xref: /OK3568_Linux_fs/kernel/arch/s390/net/bpf_jit.h (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  * BPF Jit compiler defines
4*4882a593Smuzhiyun  *
5*4882a593Smuzhiyun  * Copyright IBM Corp. 2012,2015
6*4882a593Smuzhiyun  *
7*4882a593Smuzhiyun  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
8*4882a593Smuzhiyun  *	      Michael Holzheu <holzheu@linux.vnet.ibm.com>
9*4882a593Smuzhiyun  */
10*4882a593Smuzhiyun 
11*4882a593Smuzhiyun #ifndef __ARCH_S390_NET_BPF_JIT_H
12*4882a593Smuzhiyun #define __ARCH_S390_NET_BPF_JIT_H
13*4882a593Smuzhiyun 
14*4882a593Smuzhiyun #ifndef __ASSEMBLY__
15*4882a593Smuzhiyun 
16*4882a593Smuzhiyun #include <linux/filter.h>
17*4882a593Smuzhiyun #include <linux/types.h>
18*4882a593Smuzhiyun 
19*4882a593Smuzhiyun #endif /* __ASSEMBLY__ */
20*4882a593Smuzhiyun 
21*4882a593Smuzhiyun /*
22*4882a593Smuzhiyun  * Stackframe layout (packed stack):
23*4882a593Smuzhiyun  *
24*4882a593Smuzhiyun  *				    ^ high
25*4882a593Smuzhiyun  *	      +---------------+     |
26*4882a593Smuzhiyun  *	      | old backchain |     |
27*4882a593Smuzhiyun  *	      +---------------+     |
28*4882a593Smuzhiyun  *	      |   r15 - r6    |     |
29*4882a593Smuzhiyun  *	      +---------------+     |
30*4882a593Smuzhiyun  *	      | 4 byte align  |     |
31*4882a593Smuzhiyun  *	      | tail_call_cnt |     |
32*4882a593Smuzhiyun  * BFP	   -> +===============+     |
33*4882a593Smuzhiyun  *	      |		      |     |
34*4882a593Smuzhiyun  *	      |   BPF stack   |     |
35*4882a593Smuzhiyun  *	      |		      |     |
36*4882a593Smuzhiyun  * R15+160 -> +---------------+     |
37*4882a593Smuzhiyun  *	      | new backchain |     |
38*4882a593Smuzhiyun  * R15+152 -> +---------------+     |
39*4882a593Smuzhiyun  *	      | + 152 byte SA |     |
40*4882a593Smuzhiyun  * R15	   -> +---------------+     + low
41*4882a593Smuzhiyun  *
42*4882a593Smuzhiyun  * We get 160 bytes stack space from calling function, but only use
43*4882a593Smuzhiyun  * 12 * 8 byte for old backchain, r15..r6, and tail_call_cnt.
44*4882a593Smuzhiyun  *
45*4882a593Smuzhiyun  * The stack size used by the BPF program ("BPF stack" above) is passed
46*4882a593Smuzhiyun  * via "aux->stack_depth".
47*4882a593Smuzhiyun  */
48*4882a593Smuzhiyun #define STK_SPACE_ADD	(160)
49*4882a593Smuzhiyun #define STK_160_UNUSED	(160 - 12 * 8)
50*4882a593Smuzhiyun #define STK_OFF		(STK_SPACE_ADD - STK_160_UNUSED)
51*4882a593Smuzhiyun 
52*4882a593Smuzhiyun #define STK_OFF_R6	(160 - 11 * 8)	/* Offset of r6 on stack */
53*4882a593Smuzhiyun #define STK_OFF_TCCNT	(160 - 12 * 8)	/* Offset of tail_call_cnt on stack */
54*4882a593Smuzhiyun 
55*4882a593Smuzhiyun #endif /* __ARCH_S390_NET_BPF_JIT_H */
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