Messages in this thread Patch in this message | | | From | Andy Lutomirski <> | Subject | [PATCH 8/8] x86,vdso: Replace vgetcpu_mode with static_cpu_has | Date | Tue, 23 Sep 2014 10:50:58 -0700 |
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The vdso has supported alternatives for a while; use them instead of a vvar to select the vgetcpu mode.
Signed-off-by: Andy Lutomirski <luto@amacapital.net> --- arch/x86/include/asm/vgtod.h | 21 +++++++++++++++++++++ arch/x86/include/asm/vsyscall.h | 29 ----------------------------- arch/x86/include/asm/vvar.h | 1 - arch/x86/kernel/cpu/common.c | 10 ---------- arch/x86/kernel/vsyscall_64.c | 2 -- arch/x86/vdso/vclock_gettime.c | 3 +++ arch/x86/vdso/vgetcpu.c | 4 +++- 7 files changed, 27 insertions(+), 43 deletions(-)
diff --git a/arch/x86/include/asm/vgtod.h b/arch/x86/include/asm/vgtod.h index 3c3366c2e37f..44e00370c438 100644 --- a/arch/x86/include/asm/vgtod.h +++ b/arch/x86/include/asm/vgtod.h @@ -70,4 +70,25 @@ static inline void gtod_write_end(struct vsyscall_gtod_data *s) ++s->seq; } +#ifdef CONFIG_X86_64 + +#define VGETCPU_CPU_MASK 0xfff + +static inline unsigned int __getcpu(void) +{ + unsigned int p; + + if (static_cpu_has(X86_FEATURE_RDTSCP)) { + /* Load per CPU data from RDTSCP */ + native_read_tscp(&p); + } else { + /* Load per CPU data from GDT */ + asm("lsl %1,%0" : "=r" (p) : "r" (__PER_CPU_SEG)); + } + + return p; +} + +#endif /* CONFIG_X86_64 */ + #endif /* _ASM_X86_VGTOD_H */ diff --git a/arch/x86/include/asm/vsyscall.h b/arch/x86/include/asm/vsyscall.h index 2a46ca720afc..34f7d8857542 100644 --- a/arch/x86/include/asm/vsyscall.h +++ b/arch/x86/include/asm/vsyscall.h @@ -4,15 +4,6 @@ #include <linux/seqlock.h> #include <uapi/asm/vsyscall.h> -#define VGETCPU_RDTSCP 1 -#define VGETCPU_LSL 2 - -/* kernel space (writeable) */ -extern int vgetcpu_mode; -extern struct timezone sys_tz; - -#include <asm/vvar.h> - extern void map_vsyscall(void); /* @@ -21,24 +12,4 @@ extern void map_vsyscall(void); */ extern bool emulate_vsyscall(struct pt_regs *regs, unsigned long address); -#ifdef CONFIG_X86_64 - -#define VGETCPU_CPU_MASK 0xfff - -static inline unsigned int __getcpu(void) -{ - unsigned int p; - - if (VVAR(vgetcpu_mode) == VGETCPU_RDTSCP) { - /* Load per CPU data from RDTSCP */ - native_read_tscp(&p); - } else { - /* Load per CPU data from GDT */ - asm("lsl %1,%0" : "=r" (p) : "r" (__PER_CPU_SEG)); - } - - return p; -} -#endif /* CONFIG_X86_64 */ - #endif /* _ASM_X86_VSYSCALL_H */ diff --git a/arch/x86/include/asm/vvar.h b/arch/x86/include/asm/vvar.h index 5f6d40734a3b..3f32dfc2ab73 100644 --- a/arch/x86/include/asm/vvar.h +++ b/arch/x86/include/asm/vvar.h @@ -44,7 +44,6 @@ extern char __vvar_page; /* DECLARE_VVAR(offset, type, name) */ -DECLARE_VVAR(16, int, vgetcpu_mode) DECLARE_VVAR(128, struct vsyscall_gtod_data, vsyscall_gtod_data) #undef DECLARE_VVAR diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index e4ab2b42bd6f..c12b864c9d98 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -956,14 +956,6 @@ static void identify_cpu(struct cpuinfo_x86 *c) } #ifdef CONFIG_X86_64 -static void vgetcpu_set_mode(void) -{ - if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP)) - vgetcpu_mode = VGETCPU_RDTSCP; - else - vgetcpu_mode = VGETCPU_LSL; -} - /* May not be __init: called during resume */ static void syscall32_cpu_init(void) { @@ -1004,8 +996,6 @@ void __init identify_boot_cpu(void) #ifdef CONFIG_X86_32 sysenter_setup(); enable_sep_cpu(); -#else - vgetcpu_set_mode(); #endif cpu_detect_tlb(&boot_cpu_data); } diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c index 31ce584981f3..9d2c660cfb70 100644 --- a/arch/x86/kernel/vsyscall_64.c +++ b/arch/x86/kernel/vsyscall_64.c @@ -52,8 +52,6 @@ #define CREATE_TRACE_POINTS #include "vsyscall_trace.h" -DEFINE_VVAR(int, vgetcpu_mode); - static enum { EMULATE, NATIVE, NONE } vsyscall_mode = EMULATE; static int __init vsyscall_setup(char *str) diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c index 9793322751e0..d14bb8faad16 100644 --- a/arch/x86/vdso/vclock_gettime.c +++ b/arch/x86/vdso/vclock_gettime.c @@ -11,6 +11,9 @@ * Check with readelf after changing. */ +/* Disable static_cpu_has debugging; it doesn't work in the vDSO */ +#undef CONFIG_X86_DEBUG_STATIC_CPU_HAS + #include <uapi/linux/time.h> #include <asm/vgtod.h> #include <asm/hpet.h> diff --git a/arch/x86/vdso/vgetcpu.c b/arch/x86/vdso/vgetcpu.c index add1d98d2477..fd8470c98ab5 100644 --- a/arch/x86/vdso/vgetcpu.c +++ b/arch/x86/vdso/vgetcpu.c @@ -5,10 +5,12 @@ * Fast user context implementation of getcpu() */ +/* Disable static_cpu_has debugging; it doesn't work in the vDSO */ +#undef CONFIG_X86_DEBUG_STATIC_CPU_HAS + #include <linux/kernel.h> #include <linux/getcpu.h> #include <linux/time.h> -#include <asm/vsyscall.h> #include <asm/vgtod.h> notrace long -- 1.9.3
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