bpf, ppc64: implement jiting of BPF_J{LT, LE, SLT, SLE}

This work implements jiting of BPF_J{LT,LE,SLT,SLE} instructions
with BPF_X/BPF_K variants for the ppc64 eBPF JIT.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/powerpc/net/bpf_jit.h

@@ -263,6 +263,7 @@ static inline bool is_nearbranch(int offset)
 #define COND_EQ		(CR0_EQ | COND_CMP_TRUE)
 #define COND_NE		(CR0_EQ | COND_CMP_FALSE)
 #define COND_LT		(CR0_LT | COND_CMP_TRUE)
+#define COND_LE		(CR0_GT | COND_CMP_FALSE)
 
 #endif
 

arch/powerpc/net/bpf_jit_comp64.c

@@ -795,12 +795,24 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image,
 		case BPF_JMP | BPF_JSGT | BPF_X:
 			true_cond = COND_GT;
 			goto cond_branch;
+		case BPF_JMP | BPF_JLT | BPF_K:
+		case BPF_JMP | BPF_JLT | BPF_X:
+		case BPF_JMP | BPF_JSLT | BPF_K:
+		case BPF_JMP | BPF_JSLT | BPF_X:
+			true_cond = COND_LT;
+			goto cond_branch;
 		case BPF_JMP | BPF_JGE | BPF_K:
 		case BPF_JMP | BPF_JGE | BPF_X:
 		case BPF_JMP | BPF_JSGE | BPF_K:
 		case BPF_JMP | BPF_JSGE | BPF_X:
 			true_cond = COND_GE;
 			goto cond_branch;
+		case BPF_JMP | BPF_JLE | BPF_K:
+		case BPF_JMP | BPF_JLE | BPF_X:
+		case BPF_JMP | BPF_JSLE | BPF_K:
+		case BPF_JMP | BPF_JSLE | BPF_X:
+			true_cond = COND_LE;
+			goto cond_branch;
 		case BPF_JMP | BPF_JEQ | BPF_K:
 		case BPF_JMP | BPF_JEQ | BPF_X:
 			true_cond = COND_EQ;
@@ -817,14 +829,18 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image,
 cond_branch:
 			switch (code) {
 			case BPF_JMP | BPF_JGT | BPF_X:
+			case BPF_JMP | BPF_JLT | BPF_X:
 			case BPF_JMP | BPF_JGE | BPF_X:
+			case BPF_JMP | BPF_JLE | BPF_X:
 			case BPF_JMP | BPF_JEQ | BPF_X:
 			case BPF_JMP | BPF_JNE | BPF_X:
 				/* unsigned comparison */
 				PPC_CMPLD(dst_reg, src_reg);
 				break;
 			case BPF_JMP | BPF_JSGT | BPF_X:
+			case BPF_JMP | BPF_JSLT | BPF_X:
 			case BPF_JMP | BPF_JSGE | BPF_X:
+			case BPF_JMP | BPF_JSLE | BPF_X:
 				/* signed comparison */
 				PPC_CMPD(dst_reg, src_reg);
 				break;
@@ -834,7 +850,9 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image,
 			case BPF_JMP | BPF_JNE | BPF_K:
 			case BPF_JMP | BPF_JEQ | BPF_K:
 			case BPF_JMP | BPF_JGT | BPF_K:
+			case BPF_JMP | BPF_JLT | BPF_K:
 			case BPF_JMP | BPF_JGE | BPF_K:
+			case BPF_JMP | BPF_JLE | BPF_K:
 				/*
 				 * Need sign-extended load, so only positive
 				 * values can be used as imm in cmpldi
@@ -849,7 +867,9 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image,
 				}
 				break;
 			case BPF_JMP | BPF_JSGT | BPF_K:
+			case BPF_JMP | BPF_JSLT | BPF_K:
 			case BPF_JMP | BPF_JSGE | BPF_K:
+			case BPF_JMP | BPF_JSLE | BPF_K:
 				/*
 				 * signed comparison, so any 16-bit value
 				 * can be used in cmpdi