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); 118 119 static __always_inline __pure bool fpu_state_size_dynamic(void) 120 { 121 return static_branch_unlikely(&__fpu_state_size_dynamic); 122 } 123 #else 124 static __always_inline __pure bool fpu_state_size_dynamic(void) 125 { 126 return false; 127 } 128 #endif 129 130 #endif 131