/* SPDX-License-Identifier: GPL-2.0-only */ /* * bpf_jit.h: BPF JIT compiler for PPC * * Copyright 2011 Matt Evans , IBM Corporation * 2016 Naveen N. Rao */ #ifndef _BPF_JIT_H #define _BPF_JIT_H #ifndef __ASSEMBLY__ #include #include #include #ifdef CONFIG_PPC64_ELF_ABI_V1 #define FUNCTION_DESCR_SIZE 24 #else #define FUNCTION_DESCR_SIZE 0 #endif #define CTX_NIA(ctx) ((unsigned long)ctx->idx * 4) #define SZL sizeof(unsigned long) #define BPF_INSN_SAFETY 64 #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_NIA(ctx); \ 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) /* "cond" here covers BO:BI fields. */ #define PPC_BCC_SHORT(cond, dest) \ do { \ long offset = (long)(dest) - CTX_NIA(ctx); \ 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) #define PPC_LI_ADDR PPC_LI64 #ifndef CONFIG_PPC_KERNEL_PCREL #define PPC64_LOAD_PACA() \ EMIT(PPC_RAW_LD(_R2, _R13, offsetof(struct paca_struct, kernel_toc))) #else #define PPC64_LOAD_PACA() do {} while (0) #endif #else #define PPC_LI64(d, i) BUILD_BUG() #define PPC_LI_ADDR PPC_LI32 #define PPC64_LOAD_PACA() BUILD_BUG() #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_NIA(ctx))) { \ 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_NIA(ctx) + 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 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, u32 *fimage, struct codegen_context *ctx, u64 func); int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, u32 *fimage, struct codegen_context *ctx, u32 *addrs, int pass, bool extra_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_build_fentry_stubs(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, u32 *fimage, int pass, struct codegen_context *ctx, int insn_idx, int jmp_off, int dst_reg); #endif #endif