kernel/linux.git/arch/powerpc/include/asm/checksum.h, branch linux-4.16.y

powerpc/64: Fix checksum folding in csum_add()

2017-03-04T12:07:17+00:00

Paul's patch to fix checksum folding, commit b492f7e4e07a ("powerpc/64: Fix checksum folding in csum_tcpudp_nofold and ip_fast_csum_nofold") missed a case in csum_add(). Fix it. Signed-off-by: Shile Zhang Acked-by: Paul Mackerras Signed-off-by: Michael Ellerman

powerpc/64: Use optimized checksum routines on little-endian

2017-01-25T02:34:18+00:00

Currently we have optimized hand-coded assembly checksum routines for big-endian 64-bit systems, but for little-endian we use the generic C routines. This modifies the optimized routines to work for little-endian. With this, we no longer need to enable CONFIG_GENERIC_CSUM. This also fixes a couple of comments in checksum_64.S so they accurately reflect what the associated instruction does. Signed-off-by: Paul Mackerras [mpe: Use the more common __BIG_ENDIAN__] Signed-off-by: Michael Ellerman

powerpc/64: Fix checksum folding in csum_tcpudp_nofold and ip_fast_csum_nofold

2017-01-25T02:34:18+00:00

These functions compute an IP checksum by computing a 64-bit sum and folding it to 32 bits (the "nofold" in their names refers to folding down to 16 bits). However, doing (u32) (s + (s >> 32)) is not sufficient to fold a 64-bit sum to 32 bits correctly. The addition can produce a carry out from bit 31, which needs to be added in to the sum to produce the correct result. To fix this, we copy the from64to32() function from lib/checksum.c and use that. Signed-off-by: Paul Mackerras Signed-off-by: Michael Ellerman

arch/powerpc: Update parameters for csum_tcpudp_magic & csum_tcpudp_nofold

2016-10-29T21:06:23+00:00

Commit 01cfbad "ipv4: Update parameters for csum_tcpudp_magic to their original types" changed parameters for csum_tcpudp_magic and csum_tcpudp_nofold for many platforms but not for PowerPC. Fixes: 01cfbad "ipv4: Update parameters for csum_tcpudp_magic to their original types" Cc: Alexander Duyck Signed-off-by: Ivan Vecera Acked-by: Alexander Duyck Signed-off-by: David S. Miller

powerpc: optimise csum_partial() call when len is constant

2016-03-09T16:44:18+00:00

csum_partial is often called for small fixed length packets for which it is suboptimal to use the generic csum_partial() function. For instance, in my configuration, I got: * One place calling it with constant len 4 * Seven places calling it with constant len 8 * Three places calling it with constant len 14 * One place calling it with constant len 20 * One place calling it with constant len 24 * One place calling it with constant len 32 This patch renames csum_partial() to __csum_partial() and implements csum_partial() as a wrapper inline function which * uses csum_add() for small 16bits multiple constant length * uses ip_fast_csum() for other 32bits multiple constant * uses __csum_partial() in all other cases Signed-off-by: Christophe Leroy Signed-off-by: Scott Wood

powerpc: simplify csum_add(a, b) in case a or b is constant 0

2016-03-05T05:04:00+00:00

Simplify csum_add(a, b) in case a or b is constant 0 Signed-off-by: Christophe Leroy Signed-off-by: Scott Wood

powerpc: inline ip_fast_csum()

2016-03-05T03:49:49+00:00

In several architectures, ip_fast_csum() is inlined There are functions like ip_send_check() which do nothing much more than calling ip_fast_csum(). Inlining ip_fast_csum() allows the compiler to optimise better Suggested-by: Eric Dumazet Signed-off-by: Christophe Leroy [scottwood: whitespace and cast fixes] Signed-off-by: Scott Wood

powerpc32: checksum_wrappers_64 becomes checksum_wrappers

2016-03-05T03:47:47+00:00

The powerpc64 checksum wrapper functions adds csum_and_copy_to_user() which otherwise is implemented in include/net/checksum.h by using csum_partial() then copy_to_user() Those two wrapper fonctions are also applicable to powerpc32 as it is based on the use of csum_partial_copy_generic() which also exists on powerpc32 This patch renames arch/powerpc/lib/checksum_wrappers_64.c to arch/powerpc/lib/checksum_wrappers.c and makes it non-conditional to CONFIG_WORD_SIZE Signed-off-by: Christophe Leroy Signed-off-by: Scott Wood

powerpc: mark xer clobbered in csum_add()

2016-03-05T03:47:27+00:00

addc uses carry so xer is clobbered in csum_add() Signed-off-by: Christophe Leroy Signed-off-by: Scott Wood

powerpc: add support for csum_add()

2015-08-08T03:59:19+00:00

The C version of csum_add() as defined in include/net/checksum.h gives the following assembly in ppc32: 0: 7c 04 1a 14 add r0,r4,r3 4: 7c 64 00 10 subfc r3,r4,r0 8: 7c 63 19 10 subfe r3,r3,r3 c: 7c 63 00 50 subf r3,r3,r0 and the following in ppc64: 0xc000000000001af8 <+0>: add r3,r3,r4 0xc000000000001afc <+4>: cmplw cr7,r3,r4 0xc000000000001b00 <+8>: mfcr r4 0xc000000000001b04 <+12>: rlwinm r4,r4,29,31,31 0xc000000000001b08 <+16>: add r3,r4,r3 0xc000000000001b0c <+20>: clrldi r3,r3,32 0xc000000000001b10 <+24>: blr include/net/checksum.h also offers the possibility to define an arch specific function. This patch provides a specific csum_add() inline function. Signed-off-by: Christophe Leroy Signed-off-by: Scott Wood