Like r310481 for i386, move the objects used to create temporary

mappings for armv6 pmap zero and copy operations to the MD PCPU region.
Change sysmap initialization to only allocate KVA pages for CPUs that
are actually present.

While here, collapse CMAP3 into CMAP2 (their use was mutually exclusive
anyway) and "recover" some space in PCPU padding that has always been
available due to 64-byte cacheline padding.

Reviewed by:	skra
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D9172

2 files changed, 146 insertions, 118 deletions

diff --git a/sys/arm/arm/pmap-v6.c b/sys/arm/arm/pmap-v6.c
index 805a09d5f130..a8de0e51d6ea 100644
--- a/sys/arm/arm/pmap-v6.c
+++ b/sys/arm/arm/pmap-v6.c
@@ -110,11 +110,6 @@ __FBSDID("$FreeBSD$");
 #include <sys/smp.h>
 #include <sys/sched.h>
 #include <sys/sysctl.h>
-#ifdef SMP
-#include <sys/smp.h>
-#else
-#include <sys/cpuset.h>
-#endif
 
 #ifdef DDB
 #include <ddb/ddb.h>
@@ -296,16 +291,6 @@ vm_paddr_t first_managed_pa;
 /*
  *  All those kernel PT submaps that BSD is so fond of
  */
-struct sysmaps {
-	struct	mtx lock;
-	pt2_entry_t *CMAP1;
-	pt2_entry_t *CMAP2;
-	pt2_entry_t *CMAP3;
-	caddr_t	CADDR1;
-	caddr_t	CADDR2;
-	caddr_t	CADDR3;
-};
-static struct sysmaps sysmaps_pcpu[MAXCPU];
 caddr_t _tmppt = 0;
 
 struct msgbuf *msgbufp = NULL; /* XXX move it to machdep.c */
@@ -1134,8 +1119,7 @@ void
 pmap_bootstrap(vm_offset_t firstaddr)
 {
 	pt2_entry_t *unused __unused;
-	struct sysmaps *sysmaps;
-	u_int i;
+	struct pcpu *pc;
 
 	/*
 	 * Initialize the kernel pmap (which is statically allocated).
@@ -1174,15 +1158,13 @@ pmap_bootstrap(vm_offset_t firstaddr)
 
 	/*
 	 * Local CMAP1/CMAP2 are used for zeroing and copying pages.
-	 * Local CMAP3 is used for data cache cleaning.
+	 * Local CMAP2 is also used for data cache cleaning.
 	 */
-	for (i = 0; i < MAXCPU; i++) {
-		sysmaps = &sysmaps_pcpu[i];
-		mtx_init(&sysmaps->lock, "SYSMAPS", NULL, MTX_DEF);
-		SYSMAP(caddr_t, sysmaps->CMAP1, sysmaps->CADDR1, 1);
-		SYSMAP(caddr_t, sysmaps->CMAP2, sysmaps->CADDR2, 1);
-		SYSMAP(caddr_t, sysmaps->CMAP3, sysmaps->CADDR3, 1);
-	}
+	pc = pcpu_find(curcpu);
+	mtx_init(&pc->pc_cmap_lock, "SYSMAPS", NULL, MTX_DEF);
+	SYSMAP(caddr_t, pc->pc_cmap1_pte2p, pc->pc_cmap1_addr, 1);
+	SYSMAP(caddr_t, pc->pc_cmap2_pte2p, pc->pc_cmap2_addr, 1);
+	SYSMAP(vm_offset_t, unused, pc->pc_qmap_addr, 1);
 
 	/*
 	 * Crashdump maps.
@@ -1215,19 +1197,32 @@ pmap_bootstrap(vm_offset_t firstaddr)
 }
 
 static void
-pmap_init_qpages(void)
+pmap_init_reserved_pages(void)
 {
 	struct pcpu *pc;
+	vm_offset_t pages;
 	int i;
 
 	CPU_FOREACH(i) {
 		pc = pcpu_find(i);
-		pc->pc_qmap_addr = kva_alloc(PAGE_SIZE);
-		if (pc->pc_qmap_addr == 0)
+		/*
+		 * Skip if the mapping has already been initialized,
+		 * i.e. this is the BSP.
+		 */
+		if (pc->pc_cmap1_addr != 0)
+			continue;
+		mtx_init(&pc->pc_cmap_lock, "SYSMAPS", NULL, MTX_DEF);
+		pages = kva_alloc(PAGE_SIZE * 3);
+		if (pages == 0)
 			panic("%s: unable to allocate KVA", __func__);
+		pc->pc_cmap1_pte2p = pt2map_entry(pages);
+		pc->pc_cmap2_pte2p = pt2map_entry(pages + PAGE_SIZE);
+		pc->pc_cmap1_addr = (caddr_t)pages;
+		pc->pc_cmap2_addr = (caddr_t)(pages + PAGE_SIZE);
+		pc->pc_qmap_addr = pages + (PAGE_SIZE * 2);
 	}
 }
-SYSINIT(qpages_init, SI_SUB_CPU, SI_ORDER_ANY, pmap_init_qpages, NULL);
+SYSINIT(rpages_init, SI_SUB_CPU, SI_ORDER_ANY, pmap_init_reserved_pages, NULL);
 
 /*
  *  The function can already be use in second initialization stage.
@@ -1578,8 +1573,9 @@ pagezero(void *page)
 static __inline vm_paddr_t
 pmap_pt2pg_zero(vm_page_t m)
 {
+	pt2_entry_t *cmap2_pte2p;
 	vm_paddr_t pa;
-	struct sysmaps *sysmaps;
+	struct pcpu *pc;
 
 	pa = VM_PAGE_TO_PHYS(m);
 
@@ -1588,20 +1584,27 @@ pmap_pt2pg_zero(vm_page_t m)
 	 *      to sync it even if the sync is only DSB.
 	 */
 	sched_pin();
-	sysmaps = &sysmaps_pcpu[PCPU_GET(cpuid)];
-	mtx_lock(&sysmaps->lock);
-	if (pte2_load(sysmaps->CMAP2) != 0)
+	pc = pcpu_find(curcpu);
+	cmap2_pte2p = pc->pc_cmap2_pte2p;
+	mtx_lock(&pc->pc_cmap_lock);
+	if (pte2_load(cmap2_pte2p) != 0)
 		panic("%s: CMAP2 busy", __func__);
-	pte2_store(sysmaps->CMAP2, PTE2_KERN_NG(pa, PTE2_AP_KRW,
+	pte2_store(cmap2_pte2p, PTE2_KERN_NG(pa, PTE2_AP_KRW,
 	    vm_page_pte2_attr(m)));
 	/*  Even VM_ALLOC_ZERO request is only advisory. */
 	if ((m->flags & PG_ZERO) == 0)
-		pagezero(sysmaps->CADDR2);
-	pte2_sync_range((pt2_entry_t *)sysmaps->CADDR2, PAGE_SIZE);
-	pte2_clear(sysmaps->CMAP2);
-	tlb_flush((vm_offset_t)sysmaps->CADDR2);
+		pagezero(pc->pc_cmap2_addr);
+	pte2_sync_range((pt2_entry_t *)pc->pc_cmap2_addr, PAGE_SIZE);
+	pte2_clear(cmap2_pte2p);
+	tlb_flush((vm_offset_t)pc->pc_cmap2_addr);
+
+	/*
+	 * Unpin the thread before releasing the lock.  Otherwise the thread
+	 * could be rescheduled while still bound to the current CPU, only
+	 * to unpin itself immediately upon resuming execution.
+	 */
 	sched_unpin();
-	mtx_unlock(&sysmaps->lock);
+	mtx_unlock(&pc->pc_cmap_lock);
 
 	return (pa);
 }
@@ -5628,9 +5631,10 @@ small_mappings:
 void
 pmap_page_set_memattr(vm_page_t m, vm_memattr_t ma)
 {
-	struct sysmaps *sysmaps;
+	pt2_entry_t *cmap2_pte2p;
 	vm_memattr_t oma;
 	vm_paddr_t pa;
+	struct pcpu *pc;
 
 	oma = m->md.pat_mode;
 	m->md.pat_mode = ma;
@@ -5657,17 +5661,18 @@ pmap_page_set_memattr(vm_page_t m, vm_memattr_t ma)
 	if (ma != oma) {
 		pa = VM_PAGE_TO_PHYS(m);
 		sched_pin();
-		sysmaps = &sysmaps_pcpu[PCPU_GET(cpuid)];
-		mtx_lock(&sysmaps->lock);
-		if (*sysmaps->CMAP2)
+		pc = pcpu_find(curcpu);
+		cmap2_pte2p = pc->pc_cmap2_pte2p;
+		mtx_lock(&pc->pc_cmap_lock);
+		if (pte2_load(cmap2_pte2p) != 0)
 			panic("%s: CMAP2 busy", __func__);
-		pte2_store(sysmaps->CMAP2, PTE2_KERN_NG(pa, PTE2_AP_KRW,
+		pte2_store(cmap2_pte2p, PTE2_KERN_NG(pa, PTE2_AP_KRW,
 		    vm_memattr_to_pte2(ma)));
-		dcache_wbinv_poc((vm_offset_t)sysmaps->CADDR2, pa, PAGE_SIZE);
-		pte2_clear(sysmaps->CMAP2);
-		tlb_flush((vm_offset_t)sysmaps->CADDR2);
+		dcache_wbinv_poc((vm_offset_t)pc->pc_cmap2_addr, pa, PAGE_SIZE);
+		pte2_clear(cmap2_pte2p);
+		tlb_flush((vm_offset_t)pc->pc_cmap2_addr);
 		sched_unpin();
-		mtx_unlock(&sysmaps->lock);
+		mtx_unlock(&pc->pc_cmap_lock);
 	}
 }
 
@@ -5745,20 +5750,22 @@ pmap_page_exists_quick(pmap_t pmap, vm_page_t m)
 void
 pmap_zero_page(vm_page_t m)
 {
-	struct sysmaps *sysmaps;
+	pt2_entry_t *cmap2_pte2p;
+	struct pcpu *pc;
 
 	sched_pin();
-	sysmaps = &sysmaps_pcpu[PCPU_GET(cpuid)];
-	mtx_lock(&sysmaps->lock);
-	if (pte2_load(sysmaps->CMAP2) != 0)
+	pc = pcpu_find(curcpu);
+	cmap2_pte2p = pc->pc_cmap2_pte2p;
+	mtx_lock(&pc->pc_cmap_lock);
+	if (pte2_load(cmap2_pte2p) != 0)
 		panic("%s: CMAP2 busy", __func__);
-	pte2_store(sysmaps->CMAP2, PTE2_KERN_NG(VM_PAGE_TO_PHYS(m), PTE2_AP_KRW,
+	pte2_store(cmap2_pte2p, PTE2_KERN_NG(VM_PAGE_TO_PHYS(m), PTE2_AP_KRW,
 	    vm_page_pte2_attr(m)));
-	pagezero(sysmaps->CADDR2);
-	pte2_clear(sysmaps->CMAP2);
-	tlb_flush((vm_offset_t)sysmaps->CADDR2);
+	pagezero(pc->pc_cmap2_addr);
+	pte2_clear(cmap2_pte2p);
+	tlb_flush((vm_offset_t)pc->pc_cmap2_addr);
 	sched_unpin();
-	mtx_unlock(&sysmaps->lock);
+	mtx_unlock(&pc->pc_cmap_lock);
 }
 
 /*
@@ -5770,23 +5777,25 @@ pmap_zero_page(vm_page_t m)
 void
 pmap_zero_page_area(vm_page_t m, int off, int size)
 {
-	struct sysmaps *sysmaps;
+	pt2_entry_t *cmap2_pte2p;
+	struct pcpu *pc;
 
 	sched_pin();
-	sysmaps = &sysmaps_pcpu[PCPU_GET(cpuid)];
-	mtx_lock(&sysmaps->lock);
-	if (pte2_load(sysmaps->CMAP2) != 0)
+	pc = pcpu_find(curcpu);
+	cmap2_pte2p = pc->pc_cmap2_pte2p;
+	mtx_lock(&pc->pc_cmap_lock);
+	if (pte2_load(cmap2_pte2p) != 0)
 		panic("%s: CMAP2 busy", __func__);
-	pte2_store(sysmaps->CMAP2, PTE2_KERN_NG(VM_PAGE_TO_PHYS(m), PTE2_AP_KRW,
+	pte2_store(cmap2_pte2p, PTE2_KERN_NG(VM_PAGE_TO_PHYS(m), PTE2_AP_KRW,
 	    vm_page_pte2_attr(m)));
 	if (off == 0 && size == PAGE_SIZE)
-		pagezero(sysmaps->CADDR2);
+		pagezero(pc->pc_cmap2_addr);
 	else
-		bzero(sysmaps->CADDR2 + off, size);
-	pte2_clear(sysmaps->CMAP2);
-	tlb_flush((vm_offset_t)sysmaps->CADDR2);
+		bzero(pc->pc_cmap2_addr + off, size);
+	pte2_clear(cmap2_pte2p);
+	tlb_flush((vm_offset_t)pc->pc_cmap2_addr);
 	sched_unpin();
-	mtx_unlock(&sysmaps->lock);
+	mtx_unlock(&pc->pc_cmap_lock);
 }
 
 /*
@@ -5798,26 +5807,29 @@ pmap_zero_page_area(vm_page_t m, int off, int size)
 void
 pmap_copy_page(vm_page_t src, vm_page_t dst)
 {
-	struct sysmaps *sysmaps;
+	pt2_entry_t *cmap1_pte2p, *cmap2_pte2p;
+	struct pcpu *pc;
 
 	sched_pin();
-	sysmaps = &sysmaps_pcpu[PCPU_GET(cpuid)];
-	mtx_lock(&sysmaps->lock);
-	if (pte2_load(sysmaps->CMAP1) != 0)
+	pc = pcpu_find(curcpu);
+	cmap1_pte2p = pc->pc_cmap1_pte2p;
+	cmap2_pte2p = pc->pc_cmap2_pte2p;
+	mtx_lock(&pc->pc_cmap_lock);
+	if (pte2_load(cmap1_pte2p) != 0)
 		panic("%s: CMAP1 busy", __func__);
-	if (pte2_load(sysmaps->CMAP2) != 0)
+	if (pte2_load(cmap2_pte2p) != 0)
 		panic("%s: CMAP2 busy", __func__);
-	pte2_store(sysmaps->CMAP1, PTE2_KERN_NG(VM_PAGE_TO_PHYS(src),
+	pte2_store(cmap1_pte2p, PTE2_KERN_NG(VM_PAGE_TO_PHYS(src),
 	    PTE2_AP_KR | PTE2_NM, vm_page_pte2_attr(src)));
-	pte2_store(sysmaps->CMAP2, PTE2_KERN_NG(VM_PAGE_TO_PHYS(dst),
+	pte2_store(cmap2_pte2p, PTE2_KERN_NG(VM_PAGE_TO_PHYS(dst),
 	    PTE2_AP_KRW, vm_page_pte2_attr(dst)));
-	bcopy(sysmaps->CADDR1, sysmaps->CADDR2, PAGE_SIZE);
-	pte2_clear(sysmaps->CMAP1);
-	tlb_flush((vm_offset_t)sysmaps->CADDR1);
-	pte2_clear(sysmaps->CMAP2);
-	tlb_flush((vm_offset_t)sysmaps->CADDR2);
+	bcopy(pc->pc_cmap1_addr, pc->pc_cmap2_addr, PAGE_SIZE);
+	pte2_clear(cmap1_pte2p);
+	tlb_flush((vm_offset_t)pc->pc_cmap1_addr);
+	pte2_clear(cmap2_pte2p);
+	tlb_flush((vm_offset_t)pc->pc_cmap2_addr);
 	sched_unpin();
-	mtx_unlock(&sysmaps->lock);
+	mtx_unlock(&pc->pc_cmap_lock);
 }
 
 int unmapped_buf_allowed = 1;
@@ -5826,18 +5838,21 @@ void
 pmap_copy_pages(vm_page_t ma[], vm_offset_t a_offset, vm_page_t mb[],
     vm_offset_t b_offset, int xfersize)
 {
-	struct sysmaps *sysmaps;
+	pt2_entry_t *cmap1_pte2p, *cmap2_pte2p;
 	vm_page_t a_pg, b_pg;
 	char *a_cp, *b_cp;
 	vm_offset_t a_pg_offset, b_pg_offset;
+	struct pcpu *pc;
 	int cnt;
 
 	sched_pin();
-	sysmaps = &sysmaps_pcpu[PCPU_GET(cpuid)];
-	mtx_lock(&sysmaps->lock);
-	if (*sysmaps->CMAP1 != 0)
+	pc = pcpu_find(curcpu);
+	cmap1_pte2p = pc->pc_cmap1_pte2p;
+	cmap2_pte2p = pc->pc_cmap2_pte2p;
+	mtx_lock(&pc->pc_cmap_lock);
+	if (pte2_load(cmap1_pte2p) != 0)
 		panic("pmap_copy_pages: CMAP1 busy");
-	if (*sysmaps->CMAP2 != 0)
+	if (pte2_load(cmap2_pte2p) != 0)
 		panic("pmap_copy_pages: CMAP2 busy");
 	while (xfersize > 0) {
 		a_pg = ma[a_offset >> PAGE_SHIFT];
@@ -5846,25 +5861,25 @@ pmap_copy_pages(vm_page_t ma[], vm_offset_t a_offset, vm_page_t mb[],
 		b_pg = mb[b_offset >> PAGE_SHIFT];
 		b_pg_offset = b_offset & PAGE_MASK;
 		cnt = min(cnt, PAGE_SIZE - b_pg_offset);
-		pte2_store(sysmaps->CMAP1, PTE2_KERN_NG(VM_PAGE_TO_PHYS(a_pg),
+		pte2_store(cmap1_pte2p, PTE2_KERN_NG(VM_PAGE_TO_PHYS(a_pg),
 		    PTE2_AP_KR | PTE2_NM, vm_page_pte2_attr(a_pg)));
-		tlb_flush_local((vm_offset_t)sysmaps->CADDR1);
-		pte2_store(sysmaps->CMAP2, PTE2_KERN_NG(VM_PAGE_TO_PHYS(b_pg),
+		tlb_flush_local((vm_offset_t)pc->pc_cmap1_addr);
+		pte2_store(cmap2_pte2p, PTE2_KERN_NG(VM_PAGE_TO_PHYS(b_pg),
 		    PTE2_AP_KRW, vm_page_pte2_attr(b_pg)));
-		tlb_flush_local((vm_offset_t)sysmaps->CADDR2);
-		a_cp = sysmaps->CADDR1 + a_pg_offset;
-		b_cp = sysmaps->CADDR2 + b_pg_offset;
+		tlb_flush_local((vm_offset_t)pc->pc_cmap2_addr);
+		a_cp = pc->pc_cmap1_addr + a_pg_offset;
+		b_cp = pc->pc_cmap2_addr + b_pg_offset;
 		bcopy(a_cp, b_cp, cnt);
 		a_offset += cnt;
 		b_offset += cnt;
 		xfersize -= cnt;
 	}
-	pte2_clear(sysmaps->CMAP1);
-	tlb_flush((vm_offset_t)sysmaps->CADDR1);
-	pte2_clear(sysmaps->CMAP2);
-	tlb_flush((vm_offset_t)sysmaps->CADDR2);
+	pte2_clear(cmap1_pte2p);
+	tlb_flush((vm_offset_t)pc->pc_cmap1_addr);
+	pte2_clear(cmap2_pte2p);
+	tlb_flush((vm_offset_t)pc->pc_cmap2_addr);
 	sched_unpin();
-	mtx_unlock(&sysmaps->lock);
+	mtx_unlock(&pc->pc_cmap_lock);
 }
 
 vm_offset_t
@@ -6190,22 +6205,24 @@ pmap_set_pcb_pagedir(pmap_t pmap, struct pcb *pcb)
 static void
 pmap_dcache_wb_pou(vm_paddr_t pa, vm_size_t size, uint32_t attr)
 {
-	struct sysmaps *sysmaps;
+	pt2_entry_t *cmap2_pte2p;
+	struct pcpu *pc;
 
 	KASSERT(((pa & PAGE_MASK) + size) <= PAGE_SIZE,
 	    ("%s: not on single page", __func__));
 
 	sched_pin();
-	sysmaps = &sysmaps_pcpu[PCPU_GET(cpuid)];
-	mtx_lock(&sysmaps->lock);
-	if (*sysmaps->CMAP3)
-		panic("%s: CMAP3 busy", __func__);
-	pte2_store(sysmaps->CMAP3, PTE2_KERN_NG(pa, PTE2_AP_KRW, attr));
-	dcache_wb_pou((vm_offset_t)sysmaps->CADDR3 + (pa & PAGE_MASK), size);
-	pte2_clear(sysmaps->CMAP3);
-	tlb_flush((vm_offset_t)sysmaps->CADDR3);
+	pc = pcpu_find(curcpu);
+	cmap2_pte2p = pc->pc_cmap2_pte2p;
+	mtx_lock(&pc->pc_cmap_lock);
+	if (pte2_load(cmap2_pte2p) != 0)
+		panic("%s: CMAP2 busy", __func__);
+	pte2_store(cmap2_pte2p, PTE2_KERN_NG(pa, PTE2_AP_KRW, attr));
+	dcache_wb_pou((vm_offset_t)pc->pc_cmap2_addr + (pa & PAGE_MASK), size);
+	pte2_clear(cmap2_pte2p);
+	tlb_flush((vm_offset_t)pc->pc_cmap2_addr);
 	sched_unpin();
-	mtx_unlock(&sysmaps->lock);
+	mtx_unlock(&pc->pc_cmap_lock);
 }
 
 /*
@@ -6455,25 +6472,27 @@ pmap_fault(pmap_t pmap, vm_offset_t far, uint32_t fsr, int idx, bool usermode)
 static void
 pmap_zero_page_check(vm_page_t m)
 {
+	pt2_entry_t *cmap2_pte2p;
 	uint32_t *p, *end;
-	struct sysmaps *sysmaps;
+	struct pcpu *pc;
 
 	sched_pin();
-	sysmaps = &sysmaps_pcpu[PCPU_GET(cpuid)];
-	mtx_lock(&sysmaps->lock);
-	if (pte2_load(sysmaps->CMAP2) != 0)
+	pc = pcpu_find(curcpu);
+	cmap2_pte2p = pc->pc_cmap2_pte2p;
+	mtx_lock(&pc->pc_cmap_lock);
+	if (pte2_load(cmap2_pte2p) != 0)
 		panic("%s: CMAP2 busy", __func__);
-	pte2_store(sysmaps->CMAP2, PTE2_KERN_NG(VM_PAGE_TO_PHYS(m), PTE2_AP_KRW,
+	pte2_store(cmap2_pte2p, PTE2_KERN_NG(VM_PAGE_TO_PHYS(m), PTE2_AP_KRW,
 	    vm_page_pte2_attr(m)));
-	end = (uint32_t*)(sysmaps->CADDR2 + PAGE_SIZE);
-	for (p = (uint32_t*)sysmaps->CADDR2; p < end; p++)
+	end = (uint32_t*)(pc->pc_cmap2_addr + PAGE_SIZE);
+	for (p = (uint32_t*)pc->pc_cmap2_addr; p < end; p++)
 		if (*p != 0)
 			panic("%s: page %p not zero, va: %p", __func__, m,
-			    sysmaps->CADDR2);
-	pte2_clear(sysmaps->CMAP2);
-	tlb_flush((vm_offset_t)sysmaps->CADDR2);
+			    pc->pc_cmap2_addr);
+	pte2_clear(cmap2_pte2p);
+	tlb_flush((vm_offset_t)pc->pc_cmap2_addr);
 	sched_unpin();
-	mtx_unlock(&sysmaps->lock);
+	mtx_unlock(&pc->pc_cmap_lock);
 }
 
 int
diff --git a/sys/arm/include/pcpu.h b/sys/arm/include/pcpu.h
index 3cc258188ff8..d02ccc8f546c 100644
--- a/sys/arm/include/pcpu.h
+++ b/sys/arm/include/pcpu.h
@@ -32,6 +32,9 @@
 
 #ifdef _KERNEL
 
+#include <sys/_lock.h>
+#include <sys/_mutex.h>
+
 #define	ALT_STACK_SIZE	128
 
 struct vmspace;
@@ -39,16 +42,22 @@ struct vmspace;
 #endif	/* _KERNEL */
 
 #if __ARM_ARCH >= 6
+
 #define PCPU_MD_FIELDS							\
 	unsigned int pc_vfpsid;						\
 	unsigned int pc_vfpmvfr0;					\
 	unsigned int pc_vfpmvfr1;					\
 	struct pmap *pc_curpmap;					\
+	struct mtx pc_cmap_lock;					\
+	void *pc_cmap1_pte2p;						\
+	void *pc_cmap2_pte2p;						\
+	caddr_t pc_cmap1_addr;						\
+	caddr_t pc_cmap2_addr;						\
 	vm_offset_t pc_qmap_addr;					\
 	void *pc_qmap_pte;						\
 	unsigned int pc_dbreg[32];					\
 	int pc_dbreg_cmd;						\
-	char __pad[1]
+	char __pad[27]
 #else
 #define PCPU_MD_FIELDS							\
 	vm_offset_t qmap_addr;						\