/* * bpf_jit64.h: BPF JIT compiler for PPC64 * * Copyright 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> * IBM Corporation * * 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 _BPF_JIT64_H #define _BPF_JIT64_H #include "bpf_jit.h" /* * Stack layout: * Ensure the top half (upto local_tmp_var) stays consistent * with our redzone usage. * * [ prev sp ] <------------- * [ nv gpr save area ] 6*8 | * [ tail_call_cnt ] 8 | * [ local_tmp_var ] 8 | * fp (r31) --> [ ebpf stack space ] upto 512 | * [ frame header ] 32/112 | * sp (r1) ---> [ stack pointer ] -------------- */ /* for gpr non volatile registers BPG_REG_6 to 10 */ #define BPF_PPC_STACK_SAVE (6*8) /* for bpf JIT code internal usage */ #define BPF_PPC_STACK_LOCALS 16 /* stack frame excluding BPF stack, ensure this is quadword aligned */ #define BPF_PPC_STACKFRAME (STACK_FRAME_MIN_SIZE + \ BPF_PPC_STACK_LOCALS + BPF_PPC_STACK_SAVE) #ifndef __ASSEMBLY__ /* BPF register usage */ #define TMP_REG_1 (MAX_BPF_JIT_REG + 0) #define TMP_REG_2 (MAX_BPF_JIT_REG + 1) /* BPF to ppc register mappings */ static const int b2p[] = { /* function return value */ [BPF_REG_0] = 8, /* function arguments */ [BPF_REG_1] = 3, [BPF_REG_2] = 4, [BPF_REG_3] = 5, [BPF_REG_4] = 6, [BPF_REG_5] = 7, /* non volatile registers */ [BPF_REG_6] = 27, [BPF_REG_7] = 28, [BPF_REG_8] = 29, [BPF_REG_9] = 30, /* frame pointer aka BPF_REG_10 */ [BPF_REG_FP] = 31, /* eBPF jit internal registers */ [BPF_REG_AX] = 2, [TMP_REG_1] = 9, [TMP_REG_2] = 10 }; /* PPC NVR range -- update this if we ever use NVRs below r27 */ #define BPF_PPC_NVR_MIN 27 #define SEEN_FUNC 0x1000 /* might call external helpers */ #define SEEN_STACK 0x2000 /* uses BPF stack */ #define SEEN_TAILCALL 0x4000 /* uses tail calls */ struct codegen_context { /* * This is used to track register usage as well * as calls to external helpers. * - register usage is tracked with corresponding * bits (r3-r10 and r27-r31) * - rest of the bits can be used to track other * things -- for now, we use bits 16 to 23 * encoded in SEEN_* macros above */ unsigned int seen; unsigned int idx; unsigned int stack_size; }; #endif /* !__ASSEMBLY__ */ #endif