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 XSTATE_CPUID 0x0000000d 16 17 #define TILE_CPUID 0x0000001d 18 19 #define FXSAVE_SIZE 512 20 21 #define XSAVE_HDR_SIZE 64 22 #define XSAVE_HDR_OFFSET FXSAVE_SIZE 23 24 #define XSAVE_YMM_SIZE 256 25 #define XSAVE_YMM_OFFSET (XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET) 26 27 #define XSAVE_ALIGNMENT 64 28 29 /* All currently supported user features */ 30 #define XFEATURE_MASK_USER_SUPPORTED (XFEATURE_MASK_FP | \ 31 XFEATURE_MASK_SSE | \ 32 XFEATURE_MASK_YMM | \ 33 XFEATURE_MASK_OPMASK | \ 34 XFEATURE_MASK_ZMM_Hi256 | \ 35 XFEATURE_MASK_Hi16_ZMM | \ 36 XFEATURE_MASK_PKRU | \ 37 XFEATURE_MASK_BNDREGS | \ 38 XFEATURE_MASK_BNDCSR | \ 39 XFEATURE_MASK_XTILE) 40 41 /* 42 * Features which are restored when returning to user space. 43 * PKRU is not restored on return to user space because PKRU 44 * is switched eagerly in switch_to() and flush_thread() 45 */ 46 #define XFEATURE_MASK_USER_RESTORE \ 47 (XFEATURE_MASK_USER_SUPPORTED & ~XFEATURE_MASK_PKRU) 48 49 /* Features which are dynamically enabled for a process on request */ 50 #define XFEATURE_MASK_USER_DYNAMIC XFEATURE_MASK_XTILE_DATA 51 52 /* All currently supported supervisor features */ 53 #define XFEATURE_MASK_SUPERVISOR_SUPPORTED (XFEATURE_MASK_PASID | \ 54 XFEATURE_MASK_CET_USER) 55 56 /* 57 * A supervisor state component may not always contain valuable information, 58 * and its size may be huge. Saving/restoring such supervisor state components 59 * at each context switch can cause high CPU and space overhead, which should 60 * be avoided. Such supervisor state components should only be saved/restored 61 * on demand. The on-demand supervisor features are set in this mask. 62 * 63 * Unlike the existing supported supervisor features, an independent supervisor 64 * feature does not allocate a buffer in task->fpu, and the corresponding 65 * supervisor state component cannot be saved/restored at each context switch. 66 * 67 * To support an independent supervisor feature, a developer should follow the 68 * dos and don'ts as below: 69 * - Do dynamically allocate a buffer for the supervisor state component. 70 * - Do manually invoke the XSAVES/XRSTORS instruction to save/restore the 71 * state component to/from the buffer. 72 * - Don't set the bit corresponding to the independent supervisor feature in 73 * IA32_XSS at run time, since it has been set at boot time. 74 */ 75 #define XFEATURE_MASK_INDEPENDENT (XFEATURE_MASK_LBR) 76 77 /* 78 * Unsupported supervisor features. When a supervisor feature in this mask is 79 * supported in the future, move it to the supported supervisor feature mask. 80 */ 81 #define XFEATURE_MASK_SUPERVISOR_UNSUPPORTED (XFEATURE_MASK_PT | \ 82 XFEATURE_MASK_CET_KERNEL) 83 84 /* All supervisor states including supported and unsupported states. */ 85 #define XFEATURE_MASK_SUPERVISOR_ALL (XFEATURE_MASK_SUPERVISOR_SUPPORTED | \ 86 XFEATURE_MASK_INDEPENDENT | \ 87 XFEATURE_MASK_SUPERVISOR_UNSUPPORTED) 88 89 /* 90 * The feature mask required to restore FPU state: 91 * - All user states which are not eagerly switched in switch_to()/exec() 92 * - The suporvisor states 93 */ 94 #define XFEATURE_MASK_FPSTATE (XFEATURE_MASK_USER_RESTORE | \ 95 XFEATURE_MASK_SUPERVISOR_SUPPORTED) 96 97 /* 98 * Features in this mask have space allocated in the signal frame, but may not 99 * have that space initialized when the feature is in its init state. 100 */ 101 #define XFEATURE_MASK_SIGFRAME_INITOPT (XFEATURE_MASK_XTILE | \ 102 XFEATURE_MASK_USER_DYNAMIC) 103 104 extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS]; 105 106 extern void __init update_regset_xstate_info(unsigned int size, 107 u64 xstate_mask); 108 109 int xfeature_size(int xfeature_nr); 110 111 void xsaves(struct xregs_state *xsave, u64 mask); 112 void xrstors(struct xregs_state *xsave, u64 mask); 113 114 int xfd_enable_feature(u64 xfd_err); 115 116 #ifdef CONFIG_X86_64 117 DECLARE_STATIC_KEY_FALSE(__fpu_state_size_dynamic); 118 #endif 119 120 #ifdef CONFIG_X86_64 121 DECLARE_STATIC_KEY_FALSE(__fpu_state_size_dynamic); 122 123 static __always_inline __pure bool fpu_state_size_dynamic(void) 124 { 125 return static_branch_unlikely(&__fpu_state_size_dynamic); 126 } 127 #else 128 static __always_inline __pure bool fpu_state_size_dynamic(void) 129 { 130 return false; 131 } 132 #endif 133 134 #endif 135