Commit-ID: b2e2ba578e016a091eb31565849990fe68c7c599 Gitweb: https://git.kernel.org/tip/b2e2ba578e016a091eb31565849990fe68c7c599 Author: Chang S. Bae <chang.seok....@intel.com> AuthorDate: Tue, 18 Sep 2018 16:08:59 -0700 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Mon, 8 Oct 2018 10:41:10 +0200
x86/vdso: Initialize the CPU/node NR segment descriptor earlier Currently the CPU/node NR segment descriptor (GDT_ENTRY_CPU_NUMBER) is initialized relatively late during CPU init, from the vCPU code, which has a number of disadvantages, such as hotplug CPU notifiers and SMP cross-calls. Instead just initialize it much earlier, directly in cpu_init(). This reduces complexity and increases robustness. [ mingo: Wrote new changelog. ] Suggested-by: H. Peter Anvin <h...@zytor.com> Suggested-by: Andy Lutomirski <l...@kernel.org> Signed-off-by: Chang S. Bae <chang.seok....@intel.com> Cc: Andy Lutomirski <l...@amacapital.net> Cc: Borislav Petkov <b...@alien8.de> Cc: Brian Gerst <brge...@gmail.com> Cc: Dave Hansen <dave.han...@linux.intel.com> Cc: Denys Vlasenko <dvlas...@redhat.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Markus T Metzger <markus.t.metz...@intel.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Ravi Shankar <ravi.v.shan...@intel.com> Cc: Rik van Riel <r...@surriel.com> Cc: Thomas Gleixner <t...@linutronix.de> Link: http://lkml.kernel.org/r/1537312139-5580-9-git-send-email-chang.seok....@intel.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/entry/vdso/vma.c | 33 +-------------------------------- arch/x86/kernel/cpu/common.c | 24 ++++++++++++++++++++++++ 2 files changed, 25 insertions(+), 32 deletions(-) diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c index 39b5584c5808..3f9d43f26f63 100644 --- a/arch/x86/entry/vdso/vma.c +++ b/arch/x86/entry/vdso/vma.c @@ -332,35 +332,6 @@ static __init int vdso_setup(char *s) return 0; } __setup("vdso=", vdso_setup); -#endif - -#ifdef CONFIG_X86_64 -static void vgetcpu_cpu_init(void *arg) -{ - int cpu = smp_processor_id(); - struct desc_struct d = { }; - unsigned long cpudata = vdso_encode_cpu_node(cpu, cpu_to_node(cpu)); - - if (static_cpu_has(X86_FEATURE_RDTSCP)) - write_rdtscp_aux(cpudata); - - /* Store CPU and node number in limit */ - d.limit0 = cpudata; - d.limit1 = cpudata >> 16; - - d.type = 5; /* RO data, expand down, accessed */ - d.dpl = 3; /* Visible to user code */ - d.s = 1; /* Not a system segment */ - d.p = 1; /* Present */ - d.d = 1; /* 32-bit */ - - write_gdt_entry(get_cpu_gdt_rw(cpu), GDT_ENTRY_CPU_NUMBER, &d, DESCTYPE_S); -} - -static int vgetcpu_online(unsigned int cpu) -{ - return smp_call_function_single(cpu, vgetcpu_cpu_init, NULL, 1); -} static int __init init_vdso(void) { @@ -370,9 +341,7 @@ static int __init init_vdso(void) init_vdso_image(&vdso_image_x32); #endif - /* notifier priority > KVM */ - return cpuhp_setup_state(CPUHP_AP_X86_VDSO_VMA_ONLINE, - "x86/vdso/vma:online", vgetcpu_online, NULL); + return 0; } subsys_initcall(init_vdso); #endif /* CONFIG_X86_64 */ diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 44c4ef3d989b..a148d18a1ef0 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1669,6 +1669,29 @@ static void wait_for_master_cpu(int cpu) #endif } +#ifdef CONFIG_X86_64 +static void setup_getcpu(int cpu) +{ + unsigned long cpudata = vdso_encode_cpu_node(cpu, early_cpu_to_node(cpu)); + struct desc_struct d = { }; + + if (static_cpu_has(X86_FEATURE_RDTSCP)) + write_rdtscp_aux(cpudata); + + /* Store CPU and node number in limit. */ + d.limit0 = cpudata; + d.limit1 = cpudata >> 16; + + d.type = 5; /* RO data, expand down, accessed */ + d.dpl = 3; /* Visible to user code */ + d.s = 1; /* Not a system segment */ + d.p = 1; /* Present */ + d.d = 1; /* 32-bit */ + + write_gdt_entry(get_cpu_gdt_rw(cpu), GDT_ENTRY_CPU_NUMBER, &d, DESCTYPE_S); +} +#endif + /* * cpu_init() initializes state that is per-CPU. Some data is already * initialized (naturally) in the bootstrap process, such as the GDT @@ -1706,6 +1729,7 @@ void cpu_init(void) early_cpu_to_node(cpu) != NUMA_NO_NODE) set_numa_node(early_cpu_to_node(cpu)); #endif + setup_getcpu(cpu); me = current;
