From 54622f10a6aabb8bb2bdacf3dd070046f03dc246 Mon Sep 17 00:00:00 2001 From: Mohan Kumar M Date: Tue, 21 Oct 2008 17:38:10 +0000 Subject: powerpc: Support for relocatable kdump kernel This adds relocatable kernel support for kdump. With this one can use the same regular kernel to capture the kdump. A signature (0xfeed1234) is passed in r6 from panic code to the next kernel through kexec_sequence and purgatory code. The signature is used to differentiate between kdump kernel and non-kdump kernels. The purgatory code compares the signature and sets the __kdump_flag in head_64.S. During the boot up, kernel code checks __kdump_flag and if it is set, the kernel will behave as relocatable kdump kernel. This kernel will boot at the address where it was loaded by kexec-tools ie. at the address reserved through crashkernel boot parameter. CONFIG_CRASH_DUMP depends on CONFIG_RELOCATABLE option to build kdump kernel as relocatable. So the same kernel can be used as production and kdump kernel. This patch incorporates the changes suggested by Paul Mackerras to avoid GOT use and to avoid two copies of the code. Signed-off-by: Paul Mackerras Signed-off-by: Mohan Kumar M Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/platforms/cell/ras.c | 6 +++--- arch/powerpc/platforms/pseries/iommu.c | 6 +++--- 2 files changed, 6 insertions(+), 6 deletions(-) (limited to 'arch/powerpc/platforms') diff --git a/arch/powerpc/platforms/cell/ras.c b/arch/powerpc/platforms/cell/ras.c index 2a14b052abc..665af1c4195 100644 --- a/arch/powerpc/platforms/cell/ras.c +++ b/arch/powerpc/platforms/cell/ras.c @@ -21,6 +21,7 @@ #include #include #include +#include #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 a8c446697f9..d56491d182d 100644 --- a/arch/powerpc/platforms/pseries/iommu.c +++ b/arch/powerpc/platforms/pseries/iommu.c @@ -44,6 +44,7 @@ #include #include #include +#include #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; -- cgit v1.2.3