sparc64: Define SPARC default __fls function

__fls will now require a boot time patching on T4 and above.
Redefining it under arch/sparc/lib.

Signed-off-by: Vijay Kumar <vijay.ac.kumar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 63 insertions, 1 deletions

diff --git a/arch/sparc/include/asm/bitops_64.h b/arch/sparc/include/asm/bitops_64.h
index 30aea561176f..d7a46e2480c0 100644
--- a/arch/sparc/include/asm/bitops_64.h
+++ b/arch/sparc/include/asm/bitops_64.h
@@ -23,10 +23,10 @@ void clear_bit(unsigned long nr, volatile unsigned long *addr);
 void change_bit(unsigned long nr, volatile unsigned long *addr);
 
 int fls(unsigned int word);
+int __fls(unsigned long word);
 
 #include <asm-generic/bitops/non-atomic.h>
 
-#include <asm-generic/bitops/__fls.h>
 #include <asm-generic/bitops/fls64.h>
 
 #ifdef __KERNEL__
diff --git a/arch/sparc/lib/Makefile b/arch/sparc/lib/Makefile
index 3b9f5e0c1bcd..5380c5985420 100644
--- a/arch/sparc/lib/Makefile
+++ b/arch/sparc/lib/Makefile
@@ -17,6 +17,7 @@ lib-$(CONFIG_SPARC32) += lshrdi3.o ashldi3.o
 lib-$(CONFIG_SPARC32) += muldi3.o bitext.o cmpdi2.o
 lib-$(CONFIG_SPARC64) += multi3.o
 lib-$(CONFIG_SPARC64) += fls.o
+lib-$(CONFIG_SPARC64) += fls64.o
 
 lib-$(CONFIG_SPARC64) += copy_page.o clear_page.o bzero.o
 lib-$(CONFIG_SPARC64) += csum_copy.o csum_copy_from_user.o csum_copy_to_user.o
diff --git a/arch/sparc/lib/fls64.S b/arch/sparc/lib/fls64.S
new file mode 100644
index 000000000000..c83e22ae9586
--- /dev/null
+++ b/arch/sparc/lib/fls64.S
@@ -0,0 +1,61 @@
+/* fls64.S: SPARC default __fls definition.
+ *
+ * SPARC default __fls definition, which follows the same algorithm as
+ * in generic __fls(). This function will be boot time patched on T4
+ * and onward.
+ */
+
+#include <linux/linkage.h>
+#include <asm/export.h>
+
+        .text
+        .register       %g2, #scratch
+        .register       %g3, #scratch
+ENTRY(__fls)
+        mov     -1, %g2
+        sllx    %g2, 32, %g2
+        and     %o0, %g2, %g2
+        brnz,pt %g2, 1f
+         mov    63, %g1
+        sllx    %o0, 32, %o0
+        mov     31, %g1
+1:
+        mov     -1, %g2
+        sllx    %g2, 48, %g2
+        and     %o0, %g2, %g2
+        brnz,pt %g2, 2f
+         mov    -1, %g2
+        sllx    %o0, 16, %o0
+        add     %g1, -16, %g1
+2:
+        mov     -1, %g2
+        sllx    %g2, 56, %g2
+        and     %o0, %g2, %g2
+        brnz,pt %g2, 3f
+         mov    -1, %g2
+        sllx    %o0, 8, %o0
+        add     %g1, -8, %g1
+3:
+        sllx    %g2, 60, %g2
+        and     %o0, %g2, %g2
+        brnz,pt %g2, 4f
+         mov    -1, %g2
+        sllx    %o0, 4, %o0
+        add     %g1, -4, %g1
+4:
+        sllx    %g2, 62, %g2
+        and     %o0, %g2, %g2
+        brnz,pt %g2, 5f
+         mov    -1, %g3
+        sllx    %o0, 2, %o0
+        add     %g1, -2, %g1
+5:
+        mov     0, %g2
+        sllx    %g3, 63, %g3
+        and     %o0, %g3, %o0
+        movre   %o0, 1, %g2
+        sub     %g1, %g2, %g1
+        jmp     %o7+8
+         sra    %g1, 0, %o0
+ENDPROC(__fls)
+EXPORT_SYMBOL(__fls)