[PATCH] RAID6 Altivec fix

This patch fixes a signedness bug with RAID6 for Altivec, and makes the
Altivec code testable in userspace.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/md/raid6.h

@@ -69,9 +69,13 @@ extern const char raid6_empty_zero_page[PAGE_SIZE];
 #define __init
 #define __exit
 #define __attribute_const__ __attribute__((const))
+#define noinline __attribute__((noinline))
 
 #define preempt_enable()
 #define preempt_disable()
+#define cpu_has_feature(x) 1
+#define enable_kernel_altivec()
+#define disable_kernel_altivec()
 
 #endif /* __KERNEL__ */
 

drivers/md/raid6algos.c

@@ -19,6 +19,7 @@
 #include "raid6.h"
 #ifndef __KERNEL__
 #include <sys/mman.h>
+#include <stdio.h>
 #endif
 
 struct raid6_calls raid6_call;

drivers/md/raid6altivec.uc

@@ -27,16 +27,20 @@
 #ifdef CONFIG_ALTIVEC
 
 #include <altivec.h>
-#include <asm/system.h>
-#include <asm/cputable.h>
+#ifdef __KERNEL__
+# include <asm/system.h>
+# include <asm/cputable.h>
+#endif
 
 /*
- * This is the C data type to use
+ * This is the C data type to use.  We use a vector of
+ * signed char so vec_cmpgt() will generate the right
+ * instruction.
  */
 
-typedef vector unsigned char unative_t;
+typedef vector signed char unative_t;
 
-#define NBYTES(x) ((vector unsigned char) {x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x})
+#define NBYTES(x) ((vector signed char) {x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x})
 #define NSIZE	sizeof(unative_t)
 
 /*
@@ -108,7 +112,11 @@ int raid6_have_altivec(void);
 int raid6_have_altivec(void)
 {
 	/* This assumes either all CPUs have Altivec or none does */
+# ifdef __KERNEL__
 	return cpu_has_feature(CPU_FTR_ALTIVEC);
+# else
+	return 1;
+# endif
 }
 #endif
 

drivers/md/raid6test/Makefile

@@ -8,6 +8,8 @@ OPTFLAGS = -O2			# Adjust as desired
 CFLAGS	 = -I.. -g $(OPTFLAGS)
 LD	 = ld
 PERL	 = perl
+AR	 = ar
+RANLIB	 = ranlib
 
 .c.o:
 	$(CC) $(CFLAGS) -c -o $@ $<
@@ -18,18 +20,33 @@ PERL	 = perl
 %.uc: ../%.uc
 	cp -f $< $@
 
-all:	raid6.o raid6test
+all:	raid6.a raid6test
 
-raid6.o: raid6int1.o raid6int2.o raid6int4.o raid6int8.o raid6int16.o \
+raid6.a: raid6int1.o raid6int2.o raid6int4.o raid6int8.o raid6int16.o \
 	 raid6int32.o \
 	 raid6mmx.o raid6sse1.o raid6sse2.o \
+	 raid6altivec1.o raid6altivec2.o raid6altivec4.o raid6altivec8.o \
 	 raid6recov.o raid6algos.o \
 	 raid6tables.o
-	$(LD) -r -o $@ $^
+	 rm -f $@
+	 $(AR) cq $@ $^
+	 $(RANLIB) $@
 
-raid6test: raid6.o test.c
+raid6test: test.c raid6.a
 	$(CC) $(CFLAGS) -o raid6test $^
 
+raid6altivec1.c: raid6altivec.uc ../unroll.pl
+	$(PERL) ../unroll.pl 1 < raid6altivec.uc > $@
+
+raid6altivec2.c: raid6altivec.uc ../unroll.pl
+	$(PERL) ../unroll.pl 2 < raid6altivec.uc > $@
+
+raid6altivec4.c: raid6altivec.uc ../unroll.pl
+	$(PERL) ../unroll.pl 4 < raid6altivec.uc > $@
+
+raid6altivec8.c: raid6altivec.uc ../unroll.pl
+	$(PERL) ../unroll.pl 8 < raid6altivec.uc > $@
+
 raid6int1.c: raid6int.uc ../unroll.pl
 	$(PERL) ../unroll.pl 1 < raid6int.uc > $@
 
@@ -52,7 +69,7 @@ raid6tables.c: mktables
 	./mktables > raid6tables.c
 
 clean:
-	rm -f *.o mktables mktables.c raid6int.uc raid6*.c raid6test
+	rm -f *.o *.a mktables mktables.c raid6int.uc raid6*.c raid6test
 
 spotless: clean
 	rm -f *~