From ffebbaedc8616cffe648202e364dce6a045d65a2 Mon Sep 17 00:00:00 2001 From: "Chang S. Bae" Date: Tue, 18 Sep 2018 16:08:58 -0700 Subject: x86/vdso: Introduce helper functions for CPU and node number Clean up the CPU/node number related code a bit, to make it more apparent how we are encoding/extracting the CPU and node fields from the segment limit. No change in functionality intended. [ mingo: Wrote new changelog. ] Suggested-by: Andy Lutomirski Suggested-by: Thomas Gleixner Signed-off-by: Chang S. Bae Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Markus T Metzger Cc: Peter Zijlstra Cc: Ravi Shankar Cc: Rik van Riel Link: http://lkml.kernel.org/r/1537312139-5580-8-git-send-email-chang.seok.bae@intel.com Signed-off-by: Ingo Molnar --- arch/x86/entry/vdso/vgetcpu.c | 9 +-------- arch/x86/entry/vdso/vma.c | 19 +++++++------------ 2 files changed, 8 insertions(+), 20 deletions(-) (limited to 'arch/x86/entry') diff --git a/arch/x86/entry/vdso/vgetcpu.c b/arch/x86/entry/vdso/vgetcpu.c index 8ec3d1f4ce9a..de78fc9cd963 100644 --- a/arch/x86/entry/vdso/vgetcpu.c +++ b/arch/x86/entry/vdso/vgetcpu.c @@ -13,14 +13,7 @@ notrace long __vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused) { - unsigned int p; - - p = __getcpu(); - - if (cpu) - *cpu = p & VGETCPU_CPU_MASK; - if (node) - *node = p >> 12; + vdso_read_cpu_node(cpu, node); return 0; } diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c index 0b114aafcedc..39b5584c5808 100644 --- a/arch/x86/entry/vdso/vma.c +++ b/arch/x86/entry/vdso/vma.c @@ -339,20 +339,15 @@ static void vgetcpu_cpu_init(void *arg) { int cpu = smp_processor_id(); struct desc_struct d = { }; - unsigned long node = 0; -#ifdef CONFIG_NUMA - node = cpu_to_node(cpu); -#endif + unsigned long cpudata = vdso_encode_cpu_node(cpu, cpu_to_node(cpu)); + if (static_cpu_has(X86_FEATURE_RDTSCP)) - write_rdtscp_aux((node << 12) | cpu); + write_rdtscp_aux(cpudata); + + /* Store CPU and node number in limit */ + d.limit0 = cpudata; + d.limit1 = cpudata >> 16; - /* - * 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.limit0 = cpu | ((node & 0xf) << 12); - d.limit1 = node >> 4; d.type = 5; /* RO data, expand down, accessed */ d.dpl = 3; /* Visible to user code */ d.s = 1; /* Not a system segment */ -- cgit