lkml.org 
[lkml]   [2017]   [Oct]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v3 2/5] sparc64: Define SPARC default __fls function
Date
__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>
---
arch/sparc/include/asm/bitops_64.h | 2 +-
arch/sparc/lib/Makefile | 1 +
arch/sparc/lib/fls64.S | 61 ++++++++++++++++++++++++++++++++++++
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 30aea56..d7a46e2 100644
--- a/arch/sparc/include/asm/bitops_64.h
+++ b/arch/sparc/include/asm/bitops_64.h
@@ -23,10 +23,10 @@
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 3b9f5e0..5380c59 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 0000000..c83e22a
--- /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)
--
1.7.1
\
 
 \ /
  Last update: 2017-10-06 18:56    [W:0.061 / U:0.284 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site