Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756212Ab2K3XOm (ORCPT ); Fri, 30 Nov 2012 18:14:42 -0500 Received: from terminus.zytor.com ([198.137.202.10]:38739 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750854Ab2K3XOl (ORCPT ); Fri, 30 Nov 2012 18:14:41 -0500 Date: Fri, 30 Nov 2012 15:13:33 -0800 Message-Id: <201211302313.qAUNDXMK022697@terminus.zytor.com> From: "H. Peter Anvin" To: Linus Torvalds Subject: [GIT PULL] x86 fixes for 3.7 Cc: , Duncan Laurie , "H. Peter Anvin" , "H. Peter Anvin" , Ingo Molnar , Linux Kernel Mailing List , Marcelo Tosatti , Melanie Blower , Olof Johansson , Paolo Bonzini , Thomas Gleixner , Vincent Palatin X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.7 (terminus.zytor.com [127.0.0.1]); Fri, 30 Nov 2012 15:13:39 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4258 Lines: 119 Hi Linus, The following changes since commit 9489e9dcae718d5fde988e4a684a0f55b5f94d17: Linux 3.7-rc7 (2012-11-25 17:59:19 -0800) are available in the git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/urgent H. Peter Anvin (2): x86, kvm: Remove incorrect redundant assembly constraint x86-32: Unbreak booting on some 486 clones Vincent Palatin (1): x86, fpu: Avoid FPU lazy restore after suspend arch/x86/include/asm/fpu-internal.h | 15 +++++++++------ arch/x86/kernel/head_32.S | 9 +++++++-- arch/x86/kernel/smpboot.c | 5 +++++ arch/x86/kvm/emulate.c | 3 +-- 4 files changed, 22 insertions(+), 10 deletions(-) diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h index 831dbb9..41ab26e 100644 --- a/arch/x86/include/asm/fpu-internal.h +++ b/arch/x86/include/asm/fpu-internal.h @@ -399,14 +399,17 @@ static inline void drop_init_fpu(struct task_struct *tsk) typedef struct { int preload; } fpu_switch_t; /* - * FIXME! We could do a totally lazy restore, but we need to - * add a per-cpu "this was the task that last touched the FPU - * on this CPU" variable, and the task needs to have a "I last - * touched the FPU on this CPU" and check them. + * Must be run with preemption disabled: this clears the fpu_owner_task, + * on this CPU. * - * We don't do that yet, so "fpu_lazy_restore()" always returns - * false, but some day.. + * This will disable any lazy FPU state restore of the current FPU state, + * but if the current thread owns the FPU, it will still be saved by. */ +static inline void __cpu_disable_lazy_restore(unsigned int cpu) +{ + per_cpu(fpu_owner_task, cpu) = NULL; +} + static inline int fpu_lazy_restore(struct task_struct *new, unsigned int cpu) { return new == this_cpu_read_stable(fpu_owner_task) && diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index 957a47a..4dac2f6 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -292,8 +292,8 @@ default_entry: * be using the global pages. * * NOTE! If we are on a 486 we may have no cr4 at all! - * Specifically, cr4 exists if and only if CPUID exists, - * which in turn exists if and only if EFLAGS.ID exists. + * Specifically, cr4 exists if and only if CPUID exists + * and has flags other than the FPU flag set. */ movl $X86_EFLAGS_ID,%ecx pushl %ecx @@ -308,6 +308,11 @@ default_entry: testl %ecx,%eax jz 6f # No ID flag = no CPUID = no CR4 + movl $1,%eax + cpuid + andl $~1,%edx # Ignore CPUID.FPU + jz 6f # No flags or only CPUID.FPU = no CR4 + movl pa(mmu_cr4_features),%eax movl %eax,%cr4 diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index c80a33b..f3e2ec8 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -68,6 +68,8 @@ #include #include #include +#include +#include #include #include #include @@ -818,6 +820,9 @@ int __cpuinit native_cpu_up(unsigned int cpu, struct task_struct *tidle) per_cpu(cpu_state, cpu) = CPU_UP_PREPARE; + /* the FPU context is blank, nobody can own it */ + __cpu_disable_lazy_restore(cpu); + err = do_boot_cpu(apicid, cpu, tidle); if (err) { pr_debug("do_boot_cpu failed %d\n", err); diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 39171cb..bba39bf 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -426,8 +426,7 @@ static void invalidate_registers(struct x86_emulate_ctxt *ctxt) _ASM_EXTABLE(1b, 3b) \ : "=m" ((ctxt)->eflags), "=&r" (_tmp), \ "+a" (*rax), "+d" (*rdx), "+qm"(_ex) \ - : "i" (EFLAGS_MASK), "m" ((ctxt)->src.val), \ - "a" (*rax), "d" (*rdx)); \ + : "i" (EFLAGS_MASK), "m" ((ctxt)->src.val)); \ } while (0) /* instruction has only one source operand, destination is implicit (e.g. mul, div, imul, idiv) */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/