ppc: propagate the calling conventions change down to csum_partial_copy_generic()

... and get rid of the pointless fallback in the wrappers.  On error it used
to zero the unwritten area and calculate the csum of the entire thing.  Not
wanting to do it in assembler part had been very reasonable; doing that in
the first place, OTOH...  In case of an error the caller discards the data
we'd copied, along with whatever checksum it might've had.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 27 insertions, 47 deletions

diff --git a/arch/powerpc/lib/checksum_32.S b/arch/powerpc/lib/checksum_32.S
index ecd150dc3ed9..ec5cd2dede35 100644
--- a/arch/powerpc/lib/checksum_32.S
+++ b/arch/powerpc/lib/checksum_32.S
@@ -78,12 +78,10 @@ EXPORT_SYMBOL(__csum_partial)
 
 /*
  * Computes the checksum of a memory block at src, length len,
- * and adds in "sum" (32-bit), while copying the block to dst.
- * If an access exception occurs on src or dst, it stores -EFAULT
- * to *src_err or *dst_err respectively, and (for an error on
- * src) zeroes the rest of dst.
+ * and adds in 0xffffffff, while copying the block to dst.
+ * If an access exception occurs it returns zero.
  *
- * csum_partial_copy_generic(src, dst, len, sum, src_err, dst_err)
+ * csum_partial_copy_generic(src, dst, len)
  */
 #define CSUM_COPY_16_BYTES_WITHEX(n)	\
 8 ## n ## 0:			\
@@ -108,14 +106,14 @@ EXPORT_SYMBOL(__csum_partial)
 	adde	r12,r12,r10
 
 #define CSUM_COPY_16_BYTES_EXCODE(n)		\
-	EX_TABLE(8 ## n ## 0b, src_error);	\
-	EX_TABLE(8 ## n ## 1b, src_error);	\
-	EX_TABLE(8 ## n ## 2b, src_error);	\
-	EX_TABLE(8 ## n ## 3b, src_error);	\
-	EX_TABLE(8 ## n ## 4b, dst_error);	\
-	EX_TABLE(8 ## n ## 5b, dst_error);	\
-	EX_TABLE(8 ## n ## 6b, dst_error);	\
-	EX_TABLE(8 ## n ## 7b, dst_error);
+	EX_TABLE(8 ## n ## 0b, fault);	\
+	EX_TABLE(8 ## n ## 1b, fault);	\
+	EX_TABLE(8 ## n ## 2b, fault);	\
+	EX_TABLE(8 ## n ## 3b, fault);	\
+	EX_TABLE(8 ## n ## 4b, fault);	\
+	EX_TABLE(8 ## n ## 5b, fault);	\
+	EX_TABLE(8 ## n ## 6b, fault);	\
+	EX_TABLE(8 ## n ## 7b, fault);
 
 	.text
 	.stabs	"arch/powerpc/lib/",N_SO,0,0,0f
@@ -127,11 +125,8 @@ LG_CACHELINE_BYTES = L1_CACHE_SHIFT
 CACHELINE_MASK = (L1_CACHE_BYTES-1)
 
 _GLOBAL(csum_partial_copy_generic)
-	stwu	r1,-16(r1)
-	stw	r7,12(r1)
-	stw	r8,8(r1)
-
-	addic	r12,r6,0
+	li	r12,-1
+	addic	r0,r0,0			/* clear carry */
 	addi	r6,r4,-4
 	neg	r0,r4
 	addi	r4,r3,-4
@@ -246,34 +241,19 @@ _GLOBAL(csum_partial_copy_generic)
 	rlwinm	r3,r3,8,0,31	/* odd destination address: rotate one byte */
 	blr
 
-/* read fault */
-src_error:
-	lwz	r7,12(r1)
-	addi	r1,r1,16
-	cmpwi	cr0,r7,0
-	beqlr
-	li	r0,-EFAULT
-	stw	r0,0(r7)
-	blr
-/* write fault */
-dst_error:
-	lwz	r8,8(r1)
-	addi	r1,r1,16
-	cmpwi	cr0,r8,0
-	beqlr
-	li	r0,-EFAULT
-	stw	r0,0(r8)
+fault:
+	li	r3,0
 	blr
 
-	EX_TABLE(70b, src_error);
-	EX_TABLE(71b, dst_error);
-	EX_TABLE(72b, src_error);
-	EX_TABLE(73b, dst_error);
-	EX_TABLE(54b, dst_error);
+	EX_TABLE(70b, fault);
+	EX_TABLE(71b, fault);
+	EX_TABLE(72b, fault);
+	EX_TABLE(73b, fault);
+	EX_TABLE(54b, fault);
 
 /*
  * this stuff handles faults in the cacheline loop and branches to either
- * src_error (if in read part) or dst_error (if in write part)
+ * fault (if in read part) or fault (if in write part)
  */
 	CSUM_COPY_16_BYTES_EXCODE(0)
 #if L1_CACHE_BYTES >= 32
@@ -290,12 +270,12 @@ dst_error:
 #endif
 #endif
 
-	EX_TABLE(30b, src_error);
-	EX_TABLE(31b, dst_error);
-	EX_TABLE(40b, src_error);
-	EX_TABLE(41b, dst_error);
-	EX_TABLE(50b, src_error);
-	EX_TABLE(51b, dst_error);
+	EX_TABLE(30b, fault);
+	EX_TABLE(31b, fault);
+	EX_TABLE(40b, fault);
+	EX_TABLE(41b, fault);
+	EX_TABLE(50b, fault);
+	EX_TABLE(51b, fault);
 
 EXPORT_SYMBOL(csum_partial_copy_generic)