[PATCH 0/4] powerpc: enable relocatable support for 6xx

[PATCH 0/4] powerpc: enable relocatable support for 6xx

[Kevin Hao]

This patch series enables the relocatable support for 6xx boards.
With these patches:
  * the kernel can boot from any address between 0x10000 ~ 0x2000000
  * kdump is workable
  * a single kernel image can be used as boot or kdump kernel

Boot test on a mpc8260 board. Also passed the build test for the
following configurations:
	ppc40x_defconfig
        ppc64e_defconfig
        ppc64_defconfig
        corenet32_smp_defconfig
        corenet64_smp_defconfig
        ppc44x_defconfig
	pmac32_defconfig
	pq2fads_defconfig
	mpc5200_defconfig
        pseries_defconfig

---
Kevin Hao (4):
  powerpc: enable relocatable support for 6xx
  powerpc: move the exception trampoline helper functions to a separate
    file
  powerpc: s/kdump/exception/ for the exception trampoline functions
  powerpc: make the kernel bootable from non 0 address for 6xx

 arch/powerpc/Kconfig                            |   4 +-
 arch/powerpc/include/asm/exception_trampoline.h |  35 ++++++++
 arch/powerpc/include/asm/kdump.h                |  32 --------
 arch/powerpc/include/asm/page.h                 |   2 +-
 arch/powerpc/kernel/Makefile                    |   1 +
 arch/powerpc/kernel/crash_dump.c                |  41 ----------
 arch/powerpc/kernel/exception_trampoline.c      |  82 +++++++++++++++++++
 arch/powerpc/kernel/head_32.S                   | 103 ++++++++++++++++++++++++
 arch/powerpc/kernel/prom.c                      |   4 +-
 arch/powerpc/kernel/prom_init_check.sh          |   2 +-
 arch/powerpc/kernel/setup_32.c                  |   3 +-
 arch/powerpc/kernel/setup_64.c                  |   4 +-
 arch/powerpc/mm/ppc_mmu_32.c                    |   7 +-
 13 files changed, 232 insertions(+), 88 deletions(-)
 create mode 100644 arch/powerpc/include/asm/exception_trampoline.h
 create mode 100644 arch/powerpc/kernel/exception_trampoline.c

-- 
1.8.1.4


Thanks,
Kevin

[PATCH 1/4] powerpc: enable relocatable support for 6xx

[Kevin Hao]

This is based on the codes in head_44x.S. With this patch the kernel
can only boot from 0 with CONFIG_RELOCATABLE enabled. We will add the
support to boot from a non 0 address in the following patches.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
---
 arch/powerpc/Kconfig                   |   2 +-
 arch/powerpc/include/asm/page.h        |   2 +-
 arch/powerpc/kernel/head_32.S          | 103 +++++++++++++++++++++++++++++++++
 arch/powerpc/kernel/prom_init_check.sh |   2 +-
 4 files changed, 106 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index c33e3ad..8fe2792 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -866,7 +866,7 @@ config DYNAMIC_MEMSTART
 
 config RELOCATABLE
 	bool "Build a relocatable kernel"
-	depends on ADVANCED_OPTIONS && FLATMEM && 44x
+	depends on ADVANCED_OPTIONS && FLATMEM && (44x || 6xx)
 	select NONSTATIC_KERNEL
 	help
 	  This builds a kernel image that is capable of running at the
diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index 988c812..7145c14 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -207,7 +207,7 @@ extern long long virt_phys_offset;
  * On non-Book-E PPC64 PAGE_OFFSET and MEMORY_START are constants so use
  * the other definitions for __va & __pa.
  */
-#ifdef CONFIG_BOOKE
+#if defined(CONFIG_BOOKE) || defined(CONFIG_6xx)
 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + VIRT_PHYS_OFFSET))
 #define __pa(x) ((unsigned long)(x) - VIRT_PHYS_OFFSET)
 #else
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index dc0488b..eb47b13 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -73,6 +73,8 @@ _ENTRY(_start);
 	nop	/* used by __secondary_hold on prep (mtx) and chrp smp */
 	nop
 
+	bl	perform_relocation
+
 /* PMAC
  * Enter here with the kernel text, data and bss loaded starting at
  * 0, running with virtual == physical mapping.
@@ -149,6 +151,8 @@ __start:
  */
 	bl	early_init
 
+	bl	after_relocation_init
+
 /* Switch MMU off, clear BATs and flush TLB. At this point, r3 contains
  * the physical address we are running at, returned by early_init()
  */
@@ -180,6 +184,7 @@ __after_mmu_off:
 #endif /* CONFIG_6xx */
 
 
+#ifndef CONFIG_RELOCATABLE
 /*
  * We need to run with _start at physical address 0.
  * On CHRP, we are loaded at 0x10000 since OF on CHRP uses
@@ -193,6 +198,8 @@ __after_mmu_off:
 	lis	r5,PHYSICAL_START@h
 	cmplw	0,r4,r5			/* already running at PHYSICAL_START? */
 	bne	relocate_kernel
+#endif
+
 /*
  * we now have the 1st 16M of ram mapped with the bats.
  * prep needs the mmu to be turned on here, but pmac already has it on.
@@ -1263,6 +1270,102 @@ m8260_gorom:
 	blr
 #endif
 
+perform_relocation:
+#ifdef CONFIG_RELOCATABLE
+/*
+ * Relocate ourselves to the current runtime address.
+ * This is called only by the Boot CPU.
+ * r21 will be loaded with the physical runtime address of _stext
+ * Save the r3~r7 since these registers may contain the values needed
+ * by the following boot code.
+ */
+	mr	r22,r3
+	mr	r23,r4
+	mr	r24,r5
+	mr	r25,r6
+	mr	r26,r7
+
+	mflr	r20
+	bl	0f				/* Get our runtime address */
+0:	mflr	r21				/* Make it accessible */
+	addis	r21,r21,(_stext - 0b)@ha
+	addi	r21,r21,(_stext - 0b)@l 	/*Get our current runtime base*/
+
+	/*
+	 * We have the runtime address of our base.
+	 * We calculate our shift of offset from a 256M page.
+	 * We could map the 256M page we belong to at PAGE_OFFSET and
+	 * get going from there.
+	 */
+	lis	r4,KERNELBASE@h
+	ori	r4,r4,KERNELBASE@l
+	rlwinm	r6,r21,0,4,31			/* r6 = PHYS_START % 256M */
+	rlwinm	r5,r4,0,4,31			/* r5 = KERNELBASE % 256M */
+	subf	r3,r5,r6			/* r3 = r6 - r5 */
+	add	r3,r4,r3			/* Required Virutal Address */
+
+	bl	relocate
+	mtlr	r20
+	mr	r3,r22
+	mr	r4,r23
+	mr	r5,r24
+	mr	r6,r25
+	mr	r7,r26
+#endif
+	blr
+
+after_relocation_init:
+#ifdef CONFIG_RELOCATABLE
+	/*
+	 * Relocatable kernel support based on processing of dynamic
+	 * relocation entries.
+	 *
+	 * r21 will contain the current offset of _stext
+	 */
+	lis	r3,kernstart_addr@ha
+	la	r3,kernstart_addr@l(r3)
+
+	/* Store kernstart_addr */
+	tophys(r3,r3)
+	stw	r21,0(r3)
+
+	/*
+	 * Compute the virt_phys_offset :
+	 * virt_phys_offset = stext.run - kernstart_addr
+	 *
+	 * stext.run = (KERNELBASE & ~0xfffffff) + (kernstart_addr & 0xfffffff)
+	 * When we relocate, we have :
+	 *
+	 *	(kernstart_addr & 0xfffffff) = (stext.run & 0xfffffff)
+	 *
+	 * hence:
+	 *  virt_phys_offset = (KERNELBASE & ~0xfffffff)
+	 *                            - (kernstart_addr & ~0xfffffff)
+	 *
+	 */
+
+	/* KERNELBASE&~0xfffffff => (r4,r5) */
+	lis	r5,KERNELBASE@h
+	rlwinm	r5,r5,0,0,3	/* Align to 256M, lower 32bit */
+
+	/* kernelstart_addr & ~0xfffffff => (r6,r7) */
+	rlwinm	r7,r21,0,0,3	/* Align to 256M, lower 32bit */
+
+	/*
+	 * 64bit subtraction.
+	 */
+	subf	r5,r7,r5
+
+	/* Store virt_phys_offset */
+	lis	r3,virt_phys_offset@h
+	ori	r3,r3,virt_phys_offset@l
+
+	tophys(r3,r3)
+	li	r4,0
+	stw	r4,0(r3)	/* Higher 32bit */
+	stw	r5,4(r3)	/* Lower 32bit */
+#endif
+	blr
 
 /*
  * We put a few things here that have to be page-aligned.
diff --git a/arch/powerpc/kernel/prom_init_check.sh b/arch/powerpc/kernel/prom_init_check.sh
index 3765da6..a24c208 100644
--- a/arch/powerpc/kernel/prom_init_check.sh
+++ b/arch/powerpc/kernel/prom_init_check.sh
@@ -22,7 +22,7 @@ __secondary_hold_acknowledge __secondary_hold_spinloop __start
 strcmp strcpy strlcpy strlen strncmp strstr logo_linux_clut224
 reloc_got2 kernstart_addr memstart_addr linux_banner _stext
 opal_query_takeover opal_do_takeover opal_enter_rtas opal_secondary_entry
-boot_command_line __prom_init_toc_start __prom_init_toc_end"
+boot_command_line __prom_init_toc_start __prom_init_toc_end virt_phys_offset"
 
 NM="$1"
 OBJ="$2"
-- 
1.8.1.4

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

[Kevin Hao]

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

[PATCH 3/4] powerpc: s/kdump/exception/ for the exception trampoline functions

[Kevin Hao]

These functions are not just kdump specific. Replace the 'kdump' with
the 'exception' to make them more general.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
---
 arch/powerpc/include/asm/exception_trampoline.h | 20 ++++++++++----------
 arch/powerpc/kernel/exception_trampoline.c      | 14 +++++++-------
 arch/powerpc/kernel/prom.c                      |  2 +-
 arch/powerpc/kernel/setup_32.c                  |  2 +-
 arch/powerpc/kernel/setup_64.c                  |  2 +-
 5 files changed, 20 insertions(+), 20 deletions(-)

diff --git a/arch/powerpc/include/asm/exception_trampoline.h b/arch/powerpc/include/asm/exception_trampoline.h
index 707ad6c..88281c9 100644
--- a/arch/powerpc/include/asm/exception_trampoline.h
+++ b/arch/powerpc/include/asm/exception_trampoline.h
@@ -1,10 +1,10 @@
 #ifndef _EXCEPTION_TRAMPOLINE_H
 #define _EXCEPTION_TRAMPOLINE_H
 
-/* How many bytes to reserve at zero for kdump. The reserve limit should
+/* How many bytes to reserve at zero for exception. 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 */
+#define EXCEPTION_RESERVE_LIMIT	0x10000 /* 64K */
 
 /*
  * On PPC64 translation is disabled during trampoline setup, so we use
@@ -13,22 +13,22 @@
  * 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
+#define EXCEPTION_TRAMPOLINE_START	0x0100
+#define EXCEPTION_TRAMPOLINE_END	0x3000
 #else
-#define KDUMP_TRAMPOLINE_START	(0x0100 + PAGE_OFFSET)
-#define KDUMP_TRAMPOLINE_END	(0x3000 + PAGE_OFFSET)
+#define EXCEPTION_TRAMPOLINE_START	(0x0100 + PAGE_OFFSET)
+#define EXCEPTION_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);
+extern void reserve_exception_trampoline(void);
+extern void setup_exception_trampoline(void);
 #else
 /* !CRASH_DUMP || !NONSTATIC_KERNEL */
-static inline void reserve_kdump_trampoline(void) { ; }
-static inline void setup_kdump_trampoline(void) { ; }
+static inline void reserve_exception_trampoline(void) { ; }
+static inline void setup_exception_trampoline(void) { ; }
 #endif
 
 #endif /* __ASSEMBLY__ */
diff --git a/arch/powerpc/kernel/exception_trampoline.c b/arch/powerpc/kernel/exception_trampoline.c
index 71f4b72..b725116 100644
--- a/arch/powerpc/kernel/exception_trampoline.c
+++ b/arch/powerpc/kernel/exception_trampoline.c
@@ -15,7 +15,7 @@
 #include <linux/bootmem.h>
 #include <linux/memblock.h>
 #include <asm/code-patching.h>
-#include <asm/kdump.h>
+#include <asm/exception_trampoline.h>
 #include <asm/prom.h>
 #include <asm/firmware.h>
 #include <asm/uaccess.h>
@@ -29,9 +29,9 @@
 #endif
 
 #ifndef CONFIG_NONSTATIC_KERNEL
-void __init reserve_kdump_trampoline(void)
+void __init reserve_exception_trampoline(void)
 {
-	memblock_reserve(0, KDUMP_RESERVE_LIMIT);
+	memblock_reserve(0, EXCEPTION_RESERVE_LIMIT);
 }
 
 static void __init create_trampoline(unsigned long addr)
@@ -50,13 +50,13 @@ static void __init create_trampoline(unsigned long addr)
 	patch_branch(++p, addr + PHYSICAL_START, 0);
 }
 
-void __init setup_kdump_trampoline(void)
+void __init setup_exception_trampoline(void)
 {
 	unsigned long i;
 
-	DBG(" -> setup_kdump_trampoline()\n");
+	DBG(" -> setup_exception_trampoline()\n");
 
-	for (i = KDUMP_TRAMPOLINE_START; i < KDUMP_TRAMPOLINE_END; i += 8) {
+	for (i = EXCEPTION_TRAMPOLINE_START; i < EXCEPTION_TRAMPOLINE_END; i += 8) {
 		create_trampoline(i);
 	}
 
@@ -65,6 +65,6 @@ void __init setup_kdump_trampoline(void)
 	create_trampoline(__pa(machine_check_fwnmi) - PHYSICAL_START);
 #endif /* CONFIG_PPC_PSERIES */
 
-	DBG(" <- setup_kdump_trampoline()\n");
+	DBG(" <- setup_exception_trampoline()\n");
 }
 #endif /* CONFIG_NONSTATIC_KERNEL */
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 4a13ac5..57214ee 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -669,7 +669,7 @@ void __init early_init_devtree(void *params)
 	/* If relocatable, reserve first 32k for interrupt vectors etc. */
 	if (PHYSICAL_START > MEMORY_START)
 		memblock_reserve(MEMORY_START, 0x8000);
-	reserve_kdump_trampoline();
+	reserve_exception_trampoline();
 #ifdef CONFIG_FA_DUMP
 	/*
 	 * If we fail to reserve memory for firmware-assisted dump then
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index 9f3aa43..e040bb2 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -133,7 +133,7 @@ notrace void __init machine_init(u64 dt_ptr)
 
 	probe_machine();
 
-	setup_kdump_trampoline();
+	setup_exception_trampoline();
 
 #ifdef CONFIG_6xx
 	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 06b8562..b077847 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -222,7 +222,7 @@ void __init early_setup(unsigned long dt_ptr)
 	/* Probe the machine type */
 	probe_machine();
 
-	setup_kdump_trampoline();
+	setup_exception_trampoline();
 
 	DBG("Found, Initializing memory management...\n");
 
-- 
1.8.1.4

[PATCH 4/4] powerpc: make the kernel bootable from non 0 address for 6xx

[Kevin Hao]

Add the support to boot the kernel from a non 0 address for 6xx.
Setup the exception trampoline if the physical start address is
not 0.

For a kdump kernel, enable the relocatable support implicitly.
Since the memstart_adddr of the kdump is not 0, we definitely
should regard this when setting up the BAT map.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
---
 arch/powerpc/Kconfig                            |  2 +-
 arch/powerpc/include/asm/exception_trampoline.h |  4 ++--
 arch/powerpc/kernel/Makefile                    |  3 ++-
 arch/powerpc/kernel/exception_trampoline.c      | 18 +++++++++++++++---
 arch/powerpc/mm/ppc_mmu_32.c                    |  7 +------
 5 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 8fe2792..6e03028 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -382,7 +382,7 @@ config KEXEC
 config CRASH_DUMP
 	bool "Build a kdump crash kernel"
 	depends on PPC64 || 6xx || FSL_BOOKE || (44x && !SMP)
-	select RELOCATABLE if PPC64 || 44x
+	select RELOCATABLE if PPC64 || 44x || 6xx
 	select DYNAMIC_MEMSTART if FSL_BOOKE
 	help
 	  Build a kernel suitable for use as a kdump capture kernel.
diff --git a/arch/powerpc/include/asm/exception_trampoline.h b/arch/powerpc/include/asm/exception_trampoline.h
index 88281c9..df4af6a 100644
--- a/arch/powerpc/include/asm/exception_trampoline.h
+++ b/arch/powerpc/include/asm/exception_trampoline.h
@@ -22,11 +22,11 @@
 
 #ifndef __ASSEMBLY__
 
-#if defined(CONFIG_CRASH_DUMP) && !defined(CONFIG_NONSTATIC_KERNEL)
+#if  defined(CONFIG_RELOCATABLE) && defined(CONFIG_6xx)
 extern void reserve_exception_trampoline(void);
 extern void setup_exception_trampoline(void);
 #else
-/* !CRASH_DUMP || !NONSTATIC_KERNEL */
+/* !CONFIG_RELOCATABLE || !CONFIG_6xx */
 static inline void reserve_exception_trampoline(void) { ; }
 static inline void setup_exception_trampoline(void) { ; }
 #endif
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index c73a0e3..c722156 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -59,7 +59,8 @@ obj-$(CONFIG_LPARCFG)		+= lparcfg.o
 obj-$(CONFIG_IBMVIO)		+= vio.o
 obj-$(CONFIG_IBMEBUS)           += ibmebus.o
 obj-$(CONFIG_GENERIC_TBSYNC)	+= smp-tbsync.o
-obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o exception_trampoline.o
+obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
+obj-$(CONFIG_RELOCATABLE)	+= exception_trampoline.o
 obj-$(CONFIG_FA_DUMP)		+= fadump.o
 ifeq ($(CONFIG_PPC32),y)
 obj-$(CONFIG_E500)		+= idle_e500.o
diff --git a/arch/powerpc/kernel/exception_trampoline.c b/arch/powerpc/kernel/exception_trampoline.c
index b725116..68aed9e 100644
--- a/arch/powerpc/kernel/exception_trampoline.c
+++ b/arch/powerpc/kernel/exception_trampoline.c
@@ -28,10 +28,16 @@
 #define DBG(fmt...)
 #endif
 
-#ifndef CONFIG_NONSTATIC_KERNEL
+#ifdef CONFIG_6xx
 void __init reserve_exception_trampoline(void)
 {
-	memblock_reserve(0, EXCEPTION_RESERVE_LIMIT);
+	/*
+	 * We don't need to reserve this memory region for a kdump kernel
+	 * since this is not included in the memory regions of kdump kernel.
+	 */
+
+	if (!memstart_addr && PHYSICAL_START)
+		memblock_reserve(0, EXCEPTION_RESERVE_LIMIT);
 }
 
 static void __init create_trampoline(unsigned long addr)
@@ -54,6 +60,12 @@ void __init setup_exception_trampoline(void)
 {
 	unsigned long i;
 
+	if (!PHYSICAL_START)
+		return;
+
+	if (PHYSICAL_START > 0x2000000)
+		panic("Don't support to load a kernel above 32M address");
+
 	DBG(" -> setup_exception_trampoline()\n");
 
 	for (i = EXCEPTION_TRAMPOLINE_START; i < EXCEPTION_TRAMPOLINE_END; i += 8) {
@@ -67,4 +79,4 @@ void __init setup_exception_trampoline(void)
 
 	DBG(" <- setup_exception_trampoline()\n");
 }
-#endif /* CONFIG_NONSTATIC_KERNEL */
+#endif /* CONFIG_6xx */
diff --git a/arch/powerpc/mm/ppc_mmu_32.c b/arch/powerpc/mm/ppc_mmu_32.c
index 11571e1..99ce477 100644
--- a/arch/powerpc/mm/ppc_mmu_32.c
+++ b/arch/powerpc/mm/ppc_mmu_32.c
@@ -86,7 +86,7 @@ unsigned long __init mmu_mapin_ram(unsigned long top)
 
 	/* Make sure we don't map a block larger than the
 	   smallest alignment of the physical address. */
-	tot = top;
+	tot = top + memstart_addr;
 	for (bl = 128<<10; bl < max_size; bl <<= 1) {
 		if (bl * 2 > tot)
 			break;
@@ -275,11 +275,6 @@ void __init MMU_init_hw(void)
 void setup_initial_memory_limit(phys_addr_t first_memblock_base,
 				phys_addr_t first_memblock_size)
 {
-	/* We don't currently support the first MEMBLOCK not mapping 0
-	 * physical on those processors
-	 */
-	BUG_ON(first_memblock_base != 0);
-
 	/* 601 can only access 16MB at the moment */
 	if (PVR_VER(mfspr(SPRN_PVR)) == 1)
 		memblock_set_current_limit(min_t(u64, first_memblock_size, 0x01000000));
-- 
1.8.1.4