linux(4): Implement vdso getcpu for x86.

This is modeled after f2395455 (by kib@).

MFC after:		2 weeks

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)
@@ -129,6 +131,21 @@ __vdso_clock_getres_fallback(clockid_t clock_id, struct l_timespec *ts)
 }
 
 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)
 {
 	int res;
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)
@@ -128,6 +130,21 @@ __vdso_clock_getres_fallback(clockid_t clock_id, struct l_timespec *ts)
 }
 
 static int
+__vdso_getcpu_fallback(uint32_t *cpu, uint32_t *node, void *cache)
+{
+	int res;
+
+	__asm__ __volatile__
+	(
+	    "int $0x80"
+	    : "=a"(res)
+	    : "a"(LINUX_SYS_linux_getcpu), "D"(cpu), "S"(node), "d"(cache)
+	    : "cc", "memory"
+	);
+	return (res);
+}
+
+static int
 __vdso_time_fallback(long *tm)
 {
 	int res;
diff --git a/sys/modules/linux/Makefile b/sys/modules/linux/Makefile
index 9b4453045c09..b94605853743 100644
--- a/sys/modules/linux/Makefile
+++ b/sys/modules/linux/Makefile
@@ -20,7 +20,7 @@ SRCS=	linux_fork.c linux${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
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_ */