[dpdk-dev] [PATCH 3/8] bpf/arm64: add basic arithmetic operations
jerinj at marvell.com
jerinj at marvell.com
Tue Sep 3 12:59:33 CEST 2019
From: Jerin Jacob <jerinj at marvell.com>
Add mov, add, sub, mul, div and mod arithmetic
operations for immediate and source register variants.
Signed-off-by: Jerin Jacob <jerinj at marvell.com>
---
lib/librte_bpf/bpf_jit_arm64.c | 300 ++++++++++++++++++++++++++++++++-
1 file changed, 299 insertions(+), 1 deletion(-)
diff --git a/lib/librte_bpf/bpf_jit_arm64.c b/lib/librte_bpf/bpf_jit_arm64.c
index 548408a61..5d2ce378c 100644
--- a/lib/librte_bpf/bpf_jit_arm64.c
+++ b/lib/librte_bpf/bpf_jit_arm64.c
@@ -43,6 +43,17 @@ struct a64_jit_ctx {
uint8_t foundcall; /* Found EBPF_CALL class code in eBPF pgm */
};
+static int
+check_mov_hw(bool is64, const uint8_t val)
+{
+ if (val == 16 || val == 0)
+ return 0;
+ else if (is64 && val != 64 && val != 48 && val != 32)
+ return 1;
+
+ return 0;
+}
+
static int
check_reg(uint8_t r)
{
@@ -169,6 +180,179 @@ emit_stack_pop(struct a64_jit_ctx *ctx, uint8_t rt, uint8_t rt2)
emit_ls_pair_64(ctx, rt, rt2, A64_SP, 0, 1, 0);
}
+#define A64_MOVN 0
+#define A64_MOVZ 2
+#define A64_MOVK 3
+static void
+mov_imm(struct a64_jit_ctx *ctx, bool is64, uint8_t rd, uint8_t type,
+ uint16_t imm16, uint8_t shift)
+{
+ uint32_t insn;
+
+ insn = (!!is64) << 31;
+ insn |= type << 29;
+ insn |= 0x25 << 23;
+ insn |= (shift/16) << 21;
+ insn |= imm16 << 5;
+ insn |= rd;
+
+ emit_insn(ctx, insn, check_reg(rd) || check_mov_hw(is64, shift));
+}
+
+static void
+emit_mov_imm32(struct a64_jit_ctx *ctx, bool is64, uint8_t rd, uint32_t val)
+{
+ uint16_t upper = val >> 16;
+ uint16_t lower = val & 0xffff;
+
+ /* Positive number */
+ if ((val & 1UL << 31) == 0) {
+ mov_imm(ctx, is64, rd, A64_MOVZ, lower, 0);
+ if (upper)
+ mov_imm(ctx, is64, rd, A64_MOVK, upper, 16);
+ } else { /* Negative number */
+ if (upper == 0xffff) {
+ mov_imm(ctx, is64, rd, A64_MOVN, ~lower, 0);
+ } else {
+ mov_imm(ctx, is64, rd, A64_MOVN, ~upper, 16);
+ if (lower != 0xffff)
+ mov_imm(ctx, is64, rd, A64_MOVK, lower, 0);
+ }
+ }
+}
+
+static int
+u16_blocks_weight(const uint64_t val, bool one)
+{
+ return (((val >> 0) & 0xffff) == (one ? 0xffff : 0x0000)) +
+ (((val >> 16) & 0xffff) == (one ? 0xffff : 0x0000)) +
+ (((val >> 32) & 0xffff) == (one ? 0xffff : 0x0000)) +
+ (((val >> 48) & 0xffff) == (one ? 0xffff : 0x0000));
+}
+
+static void
+emit_mov_imm(struct a64_jit_ctx *ctx, bool is64, uint8_t rd, uint64_t val)
+{
+ uint64_t nval = ~val;
+ int movn, sr;
+
+ if (is64 == 0)
+ return emit_mov_imm32(ctx, 0, rd, (uint32_t)(val & 0xffffffff));
+
+ /* Find MOVN or MOVZ first */
+ movn = u16_blocks_weight(val, true) > u16_blocks_weight(val, false);
+ /* Find shift right value */
+ sr = movn ? rte_fls_u64(nval) - 1 : rte_fls_u64(val) - 1;
+ sr = RTE_ALIGN_FLOOR(sr, 16);
+ sr = RTE_MAX(sr, 0);
+
+ if (movn)
+ mov_imm(ctx, 1, rd, A64_MOVN, (nval >> sr) & 0xffff, sr);
+ else
+ mov_imm(ctx, 1, rd, A64_MOVZ, (val >> sr) & 0xffff, sr);
+
+ sr -= 16;
+ while (sr >= 0) {
+ if (((val >> sr) & 0xffff) != (movn ? 0xffff : 0x0000))
+ mov_imm(ctx, 1, rd, A64_MOVK, (val >> sr) & 0xffff, sr);
+ sr -= 16;
+ }
+}
+
+#define A64_ADD 0x58
+#define A64_SUB 0x258
+static void
+emit_add_sub(struct a64_jit_ctx *ctx, bool is64, uint8_t rd, uint8_t rn,
+ uint8_t rm, uint16_t op)
+{
+ uint32_t insn;
+
+ insn = (!!is64) << 31;
+ insn |= op << 21; /* shift == 0 */
+ insn |= rm << 16;
+ insn |= rn << 5;
+ insn |= rd;
+
+ emit_insn(ctx, insn, check_reg(rd) || check_reg(rm));
+}
+
+static void
+emit_add(struct a64_jit_ctx *ctx, bool is64, uint8_t rd, uint8_t rm)
+{
+ emit_add_sub(ctx, is64, rd, rd, rm, A64_ADD);
+}
+
+static void
+emit_sub(struct a64_jit_ctx *ctx, bool is64, uint8_t rd, uint8_t rm)
+{
+ emit_add_sub(ctx, is64, rd, rd, rm, A64_SUB);
+}
+
+static void
+emit_mul(struct a64_jit_ctx *ctx, bool is64, uint8_t rd, uint8_t rm)
+{
+ uint32_t insn;
+
+ insn = (!!is64) << 31;
+ insn |= 0xd8 << 21;
+ insn |= rm << 16;
+ insn |= A64_ZR << 10;
+ insn |= rd << 5;
+ insn |= rd;
+
+ emit_insn(ctx, insn, check_reg(rd) || check_reg(rm));
+}
+
+#define A64_UDIV 0x2
+static void
+emit_data_process_two_src(struct a64_jit_ctx *ctx, bool is64, uint8_t rd,
+ uint8_t rn, uint8_t rm, uint16_t op)
+
+{
+ uint32_t insn;
+
+ insn = (!!is64) << 31;
+ insn |= 0xd6 << 21;
+ insn |= rm << 16;
+ insn |= op << 10;
+ insn |= rn << 5;
+ insn |= rd;
+
+ emit_insn(ctx, insn, check_reg(rd) || check_reg(rm));
+}
+
+static void
+emit_div(struct a64_jit_ctx *ctx, bool is64, uint8_t rd, uint8_t rm)
+{
+ emit_data_process_two_src(ctx, is64, rd, rd, rm, A64_UDIV);
+}
+
+static void
+emit_msub(struct a64_jit_ctx *ctx, bool is64, uint8_t rd, uint8_t rn,
+ uint8_t rm, uint8_t ra)
+{
+ uint32_t insn;
+
+ insn = (!!is64) << 31;
+ insn |= 0xd8 << 21;
+ insn |= rm << 16;
+ insn |= 0x1 << 15;
+ insn |= ra << 10;
+ insn |= rn << 5;
+ insn |= rd;
+
+ emit_insn(ctx, insn, check_reg(rd) || check_reg(rn) || check_reg(rm) ||
+ check_reg(ra));
+}
+
+static void
+emit_mod(struct a64_jit_ctx *ctx, bool is64, uint8_t tmp, uint8_t rd,
+ uint8_t rm)
+{
+ emit_data_process_two_src(ctx, is64, tmp, rd, rm, A64_UDIV);
+ emit_msub(ctx, is64, rd, tmp, rm, rd);
+}
+
static uint8_t
ebpf_to_a64_reg(struct a64_jit_ctx *ctx, uint8_t reg)
{
@@ -365,6 +549,44 @@ emit_epilogue(struct a64_jit_ctx *ctx)
emit_epilogue_no_call(ctx);
}
+static void
+emit_cbnz(struct a64_jit_ctx *ctx, bool is64, uint8_t rt, int32_t imm19)
+{
+ uint32_t insn, imm;
+
+ imm = mask_imm(19, imm19);
+ insn = (!!is64) << 31;
+ insn |= 0x35 << 24;
+ insn |= imm << 5;
+ insn |= rt;
+
+ emit_insn(ctx, insn, check_reg(rt) || check_imm(19, imm19));
+}
+
+static void
+emit_b(struct a64_jit_ctx *ctx, int32_t imm26)
+{
+ uint32_t insn, imm;
+
+ imm = mask_imm(26, imm26);
+ insn = 0x5 << 26;
+ insn |= imm;
+
+ emit_insn(ctx, insn, check_imm(26, imm26));
+}
+
+static void
+emit_return_zero_if_src_zero(struct a64_jit_ctx *ctx, bool is64, uint8_t src)
+{
+ uint8_t r0 = ebpf_to_a64_reg(ctx, EBPF_REG_0);
+ uint16_t jump_to_epilogue;
+
+ emit_cbnz(ctx, is64, src, 3);
+ emit_mov_imm(ctx, is64, r0, 0);
+ jump_to_epilogue = (ctx->program_start + ctx->program_sz) - ctx->idx;
+ emit_b(ctx, jump_to_epilogue);
+}
+
static void
check_program_has_call(struct a64_jit_ctx *ctx, struct rte_bpf *bpf)
{
@@ -391,15 +613,19 @@ check_program_has_call(struct a64_jit_ctx *ctx, struct rte_bpf *bpf)
static int
emit(struct a64_jit_ctx *ctx, struct rte_bpf *bpf)
{
- uint8_t op;
+ uint8_t op, dst, src, tmp1, tmp2;
const struct ebpf_insn *ins;
+ int32_t imm;
uint32_t i;
+ bool is64;
int rc;
/* Reset context fields */
ctx->idx = 0;
/* arm64 SP must be aligned to 16 */
ctx->stack_sz = RTE_ALIGN_MUL_CEIL(bpf->stack_sz, 16);
+ tmp1 = ebpf_to_a64_reg(ctx, TMP_REG_1);
+ tmp2 = ebpf_to_a64_reg(ctx, TMP_REG_2);
emit_prologue(ctx);
@@ -407,8 +633,80 @@ emit(struct a64_jit_ctx *ctx, struct rte_bpf *bpf)
ins = bpf->prm.ins + i;
op = ins->code;
+ imm = ins->imm;
+
+ dst = ebpf_to_a64_reg(ctx, ins->dst_reg);
+ src = ebpf_to_a64_reg(ctx, ins->src_reg);
+ is64 = (BPF_CLASS(op) == EBPF_ALU64);
switch (op) {
+ /* dst = src */
+ case (BPF_ALU | EBPF_MOV | BPF_X):
+ case (EBPF_ALU64 | EBPF_MOV | BPF_X):
+ emit_mov(ctx, is64, dst, src);
+ break;
+ /* dst = imm */
+ case (BPF_ALU | EBPF_MOV | BPF_K):
+ case (EBPF_ALU64 | EBPF_MOV | BPF_K):
+ emit_mov_imm(ctx, is64, dst, imm);
+ break;
+ /* dst += src */
+ case (BPF_ALU | BPF_ADD | BPF_X):
+ case (EBPF_ALU64 | BPF_ADD | BPF_X):
+ emit_add(ctx, is64, dst, src);
+ break;
+ /* dst += imm */
+ case (BPF_ALU | BPF_ADD | BPF_K):
+ case (EBPF_ALU64 | BPF_ADD | BPF_K):
+ emit_mov_imm(ctx, is64, tmp1, imm);
+ emit_add(ctx, is64, dst, tmp1);
+ break;
+ /* dst -= src */
+ case (BPF_ALU | BPF_SUB | BPF_X):
+ case (EBPF_ALU64 | BPF_SUB | BPF_X):
+ emit_sub(ctx, is64, dst, src);
+ break;
+ /* dst -= imm */
+ case (BPF_ALU | BPF_SUB | BPF_K):
+ case (EBPF_ALU64 | BPF_SUB | BPF_K):
+ emit_mov_imm(ctx, is64, tmp1, imm);
+ emit_sub(ctx, is64, dst, tmp1);
+ break;
+ /* dst *= src */
+ case (BPF_ALU | BPF_MUL | BPF_X):
+ case (EBPF_ALU64 | BPF_MUL | BPF_X):
+ emit_mul(ctx, is64, dst, src);
+ break;
+ /* dst *= imm */
+ case (BPF_ALU | BPF_MUL | BPF_K):
+ case (EBPF_ALU64 | BPF_MUL | BPF_K):
+ emit_mov_imm(ctx, is64, tmp1, imm);
+ emit_mul(ctx, is64, dst, tmp1);
+ break;
+ /* dst /= src */
+ case (BPF_ALU | BPF_DIV | BPF_X):
+ case (EBPF_ALU64 | BPF_DIV | BPF_X):
+ emit_return_zero_if_src_zero(ctx, is64, src);
+ emit_div(ctx, is64, dst, src);
+ break;
+ /* dst /= imm */
+ case (BPF_ALU | BPF_DIV | BPF_K):
+ case (EBPF_ALU64 | BPF_DIV | BPF_K):
+ emit_mov_imm(ctx, is64, tmp1, imm);
+ emit_div(ctx, is64, dst, tmp1);
+ break;
+ /* dst %= src */
+ case (BPF_ALU | BPF_MOD | BPF_X):
+ case (EBPF_ALU64 | BPF_MOD | BPF_X):
+ emit_return_zero_if_src_zero(ctx, is64, src);
+ emit_mod(ctx, is64, tmp1, dst, src);
+ break;
+ /* dst %= imm */
+ case (BPF_ALU | BPF_MOD | BPF_K):
+ case (EBPF_ALU64 | BPF_MOD | BPF_K):
+ emit_mov_imm(ctx, is64, tmp1, imm);
+ emit_mod(ctx, is64, tmp2, dst, tmp1);
+ break;
/* Return r0 */
case (BPF_JMP | EBPF_EXIT):
emit_epilogue(ctx);
--
2.23.0
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