[PATCH bpf-next 07/14] nfp: bpf: add helpers for modifying branch addresses

[Jakub Kicinski]

In preparation for better handling of relocations move existing
helper for setting branch offset to nfp_asm.c and add two more.

Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com>
Reviewed-by: Jiong Wang <jiong.w...@netronome.com>
---
 drivers/net/ethernet/netronome/nfp/bpf/jit.c | 12 -----------
 drivers/net/ethernet/netronome/nfp/nfp_asm.c | 30 ++++++++++++++++++++++++++++
 drivers/net/ethernet/netronome/nfp/nfp_asm.h |  4 ++++
 3 files changed, 34 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/bpf/jit.c 
b/drivers/net/ethernet/netronome/nfp/bpf/jit.c
index 9caff3a7505a..c5d1628a5414 100644
--- a/drivers/net/ethernet/netronome/nfp/bpf/jit.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/jit.c
@@ -2110,18 +2110,6 @@ static const instr_cb_t instr_cb[256] = {
        [BPF_JMP | BPF_EXIT] =          goto_out,
 };
 
-/* --- Misc code --- */
-static void br_set_offset(u64 *instr, u16 offset)
-{
-       u16 addr_lo, addr_hi;
-
-       addr_lo = offset & (OP_BR_ADDR_LO >> __bf_shf(OP_BR_ADDR_LO));
-       addr_hi = offset != addr_lo;
-       *instr &= ~(OP_BR_ADDR_HI | OP_BR_ADDR_LO);
-       *instr |= FIELD_PREP(OP_BR_ADDR_HI, addr_hi);
-       *instr |= FIELD_PREP(OP_BR_ADDR_LO, addr_lo);
-}
-
 /* --- Assembler logic --- */
 static int nfp_fixup_branches(struct nfp_prog *nfp_prog)
 {
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_asm.c 
b/drivers/net/ethernet/netronome/nfp/nfp_asm.c
index d3610987fb07..9ee3a3f60cc7 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_asm.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_asm.c
@@ -50,6 +50,36 @@ const struct cmd_tgt_act cmd_tgt_act[__CMD_TGT_MAP_SIZE] = {
        [CMD_TGT_READ_SWAP_LE] =        { 0x03, 0x40 },
 };
 
+u16 br_get_offset(u64 instr)
+{
+       u16 addr_lo, addr_hi;
+
+       addr_lo = FIELD_GET(OP_BR_ADDR_LO, instr);
+       addr_hi = FIELD_GET(OP_BR_ADDR_HI, instr);
+
+       return (addr_hi * ((OP_BR_ADDR_LO >> __bf_shf(OP_BR_ADDR_LO)) + 1)) |
+               addr_lo;
+}
+
+void br_set_offset(u64 *instr, u16 offset)
+{
+       u16 addr_lo, addr_hi;
+
+       addr_lo = offset & (OP_BR_ADDR_LO >> __bf_shf(OP_BR_ADDR_LO));
+       addr_hi = offset != addr_lo;
+       *instr &= ~(OP_BR_ADDR_HI | OP_BR_ADDR_LO);
+       *instr |= FIELD_PREP(OP_BR_ADDR_HI, addr_hi);
+       *instr |= FIELD_PREP(OP_BR_ADDR_LO, addr_lo);
+}
+
+void br_add_offset(u64 *instr, u16 offset)
+{
+       u16 addr;
+
+       addr = br_get_offset(*instr);
+       br_set_offset(instr, addr + offset);
+}
+
 static u16 nfp_swreg_to_unreg(swreg reg, bool is_dst)
 {
        bool lm_id, lm_dec = false;
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_asm.h 
b/drivers/net/ethernet/netronome/nfp/nfp_asm.h
index a24daeab1a77..a50240ab0ce2 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_asm.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_asm.h
@@ -93,6 +93,10 @@ enum br_ctx_signal_state {
        BR_CSS_NONE = 2,
 };
 
+u16 br_get_offset(u64 instr);
+void br_set_offset(u64 *instr, u16 offset);
+void br_add_offset(u64 *instr, u16 offset);
+
 #define OP_BBYTE_BASE          0x0c800000000ULL
 #define OP_BB_A_SRC            0x000000000ffULL
 #define OP_BB_BYTE             0x00000000300ULL
-- 
2.15.1