113 lines
3 KiB
C
Executable file
113 lines
3 KiB
C
Executable file
/*
|
|
* 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
|
|
|
|
/*
|
|
* 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
|