xref: /openbmc/linux/arch/mips/include/uapi/asm/ucontext.h (revision e2c75e76)
1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 #ifndef __MIPS_UAPI_ASM_UCONTEXT_H
3 #define __MIPS_UAPI_ASM_UCONTEXT_H
4 
5 /**
6  * struct extcontext - extended context header structure
7  * @magic:	magic value identifying the type of extended context
8  * @size:	the size in bytes of the enclosing structure
9  *
10  * Extended context structures provide context which does not fit within struct
11  * sigcontext. They are placed sequentially in memory at the end of struct
12  * ucontext and struct sigframe, with each extended context structure beginning
13  * with a header defined by this struct. The type of context represented is
14  * indicated by the magic field. Userland may check each extended context
15  * structure against magic values that it recognises. The size field allows any
16  * unrecognised context to be skipped, allowing for future expansion. The end
17  * of the extended context data is indicated by the magic value
18  * END_EXTCONTEXT_MAGIC.
19  */
20 struct extcontext {
21 	unsigned int		magic;
22 	unsigned int		size;
23 };
24 
25 /**
26  * struct msa_extcontext - MSA extended context structure
27  * @ext:	the extended context header, with magic == MSA_EXTCONTEXT_MAGIC
28  * @wr:		the most significant 64 bits of each MSA vector register
29  * @csr:	the value of the MSA control & status register
30  *
31  * If MSA context is live for a task at the time a signal is delivered to it,
32  * this structure will hold the MSA context of the task as it was prior to the
33  * signal delivery.
34  */
35 struct msa_extcontext {
36 	struct extcontext	ext;
37 #define MSA_EXTCONTEXT_MAGIC	0x784d5341	/* xMSA */
38 
39 	unsigned long long	wr[32];
40 	unsigned int		csr;
41 };
42 
43 #define END_EXTCONTEXT_MAGIC	0x78454e44	/* xEND */
44 
45 /**
46  * struct ucontext - user context structure
47  * @uc_flags:
48  * @uc_link:
49  * @uc_stack:
50  * @uc_mcontext:	holds basic processor state
51  * @uc_sigmask:
52  * @uc_extcontext:	holds extended processor state
53  */
54 struct ucontext {
55 	/* Historic fields matching asm-generic */
56 	unsigned long		uc_flags;
57 	struct ucontext		*uc_link;
58 	stack_t			uc_stack;
59 	struct sigcontext	uc_mcontext;
60 	sigset_t		uc_sigmask;
61 
62 	/* Extended context structures may follow ucontext */
63 	unsigned long long	uc_extcontext[0];
64 };
65 
66 #endif /* __MIPS_UAPI_ASM_UCONTEXT_H */
67