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authorHassan Naveed <hnaveed@wavecomp.com>2019-03-12 22:48:06 +0000
committerPaul Burton <paul.burton@mips.com>2019-03-19 15:26:08 -0700
commit6c2c8a18886897226ee43e77c0149a8e1874274a (patch)
tree2abf18905b92953ba76ae86bff01f56357fa7b06
parent0d1d17b9ff8e7d69b2169337b263822355404a86 (diff)
MIPS: eBPF: Provide eBPF support for MIPS64R6
Currently eBPF support is available on MIPS64R2 only. Use MIPS64R6 variants of instructions like multiply, divide, movn, movz so eBPF can run on the newer ISA. Also, we only need to check ISA revision before JIT'ing code, because we know the CPU is running a 64-bit kernel because eBPF JIT is only included in kernels with CONFIG_64BIT=y due to Kconfig dependencies. Signed-off-by: Hassan Naveed <hnaveed@wavecomp.com> Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: kafai@fb.com Cc: songliubraving@fb.com Cc: yhs@fb.com Cc: netdev@vger.kernel.org Cc: bpf@vger.kernel.org Cc: linux-mips@vger.kernel.org Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: open list:MIPS <linux-mips@linux-mips.org> Cc: open list <linux-kernel@vger.kernel.org>
-rw-r--r--arch/mips/net/ebpf_jit.c78
1 files changed, 69 insertions, 9 deletions
diff --git a/arch/mips/net/ebpf_jit.c b/arch/mips/net/ebpf_jit.c
index 0effd3cba9a7..26eef9ad3896 100644
--- a/arch/mips/net/ebpf_jit.c
+++ b/arch/mips/net/ebpf_jit.c
@@ -22,6 +22,7 @@
#include <asm/byteorder.h>
#include <asm/cacheflush.h>
#include <asm/cpu-features.h>
+#include <asm/isa-rev.h>
#include <asm/uasm.h>
/* Registers used by JIT */
@@ -677,8 +678,12 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
if (insn->imm == 1) /* Mult by 1 is a nop */
break;
gen_imm_to_reg(insn, MIPS_R_AT, ctx);
- emit_instr(ctx, dmultu, MIPS_R_AT, dst);
- emit_instr(ctx, mflo, dst);
+ if (MIPS_ISA_REV >= 6) {
+ emit_instr(ctx, dmulu, dst, dst, MIPS_R_AT);
+ } else {
+ emit_instr(ctx, dmultu, MIPS_R_AT, dst);
+ emit_instr(ctx, mflo, dst);
+ }
break;
case BPF_ALU64 | BPF_NEG | BPF_K: /* ALU64_IMM */
dst = ebpf_to_mips_reg(ctx, insn, dst_reg);
@@ -700,8 +705,12 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
if (insn->imm == 1) /* Mult by 1 is a nop */
break;
gen_imm_to_reg(insn, MIPS_R_AT, ctx);
- emit_instr(ctx, multu, dst, MIPS_R_AT);
- emit_instr(ctx, mflo, dst);
+ if (MIPS_ISA_REV >= 6) {
+ emit_instr(ctx, mulu, dst, dst, MIPS_R_AT);
+ } else {
+ emit_instr(ctx, multu, dst, MIPS_R_AT);
+ emit_instr(ctx, mflo, dst);
+ }
break;
case BPF_ALU | BPF_NEG | BPF_K: /* ALU_IMM */
dst = ebpf_to_mips_reg(ctx, insn, dst_reg);
@@ -732,6 +741,13 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
break;
}
gen_imm_to_reg(insn, MIPS_R_AT, ctx);
+ if (MIPS_ISA_REV >= 6) {
+ if (bpf_op == BPF_DIV)
+ emit_instr(ctx, divu_r6, dst, dst, MIPS_R_AT);
+ else
+ emit_instr(ctx, modu, dst, dst, MIPS_R_AT);
+ break;
+ }
emit_instr(ctx, divu, dst, MIPS_R_AT);
if (bpf_op == BPF_DIV)
emit_instr(ctx, mflo, dst);
@@ -754,6 +770,13 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
break;
}
gen_imm_to_reg(insn, MIPS_R_AT, ctx);
+ if (MIPS_ISA_REV >= 6) {
+ if (bpf_op == BPF_DIV)
+ emit_instr(ctx, ddivu_r6, dst, dst, MIPS_R_AT);
+ else
+ emit_instr(ctx, modu, dst, dst, MIPS_R_AT);
+ break;
+ }
emit_instr(ctx, ddivu, dst, MIPS_R_AT);
if (bpf_op == BPF_DIV)
emit_instr(ctx, mflo, dst);
@@ -819,11 +842,23 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
emit_instr(ctx, and, dst, dst, src);
break;
case BPF_MUL:
- emit_instr(ctx, dmultu, dst, src);
- emit_instr(ctx, mflo, dst);
+ if (MIPS_ISA_REV >= 6) {
+ emit_instr(ctx, dmulu, dst, dst, src);
+ } else {
+ emit_instr(ctx, dmultu, dst, src);
+ emit_instr(ctx, mflo, dst);
+ }
break;
case BPF_DIV:
case BPF_MOD:
+ if (MIPS_ISA_REV >= 6) {
+ if (bpf_op == BPF_DIV)
+ emit_instr(ctx, ddivu_r6,
+ dst, dst, src);
+ else
+ emit_instr(ctx, modu, dst, dst, src);
+ break;
+ }
emit_instr(ctx, ddivu, dst, src);
if (bpf_op == BPF_DIV)
emit_instr(ctx, mflo, dst);
@@ -903,6 +938,13 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
break;
case BPF_DIV:
case BPF_MOD:
+ if (MIPS_ISA_REV >= 6) {
+ if (bpf_op == BPF_DIV)
+ emit_instr(ctx, divu_r6, dst, dst, src);
+ else
+ emit_instr(ctx, modu, dst, dst, src);
+ break;
+ }
emit_instr(ctx, divu, dst, src);
if (bpf_op == BPF_DIV)
emit_instr(ctx, mflo, dst);
@@ -1006,8 +1048,15 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
emit_instr(ctx, dsubu, MIPS_R_T8, dst, src);
emit_instr(ctx, sltu, MIPS_R_AT, dst, src);
/* SP known to be non-zero, movz becomes boolean not */
- emit_instr(ctx, movz, MIPS_R_T9, MIPS_R_SP, MIPS_R_T8);
- emit_instr(ctx, movn, MIPS_R_T9, MIPS_R_ZERO, MIPS_R_T8);
+ if (MIPS_ISA_REV >= 6) {
+ emit_instr(ctx, seleqz, MIPS_R_T9,
+ MIPS_R_SP, MIPS_R_T8);
+ } else {
+ emit_instr(ctx, movz, MIPS_R_T9,
+ MIPS_R_SP, MIPS_R_T8);
+ emit_instr(ctx, movn, MIPS_R_T9,
+ MIPS_R_ZERO, MIPS_R_T8);
+ }
emit_instr(ctx, or, MIPS_R_AT, MIPS_R_T9, MIPS_R_AT);
cmp_eq = bpf_op == BPF_JGT;
dst = MIPS_R_AT;
@@ -1366,6 +1415,17 @@ jeq_common:
if (src < 0)
return src;
if (BPF_MODE(insn->code) == BPF_XADD) {
+ /*
+ * If mem_off does not fit within the 9 bit ll/sc
+ * instruction immediate field, use a temp reg.
+ */
+ if (MIPS_ISA_REV >= 6 &&
+ (mem_off >= BIT(8) || mem_off < -BIT(8))) {
+ emit_instr(ctx, daddiu, MIPS_R_T6,
+ dst, mem_off);
+ mem_off = 0;
+ dst = MIPS_R_T6;
+ }
switch (BPF_SIZE(insn->code)) {
case BPF_W:
if (get_reg_val_type(ctx, this_idx, insn->src_reg) == REG_32BIT) {
@@ -1720,7 +1780,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
unsigned int image_size;
u8 *image_ptr;
- if (!prog->jit_requested || !cpu_has_mips64r2)
+ if (!prog->jit_requested || MIPS_ISA_REV < 2)
return prog;
tmp = bpf_jit_blind_constants(prog);