diff options
Diffstat (limited to 'arch/x86/kernel/fpu/core.c')
-rw-r--r-- | arch/x86/kernel/fpu/core.c | 74 |
1 files changed, 7 insertions, 67 deletions
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index ebb4e95fbd74..e4e97a5355ce 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -58,27 +58,9 @@ 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(); } /* @@ -125,8 +107,7 @@ void __kernel_fpu_begin(void) */ copy_fpregs_to_fpstate(fpu); } else { - this_cpu_write(fpu_fpregs_owner_ctx, NULL); - __fpregs_activate_hw(); + __cpu_invalidate_fpregs_state(); } } EXPORT_SYMBOL(__kernel_fpu_begin); @@ -137,8 +118,6 @@ void __kernel_fpu_end(void) if (fpu->fpregs_active) copy_kernel_to_fpregs(&fpu->state); - else - __fpregs_deactivate_hw(); kernel_fpu_enable(); } @@ -159,35 +138,6 @@ void kernel_fpu_end(void) EXPORT_SYMBOL_GPL(kernel_fpu_end); /* - * CR0::TS save/restore functions: - */ -int irq_ts_save(void) -{ - /* - * If in process context and not atomic, we can take a spurious DNA fault. - * Otherwise, doing clts() in process context requires disabling preemption - * or some heavy lifting like kernel_fpu_begin() - */ - if (!in_atomic()) - return 0; - - if (read_cr0() & X86_CR0_TS) { - clts(); - return 1; - } - - return 0; -} -EXPORT_SYMBOL_GPL(irq_ts_save); - -void irq_ts_restore(int TS_state) -{ - if (TS_state) - stts(); -} -EXPORT_SYMBOL_GPL(irq_ts_restore); - -/* * Save the FPU state (mark it for reload if necessary): * * This only ever gets called for the current task. @@ -200,10 +150,7 @@ 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); @@ -247,7 +194,6 @@ EXPORT_SYMBOL_GPL(fpstate_init); int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu) { - dst_fpu->counter = 0; dst_fpu->fpregs_active = 0; dst_fpu->last_cpu = -1; @@ -260,8 +206,7 @@ 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 @@ -283,10 +228,7 @@ 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(); @@ -366,7 +308,7 @@ void fpu__activate_fpstate_write(struct fpu *fpu) if (fpu->fpstate_active) { /* Invalidate any lazy state: */ - fpu->last_cpu = -1; + __fpu_invalidate_fpregs_state(fpu); } else { fpstate_init(&fpu->state); trace_x86_fpu_init_state(fpu); @@ -409,7 +351,7 @@ void fpu__current_fpstate_write_begin(void) * ensures we will not be lazy and skip a XRSTOR in the * future. */ - fpu->last_cpu = -1; + __fpu_invalidate_fpregs_state(fpu); } /* @@ -459,7 +401,6 @@ void fpu__restore(struct fpu *fpu) trace_x86_fpu_before_restore(fpu); fpregs_activate(fpu); copy_kernel_to_fpregs(&fpu->state); - fpu->counter++; trace_x86_fpu_after_restore(fpu); kernel_fpu_enable(); } @@ -477,7 +418,6 @@ EXPORT_SYMBOL_GPL(fpu__restore); void fpu__drop(struct fpu *fpu) { preempt_disable(); - fpu->counter = 0; if (fpu->fpregs_active) { /* Ignore delayed exceptions from user space */ |