Remove the spilling code for IBAT register and set up the first IBAT register

to cover the first 8 MB of memory such that it covers kernel .text and not
much else.  This is a first step towards W^X in the kernel for machines
with G4 and older processors.

ok mpi@

5 files changed, 46 insertions, 78 deletions

diff --git a/sys/arch/macppc/macppc/locore.S b/sys/arch/macppc/macppc/locore.S
index 49f4b291eb3..c738d339720 100644
--- a/sys/arch/macppc/macppc/locore.S
+++ b/sys/arch/macppc/macppc/locore.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: locore.S,v 1.47 2014/10/18 22:36:36 kettenis Exp $	*/
+/*	$OpenBSD: locore.S,v 1.48 2014/10/27 21:56:57 kettenis Exp $	*/
 /*	$NetBSD: locore.S,v 1.2 1996/10/16 19:33:09 ws Exp $	*/
 
 /*
@@ -417,26 +417,6 @@ nop32_4e:
 	mfcr	%r29			/* save CR */
 	mfsrr1	%r31			/* test kernel mode */
 	mfsprg	%r1,1                   /* restore SP */
-nop64_2s:
-	mtcr	%r31
-	bc	12,17,1f		/* branch if PSL_PR is set */
-	mfsrr0	%r31			/* get fault address */
-	rlwinm	%r31,%r31,7,25,28		/* get segment * 8 */
-	addis	%r31,%r31,_C_LABEL(battable)@ha
-	lwz	%r30,_C_LABEL(battable)@l(%r31)	/* get batu */
-	mtcr	%r30
-	bc	4,30,1f			/* branch if supervisor valid is false */
-	mtibatu	3,%r30
-	lwz	%r30,_C_LABEL(battable)+4@l(%r31)	/* get batl */
-	mtibatl	3,%r30
-	mtcr	%r29			/* restore CR */
-	mtsprg	1,%r1
-	GET_CPUINFO(%r1)
-	lmw	%r28,CI_DISISAVE(%r1)	/* restore r28-r31 */
-	mfsprg	%r1,1
-	rfi				/* return to trapped code */
-1:
-nop64_2e:
 	bla	s_isitrap
 _C_LABEL(isisize) =	.-_C_LABEL(isitrap)
 
@@ -1355,7 +1335,6 @@ _C_LABEL(rfi_start):
 	.globl  _C_LABEL(nop64_start)
 _C_LABEL(nop64_start):
 	.long	nop64_1s, nop64_1e
-	.long	nop64_2s, nop64_2e
 	.long	0, 0
 
 	.globl  _C_LABEL(nop32_start)
diff --git a/sys/arch/macppc/macppc/machdep.c b/sys/arch/macppc/macppc/machdep.c
index 6d5ac8fd694..69d0672e128 100644
--- a/sys/arch/macppc/macppc/machdep.c
+++ b/sys/arch/macppc/macppc/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.162 2014/09/19 17:34:05 kettenis Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.163 2014/10/27 21:56:57 kettenis Exp $	*/
 /*	$NetBSD: machdep.c,v 1.4 1996/10/16 19:33:11 ws Exp $	*/
 
 /*
@@ -195,7 +195,7 @@ initppc(startkernel, endkernel, args)
 	 * Set up initial BAT table to only map the lowest 256 MB area
 	 */
 	battable[0].batl = BATL(0x00000000, BAT_M);
-	battable[0].batu = BATU(0x00000000);
+	battable[0].batu = BATU(0x00000000, BAT_BL_256M);
 
 	/*
 	 * Now setup fixed bat registers
@@ -203,14 +203,14 @@ initppc(startkernel, endkernel, args)
 	 * Note that we still run in real mode, and the BAT
 	 * registers were cleared above.
 	 */
-	/* IBAT0 used for initial 256 MB segment */
-	ppc_mtibat0l(battable[0].batl);
-	ppc_mtibat0u(battable[0].batu);
-
-	/* DBAT0 used similar */
+	/* DBAT0 used for initial 256 MB segment */
 	ppc_mtdbat0l(battable[0].batl);
 	ppc_mtdbat0u(battable[0].batu);
 
+	/* IBAT0 only covering the kernel .text */
+	ppc_mtibat0l(battable[0].batl);
+	ppc_mtibat0u(BATU(0x00000000, BAT_BL_8M));
+
 	/*
 	 * Set up trap vectors
 	 */
@@ -281,31 +281,31 @@ initppc(startkernel, endkernel, args)
 	/* now that we know physmem size, map physical memory with BATs */
 	if (physmem > atop(0x10000000)) {
 		battable[0x1].batl = BATL(0x10000000, BAT_M);
-		battable[0x1].batu = BATU(0x10000000);
+		battable[0x1].batu = BATU(0x10000000, BAT_BL_256M);
 	}
 	if (physmem > atop(0x20000000)) {
 		battable[0x2].batl = BATL(0x20000000, BAT_M);
-		battable[0x2].batu = BATU(0x20000000);
+		battable[0x2].batu = BATU(0x20000000, BAT_BL_256M);
 	}
 	if (physmem > atop(0x30000000)) {
 		battable[0x3].batl = BATL(0x30000000, BAT_M);
-		battable[0x3].batu = BATU(0x30000000);
+		battable[0x3].batu = BATU(0x30000000, BAT_BL_256M);
 	}
 	if (physmem > atop(0x40000000)) {
 		battable[0x4].batl = BATL(0x40000000, BAT_M);
-		battable[0x4].batu = BATU(0x40000000);
+		battable[0x4].batu = BATU(0x40000000, BAT_BL_256M);
 	}
 	if (physmem > atop(0x50000000)) {
 		battable[0x5].batl = BATL(0x50000000, BAT_M);
-		battable[0x5].batu = BATU(0x50000000);
+		battable[0x5].batu = BATU(0x50000000, BAT_BL_256M);
 	}
 	if (physmem > atop(0x60000000)) {
 		battable[0x6].batl = BATL(0x60000000, BAT_M);
-		battable[0x6].batu = BATU(0x60000000);
+		battable[0x6].batu = BATU(0x60000000, BAT_BL_256M);
 	}
 	if (physmem > atop(0x70000000)) {
 		battable[0x7].batl = BATL(0x70000000, BAT_M);
-		battable[0x7].batu = BATU(0x70000000);
+		battable[0x7].batu = BATU(0x70000000, BAT_BL_256M);
 	}
 
 	/*
diff --git a/sys/arch/powerpc/include/bat.h b/sys/arch/powerpc/include/bat.h
index 0979388d76b..d2601d9a2bd 100644
--- a/sys/arch/powerpc/include/bat.h
+++ b/sys/arch/powerpc/include/bat.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bat.h,v 1.4 2001/09/01 15:49:05 drahn Exp $	*/
+/*	$OpenBSD: bat.h,v 1.5 2014/10/27 21:56:57 kettenis Exp $	*/
 
 /*
  * Copyright (C) 1995, 1996 Wolfgang Solfrank.
@@ -39,7 +39,7 @@ struct bat {
 	u_int32_t batl;
 };
 
-#define	BATU(vaddr)		(((vaddr)&0xf0000000)|0x1ffe)
+#define	BATU(vaddr,len)		(((vaddr)&0xf0000000)|(len)|0x2)
 #define	BATL(raddr,wimg)	(((raddr)&0xf0000000)|(wimg)|0x2)
 
 #define	BAT_W		0x40
@@ -47,6 +47,19 @@ struct bat {
 #define	BAT_M		0x10
 #define	BAT_G		0x08
 
+#define BAT_BL_128K     0x00000000
+#define BAT_BL_256K     0x00000004
+#define BAT_BL_512K     0x0000000c
+#define BAT_BL_1M       0x0000001c
+#define BAT_BL_2M       0x0000003c
+#define BAT_BL_4M       0x0000007c
+#define BAT_BL_8M       0x000000fc
+#define BAT_BL_16M      0x000001fc
+#define BAT_BL_32M      0x000003fc
+#define BAT_BL_64M      0x000007fc
+#define BAT_BL_128M     0x00000ffc
+#define BAT_BL_256M     0x00001ffc
+
 #ifdef	_KERNEL
 extern struct bat battable[16];
 #endif
diff --git a/sys/arch/socppc/socppc/locore.S b/sys/arch/socppc/socppc/locore.S
index bee05821cb8..603634f27f4 100644
--- a/sys/arch/socppc/socppc/locore.S
+++ b/sys/arch/socppc/socppc/locore.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: locore.S,v 1.14 2014/10/18 22:36:36 kettenis Exp $	*/
+/*	$OpenBSD: locore.S,v 1.15 2014/10/27 21:56:57 kettenis Exp $	*/
 /*	$NetBSD: locore.S,v 1.2 1996/10/16 19:33:09 ws Exp $	*/
 
 /*
@@ -436,26 +436,6 @@ nop32_4e:
 	mfcr	%r29			/* save CR */
 	mfsrr1	%r31			/* test kernel mode */
 	mfsprg	%r1,1                   /* restore SP */
-nop64_2s:
-	mtcr	%r31
-	bc	12,17,1f		/* branch if PSL_PR is set */
-	mfsrr0	%r31			/* get fault address */
-	rlwinm	%r31,%r31,7,25,28		/* get segment * 8 */
-	addis	%r31,%r31,_C_LABEL(battable)@ha
-	lwz	%r30,_C_LABEL(battable)@l(%r31)	/* get batu */
-	mtcr	%r30
-	bc	4,30,1f			/* branch if supervisor valid is false */
-	mtibatu	3,%r30
-	lwz	%r30,_C_LABEL(battable)+4@l(%r31)	/* get batl */
-	mtibatl	3,%r30
-	mtcr	%r29			/* restore CR */
-	mtsprg	1,%r1
-	GET_CPUINFO(%r1)
-	lmw	%r28,CI_DISISAVE(%r1)	/* restore r28-r31 */
-	mfsprg	%r1,1
-	rfi				/* return to trapped code */
-1:
-nop64_2e:
 	bla	s_isitrap
 _C_LABEL(isisize) =	.-_C_LABEL(isitrap)
 
@@ -1374,7 +1354,6 @@ _C_LABEL(rfi_start):
 	.globl  _C_LABEL(nop64_start)
 _C_LABEL(nop64_start):
 	.long	nop64_1s, nop64_1e
-	.long	nop64_2s, nop64_2e
 	.long	0, 0
 
 	.globl  _C_LABEL(nop32_start)
diff --git a/sys/arch/socppc/socppc/machdep.c b/sys/arch/socppc/socppc/machdep.c
index dbf893adffc..08bccc29d09 100644
--- a/sys/arch/socppc/socppc/machdep.c
+++ b/sys/arch/socppc/socppc/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.57 2014/09/19 17:34:05 kettenis Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.58 2014/10/27 21:56:57 kettenis Exp $	*/
 /*	$NetBSD: machdep.c,v 1.4 1996/10/16 19:33:11 ws Exp $	*/
 
 /*
@@ -254,11 +254,8 @@ initppc(u_int startkernel, u_int endkernel, char *args)
 	 * Set up initial BAT table to only map the lowest 256 MB area
 	 */
 	battable[0].batl = BATL(0x00000000, BAT_M);
-#if 0
-	battable[0].batu = BATU(0x00000000);
-#else
-	battable[0].batu = 0x0ffe; /* XXX only map 128MB for now */
-#endif
+	 /* XXX only map 128MB for now */
+	battable[0].batu = BATU(0x00000000, BAT_BL_128M);
 
 	/*
 	 * Now setup fixed bat registers
@@ -266,14 +263,14 @@ initppc(u_int startkernel, u_int endkernel, char *args)
 	 * Note that we still run in real mode, and the BAT
 	 * registers were cleared above.
 	 */
-	/* IBAT0 used for initial 256 MB segment */
-	ppc_mtibat0l(battable[0].batl);
-	ppc_mtibat0u(battable[0].batu);
-
-	/* DBAT0 used similar */
+	/* DBAT0 used for initial 256 MB segment */
 	ppc_mtdbat0l(battable[0].batl);
 	ppc_mtdbat0u(battable[0].batu);
 
+	/* IBAT0 only covering the kernel .text */
+	ppc_mtibat0l(battable[0].batl);
+	ppc_mtibat0u(BATU(0x00000000, BAT_BL_8M));
+
 	/*
 	 * Set up trap vectors
 	 */
@@ -330,31 +327,31 @@ initppc(u_int startkernel, u_int endkernel, char *args)
 	/* now that we know physmem size, map physical memory with BATs */
 	if (physmem > atop(0x10000000)) {
 		battable[0x1].batl = BATL(0x10000000, BAT_M);
-		battable[0x1].batu = BATU(0x10000000);
+		battable[0x1].batu = BATU(0x10000000, BAT_BL_256M);
 	}
 	if (physmem > atop(0x20000000)) {
 		battable[0x2].batl = BATL(0x20000000, BAT_M);
-		battable[0x2].batu = BATU(0x20000000);
+		battable[0x2].batu = BATU(0x20000000, BAT_BL_256M);
 	}
 	if (physmem > atop(0x30000000)) {
 		battable[0x3].batl = BATL(0x30000000, BAT_M);
-		battable[0x3].batu = BATU(0x30000000);
+		battable[0x3].batu = BATU(0x30000000, BAT_BL_256M);
 	}
 	if (physmem > atop(0x40000000)) {
 		battable[0x4].batl = BATL(0x40000000, BAT_M);
-		battable[0x4].batu = BATU(0x40000000);
+		battable[0x4].batu = BATU(0x40000000, BAT_BL_256M);
 	}
 	if (physmem > atop(0x50000000)) {
 		battable[0x5].batl = BATL(0x50000000, BAT_M);
-		battable[0x5].batu = BATU(0x50000000);
+		battable[0x5].batu = BATU(0x50000000, BAT_BL_256M);
 	}
 	if (physmem > atop(0x60000000)) {
 		battable[0x6].batl = BATL(0x60000000, BAT_M);
-		battable[0x6].batu = BATU(0x60000000);
+		battable[0x6].batu = BATU(0x60000000, BAT_BL_256M);
 	}
 	if (physmem > atop(0x70000000)) {
 		battable[0x7].batl = BATL(0x70000000, BAT_M);
-		battable[0x7].batu = BATU(0x70000000);
+		battable[0x7].batu = BATU(0x70000000, BAT_BL_256M);
 	}
 
 	/*