]> git.karo-electronics.de Git - linux-beck.git/commit
net: filter: BPF 'JIT' compiler for PPC64
authorMatt Evans <matt@ozlabs.org>
Wed, 20 Jul 2011 15:51:00 +0000 (15:51 +0000)
committerDavid S. Miller <davem@davemloft.net>
Thu, 21 Jul 2011 19:38:32 +0000 (12:38 -0700)
commit0ca87f05ba8bdc6791c14878464efc901ad71e99
treec37e25b30c22adae633dcacb2236e83086887418
parent3aeb7d2243e55ddcad3c0b402e7b09619a67f5da
net: filter: BPF 'JIT' compiler for PPC64

An implementation of a code generator for BPF programs to speed up packet
filtering on PPC64, inspired by Eric Dumazet's x86-64 version.

Filter code is generated as an ABI-compliant function in module_alloc()'d mem
with stackframe & prologue/epilogue generated if required (simple filters don't
need anything more than an li/blr).  The filter's local variables, M[], live in
registers.  Supports all BPF opcodes, although "complicated" loads from negative
packet offsets (e.g. SKF_LL_OFF) are not yet supported.

There are a couple of further optimisations left for future work; many-pass
assembly with branch-reach reduction and a register allocator to push M[]
variables into volatile registers would improve the code quality further.

This currently supports big-endian 64-bit PowerPC only (but is fairly simple
to port to PPC32 or LE!).

Enabled in the same way as x86-64:

echo 1 > /proc/sys/net/core/bpf_jit_enable

Or, enabled with extra debug output:

echo 2 > /proc/sys/net/core/bpf_jit_enable

Signed-off-by: Matt Evans <matt@ozlabs.org>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
arch/powerpc/Kconfig
arch/powerpc/Makefile
arch/powerpc/include/asm/ppc-opcode.h
arch/powerpc/net/Makefile [new file with mode: 0644]
arch/powerpc/net/bpf_jit.h [new file with mode: 0644]
arch/powerpc/net/bpf_jit_64.S [new file with mode: 0644]
arch/powerpc/net/bpf_jit_comp.c [new file with mode: 0644]