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authorDavid Gibson <david@gibson.dropbear.id.au>2007-05-07 22:59:31 -0400
committerPaul Mackerras <paulus@samba.org>2007-05-08 00:47:33 -0400
commitd9b55a03611ff2e2e54fb4e1ad2648d5eb870fa3 (patch)
tree5704be539afcd6f29b1f5751476c8b4f53673bff /arch/powerpc
parentf6dfc80554b27da11dbb36ebae166b23ec3aa9ca (diff)
[POWERPC] Early serial debug support for PPC44x
This 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@au1.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/Kconfig.debug22
-rw-r--r--arch/powerpc/kernel/head_44x.S34
-rw-r--r--arch/powerpc/kernel/of_platform.c1
-rw-r--r--arch/powerpc/kernel/udbg.c3
-rw-r--r--arch/powerpc/kernel/udbg_16550.c23
-rw-r--r--arch/powerpc/platforms/44x/44x.h2
-rw-r--r--arch/powerpc/platforms/44x/misc_44x.S31
7 files changed, 90 insertions, 26 deletions
diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug
index 86aa3745af7f..f70e795c262e 100644
--- a/arch/powerpc/Kconfig.debug
+++ b/arch/powerpc/Kconfig.debug
@@ -139,10 +139,6 @@ config BOOTX_TEXT
139 Say Y here to see progress messages from the boot firmware in text 139 Say Y here to see progress messages from the boot firmware in text
140 mode. Requires either BootX or Open Firmware. 140 mode. Requires either BootX or Open Firmware.
141 141
142config SERIAL_TEXT_DEBUG
143 bool "Support for early boot texts over serial port"
144 depends on 4xx
145
146config PPC_EARLY_DEBUG 142config PPC_EARLY_DEBUG
147 bool "Early debugging (dangerous)" 143 bool "Early debugging (dangerous)"
148 144
@@ -207,6 +203,24 @@ config PPC_EARLY_DEBUG_BEAT
207 help 203 help
208 Select this to enable early debugging for Celleb with Beat. 204 Select this to enable early debugging for Celleb with Beat.
209 205
206config PPC_EARLY_DEBUG_44x
207 bool "Early serial debugging for IBM/AMCC 44x CPUs"
208 depends on 44x
209 select PPC_UDBG_16550
210 help
211 Select this to enable early debugging for IBM 44x chips via the
212 inbuilt serial port.
213
210endchoice 214endchoice
211 215
216config PPC_EARLY_DEBUG_44x_PHYSLOW
217 hex "Low 32 bits of early debug UART physical address"
218 depends PPC_EARLY_DEBUG_44x
219 default "0x40000200"
220
221config PPC_EARLY_DEBUG_44x_PHYSHIGH
222 hex "EPRN of early debug UART physical address"
223 depends PPC_EARLY_DEBUG_44x
224 default "0x1"
225
212endmenu 226endmenu
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index a51026f0a9d7..88695963f587 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -172,36 +172,28 @@ skpinv: addi r4,r4,1 /* Increment */
172 isync 172 isync
173 173
1744: 1744:
175#ifdef CONFIG_SERIAL_TEXT_DEBUG 175#ifdef CONFIG_PPC_EARLY_DEBUG_44x
176 /* 176 /* Add UART mapping for early debug. */
177 * Add temporary UART mapping for early debug. 177
178 * We can map UART registers wherever we want as long as they don't
179 * interfere with other system mappings (e.g. with pinned entries).
180 * For an example of how we handle this - see ocotea.h. --ebs
181 */
182 /* pageid fields */ 178 /* pageid fields */
183 lis r3,UART0_IO_BASE@h 179 lis r3,PPC44x_EARLY_DEBUG_VIRTADDR@h
184 ori r3,r3,PPC44x_TLB_VALID | PPC44x_TLB_4K 180 ori r3,r3,PPC44x_TLB_VALID|PPC44x_TLB_TS|PPC44x_TLB_64K
185 181
186 /* xlat fields */ 182 /* xlat fields */
187 lis r4,UART0_PHYS_IO_BASE@h /* RPN depends on SoC */ 183 lis r4,CONFIG_PPC_EARLY_DEBUG_44x_PHYSLOW@h
188#ifndef CONFIG_440EP 184 ori r4,r4,CONFIG_PPC_EARLY_DEBUG_44x_PHYSHIGH
189 ori r4,r4,0x0001 /* ERPN is 1 for second 4GB page */
190#endif
191 185
192 /* attrib fields */ 186 /* attrib fields */
193 li r5,0 187 li r5,(PPC44x_TLB_SW|PPC44x_TLB_SR|PPC44x_TLB_I|PPC44x_TLB_G)
194 ori r5,r5,(PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_I | PPC44x_TLB_G) 188 li r0,62 /* TLB slot 0 */
195 189
196 li r0,0 /* TLB slot 0 */ 190 tlbwe r3,r0,PPC44x_TLB_PAGEID
197 191 tlbwe r4,r0,PPC44x_TLB_XLAT
198 tlbwe r3,r0,PPC44x_TLB_PAGEID /* Load the pageid fields */ 192 tlbwe r5,r0,PPC44x_TLB_ATTRIB
199 tlbwe r4,r0,PPC44x_TLB_XLAT /* Load the translation fields */
200 tlbwe r5,r0,PPC44x_TLB_ATTRIB /* Load the attrib/access fields */
201 193
202 /* Force context change */ 194 /* Force context change */
203 isync 195 isync
204#endif /* CONFIG_SERIAL_TEXT_DEBUG */ 196#endif /* CONFIG_PPC_EARLY_DEBUG_44x */
205 197
206 /* Establish the interrupt vector offsets */ 198 /* Establish the interrupt vector offsets */
207 SET_IVOR(0, CriticalInput); 199 SET_IVOR(0, CriticalInput);
diff --git a/arch/powerpc/kernel/of_platform.c b/arch/powerpc/kernel/of_platform.c
index 908ed7926db4..84c34d979a88 100644
--- a/arch/powerpc/kernel/of_platform.c
+++ b/arch/powerpc/kernel/of_platform.c
@@ -29,7 +29,6 @@
29#include <asm/ppc-pci.h> 29#include <asm/ppc-pci.h>
30#include <asm/atomic.h> 30#include <asm/atomic.h>
31 31
32
33/* 32/*
34 * The list of OF IDs below is used for matching bus types in the 33 * The list of OF IDs below is used for matching bus types in the
35 * system whose devices are to be exposed as of_platform_devices. 34 * system whose devices are to be exposed as of_platform_devices.
diff --git a/arch/powerpc/kernel/udbg.c b/arch/powerpc/kernel/udbg.c
index 7e0971868fc2..7ef97ea8b3ef 100644
--- a/arch/powerpc/kernel/udbg.c
+++ b/arch/powerpc/kernel/udbg.c
@@ -51,6 +51,9 @@ void __init udbg_early_init(void)
51 udbg_init_pas_realmode(); 51 udbg_init_pas_realmode();
52#elif defined(CONFIG_BOOTX_TEXT) 52#elif defined(CONFIG_BOOTX_TEXT)
53 udbg_init_btext(); 53 udbg_init_btext();
54#elif defined(CONFIG_PPC_EARLY_DEBUG_44x)
55 /* PPC44x debug */
56 udbg_init_44x_as1();
54#endif 57#endif
55} 58}
56 59
diff --git a/arch/powerpc/kernel/udbg_16550.c b/arch/powerpc/kernel/udbg_16550.c
index a963f657222b..7afab5bcd61a 100644
--- a/arch/powerpc/kernel/udbg_16550.c
+++ b/arch/powerpc/kernel/udbg_16550.c
@@ -191,3 +191,26 @@ void udbg_init_pas_realmode(void)
191 udbg_getc_poll = NULL; 191 udbg_getc_poll = NULL;
192} 192}
193#endif /* CONFIG_PPC_MAPLE */ 193#endif /* CONFIG_PPC_MAPLE */
194
195#ifdef CONFIG_PPC_EARLY_DEBUG_44x
196#include <platforms/44x/44x.h>
197
198static void udbg_44x_as1_putc(char c)
199{
200 if (udbg_comport) {
201 while ((as1_readb(&udbg_comport->lsr) & LSR_THRE) == 0)
202 /* wait for idle */;
203 as1_writeb(c, &udbg_comport->thr); eieio();
204 if (c == '\n')
205 udbg_44x_as1_putc('\r');
206 }
207}
208
209void __init udbg_init_44x_as1(void)
210{
211 udbg_comport =
212 (volatile struct NS16550 __iomem *)PPC44x_EARLY_DEBUG_VIRTADDR;
213
214 udbg_putc = udbg_44x_as1_putc;
215}
216#endif /* CONFIG_PPC_EARLY_DEBUG_44x */
diff --git a/arch/powerpc/platforms/44x/44x.h b/arch/powerpc/platforms/44x/44x.h
index 45f24b166f4d..42eabf87fea3 100644
--- a/arch/powerpc/platforms/44x/44x.h
+++ b/arch/powerpc/platforms/44x/44x.h
@@ -1,6 +1,8 @@
1#ifndef __POWERPC_PLATFORMS_44X_44X_H 1#ifndef __POWERPC_PLATFORMS_44X_44X_H
2#define __POWERPC_PLATFORMS_44X_44X_H 2#define __POWERPC_PLATFORMS_44X_44X_H
3 3
4extern u8 as1_readb(volatile u8 __iomem *addr);
5extern void as1_writeb(u8 data, volatile u8 __iomem *addr);
4extern void ppc44x_reset_system(char *cmd); 6extern void ppc44x_reset_system(char *cmd);
5 7
6#endif /* __POWERPC_PLATFORMS_44X_44X_H */ 8#endif /* __POWERPC_PLATFORMS_44X_44X_H */
diff --git a/arch/powerpc/platforms/44x/misc_44x.S b/arch/powerpc/platforms/44x/misc_44x.S
index 52bde71485bd..3bce71d5d756 100644
--- a/arch/powerpc/platforms/44x/misc_44x.S
+++ b/arch/powerpc/platforms/44x/misc_44x.S
@@ -15,6 +15,37 @@
15 .text 15 .text
16 16
17/* 17/*
18 * Do an IO access in AS1
19 */
20_GLOBAL(as1_readb)
21 mfmsr r7
22 ori r0,r7,MSR_DS
23 sync
24 mtmsr r0
25 sync
26 isync
27 lbz r3,0(r3)
28 sync
29 mtmsr r7
30 sync
31 isync
32 blr
33
34_GLOBAL(as1_writeb)
35 mfmsr r7
36 ori r0,r7,MSR_DS
37 sync
38 mtmsr r0
39 sync
40 isync
41 stb r3,0(r4)
42 sync
43 mtmsr r7
44 sync
45 isync
46 blr
47
48/*
18 * void ppc44x_reset_system(char *cmd) 49 * void ppc44x_reset_system(char *cmd)
19 * 50 *
20 * At present, this routine just applies a system reset. 51 * At present, this routine just applies a system reset.