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authorAurelien Jarno <aurelien@aurel32.net>2015-09-05 18:46:57 +0200
committerRalf Baechle <ralf@linux-mips.org>2015-09-22 19:05:17 +0200
commitb259e51f2e29390518021f9b8df55a3de42f371b (patch)
tree32f1e90749e9f2617805135817321f11b6bc640d
parentMIPS: BPF: Avoid unreachable code on little endian (diff)
downloadlinux-b259e51f2e29390518021f9b8df55a3de42f371b.tar.xz
linux-b259e51f2e29390518021f9b8df55a3de42f371b.zip
MIPS: BPF: Fix build on pre-R2 little endian CPUs
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. Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> Reviewed-by: Markos Chandras <markos.chandras@imgtec.com> Cc: stable@vger.kernel.org # v4.2+ Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/11098/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
-rw-r--r--arch/mips/net/bpf_jit_asm.S42
1 files changed, 42 insertions, 0 deletions
diff --git a/arch/mips/net/bpf_jit_asm.S b/arch/mips/net/bpf_jit_asm.S
index 4f54cb18f104..dabf4179cd7e 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