5 #include <asm/fpu/xstate.h>
6 #include <asm/trace/fpu.h>
8 /* Functions related to FPU context tracking */
11  * The in-register FPU state for an FPU context on a CPU is assumed to be
12  * valid if the fpu->last_cpu matches the CPU, and the fpu_fpregs_owner_ctx
13  * matches the FPU.
15  * If the FPU register state is valid, the kernel can skip restoring the
16  * FPU state from memory.
18  * Any code that clobbers the FPU registers or updates the in-memory
19  * FPU state for a task MUST let the rest of the kernel know that the
20  * FPU registers are no longer valid for this task.
23  * (with preemption disabled), FPU for the current task, or a task that
31 static inline void __fpu_invalidate_fpregs_state(struct fpu *fpu)  in __fpu_invalidate_fpregs_state()  argument
33 	fpu->last_cpu = -1;  in __fpu_invalidate_fpregs_state()
36 static inline int fpregs_state_valid(struct fpu *fpu, unsigned int cpu)  in fpregs_state_valid()  argument
38 	return fpu == this_cpu_read(fpu_fpregs_owner_ctx) && cpu == fpu->last_cpu;  in fpregs_state_valid()
41 static inline void fpregs_deactivate(struct fpu *fpu)  in fpregs_deactivate()  argument
44 	trace_x86_fpu_regs_deactivated(fpu);  in fpregs_deactivate()
47 static inline void fpregs_activate(struct fpu *fpu)  in fpregs_activate()  argument
49 	__this_cpu_write(fpu_fpregs_owner_ctx, fpu);  in fpregs_activate()
50 	trace_x86_fpu_regs_activated(fpu);  in fpregs_activate()
56 	struct fpu *fpu = &current->thread.fpu;  in fpregs_restore_userregs()  local
62 	if (!fpregs_state_valid(fpu, cpu)) {  in fpregs_restore_userregs()
70 		 * not up to date in current->thread.fpu.xsave state.  in fpregs_restore_userregs()
74 		restore_fpregs_from_fpstate(fpu->fpstate, XFEATURE_MASK_FPSTATE);  in fpregs_restore_userregs()
76 		fpregs_activate(fpu);  in fpregs_restore_userregs()
77 		fpu->last_cpu = cpu;  in fpregs_restore_userregs()