1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_RISCV_EXTABLE_H
3 #define _ASM_RISCV_EXTABLE_H
4
5 /*
6 * The exception table consists of pairs of relative offsets: the first
7 * is the relative offset to an instruction that is allowed to fault,
8 * and the second is the relative offset at which the program should
9 * continue. No registers are modified, so it is entirely up to the
10 * continuation code to figure out what to do.
11 *
12 * All the routines below use bits of fixup code that are out of line
13 * with the main instruction path. This means when everything is well,
14 * we don't even have to jump over them. Further, they do not intrude
15 * on our cache or tlb entries.
16 */
17
18 struct exception_table_entry {
19 int insn, fixup;
20 short type, data;
21 };
22
23 #define ARCH_HAS_RELATIVE_EXTABLE
24
25 #define swap_ex_entry_fixup(a, b, tmp, delta) \
26 do { \
27 (a)->fixup = (b)->fixup + (delta); \
28 (b)->fixup = (tmp).fixup - (delta); \
29 (a)->type = (b)->type; \
30 (b)->type = (tmp).type; \
31 (a)->data = (b)->data; \
32 (b)->data = (tmp).data; \
33 } while (0)
34
35 #ifdef CONFIG_MMU
36 bool fixup_exception(struct pt_regs *regs);
37 #else
fixup_exception(struct pt_regs * regs)38 static inline bool fixup_exception(struct pt_regs *regs) { return false; }
39 #endif
40
41 #if defined(CONFIG_BPF_JIT) && defined(CONFIG_ARCH_RV64I)
42 bool ex_handler_bpf(const struct exception_table_entry *ex, struct pt_regs *regs);
43 #else
44 static inline bool
ex_handler_bpf(const struct exception_table_entry * ex,struct pt_regs * regs)45 ex_handler_bpf(const struct exception_table_entry *ex,
46 struct pt_regs *regs)
47 {
48 return false;
49 }
50 #endif
51
52 #endif
53