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Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001/* SPDX-License-Identifier: GPL-2.0 */
Michael Holzheu05462312015-04-01 16:08:32 +02002/*
3 * BPF Jit compiler defines
4 *
5 * Copyright IBM Corp. 2012,2015
6 *
7 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
8 * Michael Holzheu <holzheu@linux.vnet.ibm.com>
9 */
10
11#ifndef __ARCH_S390_NET_BPF_JIT_H
12#define __ARCH_S390_NET_BPF_JIT_H
13
14#ifndef __ASSEMBLY__
15
16#include <linux/filter.h>
17#include <linux/types.h>
18
Michael Holzheu05462312015-04-01 16:08:32 +020019#endif /* __ASSEMBLY__ */
20
21/*
22 * Stackframe layout (packed stack):
23 *
24 * ^ high
25 * +---------------+ |
26 * | old backchain | |
27 * +---------------+ |
28 * | r15 - r6 | |
Michael Holzheu6651ee02015-06-08 21:51:06 -070029 * +---------------+ |
30 * | 4 byte align | |
31 * | tail_call_cnt | |
Michael Holzheu05462312015-04-01 16:08:32 +020032 * BFP -> +===============+ |
33 * | | |
34 * | BPF stack | |
35 * | | |
Michael Holzheu05462312015-04-01 16:08:32 +020036 * R15+160 -> +---------------+ |
37 * | new backchain | |
38 * R15+152 -> +---------------+ |
39 * | + 152 byte SA | |
40 * R15 -> +---------------+ + low
41 *
42 * We get 160 bytes stack space from calling function, but only use
Michael Holzheu6651ee02015-06-08 21:51:06 -070043 * 12 * 8 byte for old backchain, r15..r6, and tail_call_cnt.
Michael Holzheu78372702017-11-07 19:16:25 +010044 *
45 * The stack size used by the BPF program ("BPF stack" above) is passed
46 * via "aux->stack_depth".
Michael Holzheu05462312015-04-01 16:08:32 +020047 */
Daniel Borkmanne1cf4befa2018-05-04 01:08:22 +020048#define STK_SPACE_ADD (160)
Michael Holzheu6651ee02015-06-08 21:51:06 -070049#define STK_160_UNUSED (160 - 12 * 8)
Michael Holzheu78372702017-11-07 19:16:25 +010050#define STK_OFF (STK_SPACE_ADD - STK_160_UNUSED)
Michael Holzheu05462312015-04-01 16:08:32 +020051
Michael Holzheu6651ee02015-06-08 21:51:06 -070052#define STK_OFF_R6 (160 - 11 * 8) /* Offset of r6 on stack */
53#define STK_OFF_TCCNT (160 - 12 * 8) /* Offset of tail_call_cnt on stack */
54
Michael Holzheu05462312015-04-01 16:08:32 +020055#endif /* __ARCH_S390_NET_BPF_JIT_H */