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26bc824412
This is a LoongArch port of commit d6e2cc5647 ("arm64: extable: add
`type` and `data` fields").
Subsequent patches will add specialized handlers for fixups, in addition
to the simple PC fixup we have today. In preparation, this patch adds a
new `type` field to struct exception_table_entry, and uses this to
distinguish the fixup and other cases. A `data` field is also added so
that subsequent patches can associate data specific to each exception
site (e.g. register numbers).
Handlers are named ex_handler_*() for consistency, following the example
of x86. At the same time, get_ex_fixup() is split out into a helper so
that it can be used by other ex_handler_*() functions in the subsequent
patches.
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
38 lines
1.1 KiB
C
38 lines
1.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_LOONGARCH_EXTABLE_H
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#define _ASM_LOONGARCH_EXTABLE_H
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/*
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* The exception table consists of pairs of relative offsets: the first
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* is the relative offset to an instruction that is allowed to fault,
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* and the second is the relative offset at which the program should
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* continue. No registers are modified, so it is entirely up to the
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* continuation code to figure out what to do.
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*
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* All the routines below use bits of fixup code that are out of line
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* with the main instruction path. This means when everything is well,
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* we don't even have to jump over them. Further, they do not intrude
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* on our cache or tlb entries.
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*/
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struct exception_table_entry {
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int insn, fixup;
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short type, data;
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};
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#define ARCH_HAS_RELATIVE_EXTABLE
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#define swap_ex_entry_fixup(a, b, tmp, delta) \
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do { \
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(a)->fixup = (b)->fixup + (delta); \
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(b)->fixup = (tmp).fixup - (delta); \
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(a)->type = (b)->type; \
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(b)->type = (tmp).type; \
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(a)->data = (b)->data; \
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(b)->data = (tmp).data; \
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} while (0)
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bool fixup_exception(struct pt_regs *regs);
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#endif
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