git: 5a6a4fb284b1 - main - linux(4): Implement vdso getcpu for x86.
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Date: Sun, 08 May 2022 14:21:46 UTC
The branch main has been updated by dchagin:
URL: https://cgit.FreeBSD.org/src/commit/?id=5a6a4fb284b1a9c4b4105fd6ab8143356f3ef3f7
commit 5a6a4fb284b1a9c4b4105fd6ab8143356f3ef3f7
Author: Dmitry Chagin <dchagin@FreeBSD.org>
AuthorDate: 2022-05-08 14:20:52 +0000
Commit: Dmitry Chagin <dchagin@FreeBSD.org>
CommitDate: 2022-05-08 14:20:52 +0000
linux(4): Implement vdso getcpu for x86.
This is modeled after f2395455 (by kib@).
MFC after: 2 weeks
---
sys/amd64/linux/linux_sysvec.c | 7 +++
sys/amd64/linux/linux_vdso.lds.s | 1 +
sys/amd64/linux/linux_vdso_gtod.c | 2 +
sys/amd64/linux32/linux32_sysvec.c | 7 +++
sys/amd64/linux32/linux32_vdso.lds.s | 2 +
sys/amd64/linux32/linux32_vdso_gtod.c | 17 ++++++
sys/compat/linux/linux_vdso_gtod.inc | 13 ++++-
sys/i386/linux/linux_sysvec.c | 7 +++
sys/i386/linux/linux_vdso.lds.s | 2 +
sys/i386/linux/linux_vdso_gtod.c | 17 ++++++
sys/modules/linux/Makefile | 2 +-
sys/modules/linux64/Makefile | 2 +-
sys/x86/linux/linux_vdso_getcpu_x86.inc | 68 ++++++++++++++++++++++
...sc_selector_x86.c => linux_vdso_selector_x86.c} | 26 ++++++++-
sys/x86/linux/linux_x86.h | 5 ++
15 files changed, 172 insertions(+), 6 deletions(-)
diff --git a/sys/amd64/linux/linux_sysvec.c b/sys/amd64/linux/linux_sysvec.c
index aad594ec3130..1ea274da8935 100644
--- a/sys/amd64/linux/linux_sysvec.c
+++ b/sys/amd64/linux/linux_sysvec.c
@@ -172,6 +172,7 @@ LINUX_VDSO_SYM_INTPTR(linux_rt_sigcode);
LINUX_VDSO_SYM_CHAR(linux_platform);
LINUX_VDSO_SYM_INTPTR(kern_timekeep_base);
LINUX_VDSO_SYM_INTPTR(kern_tsc_selector);
+LINUX_VDSO_SYM_INTPTR(kern_cpu_selector);
/*
* If FreeBSD & Linux have a difference of opinion about what a trap
@@ -837,6 +838,12 @@ linux_exec_sysvec_init(void *param)
*ktsc_selector = linux_vdso_tsc_selector_idx();
if (bootverbose)
printf("Linux x86-64 vDSO tsc_selector: %lu\n", *ktsc_selector);
+
+ tkoff = kern_cpu_selector - linux_vdso_base;
+ ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff);
+ *ktsc_selector = linux_vdso_cpu_selector_idx();
+ if (bootverbose)
+ printf("Linux x86-64 vDSO cpu_selector: %lu\n", *ktsc_selector);
}
SYSINIT(elf_linux_exec_sysvec_init, SI_SUB_EXEC + 1, SI_ORDER_ANY,
linux_exec_sysvec_init, &elf_linux_sysvec);
diff --git a/sys/amd64/linux/linux_vdso.lds.s b/sys/amd64/linux/linux_vdso.lds.s
index ccf7c80565bb..24d8cab162f8 100644
--- a/sys/amd64/linux/linux_vdso.lds.s
+++ b/sys/amd64/linux/linux_vdso.lds.s
@@ -68,6 +68,7 @@ VERSION
linux_platform;
kern_timekeep_base;
kern_tsc_selector;
+ kern_cpu_selector;
local: *;
};
}
diff --git a/sys/amd64/linux/linux_vdso_gtod.c b/sys/amd64/linux/linux_vdso_gtod.c
index 65e45ce29505..3d18b551e6fb 100644
--- a/sys/amd64/linux/linux_vdso_gtod.c
+++ b/sys/amd64/linux/linux_vdso_gtod.c
@@ -49,8 +49,10 @@ __FBSDID("$FreeBSD$");
/* The kernel fixup this at vDSO install */
uintptr_t *kern_timekeep_base = NULL;
uint32_t kern_tsc_selector = 0;
+uint32_t kern_cpu_selector = 0;
#include <x86/linux/linux_vdso_gettc_x86.inc>
+#include <x86/linux/linux_vdso_getcpu_x86.inc>
/* for debug purpose */
static int
diff --git a/sys/amd64/linux32/linux32_sysvec.c b/sys/amd64/linux32/linux32_sysvec.c
index 782ab2246061..b57d6f93d94b 100644
--- a/sys/amd64/linux32/linux32_sysvec.c
+++ b/sys/amd64/linux32/linux32_sysvec.c
@@ -185,6 +185,7 @@ LINUX_VDSO_SYM_INTPTR(__kernel_sigreturn);
LINUX_VDSO_SYM_INTPTR(__kernel_rt_sigreturn);
LINUX_VDSO_SYM_INTPTR(kern_timekeep_base);
LINUX_VDSO_SYM_INTPTR(kern_tsc_selector);
+LINUX_VDSO_SYM_INTPTR(kern_cpu_selector);
LINUX_VDSO_SYM_CHAR(linux_platform);
/*
@@ -1000,6 +1001,12 @@ linux_exec_sysvec_init(void *param)
*ktsc_selector = linux_vdso_tsc_selector_idx();
if (bootverbose)
printf("Linux i386 vDSO tsc_selector: %u\n", *ktsc_selector);
+
+ tkoff = kern_cpu_selector - linux_vdso_base;
+ ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff);
+ *ktsc_selector = linux_vdso_cpu_selector_idx();
+ if (bootverbose)
+ printf("Linux i386 vDSO cpu_selector: %u\n", *ktsc_selector);
}
SYSINIT(elf_linux_exec_sysvec_init, SI_SUB_EXEC + 1, SI_ORDER_ANY,
linux_exec_sysvec_init, &elf_linux_sysvec);
diff --git a/sys/amd64/linux32/linux32_vdso.lds.s b/sys/amd64/linux32/linux32_vdso.lds.s
index 0a392e6380b6..cd5b4a20dee0 100644
--- a/sys/amd64/linux32/linux32_vdso.lds.s
+++ b/sys/amd64/linux32/linux32_vdso.lds.s
@@ -58,6 +58,7 @@ VERSION
__vdso_clock_gettime;
__vdso_gettimeofday;
__vdso_time;
+ __vdso_getcpu;
__vdso_clock_getres;
__vdso_clock_gettime64;
};
@@ -75,6 +76,7 @@ VERSION
linux_platform;
kern_timekeep_base;
kern_tsc_selector;
+ kern_cpu_selector;
local: *;
};
}
diff --git a/sys/amd64/linux32/linux32_vdso_gtod.c b/sys/amd64/linux32/linux32_vdso_gtod.c
index bbe15e462c09..4f9892af3fa5 100644
--- a/sys/amd64/linux32/linux32_vdso_gtod.c
+++ b/sys/amd64/linux32/linux32_vdso_gtod.c
@@ -50,8 +50,10 @@ __FBSDID("$FreeBSD$");
/* The kernel fixup this at vDSO install */
uintptr_t *kern_timekeep_base = NULL;
uint32_t kern_tsc_selector = 0;
+uint32_t kern_cpu_selector = 0;
#include <x86/linux/linux_vdso_gettc_x86.inc>
+#include <x86/linux/linux_vdso_getcpu_x86.inc>
static int
write(int fd, const void *buf, size_t size)
@@ -128,6 +130,21 @@ __vdso_clock_getres_fallback(clockid_t clock_id, struct l_timespec *ts)
return (res);
}
+static int
+__vdso_getcpu_fallback(uint32_t *cpu, uint32_t *node, void *cache)
+{
+ int res;
+
+ __asm__ __volatile__
+ (
+ "int $0x80"
+ : "=a"(res)
+ : "a"(LINUX32_SYS_linux_getcpu), "D"(cpu), "S"(node), "d"(cache)
+ : "cc", "memory"
+ );
+ return (res);
+}
+
static int
__vdso_time_fallback(long *tm)
{
diff --git a/sys/compat/linux/linux_vdso_gtod.inc b/sys/compat/linux/linux_vdso_gtod.inc
index 52fab2bbc5d7..7320ce998d80 100644
--- a/sys/compat/linux/linux_vdso_gtod.inc
+++ b/sys/compat/linux/linux_vdso_gtod.inc
@@ -352,12 +352,19 @@ int clock_gettime64(clockid_t clock_id, struct l_timespec64 *lts)
__attribute__((weak, alias("__vdso_clock_gettime64")));
#endif
-#if defined(__amd64__) && !defined(COMPAT_LINUX32)
+#if defined(__i386__) || defined(__amd64__)
int
__vdso_getcpu(uint32_t *cpu, uint32_t *node, void *cache)
{
-
- return (__vdso_getcpu_fallback(cpu, node, cache));
+ int ret;
+
+ if (node != NULL)
+ return (__vdso_getcpu_fallback(cpu, node, cache));
+ ret = __vdso_getcpu_try();
+ if (ret < 0)
+ return (__vdso_getcpu_fallback(cpu, node, cache));
+ *cpu = ret;
+ return (0);
}
#endif
diff --git a/sys/i386/linux/linux_sysvec.c b/sys/i386/linux/linux_sysvec.c
index 7bc7c96e943a..53e55557e6f7 100644
--- a/sys/i386/linux/linux_sysvec.c
+++ b/sys/i386/linux/linux_sysvec.c
@@ -160,6 +160,7 @@ LINUX_VDSO_SYM_INTPTR(__kernel_sigreturn);
LINUX_VDSO_SYM_INTPTR(__kernel_rt_sigreturn);
LINUX_VDSO_SYM_INTPTR(kern_timekeep_base);
LINUX_VDSO_SYM_INTPTR(kern_tsc_selector);
+LINUX_VDSO_SYM_INTPTR(kern_cpu_selector);
/*
* If FreeBSD & Linux have a difference of opinion about what a trap
@@ -942,6 +943,12 @@ linux_exec_sysvec_init(void *param)
*ktsc_selector = linux_vdso_tsc_selector_idx();
if (bootverbose)
printf("Linux i386 vDSO tsc_selector: %u\n", *ktsc_selector);
+
+ tkoff = kern_cpu_selector - linux_vdso_base;
+ ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff);
+ *ktsc_selector = linux_vdso_cpu_selector_idx();
+ if (bootverbose)
+ printf("Linux i386 vDSO cpu_selector: %u\n", *ktsc_selector);
}
SYSINIT(elf_linux_exec_sysvec_init, SI_SUB_EXEC + 1, SI_ORDER_ANY,
linux_exec_sysvec_init, &elf_linux_sysvec);
diff --git a/sys/i386/linux/linux_vdso.lds.s b/sys/i386/linux/linux_vdso.lds.s
index 0a392e6380b6..cd5b4a20dee0 100644
--- a/sys/i386/linux/linux_vdso.lds.s
+++ b/sys/i386/linux/linux_vdso.lds.s
@@ -58,6 +58,7 @@ VERSION
__vdso_clock_gettime;
__vdso_gettimeofday;
__vdso_time;
+ __vdso_getcpu;
__vdso_clock_getres;
__vdso_clock_gettime64;
};
@@ -75,6 +76,7 @@ VERSION
linux_platform;
kern_timekeep_base;
kern_tsc_selector;
+ kern_cpu_selector;
local: *;
};
}
diff --git a/sys/i386/linux/linux_vdso_gtod.c b/sys/i386/linux/linux_vdso_gtod.c
index 8619a21cd3f4..20f754bfaa17 100644
--- a/sys/i386/linux/linux_vdso_gtod.c
+++ b/sys/i386/linux/linux_vdso_gtod.c
@@ -49,8 +49,10 @@ __FBSDID("$FreeBSD$");
/* The kernel fixup this at vDSO install */
uintptr_t *kern_timekeep_base = NULL;
uint32_t kern_tsc_selector = 0;
+uint32_t kern_cpu_selector = 0;
#include <x86/linux/linux_vdso_gettc_x86.inc>
+#include <x86/linux/linux_vdso_getcpu_x86.inc>
static int
write(int fd, const void *buf, size_t size)
@@ -127,6 +129,21 @@ __vdso_clock_getres_fallback(clockid_t clock_id, struct l_timespec *ts)
return (res);
}
+static int
+__vdso_getcpu_fallback(uint32_t *cpu, uint32_t *node, void *cache)
+{
+ int res;
+
+ __asm__ __volatile__
+ (
+ "int $0x80"
+ : "=a"(res)
+ : "a"(LINUX_SYS_linux_getcpu), "D"(cpu), "S"(node), "d"(cache)
+ : "cc", "memory"
+ );
+ return (res);
+}
+
static int
__vdso_time_fallback(long *tm)
{
diff --git a/sys/modules/linux/Makefile b/sys/modules/linux/Makefile
index 9b4453045c09..b94605853743 100644
--- a/sys/modules/linux/Makefile
+++ b/sys/modules/linux/Makefile
@@ -20,7 +20,7 @@ SRCS= linux_fork.c linux${SFX}_dummy_machdep.c linux_file.c linux_event.c \
opt_inet6.h opt_compat.h opt_posix.h opt_usb.h vnode_if.h \
device_if.h bus_if.h
.if ${MACHINE_CPUARCH} == "i386" || ${MACHINE_CPUARCH} == "amd64"
-SRCS+= linux_dummy_x86.c linux_vdso_tsc_selector_x86.c
+SRCS+= linux_dummy_x86.c linux_vdso_selector_x86.c
VDSODEPS=linux_vdso_gettc_x86.inc
.endif
.if ${MACHINE_CPUARCH} == "amd64"
diff --git a/sys/modules/linux64/Makefile b/sys/modules/linux64/Makefile
index 4a4a84d38c73..63ddad878399 100644
--- a/sys/modules/linux64/Makefile
+++ b/sys/modules/linux64/Makefile
@@ -15,7 +15,7 @@ SRCS= linux_elf64.c linux_fork.c linux_dummy_machdep.c linux_file.c \
vnode_if.h device_if.h bus_if.h \
linux_support.s
.if ${MACHINE_CPUARCH} == "amd64"
-SRCS+= linux_dummy_x86.c linux_vdso_tsc_selector_x86.c
+SRCS+= linux_dummy_x86.c linux_vdso_selector_x86.c
.endif
DPSRCS= assym.inc linux_genassym.c
diff --git a/sys/x86/linux/linux_vdso_getcpu_x86.inc b/sys/x86/linux/linux_vdso_getcpu_x86.inc
new file mode 100644
index 000000000000..6cd0e5e78919
--- /dev/null
+++ b/sys/x86/linux/linux_vdso_getcpu_x86.inc
@@ -0,0 +1,68 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2021 The FreeBSD Foundation
+ * Copyright (c) 2022 Dmitry Chagin <dchagin@FreeBSD.org>
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 <x86/linux/linux_x86.h>
+
+static int
+__vdso_getcpu_rdpid(void)
+{
+ register_t res;
+
+ __asm("rdpid %0" : "=r" (res));
+ return ((int)res);
+}
+
+static int
+__vdso_getcpu_rdtscp(void)
+{
+ int res;
+
+ __asm("rdtscp" : "=c" (res) : : "eax", "edx");
+ return (res);
+}
+
+static int
+__vdso_getcpu_try(void)
+{
+ int res;
+
+ switch (kern_cpu_selector) {
+ case LINUX_VDSO_CPU_RDTSCP:
+ res = __vdso_getcpu_rdtscp();
+ break;
+ case LINUX_VDSO_CPU_RDPID:
+ res = __vdso_getcpu_rdpid();
+ break;
+ default:
+ res = -1;
+ }
+ return (res);
+}
diff --git a/sys/x86/linux/linux_vdso_tsc_selector_x86.c b/sys/x86/linux/linux_vdso_selector_x86.c
similarity index 79%
rename from sys/x86/linux/linux_vdso_tsc_selector_x86.c
rename to sys/x86/linux/linux_vdso_selector_x86.c
index a3a65a6d337d..d93b26ed44df 100644
--- a/sys/x86/linux/linux_vdso_tsc_selector_x86.c
+++ b/sys/x86/linux/linux_vdso_selector_x86.c
@@ -1,6 +1,6 @@
/*-
* Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org>
- * Copyright (c) 2016, 2017, 2019 The FreeBSD Foundation
+ * Copyright (c) 2016, 2017, 2019, 2021 The FreeBSD Foundation
* Copyright (c) 2021 Dmitry Chagin <dchagin@FreeBSD.org>
*
* Portions of this software were developed by Konstantin Belousov
@@ -36,6 +36,8 @@ __FBSDID("$FreeBSD$");
#include <x86/x86_var.h>
#include <x86/specialreg.h>
+#include <machine/cpufunc.h>
+
#include <x86/linux/linux_x86.h>
int
@@ -55,3 +57,25 @@ linux_vdso_tsc_selector_idx()
return (2);
return (amd_cpu ? 1 : 0);
}
+
+int
+linux_vdso_cpu_selector_idx()
+{
+ u_int amd_feature, cpu_exthigh, p[4];
+
+ if ((cpu_stdext_feature2 & CPUID_STDEXT2_RDPID) != 0)
+ return (LINUX_VDSO_CPU_RDPID);
+
+ amd_feature = 0;
+ if (cpu_feature != 0) {
+ do_cpuid(0x80000000, p);
+ cpu_exthigh = p[0];
+ if (cpu_exthigh >= 0x80000001) {
+ do_cpuid(0x80000001, p);
+ amd_feature = p[3];
+ }
+ }
+
+ return ((amd_feature & AMDID_RDTSCP) == 0 ?
+ LINUX_VDSO_CPU_DEFAULT : LINUX_VDSO_CPU_RDTSCP);
+}
diff --git a/sys/x86/linux/linux_x86.h b/sys/x86/linux/linux_x86.h
index 73736eb7eb84..79e6e7fbfeec 100644
--- a/sys/x86/linux/linux_x86.h
+++ b/sys/x86/linux/linux_x86.h
@@ -28,6 +28,11 @@
#ifndef _X86_INCLUDE_LINUX_LINUX_X86_H_
#define _X86_INCLUDE_LINUX_LINUX_X86_H_
+#define LINUX_VDSO_CPU_DEFAULT 0
+#define LINUX_VDSO_CPU_RDPID 1
+#define LINUX_VDSO_CPU_RDTSCP 2
+
int linux_vdso_tsc_selector_idx(void);
+int linux_vdso_cpu_selector_idx(void);
#endif /* _X86_INCLUDE_LINUX_LINUX_X86_H_ */