The cpuv4 added a new BPF_SDIV instruction that does signed division.
The encoding is similar to BPF_DIV but BPF_SDIV sets offset=1.

ARM32 already supports 32-bit BPF_DIV which can be easily extended to
support BPF_SDIV as ARM32 has the SDIV instruction. When the CPU is not
ARM-v7, we implement that SDIV/SMOD with the function call similar to
the implementation of DIV/MOD.
Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://lore.kernel.org/r/20230907230550.1417590-6-puranjay12@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>