bpf: split HAVE_BPF_JIT into cBPF and eBPF variant

Split the HAVE_BPF_JIT into two for distinguishing cBPF and eBPF JITs.

Current cBPF ones:

  # git grep -n HAVE_CBPF_JIT arch/
  arch/arm/Kconfig:44:    select HAVE_CBPF_JIT
  arch/mips/Kconfig:18:   select HAVE_CBPF_JIT if !CPU_MICROMIPS
  arch/powerpc/Kconfig:129:       select HAVE_CBPF_JIT
  arch/sparc/Kconfig:35:  select HAVE_CBPF_JIT

Current eBPF ones:

  # git grep -n HAVE_EBPF_JIT arch/
  arch/arm64/Kconfig:61:  select HAVE_EBPF_JIT
  arch/s390/Kconfig:126:  select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES
  arch/x86/Kconfig:94:    select HAVE_EBPF_JIT                    if X86_64

Later code also needs this facility to check for eBPF JITs.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/Kconfig b/net/Kconfig
index b841c42..f7148f2 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -289,7 +289,7 @@
 
 config BPF_JIT
 	bool "enable BPF Just In Time compiler"
-	depends on HAVE_BPF_JIT
+	depends on HAVE_CBPF_JIT || HAVE_EBPF_JIT
 	depends on MODULES
 	---help---
 	  Berkeley Packet Filter filtering capabilities are normally handled
@@ -419,6 +419,14 @@
 
 endif   # if NET
 
-# Used by archs to tell that they support BPF_JIT
-config HAVE_BPF_JIT
+# Used by archs to tell that they support BPF JIT compiler plus which flavour.
+# Only one of the two can be selected for a specific arch since eBPF JIT supersedes
+# the cBPF JIT.
+
+# Classic BPF JIT (cBPF)
+config HAVE_CBPF_JIT
+	bool
+
+# Extended BPF JIT (eBPF)
+config HAVE_EBPF_JIT
 	bool