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path: root/include/asm-powerpc/kdump.h
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2008-04-24[POWERPC] 85xx: Add support for relocatable kernel (and booting at non-zero)Kumar Gala
Added support to allow an 85xx kernel to be run from a non-zero physical address (useful for cooperative asymmetric multiprocessing situations and kdump). The support can be configured at compile time by setting CONFIG_PAGE_OFFSET, CONFIG_KERNEL_START, and CONFIG_PHYSICAL_START as desired. Alternatively, the kernel build can set CONFIG_RELOCATABLE. Setting this config option causes the kernel to determine at runtime the physical addresses of CONFIG_PAGE_OFFSET and CONFIG_KERNEL_START. If CONFIG_RELOCATABLE is set, then CONFIG_PHYSICAL_START has no meaning. However, CONFIG_PHYSICAL_START will always be used to set the LOAD program header physical address field in the resulting ELF image. Currently we are limited to running at a physical address that is a multiple of 256M. This is due to how we map TLBs to cover lowmem. This should be fixed to allow 64M or maybe even 16M alignment in the future. It is considered an error to try and run a kernel at a non-aligned physical address. All the magic for this support is accomplished by proper initialization of the kernel memory subsystem and use of ARCH_PFN_OFFSET. The use of ARCH_PFN_OFFSET only affects normal memory and not IO mappings. ioremap uses map_page and isn't affected by ARCH_PFN_OFFSET. /dev/mem continues to allow access to any physical address in the system regardless of how CONFIG_PHYSICAL_START is set. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-09-13[POWERPC] kdump: Support kernels having 64k page size.Sachin P. Sant
This is required to generate proper core files using kdump on ppc64. Create a backup region of 64K size irrespective of the PAGE SIZE. At present 32K was used as backup size. In the case of 64K page size, second PT_LOAD segments starts at 32K and the first one is not page aligned. __ioremap() (crash_dump.c) fails if pfn = 0 which is the case for the second PT_LOAD segment. This is not an issue for 4K page size because the the first page (32K backup) is copied to second kernel memory and thus referencing with the second kernel pfn. Signed-off-by: Sachin Sant <sachinp@in.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-28[POWERPC] kdump: Reserve the existing TCE mappings left by the first kernelHaren Myneni
During kdump boot, noticed some machines checkstop on dma protection fault for ongoing DMA left in the first kernel. Instead of initializing TCE entries in iommu_init() for the kdump boot, this patch fixes this issue by walking through the each TCE table and checks whether the entries are in use by the first kernel. If so, reserve those entries by setting the corresponding bit in tbl->it_map such that these entries will not be available for the kdump boot. However it could be possible that all TCE entries might be used up due to the driver bug that does continuous mapping. My observation is around 1700 TCE entries are used on some systems (Ex: P4) at some point of time during kdump boot and saving dump (either write into the disk or sending to remote machine). Hence, this patch will make sure that minimum of 2048 entries will be available such that kdump boot could be successful in some cases. Signed-off-by: Haren Myneni <haren@us.ibm.com> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-05-19[PATCH] powerpc: Kdump header cleanupMichael Ellerman
We need to know the base address of the kdump kernel even when we're not a kdump kernel, so add a #define for it. Move the logic that sets the kdump kernelbase into kdump.h instead of page.h. Rename kdump_setup() to setup_kdump_trampoline() to make it clearer what it's doing, and add an empty definition for the !CRASH_DUMP case to avoid a Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-09[PATCH] powerpc: Reroute interrupts from 0 + offset to PHYSICAL_START + offsetMichael Ellerman
Regardless of where the kernel's linked we always get interrupts at low addresses. This patch creates a trampoline in the first 3 pages of memory, where interrupts land, and patches those addresses to jump into the real kernel code at PHYSICAL_START. We also need to reserve the trampoline code and a bit more in prom.c Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>