From: Matt Evans Date: Wed, 20 Jul 2011 15:51:00 +0000 (+0000) Subject: net: filter: BPF 'JIT' compiler for PPC64 X-Git-Tag: v3.1-rc1~316^2~71 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0ca87f05ba8bdc6791c14878464efc901ad71e99;p=pandora-kernel.git 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 Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- Reading git-diff-tree failed