git: 3a909754a10e - stable/13 - Import the arm64 Cortex Strings memset into the kernel
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Date: Wed, 21 Sep 2022 09:46:49 UTC
The branch stable/13 has been updated by andrew:
URL: https://cgit.FreeBSD.org/src/commit/?id=3a909754a10ead4e6d9e85f2f03ff8b8bcb5b29f
commit 3a909754a10ead4e6d9e85f2f03ff8b8bcb5b29f
Author: Andrew Turner <andrew@FreeBSD.org>
AuthorDate: 2022-09-07 11:41:13 +0000
Commit: Andrew Turner <andrew@FreeBSD.org>
CommitDate: 2022-09-21 09:45:53 +0000
Import the arm64 Cortex Strings memset into the kernel
Bring in the last version of the optimized memset from the Cortex
Strings library that didn't use the VFP registers. While here clean up
to use the ENTRY/EDIT macros.
This is imported from:
https://git.linaro.org/toolchain/cortex-strings.git/tree/src/aarch64/memset.S?id=bc654e7a594385071b42db3c9c94bd0fd5fe0da5
Sponsored by: The FreeBSD Foundation
(cherry picked from commit 949bc17cf28bb0a21b4688f1effad01de63d3318)
---
sys/arm64/arm64/memset.S | 235 +++++++++++++++++++++++++++++++++++++++++++++++
sys/conf/files.arm64 | 3 +-
2 files changed, 236 insertions(+), 2 deletions(-)
diff --git a/sys/arm64/arm64/memset.S b/sys/arm64/arm64/memset.S
new file mode 100644
index 000000000000..aaa196d35278
--- /dev/null
+++ b/sys/arm64/arm64/memset.S
@@ -0,0 +1,235 @@
+/* Copyright (c) 2012, Linaro Limited
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+ * Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ * 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.
+ * 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. */
+
+/* Assumptions:
+ *
+ * ARMv8-a, AArch64
+ * Unaligned accesses
+ *
+ */
+
+#include <machine/asm.h>
+
+
+/* By default we assume that the DC instruction can be used to zero
+ data blocks more efficiently. In some circumstances this might be
+ unsafe, for example in an asymmetric multiprocessor environment with
+ different DC clear lengths (neither the upper nor lower lengths are
+ safe to use). The feature can be disabled by defining DONT_USE_DC.
+
+ If code may be run in a virtualized environment, then define
+ MAYBE_VIRT. This will cause the code to cache the system register
+ values rather than re-reading them each call. */
+
+#define dstin x0
+#define val w1
+#define count x2
+#define tmp1 x3
+#define tmp1w w3
+#define tmp2 x4
+#define tmp2w w4
+#define zva_len_x x5
+#define zva_len w5
+#define zva_bits_x x6
+
+#define A_l x7
+#define A_lw w7
+#define dst x8
+#define tmp3w w9
+
+ENTRY(memset)
+
+ mov dst, dstin /* Preserve return value. */
+ ands A_lw, val, #255
+#ifndef DONT_USE_DC
+ b.eq .Lzero_mem
+#endif
+ orr A_lw, A_lw, A_lw, lsl #8
+ orr A_lw, A_lw, A_lw, lsl #16
+ orr A_l, A_l, A_l, lsl #32
+.Ltail_maybe_long:
+ cmp count, #64
+ b.ge .Lnot_short
+.Ltail_maybe_tiny:
+ cmp count, #15
+ b.le .Ltail15tiny
+.Ltail63:
+ ands tmp1, count, #0x30
+ b.eq .Ltail15
+ add dst, dst, tmp1
+ cmp tmp1w, #0x20
+ b.eq 1f
+ b.lt 2f
+ stp A_l, A_l, [dst, #-48]
+1:
+ stp A_l, A_l, [dst, #-32]
+2:
+ stp A_l, A_l, [dst, #-16]
+
+.Ltail15:
+ and count, count, #15
+ add dst, dst, count
+ stp A_l, A_l, [dst, #-16] /* Repeat some/all of last store. */
+ ret
+
+.Ltail15tiny:
+ /* Set up to 15 bytes. Does not assume earlier memory
+ being set. */
+ tbz count, #3, 1f
+ str A_l, [dst], #8
+1:
+ tbz count, #2, 1f
+ str A_lw, [dst], #4
+1:
+ tbz count, #1, 1f
+ strh A_lw, [dst], #2
+1:
+ tbz count, #0, 1f
+ strb A_lw, [dst]
+1:
+ ret
+
+ /* Critical loop. Start at a new cache line boundary. Assuming
+ * 64 bytes per line, this ensures the entire loop is in one line. */
+ .p2align 6
+.Lnot_short:
+ neg tmp2, dst
+ ands tmp2, tmp2, #15
+ b.eq 2f
+ /* Bring DST to 128-bit (16-byte) alignment. We know that there's
+ * more than that to set, so we simply store 16 bytes and advance by
+ * the amount required to reach alignment. */
+ sub count, count, tmp2
+ stp A_l, A_l, [dst]
+ add dst, dst, tmp2
+ /* There may be less than 63 bytes to go now. */
+ cmp count, #63
+ b.le .Ltail63
+2:
+ sub dst, dst, #16 /* Pre-bias. */
+ sub count, count, #64
+1:
+ stp A_l, A_l, [dst, #16]
+ stp A_l, A_l, [dst, #32]
+ stp A_l, A_l, [dst, #48]
+ stp A_l, A_l, [dst, #64]!
+ subs count, count, #64
+ b.ge 1b
+ tst count, #0x3f
+ add dst, dst, #16
+ b.ne .Ltail63
+ ret
+
+#ifndef DONT_USE_DC
+ /* For zeroing memory, check to see if we can use the ZVA feature to
+ * zero entire 'cache' lines. */
+.Lzero_mem:
+ mov A_l, #0
+ cmp count, #63
+ b.le .Ltail_maybe_tiny
+ neg tmp2, dst
+ ands tmp2, tmp2, #15
+ b.eq 1f
+ sub count, count, tmp2
+ stp A_l, A_l, [dst]
+ add dst, dst, tmp2
+ cmp count, #63
+ b.le .Ltail63
+1:
+ /* For zeroing small amounts of memory, it's not worth setting up
+ * the line-clear code. */
+ cmp count, #128
+ b.lt .Lnot_short
+#ifdef MAYBE_VIRT
+ /* For efficiency when virtualized, we cache the ZVA capability. */
+ adrp tmp2, .Lcache_clear
+ ldr zva_len, [tmp2, #:lo12:.Lcache_clear]
+ tbnz zva_len, #31, .Lnot_short
+ cbnz zva_len, .Lzero_by_line
+ mrs tmp1, dczid_el0
+ tbz tmp1, #4, 1f
+ /* ZVA not available. Remember this for next time. */
+ mov zva_len, #~0
+ str zva_len, [tmp2, #:lo12:.Lcache_clear]
+ b .Lnot_short
+1:
+ mov tmp3w, #4
+ and zva_len, tmp1w, #15 /* Safety: other bits reserved. */
+ lsl zva_len, tmp3w, zva_len
+ str zva_len, [tmp2, #:lo12:.Lcache_clear]
+#else
+ mrs tmp1, dczid_el0
+ tbnz tmp1, #4, .Lnot_short
+ mov tmp3w, #4
+ and zva_len, tmp1w, #15 /* Safety: other bits reserved. */
+ lsl zva_len, tmp3w, zva_len
+#endif
+
+.Lzero_by_line:
+ /* Compute how far we need to go to become suitably aligned. We're
+ * already at quad-word alignment. */
+ cmp count, zva_len_x
+ b.lt .Lnot_short /* Not enough to reach alignment. */
+ sub zva_bits_x, zva_len_x, #1
+ neg tmp2, dst
+ ands tmp2, tmp2, zva_bits_x
+ b.eq 1f /* Already aligned. */
+ /* Not aligned, check that there's enough to copy after alignment. */
+ sub tmp1, count, tmp2
+ cmp tmp1, #64
+ ccmp tmp1, zva_len_x, #8, ge /* NZCV=0b1000 */
+ b.lt .Lnot_short
+ /* We know that there's at least 64 bytes to zero and that it's safe
+ * to overrun by 64 bytes. */
+ mov count, tmp1
+2:
+ stp A_l, A_l, [dst]
+ stp A_l, A_l, [dst, #16]
+ stp A_l, A_l, [dst, #32]
+ subs tmp2, tmp2, #64
+ stp A_l, A_l, [dst, #48]
+ add dst, dst, #64
+ b.ge 2b
+ /* We've overrun a bit, so adjust dst downwards. */
+ add dst, dst, tmp2
+1:
+ sub count, count, zva_len_x
+3:
+ dc zva, dst
+ add dst, dst, zva_len_x
+ subs count, count, zva_len_x
+ b.ge 3b
+ ands count, count, zva_bits_x
+ b.ne .Ltail_maybe_long
+ ret
+#ifdef MAYBE_VIRT
+ .bss
+ .p2align 2
+.Lcache_clear:
+ .space 4
+#endif
+#endif /* DONT_USE_DC */
+END(memset)
diff --git a/sys/conf/files.arm64 b/sys/conf/files.arm64
index 963ee0aef8f0..221ec6d0e409 100644
--- a/sys/conf/files.arm64
+++ b/sys/conf/files.arm64
@@ -10,8 +10,6 @@ kern/subr_devmap.c standard
kern/subr_intr.c optional intrng
kern/subr_physmem.c standard
libkern/bcmp.c standard
-libkern/memset.c standard \
- compile-with "${NORMAL_C:N-fsanitize*}"
libkern/strlen.c standard
libkern/arm64/crc32c_armv8.S standard
@@ -60,6 +58,7 @@ arm64/arm64/machdep_boot.c standard
arm64/arm64/mem.c standard
arm64/arm64/memcmp.S standard
arm64/arm64/memcpy.S standard
+arm64/arm64/memset.S standard
arm64/arm64/minidump_machdep.c standard
arm64/arm64/mp_machdep.c optional smp
arm64/arm64/nexus.c standard