From 5ce17b18e16177dd6409dabd38df5c2c9b58fc2d Mon Sep 17 00:00:00 2001
From: Eugene Surovegin <ebs@ebshome.net>
Date: Fri, 29 Jul 2005 22:59:19 -0700
Subject: [PATCH] ppc32: fix 44x early serial debug for configurations with
more than 512M of RAM
Fix 44x early serial debugging for big RAM configurations (more than 512M).
We cannot use default OpenBIOS virtual mapping, because it interferes with
pinned TLB entry.
While we are at it, move early UART mapping to TLB slot 0, so it can
survive longer during boot process (slot 1 is used by the first ioremap
call, effectively killing UART mapping if it occupies this slot). Also,
change UART TLB entry size to 4K (256M is too much for a bunch of registers
:). Squash some warnings on the way.
Tested on Ebony and Ocotea with 1G of RAM.
Thanks to Scott Coulter <scott.coulter@cyclone.com> for diagnosing this
problem.
Signed-off-by: Eugene Surovegin <ebs@ebshome.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
arch/ppc/kernel/head_44x.S | 12 ++++++------
arch/ppc/platforms/4xx/ebony.c | 6 +++++-
arch/ppc/platforms/4xx/ebony.h | 13 +++++++++++--
arch/ppc/platforms/4xx/ocotea.c | 4 ++++
arch/ppc/platforms/4xx/ocotea.h | 13 +++++++++++--
5 files changed, 37 insertions(+), 11 deletions(-)
(limited to 'arch/ppc')
diff --git a/arch/ppc/kernel/head_44x.S b/arch/ppc/kernel/head_44x.S
index 6c7ae605246..72ee8f33bde 100644
--- a/arch/ppc/kernel/head_44x.S
+++ b/arch/ppc/kernel/head_44x.S
@@ -179,14 +179,14 @@ skpinv: addi r4,r4,1 /* Increment */
4:
#ifdef CONFIG_SERIAL_TEXT_DEBUG
/*
- * Add temporary UART mapping for early debug. This
- * mapping must be identical to that used by the early
- * bootloader code since the same asm/serial.h parameters
- * are used for polled operation.
+ * Add temporary UART mapping for early debug.
+ * We can map UART registers wherever we want as long as they don't
+ * interfere with other system mappings (e.g. with pinned entries).
+ * For an example of how we handle this - see ocotea.h. --ebs
*/
/* pageid fields */
lis r3,UART0_IO_BASE@h
- ori r3,r3,PPC44x_TLB_VALID | PPC44x_TLB_256M
+ ori r3,r3,PPC44x_TLB_VALID | PPC44x_TLB_4K
/* xlat fields */
lis r4,UART0_PHYS_IO_BASE@h /* RPN depends on SoC */
@@ -196,7 +196,7 @@ skpinv: addi r4,r4,1 /* Increment */
li r5,0
ori r5,r5,(PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_I | PPC44x_TLB_G)
- li r0,1 /* TLB slot 1 */
+ li r0,0 /* TLB slot 0 */
tlbwe r3,r0,PPC44x_TLB_PAGEID /* Load the pageid fields */
tlbwe r4,r0,PPC44x_TLB_XLAT /* Load the translation fields */
diff --git a/arch/ppc/platforms/4xx/ebony.c b/arch/ppc/platforms/4xx/ebony.c
index cd11734ef7c..509e69a095f 100644
--- a/arch/ppc/platforms/4xx/ebony.c
+++ b/arch/ppc/platforms/4xx/ebony.c
@@ -7,7 +7,7 @@
* Copyright 2002-2005 MontaVista Software Inc.
*
* Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
- * Copyright (c) 2003, 2004 Zultys Technologies
+ * Copyright (c) 2003-2005 Zultys Technologies
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
@@ -50,6 +50,7 @@
#include <asm/bootinfo.h>
#include <asm/ppc4xx_pic.h>
#include <asm/ppcboot.h>
+#include <asm/tlbflush.h>
#include <syslib/gen550.h>
#include <syslib/ibm440gp_common.h>
@@ -248,6 +249,9 @@ ebony_early_serial_map(void)
#if defined(CONFIG_SERIAL_TEXT_DEBUG) || defined(CONFIG_KGDB)
/* Configure debug serial access */
gen550_init(0, &port);
+
+ /* Purge TLB entry added in head_44x.S for early serial access */
+ _tlbie(UART0_IO_BASE);
#endif
port.membase = ioremap64(PPC440GP_UART1_ADDR, 8);
diff --git a/arch/ppc/platforms/4xx/ebony.h b/arch/ppc/platforms/4xx/ebony.h
index 47c391c9174..d08faa46a0a 100644
--- a/arch/ppc/platforms/4xx/ebony.h
+++ b/arch/ppc/platforms/4xx/ebony.h
@@ -56,9 +56,18 @@
* Serial port defines
*/
-/* OpenBIOS defined UART mappings, used before early_serial_setup */
+#if defined(__BOOTER__)
+/* OpenBIOS defined UART mappings, used by bootloader shim */
#define UART0_IO_BASE 0xE0000200
#define UART1_IO_BASE 0xE0000300
+#else
+/* head_44x.S created UART mapping, used before early_serial_setup.
+ * We cannot use default OpenBIOS UART mappings because they
+ * don't work for configurations with more than 512M RAM. --ebs
+ */
+#define UART0_IO_BASE 0xF0000200
+#define UART1_IO_BASE 0xF0000300
+#endif
/* external Epson SG-615P */
#define BASE_BAUD 691200
@@ -66,7 +75,7 @@
#define STD_UART_OP(num) \
{ 0, BASE_BAUD, 0, UART##num##_INT, \
(ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST), \
- iomem_base: UART##num##_IO_BASE, \
+ iomem_base: (void*)UART##num##_IO_BASE, \
io_type: SERIAL_IO_MEM},
#define SERIAL_PORT_DFNS \
diff --git a/arch/ppc/platforms/4xx/ocotea.c b/arch/ppc/platforms/4xx/ocotea.c
index 5f82a6bc704..8fc34a34476 100644
--- a/arch/ppc/platforms/4xx/ocotea.c
+++ b/arch/ppc/platforms/4xx/ocotea.c
@@ -48,6 +48,7 @@
#include <asm/bootinfo.h>
#include <asm/ppc4xx_pic.h>
#include <asm/ppcboot.h>
+#include <asm/tlbflush.h>
#include <syslib/gen550.h>
#include <syslib/ibm440gx_common.h>
@@ -266,6 +267,9 @@ ocotea_early_serial_map(void)
#if defined(CONFIG_SERIAL_TEXT_DEBUG) || defined(CONFIG_KGDB)
/* Configure debug serial access */
gen550_init(0, &port);
+
+ /* Purge TLB entry added in head_44x.S for early serial access */
+ _tlbie(UART0_IO_BASE);
#endif
port.membase = ioremap64(PPC440GX_UART1_ADDR, 8);
diff --git a/arch/ppc/platforms/4xx/ocotea.h b/arch/ppc/platforms/4xx/ocotea.h
index 202dc825119..33251153ac5 100644
--- a/arch/ppc/platforms/4xx/ocotea.h
+++ b/arch/ppc/platforms/4xx/ocotea.h
@@ -55,15 +55,24 @@
*/
#define RS_TABLE_SIZE 2
-/* OpenBIOS defined UART mappings, used before early_serial_setup */
+#if defined(__BOOTER__)
+/* OpenBIOS defined UART mappings, used by bootloader shim */
#define UART0_IO_BASE 0xE0000200
#define UART1_IO_BASE 0xE0000300
+#else
+/* head_44x.S created UART mapping, used before early_serial_setup.
+ * We cannot use default OpenBIOS UART mappings because they
+ * don't work for configurations with more than 512M RAM. --ebs
+ */
+#define UART0_IO_BASE 0xF0000200
+#define UART1_IO_BASE 0xF0000300
+#endif
#define BASE_BAUD 11059200/16
#define STD_UART_OP(num) \
{ 0, BASE_BAUD, 0, UART##num##_INT, \
(ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST), \
- iomem_base: UART##num##_IO_BASE, \
+ iomem_base: (void*)UART##num##_IO_BASE, \
io_type: SERIAL_IO_MEM},
#define SERIAL_PORT_DFNS \
--
cgit v1.2.3-18-g5258