1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_X86_XSAVE_H
3 #define __ASM_X86_XSAVE_H
4
5 #include <linux/uaccess.h>
6 #include <linux/types.h>
7
8 #include <asm/processor.h>
9 #include <asm/fpu/api.h>
10 #include <asm/user.h>
11
12 /* Bit 63 of XCR0 is reserved for future expansion */
13 #define XFEATURE_MASK_EXTEND (~(XFEATURE_MASK_FPSSE | (1ULL << 63)))
14
15 #define FXSAVE_SIZE 512
16
17 #define XSAVE_HDR_SIZE 64
18 #define XSAVE_HDR_OFFSET FXSAVE_SIZE
19
20 #define XSAVE_YMM_SIZE 256
21 #define XSAVE_YMM_OFFSET (XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET)
22
23 #define XSAVE_ALIGNMENT 64
24
25 /* All currently supported user features */
26 #define XFEATURE_MASK_USER_SUPPORTED (XFEATURE_MASK_FP | \
27 XFEATURE_MASK_SSE | \
28 XFEATURE_MASK_YMM | \
29 XFEATURE_MASK_OPMASK | \
30 XFEATURE_MASK_ZMM_Hi256 | \
31 XFEATURE_MASK_Hi16_ZMM | \
32 XFEATURE_MASK_PKRU | \
33 XFEATURE_MASK_BNDREGS | \
34 XFEATURE_MASK_BNDCSR | \
35 XFEATURE_MASK_XTILE)
36
37 /*
38 * Features which are restored when returning to user space.
39 * PKRU is not restored on return to user space because PKRU
40 * is switched eagerly in switch_to() and flush_thread()
41 */
42 #define XFEATURE_MASK_USER_RESTORE \
43 (XFEATURE_MASK_USER_SUPPORTED & ~XFEATURE_MASK_PKRU)
44
45 /* Features which are dynamically enabled for a process on request */
46 #define XFEATURE_MASK_USER_DYNAMIC XFEATURE_MASK_XTILE_DATA
47
48 /* All currently supported supervisor features */
49 #define XFEATURE_MASK_SUPERVISOR_SUPPORTED (XFEATURE_MASK_PASID | \
50 XFEATURE_MASK_CET_USER)
51
52 /*
53 * A supervisor state component may not always contain valuable information,
54 * and its size may be huge. Saving/restoring such supervisor state components
55 * at each context switch can cause high CPU and space overhead, which should
56 * be avoided. Such supervisor state components should only be saved/restored
57 * on demand. The on-demand supervisor features are set in this mask.
58 *
59 * Unlike the existing supported supervisor features, an independent supervisor
60 * feature does not allocate a buffer in task->fpu, and the corresponding
61 * supervisor state component cannot be saved/restored at each context switch.
62 *
63 * To support an independent supervisor feature, a developer should follow the
64 * dos and don'ts as below:
65 * - Do dynamically allocate a buffer for the supervisor state component.
66 * - Do manually invoke the XSAVES/XRSTORS instruction to save/restore the
67 * state component to/from the buffer.
68 * - Don't set the bit corresponding to the independent supervisor feature in
69 * IA32_XSS at run time, since it has been set at boot time.
70 */
71 #define XFEATURE_MASK_INDEPENDENT (XFEATURE_MASK_LBR)
72
73 /*
74 * Unsupported supervisor features. When a supervisor feature in this mask is
75 * supported in the future, move it to the supported supervisor feature mask.
76 */
77 #define XFEATURE_MASK_SUPERVISOR_UNSUPPORTED (XFEATURE_MASK_PT | \
78 XFEATURE_MASK_CET_KERNEL)
79
80 /* All supervisor states including supported and unsupported states. */
81 #define XFEATURE_MASK_SUPERVISOR_ALL (XFEATURE_MASK_SUPERVISOR_SUPPORTED | \
82 XFEATURE_MASK_INDEPENDENT | \
83 XFEATURE_MASK_SUPERVISOR_UNSUPPORTED)
84
85 /*
86 * The feature mask required to restore FPU state:
87 * - All user states which are not eagerly switched in switch_to()/exec()
88 * - The suporvisor states
89 */
90 #define XFEATURE_MASK_FPSTATE (XFEATURE_MASK_USER_RESTORE | \
91 XFEATURE_MASK_SUPERVISOR_SUPPORTED)
92
93 /*
94 * Features in this mask have space allocated in the signal frame, but may not
95 * have that space initialized when the feature is in its init state.
96 */
97 #define XFEATURE_MASK_SIGFRAME_INITOPT (XFEATURE_MASK_XTILE | \
98 XFEATURE_MASK_USER_DYNAMIC)
99
100 extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
101
102 extern void __init update_regset_xstate_info(unsigned int size,
103 u64 xstate_mask);
104
105 int xfeature_size(int xfeature_nr);
106
107 void xsaves(struct xregs_state *xsave, u64 mask);
108 void xrstors(struct xregs_state *xsave, u64 mask);
109
110 int xfd_enable_feature(u64 xfd_err);
111
112 #ifdef CONFIG_X86_64
113 DECLARE_STATIC_KEY_FALSE(__fpu_state_size_dynamic);
114 #endif
115
116 #ifdef CONFIG_X86_64
117 DECLARE_STATIC_KEY_FALSE(__fpu_state_size_dynamic);
118
fpu_state_size_dynamic(void)119 static __always_inline __pure bool fpu_state_size_dynamic(void)
120 {
121 return static_branch_unlikely(&__fpu_state_size_dynamic);
122 }
123 #else
fpu_state_size_dynamic(void)124 static __always_inline __pure bool fpu_state_size_dynamic(void)
125 {
126 return false;
127 }
128 #endif
129
130 #endif
131