kvmfornfv -

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Diffstat (limited to 'kernel/include/linux/spi')

0 files changed, 0 insertions, 0 deletions

/* * 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/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 defined(__mips_isa_rev) && (__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 .set reorder lh $r_A, 0(t1) .set noreorder #ifdef CONFIG_CPU_LITTLE_ENDIAN # if defined(__mips_isa_rev) && (__mips_isa_rev >= 2) wsbh t0, $r_A seh $r_A, t0 # else sll t0, $r_A, 24 andi t1, $r_A, 0xff00 sra t0, t0, 16 srl t1, t1, 8 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 lb $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 * */ #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 */ \ move a2, $r_sp; \ jalr t0; \ /* Reset our destination slot (DS but it's ok) */ \ INT_S zero, (4 * SZREG)($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 defined(__mips_isa_rev) && (__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 defined(__mips_isa_rev) && (__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


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