diff mbox series

[net-next,06/15] nfp: bpf: remove register rename

Message ID 20171009040417.22172-7-jakub.kicinski@netronome.com
State Accepted, archived
Delegated to: David Miller
Headers show
Series nfp: bpf ABIv2 and multi port | expand

Commit Message

Jakub Kicinski Oct. 9, 2017, 4:04 a.m. UTC 
Remove the register renumbering optimization.  To implement calling
map and other helpers we need more strict register layout.  We can't
freely reassign register numbers.

This will have the effect of running in 4 context/thread mode, which
should be OK since we are moving towards integrating the BPF closer
with FW app datapath anyway, and the target datapath itself runs in
4 context mode.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
---
 drivers/net/ethernet/netronome/nfp/bpf/jit.c | 46 ++--------------------------
 1 file changed, 3 insertions(+), 43 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/netronome/nfp/bpf/jit.c b/drivers/net/ethernet/netronome/nfp/bpf/jit.c
index 095cf50e8450..469dc8a055f2 100644
--- a/drivers/net/ethernet/netronome/nfp/bpf/jit.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/jit.c
@@ -1621,38 +1621,6 @@  static void nfp_bpf_opt_reg_init(struct nfp_prog *nfp_prog)
 	}
 }
 
-/* Try to rename registers so that program uses only low ones */
-static int nfp_bpf_opt_reg_rename(struct nfp_prog *nfp_prog)
-{
-	bool reg_used[MAX_BPF_REG] = {};
-	u8 tgt_reg[MAX_BPF_REG] = {};
-	struct nfp_insn_meta *meta;
-	unsigned int i, j;
-
-	list_for_each_entry(meta, &nfp_prog->insns, l) {
-		if (meta->skip)
-			continue;
-
-		reg_used[meta->insn.src_reg] = true;
-		reg_used[meta->insn.dst_reg] = true;
-	}
-
-	for (i = 0, j = 0; i < ARRAY_SIZE(tgt_reg); i++) {
-		if (!reg_used[i])
-			continue;
-
-		tgt_reg[i] = j++;
-	}
-	nfp_prog->num_regs = j;
-
-	list_for_each_entry(meta, &nfp_prog->insns, l) {
-		meta->insn.src_reg = tgt_reg[meta->insn.src_reg];
-		meta->insn.dst_reg = tgt_reg[meta->insn.dst_reg];
-	}
-
-	return 0;
-}
-
 /* Remove masking after load since our load guarantees this is not needed */
 static void nfp_bpf_opt_ld_mask(struct nfp_prog *nfp_prog)
 {
@@ -1729,14 +1697,8 @@  static void nfp_bpf_opt_ld_shift(struct nfp_prog *nfp_prog)
 
 static int nfp_bpf_optimize(struct nfp_prog *nfp_prog)
 {
-	int ret;
-
 	nfp_bpf_opt_reg_init(nfp_prog);
 
-	ret = nfp_bpf_opt_reg_rename(nfp_prog);
-	if (ret)
-		return ret;
-
 	nfp_bpf_opt_ld_mask(nfp_prog);
 	nfp_bpf_opt_ld_shift(nfp_prog);
 
@@ -1783,10 +1745,8 @@  nfp_bpf_jit(struct bpf_prog *filter, void *prog_mem,
 	if (ret)
 		goto out;
 
-	if (nfp_prog->num_regs <= 7)
-		nfp_prog->regs_per_thread = 16;
-	else
-		nfp_prog->regs_per_thread = 32;
+	nfp_prog->num_regs = MAX_BPF_REG;
+	nfp_prog->regs_per_thread = 32;
 
 	nfp_prog->prog = prog_mem;
 	nfp_prog->__prog_alloc_len = prog_sz;
@@ -1799,7 +1759,7 @@  nfp_bpf_jit(struct bpf_prog *filter, void *prog_mem,
 	}
 
 	res->n_instr = nfp_prog->prog_len;
-	res->dense_mode = nfp_prog->num_regs <= 7;
+	res->dense_mode = false;
 out:
 	nfp_prog_free(nfp_prog);