The rotr, seh and wsbh instructions have been introduced with the R2
ISA. Thus the current BPF code fails to build on pre-R2 little endian
CPUs:
CC arch/mips/net/bpf_jit.o
AS arch/mips/net/bpf_jit_asm.o
/home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S: Assembler messages:
/home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:67: Error: opcode not supported on this processor: mips32 (mips32) `wsbh $8,$19'
/home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:68: Error: opcode not supported on this processor: mips32 (mips32) `rotr $19,$8,16'
/home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:83: Error: opcode not supported on this processor: mips32 (mips32) `wsbh $8,$19'
/home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:84: Error: opcode not supported on this processor: mips32 (mips32) `seh $19,$8'
/home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:151: Error: opcode not supported on this processor: mips32 (mips32) `wsbh $8,$12'
/home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:153: Error: opcode not supported on this processor: mips32 (mips32) `rotr $19,$8,16'
/home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:164: Error: opcode not supported on this processor: mips32 (mips32) `wsbh $19,$12'
/home/aurel32/linux-4.2/scripts/Makefile.build:294: recipe for target 'arch/mips/net/bpf_jit_asm.o' failed
Fix that by providing equivalent code for these CPUs.
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: Markos Chandras <markos.chandras@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v4.2+
Signed-off-by: Aurelien Jarno <aurelien@xxxxxxxxxxx>
---
arch/mips/net/bpf_jit_asm.S | 42 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 42 insertions(+)
diff --git a/arch/mips/net/bpf_jit_asm.S b/arch/mips/net/bpf_jit_asm.S
index 4f54cb1..dabf417 100644
--- a/arch/mips/net/bpf_jit_asm.S
+++ b/arch/mips/net/bpf_jit_asm.S
@@ -64,8 +64,20 @@ sk_load_word_positive:
PTR_ADDU t1, $r_skb_data, offset
lw $r_A, 0(t1)
#ifdef CONFIG_CPU_LITTLE_ENDIAN
+# if defined(__mips_isa_rev) && (__mips_isa_rev >= 2)
wsbh t0, $r_A
rotr $r_A, t0, 16
+# else
+ sll t0, $r_A, 24
+ srl t1, $r_A, 24
+ srl t2, $r_A, 8
+ or t0, t0, t1
+ andi t2, t2, 0xff00
+ andi t1, $r_A, 0xff00
+ or t0, t0, t2
+ sll t1, t1, 8
+ or $r_A, t0, t1
+# endif
#endif
jr $r_ra
move $r_ret, zero
@@ -80,8 +92,16 @@ sk_load_half_positive:
PTR_ADDU t1, $r_skb_data, offset
lh $r_A, 0(t1)
#ifdef CONFIG_CPU_LITTLE_ENDIAN
+# if defined(__mips_isa_rev) && (__mips_isa_rev >= 2)
wsbh t0, $r_A
seh $r_A, t0
+# else
+ sll t0, $r_A, 24
+ andi t1, $r_A, 0xff00
+ sra t0, t0, 16
+ srl t1, t1, 8
+ or $r_A, t0, t1
+# endif
#endif
jr $r_ra
move $r_ret, zero
@@ -148,9 +168,22 @@ sk_load_byte_positive:
NESTED(bpf_slow_path_word, (6 * SZREG), $r_sp)
bpf_slow_path_common(4)
#ifdef CONFIG_CPU_LITTLE_ENDIAN
+# if defined(__mips_isa_rev) && (__mips_isa_rev >= 2)
wsbh t0, $r_s0
jr $r_ra
rotr $r_A, t0, 16
+# else
+ sll t0, $r_s0, 24
+ srl t1, $r_s0, 24
+ srl t2, $r_s0, 8
+ or t0, t0, t1
+ andi t2, t2, 0xff00
+ andi t1, $r_s0, 0xff00
+ or t0, t0, t2
+ sll t1, t1, 8
+ jr $r_ra
+ or $r_A, t0, t1
+# endif
#else
jr $r_ra
move $r_A, $r_s0
@@ -161,8 +194,17 @@ NESTED(bpf_slow_path_word, (6 * SZREG), $r_sp)
NESTED(bpf_slow_path_half, (6 * SZREG), $r_sp)
bpf_slow_path_common(2)
#ifdef CONFIG_CPU_LITTLE_ENDIAN
+# if defined(__mips_isa_rev) && (__mips_isa_rev >= 2)
jr $r_ra
wsbh $r_A, $r_s0
+# else
+ sll t0, $r_s0, 8
+ andi t1, $r_s0, 0xff00
+ andi t0, t0, 0xff00
+ srl t1, t1, 8
+ jr $r_ra
+ or $r_A, t0, t1
+# endif
#else
jr $r_ra
move $r_A, $r_s0
--
2.1.4
