diff options
Diffstat (limited to 'arch/parisc/net/bpf_jit_core.c')
| -rw-r--r-- | arch/parisc/net/bpf_jit_core.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/arch/parisc/net/bpf_jit_core.c b/arch/parisc/net/bpf_jit_core.c new file mode 100644 index 000000000000..d6ee2fd45550 --- /dev/null +++ b/arch/parisc/net/bpf_jit_core.c @@ -0,0 +1,201 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Common functionality for HPPA32 and HPPA64 BPF JIT compilers + * + * Copyright (c) 2023 Helge Deller <deller@gmx.de> + * + */ + +#include <linux/bpf.h> +#include <linux/filter.h> +#include "bpf_jit.h" + +/* Number of iterations to try until offsets converge. */ +#define NR_JIT_ITERATIONS 35 + +static int build_body(struct hppa_jit_context *ctx, bool extra_pass, int *offset) +{ + const struct bpf_prog *prog = ctx->prog; + int i; + + ctx->reg_seen_collect = true; + for (i = 0; i < prog->len; i++) { + const struct bpf_insn *insn = &prog->insnsi[i]; + int ret; + + ret = bpf_jit_emit_insn(insn, ctx, extra_pass); + /* BPF_LD | BPF_IMM | BPF_DW: skip the next instruction. */ + if (ret > 0) + i++; + if (offset) + offset[i] = ctx->ninsns; + if (ret < 0) + return ret; + } + ctx->reg_seen_collect = false; + return 0; +} + +bool bpf_jit_needs_zext(void) +{ + return true; +} + +struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) +{ + unsigned int prog_size = 0, extable_size = 0; + bool tmp_blinded = false, extra_pass = false; + struct bpf_prog *tmp, *orig_prog = prog; + int pass = 0, prev_ninsns = 0, prologue_len, i; + struct hppa_jit_data *jit_data; + struct hppa_jit_context *ctx; + + if (!prog->jit_requested) + return orig_prog; + + tmp = bpf_jit_blind_constants(prog); + if (IS_ERR(tmp)) + return orig_prog; + if (tmp != prog) { + tmp_blinded = true; + prog = tmp; + } + + jit_data = prog->aux->jit_data; + if (!jit_data) { + jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL); + if (!jit_data) { + prog = orig_prog; + goto out; + } + prog->aux->jit_data = jit_data; + } + + ctx = &jit_data->ctx; + + if (ctx->offset) { + extra_pass = true; + prog_size = sizeof(*ctx->insns) * ctx->ninsns; + goto skip_init_ctx; + } + + ctx->prog = prog; + ctx->offset = kcalloc(prog->len, sizeof(int), GFP_KERNEL); + if (!ctx->offset) { + prog = orig_prog; + goto out_offset; + } + for (i = 0; i < prog->len; i++) { + prev_ninsns += 20; + ctx->offset[i] = prev_ninsns; + } + + for (i = 0; i < NR_JIT_ITERATIONS; i++) { + pass++; + ctx->ninsns = 0; + if (build_body(ctx, extra_pass, ctx->offset)) { + prog = orig_prog; + goto out_offset; + } + ctx->body_len = ctx->ninsns; + bpf_jit_build_prologue(ctx); + ctx->prologue_len = ctx->ninsns - ctx->body_len; + ctx->epilogue_offset = ctx->ninsns; + bpf_jit_build_epilogue(ctx); + + if (ctx->ninsns == prev_ninsns) { + if (jit_data->header) + break; + /* obtain the actual image size */ + extable_size = prog->aux->num_exentries * + sizeof(struct exception_table_entry); + prog_size = sizeof(*ctx->insns) * ctx->ninsns; + + jit_data->header = + bpf_jit_binary_alloc(prog_size + extable_size, + &jit_data->image, + sizeof(u32), + bpf_fill_ill_insns); + if (!jit_data->header) { + prog = orig_prog; + goto out_offset; + } + + ctx->insns = (u32 *)jit_data->image; + /* + * Now, when the image is allocated, the image can + * potentially shrink more (auipc/jalr -> jal). + */ + } + prev_ninsns = ctx->ninsns; + } + + if (i == NR_JIT_ITERATIONS) { + pr_err("bpf-jit: image did not converge in <%d passes!\n", i); + if (jit_data->header) + bpf_jit_binary_free(jit_data->header); + prog = orig_prog; + goto out_offset; + } + + if (extable_size) + prog->aux->extable = (void *)ctx->insns + prog_size; + +skip_init_ctx: + pass++; + ctx->ninsns = 0; + + bpf_jit_build_prologue(ctx); + if (build_body(ctx, extra_pass, NULL)) { + bpf_jit_binary_free(jit_data->header); + prog = orig_prog; + goto out_offset; + } + bpf_jit_build_epilogue(ctx); + + if (HPPA_JIT_DEBUG || bpf_jit_enable > 1) { + if (HPPA_JIT_DUMP) + bpf_jit_dump(prog->len, prog_size, pass, ctx->insns); + if (HPPA_JIT_REBOOT) + { extern int machine_restart(char *); machine_restart(""); } + } + + prog->bpf_func = (void *)ctx->insns; + prog->jited = 1; + prog->jited_len = prog_size; + + bpf_flush_icache(jit_data->header, ctx->insns + ctx->ninsns); + + if (!prog->is_func || extra_pass) { + bpf_jit_binary_lock_ro(jit_data->header); + prologue_len = ctx->epilogue_offset - ctx->body_len; + for (i = 0; i < prog->len; i++) + ctx->offset[i] += prologue_len; + bpf_prog_fill_jited_linfo(prog, ctx->offset); +out_offset: + kfree(ctx->offset); + kfree(jit_data); + prog->aux->jit_data = NULL; + } +out: + if (HPPA_JIT_REBOOT) + { extern int machine_restart(char *); machine_restart(""); } + + if (tmp_blinded) + bpf_jit_prog_release_other(prog, prog == orig_prog ? + tmp : orig_prog); + return prog; +} + +u64 hppa_div64(u64 div, u64 divisor) +{ + div = div64_u64(div, divisor); + return div; +} + +u64 hppa_div64_rem(u64 div, u64 divisor) +{ + u64 rem; + div64_u64_rem(div, divisor, &rem); + return rem; +} |