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Fix 4-bit code field values in tables
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Signed-off-by: Dave Thaler <[email protected]>
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@dthaler
dthaler committed Sep 23, 2022
1 parent 11bf818 commit c0145f4
Showing 1 changed file with 26 additions and 26 deletions.
52 changes: 26 additions & 26 deletions isa/kernel.org/instruction-set.rst
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Original file line number Diff line number Diff line change
Expand Up @@ -109,9 +109,9 @@ The encoding of the 'opcode' field varies and can be determined from
the three least significant bits (LSB) of the 'opcode' field which holds
the "instruction class", as follows:

========= ===== =============================== =================
========= ===== =============================== ===================================
class value description reference
========= ===== =============================== =================
========= ===== =============================== ===================================
BPF_LD 0x00 non-standard load operations `Load and store instructions`_
BPF_LDX 0x01 load into register operations `Load and store instructions`_
BPF_ST 0x02 store from immediate operations `Load and store instructions`_
Expand All @@ -120,7 +120,7 @@ BPF_ALU 0x04 32-bit arithmetic operations `Arithmetic and jump instruct
BPF_JMP 0x05 64-bit jump operations `Arithmetic and jump instructions`_
BPF_JMP32 0x06 32-bit jump operations `Arithmetic and jump instructions`_
BPF_ALU64 0x07 64-bit arithmetic operations `Arithmetic and jump instructions`_
========= ===== =============================== =================
========= ===== =============================== ===================================

Arithmetic and jump instructions
================================
Expand All @@ -140,12 +140,12 @@ code
source
the source operand location, which unless otherwise specified is one of:

====== ===== ========================================
====== ===== ==========================================
source value description
====== ===== ========================================
====== ===== ==========================================
BPF_K 0x00 use 32-bit 'imm' value as source operand
BPF_X 0x08 use 'src' register value as source operand
====== ===== ========================================
====== ===== ==========================================

instruction class
the instruction class (see `Instruction classes`_)
Expand All @@ -159,9 +159,9 @@ otherwise identical operations.

The 4-bit 'code' field encodes the operation as follows:

======== ===== =================================================
======== ===== ==========================================================
code value description
======== ===== =================================================
======== ===== ==========================================================
BPF_ADD 0x00 dst += src
BPF_SUB 0x10 dst -= src
BPF_MUL 0x20 dst \*= src
Expand All @@ -176,7 +176,7 @@ BPF_XOR 0xa0 dst ^= src
BPF_MOV 0xb0 dst = src
BPF_ARSH 0xc0 sign extending shift right
BPF_END 0xd0 byte swap operations (see `Byte swap instructions`_ below)
======== ===== =================================================
======== ===== ==========================================================

where 'src' is the source operand value.

Expand Down Expand Up @@ -268,22 +268,22 @@ The 4-bit 'code' field encodes the operation as below, where PC is the program c
======== ===== === ========================== ========================
code value src description notes
======== ===== === ========================== ========================
BPF_JA 0x00 0x0 PC += offset BPF_JMP only
BPF_JEQ 0x10 any PC += offset if dst == src
BPF_JGT 0x20 any PC += offset if dst > src unsigned
BPF_JGE 0x30 any PC += offset if dst >= src unsigned
BPF_JSET 0x40 any PC += offset if dst & src
BPF_JNE 0x50 any PC += offset if dst != src
BPF_JSGT 0x60 any PC += offset if dst > src signed
BPF_JSGE 0x70 any PC += offset if dst >= src signed
BPF_CALL 0x80 0x0 call helper function imm see `Helper functions`_
BPF_CALL 0x80 0x1 call PC += offset see `eBPF functions`_
BPF_CALL 0x80 0x2 call runtime function imm see `Runtime functions`_
BPF_EXIT 0x95 0x0 return BPF_JMP only
BPF_JLT 0xa0 any PC += offset if dst < src unsigned
BPF_JLE 0xb0 any PC += offset if dst <= src unsigned
BPF_JSLT 0xc0 any PC += offset if dst < src signed
BPF_JSLE 0xd0 any PC += offset if dst <= src signed
BPF_JA 0x0 0x0 PC += offset BPF_JMP only
BPF_JEQ 0x1 any PC += offset if dst == src
BPF_JGT 0x2 any PC += offset if dst > src unsigned
BPF_JGE 0x3 any PC += offset if dst >= src unsigned
BPF_JSET 0x4 any PC += offset if dst & src
BPF_JNE 0x5 any PC += offset if dst != src
BPF_JSGT 0x6 any PC += offset if dst > src signed
BPF_JSGE 0x7 any PC += offset if dst >= src signed
BPF_CALL 0x8 0x0 call helper function imm see `Helper functions`_
BPF_CALL 0x8 0x1 call PC += offset see `eBPF functions`_
BPF_CALL 0x8 0x2 call runtime function imm see `Runtime functions`_
BPF_EXIT 0x9 0x0 return BPF_JMP only
BPF_JLT 0xa any PC += offset if dst < src unsigned
BPF_JLE 0xb any PC += offset if dst <= src unsigned
BPF_JSLT 0xc any PC += offset if dst < src signed
BPF_JSLE 0xd any PC += offset if dst <= src signed
======== ===== === ========================== ========================

Helper functions
Expand Down Expand Up @@ -401,7 +401,7 @@ The 'imm' field is used to encode the actual atomic operation.
Simple atomic operation use a subset of the values defined to encode
arithmetic operations in the 'imm' field to encode the atomic operation:

======== ===== ===========
======== ===== ===========
imm value description
======== ===== ===========
BPF_ADD 0x00 atomic add
Expand Down

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