/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASMARM_UCONTEXT_H
#define _ASMARM_UCONTEXT_H

#include <asm/fpstate.h>
#include <asm/user.h>

/*
 * struct sigcontext only has room for the basic registers, but struct
 * ucontext now has room for all registers which need to be saved and
 * restored.  Coprocessor registers are stored in uc_regspace.  Each
 * coprocessor's saved state should start with a documented 32-bit magic
 * number, followed by a 32-bit word giving the coproccesor's saved size.
 * uc_regspace may be expanded if necessary, although this takes some
 * coordination with glibc.
 */

struct ucontext {
        unsigned long     uc_flags;
        struct ucontext  *uc_link;
        stack_t           uc_stack;
        struct sigcontext uc_mcontext;
        sigset_t          uc_sigmask;
        /* Allow for uc_sigmask growth.  Glibc uses a 1024-bit sigset_t.  */
        int               __unused[32 - (sizeof (sigset_t) / sizeof (int))];
        /* Last for extensibility.  Eight byte aligned because some
           coprocessors require eight byte alignment.  */
        unsigned long     uc_regspace[128] __attribute__((__aligned__(8)));
};

#ifdef __KERNEL__

/*
 * Coprocessor save state.  The magic values and specific
 * coprocessor's layouts are part of the userspace ABI.  Each one of
 * these should be a multiple of eight bytes and aligned to eight
 * bytes, to prevent unpredictable padding in the signal frame.
 */

/*
 * Dummy padding block: if this magic is encountered, the block should
 * be skipped using the corresponding size field.
 */
#define DUMMY_MAGIC             0xb0d9ed01

#ifdef CONFIG_IWMMXT
/* iwmmxt_area is 0x98 bytes long, preceded by 8 bytes of signature */
#define IWMMXT_MAGIC            0x12ef842a
#define IWMMXT_STORAGE_SIZE     (IWMMXT_SIZE + 8)

struct iwmmxt_sigframe {
        unsigned long   magic;
        unsigned long   size;
        struct iwmmxt_struct storage;
} __attribute__((__aligned__(8)));
#endif /* CONFIG_IWMMXT */

#ifdef CONFIG_VFP
#define VFP_MAGIC               0x56465001

struct vfp_sigframe
{
        unsigned long           magic;
        unsigned long           size;
        struct user_vfp         ufp;
        struct user_vfp_exc     ufp_exc;
} __attribute__((__aligned__(8)));

/*
 *  8 byte for magic and size, 264 byte for ufp, 12 bytes for ufp_exc,
 *  4 bytes padding.
 */
#define VFP_STORAGE_SIZE        sizeof(struct vfp_sigframe)

#endif /* CONFIG_VFP */

/*
 * Auxiliary signal frame.  This saves stuff like FP state.
 * The layout of this structure is not part of the user ABI,
 * because the config options aren't.  uc_regspace is really
 * one of these.
 */
struct aux_sigframe {
#ifdef CONFIG_IWMMXT
        struct iwmmxt_sigframe  iwmmxt;
#endif
#ifdef CONFIG_VFP
        struct vfp_sigframe     vfp;
#endif
        /* Something that isn't a valid magic number for any coprocessor.  */
        unsigned long           end_magic;
} __attribute__((__aligned__(8)));

#endif

#endif /* !_ASMARM_UCONTEXT_H */