nfp: bpf: pad code with valid nops

We need to append up to 8 nops after last instruction to make
sure the CPU will not fetch garbage instructions with invalid
ECC if the code store was not initialized.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jakub Kicinski 2017-10-08 21:04:15 -07:00 committed by David S. Miller
parent fd068ddc88
commit 1c03e03f9b
2 changed files with 13 additions and 1 deletions

View file

@ -426,6 +426,11 @@ emit_ld_field(struct nfp_prog *nfp_prog, swreg dst, u8 bmask, swreg src,
emit_ld_field_any(nfp_prog, sc, shift, dst, bmask, src, 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);
}
/* --- Wrappers --- */
static bool pack_immed(u32 imm, u16 *val, enum immed_shift *shift)
{
@ -1550,7 +1555,7 @@ static void nfp_outro(struct nfp_prog *nfp_prog)
static int nfp_translate(struct nfp_prog *nfp_prog)
{
struct nfp_insn_meta *meta;
int err;
int i, err;
nfp_intro(nfp_prog);
if (nfp_prog->error)
@ -1582,6 +1587,11 @@ static int nfp_translate(struct nfp_prog *nfp_prog)
if (nfp_prog->error)
return nfp_prog->error;
for (i = 0; i < NFP_USTORE_PREFETCH_WINDOW; i++)
emit_nop(nfp_prog);
if (nfp_prog->error)
return nfp_prog->error;
return nfp_fixup_branches(nfp_prog);
}

View file

@ -362,6 +362,8 @@ int swreg_to_unrestricted(swreg dst, swreg lreg, swreg rreg,
int swreg_to_restricted(swreg dst, swreg lreg, swreg rreg,
struct nfp_insn_re_regs *reg, bool has_imm8);
#define NFP_USTORE_PREFETCH_WINDOW 8
int nfp_ustore_check_valid_no_ecc(u64 insn);
u64 nfp_ustore_calc_ecc_insn(u64 insn);