[PATCH v3] net: filter: BPF 'JIT' compiler for PPC64
eric.dumazet at gmail.com
Thu Jul 21 15:00:19 EST 2011
Le jeudi 21 juillet 2011 à 11:51 +1000, Matt Evans a écrit :
> 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 at ozlabs.org>
> V3: Added BUILD_BUG_ON to assert PACA CPU ID is 16bits, made a comment (in
> LD_MSH) a bit clearer, ratelimited "Unknown opcode" error and moved
> bpf_jit.S to bpf_jit_64.S (it doesn't make sense to rename bpf_jit_comp.c as
> small portions will eventually get split out into _32/_64.c files when we do
> 32bit support).
> arch/powerpc/Kconfig | 1 +
> arch/powerpc/Makefile | 3 +-
> arch/powerpc/include/asm/ppc-opcode.h | 40 ++
> arch/powerpc/net/Makefile | 4 +
> arch/powerpc/net/bpf_jit.h | 227 +++++++++++
> arch/powerpc/net/bpf_jit_64.S | 138 +++++++
> arch/powerpc/net/bpf_jit_comp.c | 694 +++++++++++++++++++++++++++++++++
> 7 files changed, 1106 insertions(+), 1 deletions(-)
Nice work Matt ;)
Acked-by: Eric Dumazet <eric.dumazet at gmail.com>
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