mips, bpf: Enable eBPF JITs

This patch enables the new eBPF JITs for 32-bit and 64-bit MIPS. It also
disables the old cBPF JIT to so cBPF programs are converted to use the
new JIT.

Workarounds for R4000 CPU errata are not implemented by the JIT, so the
JIT is disabled if any of those workarounds are configured.

Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211005165408.2305108-7-johan.almbladh@anyfinetworks.com

MAINTAINERS

@@ -3422,6 +3422,7 @@ S:	Supported
 F:	arch/arm64/net/
 
 BPF JIT for MIPS (32-BIT AND 64-BIT)
+M:	Johan Almbladh <johan.almbladh@anyfinetworks.com>
 M:	Paul Burton <paulburton@kernel.org>
 L:	netdev@vger.kernel.org
 L:	bpf@vger.kernel.org

arch/mips/Kconfig

@@ -57,15 +57,17 @@ config MIPS
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if CPU_SUPPORTS_HUGEPAGES
 	select HAVE_ASM_MODVERSIONS
-	select HAVE_CBPF_JIT if !64BIT && !CPU_MICROMIPS
 	select HAVE_CONTEXT_TRACKING
 	select HAVE_TIF_NOHZ
 	select HAVE_C_RECORDMCOUNT
 	select HAVE_DEBUG_KMEMLEAK
 	select HAVE_DEBUG_STACKOVERFLOW
 	select HAVE_DMA_CONTIGUOUS
 	select HAVE_DYNAMIC_FTRACE
-	select HAVE_EBPF_JIT if 64BIT && !CPU_MICROMIPS && TARGET_ISA_REV >= 2
+	select HAVE_EBPF_JIT if !CPU_MICROMIPS && \
+				!CPU_DADDI_WORKAROUNDS && \
+				!CPU_R4000_WORKAROUNDS && \
+				!CPU_R4400_WORKAROUNDS
 	select HAVE_EXIT_THREAD
 	select HAVE_FAST_GUP
 	select HAVE_FTRACE_MCOUNT_RECORD

arch/mips/net/Makefile

@@ -2,9 +2,10 @@
 # MIPS networking code
 
 obj-$(CONFIG_MIPS_CBPF_JIT) += bpf_jit.o bpf_jit_asm.o
+obj-$(CONFIG_MIPS_EBPF_JIT) += bpf_jit_comp.o
 
 ifeq ($(CONFIG_32BIT),y)
-        obj-$(CONFIG_MIPS_EBPF_JIT) += bpf_jit_comp.o bpf_jit_comp32.o
+        obj-$(CONFIG_MIPS_EBPF_JIT) += bpf_jit_comp32.o
 else
-        obj-$(CONFIG_MIPS_EBPF_JIT) += ebpf_jit.o
+        obj-$(CONFIG_MIPS_EBPF_JIT) += bpf_jit_comp64.o
 endif