Re: [PATCH bpf-next v2] m68k, bpf: Add initial BPF JIT compiler support

[Daniel Palmer]

Hi Kuan-Wei,

On Mon, 4 May 2026 at 03:15, Kuan-Wei Chiu <visitorckw@xxxxxxxxx> wrote:
>
> Add a BPF JIT compiler for the m68k architecture.
>
> The JIT generates m68k machine code targeting m68020+ processors. It
> currently excludes 68000/68010 and coldfire processors, as it relies on
> 32 bit branch displacements (b<cc>.l) to handle large bpf programs.
>
> Tested with the test_bpf.ko:
> test_bpf: Summary: 1053 PASSED, 0 FAILED, [1041/1041 JIT'ed]
> test_bpf: test_tail_calls: Summary: 10 PASSED, 0 FAILED, [10/10 JIT'ed]

Results match on a real 68040 (Apple Macintosh LC475, 1993 vintage):

test_bpf: Summary: 1053 PASSED, 0 FAILED, [1041/1041 JIT'ed]
test_bpf: test_tail_calls: Summary: 10 PASSED, 0 FAILED, [10/10 JIT'ed]
test_bpf: test_skb_segment: Summary: 2 PASSED, 0 FAILED
# uname -a
Linux buildroot 7.1.0-rc1-multi-00465-g1f6c5a18ddbd #26 Tue May  5
12:25:51 JST 2026 m68k GNU/Linux
# cat /proc/cpuinfo
CPU:            68040
MMU:            68040
FPU:            68040
Clocking:       32.3MHz
BogoMips:       21.55
Calibration:    107776 loops

Also the time the test took seems to be considerably shorter with JIT.

So:

Tested-by: Daniel Palmer <daniel@xxxxxxxxx>