1 files changed, 202 insertions, 0 deletions

diff --git a/arch/powerpc/lib/string_64.S b/arch/powerpc/lib/string_64.S
new file mode 100644
index 000000000000..3b1e48049faf
--- /dev/null
+++ b/arch/powerpc/lib/string_64.S
@@ -0,0 +1,202 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright (C) IBM Corporation, 2012
+ *
+ * Author: Anton Blanchard <anton@au.ibm.com>
+ */
+
+#include <asm/ppc_asm.h>
+#include <asm/asm-offsets.h>
+
+        .section        ".toc","aw"
+PPC64_CACHES:
+        .tc             ppc64_caches[TC],ppc64_caches
+        .section        ".text"
+
+/**
+ * __clear_user: - Zero a block of memory in user space, with less checking.
+ * @to:   Destination address, in user space.
+ * @n:    Number of bytes to zero.
+ *
+ * Zero a block of memory in user space.  Caller must check
+ * the specified block with access_ok() before calling this function.
+ *
+ * Returns number of bytes that could not be cleared.
+ * On success, this will be zero.
+ */
+
+        .macro err1
+100:
+        .section __ex_table,"a"
+        .align 3
+        .llong 100b,.Ldo_err1
+        .previous
+        .endm
+
+        .macro err2
+200:
+        .section __ex_table,"a"
+        .align 3
+        .llong 200b,.Ldo_err2
+        .previous
+        .endm
+
+        .macro err3
+300:
+        .section __ex_table,"a"
+        .align 3
+        .llong 300b,.Ldo_err3
+        .previous
+        .endm
+
+.Ldo_err1:
+        mr      r3,r8
+
+.Ldo_err2:
+        mtctr   r4
+1:
+err3;   stb     r0,0(r3)
+        addi    r3,r3,1
+        addi    r4,r4,-1
+        bdnz    1b
+
+.Ldo_err3:
+        mr      r3,r4
+        blr
+
+_GLOBAL(__clear_user)
+        cmpdi   r4,32
+        neg     r6,r3
+        li      r0,0
+        blt     .Lshort_clear
+        mr      r8,r3
+        mtocrf  0x01,r6
+        clrldi  r6,r6,(64-3)
+
+        /* Get the destination 8 byte aligned */
+        bf      cr7*4+3,1f
+err1;   stb     r0,0(r3)
+        addi    r3,r3,1
+
+1:      bf      cr7*4+2,2f
+err1;   sth     r0,0(r3)
+        addi    r3,r3,2
+
+2:      bf      cr7*4+1,3f
+err1;   stw     r0,0(r3)
+        addi    r3,r3,4
+
+3:      sub     r4,r4,r6
+
+        cmpdi   r4,32
+        cmpdi   cr1,r4,512
+        blt     .Lshort_clear
+        bgt     cr1,.Llong_clear
+
+.Lmedium_clear:
+        srdi    r6,r4,5
+        mtctr   r6
+
+        /* Do 32 byte chunks */
+4:
+err2;   std     r0,0(r3)
+err2;   std     r0,8(r3)
+err2;   std     r0,16(r3)
+err2;   std     r0,24(r3)
+        addi    r3,r3,32
+        addi    r4,r4,-32
+        bdnz    4b
+
+.Lshort_clear:
+        /* up to 31 bytes to go */
+        cmpdi   r4,16
+        blt     6f
+err2;   std     r0,0(r3)
+err2;   std     r0,8(r3)
+        addi    r3,r3,16
+        addi    r4,r4,-16
+
+        /* Up to 15 bytes to go */
+6:      mr      r8,r3
+        clrldi  r4,r4,(64-4)
+        mtocrf  0x01,r4
+        bf      cr7*4+0,7f
+err1;   std     r0,0(r3)
+        addi    r3,r3,8
+
+7:      bf      cr7*4+1,8f
+err1;   stw     r0,0(r3)
+        addi    r3,r3,4
+
+8:      bf      cr7*4+2,9f
+err1;   sth     r0,0(r3)
+        addi    r3,r3,2
+
+9:      bf      cr7*4+3,10f
+err1;   stb     r0,0(r3)
+
+10:     li      r3,0
+        blr
+
+.Llong_clear:
+        ld      r5,PPC64_CACHES@toc(r2)
+
+        bf      cr7*4+0,11f
+err2;   std     r0,0(r3)
+        addi    r3,r3,8
+        addi    r4,r4,-8
+
+        /* Destination is 16 byte aligned, need to get it cacheline aligned */
+11:     lwz     r7,DCACHEL1LOGLINESIZE(r5)
+        lwz     r9,DCACHEL1LINESIZE(r5)
+
+        /*
+         * With worst case alignment the long clear loop takes a minimum
+         * of 1 byte less than 2 cachelines.
+         */
+        sldi    r10,r9,2
+        cmpd    r4,r10
+        blt     .Lmedium_clear
+
+        neg     r6,r3
+        addi    r10,r9,-1
+        and.    r5,r6,r10
+        beq     13f
+
+        srdi    r6,r5,4
+        mtctr   r6
+        mr      r8,r3
+12:
+err1;   std     r0,0(r3)
+err1;   std     r0,8(r3)
+        addi    r3,r3,16
+        bdnz    12b
+
+        sub     r4,r4,r5
+
+13:     srd     r6,r4,r7
+        mtctr   r6
+        mr      r8,r3
+14:
+err1;   dcbz    r0,r3
+        add     r3,r3,r9
+        bdnz    14b
+
+        and     r4,r4,r10
+
+        cmpdi   r4,32
+        blt     .Lshort_clear
+        b       .Lmedium_clear