11 files changed, 135 insertions, 22 deletions

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 4bb2e9310a56..fdc755a05f70 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -656,21 +656,76 @@ config LOWMEM_SIZE
         hex "Maximum low memory size (in bytes)" if LOWMEM_SIZE_BOOL
         default "0x30000000"
 
+config RELOCATABLE
+        bool "Build a relocatable kernel (EXPERIMENTAL)"
+        depends on EXPERIMENTAL && ADVANCED_OPTIONS && FLATMEM && FSL_BOOKE
+        help
+          This builds a kernel image that is capable of running at the
+          location the kernel is loaded at (some alignment restrictions may
+          exist).
+
+          One use is for the kexec on panic case where the recovery kernel
+          must live at a different physical address than the primary
+          kernel.
+
+          Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
+          it has been loaded at and the compile time physical addresses
+          CONFIG_PHYSICAL_START is ignored.  However CONFIG_PHYSICAL_START
+          setting can still be useful to bootwrappers that need to know the
+          load location of the kernel (eg. u-boot/mkimage).
+
+config PAGE_OFFSET_BOOL
+        bool "Set custom page offset address"
+        depends on ADVANCED_OPTIONS
+        help
+          This option allows you to set the kernel virtual address at which
+          the kernel will map low memory.  This can be useful in optimizing
+          the virtual memory layout of the system.
+
+          Say N here unless you know what you are doing.
+
+config PAGE_OFFSET
+        hex "Virtual address of memory base" if PAGE_OFFSET_BOOL
+        default "0xc0000000"
+
 config KERNEL_START_BOOL
         bool "Set custom kernel base address"
         depends on ADVANCED_OPTIONS
         help
           This option allows you to set the kernel virtual address at which
-          the kernel will map low memory (the kernel image will be linked at
-          this address).  This can be useful in optimizing the virtual memory
-          layout of the system.
+          the kernel will be loaded.  Normally this should match PAGE_OFFSET
+          however there are times (like kdump) that one might not want them
+          to be the same.
 
           Say N here unless you know what you are doing.
 
 config KERNEL_START
         hex "Virtual address of kernel base" if KERNEL_START_BOOL
+        default PAGE_OFFSET if PAGE_OFFSET_BOOL
+        default "0xc2000000" if CRASH_DUMP
         default "0xc0000000"
 
+config PHYSICAL_START_BOOL
+        bool "Set physical address where the kernel is loaded"
+        depends on ADVANCED_OPTIONS && FLATMEM && FSL_BOOKE
+        help
+          This gives the physical address where the kernel is loaded.
+
+          Say N here unless you know what you are doing.
+
+config PHYSICAL_START
+        hex "Physical address where the kernel is loaded" if PHYSICAL_START_BOOL
+        default "0x02000000" if PPC_STD_MMU && CRASH_DUMP
+        default "0x00000000"
+
+config PHYSICAL_ALIGN
+        hex
+        default "0x10000000" if FSL_BOOKE
+        help
+          This value puts the alignment restrictions on physical address
+          where kernel is loaded and run from. Kernel is compiled for an
+          address which meets above alignment restriction.
+
 config TASK_SIZE_BOOL
         bool "Set custom user task size"
         depends on ADVANCED_OPTIONS
@@ -717,9 +772,17 @@ config PIN_TLB
 endmenu
 
 if PPC64
+config PAGE_OFFSET
+        hex
+        default "0xc000000000000000"
 config KERNEL_START
         hex
+        default "0xc000000002000000" if CRASH_DUMP
         default "0xc000000000000000"
+config PHYSICAL_START
+        hex
+        default "0x02000000" if CRASH_DUMP
+        default "0x00000000"
 endif
 
 source "net/Kconfig"
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 4ff744143566..e581524d85bc 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -371,6 +371,17 @@ skpinv:	addi	r6,r6,1				/* Increment */
 
         bl      early_init
 
+#ifdef CONFIG_RELOCATABLE
+        lis     r3,kernstart_addr@ha
+        la      r3,kernstart_addr@l(r3)
+#ifdef CONFIG_PHYS_64BIT
+        stw     r23,0(r3)
+        stw     r25,4(r3)
+#else
+        stw     r25,0(r3)
+#endif
+#endif
+
         mfspr   r3,SPRN_TLB1CFG
         andi.   r3,r3,0xfff
         lis     r4,num_tlbcam_entries@ha
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 3bfe7837e820..2aefe2a4129a 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -53,6 +53,7 @@
 #include <asm/pci-bridge.h>
 #include <asm/phyp_dump.h>
 #include <asm/kexec.h>
+#include <mm/mmu_decl.h>
 
 #ifdef DEBUG
 #define DBG(fmt...) printk(KERN_ERR fmt)
@@ -978,7 +979,10 @@ static int __init early_init_dt_scan_memory(unsigned long node,
                 }
 #endif
                 lmb_add(base, size);
+
+                memstart_addr = min((u64)memstart_addr, base);
         }
+
         return 0;
 }
 
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 31ada9fdfc5c..153a48dc8f40 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -435,7 +435,7 @@ void __init setup_system(void)
                 printk("htab_address                  = 0x%p\n", htab_address);
         printk("htab_hash_mask                = 0x%lx\n", htab_hash_mask);
 #if PHYSICAL_START > 0
-        printk("physical_start                = 0x%x\n", PHYSICAL_START);
+        printk("physical_start                = 0x%lx\n", PHYSICAL_START);
 #endif
         printk("-----------------------------------------------------\n");
 
diff --git a/arch/powerpc/mm/fsl_booke_mmu.c b/arch/powerpc/mm/fsl_booke_mmu.c
index ada249bf9779..ce10e2b1b902 100644
--- a/arch/powerpc/mm/fsl_booke_mmu.c
+++ b/arch/powerpc/mm/fsl_booke_mmu.c
@@ -202,7 +202,7 @@ adjust_total_lowmem(void)
                 cam_max_size = max_lowmem_size;
 
         /* adjust lowmem size to max_lowmem_size */
-        ram = min(max_lowmem_size, total_lowmem);
+        ram = min(max_lowmem_size, (phys_addr_t)total_lowmem);
 
         /* Calculate CAM values */
         __cam0 = 1UL << 2 * (__ilog2(ram) / 2);
diff --git a/arch/powerpc/mm/init_32.c b/arch/powerpc/mm/init_32.c
index 47325f23c51f..578750e4ca88 100644
--- a/arch/powerpc/mm/init_32.c
+++ b/arch/powerpc/mm/init_32.c
@@ -59,7 +59,10 @@ DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
 unsigned long total_memory;
 unsigned long total_lowmem;
 
-phys_addr_t memstart_addr;
+phys_addr_t memstart_addr = (phys_addr_t)~0ull;
+EXPORT_SYMBOL(memstart_addr);
+phys_addr_t kernstart_addr;
+EXPORT_SYMBOL(kernstart_addr);
 phys_addr_t lowmem_end_addr;
 
 int boot_mapsize;
diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c
index 698bd000f98b..c5ac532a0161 100644
--- a/arch/powerpc/mm/init_64.c
+++ b/arch/powerpc/mm/init_64.c
@@ -72,7 +72,8 @@
 #warning TASK_SIZE is smaller than it needs to be.
 #endif
 
-phys_addr_t memstart_addr;
+phys_addr_t memstart_addr = ~0;
+phys_addr_t kernstart_addr;
 
 void free_initmem(void)
 {
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 16def4dcff6d..0062e6b1c555 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -216,7 +216,7 @@ void __init do_init_bootmem(void)
         unsigned long total_pages;
         int boot_mapsize;
 
-        max_pfn = lmb_end_of_DRAM() >> PAGE_SHIFT;
+        max_low_pfn = max_pfn = lmb_end_of_DRAM() >> PAGE_SHIFT;
         total_pages = (lmb_end_of_DRAM() - memstart_addr) >> PAGE_SHIFT;
 #ifdef CONFIG_HIGHMEM
         total_pages = total_lowmem >> PAGE_SHIFT;
@@ -232,7 +232,8 @@ void __init do_init_bootmem(void)
 
         start = lmb_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);
 
-        boot_mapsize = init_bootmem(start >> PAGE_SHIFT, total_pages);
+        min_low_pfn = MEMORY_START >> PAGE_SHIFT;
+        boot_mapsize = init_bootmem_node(NODE_DATA(0), start >> PAGE_SHIFT, min_low_pfn, max_low_pfn);
 
         /* Add active regions with valid PFNs */
         for (i = 0; i < lmb.memory.cnt; i++) {
diff --git a/include/asm-powerpc/kdump.h b/include/asm-powerpc/kdump.h
index 10e8eb1e6f4f..f6c93c716898 100644
--- a/include/asm-powerpc/kdump.h
+++ b/include/asm-powerpc/kdump.h
@@ -11,16 +11,11 @@
 
 #ifdef CONFIG_CRASH_DUMP
 
-#define PHYSICAL_START  KDUMP_KERNELBASE
 #define KDUMP_TRAMPOLINE_START  0x0100
 #define KDUMP_TRAMPOLINE_END    0x3000
 
 #define KDUMP_MIN_TCE_ENTRIES   2048
 
-#else /* !CONFIG_CRASH_DUMP */
-
-#define PHYSICAL_START  0x0
-
 #endif /* CONFIG_CRASH_DUMP */
 
 #ifndef __ASSEMBLY__
diff --git a/include/asm-powerpc/page.h b/include/asm-powerpc/page.h
index 6c850609b847..cffdf0eb0df6 100644
--- a/include/asm-powerpc/page.h
+++ b/include/asm-powerpc/page.h
@@ -12,6 +12,7 @@
 
 #include <asm/asm-compat.h>
 #include <asm/kdump.h>
+#include <asm/types.h>
 
 /*
  * On PPC32 page size is 4K. For PPC64 we support either 4K or 64K software
@@ -42,8 +43,23 @@
  *
  * The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET.
  *
- * To get a physical address from a virtual one you subtract PAGE_OFFSET,
- * _not_ KERNELBASE.
+ * PAGE_OFFSET is the virtual address of the start of lowmem.
+ *
+ * PHYSICAL_START is the physical address of the start of the kernel.
+ *
+ * MEMORY_START is the physical address of the start of lowmem.
+ *
+ * KERNELBASE, PAGE_OFFSET, and PHYSICAL_START are all configurable on
+ * ppc32 and based on how they are set we determine MEMORY_START.
+ *
+ * For the linear mapping the following equation should be true:
+ * KERNELBASE - PAGE_OFFSET = PHYSICAL_START - MEMORY_START
+ *
+ * Also, KERNELBASE >= PAGE_OFFSET and PHYSICAL_START >= MEMORY_START
+ *
+ * There are two was to determine a physical address from a virtual one:
+ * va = pa + PAGE_OFFSET - MEMORY_START
+ * va = pa + KERNELBASE - PHYSICAL_START
  *
  * If you want to know something's offset from the start of the kernel you
  * should subtract KERNELBASE.
@@ -51,20 +67,33 @@
  * If you want to test if something's a kernel address, use is_kernel_addr().
  */
 
-#define PAGE_OFFSET     ASM_CONST(CONFIG_KERNEL_START)
-#define KERNELBASE      (PAGE_OFFSET + PHYSICAL_START)
-#define LOAD_OFFSET     PAGE_OFFSET
+#define KERNELBASE      ASM_CONST(CONFIG_KERNEL_START)
+#define PAGE_OFFSET     ASM_CONST(CONFIG_PAGE_OFFSET)
+#define LOAD_OFFSET     ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START))
+
+#if defined(CONFIG_RELOCATABLE) && defined(CONFIG_FLATMEM)
+#ifndef __ASSEMBLY__
+extern phys_addr_t memstart_addr;
+extern phys_addr_t kernstart_addr;
+#endif
+#define PHYSICAL_START  kernstart_addr
+#define MEMORY_START    memstart_addr
+#else
+#define PHYSICAL_START  ASM_CONST(CONFIG_PHYSICAL_START)
+#define MEMORY_START    (PHYSICAL_START + PAGE_OFFSET - KERNELBASE)
+#endif
 
 #ifdef CONFIG_FLATMEM
-#define pfn_valid(pfn)          ((pfn) < max_mapnr)
+#define ARCH_PFN_OFFSET         (MEMORY_START >> PAGE_SHIFT)
+#define pfn_valid(pfn)          ((pfn) >= ARCH_PFN_OFFSET && (pfn) < (ARCH_PFN_OFFSET + max_mapnr))
 #endif
 
 #define virt_to_page(kaddr)     pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
 #define pfn_to_kaddr(pfn)       __va((pfn) << PAGE_SHIFT)
 #define virt_addr_valid(kaddr)  pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
 
-#define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET))
-#define __pa(x) ((unsigned long)(x) - PAGE_OFFSET)
+#define __va(x) ((void *)((unsigned long)(x) - PHYSICAL_START + KERNELBASE))
+#define __pa(x) ((unsigned long)(x) + PHYSICAL_START - KERNELBASE)
 
 /*
  * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI,
diff --git a/include/asm-powerpc/page_32.h b/include/asm-powerpc/page_32.h
index 51f8134b5939..ebfae530a379 100644
--- a/include/asm-powerpc/page_32.h
+++ b/include/asm-powerpc/page_32.h
@@ -1,6 +1,12 @@
 #ifndef _ASM_POWERPC_PAGE_32_H
 #define _ASM_POWERPC_PAGE_32_H
 
+#if defined(CONFIG_PHYSICAL_ALIGN) && (CONFIG_PHYSICAL_START != 0)
+#if (CONFIG_PHYSICAL_START % CONFIG_PHYSICAL_ALIGN) != 0
+#error "CONFIG_PHYSICAL_START must be a multiple of CONFIG_PHYSICAL_ALIGN"
+#endif
+#endif
+
 #define VM_DATA_DEFAULT_FLAGS   VM_DATA_DEFAULT_FLAGS32
 
 #ifdef CONFIG_NOT_COHERENT_CACHE