/* * Copyright (C) 1994 Linus Torvalds * * Pentium III FXSR, SSE support * General FPU state handling cleanups * Gareth Hughes <gareth@valinux.com>, May 2000 * x86-64 work by Andi Kleen 2002 */ #ifndef _ASM_X86_FPU_API_H #define _ASM_X86_FPU_API_H /* * Careful: __kernel_fpu_begin/end() must be called with preempt disabled * and they don't touch the preempt state on their own. * If you enable preemption after __kernel_fpu_begin(), preempt notifier * should call the __kernel_fpu_end() to prevent the kernel/user FPU * state from getting corrupted. KVM for example uses this model. * * All other cases use kernel_fpu_begin/end() which disable preemption * during kernel FPU usage. */ extern void __kernel_fpu_begin(void); extern void __kernel_fpu_end(void); extern void kernel_fpu_begin(void); extern void kernel_fpu_end(void); extern bool irq_fpu_usable(void); /* * Some instructions like VIA's padlock instructions generate a spurious * DNA fault but don't modify SSE registers. And these instructions * get used from interrupt context as well. To prevent these kernel instructions * in interrupt context interacting wrongly with other user/kernel fpu usage, we * should use them only in the context of irq_ts_save/restore() */ extern int irq_ts_save(void); extern void irq_ts_restore(int TS_state); /* * Query the presence of one or more xfeatures. Works on any legacy CPU as well. * * If 'feature_name' is set then put a human-readable description of * the feature there as well - this can be used to print error (or success) * messages. */ extern int cpu_has_xfeatures(u64 xfeatures_mask, const char **feature_name); #endif /* _ASM_X86_FPU_API_H */Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp | |
| ingo molnar | ingo molnar | 41 | 53.25% | 8 | 57.14% |
| roland mcgrath | roland mcgrath | 15 | 19.48% | 1 | 7.14% |
| suresh siddha | suresh siddha | 10 | 12.99% | 3 | 21.43% |
| linus torvalds | linus torvalds | 9 | 11.69% | 1 | 7.14% |
| jaswinder singh rajput | jaswinder singh rajput | 2 | 2.60% | 1 | 7.14% |
| Total | 77 | 100.00% | 14 | 100.00% |