2) Or use the system kernel binary itself as dump-capture kernel and there is
no need to build a separate dump-capture kernel. This is possible
only with the architecutres which support a relocatable kernel. As
- of today, i386, x86_64 and ia64 architectures support relocatable kernel.
+ of today, i386, x86_64, ppc64 and ia64 architectures support relocatable
+ kernel.
Building a relocatable kernel is advantageous from the point of view that
one does not have to build a second kernel for capturing the dump. But
Dump-capture kernel config options (Arch Dependent, ppc64)
----------------------------------------------------------
-* Make and install the kernel and its modules. DO NOT add this kernel
- to the boot loader configuration files.
+1) Enable "Build a kdump crash kernel" support under "Kernel" options:
+
+ CONFIG_CRASH_DUMP=y
+
+2) Enable "Build a relocatable kernel" support
+
+ CONFIG_RELOCATABLE=y
+
+ Make and install the kernel and its modules.
Dump-capture kernel config options (Arch Dependent, ia64)
----------------------------------------------------------
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)"
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
* 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
#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 */
/* 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);
DBG(" <- setup_kdump_trampoline()\n");
}
+#endif /* CONFIG_RELOCATABLE */
/*
* Note: elfcorehdr_addr is not just limited to vmcore. It is also used by
__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.
/* 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
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. */
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.
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.
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",
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;
/* 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 */
/*
* 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!
*/
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 */
}
/*
- * 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)
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 */
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 */
#include <asm/machdep.h>
#include <asm/rtas.h>
#include <asm/cell-regs.h>
+#include <asm/kdump.h>
#include "ras.h"
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)
#include <asm/tce.h>
#include <asm/ppc-pci.h>
#include <asm/udbg.h>
+#include <asm/kdump.h>
#include "plpar_wrappers.h"
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;
projects / kernel / kernel-generic.git / commitdiff