From: Jakub Kicinski <jakub.kicinski@netronome.com>
To: alexei.starovoitov@gmail.com, daniel@iogearbox.net, davem@davemloft.net
Cc: netdev@vger.kernel.org, oss-drivers@netronome.com,
tehnerd@fb.com, Jakub Kicinski <jakub.kicinski@netronome.com>
Subject: [PATCH bpf-next v2 12/15] nfp: bpf: add helpers for updating immediate instructions
Date: Thu, 11 Jan 2018 20:29:14 -0800 [thread overview]
Message-ID: <20180112042917.10348-13-jakub.kicinski@netronome.com> (raw)
In-Reply-To: <20180112042917.10348-1-jakub.kicinski@netronome.com>
Immediate loads are used to load the return address of a helper.
We need to be able to update those loads for relocations.
Immediate loads can be slightly more complex and spread over
two instructions in general, but here we only care about simple
loads of small (< 65k) constants, so complex cases are not handled.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
---
drivers/net/ethernet/netronome/nfp/nfp_asm.c | 58 ++++++++++++++++++++++++++++
drivers/net/ethernet/netronome/nfp/nfp_asm.h | 4 ++
2 files changed, 62 insertions(+)
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_asm.c b/drivers/net/ethernet/netronome/nfp/nfp_asm.c
index 9ee3a3f60cc7..3f6952b66a49 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_asm.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_asm.c
@@ -50,6 +50,11 @@ const struct cmd_tgt_act cmd_tgt_act[__CMD_TGT_MAP_SIZE] = {
[CMD_TGT_READ_SWAP_LE] = { 0x03, 0x40 },
};
+static bool unreg_is_imm(u16 reg)
+{
+ return (reg & UR_REG_IMM) == UR_REG_IMM;
+}
+
u16 br_get_offset(u64 instr)
{
u16 addr_lo, addr_hi;
@@ -80,6 +85,59 @@ void br_add_offset(u64 *instr, u16 offset)
br_set_offset(instr, addr + offset);
}
+static bool immed_can_modify(u64 instr)
+{
+ if (FIELD_GET(OP_IMMED_INV, instr) ||
+ FIELD_GET(OP_IMMED_SHIFT, instr) ||
+ FIELD_GET(OP_IMMED_WIDTH, instr) != IMMED_WIDTH_ALL) {
+ pr_err("Can't decode/encode immed!\n");
+ return false;
+ }
+ return true;
+}
+
+u16 immed_get_value(u64 instr)
+{
+ u16 reg;
+
+ if (!immed_can_modify(instr))
+ return 0;
+
+ reg = FIELD_GET(OP_IMMED_A_SRC, instr);
+ if (!unreg_is_imm(reg))
+ reg = FIELD_GET(OP_IMMED_B_SRC, instr);
+
+ return (reg & 0xff) | FIELD_GET(OP_IMMED_IMM, instr);
+}
+
+void immed_set_value(u64 *instr, u16 immed)
+{
+ if (!immed_can_modify(*instr))
+ return;
+
+ if (unreg_is_imm(FIELD_GET(OP_IMMED_A_SRC, *instr))) {
+ *instr &= ~FIELD_PREP(OP_IMMED_A_SRC, 0xff);
+ *instr |= FIELD_PREP(OP_IMMED_A_SRC, immed & 0xff);
+ } else {
+ *instr &= ~FIELD_PREP(OP_IMMED_B_SRC, 0xff);
+ *instr |= FIELD_PREP(OP_IMMED_B_SRC, immed & 0xff);
+ }
+
+ *instr &= ~OP_IMMED_IMM;
+ *instr |= FIELD_PREP(OP_IMMED_IMM, immed >> 8);
+}
+
+void immed_add_value(u64 *instr, u16 offset)
+{
+ u16 val;
+
+ if (!immed_can_modify(*instr))
+ return;
+
+ val = immed_get_value(*instr);
+ immed_set_value(instr, val + 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 20e51cb60e69..5f9291db98e0 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_asm.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_asm.h
@@ -138,6 +138,10 @@ enum immed_shift {
IMMED_SHIFT_2B = 2,
};
+u16 immed_get_value(u64 instr);
+void immed_set_value(u64 *instr, u16 immed);
+void immed_add_value(u64 *instr, u16 offset);
+
#define OP_SHF_BASE 0x08000000000ULL
#define OP_SHF_A_SRC 0x000000000ffULL
#define OP_SHF_SC 0x00000000300ULL
--
2.15.1
next prev parent reply other threads:[~2018-01-12 4:29 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-12 4:29 [PATCH bpf-next v2 00/15] bpf: support creating maps on networking devices Jakub Kicinski
2018-01-12 4:29 ` [PATCH bpf-next v2 01/15] bpf: add map_alloc_check callback Jakub Kicinski
2018-01-12 4:29 ` [PATCH bpf-next v2 02/15] bpf: hashtab: move attribute validation before allocation Jakub Kicinski
2018-01-12 4:29 ` [PATCH bpf-next v2 03/15] bpf: hashtab: move checks out of alloc function Jakub Kicinski
2018-01-12 4:29 ` [PATCH bpf-next v2 04/15] bpf: add helper for copying attrs to struct bpf_map Jakub Kicinski
2018-01-12 4:29 ` [PATCH bpf-next v2 05/15] bpf: rename bpf_dev_offload -> bpf_prog_offload Jakub Kicinski
2018-01-12 4:29 ` [PATCH bpf-next v2 06/15] bpf: offload: factor out netdev checking at allocation time Jakub Kicinski
2018-01-12 4:29 ` [PATCH bpf-next v2 07/15] bpf: offload: add map offload infrastructure Jakub Kicinski
2018-01-14 23:37 ` Daniel Borkmann
2018-01-14 23:52 ` Jakub Kicinski
2018-01-14 23:58 ` Daniel Borkmann
2018-01-12 4:29 ` [PATCH bpf-next v2 08/15] nfp: bpf: add map data structure Jakub Kicinski
2018-01-12 4:29 ` [PATCH bpf-next v2 09/15] nfp: bpf: add basic control channel communication Jakub Kicinski
2018-01-12 4:29 ` [PATCH bpf-next v2 10/15] nfp: bpf: implement helpers for FW map ops Jakub Kicinski
2018-01-12 4:29 ` [PATCH bpf-next v2 11/15] nfp: bpf: parse function call and map capabilities Jakub Kicinski
2018-01-12 4:29 ` Jakub Kicinski [this message]
2018-01-12 4:29 ` [PATCH bpf-next v2 13/15] nfp: bpf: add verification and codegen for map lookups Jakub Kicinski
2018-01-12 4:29 ` [PATCH bpf-next v2 14/15] nfp: bpf: add support for reading map memory Jakub Kicinski
2018-01-12 4:29 ` [PATCH bpf-next v2 15/15] nfp: bpf: implement bpf map offload Jakub Kicinski
2018-01-15 0:00 ` [PATCH bpf-next v2 00/15] bpf: support creating maps on networking devices Daniel Borkmann
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