linux/arch/arm/net/bpf_jit_32.h
Nicolas Schichan 4560cdff03 ARM: net: support BPF_ALU | BPF_MOD instructions in the BPF JIT.
For ARMv7 with UDIV instruction support, generate an UDIV instruction
followed by an MLS instruction.

For other ARM variants, generate code calling a C wrapper similar to
the jit_udiv() function used for BPF_ALU | BPF_DIV instructions.

Some performance numbers reported by the test_bpf module (the duration
per filter run is reported in nanoseconds, between "jitted:<x>" and
"PASS":

ARMv7 QEMU nojit:	test_bpf: #3 DIV_MOD_KX jited:0 2196 PASS
ARMv7 QEMU jit:		test_bpf: #3 DIV_MOD_KX jited:1 104 PASS
ARMv5 QEMU nojit:	test_bpf: #3 DIV_MOD_KX jited:0 2176 PASS
ARMv5 QEMU jit:		test_bpf: #3 DIV_MOD_KX jited:1 1104 PASS
ARMv5 kirkwood nojit:	test_bpf: #3 DIV_MOD_KX jited:0 1103 PASS
ARMv5 kirkwood jit:	test_bpf: #3 DIV_MOD_KX jited:1 311 PASS

Signed-off-by: Nicolas Schichan <nschichan@freebox.fr>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-05 07:02:42 -07:00

219 lines
6.5 KiB
C

/*
* Just-In-Time compiler for BPF filters on 32bit ARM
*
* Copyright (c) 2011 Mircea Gherzan <mgherzan@gmail.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.
*/
#ifndef PFILTER_OPCODES_ARM_H
#define PFILTER_OPCODES_ARM_H
#define ARM_R0 0
#define ARM_R1 1
#define ARM_R2 2
#define ARM_R3 3
#define ARM_R4 4
#define ARM_R5 5
#define ARM_R6 6
#define ARM_R7 7
#define ARM_R8 8
#define ARM_R9 9
#define ARM_R10 10
#define ARM_FP 11
#define ARM_IP 12
#define ARM_SP 13
#define ARM_LR 14
#define ARM_PC 15
#define ARM_COND_EQ 0x0
#define ARM_COND_NE 0x1
#define ARM_COND_CS 0x2
#define ARM_COND_HS ARM_COND_CS
#define ARM_COND_CC 0x3
#define ARM_COND_LO ARM_COND_CC
#define ARM_COND_MI 0x4
#define ARM_COND_PL 0x5
#define ARM_COND_VS 0x6
#define ARM_COND_VC 0x7
#define ARM_COND_HI 0x8
#define ARM_COND_LS 0x9
#define ARM_COND_GE 0xa
#define ARM_COND_LT 0xb
#define ARM_COND_GT 0xc
#define ARM_COND_LE 0xd
#define ARM_COND_AL 0xe
/* register shift types */
#define SRTYPE_LSL 0
#define SRTYPE_LSR 1
#define SRTYPE_ASR 2
#define SRTYPE_ROR 3
#define ARM_INST_ADD_R 0x00800000
#define ARM_INST_ADD_I 0x02800000
#define ARM_INST_AND_R 0x00000000
#define ARM_INST_AND_I 0x02000000
#define ARM_INST_BIC_R 0x01c00000
#define ARM_INST_BIC_I 0x03c00000
#define ARM_INST_B 0x0a000000
#define ARM_INST_BX 0x012FFF10
#define ARM_INST_BLX_R 0x012fff30
#define ARM_INST_CMP_R 0x01500000
#define ARM_INST_CMP_I 0x03500000
#define ARM_INST_EOR_R 0x00200000
#define ARM_INST_EOR_I 0x02200000
#define ARM_INST_LDRB_I 0x05d00000
#define ARM_INST_LDRB_R 0x07d00000
#define ARM_INST_LDRH_I 0x01d000b0
#define ARM_INST_LDRH_R 0x019000b0
#define ARM_INST_LDR_I 0x05900000
#define ARM_INST_LDM 0x08900000
#define ARM_INST_LSL_I 0x01a00000
#define ARM_INST_LSL_R 0x01a00010
#define ARM_INST_LSR_I 0x01a00020
#define ARM_INST_LSR_R 0x01a00030
#define ARM_INST_MOV_R 0x01a00000
#define ARM_INST_MOV_I 0x03a00000
#define ARM_INST_MOVW 0x03000000
#define ARM_INST_MOVT 0x03400000
#define ARM_INST_MUL 0x00000090
#define ARM_INST_POP 0x08bd0000
#define ARM_INST_PUSH 0x092d0000
#define ARM_INST_ORR_R 0x01800000
#define ARM_INST_ORR_I 0x03800000
#define ARM_INST_REV 0x06bf0f30
#define ARM_INST_REV16 0x06bf0fb0
#define ARM_INST_RSB_I 0x02600000
#define ARM_INST_SUB_R 0x00400000
#define ARM_INST_SUB_I 0x02400000
#define ARM_INST_STR_I 0x05800000
#define ARM_INST_TST_R 0x01100000
#define ARM_INST_TST_I 0x03100000
#define ARM_INST_UDIV 0x0730f010
#define ARM_INST_UMULL 0x00800090
#define ARM_INST_MLS 0x00600090
/*
* Use a suitable undefined instruction to use for ARM/Thumb2 faulting.
* We need to be careful not to conflict with those used by other modules
* (BUG, kprobes, etc) and the register_undef_hook() system.
*
* The ARM architecture reference manual guarantees that the following
* instruction space will produce an undefined instruction exception on
* all CPUs:
*
* ARM: xxxx 0111 1111 xxxx xxxx xxxx 1111 xxxx ARMv7-AR, section A5.4
* Thumb: 1101 1110 xxxx xxxx ARMv7-M, section A5.2.6
*/
#define ARM_INST_UDF 0xe7fddef1
/* register */
#define _AL3_R(op, rd, rn, rm) ((op ## _R) | (rd) << 12 | (rn) << 16 | (rm))
/* immediate */
#define _AL3_I(op, rd, rn, imm) ((op ## _I) | (rd) << 12 | (rn) << 16 | (imm))
#define ARM_ADD_R(rd, rn, rm) _AL3_R(ARM_INST_ADD, rd, rn, rm)
#define ARM_ADD_I(rd, rn, imm) _AL3_I(ARM_INST_ADD, rd, rn, imm)
#define ARM_AND_R(rd, rn, rm) _AL3_R(ARM_INST_AND, rd, rn, rm)
#define ARM_AND_I(rd, rn, imm) _AL3_I(ARM_INST_AND, rd, rn, imm)
#define ARM_BIC_R(rd, rn, rm) _AL3_R(ARM_INST_BIC, rd, rn, rm)
#define ARM_BIC_I(rd, rn, imm) _AL3_I(ARM_INST_BIC, rd, rn, imm)
#define ARM_B(imm24) (ARM_INST_B | ((imm24) & 0xffffff))
#define ARM_BX(rm) (ARM_INST_BX | (rm))
#define ARM_BLX_R(rm) (ARM_INST_BLX_R | (rm))
#define ARM_CMP_R(rn, rm) _AL3_R(ARM_INST_CMP, 0, rn, rm)
#define ARM_CMP_I(rn, imm) _AL3_I(ARM_INST_CMP, 0, rn, imm)
#define ARM_EOR_R(rd, rn, rm) _AL3_R(ARM_INST_EOR, rd, rn, rm)
#define ARM_EOR_I(rd, rn, imm) _AL3_I(ARM_INST_EOR, rd, rn, imm)
#define ARM_LDR_I(rt, rn, off) (ARM_INST_LDR_I | (rt) << 12 | (rn) << 16 \
| (off))
#define ARM_LDRB_I(rt, rn, off) (ARM_INST_LDRB_I | (rt) << 12 | (rn) << 16 \
| (off))
#define ARM_LDRB_R(rt, rn, rm) (ARM_INST_LDRB_R | (rt) << 12 | (rn) << 16 \
| (rm))
#define ARM_LDRH_I(rt, rn, off) (ARM_INST_LDRH_I | (rt) << 12 | (rn) << 16 \
| (((off) & 0xf0) << 4) | ((off) & 0xf))
#define ARM_LDRH_R(rt, rn, rm) (ARM_INST_LDRH_R | (rt) << 12 | (rn) << 16 \
| (rm))
#define ARM_LDM(rn, regs) (ARM_INST_LDM | (rn) << 16 | (regs))
#define ARM_LSL_R(rd, rn, rm) (_AL3_R(ARM_INST_LSL, rd, 0, rn) | (rm) << 8)
#define ARM_LSL_I(rd, rn, imm) (_AL3_I(ARM_INST_LSL, rd, 0, rn) | (imm) << 7)
#define ARM_LSR_R(rd, rn, rm) (_AL3_R(ARM_INST_LSR, rd, 0, rn) | (rm) << 8)
#define ARM_LSR_I(rd, rn, imm) (_AL3_I(ARM_INST_LSR, rd, 0, rn) | (imm) << 7)
#define ARM_MOV_R(rd, rm) _AL3_R(ARM_INST_MOV, rd, 0, rm)
#define ARM_MOV_I(rd, imm) _AL3_I(ARM_INST_MOV, rd, 0, imm)
#define ARM_MOVW(rd, imm) \
(ARM_INST_MOVW | ((imm) >> 12) << 16 | (rd) << 12 | ((imm) & 0x0fff))
#define ARM_MOVT(rd, imm) \
(ARM_INST_MOVT | ((imm) >> 12) << 16 | (rd) << 12 | ((imm) & 0x0fff))
#define ARM_MUL(rd, rm, rn) (ARM_INST_MUL | (rd) << 16 | (rm) << 8 | (rn))
#define ARM_POP(regs) (ARM_INST_POP | (regs))
#define ARM_PUSH(regs) (ARM_INST_PUSH | (regs))
#define ARM_ORR_R(rd, rn, rm) _AL3_R(ARM_INST_ORR, rd, rn, rm)
#define ARM_ORR_I(rd, rn, imm) _AL3_I(ARM_INST_ORR, rd, rn, imm)
#define ARM_ORR_S(rd, rn, rm, type, rs) \
(ARM_ORR_R(rd, rn, rm) | (type) << 5 | (rs) << 7)
#define ARM_REV(rd, rm) (ARM_INST_REV | (rd) << 12 | (rm))
#define ARM_REV16(rd, rm) (ARM_INST_REV16 | (rd) << 12 | (rm))
#define ARM_RSB_I(rd, rn, imm) _AL3_I(ARM_INST_RSB, rd, rn, imm)
#define ARM_SUB_R(rd, rn, rm) _AL3_R(ARM_INST_SUB, rd, rn, rm)
#define ARM_SUB_I(rd, rn, imm) _AL3_I(ARM_INST_SUB, rd, rn, imm)
#define ARM_STR_I(rt, rn, off) (ARM_INST_STR_I | (rt) << 12 | (rn) << 16 \
| (off))
#define ARM_TST_R(rn, rm) _AL3_R(ARM_INST_TST, 0, rn, rm)
#define ARM_TST_I(rn, imm) _AL3_I(ARM_INST_TST, 0, rn, imm)
#define ARM_UDIV(rd, rn, rm) (ARM_INST_UDIV | (rd) << 16 | (rn) | (rm) << 8)
#define ARM_UMULL(rd_lo, rd_hi, rn, rm) (ARM_INST_UMULL | (rd_hi) << 16 \
| (rd_lo) << 12 | (rm) << 8 | rn)
#define ARM_MLS(rd, rn, rm, ra) (ARM_INST_MLS | (rd) << 16 | (rn) | (rm) << 8 \
| (ra) << 12)
#endif /* PFILTER_OPCODES_ARM_H */