diff options
author | Andy Lutomirski <luto@kernel.org> | 2016-10-05 02:34:33 +0200 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2016-10-07 11:14:36 +0200 |
commit | c592b57347069abfc0dcad3b3a302cf882602597 (patch) | |
tree | fc0989987e9cb3c960df9cd2eaf763c7fc2161fb /arch/x86/kernel/fpu | |
parent | x86/fpu: Remove the XFEATURE_MASK_EAGER/LAZY distinction (diff) | |
download | linux-c592b57347069abfc0dcad3b3a302cf882602597.tar.xz linux-c592b57347069abfc0dcad3b3a302cf882602597.zip |
x86/fpu: Remove use_eager_fpu()
This removes all the obvious code paths that depend on lazy FPU mode.
It shouldn't change the generated code at all.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: pbonzini@redhat.com
Link: http://lkml.kernel.org/r/1475627678-20788-5-git-send-email-riel@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/fpu')
-rw-r--r-- | arch/x86/kernel/fpu/core.c | 38 | ||||
-rw-r--r-- | arch/x86/kernel/fpu/signal.c | 8 | ||||
-rw-r--r-- | arch/x86/kernel/fpu/xstate.c | 9 |
3 files changed, 8 insertions, 47 deletions
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 3fc03a09a93b..036e14fe3b77 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -57,27 +57,9 @@ static bool kernel_fpu_disabled(void) return this_cpu_read(in_kernel_fpu); } -/* - * Were we in an interrupt that interrupted kernel mode? - * - * On others, we can do a kernel_fpu_begin/end() pair *ONLY* if that - * pair does nothing at all: the thread must not have fpu (so - * that we don't try to save the FPU state), and TS must - * be set (so that the clts/stts pair does nothing that is - * visible in the interrupted kernel thread). - * - * Except for the eagerfpu case when we return true; in the likely case - * the thread has FPU but we are not going to set/clear TS. - */ static bool interrupted_kernel_fpu_idle(void) { - if (kernel_fpu_disabled()) - return false; - - if (use_eager_fpu()) - return true; - - return !current->thread.fpu.fpregs_active && (read_cr0() & X86_CR0_TS); + return !kernel_fpu_disabled(); } /* @@ -125,7 +107,6 @@ void __kernel_fpu_begin(void) copy_fpregs_to_fpstate(fpu); } else { this_cpu_write(fpu_fpregs_owner_ctx, NULL); - __fpregs_activate_hw(); } } EXPORT_SYMBOL(__kernel_fpu_begin); @@ -136,8 +117,6 @@ void __kernel_fpu_end(void) if (fpu->fpregs_active) copy_kernel_to_fpregs(&fpu->state); - else - __fpregs_deactivate_hw(); kernel_fpu_enable(); } @@ -199,10 +178,7 @@ void fpu__save(struct fpu *fpu) trace_x86_fpu_before_save(fpu); if (fpu->fpregs_active) { if (!copy_fpregs_to_fpstate(fpu)) { - if (use_eager_fpu()) - copy_kernel_to_fpregs(&fpu->state); - else - fpregs_deactivate(fpu); + copy_kernel_to_fpregs(&fpu->state); } } trace_x86_fpu_after_save(fpu); @@ -259,8 +235,7 @@ int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu) * Don't let 'init optimized' areas of the XSAVE area * leak into the child task: */ - if (use_eager_fpu()) - memset(&dst_fpu->state.xsave, 0, fpu_kernel_xstate_size); + memset(&dst_fpu->state.xsave, 0, fpu_kernel_xstate_size); /* * Save current FPU registers directly into the child @@ -282,10 +257,7 @@ int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu) memcpy(&src_fpu->state, &dst_fpu->state, fpu_kernel_xstate_size); - if (use_eager_fpu()) - copy_kernel_to_fpregs(&src_fpu->state); - else - fpregs_deactivate(src_fpu); + copy_kernel_to_fpregs(&src_fpu->state); } preempt_enable(); @@ -517,7 +489,7 @@ void fpu__clear(struct fpu *fpu) { WARN_ON_FPU(fpu != ¤t->thread.fpu); /* Almost certainly an anomaly */ - if (!use_eager_fpu() || !static_cpu_has(X86_FEATURE_FPU)) { + if (!static_cpu_has(X86_FEATURE_FPU)) { /* FPU state will be reallocated lazily at the first use. */ fpu__drop(fpu); } else { diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index a184c210efba..83c23c230b4c 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/kernel/fpu/signal.c @@ -340,11 +340,9 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size) } fpu->fpstate_active = 1; - if (use_eager_fpu()) { - preempt_disable(); - fpu__restore(fpu); - preempt_enable(); - } + preempt_disable(); + fpu__restore(fpu); + preempt_enable(); return err; } else { diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 01567aa87503..76bc2a1a3a79 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -886,15 +886,6 @@ int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, */ if (!boot_cpu_has(X86_FEATURE_OSPKE)) return -EINVAL; - /* - * For most XSAVE components, this would be an arduous task: - * brining fpstate up to date with fpregs, updating fpstate, - * then re-populating fpregs. But, for components that are - * never lazily managed, we can just access the fpregs - * directly. PKRU is never managed lazily, so we can just - * manipulate it directly. Make sure it stays that way. - */ - WARN_ON_ONCE(!use_eager_fpu()); /* Set the bits we need in PKRU: */ if (init_val & PKEY_DISABLE_ACCESS) |