From d4f829dd9026797bd5db8715a30192f23b22afaa Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Tue, 23 Sep 2014 10:50:52 -0700 Subject: x86_64/vdso: Move getcpu code from vsyscall_64.c to vdso/vma.c This is pure cut-and-paste. At this point, vsyscall_64.c contains only code needed for vsyscall emulation, but some of the comments and function names are still confused. Signed-off-by: Andy Lutomirski Link: http://lkml.kernel.org/r/a244daf7d3cbe71afc08ad09fdfe1866ca1f1978.1411494540.git.luto@amacapital.net Signed-off-by: Ingo Molnar --- arch/x86/vdso/vma.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) (limited to 'arch/x86/vdso/vma.c') diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c index 970463b566cf..a155dca5edb5 100644 --- a/arch/x86/vdso/vma.c +++ b/arch/x86/vdso/vma.c @@ -10,12 +10,14 @@ #include #include #include +#include #include #include #include #include #include #include +#include #if defined(CONFIG_X86_64) unsigned int __read_mostly vdso64_enabled = 1; @@ -238,3 +240,62 @@ static __init int vdso_setup(char *s) } __setup("vdso=", vdso_setup); #endif + +#ifdef CONFIG_X86_64 +/* + * Assume __initcall executes before all user space. Hopefully kmod + * doesn't violate that. We'll find out if it does. + */ +static void vsyscall_set_cpu(int cpu) +{ + unsigned long d; + unsigned long node = 0; +#ifdef CONFIG_NUMA + node = cpu_to_node(cpu); +#endif + if (cpu_has(&cpu_data(cpu), X86_FEATURE_RDTSCP)) + write_rdtscp_aux((node << 12) | cpu); + + /* + * Store cpu number in limit so that it can be loaded quickly + * in user space in vgetcpu. (12 bits for the CPU and 8 bits for the node) + */ + d = 0x0f40000000000ULL; + d |= cpu; + d |= (node & 0xf) << 12; + d |= (node >> 4) << 48; + + write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_PER_CPU, &d, DESCTYPE_S); +} + +static void cpu_vsyscall_init(void *arg) +{ + /* preemption should be already off */ + vsyscall_set_cpu(raw_smp_processor_id()); +} + +static int +cpu_vsyscall_notifier(struct notifier_block *n, unsigned long action, void *arg) +{ + long cpu = (long)arg; + + if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN) + smp_call_function_single(cpu, cpu_vsyscall_init, NULL, 1); + + return NOTIFY_DONE; +} + +static int __init vsyscall_init(void) +{ + cpu_notifier_register_begin(); + + on_each_cpu(cpu_vsyscall_init, NULL, 1); + /* notifier priority > KVM */ + __hotcpu_notifier(cpu_vsyscall_notifier, 30); + + cpu_notifier_register_done(); + + return 0; +} +__initcall(vsyscall_init); +#endif -- cgit v1.2.3