diff options
Diffstat (limited to 'arch/powerpc/net/bpf_jit64.h')
-rw-r--r-- | arch/powerpc/net/bpf_jit64.h | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/arch/powerpc/net/bpf_jit64.h b/arch/powerpc/net/bpf_jit64.h new file mode 100644 index 000000000..61ed9a4b2 --- /dev/null +++ b/arch/powerpc/net/bpf_jit64.h @@ -0,0 +1,112 @@ +/* + * 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 ] 5*8 | + * [ tail_call_cnt ] 8 | + * [ local_tmp_var ] 16 | + * 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 (5*8) +/* for bpf JIT code internal usage */ +#define BPF_PPC_STACK_LOCALS 24 +/* 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 + +/* + * WARNING: These can use TMP_REG_2 if the offset is not at word boundary, + * so ensure that it isn't in use already. + */ +#define PPC_BPF_LL(r, base, i) do { \ + if ((i) % 4) { \ + PPC_LI(b2p[TMP_REG_2], (i)); \ + PPC_LDX(r, base, b2p[TMP_REG_2]); \ + } else \ + PPC_LD(r, base, i); \ + } while(0) +#define PPC_BPF_STL(r, base, i) do { \ + if ((i) % 4) { \ + PPC_LI(b2p[TMP_REG_2], (i)); \ + PPC_STDX(r, base, b2p[TMP_REG_2]); \ + } else \ + PPC_STD(r, base, i); \ + } while(0) +#define PPC_BPF_STLU(r, base, i) do { PPC_STDU(r, base, i); } while(0) + +#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 |