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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>
hifive-unleashed-5.1
Vijay Kumar 2017-10-11 12:50:02 -06:00 committed by David S. Miller
parent 9a08862a5d
commit 41413a6035
3 changed files with 70 additions and 1 deletions
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3
arch/sparc/include/asm/bitops_64.h
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@ -22,9 +22,10 @@ void set_bit(unsigned long nr, volatile unsigned long *addr);
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);
#include <asm-generic/bitops/non-atomic.h>
#include <asm-generic/bitops/fls.h>
#include <asm-generic/bitops/__fls.h>
#include <asm-generic/bitops/fls64.h>

1
arch/sparc/lib/Makefile
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@ -16,6 +16,7 @@ lib-$(CONFIG_SPARC64) += atomic_64.o
lib-$(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) += copy_page.o clear_page.o bzero.o
lib-$(CONFIG_SPARC64) += csum_copy.o csum_copy_from_user.o csum_copy_to_user.o

67
arch/sparc/lib/fls.S 100644
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@ -0,0 +1,67 @@
/* fls.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)
brz,pn %o0, 6f
mov 0, %o1
sethi %hi(0xffff0000), %g3
mov %o0, %g2
andcc %o0, %g3, %g0
be,pt %icc, 8f
mov 32, %o1
sethi %hi(0xff000000), %g3
andcc %g2, %g3, %g0
bne,pt %icc, 3f
sethi %hi(0xf0000000), %g3
sll %o0, 8, %o0
1:
add %o1, -8, %o1
sra %o0, 0, %o0
mov %o0, %g2
2:
sethi %hi(0xf0000000), %g3
3:
andcc %g2, %g3, %g0
bne,pt %icc, 4f
sethi %hi(0xc0000000), %g3
sll %o0, 4, %o0
add %o1, -4, %o1
sra %o0, 0, %o0
mov %o0, %g2
4:
andcc %g2, %g3, %g0
be,a,pt %icc, 7f
sll %o0, 2, %o0
5:
xnor %g0, %o0, %o0
srl %o0, 31, %o0
sub %o1, %o0, %o1
6:
jmp %o7 + 8
sra %o1, 0, %o0
7:
add %o1, -2, %o1
ba,pt %xcc, 5b
sra %o0, 0, %o0
8:
sll %o0, 16, %o0
sethi %hi(0xff000000), %g3
sra %o0, 0, %o0
mov %o0, %g2
andcc %g2, %g3, %g0
bne,pt %icc, 2b
mov 16, %o1
ba,pt %xcc, 1b
sll %o0, 8, %o0
ENDPROC(fls)
EXPORT_SYMBOL(fls)