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

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 <paulus@ozlabs.org>
[mpe: Use the more common __BIG_ENDIAN__]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index a8ee573fe610bd5e2d8191b4dffb05e134a6d3c2..e022859340b75ff441bd887361575c056cb82018 100644 (file)
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -167,7 +167,7 @@ config PPC
        select HAVE_CC_STACKPROTECTOR
 
 config GENERIC_CSUM
-       def_bool CPU_LITTLE_ENDIAN
+       def_bool n
 
 config EARLY_PRINTK
        bool

diff --git a/arch/powerpc/include/asm/checksum.h b/arch/powerpc/include/asm/checksum.h
index 5b1a6e39afa7451a69cb4f7e83b3446cd09f4209..4e63787dc3becfd6c9b832f50a8c2e1367bd4187 100644 (file)
--- a/arch/powerpc/include/asm/checksum.h
+++ b/arch/powerpc/include/asm/checksum.h
@@ -70,7 +70,11 @@ static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len,
 
        s += (__force u32)saddr;
        s += (__force u32)daddr;
+#ifdef __BIG_ENDIAN__
        s += proto + len;
+#else
+       s += (proto + len) << 8;
+#endif
        return (__force __wsum) from64to32(s);
 #else
     __asm__("\n\

diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index 309361e8652331b65e9bc2d28b870f9791b6d986..0e649d72fe8d0d3a95f5b1c5216e4bf6f2a4bdd2 100644 (file)
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -21,9 +21,7 @@ obj64-y       += copypage_64.o copyuser_64.o usercopy_64.o mem_64.o hweight_64.o \
 obj64-$(CONFIG_SMP)    += locks.o
 obj64-$(CONFIG_ALTIVEC)        += vmx-helper.o
 
-ifeq ($(CONFIG_GENERIC_CSUM),)
 obj-y                  += checksum_$(BITS).o checksum_wrappers.o
-endif
 
 obj-$(CONFIG_PPC_EMULATE_SSTEP)        += sstep.o ldstfp.o
 

diff --git a/arch/powerpc/lib/checksum_64.S b/arch/powerpc/lib/checksum_64.S
index d0d311e108ffe0269e81e2254e182508c8363efb..d7f1a966136ea7e128c7ba85dc6b203d7bac27eb 100644 (file)
--- a/arch/powerpc/lib/checksum_64.S
+++ b/arch/powerpc/lib/checksum_64.S
@@ -36,7 +36,7 @@ _GLOBAL(__csum_partial)
         * work to calculate the correct checksum, we ignore that case
         * and take the potential slowdown of unaligned loads.
         */
-       rldicl. r6,r3,64-1,64-2         /* r6 = (r3 & 0x3) >> 1 */
+       rldicl. r6,r3,64-1,64-2         /* r6 = (r3 >> 1) & 0x3 */
        beq     .Lcsum_aligned
 
        li      r7,4
@@ -168,8 +168,12 @@ _GLOBAL(__csum_partial)
        beq     .Lcsum_finish
 
        lbz     r6,0(r3)
+#ifdef __BIG_ENDIAN__
        sldi    r9,r6,8                 /* Pad the byte out to 16 bits */
        adde    r0,r0,r9
+#else
+       adde    r0,r0,r6
+#endif
 
 .Lcsum_finish:
        addze   r0,r0                   /* add in final carry */
@@ -224,7 +228,7 @@ _GLOBAL(csum_partial_copy_generic)
         * If the source and destination are relatively unaligned we only
         * align the source. This keeps things simple.
         */
-       rldicl. r6,r3,64-1,64-2         /* r6 = (r3 & 0x3) >> 1 */
+       rldicl. r6,r3,64-1,64-2         /* r6 = (r3 >> 1) & 0x3 */
        beq     .Lcopy_aligned
 
        li      r9,4
@@ -386,8 +390,12 @@ dstnr;     sth     r6,0(r4)
        beq     .Lcopy_finish
 
 srcnr; lbz     r6,0(r3)
+#ifdef __BIG_ENDIAN__
        sldi    r9,r6,8                 /* Pad the byte out to 16 bits */
        adde    r0,r0,r9
+#else
+       adde    r0,r0,r6
+#endif
 dstnr; stb     r6,0(r4)
 
 .Lcopy_finish: