[PATCH 10/14] Early serial debug support for PPC44x
David Gibson
david at gibson.dropbear.id.au
Tue Feb 20 13:12:35 EST 2007
This patch adds support for early serial debugging via the built in
port on IBM/AMCC PowerPC 44x CPUs. It uses a bolted TLB entry in
address space 1 for the UART's mapping, allowing robust debugging both
before and after the initialization of the MMU.
Signed-off-by: David Gibson <dwg at au1.ibm.com>
---
arch/powerpc/Kconfig.debug | 23 ++++++++++++++-----
arch/powerpc/kernel/Makefile | 1
arch/powerpc/kernel/head_44x.S | 34 ++++++++++------------------
arch/powerpc/kernel/misc_44x.S | 46 ++++++++++++++++++++++++++++++++++++++
arch/powerpc/kernel/of_platform.c | 1
arch/powerpc/kernel/udbg.c | 3 ++
arch/powerpc/kernel/udbg_16550.c | 24 +++++++++++++++++++
include/asm-powerpc/mmu_44x.h | 7 ++++-
include/asm-powerpc/udbg.h | 1
9 files changed, 112 insertions(+), 28 deletions(-)
Index: working-2.6/arch/powerpc/Kconfig.debug
===================================================================
--- working-2.6.orig/arch/powerpc/Kconfig.debug 2007-02-20 11:06:54.000000000 +1100
+++ working-2.6/arch/powerpc/Kconfig.debug 2007-02-20 11:07:36.000000000 +1100
@@ -130,11 +130,6 @@ config BOOTX_TEXT
Say Y here to see progress messages from the boot firmware in text
mode. Requires either BootX or Open Firmware.
-config SERIAL_TEXT_DEBUG
- bool "Support for early boot texts over serial port"
- depends on 4xx || LOPEC || MV64X60 || PPLUS || PRPMC800 || \
- PPC_GEN550 || PPC_MPC52xx
-
config PPC_EARLY_DEBUG
bool "Early debugging (dangerous)"
@@ -199,6 +194,24 @@ config PPC_EARLY_DEBUG_BEAT
help
Select this to enable early debugging for Celleb with Beat.
+config PPC_EARLY_DEBUG_44x
+ bool "Early serial debugging for IBM 44x CPUs"
+ depends on 44x
+ select PPC_UDBG_16550
+ help
+ Select this to enable early debugging for IBM 44x chips via the
+ inbuilt serial port.
+
endchoice
+config PPC_EARLY_DEBUG_44x_PHYSLOW
+ hex
+ depends PPC_EARLY_DEBUG_44x
+ default "0x40000200"
+
+config PPC_EARLY_DEBUG_44x_PHYSHIGH
+ hex
+ depends PPC_EARLY_DEBUG_44x
+ default "0x1"
+
endmenu
Index: working-2.6/arch/powerpc/kernel/head_44x.S
===================================================================
--- working-2.6.orig/arch/powerpc/kernel/head_44x.S 2007-02-20 11:06:54.000000000 +1100
+++ working-2.6/arch/powerpc/kernel/head_44x.S 2007-02-20 11:07:36.000000000 +1100
@@ -172,36 +172,28 @@ skpinv: addi r4,r4,1 /* Increment */
isync
4:
-#ifdef CONFIG_SERIAL_TEXT_DEBUG
- /*
- * 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
- */
+#ifdef CONFIG_PPC_EARLY_DEBUG_44x
+ /* Add UART mapping for early debug. */
+
/* pageid fields */
- lis r3,UART0_IO_BASE at h
- ori r3,r3,PPC44x_TLB_VALID | PPC44x_TLB_4K
+ lis r3,PPC44x_EARLY_DEBUG_VIRTADDR at h
+ ori r3,r3,PPC44x_TLB_VALID|PPC44x_TLB_TS|PPC44x_TLB_64K
/* xlat fields */
- lis r4,UART0_PHYS_IO_BASE at h /* RPN depends on SoC */
-#ifndef CONFIG_440EP
- ori r4,r4,0x0001 /* ERPN is 1 for second 4GB page */
-#endif
+ lis r4,CONFIG_PPC_EARLY_DEBUG_44x_PHYSLOW at h
+ ori r4,r4,CONFIG_PPC_EARLY_DEBUG_44x_PHYSHIGH
/* attrib fields */
- li r5,0
- ori r5,r5,(PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_I | PPC44x_TLB_G)
-
- li r0,0 /* TLB slot 0 */
+ li r5,(PPC44x_TLB_SW|PPC44x_TLB_SR|PPC44x_TLB_I|PPC44x_TLB_G)
+ li r0,62 /* TLB slot 0 */
- tlbwe r3,r0,PPC44x_TLB_PAGEID /* Load the pageid fields */
- tlbwe r4,r0,PPC44x_TLB_XLAT /* Load the translation fields */
- tlbwe r5,r0,PPC44x_TLB_ATTRIB /* Load the attrib/access fields */
+ tlbwe r3,r0,PPC44x_TLB_PAGEID
+ tlbwe r4,r0,PPC44x_TLB_XLAT
+ tlbwe r5,r0,PPC44x_TLB_ATTRIB
/* Force context change */
isync
-#endif /* CONFIG_SERIAL_TEXT_DEBUG */
+#endif /* CONFIG_PPC_EARLY_DEBUG_44x */
/* Establish the interrupt vector offsets */
SET_IVOR(0, CriticalInput);
Index: working-2.6/arch/powerpc/kernel/udbg_16550.c
===================================================================
--- working-2.6.orig/arch/powerpc/kernel/udbg_16550.c 2007-02-20 11:06:54.000000000 +1100
+++ working-2.6/arch/powerpc/kernel/udbg_16550.c 2007-02-20 11:07:36.000000000 +1100
@@ -191,3 +191,27 @@ void udbg_init_pas_realmode(void)
udbg_getc_poll = NULL;
}
#endif /* CONFIG_PPC_MAPLE */
+
+#ifdef CONFIG_PPC_EARLY_DEBUG_44x
+extern u8 as1_readb(volatile u8 __iomem *addr);
+extern void as1_writeb(u8 data, volatile u8 __iomem *addr);
+
+static void udbg_44x_as1_putc(char c)
+{
+ if (udbg_comport) {
+ while ((as1_readb(&udbg_comport->lsr) & LSR_THRE) == 0)
+ /* wait for idle */;
+ as1_writeb(c, &udbg_comport->thr); eieio();
+ if (c == '\n')
+ udbg_44x_as1_putc('\r');
+ }
+}
+
+void __init udbg_init_44x_as1(void)
+{
+ udbg_comport =
+ (volatile struct NS16550 __iomem *)PPC44x_EARLY_DEBUG_VIRTADDR;
+
+ udbg_putc = udbg_44x_as1_putc;
+}
+#endif /* CONFIG_PPC_EARLY_DEBUG_44x */
Index: working-2.6/include/asm-powerpc/mmu_44x.h
===================================================================
--- working-2.6.orig/include/asm-powerpc/mmu_44x.h 2007-02-20 11:06:54.000000000 +1100
+++ working-2.6/include/asm-powerpc/mmu_44x.h 2007-02-20 11:07:36.000000000 +1100
@@ -68,7 +68,12 @@ typedef struct {
#define PPC44x_PIN_SHIFT 28
#define PPC_PIN_SIZE (1 << PPC44x_PIN_SHIFT)
+#ifndef CONFIG_PPC_EARLY_DEBUG_44x
#define PPC44x_EARLY_TLBS 1
+#else
+#define PPC44x_EARLY_TLBS 2
+#define PPC44x_EARLY_DEBUG_VIRTADDR (ASM_CONST(0xf0000000) \
+ | (ASM_CONST(CONFIG_PPC_EARLY_DEBUG_44x_PHYSLOW) & 0xffff))
+#endif
#endif /* _ASM_POWERPC_MMU_44X_H_ */
-
Index: working-2.6/arch/powerpc/kernel/udbg.c
===================================================================
--- working-2.6.orig/arch/powerpc/kernel/udbg.c 2007-02-20 11:06:54.000000000 +1100
+++ working-2.6/arch/powerpc/kernel/udbg.c 2007-02-20 11:07:36.000000000 +1100
@@ -51,6 +51,9 @@ void __init udbg_early_init(void)
udbg_init_pas_realmode();
#elif defined(CONFIG_BOOTX_TEXT)
udbg_init_btext();
+#elif defined(CONFIG_PPC_EARLY_DEBUG_44x)
+ /* PPC44x debug */
+ udbg_init_44x_as1();
#endif
}
Index: working-2.6/include/asm-powerpc/udbg.h
===================================================================
--- working-2.6.orig/include/asm-powerpc/udbg.h 2007-02-20 11:06:54.000000000 +1100
+++ working-2.6/include/asm-powerpc/udbg.h 2007-02-20 11:07:36.000000000 +1100
@@ -47,6 +47,7 @@ extern void __init udbg_init_rtas_panel(
extern void __init udbg_init_rtas_console(void);
extern void __init udbg_init_debug_beat(void);
extern void __init udbg_init_btext(void);
+extern void __init udbg_init_44x_as1(void);
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_UDBG_H */
Index: working-2.6/arch/powerpc/kernel/Makefile
===================================================================
--- working-2.6.orig/arch/powerpc/kernel/Makefile 2007-02-20 11:06:54.000000000 +1100
+++ working-2.6/arch/powerpc/kernel/Makefile 2007-02-20 11:07:36.000000000 +1100
@@ -53,6 +53,7 @@ obj-y += time.o prom.o traps.o setup-
udbg.o misc.o io.o
obj-$(CONFIG_PPC32) += entry_32.o setup_32.o misc_32.o
obj-$(CONFIG_PPC64) += misc_64.o dma_64.o iommu.o
+obj-$(CONFIG_44x) += misc_44x.o
obj-$(CONFIG_PPC_MULTIPLATFORM) += prom_init.o
obj-$(CONFIG_MODULES) += ppc_ksyms.o
obj-$(CONFIG_BOOTX_TEXT) += btext.o
Index: working-2.6/arch/powerpc/kernel/misc_44x.S
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ working-2.6/arch/powerpc/kernel/misc_44x.S 2007-02-20 11:07:36.000000000 +1100
@@ -0,0 +1,46 @@
+/*
+ * This file contains miscellaneous low-level functions for PPC 44x.
+ * Copyright 2007 David Gibson <dwg at au1.ibm.com>, IBM Corporation.
+ *
+ * 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 Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <asm/reg.h>
+#include <asm/ppc_asm.h>
+
+ .text
+
+/*
+ * Do an IO access in AS1
+ */
+_GLOBAL(as1_readb)
+ mfmsr r7
+ ori r0,r7,MSR_DS
+ sync
+ mtmsr r0
+ sync
+ isync
+ lbz r3,0(r3)
+ sync
+ mtmsr r7
+ sync
+ isync
+ blr
+
+_GLOBAL(as1_writeb)
+ mfmsr r7
+ ori r0,r7,MSR_DS
+ sync
+ mtmsr r0
+ sync
+ isync
+ stb r3,0(r4)
+ sync
+ mtmsr r7
+ sync
+ isync
+ blr
Index: working-2.6/arch/powerpc/kernel/of_platform.c
===================================================================
--- working-2.6.orig/arch/powerpc/kernel/of_platform.c 2007-02-20 11:06:54.000000000 +1100
+++ working-2.6/arch/powerpc/kernel/of_platform.c 2007-02-20 11:16:56.000000000 +1100
@@ -29,7 +29,6 @@
#include <asm/ppc-pci.h>
#include <asm/atomic.h>
-
/*
* The list of OF IDs below is used for matching bus types in the
* system whose devices are to be exposed as of_platform_devices.
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