summaryrefslogtreecommitdiffstats
path: root/kernel/arch/alpha/lib/ev67-strncat.S
diff options
context:
space:
mode:
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/alpha/lib/ev67-strncat.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/alpha/lib/ev67-strncat.S')
-rw-r--r--kernel/arch/alpha/lib/ev67-strncat.S94
1 files changed, 94 insertions, 0 deletions
diff --git a/kernel/arch/alpha/lib/ev67-strncat.S b/kernel/arch/alpha/lib/ev67-strncat.S
new file mode 100644
index 000000000..4ae716cd2
--- /dev/null
+++ b/kernel/arch/alpha/lib/ev67-strncat.S
@@ -0,0 +1,94 @@
+/*
+ * arch/alpha/lib/ev67-strncat.S
+ * 21264 version contributed by Rick Gorton <rick.gorton@api-networks.com>
+ *
+ * Append no more than COUNT characters from the null-terminated string SRC
+ * to the null-terminated string DST. Always null-terminate the new DST.
+ *
+ * This differs slightly from the semantics in libc in that we never write
+ * past count, whereas libc may write to count+1. This follows the generic
+ * implementation in lib/string.c and is, IMHO, more sensible.
+ *
+ * Much of the information about 21264 scheduling/coding comes from:
+ * Compiler Writer's Guide for the Alpha 21264
+ * abbreviated as 'CWG' in other comments here
+ * ftp.digital.com/pub/Digital/info/semiconductor/literature/dsc-library.html
+ * Scheduling notation:
+ * E - either cluster
+ * U - upper subcluster; U0 - subcluster U0; U1 - subcluster U1
+ * L - lower subcluster; L0 - subcluster L0; L1 - subcluster L1
+ * Try not to change the actual algorithm if possible for consistency.
+ */
+
+
+ .text
+
+ .align 4
+ .globl strncat
+ .ent strncat
+strncat:
+ .frame $30, 0, $26
+ .prologue 0
+
+ mov $16, $0 # set up return value
+ beq $18, $zerocount # U :
+ /* Find the end of the string. */
+ ldq_u $1, 0($16) # L : load first quadword ($16 may be misaligned)
+ lda $2, -1($31) # E :
+
+ insqh $2, $0, $2 # U :
+ andnot $16, 7, $16 # E :
+ nop # E :
+ or $2, $1, $1 # E :
+
+ nop # E :
+ nop # E :
+ cmpbge $31, $1, $2 # E : bits set iff byte == 0
+ bne $2, $found # U :
+
+$loop: ldq $1, 8($16) # L :
+ addq $16, 8, $16 # E :
+ cmpbge $31, $1, $2 # E :
+ beq $2, $loop # U :
+
+$found: cttz $2, $3 # U0 :
+ addq $16, $3, $16 # E :
+ nop # E :
+ bsr $23, __stxncpy # L0 :/* Now do the append. */
+
+ /* Worry about the null termination. */
+
+ zapnot $1, $27, $2 # U : was last byte a null?
+ cmplt $27, $24, $5 # E : did we fill the buffer completely?
+ bne $2, 0f # U :
+ ret # L0 :
+
+0: or $5, $18, $2 # E :
+ nop
+ bne $2, 2f # U :
+ and $24, 0x80, $3 # E : no zero next byte
+
+ nop # E :
+ bne $3, 1f # U :
+ /* Here there are bytes left in the current word. Clear one. */
+ addq $24, $24, $24 # E : end-of-count bit <<= 1
+ nop # E :
+
+2: zap $1, $24, $1 # U :
+ nop # E :
+ stq_u $1, 0($16) # L :
+ ret # L0 :
+
+1: /* Here we must clear the first byte of the next DST word */
+ stb $31, 8($16) # L :
+ nop # E :
+ nop # E :
+ ret # L0 :
+
+$zerocount:
+ nop # E :
+ nop # E :
+ nop # E :
+ ret # L0 :
+
+ .end strncat