arm64: add missing conversion to __wsum in ip_fast_csum()
PATCH 1/1 arm64: add missing conversion to __wsum in ip_fast_csum()
ARM64 implementation of ip_fast_csum() do most of the work in 128 or 64 bit and call csum_fold() to finalize. csum_fold() itself take a __wsum argument, to insure that this value is always a 32bit native-order value.
Fix this by using an helper __csum_fold() taking the native 32 bit value and doing the needed folding to 16 bit (and reuse this helper for csum_fold() itself).
Note: a simpler patch would to use something like:
return csum_fold((__wsum __force)(sum >> 32));
but using an helper __csum_fold() allow to avoid a forced cast.
--- arch/arm64/include/asm/checksum.h | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
arch/arm64/include/asm/checksum.h +7 -3
@@ -18,12 +18,16 @@#include <linux/types.h> -static inline __sum16 csum_fold (__wsum csum) +static inline __sum16 __csum_fold (u32 sum) { -u32 sum = (__force u32 )csum; sum += (sum >>16 ) | (sum <<16 );return ~(__force __sum16)(sum >>16 ); } + +static inline __sum16 csum_fold (__wsum csum) +{ +return __csum_fold ((__force u32 )csum); +}#define csum_fold csum_foldstatic inline __sum16 ip_fast_csum (const void *iph,unsigned int ihl)
@@ -42,7 +46,7 @@ static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) }while (--ihl); sum += ((sum >>32 ) | (sum <<32 )); -return csum_fold (sum >>32 ); +return __csum_fold (sum >>32 ); }#define ip_fast_csum ip_fast_csum
Signature · 1 line
2.13.0
PATCH 1/1 arm64: add missing conversion to __wsum in ip_fast_csum()
Quoted 5 lines · Luc Van Oostenryck
ARM64 implementation of
ip_fast_csum()do most of the work in 128 or 64 bit and callcsum_fold()to finalize.csum_fold()itself take a__wsumargument, to insure that this value is always a 32bit native-order value.
Quoted 8 lines
Fix this by using an helper
__csum_fold()taking the native 32 bit value and doing the needed folding to 16 bit (and reuse this helper forcsum_fold()itself).Note: a simpler patch would to use something like:
returncsum_fold((__wsum __force)(sum >> 32));
but using an helper__csum_fold()allow to avoid a forced cast.
But you've added a __force cast in csum_fold, and we still have the one in the return statement of __csum_fold, so I think I prefer the simpler patch.
Will
Quoted 41 lines
Signed-off-by Luc Van Oostenryck <[email protected]>--- arch/arm64/include/asm/checksum.h | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)arch/arm64/include/asm/checksum.h +7
-3@@ -18,12 +18,16 @@#include <linux/types.h> -static inline __sum16 csum_fold (__wsum csum) +static inline __sum16 __csum_fold (u32 sum) { -u32 sum = (__force u32 )csum; sum += (sum >>16 ) | (sum <<16 );return ~(__force __sum16)(sum >>16 ); } + +static inline __sum16 csum_fold (__wsum csum) +{ +return __csum_fold ((__force u32 )csum); +}#define csum_fold csum_foldstatic inline __sum16 ip_fast_csum (const void *iph,unsigned int ihl)@@ -42,7 +46,7 @@ static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) }while (--ihl); sum += ((sum >>32 ) | (sum <<32 )); -return csum_fold (sum >>32 ); +return __csum_fold (sum >>32 ); }#define ip_fast_csum ip_fast_csumSignature · 1 line
2.13.0
PATCH v2 1/1 arm64: add missing conversion to __wsum in ip_fast_csum()
ARM64 implementation of ip_fast_csum() do most of the work in 128 or 64 bit and call csum_fold() to finalize. csum_fold() itself take a __wsum argument, to insure that this value is always a 32bit native-order value.
Fix this by adding the sadly needed '__force' to cast the native 'sum' to the type '__wsum'.
---
Change since v1:
- use the simple __force cast instead of an intermediate helper.
--- arch/arm64/include/asm/checksum.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
arch/arm64/include/asm/checksum.h +1 -1
@@ -42,7 +42,7 @@ static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) }while (--ihl); sum += ((sum >>32 ) | (sum <<32 )); -return csum_fold (sum >>32 ); +return csum_fold ((__force u32)(sum >>32 )); }#define ip_fast_csum ip_fast_csum
Signature · 1 line
2.13.0