nfp: bpf: move translation prepare to offload.c

struct nfp_prog is currently only used internally by the translator.
This means there is a lot of parameter passing going on, between
the translator and different stages of offload.  Simplify things
by allocating nfp_prog in offload.c already.

We will now use kmalloc() to allocate the program area and only
DMA map it for the time of loading (instead of allocating DMA
coherent memory upfront).

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 87 insertions, 41 deletions

diff --git a/drivers/net/ethernet/netronome/nfp/bpf/offload.c b/drivers/net/ethernet/netronome/nfp/bpf/offload.c
index 3eeee200051e..c5546c0e87d8 100644
--- a/drivers/net/ethernet/netronome/nfp/bpf/offload.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/offload.c
@@ -51,7 +51,7 @@
 #include "../nfp_net_ctrl.h"
 #include "../nfp_net.h"
 
-int
+static int
 nfp_prog_prepare(struct nfp_prog *nfp_prog, const struct bpf_insn *prog,
 		 unsigned int cnt)
 {
@@ -73,7 +73,7 @@ nfp_prog_prepare(struct nfp_prog *nfp_prog, const struct bpf_insn *prog,
 	return 0;
 }
 
-void nfp_prog_free(struct nfp_prog *nfp_prog)
+static void nfp_prog_free(struct nfp_prog *nfp_prog)
 {
 	struct nfp_insn_meta *meta, *tmp;
 
@@ -84,25 +84,36 @@ void nfp_prog_free(struct nfp_prog *nfp_prog)
 	kfree(nfp_prog);
 }
 
-static int
-nfp_net_bpf_offload_prepare(struct nfp_net *nn, struct bpf_prog *prog,
-			    struct nfp_bpf_result *res,
-			    void **code, dma_addr_t *dma_addr, u16 max_instr)
+static struct nfp_prog *nfp_bpf_verifier_prep(struct bpf_prog *prog)
 {
-	unsigned int code_sz = max_instr * sizeof(u64);
-	unsigned int stack_size;
-	u16 start_off, done_off;
-	unsigned int max_mtu;
+	struct nfp_prog *nfp_prog;
 	int ret;
 
-	max_mtu = nn_readb(nn, NFP_NET_CFG_BPF_INL_MTU) * 64 - 32;
-	if (max_mtu < nn->dp.netdev->mtu) {
-		nn_info(nn, "BPF offload not supported with MTU larger than HW packet split boundary\n");
-		return -EOPNOTSUPP;
-	}
+	nfp_prog = kzalloc(sizeof(*nfp_prog), GFP_KERNEL);
+	if (!nfp_prog)
+		return NULL;
+
+	INIT_LIST_HEAD(&nfp_prog->insns);
+	nfp_prog->type = prog->type;
 
-	start_off = nn_readw(nn, NFP_NET_CFG_BPF_START);
-	done_off = nn_readw(nn, NFP_NET_CFG_BPF_DONE);
+	ret = nfp_prog_prepare(nfp_prog, prog->insnsi, prog->len);
+	if (ret)
+		goto err_free;
+
+	return nfp_prog;
+
+err_free:
+	nfp_prog_free(nfp_prog);
+
+	return NULL;
+}
+
+static int
+nfp_bpf_translate(struct nfp_net *nn, struct nfp_prog *nfp_prog,
+		  struct bpf_prog *prog)
+{
+	unsigned int stack_size;
+	unsigned int max_instr;
 
 	stack_size = nn_readb(nn, NFP_NET_CFG_BPF_STACK_SZ) * 64;
 	if (prog->aux->stack_depth > stack_size) {
@@ -111,28 +122,68 @@ nfp_net_bpf_offload_prepare(struct nfp_net *nn, struct bpf_prog *prog,
 		return -EOPNOTSUPP;
 	}
 
-	*code = dma_zalloc_coherent(nn->dp.dev, code_sz, dma_addr, GFP_KERNEL);
-	if (!*code)
+	nfp_prog->stack_depth = prog->aux->stack_depth;
+	nfp_prog->start_off = nn_readw(nn, NFP_NET_CFG_BPF_START);
+	nfp_prog->tgt_done = nn_readw(nn, NFP_NET_CFG_BPF_DONE);
+
+	max_instr = nn_readw(nn, NFP_NET_CFG_BPF_MAX_LEN);
+	nfp_prog->__prog_alloc_len = max_instr * sizeof(u64);
+
+	nfp_prog->prog = kmalloc(nfp_prog->__prog_alloc_len, GFP_KERNEL);
+	if (!nfp_prog->prog)
 		return -ENOMEM;
 
-	ret = nfp_bpf_jit(prog, *code, start_off, done_off, max_instr, res);
-	if (ret)
-		goto out;
+	return nfp_bpf_jit(nfp_prog, prog);
+}
+
+static void nfp_bpf_destroy(struct nfp_prog *nfp_prog)
+{
+	kfree(nfp_prog->prog);
+	nfp_prog_free(nfp_prog);
+}
+
+static struct nfp_prog *
+nfp_net_bpf_offload_prepare(struct nfp_net *nn, struct bpf_prog *prog,
+			    dma_addr_t *dma_addr)
+{
+	struct nfp_prog *nfp_prog;
+	unsigned int max_mtu;
+	int err;
+
+	max_mtu = nn_readb(nn, NFP_NET_CFG_BPF_INL_MTU) * 64 - 32;
+	if (max_mtu < nn->dp.netdev->mtu) {
+		nn_info(nn, "BPF offload not supported with MTU larger than HW packet split boundary\n");
+		return NULL;
+	}
+
+	nfp_prog = nfp_bpf_verifier_prep(prog);
+	if (!nfp_prog)
+		return NULL;
+
+	err = nfp_bpf_translate(nn, nfp_prog, prog);
+	if (err)
+		goto err_destroy_prog;
+
+	*dma_addr = dma_map_single(nn->dp.dev, nfp_prog->prog,
+				   nfp_prog->prog_len * sizeof(u64),
+				   DMA_TO_DEVICE);
+	if (dma_mapping_error(nn->dp.dev, *dma_addr))
+		goto err_destroy_prog;
 
 	return 0;
 
-out:
-	dma_free_coherent(nn->dp.dev, code_sz, *code, *dma_addr);
-	return ret;
+err_destroy_prog:
+	nfp_bpf_destroy(nfp_prog);
+	return NULL;
 }
 
 static void
-nfp_net_bpf_load(struct nfp_net *nn, void *code, dma_addr_t dma_addr,
-		 unsigned int code_sz, unsigned int n_instr)
+nfp_net_bpf_load(struct nfp_net *nn, struct nfp_prog *nfp_prog,
+		 dma_addr_t dma_addr)
 {
 	int err;
 
-	nn_writew(nn, NFP_NET_CFG_BPF_SIZE, n_instr);
+	nn_writew(nn, NFP_NET_CFG_BPF_SIZE, nfp_prog->prog_len);
 	nn_writeq(nn, NFP_NET_CFG_BPF_ADDR, dma_addr);
 
 	/* Load up the JITed code */
@@ -140,7 +191,9 @@ nfp_net_bpf_load(struct nfp_net *nn, void *code, dma_addr_t dma_addr,
 	if (err)
 		nn_err(nn, "FW command error while loading BPF: %d\n", err);
 
-	dma_free_coherent(nn->dp.dev, code_sz, code, dma_addr);
+	dma_unmap_single(nn->dp.dev, dma_addr, nfp_prog->prog_len * sizeof(u64),
+			 DMA_TO_DEVICE);
+	nfp_bpf_destroy(nfp_prog);
 }
 
 static void nfp_net_bpf_start(struct nfp_net *nn)
@@ -169,11 +222,8 @@ static int nfp_net_bpf_stop(struct nfp_net *nn)
 int nfp_net_bpf_offload(struct nfp_net *nn, struct bpf_prog *prog,
 			bool old_prog)
 {
-	struct nfp_bpf_result res;
+	struct nfp_prog *nfp_prog;
 	dma_addr_t dma_addr;
-	u16 max_instr;
-	void *code;
-	int err;
 
 	if (prog && old_prog) {
 		u8 cap;
@@ -192,15 +242,11 @@ int nfp_net_bpf_offload(struct nfp_net *nn, struct bpf_prog *prog,
 	if (old_prog && !prog)
 		return nfp_net_bpf_stop(nn);
 
-	max_instr = nn_readw(nn, NFP_NET_CFG_BPF_MAX_LEN);
-
-	err = nfp_net_bpf_offload_prepare(nn, prog, &res, &code, &dma_addr,
-					  max_instr);
-	if (err)
-		return err;
+	nfp_prog = nfp_net_bpf_offload_prepare(nn, prog, &dma_addr);
+	if (!nfp_prog)
+		return -EINVAL;
 
-	nfp_net_bpf_load(nn, code, dma_addr, max_instr * sizeof(u64),
-			 res.n_instr);
+	nfp_net_bpf_load(nn, nfp_prog, dma_addr);
 	if (!old_prog)
 		nfp_net_bpf_start(nn);