-/*
- * These must be called with preempt disabled. Returns
- * 'true' if the FPU state is still intact and we can
- * keep registers active.
- *
- * The legacy FNSAVE instruction cleared all FPU state
- * unconditionally, so registers are essentially destroyed.
- * Modern FPU state can be kept in registers, if there are
- * no pending FP exceptions.
- */
-static inline int copy_fpregs_to_fpstate(struct fpu *fpu)
-{
- if (likely(use_xsave())) {
- copy_xregs_to_kernel(&fpu->state.xsave);
-
- /*
- * AVX512 state is tracked here because its use is
- * known to slow the max clock speed of the core.
- */
- if (fpu->state.xsave.header.xfeatures & XFEATURE_MASK_AVX512)
- fpu->avx512_timestamp = jiffies;
- return 1;
- }
-
- if (likely(use_fxsr())) {
- copy_fxregs_to_kernel(fpu);
- return 1;
- }
-
- /*
- * Legacy FPU register saving, FNSAVE always clears FPU registers,
- * so we have to mark them inactive:
- */
- asm volatile("fnsave %[fp]; fwait" : [fp] "=m" (fpu->state.fsave));
-
- return 0;
-}