10 files changed, 110 insertions, 63 deletions

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 369d93e7377c..5b1527883fcb 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -323,13 +323,11 @@ config KEXEC
 
 config CRASH_DUMP
         bool "Build a kdump crash kernel"
-        depends on PPC_MULTIPLATFORM && PPC64
+        depends on PPC_MULTIPLATFORM && PPC64 && RELOCATABLE
         help
           Build a kernel suitable for use as a kdump capture kernel.
-          The kernel will be linked at a different address than normal, and
-          so can only be used for Kdump.
-
-          Don't change this unless you know what you are doing.
+          The same kernel binary can be used as production kernel and dump
+          capture kernel.
 
 config PHYP_DUMP
         bool "Hypervisor-assisted dump (EXPERIMENTAL)"
@@ -829,11 +827,9 @@ config PAGE_OFFSET
         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
 
diff --git a/arch/powerpc/include/asm/kdump.h b/arch/powerpc/include/asm/kdump.h
index f6c93c716898..a503da9d56f3 100644
--- a/arch/powerpc/include/asm/kdump.h
+++ b/arch/powerpc/include/asm/kdump.h
@@ -9,6 +9,12 @@
  * Reserve to the end of the FWNMI area, see head_64.S */
 #define KDUMP_RESERVE_LIMIT     0x10000 /* 64K */
 
+/*
+ * Used to differentiate between relocatable kdump kernel and other
+ * kernels
+ */
+#define KDUMP_SIGNATURE 0xfeed1234
+
 #ifdef CONFIG_CRASH_DUMP
 
 #define KDUMP_TRAMPOLINE_START  0x0100
@@ -19,17 +25,18 @@
 #endif /* CONFIG_CRASH_DUMP */
 
 #ifndef __ASSEMBLY__
-#ifdef CONFIG_CRASH_DUMP
 
+extern unsigned long __kdump_flag;
+
+#if defined(CONFIG_CRASH_DUMP) && !defined(CONFIG_RELOCATABLE)
 extern void reserve_kdump_trampoline(void);
 extern void setup_kdump_trampoline(void);
-
-#else /* !CONFIG_CRASH_DUMP */
-
+#else
+/* !CRASH_DUMP || RELOCATABLE */
 static inline void reserve_kdump_trampoline(void) { ; }
 static inline void setup_kdump_trampoline(void) { ; }
+#endif
 
-#endif /* CONFIG_CRASH_DUMP */
 #endif /* __ASSEMBLY__ */
 
 #endif /* __PPC64_KDUMP_H */
diff --git a/arch/powerpc/kernel/crash_dump.c b/arch/powerpc/kernel/crash_dump.c
index 97e056379728..19671aca6591 100644
--- a/arch/powerpc/kernel/crash_dump.c
+++ b/arch/powerpc/kernel/crash_dump.c
@@ -30,6 +30,7 @@
 /* Stores the physical address of elf header of crash image. */
 unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
 
+#ifndef CONFIG_RELOCATABLE
 void __init reserve_kdump_trampoline(void)
 {
         lmb_reserve(0, KDUMP_RESERVE_LIMIT);
@@ -68,6 +69,7 @@ void __init setup_kdump_trampoline(void)
 
         DBG(" <- setup_kdump_trampoline()\n");
 }
+#endif /* CONFIG_RELOCATABLE */
 
 /*
  * Note: elfcorehdr_addr is not just limited to vmcore. It is also used by
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 84856bee33a5..69489bd3210c 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -97,6 +97,12 @@ __secondary_hold_spinloop:
 __secondary_hold_acknowledge:
         .llong  0x0
 
+        /* This flag is set by purgatory if we should be a kdump kernel. */
+        /* Do not move this variable as purgatory knows about it. */
+        .globl  __kdump_flag
+__kdump_flag:
+        .llong  0x0
+
 #ifdef CONFIG_PPC_ISERIES
         /*
          * At offset 0x20, there is a pointer to iSeries LPAR data.
@@ -1384,7 +1390,13 @@ _STATIC(__after_prom_start)
         /* process relocations for the final address of the kernel */
         lis     r25,PAGE_OFFSET@highest /* compute virtual base of kernel */
         sldi    r25,r25,32
-        mr      r3,r25
+#ifdef CONFIG_CRASH_DUMP
+        ld      r7,__kdump_flag-_stext(r26)
+        cmpldi  cr0,r7,1        /* kdump kernel ? - stay where we are */
+        bne     1f
+        add     r25,r25,r26
+#endif
+1:      mr      r3,r25
         bl      .relocate
 #endif
 
@@ -1398,11 +1410,26 @@ _STATIC(__after_prom_start)
         li      r3,0                    /* target addr */
         mr.     r4,r26                  /* In some cases the loader may  */
         beq     9f                      /* have already put us at zero */
-        lis     r5,(copy_to_here - _stext)@ha
-        addi    r5,r5,(copy_to_here - _stext)@l /* # bytes of memory to copy */
         li      r6,0x100                /* Start offset, the first 0x100 */
                                         /* bytes were copied earlier.    */
 
+#ifdef CONFIG_CRASH_DUMP
+/*
+ * Check if the kernel has to be running as relocatable kernel based on the
+ * variable __kdump_flag, if it is set the kernel is treated as relocatable
+ * kernel, otherwise it will be moved to PHYSICAL_START
+ */
+        ld      r7,__kdump_flag-_stext(r26)
+        cmpldi  cr0,r7,1
+        bne     3f
+
+        li      r5,__end_interrupts - _stext    /* just copy interrupts */
+        b       5f
+3:
+#endif
+        lis     r5,(copy_to_here - _stext)@ha
+        addi    r5,r5,(copy_to_here - _stext)@l /* # bytes of memory to copy */
+
         bl      .copy_and_flush         /* copy the first n bytes        */
                                         /* this includes the code being  */
                                         /* executed here.                */
@@ -1411,15 +1438,15 @@ _STATIC(__after_prom_start)
         mtctr   r8
         bctr
 
+p_end:  .llong  _end - _stext
+
 4:      /* Now copy the rest of the kernel up to _end */
         addis   r5,r26,(p_end - _stext)@ha
         ld      r5,(p_end - _stext)@l(r5)       /* get _end */
-        bl      .copy_and_flush         /* copy the rest */
+5:      bl      .copy_and_flush         /* copy the rest */
 
 9:      b       .start_here_multiplatform
 
-p_end:  .llong  _end - _stext
-
 /*
  * Copy routine used to copy the kernel to start at physical address 0
  * and flush and invalidate the caches as needed.
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index ea1ba89f9c90..3857d7e2af0c 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -458,6 +458,42 @@ void iommu_unmap_sg(struct iommu_table *tbl, struct scatterlist *sglist,
         spin_unlock_irqrestore(&(tbl->it_lock), flags);
 }
 
+static void iommu_table_clear(struct iommu_table *tbl)
+{
+        if (!__kdump_flag) {
+                /* Clear the table in case firmware left allocations in it */
+                ppc_md.tce_free(tbl, tbl->it_offset, tbl->it_size);
+                return;
+        }
+
+#ifdef CONFIG_CRASH_DUMP
+        if (ppc_md.tce_get) {
+                unsigned long index, tceval, tcecount = 0;
+
+                /* Reserve the existing mappings left by the first kernel. */
+                for (index = 0; index < tbl->it_size; index++) {
+                        tceval = ppc_md.tce_get(tbl, index + tbl->it_offset);
+                        /*
+                         * Freed TCE entry contains 0x7fffffffffffffff on JS20
+                         */
+                        if (tceval && (tceval != 0x7fffffffffffffffUL)) {
+                                __set_bit(index, tbl->it_map);
+                                tcecount++;
+                        }
+                }
+
+                if ((tbl->it_size - tcecount) < KDUMP_MIN_TCE_ENTRIES) {
+                        printk(KERN_WARNING "TCE table is full; freeing ");
+                        printk(KERN_WARNING "%d entries for the kdump boot\n",
+                                KDUMP_MIN_TCE_ENTRIES);
+                        for (index = tbl->it_size - KDUMP_MIN_TCE_ENTRIES;
+                                index < tbl->it_size; index++)
+                                __clear_bit(index, tbl->it_map);
+                }
+        }
+#endif
+}
+
 /*
  * Build a iommu_table structure.  This contains a bit map which
  * is used to manage allocation of the tce space.
@@ -484,38 +520,7 @@ struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid)
         tbl->it_largehint = tbl->it_halfpoint;
         spin_lock_init(&tbl->it_lock);
 
-#ifdef CONFIG_CRASH_DUMP
-        if (ppc_md.tce_get) {
-                unsigned long index;
-                unsigned long tceval;
-                unsigned long tcecount = 0;
-
-                /*
-                 * Reserve the existing mappings left by the first kernel.
-                 */
-                for (index = 0; index < tbl->it_size; index++) {
-                        tceval = ppc_md.tce_get(tbl, index + tbl->it_offset);
-                        /*
-                         * Freed TCE entry contains 0x7fffffffffffffff on JS20
-                         */
-                        if (tceval && (tceval != 0x7fffffffffffffffUL)) {
-                                __set_bit(index, tbl->it_map);
-                                tcecount++;
-                        }
-                }
-                if ((tbl->it_size - tcecount) < KDUMP_MIN_TCE_ENTRIES) {
-                        printk(KERN_WARNING "TCE table is full; ");
-                        printk(KERN_WARNING "freeing %d entries for the kdump boot\n",
-                                KDUMP_MIN_TCE_ENTRIES);
-                        for (index = tbl->it_size - KDUMP_MIN_TCE_ENTRIES;
-                                index < tbl->it_size; index++)
-                                __clear_bit(index, tbl->it_map);
-                }
-        }
-#else
-        /* Clear the hardware table in case firmware left allocations in it */
-        ppc_md.tce_free(tbl, tbl->it_offset, tbl->it_size);
-#endif
+        iommu_table_clear(tbl);
 
         if (!welcomed) {
                 printk(KERN_INFO "IOMMU table initialized, virtual merging %s\n",
diff --git a/arch/powerpc/kernel/machine_kexec.c b/arch/powerpc/kernel/machine_kexec.c
index aab76887a842..ac2a21f45c75 100644
--- a/arch/powerpc/kernel/machine_kexec.c
+++ b/arch/powerpc/kernel/machine_kexec.c
@@ -88,11 +88,13 @@ void __init reserve_crashkernel(void)
 
         crash_size = crashk_res.end - crashk_res.start + 1;
 
+#ifndef CONFIG_RELOCATABLE
         if (crashk_res.start != KDUMP_KERNELBASE)
                 printk("Crash kernel location must be 0x%x\n",
                                 KDUMP_KERNELBASE);
 
         crashk_res.start = KDUMP_KERNELBASE;
+#endif
         crash_size = PAGE_ALIGN(crash_size);
         crashk_res.end = crashk_res.start + crash_size - 1;
 
diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
index 4bd8b4f5e70d..e6efec788c4d 100644
--- a/arch/powerpc/kernel/machine_kexec_64.c
+++ b/arch/powerpc/kernel/machine_kexec_64.c
@@ -255,11 +255,14 @@ static union thread_union kexec_stack
 /* Our assembly helper, in kexec_stub.S */
 extern NORET_TYPE void kexec_sequence(void *newstack, unsigned long start,
                                         void *image, void *control,
-                                        void (*clear_all)(void)) ATTRIB_NORET;
+                                        void (*clear_all)(void),
+                                        unsigned long kdump_flag) ATTRIB_NORET;
 
 /* too late to fail here */
 void default_machine_kexec(struct kimage *image)
 {
+        unsigned long kdump_flag = 0;
+
         /* prepare control code if any */
 
         /*
@@ -270,8 +273,10 @@ void default_machine_kexec(struct kimage *image)
         * using debugger IPI.
         */
 
-       if (crashing_cpu == -1)
-               kexec_prepare_cpus();
+        if (crashing_cpu == -1)
+                kexec_prepare_cpus();
+        else
+                kdump_flag = KDUMP_SIGNATURE;
 
         /* switch to a staticly allocated stack.  Based on irq stack code.
          * XXX: the task struct will likely be invalid once we do the copy!
@@ -284,7 +289,7 @@ void default_machine_kexec(struct kimage *image)
          */
         kexec_sequence(&kexec_stack, image->start, image,
                         page_address(image->control_code_page),
-                        ppc_md.hpte_clear_all);
+                        ppc_md.hpte_clear_all, kdump_flag);
         /* NOTREACHED */
 }
 
diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index 3053fe5c62f2..a243fd072a77 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -611,10 +611,12 @@ real_mode:	/* assume normal blr return */
 
 
 /*
- * kexec_sequence(newstack, start, image, control, clear_all())
+ * kexec_sequence(newstack, start, image, control, clear_all(), kdump_flag)
  *
  * does the grungy work with stack switching and real mode switches
  * also does simple calls to other code
+ *
+ * kdump_flag says whether the next kernel should be a kdump kernel.
  */
 
 _GLOBAL(kexec_sequence)
@@ -647,7 +649,7 @@ _GLOBAL(kexec_sequence)
         mr      r29,r5                  /* image (virt) */
         mr      r28,r6                  /* control, unused */
         mr      r27,r7                  /* clear_all() fn desc */
-        mr      r26,r8                  /* spare */
+        mr      r26,r8                  /* kdump flag */
         lhz     r25,PACAHWCPUID(r13)    /* get our phys cpu from paca */
 
         /* disable interrupts, we are overwriting kernel data next */
@@ -709,5 +711,6 @@ _GLOBAL(kexec_sequence)
         mr      r4,r30  # start, aka phys mem offset
         mtlr    4
         li      r5,0
-        blr     /* image->start(physid, image->start, 0); */
+        mr      r6,r26                  /* kdump_flag */
+        blr     /* image->start(physid, image->start, 0, kdump_flag); */
 #endif /* CONFIG_KEXEC */
diff --git a/arch/powerpc/platforms/cell/ras.c b/arch/powerpc/platforms/cell/ras.c
index 2a14b052abcd..665af1c4195b 100644
--- a/arch/powerpc/platforms/cell/ras.c
+++ b/arch/powerpc/platforms/cell/ras.c
@@ -21,6 +21,7 @@
 #include <asm/machdep.h>
 #include <asm/rtas.h>
 #include <asm/cell-regs.h>
+#include <asm/kdump.h>
 
 #include "ras.h"
 
@@ -111,9 +112,8 @@ static int __init cbe_ptcal_enable_on_node(int nid, int order)
         int ret = -ENOMEM;
         unsigned long addr;
 
-#ifdef CONFIG_CRASH_DUMP
-        rtas_call(ptcal_stop_tok, 1, 1, NULL, nid);
-#endif
+        if (__kdump_flag)
+                rtas_call(ptcal_stop_tok, 1, 1, NULL, nid);
 
         area = kmalloc(sizeof(*area), GFP_KERNEL);
         if (!area)
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index a8c446697f9e..d56491d182d3 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -44,6 +44,7 @@
 #include <asm/tce.h>
 #include <asm/ppc-pci.h>
 #include <asm/udbg.h>
+#include <asm/kdump.h>
 
 #include "plpar_wrappers.h"
 
@@ -291,9 +292,8 @@ static void iommu_table_setparms(struct pci_controller *phb,
 
         tbl->it_base = (unsigned long)__va(*basep);
 
-#ifndef CONFIG_CRASH_DUMP
-        memset((void *)tbl->it_base, 0, *sizep);
-#endif
+        if (!__kdump_flag)
+                memset((void *)tbl->it_base, 0, *sizep);
 
         tbl->it_busno = phb->bus->number;