From: Jakub Kicinski <jakub.kicinski@netronome.com>
Date: Wed, 28 Mar 2018 17:48:37 -0700
Subject: nfp: bpf: add support for bpf_get_prandom_u32()
Patch-mainline: v4.17-rc1
Git-commit: df4a37d8b53f9fb9af722b056da5edbd9a531768
References: bsc#1109837
NFP has a prng register, which we can read to obtain a u32 worth
of pseudo random data. Generate code for it.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/ethernet/netronome/nfp/bpf/fw.h | 1
drivers/net/ethernet/netronome/nfp/bpf/jit.c | 24 ++++++++++++++++++++--
drivers/net/ethernet/netronome/nfp/bpf/main.c | 12 +++++++++++
drivers/net/ethernet/netronome/nfp/bpf/main.h | 4 +++
drivers/net/ethernet/netronome/nfp/bpf/verifier.c | 7 ++++++
drivers/net/ethernet/netronome/nfp/nfp_asm.h | 1
6 files changed, 47 insertions(+), 2 deletions(-)
--- a/drivers/net/ethernet/netronome/nfp/bpf/fw.h
+++ b/drivers/net/ethernet/netronome/nfp/bpf/fw.h
@@ -41,6 +41,7 @@ enum bpf_cap_tlv_type {
NFP_BPF_CAP_TYPE_FUNC = 1,
NFP_BPF_CAP_TYPE_ADJUST_HEAD = 2,
NFP_BPF_CAP_TYPE_MAPS = 3,
+ NFP_BPF_CAP_TYPE_RANDOM = 4,
};
struct nfp_bpf_cap_tlv_func {
--- a/drivers/net/ethernet/netronome/nfp/bpf/jit.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/jit.c
@@ -407,7 +407,7 @@ __emit_lcsr(struct nfp_prog *nfp_prog, u
FIELD_PREP(OP_LCSR_A_SRC, areg) |
FIELD_PREP(OP_LCSR_B_SRC, breg) |
FIELD_PREP(OP_LCSR_WRITE, wr) |
- FIELD_PREP(OP_LCSR_ADDR, addr) |
+ FIELD_PREP(OP_LCSR_ADDR, addr / 4) |
FIELD_PREP(OP_LCSR_SRC_LMEXTN, src_lmextn) |
FIELD_PREP(OP_LCSR_DST_LMEXTN, dst_lmextn);
@@ -435,10 +435,16 @@ static void emit_csr_wr(struct nfp_prog
return;
}
- __emit_lcsr(nfp_prog, reg.areg, reg.breg, true, addr / 4,
+ __emit_lcsr(nfp_prog, reg.areg, reg.breg, true, addr,
false, reg.src_lmextn);
}
+/* CSR value is read in following immed[gpr, 0] */
+static void __emit_csr_rd(struct nfp_prog *nfp_prog, u16 addr)
+{
+ __emit_lcsr(nfp_prog, 0, 0, false, addr, false, false);
+}
+
static void emit_nop(struct nfp_prog *nfp_prog)
{
__emit_immed(nfp_prog, UR_REG_IMM, UR_REG_IMM, 0, 0, 0, 0, 0, 0, 0);
@@ -1400,6 +1406,18 @@ map_call_stack_common(struct nfp_prog *n
return 0;
}
+static int
+nfp_get_prandom_u32(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
+{
+ __emit_csr_rd(nfp_prog, NFP_CSR_PSEUDO_RND_NUM);
+ /* CSR value is read in following immed[gpr, 0] */
+ emit_immed(nfp_prog, reg_both(0), 0,
+ IMMED_WIDTH_ALL, false, IMMED_SHIFT_0B);
+ emit_immed(nfp_prog, reg_both(1), 0,
+ IMMED_WIDTH_ALL, false, IMMED_SHIFT_0B);
+ return 0;
+}
+
/* --- Callbacks --- */
static int mov_reg64(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
@@ -2433,6 +2451,8 @@ static int call(struct nfp_prog *nfp_pro
case BPF_FUNC_map_update_elem:
case BPF_FUNC_map_delete_elem:
return map_call_stack_common(nfp_prog, meta);
+ case BPF_FUNC_get_prandom_u32:
+ return nfp_get_prandom_u32(nfp_prog, meta);
default:
WARN_ONCE(1, "verifier allowed unsupported function\n");
return -EOPNOTSUPP;
--- a/drivers/net/ethernet/netronome/nfp/bpf/main.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/main.c
@@ -315,6 +315,14 @@ nfp_bpf_parse_cap_maps(struct nfp_app_bp
return 0;
}
+static int
+nfp_bpf_parse_cap_random(struct nfp_app_bpf *bpf, void __iomem *value,
+ u32 length)
+{
+ bpf->pseudo_random = true;
+ return 0;
+}
+
static int nfp_bpf_parse_capabilities(struct nfp_app *app)
{
struct nfp_cpp *cpp = app->pf->cpp;
@@ -353,6 +361,10 @@ static int nfp_bpf_parse_capabilities(st
if (nfp_bpf_parse_cap_maps(app->priv, value, length))
goto err_release_free;
break;
+ case NFP_BPF_CAP_TYPE_RANDOM:
+ if (nfp_bpf_parse_cap_random(app->priv, value, length))
+ goto err_release_free;
+ break;
default:
nfp_dbg(cpp, "unknown BPF capability: %d\n", type);
break;
--- a/drivers/net/ethernet/netronome/nfp/bpf/main.h
+++ b/drivers/net/ethernet/netronome/nfp/bpf/main.h
@@ -133,6 +133,8 @@ enum pkt_vec {
* @helpers.map_lookup: map lookup helper address
* @helpers.map_update: map update helper address
* @helpers.map_delete: map delete helper address
+ *
+ * @pseudo_random: FW initialized the pseudo-random machinery (CSRs)
*/
struct nfp_app_bpf {
struct nfp_app *app;
@@ -170,6 +172,8 @@ struct nfp_app_bpf {
u32 map_update;
u32 map_delete;
} helpers;
+
+ bool pseudo_random;
};
enum nfp_bpf_map_use {
--- a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c
@@ -209,6 +209,13 @@ nfp_bpf_check_call(struct nfp_prog *nfp_
meta->func_id ? &meta->arg2 : NULL))
return -EOPNOTSUPP;
break;
+
+ case BPF_FUNC_get_prandom_u32:
+ if (bpf->pseudo_random)
+ break;
+ pr_vlog(env, "bpf_get_prandom_u32(): FW doesn't support random number generation\n");
+ return -EOPNOTSUPP;
+
default:
pr_vlog(env, "unsupported function id: %d\n", func_id);
return -EOPNOTSUPP;
--- a/drivers/net/ethernet/netronome/nfp/nfp_asm.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_asm.h
@@ -284,6 +284,7 @@ enum lcsr_wr_src {
#define NFP_CSR_ACT_LM_ADDR1 0x6c
#define NFP_CSR_ACT_LM_ADDR2 0x94
#define NFP_CSR_ACT_LM_ADDR3 0x9c
+#define NFP_CSR_PSEUDO_RND_NUM 0x148
/* Software register representation, independent of operand type */
#define NN_REG_TYPE GENMASK(31, 24)