[PATCH 15/15] powerpc: Add early debug for WSP platforms
Michael Ellerman
michael at ozlabs.org
Fri Apr 15 18:32:08 EST 2011
From: Jack Miller <jack at codezen.org>
Signed-off-by: Jack Miller <jack at codezen.org>
Signed-off-by: Michael Ellerman <michael at ellerman.id.au>
---
arch/powerpc/Kconfig.debug | 5 +++
arch/powerpc/include/asm/reg_a2.h | 9 ++++++
arch/powerpc/include/asm/udbg.h | 1 +
arch/powerpc/kernel/exceptions-64e.S | 17 +++++++++++
arch/powerpc/kernel/udbg.c | 2 +
arch/powerpc/kernel/udbg_16550.c | 51 ++++++++++++++++++++++++++++++++++
6 files changed, 85 insertions(+), 0 deletions(-)
diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug
index 2d38a50..a597dd7 100644
--- a/arch/powerpc/Kconfig.debug
+++ b/arch/powerpc/Kconfig.debug
@@ -267,6 +267,11 @@ config PPC_EARLY_DEBUG_USBGECKO
Select this to enable early debugging for Nintendo GameCube/Wii
consoles via an external USB Gecko adapter.
+config PPC_EARLY_DEBUG_WSP
+ bool "Early debugging via WSP's internal UART"
+ depends on PPC_WSP
+ select PPC_UDBG_16550
+
endchoice
config PPC_EARLY_DEBUG_44x_PHYSLOW
diff --git a/arch/powerpc/include/asm/reg_a2.h b/arch/powerpc/include/asm/reg_a2.h
index 3ba9c6f..3d52a11 100644
--- a/arch/powerpc/include/asm/reg_a2.h
+++ b/arch/powerpc/include/asm/reg_a2.h
@@ -110,6 +110,15 @@
#define TLB1_UR ASM_CONST(0x0000000000000002)
#define TLB1_SR ASM_CONST(0x0000000000000001)
+#ifdef CONFIG_PPC_EARLY_DEBUG_WSP
+#define WSP_UART_PHYS 0xffc000c000
+/* This needs to be careful chosen to hit a !0 congruence class
+ * in the TLB since we bolt it in way 3, which is already occupied
+ * by our linear mapping primary bolted entry in CC 0.
+ */
+#define WSP_UART_VIRT 0xf000000000001000
+#endif
+
/* A2 erativax attributes definitions */
#define ERATIVAX_RS_IS_ALL 0x000
#define ERATIVAX_RS_IS_TID 0x040
diff --git a/arch/powerpc/include/asm/udbg.h b/arch/powerpc/include/asm/udbg.h
index 11ae699..58580e9 100644
--- a/arch/powerpc/include/asm/udbg.h
+++ b/arch/powerpc/include/asm/udbg.h
@@ -52,6 +52,7 @@ extern void __init udbg_init_44x_as1(void);
extern void __init udbg_init_40x_realmode(void);
extern void __init udbg_init_cpm(void);
extern void __init udbg_init_usbgecko(void);
+extern void __init udbg_init_wsp(void);
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_UDBG_H */
diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
index 8e5d2c1..f4ed2cb 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -17,6 +17,7 @@
#include <asm/cputable.h>
#include <asm/setup.h>
#include <asm/thread_info.h>
+#include <asm/reg_a2.h>
#include <asm/exception-64e.h>
#include <asm/bug.h>
#include <asm/irqflags.h>
@@ -951,6 +952,22 @@ a2_tlbinit_after_linear_map:
.globl a2_tlbinit_after_iprot_flush
a2_tlbinit_after_iprot_flush:
+#ifdef CONFIG_PPC_EARLY_DEBUG_WSP
+ /* Now establish early debug mappings if applicable */
+ /* Restore the MAS0 we used for linear mapping load */
+ mtspr SPRN_MAS0,r11
+
+ lis r3,(MAS1_VALID | MAS1_IPROT)@h
+ ori r3,r3,(BOOK3E_PAGESZ_4K << MAS1_TSIZE_SHIFT)
+ mtspr SPRN_MAS1,r3
+ LOAD_REG_IMMEDIATE(r3, WSP_UART_VIRT | MAS2_I | MAS2_G)
+ mtspr SPRN_MAS2,r3
+ LOAD_REG_IMMEDIATE(r3, WSP_UART_PHYS | MAS3_SR | MAS3_SW)
+ mtspr SPRN_MAS7_MAS3,r3
+ /* re-use the MAS8 value from the linear mapping */
+ tlbwe
+#endif /* CONFIG_PPC_EARLY_DEBUG_WSP */
+
PPC_TLBILX(0,0,0)
sync
isync
diff --git a/arch/powerpc/kernel/udbg.c b/arch/powerpc/kernel/udbg.c
index e39cad8..23d65ab 100644
--- a/arch/powerpc/kernel/udbg.c
+++ b/arch/powerpc/kernel/udbg.c
@@ -62,6 +62,8 @@ void __init udbg_early_init(void)
udbg_init_cpm();
#elif defined(CONFIG_PPC_EARLY_DEBUG_USBGECKO)
udbg_init_usbgecko();
+#elif defined(CONFIG_PPC_EARLY_DEBUG_WSP)
+ udbg_init_wsp();
#endif
#ifdef CONFIG_PPC_EARLY_DEBUG
diff --git a/arch/powerpc/kernel/udbg_16550.c b/arch/powerpc/kernel/udbg_16550.c
index b4b167b..ed7ac57 100644
--- a/arch/powerpc/kernel/udbg_16550.c
+++ b/arch/powerpc/kernel/udbg_16550.c
@@ -11,6 +11,7 @@
#include <linux/types.h>
#include <asm/udbg.h>
#include <asm/io.h>
+#include <asm/reg_a2.h>
extern u8 real_readb(volatile u8 __iomem *addr);
extern void real_writeb(u8 data, volatile u8 __iomem *addr);
@@ -298,3 +299,53 @@ void __init udbg_init_40x_realmode(void)
udbg_getc_poll = NULL;
}
#endif /* CONFIG_PPC_EARLY_DEBUG_40x */
+
+#ifdef CONFIG_PPC_EARLY_DEBUG_WSP
+static void udbg_wsp_flush(void)
+{
+ if (udbg_comport) {
+ while ((readb(&udbg_comport->lsr) & LSR_THRE) == 0)
+ /* wait for idle */;
+ }
+}
+
+static void udbg_wsp_putc(char c)
+{
+ if (udbg_comport) {
+ if (c == '\n')
+ udbg_wsp_putc('\r');
+ udbg_wsp_flush();
+ writeb(c, &udbg_comport->thr); eieio();
+ }
+}
+
+static int udbg_wsp_getc(void)
+{
+ if (udbg_comport) {
+ while ((readb(&udbg_comport->lsr) & LSR_DR) == 0)
+ ; /* wait for char */
+ return readb(&udbg_comport->rbr);
+ }
+ return -1;
+}
+
+static int udbg_wsp_getc_poll(void)
+{
+ if (udbg_comport)
+ if (readb(&udbg_comport->lsr) & LSR_DR)
+ return readb(&udbg_comport->rbr);
+ return -1;
+}
+
+void __init udbg_init_wsp(void)
+{
+ udbg_comport = (struct NS16550 __iomem *)WSP_UART_VIRT;
+
+ udbg_init_uart(udbg_comport, 57600, 50000000);
+
+ udbg_putc = udbg_wsp_putc;
+ udbg_flush = udbg_wsp_flush;
+ udbg_getc = udbg_wsp_getc;
+ udbg_getc_poll = udbg_wsp_getc_poll;
+}
+#endif /* CONFIG_PPC_EARLY_DEBUG_WSP */
--
1.7.1
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