From d3d1eb995bab5cf6595c27de5e372eb208e8ae3d Mon Sep 17 00:00:00 2001
From: John Dyson <dyson@FreeBSD.org>
Date: Thu, 7 Aug 1997 05:15:52 +0000
Subject: [PATCH] Fix the DDB breakpoint code when using the 4MB page support.

---
 sys/amd64/amd64/db_interface.c | 23 ++++++++++++++++-------
 sys/amd64/amd64/pmap.c         | 13 ++++++++++---
 sys/i386/i386/db_interface.c   | 23 ++++++++++++++++-------
 sys/i386/i386/pmap.c           | 13 ++++++++++---
 sys/i386/include/param.h       |  5 ++++-
 5 files changed, 56 insertions(+), 21 deletions(-)

diff --git a/sys/amd64/amd64/db_interface.c b/sys/amd64/amd64/db_interface.c
index 5c5bcccd003..738b647658d 100644
--- a/sys/amd64/amd64/db_interface.c
+++ b/sys/amd64/amd64/db_interface.c
@@ -23,7 +23,7 @@
  * any improvements or extensions that they make and grant Carnegie the
  * rights to redistribute these changes.
  *
- *	$Id: db_interface.c,v 1.34 1997/07/18 21:27:52 fsmp Exp $
+ *	$Id: db_interface.c,v 1.35 1997/07/20 08:37:17 bde Exp $
  */
 
 /*
@@ -254,14 +254,23 @@ db_write_bytes(addr, size, data)
 	    ptep0 = pmap_pte(kernel_pmap, addr);
 	    oldmap0 = *ptep0;
 	    *ptep0 |= PG_RW;
+	    if ((*ptep0 & PG_PS) == 0) {
 
-	    addr1 = trunc_page(addr + size - 1);
+	    	addr1 = trunc_page(addr + size - 1);
 
-	    /* Map another page if the data crosses a page boundary. */
-	    if (trunc_page(addr) != addr1) {
-		ptep1 = pmap_pte(kernel_pmap, addr1);
-		oldmap1 = *ptep1;
-		*ptep1 |= PG_RW;
+	    	/* Map another page if the data crosses a page boundary. */
+	    	if (trunc_page(addr) != addr1) {
+		    ptep1 = pmap_pte(kernel_pmap, addr1);
+		    oldmap1 = *ptep1;
+		    *ptep1 |= PG_RW;
+	    	}
+	    } else {
+		addr1 = trunc_4mpage(addr + size - 1);
+		if (trunc_4mpage(addr) != addr1) {
+		    ptep1 = pmap_pte(kernel_pmap, addr1);
+		    oldmap1 = *ptep1;
+		    *ptep1 |= PG_RW;
+		}
 	    }
 
 	    invltlb();
diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c
index 315b5c19f16..1fee006c831 100644
--- a/sys/amd64/amd64/pmap.c
+++ b/sys/amd64/amd64/pmap.c
@@ -39,7 +39,7 @@
  * SUCH DAMAGE.
  *
  *	from:	@(#)pmap.c	7.7 (Berkeley)	5/12/91
- *	$Id: pmap.c,v 1.156 1997/08/05 22:24:08 dyson Exp $
+ *	$Id: pmap.c,v 1.157 1997/08/07 03:52:50 dyson Exp $
  */
 
 /*
@@ -232,8 +232,15 @@ pmap_pte(pmap, va)
 	register pmap_t pmap;
 	vm_offset_t va;
 {
-	if (pmap && *pmap_pde(pmap, va)) {
-		return get_ptbase(pmap) + i386_btop(va);
+	unsigned *pdeaddr;
+
+	if (pmap) {
+		pdeaddr = (unsigned *) pmap_pde(pmap, va);
+		if (*pdeaddr & PG_PS)
+			return pdeaddr;
+		if (*pdeaddr) {
+			return get_ptbase(pmap) + i386_btop(va);
+		}
 	}
 	return (0);
 }
diff --git a/sys/i386/i386/db_interface.c b/sys/i386/i386/db_interface.c
index 5c5bcccd003..738b647658d 100644
--- a/sys/i386/i386/db_interface.c
+++ b/sys/i386/i386/db_interface.c
@@ -23,7 +23,7 @@
  * any improvements or extensions that they make and grant Carnegie the
  * rights to redistribute these changes.
  *
- *	$Id: db_interface.c,v 1.34 1997/07/18 21:27:52 fsmp Exp $
+ *	$Id: db_interface.c,v 1.35 1997/07/20 08:37:17 bde Exp $
  */
 
 /*
@@ -254,14 +254,23 @@ db_write_bytes(addr, size, data)
 	    ptep0 = pmap_pte(kernel_pmap, addr);
 	    oldmap0 = *ptep0;
 	    *ptep0 |= PG_RW;
+	    if ((*ptep0 & PG_PS) == 0) {
 
-	    addr1 = trunc_page(addr + size - 1);
+	    	addr1 = trunc_page(addr + size - 1);
 
-	    /* Map another page if the data crosses a page boundary. */
-	    if (trunc_page(addr) != addr1) {
-		ptep1 = pmap_pte(kernel_pmap, addr1);
-		oldmap1 = *ptep1;
-		*ptep1 |= PG_RW;
+	    	/* Map another page if the data crosses a page boundary. */
+	    	if (trunc_page(addr) != addr1) {
+		    ptep1 = pmap_pte(kernel_pmap, addr1);
+		    oldmap1 = *ptep1;
+		    *ptep1 |= PG_RW;
+	    	}
+	    } else {
+		addr1 = trunc_4mpage(addr + size - 1);
+		if (trunc_4mpage(addr) != addr1) {
+		    ptep1 = pmap_pte(kernel_pmap, addr1);
+		    oldmap1 = *ptep1;
+		    *ptep1 |= PG_RW;
+		}
 	    }
 
 	    invltlb();
diff --git a/sys/i386/i386/pmap.c b/sys/i386/i386/pmap.c
index 315b5c19f16..1fee006c831 100644
--- a/sys/i386/i386/pmap.c
+++ b/sys/i386/i386/pmap.c
@@ -39,7 +39,7 @@
  * SUCH DAMAGE.
  *
  *	from:	@(#)pmap.c	7.7 (Berkeley)	5/12/91
- *	$Id: pmap.c,v 1.156 1997/08/05 22:24:08 dyson Exp $
+ *	$Id: pmap.c,v 1.157 1997/08/07 03:52:50 dyson Exp $
  */
 
 /*
@@ -232,8 +232,15 @@ pmap_pte(pmap, va)
 	register pmap_t pmap;
 	vm_offset_t va;
 {
-	if (pmap && *pmap_pde(pmap, va)) {
-		return get_ptbase(pmap) + i386_btop(va);
+	unsigned *pdeaddr;
+
+	if (pmap) {
+		pdeaddr = (unsigned *) pmap_pde(pmap, va);
+		if (*pdeaddr & PG_PS)
+			return pdeaddr;
+		if (*pdeaddr) {
+			return get_ptbase(pmap) + i386_btop(va);
+		}
 	}
 	return (0);
 }
diff --git a/sys/i386/include/param.h b/sys/i386/include/param.h
index bb3a70063cf..1015164559b 100644
--- a/sys/i386/include/param.h
+++ b/sys/i386/include/param.h
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)param.h	5.8 (Berkeley) 6/28/91
- *	$Id: param.h,v 1.30 1997/07/24 23:48:51 fsmp Exp $
+ *	$Id: param.h,v 1.31 1997/08/04 19:14:47 fsmp Exp $
  */
 
 #ifndef _MACHINE_PARAM_H_
@@ -64,6 +64,7 @@
 #define NPDEPG		(PAGE_SIZE/(sizeof (pd_entry_t)))
 #define PDRSHIFT	22		/* LOG2(NBPDR) */
 #define NBPDR		(1<<PDRSHIFT)	/* bytes/page dir */
+#define PDRMASK		(NBPDR-1)
 
 #define DEV_BSHIFT	9		/* log2(DEV_BSIZE) */
 #define DEV_BSIZE	(1<<DEV_BSHIFT)
@@ -121,6 +122,8 @@
  */
 #define trunc_page(x)		((unsigned)(x) & ~PAGE_MASK)
 #define round_page(x)		((((unsigned)(x)) + PAGE_MASK) & ~PAGE_MASK)
+#define trunc_4mpage(x)		((unsigned)(x) & ~PDRMASK)
+#define round_4mpage(x)		((((unsigned)(x)) + PDRMASK) & ~PDRMASK)
 
 #define atop(x)			((unsigned)(x) >> PAGE_SHIFT)
 #define ptoa(x)			((unsigned)(x) << PAGE_SHIFT)