[PATCH 2/4] powerpc: move the exception trampoline helper functions to a separate file

[Kevin Hao <haokexin@gmail.com>]

For some platform such as 6xx we need to setup the exception
trampoline for a relocatable kernel even through the CONFIG_CRASH_DUMP
is disabled. So move these functions to a separate file so they can
be used by non dump kernel.  This patch doesn't introduce any function
change.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
---
 arch/powerpc/include/asm/exception_trampoline.h | 35 +++++++++++++
 arch/powerpc/include/asm/kdump.h                | 32 -----------
 arch/powerpc/kernel/Makefile                    |  2 +-
 arch/powerpc/kernel/crash_dump.c                | 41 ---------------
 arch/powerpc/kernel/exception_trampoline.c      | 70 +++++++++++++++++++++++++
 arch/powerpc/kernel/prom.c                      |  2 +-
 arch/powerpc/kernel/setup_32.c                  |  1 +
 arch/powerpc/kernel/setup_64.c                  |  2 +-
 8 files changed, 109 insertions(+), 76 deletions(-)
 create mode 100644 arch/powerpc/include/asm/exception_trampoline.h
 create mode 100644 arch/powerpc/kernel/exception_trampoline.c

diff --git a/arch/powerpc/include/asm/exception_trampoline.h b/arch/powerpc/include/asm/exception_trampoline.h
new file mode 100644
index 0000000..707ad6c
--- /dev/null
+++ b/arch/powerpc/include/asm/exception_trampoline.h
@@ -0,0 +1,35 @@
+#ifndef _EXCEPTION_TRAMPOLINE_H
+#define _EXCEPTION_TRAMPOLINE_H
+
+/* How many bytes to reserve at zero for kdump. The reserve limit should
+ * be greater or equal to the trampoline's end address.
+ * Reserve to the end of the FWNMI area, see head_64.S */
+#define KDUMP_RESERVE_LIMIT	0x10000 /* 64K */
+
+/*
+ * On PPC64 translation is disabled during trampoline setup, so we use
+ * physical addresses. Though on PPC32 translation is already enabled,
+ * so we can't do the same. Luckily create_trampoline() creates relative
+ * branches, so we can just add the PAGE_OFFSET and don't worry about it.
+ */
+#ifdef __powerpc64__
+#define KDUMP_TRAMPOLINE_START	0x0100
+#define KDUMP_TRAMPOLINE_END	0x3000
+#else
+#define KDUMP_TRAMPOLINE_START	(0x0100 + PAGE_OFFSET)
+#define KDUMP_TRAMPOLINE_END	(0x3000 + PAGE_OFFSET)
+#endif /* __powerpc64__ */
+
+#ifndef __ASSEMBLY__
+
+#if defined(CONFIG_CRASH_DUMP) && !defined(CONFIG_NONSTATIC_KERNEL)
+extern void reserve_kdump_trampoline(void);
+extern void setup_kdump_trampoline(void);
+#else
+/* !CRASH_DUMP || !NONSTATIC_KERNEL */
+static inline void reserve_kdump_trampoline(void) { ; }
+static inline void setup_kdump_trampoline(void) { ; }
+#endif
+
+#endif /* __ASSEMBLY__ */
+#endif /* _EXCEPTION_TRAMPOLINE_H */
diff --git a/arch/powerpc/include/asm/kdump.h b/arch/powerpc/include/asm/kdump.h
index c977620..7ac3553 100644
--- a/arch/powerpc/include/asm/kdump.h
+++ b/arch/powerpc/include/asm/kdump.h
@@ -5,42 +5,10 @@
 
 #define KDUMP_KERNELBASE	0x2000000
 
-/* How many bytes to reserve at zero for kdump. The reserve limit should
- * be greater or equal to the trampoline's end address.
- * Reserve to the end of the FWNMI area, see head_64.S */
-#define KDUMP_RESERVE_LIMIT	0x10000 /* 64K */
-
 #ifdef CONFIG_CRASH_DUMP
 
-/*
- * On PPC64 translation is disabled during trampoline setup, so we use
- * physical addresses. Though on PPC32 translation is already enabled,
- * so we can't do the same. Luckily create_trampoline() creates relative
- * branches, so we can just add the PAGE_OFFSET and don't worry about it.
- */
-#ifdef __powerpc64__
-#define KDUMP_TRAMPOLINE_START	0x0100
-#define KDUMP_TRAMPOLINE_END	0x3000
-#else
-#define KDUMP_TRAMPOLINE_START	(0x0100 + PAGE_OFFSET)
-#define KDUMP_TRAMPOLINE_END	(0x3000 + PAGE_OFFSET)
-#endif /* __powerpc64__ */
-
 #define KDUMP_MIN_TCE_ENTRIES	2048
 
 #endif /* CONFIG_CRASH_DUMP */
 
-#ifndef __ASSEMBLY__
-
-#if defined(CONFIG_CRASH_DUMP) && !defined(CONFIG_NONSTATIC_KERNEL)
-extern void reserve_kdump_trampoline(void);
-extern void setup_kdump_trampoline(void);
-#else
-/* !CRASH_DUMP || !NONSTATIC_KERNEL */
-static inline void reserve_kdump_trampoline(void) { ; }
-static inline void setup_kdump_trampoline(void) { ; }
-#endif
-
-#endif /* __ASSEMBLY__ */
-
 #endif /* __PPC64_KDUMP_H */
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index f960a79..c73a0e3 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -59,7 +59,7 @@ obj-$(CONFIG_LPARCFG)		+= lparcfg.o
 obj-$(CONFIG_IBMVIO)		+= vio.o
 obj-$(CONFIG_IBMEBUS)           += ibmebus.o
 obj-$(CONFIG_GENERIC_TBSYNC)	+= smp-tbsync.o
-obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
+obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o exception_trampoline.o
 obj-$(CONFIG_FA_DUMP)		+= fadump.o
 ifeq ($(CONFIG_PPC32),y)
 obj-$(CONFIG_E500)		+= idle_e500.o
diff --git a/arch/powerpc/kernel/crash_dump.c b/arch/powerpc/kernel/crash_dump.c
index 9ec3fe1..56dab87 100644
--- a/arch/powerpc/kernel/crash_dump.c
+++ b/arch/powerpc/kernel/crash_dump.c
@@ -28,47 +28,6 @@
 #define DBG(fmt...)
 #endif
 
-#ifndef CONFIG_NONSTATIC_KERNEL
-void __init reserve_kdump_trampoline(void)
-{
-	memblock_reserve(0, KDUMP_RESERVE_LIMIT);
-}
-
-static void __init create_trampoline(unsigned long addr)
-{
-	unsigned int *p = (unsigned int *)addr;
-
-	/* The maximum range of a single instruction branch, is the current
-	 * instruction's address + (32 MB - 4) bytes. For the trampoline we
-	 * need to branch to current address + 32 MB. So we insert a nop at
-	 * the trampoline address, then the next instruction (+ 4 bytes)
-	 * does a branch to (32 MB - 4). The net effect is that when we
-	 * branch to "addr" we jump to ("addr" + 32 MB). Although it requires
-	 * two instructions it doesn't require any registers.
-	 */
-	patch_instruction(p, PPC_INST_NOP);
-	patch_branch(++p, addr + PHYSICAL_START, 0);
-}
-
-void __init setup_kdump_trampoline(void)
-{
-	unsigned long i;
-
-	DBG(" -> setup_kdump_trampoline()\n");
-
-	for (i = KDUMP_TRAMPOLINE_START; i < KDUMP_TRAMPOLINE_END; i += 8) {
-		create_trampoline(i);
-	}
-
-#ifdef CONFIG_PPC_PSERIES
-	create_trampoline(__pa(system_reset_fwnmi) - PHYSICAL_START);
-	create_trampoline(__pa(machine_check_fwnmi) - PHYSICAL_START);
-#endif /* CONFIG_PPC_PSERIES */
-
-	DBG(" <- setup_kdump_trampoline()\n");
-}
-#endif /* CONFIG_NONSTATIC_KERNEL */
-
 static int __init parse_savemaxmem(char *p)
 {
 	if (p)
diff --git a/arch/powerpc/kernel/exception_trampoline.c b/arch/powerpc/kernel/exception_trampoline.c
new file mode 100644
index 0000000..71f4b72
--- /dev/null
+++ b/arch/powerpc/kernel/exception_trampoline.c
@@ -0,0 +1,70 @@
+/*
+ * Routines for doing kexec-based kdump.
+ *
+ * Copyright (C) 2005, IBM Corp.
+ *
+ * Created by: Michael Ellerman
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
+
+#undef DEBUG
+
+#include <linux/crash_dump.h>
+#include <linux/bootmem.h>
+#include <linux/memblock.h>
+#include <asm/code-patching.h>
+#include <asm/kdump.h>
+#include <asm/prom.h>
+#include <asm/firmware.h>
+#include <asm/uaccess.h>
+#include <asm/rtas.h>
+
+#ifdef DEBUG
+#include <asm/udbg.h>
+#define DBG(fmt...) udbg_printf(fmt)
+#else
+#define DBG(fmt...)
+#endif
+
+#ifndef CONFIG_NONSTATIC_KERNEL
+void __init reserve_kdump_trampoline(void)
+{
+	memblock_reserve(0, KDUMP_RESERVE_LIMIT);
+}
+
+static void __init create_trampoline(unsigned long addr)
+{
+	unsigned int *p = (unsigned int *)addr;
+
+	/* The maximum range of a single instruction branch, is the current
+	 * instruction's address + (32 MB - 4) bytes. For the trampoline we
+	 * need to branch to current address + 32 MB. So we insert a nop at
+	 * the trampoline address, then the next instruction (+ 4 bytes)
+	 * does a branch to (32 MB - 4). The net effect is that when we
+	 * branch to "addr" we jump to ("addr" + 32 MB). Although it requires
+	 * two instructions it doesn't require any registers.
+	 */
+	patch_instruction(p, PPC_INST_NOP);
+	patch_branch(++p, addr + PHYSICAL_START, 0);
+}
+
+void __init setup_kdump_trampoline(void)
+{
+	unsigned long i;
+
+	DBG(" -> setup_kdump_trampoline()\n");
+
+	for (i = KDUMP_TRAMPOLINE_START; i < KDUMP_TRAMPOLINE_END; i += 8) {
+		create_trampoline(i);
+	}
+
+#ifdef CONFIG_PPC_PSERIES
+	create_trampoline(__pa(system_reset_fwnmi) - PHYSICAL_START);
+	create_trampoline(__pa(machine_check_fwnmi) - PHYSICAL_START);
+#endif /* CONFIG_PPC_PSERIES */
+
+	DBG(" <- setup_kdump_trampoline()\n");
+}
+#endif /* CONFIG_NONSTATIC_KERNEL */
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 8b6f7a9..4a13ac5 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -40,7 +40,7 @@
 #include <asm/processor.h>
 #include <asm/irq.h>
 #include <asm/io.h>
-#include <asm/kdump.h>
+#include <asm/exception_trampoline.h>
 #include <asm/smp.h>
 #include <asm/mmu.h>
 #include <asm/paca.h>
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index a8f54ec..9f3aa43 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -38,6 +38,7 @@
 #include <asm/serial.h>
 #include <asm/udbg.h>
 #include <asm/mmu_context.h>
+#include <asm/exception_trampoline.h>
 
 #include "setup.h"
 
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index e379d3f..06b8562 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -38,7 +38,7 @@
 #include <linux/hugetlb.h>
 
 #include <asm/io.h>
-#include <asm/kdump.h>
+#include <asm/exception_trampoline.h>
 #include <asm/prom.h>
 #include <asm/processor.h>
 #include <asm/pgtable.h>
-- 
1.8.1.4