from netbsd:

Prevent possible race condition in ctx_alloc().
Remove some bogus casts
Make pmap_prefer() also return a preferred virtual address when there's no
associated physical page

1 files changed, 40 insertions, 28 deletions

diff --git a/sys/arch/sparc/sparc/pmap.c b/sys/arch/sparc/sparc/pmap.c
index 38c717eb532..be83605c3ab 100644
--- a/sys/arch/sparc/sparc/pmap.c
+++ b/sys/arch/sparc/sparc/pmap.c
@@ -1079,7 +1079,7 @@ ctx_alloc(pm)
 	register struct pmap *pm;
 {
 	register union ctxinfo *c;
-	register int cnum, i;
+	register int s, cnum, i, doflush;
 	register struct regmap *rp;
 	register int gap_start, gap_end;
 	register unsigned long va;
@@ -1093,10 +1093,11 @@ ctx_alloc(pm)
 	gap_start = pm->pm_gap_start;
 	gap_end = pm->pm_gap_end;
 
+	s = splpmap();
 	if ((c = ctx_freelist) != NULL) {
 		ctx_freelist = c->c_nextfree;
 		cnum = c - ctxinfo;
-		setcontext(cnum);
+		doflush = 0;
 	} else {
 		if ((ctx_kick += ctx_kickdir) >= ncontext) {
 			ctx_kick = ncontext - 1;
@@ -1114,17 +1115,20 @@ ctx_alloc(pm)
 			    cnum, c->c_pmap);
 #endif
 		c->c_pmap->pm_ctx = NULL;
-		setcontext(cnum);
-		if (vactype != VAC_NONE)
-			cache_flush_context();
+		doflush = (vactype != VAC_NONE);
 		if (gap_start < c->c_pmap->pm_gap_start)
 			gap_start = c->c_pmap->pm_gap_start;
 		if (gap_end > c->c_pmap->pm_gap_end)
 			gap_end = c->c_pmap->pm_gap_end;
 	}
+
+	setcontext(cnum);
 	c->c_pmap = pm;
 	pm->pm_ctx = c;
 	pm->pm_ctxnum = cnum;
+	splx(s);
+	if (doflush)
+		cache_flush_context();
 
 	/*
 	 * Write pmap's region (3-level MMU) or segment table into the MMU.
@@ -1408,7 +1412,7 @@ pv_unlink(pv, pm, va)
 			pv->pv_next = npv->pv_next;
 			pv->pv_pmap = npv->pv_pmap;
 			pv->pv_va = npv->pv_va;
-			free((caddr_t)npv, M_VMPVENT);
+			free(npv, M_VMPVENT);
 		} else
 			pv->pv_pmap = NULL;
 	} else {
@@ -1422,7 +1426,7 @@ pv_unlink(pv, pm, va)
 				break;
 		}
 		prev->pv_next = npv->pv_next;
-		free((caddr_t)npv, M_VMPVENT);
+		free(npv, M_VMPVENT);
 	}
 	if (pv->pv_flags & PV_NC) {
 		/*
@@ -2066,7 +2070,7 @@ pmap_destroy(pm)
 	simple_unlock(&pm->pm_lock);
 	if (count == 0) {
 		pmap_release(pm);
-		free((caddr_t)pm, M_VMPMAP);
+		free(pm, M_VMPMAP);
 	}
 }
 
@@ -2124,7 +2128,7 @@ pmap_release(pm)
 }
 #endif
 	if (pm->pm_regstore)
-		free((caddr_t)pm->pm_regstore, M_VMPMAP);
+		free(pm->pm_regstore, M_VMPMAP);
 }
 
 /*
@@ -2382,10 +2386,10 @@ pmap_rmu(pm, va, endva, vr, vs)
 			*pte = 0;
 		}
 		if ((sp->sg_npte = nleft) == 0) {
-			free((caddr_t)pte0, M_VMPMAP);
+			free(pte0, M_VMPMAP);
 			sp->sg_pte = NULL;
 			if (--rp->rg_nsegmap == 0) {
-				free((caddr_t)rp->rg_segmap, M_VMPMAP);
+				free(rp->rg_segmap, M_VMPMAP);
 				rp->rg_segmap = NULL;
 #ifdef MMU_3L
 				if (mmu_3l && rp->rg_smeg != reginval) {
@@ -2472,12 +2476,12 @@ if (pm->pm_ctx == NULL) {
 			setsegmap(vs << SGSHIFT, seginval);
 		}
 #endif
-		free((caddr_t)pte0, M_VMPMAP);
+		free(pte0, M_VMPMAP);
 		sp->sg_pte = NULL;
 		me_free(pm, pmeg);
 
 		if (--rp->rg_nsegmap == 0) {
-			free((caddr_t)rp->rg_segmap, M_VMPMAP);
+			free(rp->rg_segmap, M_VMPMAP);
 			rp->rg_segmap = NULL;
 			GAP_WIDEN(pm,vr);
 
@@ -2567,10 +2571,10 @@ pmap_page_protect(pa, prot)
 			if (nleft) {
 				sp->sg_pte[VA_VPG(va)] = 0;
 			} else {
-				free((caddr_t)sp->sg_pte, M_VMPMAP);
+				free(sp->sg_pte, M_VMPMAP);
 				sp->sg_pte = NULL;
 				if (--rp->rg_nsegmap == 0) {
-					free((caddr_t)rp->rg_segmap, M_VMPMAP);
+					free(rp->rg_segmap, M_VMPMAP);
 					rp->rg_segmap = NULL;
 					GAP_WIDEN(pm,vr);
 #ifdef MMU_3L
@@ -2646,7 +2650,7 @@ pmap_page_protect(pa, prot)
 					setsegmap(vs << SGSHIFT, seginval);
 				}
 #endif
-				free((caddr_t)sp->sg_pte, M_VMPMAP);
+				free(sp->sg_pte, M_VMPMAP);
 				sp->sg_pte = NULL;
 				me_free(pm, sp->sg_pmeg);
 
@@ -2658,7 +2662,7 @@ pmap_page_protect(pa, prot)
 						region_free(pm, rp->rg_smeg);
 					}
 #endif
-					free((caddr_t)rp->rg_segmap, M_VMPMAP);
+					free(rp->rg_segmap, M_VMPMAP);
 					rp->rg_segmap = NULL;
 					GAP_WIDEN(pm,vr);
 				}
@@ -2667,7 +2671,7 @@ pmap_page_protect(pa, prot)
 	nextpv:
 		npv = pv->pv_next;
 		if (pv != pv0)
-			free((caddr_t)pv, M_VMPVENT);
+			free(pv, M_VMPVENT);
 		if ((pv = npv) == NULL)
 			break;
 	}
@@ -3133,7 +3137,7 @@ rretry:
 		sp = (struct segmap *)malloc((u_long)size, M_VMPMAP, M_WAITOK);
 		if (rp->rg_segmap != NULL) {
 printf("pmap_enter: segment filled during sleep\n");	/* can this happen? */
-			free((caddr_t)sp, M_VMPMAP);
+			free(sp, M_VMPMAP);
 			goto rretry;
 		}
 		bzero((caddr_t)sp, size);
@@ -3153,7 +3157,7 @@ sretry:
 		pte = (int *)malloc((u_long)size, M_VMPMAP, M_WAITOK);
 		if (sp->sg_pte != NULL) {
 printf("pmap_enter: pte filled during sleep\n");	/* can this happen? */
-			free((caddr_t)pte, M_VMPMAP);
+			free(pte, M_VMPMAP);
 			goto sretry;
 		}
 #ifdef DEBUG
@@ -3626,23 +3630,31 @@ pmap_prefer(pa, va)
 	register struct pvlist	*pv;
 	register long		m, d;
 
-	if (cputyp == CPU_SUN4M)
-		/* does the sun4m have the cache alias problem? */
-		return va;
-
 	m = CACHE_ALIAS_DIST;
+	if (m == 0)		/* m=0 => no cache aliasing */
+		return (va);
+
+	if (pa == (vm_offset_t)-1) {
+		/*
+		 * Do not consider physical address. Just return
+		 * a cache aligned address.
+		 */     
+		if (VA_INHOLE(va))
+			va = MMU_HOLE_END;
+
+		/* XXX - knowledge about `exec' formats; can we get by without? */
+		va -= USRTEXT;
+		va = (va + m - 1) & ~(m - 1);
+		return (va + USRTEXT);
+	}
 
 	if ((pa & (PMAP_TNC & ~PMAP_NC)) || !managed(pa))
 		return va;
 
 	pv = pvhead(pa);
 	if (pv->pv_pmap == NULL) {
-#if 0
-		return ((va + m - 1) & ~(m - 1));
-#else
 		/* Unusable, tell caller to try another one */
 		return (vm_offset_t)-1;
-#endif
 	}
 
 	d = (long)(pv->pv_va & (m - 1)) - (long)(va & (m - 1));