aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/generic/backport-5.4/071-v5.16-06-mips-bpf-Remove-old-BPF-JIT-implementations.patch
blob: e25c336831dcbb5df0d5c2cb01d93ad2abbe1362 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
From: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Date: Tue, 5 Oct 2021 18:54:08 +0200
Subject: [PATCH] mips: bpf: Remove old BPF JIT implementations

This patch removes the old 32-bit cBPF and 64-bit eBPF JIT implementations.
They are replaced by a new eBPF implementation that supports both 32-bit
and 64-bit MIPS CPUs.

Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
---
 delete mode 100644 arch/mips/net/bpf_jit.c
 delete mode 100644 arch/mips/net/bpf_jit.h
 delete mode 100644 arch/mips/net/bpf_jit_asm.S
 delete mode 100644 arch/mips/net/ebpf_jit.c

--- a/arch/mips/net/bpf_jit.h
+++ /dev/null
@@ -1,81 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Just-In-Time compiler for BPF filters on MIPS
- *
- * Copyright (c) 2014 Imagination Technologies Ltd.
- * Author: Markos Chandras <markos.chandras@imgtec.com>
- */
-
-#ifndef BPF_JIT_MIPS_OP_H
-#define BPF_JIT_MIPS_OP_H
-
-/* Registers used by JIT */
-#define MIPS_R_ZERO	0
-#define MIPS_R_V0	2
-#define MIPS_R_A0	4
-#define MIPS_R_A1	5
-#define MIPS_R_T4	12
-#define MIPS_R_T5	13
-#define MIPS_R_T6	14
-#define MIPS_R_T7	15
-#define MIPS_R_S0	16
-#define MIPS_R_S1	17
-#define MIPS_R_S2	18
-#define MIPS_R_S3	19
-#define MIPS_R_S4	20
-#define MIPS_R_S5	21
-#define MIPS_R_S6	22
-#define MIPS_R_S7	23
-#define MIPS_R_SP	29
-#define MIPS_R_RA	31
-
-/* Conditional codes */
-#define MIPS_COND_EQ	0x1
-#define MIPS_COND_GE	(0x1 << 1)
-#define MIPS_COND_GT	(0x1 << 2)
-#define MIPS_COND_NE	(0x1 << 3)
-#define MIPS_COND_ALL	(0x1 << 4)
-/* Conditionals on X register or K immediate */
-#define MIPS_COND_X	(0x1 << 5)
-#define MIPS_COND_K	(0x1 << 6)
-
-#define r_ret	MIPS_R_V0
-
-/*
- * Use 2 scratch registers to avoid pipeline interlocks.
- * There is no overhead during epilogue and prologue since
- * any of the $s0-$s6 registers will only be preserved if
- * they are going to actually be used.
- */
-#define r_skb_hl	MIPS_R_S0 /* skb header length */
-#define r_skb_data	MIPS_R_S1 /* skb actual data */
-#define r_off		MIPS_R_S2
-#define r_A		MIPS_R_S3
-#define r_X		MIPS_R_S4
-#define r_skb		MIPS_R_S5
-#define r_M		MIPS_R_S6
-#define r_skb_len	MIPS_R_S7
-#define r_s0		MIPS_R_T4 /* scratch reg 1 */
-#define r_s1		MIPS_R_T5 /* scratch reg 2 */
-#define r_tmp_imm	MIPS_R_T6 /* No need to preserve this */
-#define r_tmp		MIPS_R_T7 /* No need to preserve this */
-#define r_zero		MIPS_R_ZERO
-#define r_sp		MIPS_R_SP
-#define r_ra		MIPS_R_RA
-
-#ifndef __ASSEMBLY__
-
-/* Declare ASM helpers */
-
-#define DECLARE_LOAD_FUNC(func) \
-	extern u8 func(unsigned long *skb, int offset); \
-	extern u8 func##_negative(unsigned long *skb, int offset); \
-	extern u8 func##_positive(unsigned long *skb, int offset)
-
-DECLARE_LOAD_FUNC(sk_load_word);
-DECLARE_LOAD_FUNC(sk_load_half);
-DECLARE_LOAD_FUNC(sk_load_byte);
-
-#endif
-
-#endif /* BPF_JIT_MIPS_OP_H */
--- a/arch/mips/net/bpf_jit_asm.S
+++ /dev/null
@@ -1,285 +0,0 @@
-/*
- * bpf_jib_asm.S: Packet/header access helper functions for MIPS/MIPS64 BPF
- * compiler.
- *
- * Copyright (C) 2015 Imagination Technologies Ltd.
- * Author: Markos Chandras <markos.chandras@imgtec.com>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the
- * Free Software Foundation; version 2 of the License.
- */
-
-#include <asm/asm.h>
-#include <asm/isa-rev.h>
-#include <asm/regdef.h>
-#include "bpf_jit.h"
-
-/* ABI
- *
- * r_skb_hl	skb header length
- * r_skb_data	skb data
- * r_off(a1)	offset register
- * r_A		BPF register A
- * r_X		PF register X
- * r_skb(a0)	*skb
- * r_M		*scratch memory
- * r_skb_le	skb length
- * r_s0		Scratch register 0
- * r_s1		Scratch register 1
- *
- * On entry:
- * a0: *skb
- * a1: offset (imm or imm + X)
- *
- * All non-BPF-ABI registers are free for use. On return, we only
- * care about r_ret. The BPF-ABI registers are assumed to remain
- * unmodified during the entire filter operation.
- */
-
-#define skb	a0
-#define offset	a1
-#define SKF_LL_OFF  (-0x200000) /* Can't include linux/filter.h in assembly */
-
-	/* We know better :) so prevent assembler reordering etc */
-	.set 	noreorder
-
-#define is_offset_negative(TYPE)				\
-	/* If offset is negative we have more work to do */	\
-	slti	t0, offset, 0;					\
-	bgtz	t0, bpf_slow_path_##TYPE##_neg;			\
-	/* Be careful what follows in DS. */
-
-#define is_offset_in_header(SIZE, TYPE)				\
-	/* Reading from header? */				\
-	addiu	$r_s0, $r_skb_hl, -SIZE;			\
-	slt	t0, $r_s0, offset;				\
-	bgtz	t0, bpf_slow_path_##TYPE;			\
-
-LEAF(sk_load_word)
-	is_offset_negative(word)
-FEXPORT(sk_load_word_positive)
-	is_offset_in_header(4, word)
-	/* Offset within header boundaries */
-	PTR_ADDU t1, $r_skb_data, offset
-	.set	reorder
-	lw	$r_A, 0(t1)
-	.set	noreorder
-#ifdef CONFIG_CPU_LITTLE_ENDIAN
-# if MIPS_ISA_REV >= 2
-	wsbh	t0, $r_A
-	rotr	$r_A, t0, 16
-# else
-	sll	t0, $r_A, 24
-	srl	t1, $r_A, 24
-	srl	t2, $r_A, 8
-	or	t0, t0, t1
-	andi	t2, t2, 0xff00
-	andi	t1, $r_A, 0xff00
-	or	t0, t0, t2
-	sll	t1, t1, 8
-	or	$r_A, t0, t1
-# endif
-#endif
-	jr	$r_ra
-	 move	$r_ret, zero
-	END(sk_load_word)
-
-LEAF(sk_load_half)
-	is_offset_negative(half)
-FEXPORT(sk_load_half_positive)
-	is_offset_in_header(2, half)
-	/* Offset within header boundaries */
-	PTR_ADDU t1, $r_skb_data, offset
-	lhu	$r_A, 0(t1)
-#ifdef CONFIG_CPU_LITTLE_ENDIAN
-# if MIPS_ISA_REV >= 2
-	wsbh	$r_A, $r_A
-# else
-	sll	t0, $r_A, 8
-	srl	t1, $r_A, 8
-	andi	t0, t0, 0xff00
-	or	$r_A, t0, t1
-# endif
-#endif
-	jr	$r_ra
-	 move	$r_ret, zero
-	END(sk_load_half)
-
-LEAF(sk_load_byte)
-	is_offset_negative(byte)
-FEXPORT(sk_load_byte_positive)
-	is_offset_in_header(1, byte)
-	/* Offset within header boundaries */
-	PTR_ADDU t1, $r_skb_data, offset
-	lbu	$r_A, 0(t1)
-	jr	$r_ra
-	 move	$r_ret, zero
-	END(sk_load_byte)
-
-/*
- * call skb_copy_bits:
- * (prototype in linux/skbuff.h)
- *
- * int skb_copy_bits(sk_buff *skb, int offset, void *to, int len)
- *
- * o32 mandates we leave 4 spaces for argument registers in case
- * the callee needs to use them. Even though we don't care about
- * the argument registers ourselves, we need to allocate that space
- * to remain ABI compliant since the callee may want to use that space.
- * We also allocate 2 more spaces for $r_ra and our return register (*to).
- *
- * n64 is a bit different. The *caller* will allocate the space to preserve
- * the arguments. So in 64-bit kernels, we allocate the 4-arg space for no
- * good reason but it does not matter that much really.
- *
- * (void *to) is returned in r_s0
- *
- */
-#ifdef CONFIG_CPU_LITTLE_ENDIAN
-#define DS_OFFSET(SIZE) (4 * SZREG)
-#else
-#define DS_OFFSET(SIZE) ((4 * SZREG) + (4 - SIZE))
-#endif
-#define bpf_slow_path_common(SIZE)				\
-	/* Quick check. Are we within reasonable boundaries? */ \
-	LONG_ADDIU	$r_s1, $r_skb_len, -SIZE;		\
-	sltu		$r_s0, offset, $r_s1;			\
-	beqz		$r_s0, fault;				\
-	/* Load 4th argument in DS */				\
-	 LONG_ADDIU	a3, zero, SIZE;				\
-	PTR_ADDIU	$r_sp, $r_sp, -(6 * SZREG);		\
-	PTR_LA		t0, skb_copy_bits;			\
-	PTR_S		$r_ra, (5 * SZREG)($r_sp);		\
-	/* Assign low slot to a2 */				\
-	PTR_ADDIU	a2, $r_sp, DS_OFFSET(SIZE);		\
-	jalr		t0;					\
-	/* Reset our destination slot (DS but it's ok) */	\
-	 INT_S		zero, (4 * SZREG)($r_sp);		\
-	/*							\
-	 * skb_copy_bits returns 0 on success and -EFAULT	\
-	 * on error. Our data live in a2. Do not bother with	\
-	 * our data if an error has been returned.		\
-	 */							\
-	/* Restore our frame */					\
-	PTR_L		$r_ra, (5 * SZREG)($r_sp);		\
-	INT_L		$r_s0, (4 * SZREG)($r_sp);		\
-	bltz		v0, fault;				\
-	 PTR_ADDIU	$r_sp, $r_sp, 6 * SZREG;		\
-	move		$r_ret, zero;				\
-
-NESTED(bpf_slow_path_word, (6 * SZREG), $r_sp)
-	bpf_slow_path_common(4)
-#ifdef CONFIG_CPU_LITTLE_ENDIAN
-# if MIPS_ISA_REV >= 2
-	wsbh	t0, $r_s0
-	jr	$r_ra
-	 rotr	$r_A, t0, 16
-# else
-	sll	t0, $r_s0, 24
-	srl	t1, $r_s0, 24
-	srl	t2, $r_s0, 8
-	or	t0, t0, t1
-	andi	t2, t2, 0xff00
-	andi	t1, $r_s0, 0xff00
-	or	t0, t0, t2
-	sll	t1, t1, 8
-	jr	$r_ra
-	 or	$r_A, t0, t1
-# endif
-#else
-	jr	$r_ra
-	 move	$r_A, $r_s0
-#endif
-
-	END(bpf_slow_path_word)
-
-NESTED(bpf_slow_path_half, (6 * SZREG), $r_sp)
-	bpf_slow_path_common(2)
-#ifdef CONFIG_CPU_LITTLE_ENDIAN
-# if MIPS_ISA_REV >= 2
-	jr	$r_ra
-	 wsbh	$r_A, $r_s0
-# else
-	sll	t0, $r_s0, 8
-	andi	t1, $r_s0, 0xff00
-	andi	t0, t0, 0xff00
-	srl	t1, t1, 8
-	jr	$r_ra
-	 or	$r_A, t0, t1
-# endif
-#else
-	jr	$r_ra
-	 move	$r_A, $r_s0
-#endif
-
-	END(bpf_slow_path_half)
-
-NESTED(bpf_slow_path_byte, (6 * SZREG), $r_sp)
-	bpf_slow_path_common(1)
-	jr	$r_ra
-	 move	$r_A, $r_s0
-
-	END(bpf_slow_path_byte)
-
-/*
- * Negative entry points
- */
-	.macro bpf_is_end_of_data
-	li	t0, SKF_LL_OFF
-	/* Reading link layer data? */
-	slt	t1, offset, t0
-	bgtz	t1, fault
-	/* Be careful what follows in DS. */
-	.endm
-/*
- * call skb_copy_bits:
- * (prototype in linux/filter.h)
- *
- * void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
- *                                            int k, unsigned int size)
- *
- * see above (bpf_slow_path_common) for ABI restrictions
- */
-#define bpf_negative_common(SIZE)					\
-	PTR_ADDIU	$r_sp, $r_sp, -(6 * SZREG);			\
-	PTR_LA		t0, bpf_internal_load_pointer_neg_helper;	\
-	PTR_S		$r_ra, (5 * SZREG)($r_sp);			\
-	jalr		t0;						\
-	 li		a2, SIZE;					\
-	PTR_L		$r_ra, (5 * SZREG)($r_sp);			\
-	/* Check return pointer */					\
-	beqz		v0, fault;					\
-	 PTR_ADDIU	$r_sp, $r_sp, 6 * SZREG;			\
-	/* Preserve our pointer */					\
-	move		$r_s0, v0;					\
-	/* Set return value */						\
-	move		$r_ret, zero;					\
-
-bpf_slow_path_word_neg:
-	bpf_is_end_of_data
-NESTED(sk_load_word_negative, (6 * SZREG), $r_sp)
-	bpf_negative_common(4)
-	jr	$r_ra
-	 lw	$r_A, 0($r_s0)
-	END(sk_load_word_negative)
-
-bpf_slow_path_half_neg:
-	bpf_is_end_of_data
-NESTED(sk_load_half_negative, (6 * SZREG), $r_sp)
-	bpf_negative_common(2)
-	jr	$r_ra
-	 lhu	$r_A, 0($r_s0)
-	END(sk_load_half_negative)
-
-bpf_slow_path_byte_neg:
-	bpf_is_end_of_data
-NESTED(sk_load_byte_negative, (6 * SZREG), $r_sp)
-	bpf_negative_common(1)
-	jr	$r_ra
-	 lbu	$r_A, 0($r_s0)
-	END(sk_load_byte_negative)
-
-fault:
-	jr	$r_ra
-	 addiu $r_ret, zero, 1