Use per-pmap lock to protect userland SLB handling.

3 files changed, 40 insertions, 23 deletions

diff --git a/sys/arch/powerpc64/include/pmap.h b/sys/arch/powerpc64/include/pmap.h
index aea50f9562a..50ff0464e9c 100644
--- a/sys/arch/powerpc64/include/pmap.h
+++ b/sys/arch/powerpc64/include/pmap.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pmap.h,v 1.12 2020/07/21 21:01:34 kettenis Exp $	*/
+/*	$OpenBSD: pmap.h,v 1.13 2020/07/23 15:09:09 kettenis Exp $	*/
 
 /*
  * Copyright (c) 2020 Mark Kettenis <kettenis@openbsd.org>
@@ -68,9 +68,7 @@ extern struct pmap kernel_pmap_store;
 void	pmap_bootstrap(void);
 void	pmap_bootstrap_cpu(void);
 
-struct slb_desc *pmap_slbd_lookup(pmap_t, vaddr_t);
-void	pmap_slbd_cache(pmap_t, struct slb_desc *);
-
+int	pmap_slbd_fault(pmap_t, vaddr_t);
 int	pmap_set_user_slb(pmap_t, vaddr_t, vaddr_t *, vsize_t *);
 void	pmap_unset_user_slb(void);
 
diff --git a/sys/arch/powerpc64/powerpc64/pmap.c b/sys/arch/powerpc64/powerpc64/pmap.c
index 8c167f1f3cf..9a588def095 100644
--- a/sys/arch/powerpc64/powerpc64/pmap.c
+++ b/sys/arch/powerpc64/powerpc64/pmap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pmap.c,v 1.35 2020/07/22 20:39:02 kettenis Exp $ */
+/*	$OpenBSD: pmap.c,v 1.36 2020/07/23 15:09:09 kettenis Exp $ */
 
 /*
  * Copyright (c) 2015 Martin Pieuchot
@@ -320,6 +320,8 @@ pmap_slbd_lookup(pmap_t pm, vaddr_t va)
 	uint64_t esid = va >> ADDR_ESID_SHIFT;
 	struct slb_desc *slbd;
 
+	PMAP_VP_ASSERT_LOCKED(pm);
+
 	LIST_FOREACH(slbd, &pm->pm_slbd, slbd_list) {
 		if (slbd->slbd_esid == esid)
 			return slbd;
@@ -334,6 +336,8 @@ pmap_slbd_cache(pmap_t pm, struct slb_desc *slbd)
 	uint64_t slbe, slbv;
 	int idx;
 
+	PMAP_VP_ASSERT_LOCKED(pm);
+
 	for (idx = 0; idx < nitems(pm->pm_slb); idx++) {
 		if (pm->pm_slb[idx].slb_slbe == 0)
 			break;
@@ -348,6 +352,23 @@ pmap_slbd_cache(pmap_t pm, struct slb_desc *slbd)
 	pm->pm_slb[idx].slb_slbv = slbv;
 }
 
+int
+pmap_slbd_fault(pmap_t pm, vaddr_t va)
+{
+	struct slb_desc *slbd;
+
+	PMAP_VP_LOCK(pm);
+	slbd = pmap_slbd_lookup(pm, va);
+	if (slbd) {
+		pmap_slbd_cache(pm, slbd);
+		PMAP_VP_UNLOCK(pm);
+		return 0;
+	}
+	PMAP_VP_UNLOCK(pm);
+
+	return EFAULT;
+}
+
 u_int pmap_vsid;
 
 struct slb_desc *
@@ -357,6 +378,7 @@ pmap_slbd_alloc(pmap_t pm, vaddr_t va)
 	struct slb_desc *slbd;
 
 	KASSERT(pm != pmap_kernel());
+	PMAP_VP_ASSERT_LOCKED(pm);
 
 	slbd = pool_get(&pmap_slbd_pool, PR_NOWAIT | PR_ZERO);
 	if (slbd == NULL)
@@ -379,15 +401,21 @@ pmap_set_user_slb(pmap_t pm, vaddr_t va, vaddr_t *kva, vsize_t *len)
 	struct cpu_info *ci = curcpu();
 	struct slb_desc *slbd;
 	uint64_t slbe, slbv;
+	uint64_t vsid;
 
 	KASSERT(pm != pmap_kernel());
 
+	PMAP_VP_LOCK(pm);
 	slbd = pmap_slbd_lookup(pm, va);
 	if (slbd == NULL) {
 		slbd = pmap_slbd_alloc(pm, va);
-		if (slbd == NULL)
+		if (slbd == NULL) {
+			PMAP_VP_UNLOCK(pm);
 			return EFAULT;
+		}
 	}
+	vsid = slbd->slbd_vsid;
+	PMAP_VP_UNLOCK(pm);
 
 	/*
 	 * We might get here while another process is sleeping while
@@ -401,7 +429,7 @@ pmap_set_user_slb(pmap_t pm, vaddr_t va, vaddr_t *kva, vsize_t *len)
 	}
 
 	slbe = (USER_ESID << SLBE_ESID_SHIFT) | SLBE_VALID | 31;
-	slbv = slbd->slbd_vsid << SLBV_VSID_SHIFT;
+	slbv = vsid << SLBV_VSID_SHIFT;
 
 	ci->ci_kernel_slb[31].slb_slbe = slbe;
 	ci->ci_kernel_slb[31].slb_slbv = slbv;
@@ -1313,7 +1341,9 @@ pmap_extract(pmap_t pm, vaddr_t va, paddr_t *pa)
 		return 1;
 	}
 
+	PMAP_VP_LOCK(pm);
 	vsid = pmap_va2vsid(pm, va);
+	PMAP_VP_UNLOCK(pm);
 	if (vsid == 0)
 		return 0;
 
diff --git a/sys/arch/powerpc64/powerpc64/trap.c b/sys/arch/powerpc64/powerpc64/trap.c
index ae540fd2281..4cda5ae9b2e 100644
--- a/sys/arch/powerpc64/powerpc64/trap.c
+++ b/sys/arch/powerpc64/powerpc64/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.32 2020/07/23 09:49:33 kettenis Exp $	*/
+/*	$OpenBSD: trap.c,v 1.33 2020/07/23 15:09:09 kettenis Exp $	*/
 
 /*
  * Copyright (c) 2020 Mark Kettenis <kettenis@openbsd.org>
@@ -48,7 +48,6 @@ trap(struct trapframe *frame)
 	int type = frame->exc;
 	union sigval sv;
 	struct vm_map *map;
-	struct slb_desc *slbd;
 	pmap_t pm;
 	vaddr_t va;
 	int ftype;
@@ -168,14 +167,9 @@ trap(struct trapframe *frame)
 
 	case EXC_DSE|EXC_USER:
 		pm = p->p_vmspace->vm_map.pmap;
-		KERNEL_LOCK();
-		slbd = pmap_slbd_lookup(pm, frame->dar);
-		if (slbd) {
-			pmap_slbd_cache(pm, slbd);
-			KERNEL_UNLOCK();
+		error = pmap_slbd_fault(pm, frame->dar);
+		if (error == 0)
 			break;
-		}
-		KERNEL_UNLOCK();
 		frame->dsisr = 0;
 		/* FALLTHROUGH */
 
@@ -218,14 +212,9 @@ trap(struct trapframe *frame)
 
 	case EXC_ISE|EXC_USER:
 		pm = p->p_vmspace->vm_map.pmap;
-		KERNEL_LOCK();
-		slbd = pmap_slbd_lookup(pm, frame->srr0);
-		if (slbd) {
-			pmap_slbd_cache(pm, slbd);
-			KERNEL_UNLOCK();
+		error = pmap_slbd_fault(pm, frame->srr0);
+		if (error == 0)
 			break;
-		}
-		KERNEL_UNLOCK();
 		/* FALLTHROUGH */
 
 	case EXC_ISI|EXC_USER: