ALSA: mips: Convert to the common vmalloc memalloc
[sfrench/cifs-2.6.git] / arch / powerpc / net / bpf_jit64.h
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * bpf_jit64.h: BPF JIT compiler for PPC64
4  *
5  * Copyright 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
6  *                IBM Corporation
7  */
8 #ifndef _BPF_JIT64_H
9 #define _BPF_JIT64_H
10
11 #include "bpf_jit.h"
12
13 /*
14  * Stack layout:
15  * Ensure the top half (upto local_tmp_var) stays consistent
16  * with our redzone usage.
17  *
18  *              [       prev sp         ] <-------------
19  *              [   nv gpr save area    ] 6*8           |
20  *              [    tail_call_cnt      ] 8             |
21  *              [    local_tmp_var      ] 8             |
22  * fp (r31) --> [   ebpf stack space    ] upto 512      |
23  *              [     frame header      ] 32/112        |
24  * sp (r1) ---> [    stack pointer      ] --------------
25  */
26
27 /* for gpr non volatile registers BPG_REG_6 to 10 */
28 #define BPF_PPC_STACK_SAVE      (6*8)
29 /* for bpf JIT code internal usage */
30 #define BPF_PPC_STACK_LOCALS    16
31 /* stack frame excluding BPF stack, ensure this is quadword aligned */
32 #define BPF_PPC_STACKFRAME      (STACK_FRAME_MIN_SIZE + \
33                                  BPF_PPC_STACK_LOCALS + BPF_PPC_STACK_SAVE)
34
35 #ifndef __ASSEMBLY__
36
37 /* BPF register usage */
38 #define TMP_REG_1       (MAX_BPF_JIT_REG + 0)
39 #define TMP_REG_2       (MAX_BPF_JIT_REG + 1)
40
41 /* BPF to ppc register mappings */
42 static const int b2p[] = {
43         /* function return value */
44         [BPF_REG_0] = 8,
45         /* function arguments */
46         [BPF_REG_1] = 3,
47         [BPF_REG_2] = 4,
48         [BPF_REG_3] = 5,
49         [BPF_REG_4] = 6,
50         [BPF_REG_5] = 7,
51         /* non volatile registers */
52         [BPF_REG_6] = 27,
53         [BPF_REG_7] = 28,
54         [BPF_REG_8] = 29,
55         [BPF_REG_9] = 30,
56         /* frame pointer aka BPF_REG_10 */
57         [BPF_REG_FP] = 31,
58         /* eBPF jit internal registers */
59         [BPF_REG_AX] = 2,
60         [TMP_REG_1] = 9,
61         [TMP_REG_2] = 10
62 };
63
64 /* PPC NVR range -- update this if we ever use NVRs below r27 */
65 #define BPF_PPC_NVR_MIN         27
66
67 /*
68  * WARNING: These can use TMP_REG_2 if the offset is not at word boundary,
69  * so ensure that it isn't in use already.
70  */
71 #define PPC_BPF_LL(r, base, i) do {                                           \
72                                 if ((i) % 4) {                                \
73                                         PPC_LI(b2p[TMP_REG_2], (i));          \
74                                         PPC_LDX(r, base, b2p[TMP_REG_2]);     \
75                                 } else                                        \
76                                         PPC_LD(r, base, i);                   \
77                                 } while(0)
78 #define PPC_BPF_STL(r, base, i) do {                                          \
79                                 if ((i) % 4) {                                \
80                                         PPC_LI(b2p[TMP_REG_2], (i));          \
81                                         PPC_STDX(r, base, b2p[TMP_REG_2]);    \
82                                 } else                                        \
83                                         PPC_STD(r, base, i);                  \
84                                 } while(0)
85 #define PPC_BPF_STLU(r, base, i) do { PPC_STDU(r, base, i); } while(0)
86
87 #define SEEN_FUNC       0x1000 /* might call external helpers */
88 #define SEEN_STACK      0x2000 /* uses BPF stack */
89 #define SEEN_TAILCALL   0x4000 /* uses tail calls */
90
91 struct codegen_context {
92         /*
93          * This is used to track register usage as well
94          * as calls to external helpers.
95          * - register usage is tracked with corresponding
96          *   bits (r3-r10 and r27-r31)
97          * - rest of the bits can be used to track other
98          *   things -- for now, we use bits 16 to 23
99          *   encoded in SEEN_* macros above
100          */
101         unsigned int seen;
102         unsigned int idx;
103         unsigned int stack_size;
104 };
105
106 #endif /* !__ASSEMBLY__ */
107
108 #endif