* [PATCH 1/2] MIPS: add hp-timing support for MIPS R2
@ 2020-10-30 2:14 Huang Pei
2020-10-30 17:02 ` Joseph Myers
0 siblings, 1 reply; 3+ messages in thread
From: Huang Pei @ 2020-10-30 2:14 UTC (permalink / raw)
To: Joseph Myers; +Cc: libc-alpha, Huacai Chen, Chenghua Xu
MIPS R2 only support 32 bit TSC(AKA "rdhwr %0, $2"), but for should be
enough for glibc
Signed-off-by: Huang Pei <huangpei@loongson.cn>
---
sysdeps/mips/hp-timing.h | 43 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 43 insertions(+)
create mode 100644 sysdeps/mips/hp-timing.h
diff --git a/sysdeps/mips/hp-timing.h b/sysdeps/mips/hp-timing.h
new file mode 100644
index 0000000000..de21debdb7
--- /dev/null
+++ b/sysdeps/mips/hp-timing.h
@@ -0,0 +1,43 @@
+/* High precision, low overhead timing functions. MIPS version.
+ Copyright (C) 2002-2020 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef _HP_TIMING_H
+#define _HP_TIMING_H 1
+
+#if __mips_isa_rev => 2
+/* We always assume having the timestamp register. */
+#define HP_TIMING_AVAIL (0)
+#define HP_SMALL_TIMING_AVAIL (1)
+
+/* We indeed have inlined functions. */
+#define HP_TIMING_INLINE (1)
+
+/* We use 32bit values for the times. */
+typedef unsigned int hp_timing_t;
+
+/* Read the cp0 count, this maybe inaccurate. */
+#define HP_TIMING_NOW(Var) \
+ ({ unsigned int _count; \
+ asm volatile ("rdhwr\t%0,$2" : "=r" (_count)); \
+ (Var) = _count; })
+
+#include <hp-timing-common.h>
+
+#endif
+
+#endif /* hp-timing.h */
--
2.17.1
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 1/2] MIPS: add hp-timing support for MIPS R2
2020-10-30 2:14 [PATCH 1/2] MIPS: add hp-timing support for MIPS R2 Huang Pei
@ 2020-10-30 17:02 ` Joseph Myers
2020-10-31 3:32 ` Huang Pei
0 siblings, 1 reply; 3+ messages in thread
From: Joseph Myers @ 2020-10-30 17:02 UTC (permalink / raw)
To: Huang Pei; +Cc: Huacai Chen, Chenghua Xu, libc-alpha
On Fri, 30 Oct 2020, Huang Pei wrote:
> +#if __mips_isa_rev => 2
How was this patch tested? C syntax is >=, not =>.
--
Joseph S. Myers
joseph@codesourcery.com
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 1/2] MIPS: add hp-timing support for MIPS R2
2020-10-30 17:02 ` Joseph Myers
@ 2020-10-31 3:32 ` Huang Pei
0 siblings, 0 replies; 3+ messages in thread
From: Huang Pei @ 2020-10-31 3:32 UTC (permalink / raw)
To: Joseph Myers; +Cc: Huacai Chen, Chenghua Xu, libc-alpha
Sorry, this one is not test, the tested patches are these two
---------------------------------------------------------------------------
From c6982455c5db25aa1d022f9dad67366c58c71aab Mon Sep 17 00:00:00 2001
From: Chenghua Xu <xuchenghua@loongson.cn>
Date: Sat, 10 Oct 2020 10:00:16 +0800
Subject: [PATCH] [MIPS] add support HP_TIMING.
---
sysdeps/mips/hp-timing.h | 40 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)
create mode 100644 sysdeps/mips/hp-timing.h
diff --git a/sysdeps/mips/hp-timing.h b/sysdeps/mips/hp-timing.h
new file mode 100644
index 00000000..505fbe61
--- /dev/null
+++ b/sysdeps/mips/hp-timing.h
@@ -0,0 +1,40 @@
+/* High precision, low overhead timing functions. x86-64 version.
+ Copyright (C) 2002-2018 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef _HP_TIMING_H
+#define _HP_TIMING_H 1
+
+/* We always assume having the timestamp register. */
+#define HP_TIMING_AVAIL (1)
+#define HP_SMALL_TIMING_AVAIL (1)
+
+/* We indeed have inlined functions. */
+#define HP_TIMING_INLINE (1)
+
+/* We use 64bit values for the times. */
+typedef unsigned long long int hp_timing_t;
+
+/* Read the cp0 count, this maybe inaccurate. */
+#define HP_TIMING_NOW(Var) \
+ ({ unsigned long long int _count; \
+ asm volatile ("rdhwr\t%0,$2" : "=r" (_count)); \
+ (Var) = _count; })
+
+#include <hp-timing-common.h>
+
+#endif /* hp-timing.h */
--
2.20.1
---------------------------------------------------------------------------
Description: add high-precision count support
Loongson 3A(3A1000/3B1500) can use "dmfc0" to read 64bit cycle counter from
PMU $25,1, which can be used as TSC
.
glibc (2.28-11) unstable; urgency=medium
.
[ Huang Pei ]
* debian/patches/mips-hp-count-glibc.patch: add high-precision count
for loongson 3a
Author: Huang Pei <huangpei@loongson.cn>
---
The information above should follow the Patch Tagging Guidelines, please
checkout http://dep.debian.net/deps/dep3/ to learn about the format. Here
are templates for supplementary fields that you might want to add:
Origin: <vendor|upstream|other>, <url of original patch>
Bug: <url in upstream bugtracker>
Bug-Debian: https://bugs.debian.org/<bugnumber>
Bug-Ubuntu: https://launchpad.net/bugs/<bugnumber>
Forwarded: <no|not-needed|url proving that it has been forwarded>
Reviewed-By: <name and email of someone who approved the patch>
Last-Update: 2020-10-15
Index: glibc-2.28/sysdeps/mips/hp-timing.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ glibc-2.28/sysdeps/mips/hp-timing.h 2020-10-19 09:01:16.010372407 +0000
@@ -0,0 +1,61 @@
+/* High precision, low overhead timing functions. x86-64 version.
+ Copyright (C) 2002-2018 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef _HP_TIMING_H
+#define _HP_TIMING_H 1
+#include <sgidefs.h>
+
+#if _MIPS_SIM == _ABIO32
+/* We always assume having the timestamp register. */
+#define HP_TIMING_AVAIL (0)
+#define HP_SMALL_TIMING_AVAIL (1)
+
+/* We indeed have inlined functions. */
+#define HP_TIMING_INLINE (1)
+
+/* We use 32bit values for the times. */
+typedef unsigned int hp_timing_t;
+
+/* Read the cp0 count, this maybe inaccurate. */
+#define HP_TIMING_NOW(Var) \
+ ({ unsigned int _count; \
+ asm volatile ("rdhwr\t%0,$2" : "=r" (_count)); \
+ (Var) = _count; })
+
+#else /* _ABIO32 */
+/* We always assume having the timestamp register. */
+#define HP_TIMING_AVAIL (1)
+#define HP_SMALL_TIMING_AVAIL (1)
+
+/* We indeed have inlined functions. */
+#define HP_TIMING_INLINE (1)
+
+/* We use 64bit values for the times. */
+typedef unsigned long long int hp_timing_t;
+
+/* Read the PMU count, this maybe inaccurate. */
+#define HP_TIMING_NOW(Var) \
+ ({ unsigned long long int _count; \
+ asm volatile ("dmfc0\t%0,$25,1" : "=r" (_count)); \
+ (Var) = _count; })
+
+#endif /* !_ABIO32 */
+
+#include <hp-timing-common.h>
+
+#endif /* hp-timing.h */
---------------------------------------------------------------------------
The first one both came from and is tested by xuchenghua@loongson.cn, on
Loongson 3A2000+, the second one came from and is tested by me on Debian
10 mips64el on 3A1000 with customized kernel
We test it with 'LD_DEBUG=statistics'
the first one can run mips o32/n32/n64, but depend on MIPS R2 ISA
and is restricted by 32bit counter;
the second one run n32/n64 with 64bit TSC, but only work on Loongson 3 with
customized kernel or 64bit Stable Counter of Loongson 3A2000+ with
"rdhwr %0, $30"
In order not to affect pre-MIPS R2 CPU, I add the __mips_rev_isa test,
and OOPS
PS:
+. Some CPU of Loongson 3A series can read PMU from userspace, so I use 64bit
event "cycle" to emulate TSC
+. Linux/MIPS kernel set CP0 Hwena for all >= MIPS R2 CPUs, which is
needed by 'rdhwr'
this is the revised one:
From 93421d132a18752800a3d86ece0a81c6a9067704 Mon Sep 17 00:00:00 2001
From: Huang Pei <huangpei@loongson.cn>
Date: Tue, 27 Oct 2020 09:21:09 +0800
Subject: [PATCH 1/2] MIPS: add hp-timing support for MIPS R2
MIPS R2 only support 32 bit TSC(AKA "rdhwr %0, $2"), but for should be
enough for glibc
Signed-off-by: Huang Pei <huangpei@loongson.cn>
---
sysdeps/mips/hp-timing.h | 43 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 43 insertions(+)
create mode 100644 sysdeps/mips/hp-timing.h
diff --git a/sysdeps/mips/hp-timing.h b/sysdeps/mips/hp-timing.h
new file mode 100644
index 0000000000..de21debdb7
--- /dev/null
+++ b/sysdeps/mips/hp-timing.h
@@ -0,0 +1,43 @@
+/* High precision, low overhead timing functions. MIPS version.
+ Copyright (C) 2002-2020 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef _HP_TIMING_H
+#define _HP_TIMING_H 1
+
+#if __mips_isa_rev >= 2
+/* We always assume having the timestamp register. */
+#define HP_TIMING_AVAIL (0)
+#define HP_SMALL_TIMING_AVAIL (1)
+
+/* We indeed have inlined functions. */
+#define HP_TIMING_INLINE (1)
+
+/* We use 32bit values for the times. */
+typedef unsigned int hp_timing_t;
+
+/* Read the cp0 count, this maybe inaccurate. */
+#define HP_TIMING_NOW(Var) \
+ ({ unsigned int _count; \
+ asm volatile ("rdhwr\t%0,$2" : "=r" (_count)); \
+ (Var) = _count; })
+
+#include <hp-timing-common.h>
+
+#endif
+
+#endif /* hp-timing.h */
--
2.17.1
On Fri, Oct 30, 2020 at 05:02:08PM +0000, Joseph Myers wrote:
> On Fri, 30 Oct 2020, Huang Pei wrote:
>
> > +#if __mips_isa_rev => 2
>
> How was this patch tested? C syntax is >=, not =>.
>
> --
> Joseph S. Myers
> joseph@codesourcery.com
^ permalink raw reply [flat|nested] 3+ messages in thread
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