123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183 |
- /* SPDX-License-Identifier: GPL-2.0-only */
- /*
- * bpf_jit.h: BPF JIT compiler for PPC
- *
- * Copyright 2011 Matt Evans <[email protected]>, IBM Corporation
- * 2016 Naveen N. Rao <[email protected]>
- */
- #ifndef _BPF_JIT_H
- #define _BPF_JIT_H
- #ifndef __ASSEMBLY__
- #include <asm/types.h>
- #include <asm/ppc-opcode.h>
- #ifdef CONFIG_PPC64_ELF_ABI_V1
- #define FUNCTION_DESCR_SIZE 24
- #else
- #define FUNCTION_DESCR_SIZE 0
- #endif
- #define PLANT_INSTR(d, idx, instr) \
- do { if (d) { (d)[idx] = instr; } idx++; } while (0)
- #define EMIT(instr) PLANT_INSTR(image, ctx->idx, instr)
- /* Long jump; (unconditional 'branch') */
- #define PPC_JMP(dest) \
- do { \
- long offset = (long)(dest) - (ctx->idx * 4); \
- if ((dest) != 0 && !is_offset_in_branch_range(offset)) { \
- pr_err_ratelimited("Branch offset 0x%lx (@%u) out of range\n", offset, ctx->idx); \
- return -ERANGE; \
- } \
- EMIT(PPC_RAW_BRANCH(offset)); \
- } while (0)
- /* bl (unconditional 'branch' with link) */
- #define PPC_BL(dest) EMIT(PPC_RAW_BL((dest) - (unsigned long)(image + ctx->idx)))
- /* "cond" here covers BO:BI fields. */
- #define PPC_BCC_SHORT(cond, dest) \
- do { \
- long offset = (long)(dest) - (ctx->idx * 4); \
- if ((dest) != 0 && !is_offset_in_cond_branch_range(offset)) { \
- pr_err_ratelimited("Conditional branch offset 0x%lx (@%u) out of range\n", offset, ctx->idx); \
- return -ERANGE; \
- } \
- EMIT(PPC_INST_BRANCH_COND | (((cond) & 0x3ff) << 16) | (offset & 0xfffc)); \
- } while (0)
- /* Sign-extended 32-bit immediate load */
- #define PPC_LI32(d, i) do { \
- if ((int)(uintptr_t)(i) >= -32768 && \
- (int)(uintptr_t)(i) < 32768) \
- EMIT(PPC_RAW_LI(d, i)); \
- else { \
- EMIT(PPC_RAW_LIS(d, IMM_H(i))); \
- if (IMM_L(i)) \
- EMIT(PPC_RAW_ORI(d, d, IMM_L(i))); \
- } } while(0)
- #ifdef CONFIG_PPC64
- #define PPC_LI64(d, i) do { \
- if ((long)(i) >= -2147483648 && \
- (long)(i) < 2147483648) \
- PPC_LI32(d, i); \
- else { \
- if (!((uintptr_t)(i) & 0xffff800000000000ULL)) \
- EMIT(PPC_RAW_LI(d, ((uintptr_t)(i) >> 32) & \
- 0xffff)); \
- else { \
- EMIT(PPC_RAW_LIS(d, ((uintptr_t)(i) >> 48))); \
- if ((uintptr_t)(i) & 0x0000ffff00000000ULL) \
- EMIT(PPC_RAW_ORI(d, d, \
- ((uintptr_t)(i) >> 32) & 0xffff)); \
- } \
- EMIT(PPC_RAW_SLDI(d, d, 32)); \
- if ((uintptr_t)(i) & 0x00000000ffff0000ULL) \
- EMIT(PPC_RAW_ORIS(d, d, \
- ((uintptr_t)(i) >> 16) & 0xffff)); \
- if ((uintptr_t)(i) & 0x000000000000ffffULL) \
- EMIT(PPC_RAW_ORI(d, d, (uintptr_t)(i) & \
- 0xffff)); \
- } } while (0)
- #endif
- /*
- * The fly in the ointment of code size changing from pass to pass is
- * avoided by padding the short branch case with a NOP. If code size differs
- * with different branch reaches we will have the issue of code moving from
- * one pass to the next and will need a few passes to converge on a stable
- * state.
- */
- #define PPC_BCC(cond, dest) do { \
- if (is_offset_in_cond_branch_range((long)(dest) - (ctx->idx * 4))) { \
- PPC_BCC_SHORT(cond, dest); \
- EMIT(PPC_RAW_NOP()); \
- } else { \
- /* Flip the 'T or F' bit to invert comparison */ \
- PPC_BCC_SHORT(cond ^ COND_CMP_TRUE, (ctx->idx+2)*4); \
- PPC_JMP(dest); \
- } } while(0)
- /* To create a branch condition, select a bit of cr0... */
- #define CR0_LT 0
- #define CR0_GT 1
- #define CR0_EQ 2
- /* ...and modify BO[3] */
- #define COND_CMP_TRUE 0x100
- #define COND_CMP_FALSE 0x000
- /* Together, they make all required comparisons: */
- #define COND_GT (CR0_GT | COND_CMP_TRUE)
- #define COND_GE (CR0_LT | COND_CMP_FALSE)
- #define COND_EQ (CR0_EQ | COND_CMP_TRUE)
- #define COND_NE (CR0_EQ | COND_CMP_FALSE)
- #define COND_LT (CR0_LT | COND_CMP_TRUE)
- #define COND_LE (CR0_GT | COND_CMP_FALSE)
- #define SEEN_FUNC 0x20000000 /* might call external helpers */
- #define SEEN_TAILCALL 0x40000000 /* 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-r31)
- * - rest of the bits can be used to track other
- * things -- for now, we use bits 0 to 2
- * encoded in SEEN_* macros above
- */
- unsigned int seen;
- unsigned int idx;
- unsigned int stack_size;
- int b2p[MAX_BPF_JIT_REG + 2];
- unsigned int exentry_idx;
- unsigned int alt_exit_addr;
- };
- #define bpf_to_ppc(r) (ctx->b2p[r])
- #ifdef CONFIG_PPC32
- #define BPF_FIXUP_LEN 3 /* Three instructions => 12 bytes */
- #else
- #define BPF_FIXUP_LEN 2 /* Two instructions => 8 bytes */
- #endif
- static inline void bpf_flush_icache(void *start, void *end)
- {
- smp_wmb(); /* smp write barrier */
- flush_icache_range((unsigned long)start, (unsigned long)end);
- }
- static inline bool bpf_is_seen_register(struct codegen_context *ctx, int i)
- {
- return ctx->seen & (1 << (31 - i));
- }
- static inline void bpf_set_seen_register(struct codegen_context *ctx, int i)
- {
- ctx->seen |= 1 << (31 - i);
- }
- static inline void bpf_clear_seen_register(struct codegen_context *ctx, int i)
- {
- ctx->seen &= ~(1 << (31 - i));
- }
- void bpf_jit_init_reg_mapping(struct codegen_context *ctx);
- int bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, u64 func);
- int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *ctx,
- u32 *addrs, int pass);
- void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx);
- void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx);
- void bpf_jit_realloc_regs(struct codegen_context *ctx);
- int bpf_jit_emit_exit_insn(u32 *image, struct codegen_context *ctx, int tmp_reg, long exit_addr);
- int bpf_add_extable_entry(struct bpf_prog *fp, u32 *image, int pass, struct codegen_context *ctx,
- int insn_idx, int jmp_off, int dst_reg);
- #endif
- #endif
|