmem_free((vm_offset_t)item, size);
 }
 
diff --git a/sys/mips/ingenic/jz4780_lcd.c b/sys/mips/ingenic/jz4780_lcd.c
index 506c23e601216..77327fc093ac7 100644
--- a/sys/mips/ingenic/jz4780_lcd.c
+++ b/sys/mips/ingenic/jz4780_lcd.c
@@ -129,7 +129,7 @@ jzlcd_allocfb(struct jzlcd_softc *sc)
 static void
 jzlcd_freefb(struct jzlcd_softc *sc)
 {
-	kmem_free(kernel_arena, sc->vaddr, sc->fbsize);
+	kmem_free(sc->vaddr, sc->fbsize);
 }
 
 static void
diff --git a/sys/mips/mips/busdma_machdep.c b/sys/mips/mips/busdma_machdep.c
index 46ad2c248633b..84967b12d53a2 100644
--- a/sys/mips/mips/busdma_machdep.c
+++ b/sys/mips/mips/busdma_machdep.c
@@ -756,7 +756,7 @@ bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 	    !_bus_dma_can_bounce(dmat->lowaddr, dmat->highaddr))
 		uma_zfree(bufzone->umazone, vaddr);
 	else
-		kmem_free(kernel_arena, (vm_offset_t)vaddr, dmat->maxsize);
+		kmem_free((vm_offset_t)vaddr, dmat->maxsize);
 	CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat, dmat->flags);
 }
 
diff --git a/sys/powerpc/powerpc/busdma_machdep.c b/sys/powerpc/powerpc/busdma_machdep.c
index 78c3568785c68..cc5212198da65 100644
--- a/sys/powerpc/powerpc/busdma_machdep.c
+++ b/sys/powerpc/powerpc/busdma_machdep.c
@@ -570,7 +570,7 @@ bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 	if (!map->contigalloc)
 		free(vaddr, M_DEVBUF);
 	else
-		kmem_free(kmem_arena, (vm_offset_t)vaddr, dmat->maxsize);
+		kmem_free((vm_offset_t)vaddr, dmat->maxsize);
 	bus_dmamap_destroy(dmat, map);
 	CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat, dmat->flags);
 }
diff --git a/sys/vm/uma.h b/sys/vm/uma.h
index 87ace146bad27..06a3f3545cfbd 100644
--- a/sys/vm/uma.h
+++ b/sys/vm/uma.h
@@ -616,12 +616,11 @@ void uma_zone_set_freef(uma_zone_t zone, uma_free freef);
  * These flags are setable in the allocf and visible in the freef.
  */
 #define UMA_SLAB_BOOT	0x01		/* Slab alloced from boot pages */
-#define UMA_SLAB_KRWX	0x02		/* Slab alloced from kernel_rwx_arena */
-#define UMA_SLAB_KERNEL	0x04		/* Slab alloced from kernel_map */
+#define UMA_SLAB_KERNEL	0x04		/* Slab alloced from kmem */
 #define UMA_SLAB_PRIV	0x08		/* Slab alloced from priv allocator */
 #define UMA_SLAB_OFFP	0x10		/* Slab is managed separately  */
 #define UMA_SLAB_MALLOC	0x20		/* Slab is a large malloc slab */
-/* 0x40 and 0x80 are available */
+/* 0x02, 0x40, and 0x80 are available */
 
 /*
  * Used to pre-fill a zone with some number of items
diff --git a/sys/vm/uma_core.c b/sys/vm/uma_core.c
index 84710963dbc53..d971c3c76a619 100644
--- a/sys/vm/uma_core.c
+++ b/sys/vm/uma_core.c
@@ -1300,14 +1300,11 @@ noobj_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *flags,
 static void
 page_free(void *mem, vm_size_t size, uint8_t flags)
 {
-	struct vmem *vmem;
 
-	if (flags & UMA_SLAB_KERNEL)
-		vmem = kernel_arena;
-	else
+	if ((flags & UMA_SLAB_KERNEL) == 0)
 		panic("UMA: page_free used with invalid flags %x", flags);
 
-	kmem_free(vmem, (vm_offset_t)mem, size);
+	kmem_free((vm_offset_t)mem, size);
 }
 
 /*
@@ -3694,10 +3691,6 @@ uma_large_malloc_domain(vm_size_t size, int domain, int wait)
 		vsetslab(addr, slab);
 		slab->us_data = (void *)addr;
 		slab->us_flags = UMA_SLAB_KERNEL | UMA_SLAB_MALLOC;
-#if VM_NRESERVLEVEL > 0
-		if (__predict_false((wait & M_EXEC) != 0))
-			slab->us_flags |= UMA_SLAB_KRWX;
-#endif
 		slab->us_size = size;
 		slab->us_domain = vm_phys_domain(PHYS_TO_VM_PAGE(
 		    pmap_kextract(addr)));
@@ -3719,19 +3712,10 @@ uma_large_malloc(vm_size_t size, int wait)
 void
 uma_large_free(uma_slab_t slab)
 {
-	struct vmem *arena;
 
 	KASSERT((slab->us_flags & UMA_SLAB_KERNEL) != 0,
 	    ("uma_large_free:  Memory not allocated with uma_large_malloc."));
-#if VM_NRESERVLEVEL > 0
-	if (__predict_true((slab->us_flags & UMA_SLAB_KRWX) == 0))
-		arena = kernel_arena;
-	else
-		arena = kernel_rwx_arena;
-#else
-	arena = kernel_arena;
-#endif
-	kmem_free(arena, (vm_offset_t)slab->us_data, slab->us_size);
+	kmem_free((vm_offset_t)slab->us_data, slab->us_size);
 	uma_total_dec(slab->us_size);
 	zone_free_item(slabzone, slab, NULL, SKIP_NONE);
 }
diff --git a/sys/vm/vm_extern.h b/sys/vm/vm_extern.h
index b2747769496f6..3174e645c8be1 100644
--- a/sys/vm/vm_extern.h
+++ b/sys/vm/vm_extern.h
@@ -66,7 +66,7 @@ vm_offset_t kmem_alloc_contig_domain(int domain, vm_size_t size, int flags,
     vm_memattr_t memattr);
 vm_offset_t kmem_malloc(vm_size_t size, int flags);
 vm_offset_t kmem_malloc_domain(int domain, vm_size_t size, int flags);
-void kmem_free(struct vmem *, vm_offset_t, vm_size_t);
+void kmem_free(vm_offset_t addr, vm_size_t size);
 
 /* This provides memory for previously allocated address space. */
 int kmem_back(vm_object_t, vm_offset_t, vm_size_t, int);
diff --git a/sys/vm/vm_kern.c b/sys/vm/vm_kern.c
index 38800c6d26686..5dee4d758dd02 100644
--- a/sys/vm/vm_kern.c
+++ b/sys/vm/vm_kern.c
@@ -462,6 +462,10 @@ retry:
 		m->valid = VM_PAGE_BITS_ALL;
 		pmap_enter(kernel_pmap, addr + i, m, prot,
 		    prot | PMAP_ENTER_WIRED, 0);
+#if VM_NRESERVLEVEL > 0
+		if (__predict_false((prot & VM_PROT_EXECUTE) != 0))
+			m->oflags |= VPO_KMEM_EXEC;
+#endif
 	}
 	VM_OBJECT_WUNLOCK(object);
 
@@ -497,9 +501,10 @@ kmem_back(vm_object_t object, vm_offset_t addr, vm_size_t size, int flags)
  *	A physical page must exist within the specified object at each index
  *	that is being unmapped.
  */
-static int
+static struct vmem *
 _kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size)
 {
+	struct vmem *arena;
 	vm_page_t m, next;
 	vm_offset_t end, offset;
 	int domain;
@@ -508,13 +513,21 @@ _kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size)
 	    ("kmem_unback: only supports kernel object."));
 
 	if (size == 0)
-		return (0);
+		return (NULL);
 	pmap_remove(kernel_pmap, addr, addr + size);
 	offset = addr - VM_MIN_KERNEL_ADDRESS;
 	end = offset + size;
 	VM_OBJECT_WLOCK(object);
 	m = vm_page_lookup(object, atop(offset)); 
 	domain = vm_phys_domain(m);
+#if VM_NRESERVLEVEL > 0
+	if (__predict_true((m->oflags & VPO_KMEM_EXEC) == 0))
+		arena = vm_dom[domain].vmd_kernel_arena;
+	else
+		arena = vm_dom[domain].vmd_kernel_rwx_arena;
+#else
+	arena = vm_dom[domain].vmd_kernel_arena;
+#endif
 	for (; offset < end; offset += PAGE_SIZE, m = next) {
 		next = vm_page_next(m);
 		vm_page_unwire(m, PQ_NONE);
@@ -522,14 +535,14 @@ _kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size)
 	}
 	VM_OBJECT_WUNLOCK(object);
 
-	return (domain);
+	return (arena);
 }
 
 void
 kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size)
 {
 
-	_kmem_unback(object, addr, size);
+	(void)_kmem_unback(object, addr, size);
 }
 
 /*
@@ -539,30 +552,14 @@ kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size)
  *	original allocation.
  */
 void
-kmem_free(struct vmem *vmem, vm_offset_t addr, vm_size_t size)
+kmem_free(vm_offset_t addr, vm_size_t size)
 {
 	struct vmem *arena;
-	int domain;
-
-#if VM_NRESERVLEVEL > 0
-	KASSERT(vmem == kernel_arena || vmem == kernel_rwx_arena,
-	    ("kmem_free: Only kernel_arena or kernel_rwx_arena are supported."));
-#else
-	KASSERT(vmem == kernel_arena,
-	    ("kmem_free: Only kernel_arena is supported."));
-#endif
 
 	size = round_page(size);
-	domain = _kmem_unback(kernel_object, addr, size);
-#if VM_NRESERVLEVEL > 0
-	if (__predict_true(vmem == kernel_arena))
-		arena = vm_dom[domain].vmd_kernel_arena;
-	else
-		arena = vm_dom[domain].vmd_kernel_rwx_arena;
-#else
-	arena = vm_dom[domain].vmd_kernel_arena;
-#endif
-	vmem_free(arena, addr, size);
+	arena = _kmem_unback(kernel_object, addr, size);
+	if (arena != NULL)
+		vmem_free(arena, addr, size);
 }
 
 /*
diff --git a/sys/vm/vm_page.h b/sys/vm/vm_page.h
index d6a4115b89be0..73d289fd8b136 100644
--- a/sys/vm/vm_page.h
+++ b/sys/vm/vm_page.h
@@ -234,7 +234,7 @@ struct vm_page {
  * 	 mappings, and such pages are also not on any PQ queue.
  *
  */
-#define	VPO_UNUSED01	0x01		/* --available-- */
+#define	VPO_KMEM_EXEC	0x01		/* kmem mapping allows execution */
 #define	VPO_SWAPSLEEP	0x02		/* waiting for swap to finish */
 #define	VPO_UNMANAGED	0x04		/* no PV management for page */
 #define	VPO_SWAPINPROG	0x08		/* swap I/O in progress on page */
diff --git a/sys/x86/iommu/busdma_dmar.c b/sys/x86/iommu/busdma_dmar.c
index 9b27878281143..40786d46621cc 100644
--- a/sys/x86/iommu/busdma_dmar.c
+++ b/sys/x86/iommu/busdma_dmar.c
@@ -479,7 +479,7 @@ dmar_bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map1)
 	} else {
 		KASSERT((map->flags & BUS_DMAMAP_DMAR_KMEM_ALLOC) != 0,
 		    ("dmar_bus_dmamem_free for non alloced map %p", map));
-		kmem_free(kernel_arena, (vm_offset_t)vaddr, tag->common.maxsize);
+		kmem_free((vm_offset_t)vaddr, tag->common.maxsize);
 		map->flags &= ~BUS_DMAMAP_DMAR_KMEM_ALLOC;
 	}
 
diff --git a/sys/x86/iommu/intel_intrmap.c b/sys/x86/iommu/intel_intrmap.c
index 6bb2355fb205c..32e11a8347e8c 100644
--- a/sys/x86/iommu/intel_intrmap.c
+++ b/sys/x86/iommu/intel_intrmap.c
@@ -374,7 +374,7 @@ dmar_fini_irt(struct dmar_unit *unit)
 		dmar_disable_ir(unit);
 		dmar_qi_invalidate_iec_glob(unit);
 		vmem_destroy(unit->irtids);
-		kmem_free(kernel_arena, (vm_offset_t)unit->irt,
-		    unit->irte_cnt * sizeof(dmar_irte_t));
+		kmem_free((vm_offset_t)unit->irt, unit->irte_cnt *
+		    sizeof(dmar_irte_t));
 	}
 }
diff --git a/sys/x86/iommu/intel_qi.c b/sys/x86/iommu/intel_qi.c
index e2c923c4b3e9d..ed72a0d8900a0 100644
--- a/sys/x86/iommu/intel_qi.c
+++ b/sys/x86/iommu/intel_qi.c
@@ -444,7 +444,7 @@ dmar_fini_qi(struct dmar_unit *unit)
 	    ("dmar%d: waiters on disabled queue", unit->unit));
 	DMAR_UNLOCK(unit);
 
-	kmem_free(kernel_arena, unit->inv_queue, unit->inv_queue_size);
+	kmem_free(unit->inv_queue, unit->inv_queue_size);
 	unit->inv_queue = 0;
 	unit->inv_queue_size = 0;
 	unit->qi_enabled = 0;
diff --git a/sys/x86/x86/busdma_bounce.c b/sys/x86/x86/busdma_bounce.c
index f124eff29bf29..1c76804a61d59 100644
--- a/sys/x86/x86/busdma_bounce.c
+++ b/sys/x86/x86/busdma_bounce.c
@@ -499,8 +499,7 @@ bounce_bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 	if ((dmat->bounce_flags & BUS_DMA_KMEM_ALLOC) == 0)
 		free_domain(vaddr, M_DEVBUF);
 	else
-		kmem_free(kernel_arena, (vm_offset_t)vaddr,
-		    dmat->common.maxsize);
+		kmem_free((vm_offset_t)vaddr, dmat->common.maxsize);
 	CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat,
 	    dmat->bounce_flags);
 }