Commit 328e7e487a46 ("powerpc: force inlining of csum_partial() to
avoid multiple csum_partial() with GCC10") inlined csum_partial().
Now that csum_partial() is inlined, GCC outlines csum_add() when
called by csum_partial().
c064fb28 <csum_add>:
c064fb28: 7c 63 20 14 addc r3,r3,r4
c064fb2c: 7c 63 01 94 addze r3,r3
c064fb30: 4e 80 00 20 blr
c0665fb8 <csum_add>:
c0665fb8: 7c 63 20 14 addc r3,r3,r4
c0665fbc: 7c 63 01 94 addze r3,r3
c0665fc0: 4e 80 00 20 blr
c066719c: 7c 9a c0 2e lwzx r4,r26,r24
c06671a0: 38 60 00 00 li r3,0
c06671a4: 7f 1a c2 14 add r24,r26,r24
c06671a8: 4b ff ee 11 bl c0665fb8 <csum_add>
c06671ac: 80 98 00 04 lwz r4,4(r24)
c06671b0: 4b ff ee 09 bl c0665fb8 <csum_add>
c06671b4: 80 98 00 08 lwz r4,8(r24)
c06671b8: 4b ff ee 01 bl c0665fb8 <csum_add>
c06671bc: a0 98 00 0c lhz r4,12(r24)
c06671c0: 4b ff ed f9 bl c0665fb8 <csum_add>
c06671c4: 7c 63 18 f8 not r3,r3
c06671c8: 81 3f 00 68 lwz r9,104(r31)
c06671cc: 81 5f 00 a0 lwz r10,160(r31)
c06671d0: 7d 29 18 14 addc r9,r9,r3
c06671d4: 7d 29 01 94 addze r9,r9
c06671d8: 91 3f 00 68 stw r9,104(r31)
c06671dc: 7d 1a 50 50 subf r8,r26,r10
c06671e0: 83 01 00 10 lwz r24,16(r1)
c06671e4: 83 41 00 18 lwz r26,24(r1)
The sum with 0 is useless, should have been skipped.
And there is even one completely unused instance of csum_add().
In file included from ./include/net/checksum.h:22,
from ./include/linux/skbuff.h:28,
from ./include/linux/icmp.h:16,
from net/ipv6/ip6_tunnel.c:23:
./arch/powerpc/include/asm/checksum.h: In function '__ip6_tnl_rcv':
./arch/powerpc/include/asm/checksum.h:94:22: warning: inlining failed in call
to 'csum_add': call is unlikely and code size would grow [-Winline]
94 | static inline __wsum csum_add(__wsum csum, __wsum addend)
| ^~~~~~~~
./arch/powerpc/include/asm/checksum.h:172:31: note: called from here
172 | sum = csum_add(sum, (__force __wsum)*(const u32
*)buff);
|
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
./arch/powerpc/include/asm/checksum.h:94:22: warning: inlining failed in call
to 'csum_add': call is unlikely and code size would grow [-Winline]
94 | static inline __wsum csum_add(__wsum csum, __wsum addend)
| ^~~~~~~~
./arch/powerpc/include/asm/checksum.h:177:31: note: called from here
177 | sum = csum_add(sum, (__force __wsum)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
178 | *(const u32 *)(buff + 4));
| ~~~~~~~~~~~~~~~~~~~~~~~~~
./arch/powerpc/include/asm/checksum.h:94:22: warning: inlining failed in call
to 'csum_add': call is unlikely and code size would grow [-Winline]
94 | static inline __wsum csum_add(__wsum csum, __wsum addend)
| ^~~~~~~~
./arch/powerpc/include/asm/checksum.h:183:31: note: called from here
183 | sum = csum_add(sum, (__force __wsum)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
184 | *(const u32 *)(buff + 8));
| ~~~~~~~~~~~~~~~~~~~~~~~~~
./arch/powerpc/include/asm/checksum.h:94:22: warning: inlining failed in call
to 'csum_add': call is unlikely and code size would grow [-Winline]
94 | static inline __wsum csum_add(__wsum csum, __wsum addend)
| ^~~~~~~~
./arch/powerpc/include/asm/checksum.h:186:31: note: called from here
186 | sum = csum_add(sum, (__force __wsum)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
187 | *(const u16 *)(buff + 12));
| ~~~~~~~~~~~~~~~~~~~~~~~~~~
Force inlining of csum_add().
94c: 80 df 00 a0 lwz r6,160(r31)
950: 7d 28 50 2e lwzx r9,r8,r10
954: 7d 48 52 14 add r10,r8,r10
958: 80 aa 00 04 lwz r5,4(r10)
95c: 80 ff 00 68 lwz r7,104(r31)
960: 7d 29 28 14 addc r9,r9,r5
964: 7d 29 01 94 addze r9,r9
968: 7d 08 30 50 subf r8,r8,r6
96c: 80 aa 00 08 lwz r5,8(r10)
970: a1 4a 00 0c lhz r10,12(r10)
974: 7d 29 28 14 addc r9,r9,r5
978: 7d 29 01 94 addze r9,r9
97c: 7d 29 50 14 addc r9,r9,r10
980: 7d 29 01 94 addze r9,r9
984: 7d 29 48 f8 not r9,r9
988: 7c e7 48 14 addc r7,r7,r9
98c: 7c e7 01 94 addze r7,r7
990: 90 ff 00 68 stw r7,104(r31)
In the non-inlined version, the first sum with 0 was performed.
Here it is skipped.
Signed-off-by: Christophe Leroy <christophe.le...@csgroup.eu>
---
arch/powerpc/include/asm/checksum.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/checksum.h
b/arch/powerpc/include/asm/checksum.h
index d5da7ddbf0fc..350de8f90250 100644
--- a/arch/powerpc/include/asm/checksum.h
+++ b/arch/powerpc/include/asm/checksum.h
@@ -91,7 +91,7 @@ static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32
daddr, __u32 len,
}
#define HAVE_ARCH_CSUM_ADD
-static inline __wsum csum_add(__wsum csum, __wsum addend)
+static __always_inline __wsum csum_add(__wsum csum, __wsum addend)
{
#ifdef __powerpc64__
u64 res = (__force u64)csum;
--
2.25.0
