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>
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index b7212b6..b94740f 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -154,7 +154,8 @@
arch/powerpc/lib/ \
arch/powerpc/sysdev/ \
arch/powerpc/platforms/ \
- arch/powerpc/math-emu/
+ arch/powerpc/math-emu/ \
+ arch/powerpc/net/
core-$(CONFIG_XMON) += arch/powerpc/xmon/
core-$(CONFIG_KVM) += arch/powerpc/kvm/