1 /* SPDX-License-Identifier: GPL-2.0 */ 1
2 #ifndef __X86_KERNEL_FPU_CONTEXT_H
3 #define __X86_KERNEL_FPU_CONTEXT_H
4
5 #include <asm/fpu/xstate.h>
6 #include <asm/trace/fpu.h>
7
8 /* Functions related to FPU context tracking *
9
10 /*
11 * The in-register FPU state for an FPU contex
12 * valid if the fpu->last_cpu matches the CPU,
13 * matches the FPU.
14 *
15 * If the FPU register state is valid, the ker
16 * FPU state from memory.
17 *
18 * Any code that clobbers the FPU registers or
19 * FPU state for a task MUST let the rest of t
20 * FPU registers are no longer valid for this
21 *
22 * Invalidate a resource you control: CPU if u
23 * (with preemption disabled), FPU for the cur
24 * is prevented from running by the current ta
25 */
26 static inline void __cpu_invalidate_fpregs_sta
27 {
28 __this_cpu_write(fpu_fpregs_owner_ctx,
29 }
30
31 static inline void __fpu_invalidate_fpregs_sta
32 {
33 fpu->last_cpu = -1;
34 }
35
36 static inline int fpregs_state_valid(struct fp
37 {
38 return fpu == this_cpu_read(fpu_fpregs
39 }
40
41 static inline void fpregs_deactivate(struct fp
42 {
43 __this_cpu_write(fpu_fpregs_owner_ctx,
44 trace_x86_fpu_regs_deactivated(fpu);
45 }
46
47 static inline void fpregs_activate(struct fpu
48 {
49 __this_cpu_write(fpu_fpregs_owner_ctx,
50 trace_x86_fpu_regs_activated(fpu);
51 }
52
53 /* Internal helper for switch_fpu_return() and
54 static inline void fpregs_restore_userregs(voi
55 {
56 struct fpu *fpu = ¤t->thread.fpu
57 int cpu = smp_processor_id();
58
59 if (WARN_ON_ONCE(current->flags & (PF_
60 return;
61
62 if (!fpregs_state_valid(fpu, cpu)) {
63 /*
64 * This restores _all_ xstate
65 * established yet.
66 *
67 * If PKRU is enabled, then th
68 * correct because it was eith
69 * flush_thread(). So it is ex
70 * not up to date in current->
71 *
72 * XFD state is handled in res
73 */
74 restore_fpregs_from_fpstate(fp
75
76 fpregs_activate(fpu);
77 fpu->last_cpu = cpu;
78 }
79 clear_thread_flag(TIF_NEED_FPU_LOAD);
80 }
81
82 #endif
83
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