diff options
Diffstat (limited to 'arch/mips/net/bpf_jit_asm.S')
| -rw-r--r-- | arch/mips/net/bpf_jit_asm.S | 285 |
1 files changed, 0 insertions, 285 deletions
diff --git a/arch/mips/net/bpf_jit_asm.S b/arch/mips/net/bpf_jit_asm.S deleted file mode 100644 index 57154c5883b6..000000000000 --- 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 |