xref: /openbmc/linux/arch/x86/include/asm/user.h (revision feac8c8b)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_USER_H
3 #define _ASM_X86_USER_H
4 
5 #ifdef CONFIG_X86_32
6 # include <asm/user_32.h>
7 #else
8 # include <asm/user_64.h>
9 #endif
10 
11 #include <asm/types.h>
12 
13 struct user_ymmh_regs {
14 	/* 16 * 16 bytes for each YMMH-reg */
15 	__u32 ymmh_space[64];
16 };
17 
18 struct user_xstate_header {
19 	__u64 xfeatures;
20 	__u64 reserved1[2];
21 	__u64 reserved2[5];
22 };
23 
24 /*
25  * The structure layout of user_xstateregs, used for exporting the
26  * extended register state through ptrace and core-dump (NT_X86_XSTATE note)
27  * interfaces will be same as the memory layout of xsave used by the processor
28  * (except for the bytes 464..511, which can be used by the software) and hence
29  * the size of this structure varies depending on the features supported by the
30  * processor and OS. The size of the structure that users need to use can be
31  * obtained by doing:
32  *     cpuid_count(0xd, 0, &eax, &ptrace_xstateregs_struct_size, &ecx, &edx);
33  * i.e., cpuid.(eax=0xd,ecx=0).ebx will be the size that user (debuggers, etc.)
34  * need to use.
35  *
36  * For now, only the first 8 bytes of the software usable bytes[464..471] will
37  * be used and will be set to OS enabled xstate mask (which is same as the
38  * 64bit mask returned by the xgetbv's xCR0).  Users (analyzing core dump
39  * remotely, etc.) can use this mask as well as the mask saved in the
40  * xstate_hdr bytes and interpret what states the processor/OS supports
41  * and what states are in modified/initialized conditions for the
42  * particular process/thread.
43  *
44  * Also when the user modifies certain state FP/SSE/etc through the
45  * ptrace interface, they must ensure that the header.xfeatures
46  * bytes[512..519] of the memory layout are updated correspondingly.
47  * i.e., for example when FP state is modified to a non-init state,
48  * header.xfeatures's bit 0 must be set to '1', when SSE is modified to
49  * non-init state, header.xfeatures's bit 1 must to be set to '1', etc.
50  */
51 #define USER_XSTATE_FX_SW_WORDS 6
52 #define USER_XSTATE_XCR0_WORD	0
53 
54 struct user_xstateregs {
55 	struct {
56 		__u64 fpx_space[58];
57 		__u64 xstate_fx_sw[USER_XSTATE_FX_SW_WORDS];
58 	} i387;
59 	struct user_xstate_header header;
60 	struct user_ymmh_regs ymmh;
61 	/* further processor state extensions go here */
62 };
63 
64 #endif /* _ASM_X86_USER_H */
65