@@ -15,7 +15,6 @@
*/
#include <linux/linkage.h>
-#include <asm/assembler.h>
/*
* Copy from user space to a kernel buffer (alignment handled by the hardware)
@@ -28,39 +27,68 @@
* x0 - bytes not copied
*/
ENTRY(__copy_from_user)
- add x4, x1, x2 // upper user buffer boundary
- subs x2, x2, #8
- b.mi 2f
-1:
-USER(9f, ldr x3, [x1], #8 )
- subs x2, x2, #8
- str x3, [x0], #8
- b.pl 1b
-2: adds x2, x2, #4
- b.mi 3f
-USER(9f, ldr w3, [x1], #4 )
- sub x2, x2, #4
- str w3, [x0], #4
-3: adds x2, x2, #2
- b.mi 4f
-USER(9f, ldrh w3, [x1], #2 )
- sub x2, x2, #2
- strh w3, [x0], #2
-4: adds x2, x2, #1
- b.mi 5f
-USER(9f, ldrb w3, [x1] )
- strb w3, [x0]
-5: mov x0, #0
- ret
+#include "copy_template.S"
ENDPROC(__copy_from_user)
.section .fixup,"ax"
- .align 2
-9: sub x2, x4, x1
- mov x3, x2
-10: strb wzr, [x0], #1 // zero remaining buffer space
- subs x3, x3, #1
- b.ne 10b
- mov x0, x2 // bytes not copied
+ .align 2
+9:
+ /*
+ * count is accurate
+ * dst is accurate
+ */
+ mov x0, count
+ sub dst, dst, tmp1
+ b .Lfinalize
+
+10:
+ /*
+ * count is in the last 15 bytes
+ * dst is somewhere in there
+ */
+ mov x0, count
+ sub dst, limit, count
+ b .Lfinalize
+11:
+ /*
+ * count over counted by tmp2
+ * dst could be anywhere in there
+ */
+ add x0, count, tmp2
+ sub dst, limit, x0
+ b .Lfinalize
+12:
+ /*
+ * (count + 64) bytes remain
+ * dst is accurate
+ */
+ adds x0, count, #64
+ b .Lfinalize
+13:
+ /*
+ * (count + 128) bytes remain
+ * dst is pre-biased to (dst + 16)
+ */
+ adds x0, count, #128
+ add dst, dst, #16
+ b .Lfinalize
+14:
+ /*
+ * (count + 64) bytes remain
+ * dst is pre-biased to (dst + 16)
+ */
+ adds x0, count, #64
+ add dst, dst, #16
+
+.Lfinalize:
+ /*
+ * Zeroize remaining destination-buffer
+ */
+ mov count, x0
+20:
+ /* Zero remaining buffer space */
+ strb wzr, [dst], #1
+ subs count, count, #1
+ b.ne 20b
ret
.previous
new file mode 100644
@@ -0,0 +1,213 @@
+/*
+ * Copyright (c) 2013, Applied Micro Circuits Corporation
+ * Copyright (c) 2012-2013, Linaro Limited
+ *
+ * Author: Feng Kan <fkan@apm.com>
+ * Author: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
+ *
+ * The code is adopted from the memcpy routine by Linaro Limited.
+ *
+ * This file is free software: you may copy, redistribute 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 file 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, see <http://www.gnu.org/licenses/>.
+ *
+ * This file incorporates work covered by the following copyright and
+ * permission notice:
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 1 Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2 Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3 Neither the name of the Linaro nor the
+ * names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <asm/assembler.h>
+#include <asm/cache.h>
+
+dstin .req x0
+src .req x1
+count .req x2
+tmp1 .req x3
+tmp1w .req w3
+tmp2 .req x4
+tmp2w .req w4
+limit .req x5
+dst .req x6
+
+A_l .req x7
+A_h .req x8
+B_l .req x9
+B_h .req x10
+C_l .req x11
+C_h .req x12
+D_l .req x13
+D_h .req x14
+
+ mov dst, dstin
+ add limit, dst, count
+ cmp count, #16
+ b.lo .Ltail15
+
+ /*
+ * We don't much care about the alignment of DST, but we want SRC
+ * to be 128-bit (16 byte) aligned so that we don't cross cache line
+ * boundaries on both loads and stores.
+ */
+ ands tmp2, src, #15
+ b.eq .LSrcAligned
+ sub count, count, tmp2
+
+ tbz tmp2, #0, 1f
+ USER(11f, ldrb tmp1w, [src], #1)
+ USER(11f, strb tmp1w, [dst], #1)
+1:
+ tbz tmp2, #1, 2f
+ USER(11f, ldrh tmp1w, [src], #2)
+ USER(11f, strh tmp1w, [dst], #2)
+2:
+ tbz tmp2, #2, 3f
+ USER(11f, ldr tmp1w, [src], #4)
+ USER(11f, str tmp1w, [dst], #4)
+3:
+ tbz tmp2, #3, .LSrcAligned
+ USER(11f, ldr tmp1, [src], #8)
+ USER(11f, str tmp1, [dst], #8)
+
+.LSrcAligned:
+ /* There may be less than 63 bytes to go now. */
+ cmp count, #64
+ b.ge .Lcpy_over64
+
+ /*
+ * Deal with small copies quickly by dropping straight into the
+ * exit block.
+ */
+.Ltail63:
+ /*
+ * Copy up to 48 bytes of data. At this point we only need the
+ * bottom 6 bits of count to be accurate.
+ */
+ ands tmp1, count, #0x30
+ b.eq .Ltail15
+ add dst, dst, tmp1
+ add src, src, tmp1
+ cmp tmp1w, #0x20
+ b.eq 1f
+ b.lt 2f
+ USER(9f, ldp A_l, A_h, [src, #-48])
+ USER(9f, stp A_l, A_h, [dst, #-48])
+1:
+ USER(9f, ldp A_l, A_h, [src, #-32])
+ USER(9f, stp A_l, A_h, [dst, #-32])
+2:
+ USER(9f, ldp A_l, A_h, [src, #-16])
+ USER(9f, stp A_l, A_h, [dst, #-16])
+
+.Ltail15:
+ ands count, count, #15
+ beq .Lsuccess /* Quick exit if we are done*/
+ /*
+ * Copy up to 15 bytes of data. Does not assume additional data
+ * being copied.
+ */
+ tbz count, #3, 1f
+ USER(10f, ldr tmp1, [src], #8)
+ USER(10f, str tmp1, [dst], #8)
+1:
+ tbz count, #2, 1f
+ USER(10f, ldr tmp1w, [src], #4)
+ USER(10f, str tmp1w, [dst], #4)
+1:
+ tbz count, #1, 1f
+ USER(10f, ldrh tmp1w, [src], #2)
+ USER(10f, strh tmp1w, [dst], #2)
+1:
+ tbz count, #0, 1f
+ USER(10f, ldrb tmp1w, [src], #1)
+ USER(10f, strb tmp1w, [dst], #1)
+1:
+ b .Lsuccess
+
+.Lcpy_over64:
+ subs count, count, #128
+ b.ge .Lcpy_body_large
+ /*
+ * Less than 128 bytes to copy, so handle 64 here and then jump
+ * to the tail.
+ */
+ adds count, count, #64
+ USER(12f, ldp A_l, A_h, [src])
+ USER(12f, ldp B_l, B_h, [src, #16])
+ USER(12f, ldp C_l, C_h, [src, #32])
+ USER(12f, ldp D_l, D_h, [src, #48])
+ USER(12f, stp A_l, A_h, [dst])
+ USER(12f, stp B_l, B_h, [dst, #16])
+ USER(12f, stp C_l, C_h, [dst, #32])
+ USER(12f, stp D_l, D_h, [dst, #48])
+ add src, src, #64
+ add dst, dst, #64
+ tst count, #0x3f
+ b.ne .Ltail63
+ b .Lsuccess
+
+ /*
+ * Critical loop. Start at a new cache line boundary. Assuming
+ * 64 bytes per line this ensures the entire loop is in one line.
+ */
+ .p2align L1_CACHE_SHIFT
+.Lcpy_body_large:
+ /* There are at least 128 bytes to copy. */
+ sub dst, dst, #16 /* Pre-bias. */
+ USER(13f, ldp A_l, A_h, [src, #0])
+ USER(13f, ldp B_l, B_h, [src, #16])
+ USER(13f, ldp C_l, C_h, [src, #32])
+ USER(13f, ldp D_l, D_h, [src, #48]!) /* src += 64 - Pre-bias. */
+1:
+ USER(13f, stp A_l, A_h, [dst, #16])
+ USER(13f, ldp A_l, A_h, [src, #16])
+ USER(13f, stp B_l, B_h, [dst, #32])
+ USER(13f, ldp B_l, B_h, [src, #32])
+ USER(13f, stp C_l, C_h, [dst, #48])
+ USER(13f, ldp C_l, C_h, [src, #48])
+ USER(14f, stp D_l, D_h, [dst, #64]!)
+ USER(14f, ldp D_l, D_h, [src, #64]!)
+ subs count, count, #64
+ b.ge 1b
+ USER(13f, stp A_l, A_h, [dst, #16])
+ USER(13f, stp B_l, B_h, [dst, #32])
+ USER(13f, stp C_l, C_h, [dst, #48])
+ USER(13f, stp D_l, D_h, [dst, #64])
+ add src, src, #16
+ add dst, dst, #80 /* 64 bytes + 16 prebias */
+ adds count, count, #64
+ tst count, #0x3f
+ b.ne .Ltail63
+.Lsuccess:
+ /* Nothing left to copy */
+ mov x0, #0
+ ret
@@ -15,7 +15,6 @@
*/
#include <linux/linkage.h>
-#include <asm/assembler.h>
/*
* Copy to user space from a kernel buffer (alignment handled by the hardware)
@@ -28,34 +27,37 @@
* x0 - bytes not copied
*/
ENTRY(__copy_to_user)
- add x4, x0, x2 // upper user buffer boundary
- subs x2, x2, #8
- b.mi 2f
-1:
- ldr x3, [x1], #8
- subs x2, x2, #8
-USER(9f, str x3, [x0], #8 )
- b.pl 1b
-2: adds x2, x2, #4
- b.mi 3f
- ldr w3, [x1], #4
- sub x2, x2, #4
-USER(9f, str w3, [x0], #4 )
-3: adds x2, x2, #2
- b.mi 4f
- ldrh w3, [x1], #2
- sub x2, x2, #2
-USER(9f, strh w3, [x0], #2 )
-4: adds x2, x2, #1
- b.mi 5f
- ldrb w3, [x1]
-USER(9f, strb w3, [x0] )
-5: mov x0, #0
- ret
+#include "copy_template.S"
ENDPROC(__copy_to_user)
.section .fixup,"ax"
- .align 2
-9: sub x0, x4, x0 // bytes not copied
+ .align 2
+9:
+10:
+ /*
+ * count is accurate
+ */
+ mov x0, count
+ b .Lfinalize
+11:
+ /*
+ * count is over accounted by tmp2
+ */
+ add x0, count, tmp2
+ b .Lfinalize
+12:
+14:
+ /*
+ * (count + 64) bytes remain
+ * dst is accurate
+ */
+ adds x0, count, #64
+ b .Lfinalize
+13:
+ /*
+ * (count + 128) bytes remain
+ */
+ add x0, count, #128
+.Lfinalize:
ret
.previous
Using the glibc cortex string work work authored by Linaro as base to create new copy to/from user kernel routine. Iperf performance increase: -l (size) 1 core result Optimized 64B 44-51Mb/s 1500B 4.9Gb/s 30000B 16.2Gb/s Original 64B 34-50.7Mb/s 1500B 4.7Gb/s 30000B 14.5Gb/s Signed-off-by: Feng Kan <fkan@apm.com> --- arch/arm64/lib/copy_from_user.S | 92 +++++++++++------ arch/arm64/lib/copy_template.S | 213 ++++++++++++++++++++++++++++++++++++++++ arch/arm64/lib/copy_to_user.S | 56 ++++++----- 3 files changed, 302 insertions(+), 59 deletions(-) create mode 100644 arch/arm64/lib/copy_template.S