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>
35 lines
1 KiB
C
35 lines
1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef __S390_EXTABLE_H
|
|
#define __S390_EXTABLE_H
|
|
/*
|
|
* The exception table consists of pairs of addresses: the first is the
|
|
* address of an instruction that is allowed to fault, and the second is
|
|
* the address at which the program should continue. No registers are
|
|
* modified, so it is entirely up to the continuation code to figure out
|
|
* what to do.
|
|
*
|
|
* All the routines below use bits of fixup code that are out of line
|
|
* with the main instruction path. This means when everything is well,
|
|
* we don't even have to jump over them. Further, they do not intrude
|
|
* on our cache or tlb entries.
|
|
*/
|
|
|
|
struct exception_table_entry
|
|
{
|
|
int insn, fixup;
|
|
};
|
|
|
|
extern struct exception_table_entry *__start_dma_ex_table;
|
|
extern struct exception_table_entry *__stop_dma_ex_table;
|
|
|
|
const struct exception_table_entry *s390_search_extables(unsigned long addr);
|
|
|
|
static inline unsigned long extable_fixup(const struct exception_table_entry *x)
|
|
{
|
|
return (unsigned long)&x->fixup + x->fixup;
|
|
}
|
|
|
|
#define ARCH_HAS_RELATIVE_EXTABLE
|
|
|
|
#endif
|