a80313ff91
With a relocatable kernel that could reside at any place in memory, code and data that has to stay below 2 GB needs special handling. This patch introduces .dma sections for such text, data and ex_table. The sections will be part of the decompressor kernel, so they will not be relocated and stay below 2 GB. Their location is passed over to the decompressed / relocated kernel via the .boot.preserved.data section. The duald and aste for control register setup also need to stay below 2 GB, so move the setup code from arch/s390/kernel/head64.S to arch/s390/boot/head.S. The duct and linkage_stack could reside above 2 GB, but their content has to be preserved for the decompresed kernel, so they are also moved into the .dma section. The start and end address of the .dma sections is added to vmcoreinfo, for crash support, to help debugging in case the kernel crashed there. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
30 lines
1.0 KiB
C
30 lines
1.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _S390_SECTIONS_H
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#define _S390_SECTIONS_H
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#include <asm-generic/sections.h>
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/*
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* .boot.data section contains variables "shared" between the decompressor and
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* the decompressed kernel. The decompressor will store values in them, and
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* copy over to the decompressed image before starting it.
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*
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* Each variable end up in its own intermediate section .boot.data.<var name>,
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* those sections are later sorted by alignment + name and merged together into
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* final .boot.data section, which should be identical in the decompressor and
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* the decompressed kernel (that is checked during the build).
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*/
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#define __bootdata(var) __section(.boot.data.var) var
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/*
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* .boot.preserved.data is similar to .boot.data, but it is not part of the
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* .init section and thus will be preserved for later use in the decompressed
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* kernel.
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*/
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#define __bootdata_preserved(var) __section(.boot.preserved.data.var) var
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extern unsigned long __sdma, __edma;
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extern unsigned long __stext_dma, __etext_dma;
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#endif
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