kernel.git/arch/powerpc/kernel/crash_dump.c, branch linux-2.6.28.y

powerpc: Support for relocatable kdump kernel

2008-10-22T04:01:22Z

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

kdump: make elfcorehdr_addr independent of CONFIG_PROC_VMCORE

2008-10-20T15:52:39Z

o elfcorehdr_addr is used by not only the code under CONFIG_PROC_VMCORE but also by the code which is not inside CONFIG_PROC_VMCORE. For example, is_kdump_kernel() is used by powerpc code to determine if kernel is booting after a panic then use previous kernel's TCE table. So even if CONFIG_PROC_VMCORE is not set in second kernel, one should be able to correctly determine that we are booting after a panic and setup calgary iommu accordingly. o So remove the assumption that elfcorehdr_addr is under CONFIG_PROC_VMCORE. o Move definition of elfcorehdr_addr to arch dependent crash files. (Unfortunately crash dump does not have an arch independent file otherwise that would have been the best place). o kexec.c is not the right place as one can Have CRASH_DUMP enabled in second kernel without KEXEC being enabled. o I don't see sh setup code parsing the command line for elfcorehdr_addr. I am wondering how does vmcore interface work on sh. Anyway, I am atleast defining elfcoredhr_addr so that compilation is not broken on sh. Signed-off-by: Vivek Goyal Acked-by: "Eric W. Biederman" Acked-by: Simon Horman Acked-by: Paul Mundt Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

powerpc: Fix /dev/oldmem interface for kdump

2008-08-19T23:50:21Z

A change to __ioremap() broke reading /dev/oldmem because we're no longer able to ioremap pfn 0 (d177c207, "[PATCH] powerpc: IOMMU: don't ioremap null addresses"). We actually don't need to ioremap for anything that's part of the linear mapping, so just read it directly. Also make sure we're only reading one page or less at a time. Signed-off-by: Michael Ellerman Signed-off-by: Sachin Sant Signed-off-by: Paul Mackerras

powerpc: Add PPC_NOP_INSTR, a hash define for the preferred nop instruction

2008-07-01T01:28:23Z

A bunch of code has hard-coded the value for a "nop" instruction, it would be nice to have a #define for it. Signed-off-by: Michael Ellerman Acked-by: Kumar Gala Signed-off-by: Paul Mackerras

powerpc: Allow create_branch() to return errors

2008-07-01T01:28:19Z

Currently create_branch() creates a branch instruction for you, and patches it into the call site. In some circumstances it would be nice to be able to create the instruction and patch it later, and also some code might want to check for errors in the branch creation before doing the patching. A future commit will change create_branch() to check for errors. For callers that don't care, replace create_branch() with patch_branch(), which just creates the branch and patches it directly. While we're touching all the callers, change to using unsigned int *, as this seems to match usage better. That allows (and requires) us to remove the volatile in the definition of vector in powermac/smp.c and mpc86xx_smp.c, that's correct because now that we're passing vector as an unsigned int * the compiler knows that it's value might change across the patch_branch() call. Signed-off-by: Michael Ellerman Acked-by: Kumar Gala Acked-by: Jon Loeliger Signed-off-by: Paul Mackerras

powerpc: Move code patching code into arch/powerpc/lib/code-patching.c

2008-07-01T01:28:18Z

We currently have a few routines for patching code in asm/system.h, because they didn't fit anywhere else. I'd like to clean them up a little and add some more, so first move them into a dedicated C file - they don't need to be inlined. While we're moving the code, drop create_function_call(), it's intended caller never got merged and will be replaced in future with something different. Signed-off-by: Michael Ellerman Acked-by: Kumar Gala Signed-off-by: Paul Mackerras

[LIB]: Make PowerPC LMB code generic so sparc64 can use it too.

2008-02-14T00:56:49Z

Signed-off-by: David S. Miller

[POWERPC] FWNMI is only used on pSeries

2007-09-19T05:25:34Z

This saves 4k on non pSeries builds (except for iSeries where it saves almost 4k). Signed-off-by: Stephen Rothwell Signed-off-by: Paul Mackerras

[POWERPC] Fix section mismatch in crash_dump.c

2007-08-17T01:02:06Z

WARNING: vmlinux.o(.text+0x23258): Section mismatch: reference to .init.text:.lmb_reserve (between '.reserve_kdump_trampoline' and '.restore_processor_state') Signed-off-by: Stephen Rothwell Signed-off-by: Paul Mackerras

[POWERPC] Make doc comments extractable

2006-08-08T07:07:04Z

We don't have much in the way of doc comments, but some of those we do have don't work because they start with "/***" or "/*", not "/**" which is what kernel-doc requires. Signed-off-by: Michael Ellerman Signed-off-by: Paul Mackerras