hrev53882 adds 1 changeset to branch 'master'
old head: b9db31f64981d81b429d741071bc5d1e5ad19eb2
new head: 073e295aa60bd911448adc5f30a09a271e798581
overview:
https://git.haiku-os.org/haiku/log/?qt=range&q=073e295aa60b+%5Eb9db31f64981
----------------------------------------------------------------------------
073e295aa60b: kernel/x86: stores cpu number in TSC_AUX if rdtscp is available
On modern x86, one can use __rdtscp to get the current cpu in userland.
Change-Id: I1767e379606230a75e4622637c7a5aed9cdf9ab0
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2248
Reviewed-by: Adrien Destugues <pulkomandy@xxxxxxxxx>
[ Jérôme Duval <jerome.duval@xxxxxxxxx> ]
----------------------------------------------------------------------------
Revision: hrev53882
Commit: 073e295aa60bd911448adc5f30a09a271e798581
URL: https://git.haiku-os.org/haiku/commit/?id=073e295aa60b
Author: Jérôme Duval <jerome.duval@xxxxxxxxx>
Date: Sun Feb 16 18:09:51 2020 UTC
Committer: waddlesplash <waddlesplash@xxxxxxxxx>
Commit-Date: Mon Feb 17 17:26:39 2020 UTC
----------------------------------------------------------------------------
4 files changed, 67 insertions(+)
headers/private/kernel/arch/x86/arch_cpu.h | 1 +
src/system/kernel/arch/x86/arch_cpu.cpp | 6 +++
src/tests/system/libroot/os/Jamfile | 4 ++
src/tests/system/libroot/os/get_cpu_num_test.cpp | 56 ++++++++++++++++++++
----------------------------------------------------------------------------
diff --git a/headers/private/kernel/arch/x86/arch_cpu.h
b/headers/private/kernel/arch/x86/arch_cpu.h
index 69d849da54..3748aef156 100644
--- a/headers/private/kernel/arch/x86/arch_cpu.h
+++ b/headers/private/kernel/arch/x86/arch_cpu.h
@@ -114,6 +114,7 @@
#define IA32_MSR_FS_BASE 0xc0000100
#define IA32_MSR_GS_BASE 0xc0000101
#define IA32_MSR_KERNEL_GS_BASE 0xc0000102
+#define IA32_MSR_TSC_AUX 0xc0000103
// K8 MSR registers
#define K8_MSR_IPM 0xc0010055
diff --git a/src/system/kernel/arch/x86/arch_cpu.cpp
b/src/system/kernel/arch/x86/arch_cpu.cpp
index 7f735b977d..cf833bb1cb 100644
--- a/src/system/kernel/arch/x86/arch_cpu.cpp
+++ b/src/system/kernel/arch/x86/arch_cpu.cpp
@@ -1145,6 +1145,12 @@ arch_cpu_init_percpu(kernel_args* args, int cpu)
gCpuIdleFunc = halt_idle;
}
+#ifdef __x86_64__
+ // if RDTSCP is available write cpu number in TSC_AUX
+ if (x86_check_feature(IA32_FEATURE_AMD_EXT_RDTSCP, FEATURE_EXT_AMD))
+ x86_write_msr(IA32_MSR_TSC_AUX, cpu);
+#endif
+
return __x86_patch_errata_percpu(cpu);
}
diff --git a/src/tests/system/libroot/os/Jamfile
b/src/tests/system/libroot/os/Jamfile
index 62007f620e..41f8d01280 100644
--- a/src/tests/system/libroot/os/Jamfile
+++ b/src/tests/system/libroot/os/Jamfile
@@ -24,6 +24,10 @@ SimpleTest system_watching_test :
system_watching_test.cpp
;
+SimpleTest get_cpu_num_test :
+ get_cpu_num_test.cpp
+;
+
# Tell Jam where to find these sources
SEARCH on [ FGristFiles
driver_settings.cpp
diff --git a/src/tests/system/libroot/os/get_cpu_num_test.cpp
b/src/tests/system/libroot/os/get_cpu_num_test.cpp
new file mode 100644
index 0000000000..922dbb0304
--- /dev/null
+++ b/src/tests/system/libroot/os/get_cpu_num_test.cpp
@@ -0,0 +1,56 @@
+/*
+ * Copyright 2020, Jérôme Duval, jerome.duval@xxxxxxxxx.
+ * Distributed under the terms of the MIT License.
+ */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <OS.h>
+
+#include <x86intrin.h>
+
+extern const char* __progname;
+
+
+static void
+print_usage(bool error)
+{
+ fprintf(error ? stderr : stdout,
+ "Usage: %s\n",
+ __progname);
+}
+
+
+static void
+print_usage_and_exit(bool error)
+{
+ print_usage(error);
+ exit(error ? 1 : 0);
+}
+
+
+int
+main(int argc, const char* const* argv)
+{
+
+ if (argc > 2)
+ print_usage_and_exit(true);
+
+ if (argc > 1) {
+ const char* arg = argv[1];
+ if (strcmp(arg, "-h") == 0 || strcmp(arg, "--help") == 0)
+ print_usage_and_exit(false);
+ }
+
+#ifdef __x86_64__
+ uint32 cpuNum;
+ __rdtscp(&cpuNum);
+ printf("%" B_PRIu32 "\n", cpuNum);
+ return 0;
+#else
+ return 1;
+#endif
+}
