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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/microblaze/lib/divsi3.S
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/microblaze/lib/divsi3.S')
-rw-r--r--kernel/arch/microblaze/lib/divsi3.S73
1 files changed, 73 insertions, 0 deletions
diff --git a/kernel/arch/microblaze/lib/divsi3.S b/kernel/arch/microblaze/lib/divsi3.S
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+++ b/kernel/arch/microblaze/lib/divsi3.S
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+#include <linux/linkage.h>
+
+/*
+* Divide operation for 32 bit integers.
+* Input : Dividend in Reg r5
+* Divisor in Reg r6
+* Output: Result in Reg r3
+*/
+ .text
+ .globl __divsi3
+ .type __divsi3, @function
+ .ent __divsi3
+__divsi3:
+ .frame r1, 0, r15
+
+ addik r1, r1, -16
+ swi r28, r1, 0
+ swi r29, r1, 4
+ swi r30, r1, 8
+ swi r31, r1, 12
+
+ beqi r6, div_by_zero /* div_by_zero - division error */
+ beqi r5, result_is_zero /* result is zero */
+ bgeid r5, r5_pos
+ xor r28, r5, r6 /* get the sign of the result */
+ rsubi r5, r5, 0 /* make r5 positive */
+r5_pos:
+ bgei r6, r6_pos
+ rsubi r6, r6, 0 /* make r6 positive */
+r6_pos:
+ addik r30, r0, 0 /* clear mod */
+ addik r3, r0, 0 /* clear div */
+ addik r29, r0, 32 /* initialize the loop count */
+
+ /* first part try to find the first '1' in the r5 */
+div0:
+ blti r5, div2 /* this traps r5 == 0x80000000 */
+div1:
+ add r5, r5, r5 /* left shift logical r5 */
+ bgtid r5, div1
+ addik r29, r29, -1
+div2:
+ /* left shift logical r5 get the '1' into the carry */
+ add r5, r5, r5
+ addc r30, r30, r30 /* move that bit into the mod register */
+ rsub r31, r6, r30 /* try to subtract (r30 a r6) */
+ blti r31, mod_too_small
+ /* move the r31 to mod since the result was positive */
+ or r30, r0, r31
+ addik r3, r3, 1
+mod_too_small:
+ addik r29, r29, -1
+ beqi r29, loop_end
+ add r3, r3, r3 /* shift in the '1' into div */
+ bri div2 /* div2 */
+loop_end:
+ bgei r28, return_here
+ brid return_here
+ rsubi r3, r3, 0 /* negate the result */
+div_by_zero:
+result_is_zero:
+ or r3, r0, r0 /* set result to 0 */
+return_here:
+/* restore values of csrs and that of r3 and the divisor and the dividend */
+ lwi r28, r1, 0
+ lwi r29, r1, 4
+ lwi r30, r1, 8
+ lwi r31, r1, 12
+ rtsd r15, 8
+ addik r1, r1, 16
+
+.size __divsi3, . - __divsi3
+.end __divsi3