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/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
* Copyright (C) 2012 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef _UAPI__ASM_SIGCONTEXT_H
#define _UAPI__ASM_SIGCONTEXT_H
#ifndef __ASSEMBLY__
#include <linux/types.h>
/*
* Signal context structure - contains all info to do with the state
* before the signal handler was invoked.
*/
struct sigcontext {
__u64 fault_address;
/* AArch64 registers */
__u64 regs[31];
__u64 sp;
__u64 pc;
__u64 pstate;
/* 4K reserved for FP/SIMD state and future expansion */
__u8 __reserved[4096] __attribute__((__aligned__(16)));
};
/*
* Allocation of __reserved[]:
* (Note: records do not necessarily occur in the order shown here.)
*
* size description
*
* 0x210 fpsimd_context
* 0x10 esr_context
* 0x8a0 sve_context (vl <= 64) (optional)
* 0x20 extra_context (optional)
* 0x10 terminator (null _aarch64_ctx)
*
* 0x510 (reserved for future allocation)
*
* New records that can exceed this space need to be opt-in for userspace, so
* that an expanded signal frame is not generated unexpectedly. The mechanism
* for opting in will depend on the extension that generates each new record.
* The above table documents the maximum set and sizes of records than can be
* generated when userspace does not opt in for any such extension.
*/
/*
* Header to be used at the beginning of structures extending the user
* context. Such structures must be placed after the rt_sigframe on the stack
* and be 16-byte aligned. The last structure must be a dummy one with the
* magic and size set to 0.
*/
struct _aarch64_ctx {
__u32 magic;
__u32 size;
};
#define FPSIMD_MAGIC 0x46508001
struct fpsimd_context {
struct _aarch64_ctx head;
__u32 fpsr;
__u32 fpcr;
__uint128_t vregs[32];
};
/* ESR_EL1 context */
#define ESR_MAGIC 0x45535201
struct esr_context {
struct _aarch64_ctx head;
__u64 esr;
};
/*
* extra_context: describes extra space in the signal frame for
* additional structures that don't fit in sigcontext.__reserved[].
*
* Note:
*
* 1) fpsimd_context, esr_context and extra_context must be placed in
* sigcontext.__reserved[] if present. They cannot be placed in the
* extra space. Any other record can be placed either in the extra
* space or in sigcontext.__reserved[], unless otherwise specified in
* this file.
*
* 2) There must not be more than one extra_context.
*
* 3) If extra_context is present, it must be followed immediately in
* sigcontext.__reserved[] by the terminating null _aarch64_ctx.
*
* 4) The extra space to which datap points must start at the first
* 16-byte aligned address immediately after the terminating null
* _aarch64_ctx that follows the extra_context structure in
* __reserved[]. The extra space may overrun the end of __reserved[],
* as indicated by a sufficiently large value for the size field.
*
* 5) The extra space must itself be terminated with a null
* _aarch64_ctx.
*/
#define EXTRA_MAGIC 0x45585401
struct extra_context {
struct _aarch64_ctx head;
__u64 datap; /* 16-byte aligned pointer to extra space cast to __u64 */
__u32 size; /* size in bytes of the extra space */
__u32 __reserved[3];
};
#define SVE_MAGIC 0x53564501
struct sve_context {
struct _aarch64_ctx head;
__u16 vl;
__u16 __reserved[3];
};
#endif /* !__ASSEMBLY__ */
/*
* The SVE architecture leaves space for future expansion of the
* vector length beyond its initial architectural limit of 2048 bits
* (16 quadwords).
*
* See linux/Documentation/arm64/sve.txt for a description of the VL/VQ
* terminology.
*/
#define SVE_VQ_BYTES 16 /* number of bytes per quadword */
#define SVE_VQ_MIN 1
#define SVE_VQ_MAX 512
#define SVE_VL_MIN (SVE_VQ_MIN * SVE_VQ_BYTES)
#define SVE_VL_MAX (SVE_VQ_MAX * SVE_VQ_BYTES)
#define SVE_NUM_ZREGS 32
#define SVE_NUM_PREGS 16
#define sve_vl_valid(vl) \
((vl) % SVE_VQ_BYTES == 0 && (vl) >= SVE_VL_MIN && (vl) <= SVE_VL_MAX)
#define sve_vq_from_vl(vl) ((vl) / SVE_VQ_BYTES)
#define sve_vl_from_vq(vq) ((vq) * SVE_VQ_BYTES)
/*
* If the SVE registers are currently live for the thread at signal delivery,
* sve_context.head.size >=
* SVE_SIG_CONTEXT_SIZE(sve_vq_from_vl(sve_context.vl))
* and the register data may be accessed using the SVE_SIG_*() macros.
*
* If sve_context.head.size <
* SVE_SIG_CONTEXT_SIZE(sve_vq_from_vl(sve_context.vl)),
* the SVE registers were not live for the thread and no register data
* is included: in this case, the SVE_SIG_*() macros should not be
* used except for this check.
*
* The same convention applies when returning from a signal: a caller
* will need to remove or resize the sve_context block if it wants to
* make the SVE registers live when they were previously non-live or
* vice-versa. This may require the the caller to allocate fresh
* memory and/or move other context blocks in the signal frame.
*
* Changing the vector length during signal return is not permitted:
* sve_context.vl must equal the thread's current vector length when
* doing a sigreturn.
*
*
* Note: for all these macros, the "vq" argument denotes the SVE
* vector length in quadwords (i.e., units of 128 bits).
*
* The correct way to obtain vq is to use sve_vq_from_vl(vl). The
* result is valid if and only if sve_vl_valid(vl) is true. This is
* guaranteed for a struct sve_context written by the kernel.
*
*
* Additional macros describe the contents and layout of the payload.
* For each, SVE_SIG_x_OFFSET(args) is the start offset relative to
* the start of struct sve_context, and SVE_SIG_x_SIZE(args) is the
* size in bytes:
*
* x type description
* - ---- -----------
* REGS the entire SVE context
*
* ZREGS __uint128_t[SVE_NUM_ZREGS][vq] all Z-registers
* ZREG __uint128_t[vq] individual Z-register Zn
*
* PREGS uint16_t[SVE_NUM_PREGS][vq] all P-registers
* PREG uint16_t[vq] individual P-register Pn
*
* FFR uint16_t[vq] first-fault status register
*
* Additional data might be appended in the future.
*/
#define SVE_SIG_ZREG_SIZE(vq) ((__u32)(vq) * SVE_VQ_BYTES)
#define SVE_SIG_PREG_SIZE(vq) ((__u32)(vq) * (SVE_VQ_BYTES / 8))
#define SVE_SIG_FFR_SIZE(vq) SVE_SIG_PREG_SIZE(vq)
#define SVE_SIG_REGS_OFFSET \
((sizeof(struct sve_context) + (SVE_VQ_BYTES - 1)) \
/ SVE_VQ_BYTES * SVE_VQ_BYTES)
#define SVE_SIG_ZREGS_OFFSET SVE_SIG_REGS_OFFSET
#define SVE_SIG_ZREG_OFFSET(vq, n) \
(SVE_SIG_ZREGS_OFFSET + SVE_SIG_ZREG_SIZE(vq) * (n))
#define SVE_SIG_ZREGS_SIZE(vq) \
(SVE_SIG_ZREG_OFFSET(vq, SVE_NUM_ZREGS) - SVE_SIG_ZREGS_OFFSET)
#define SVE_SIG_PREGS_OFFSET(vq) \
(SVE_SIG_ZREGS_OFFSET + SVE_SIG_ZREGS_SIZE(vq))
#define SVE_SIG_PREG_OFFSET(vq, n) \
(SVE_SIG_PREGS_OFFSET(vq) + SVE_SIG_PREG_SIZE(vq) * (n))
#define SVE_SIG_PREGS_SIZE(vq) \
(SVE_SIG_PREG_OFFSET(vq, SVE_NUM_PREGS) - SVE_SIG_PREGS_OFFSET(vq))
#define SVE_SIG_FFR_OFFSET(vq) \
(SVE_SIG_PREGS_OFFSET(vq) + SVE_SIG_PREGS_SIZE(vq))
#define SVE_SIG_REGS_SIZE(vq) \
(SVE_SIG_FFR_OFFSET(vq) + SVE_SIG_FFR_SIZE(vq) - SVE_SIG_REGS_OFFSET)
#define SVE_SIG_CONTEXT_SIZE(vq) (SVE_SIG_REGS_OFFSET + SVE_SIG_REGS_SIZE(vq))
#endif /* _UAPI__ASM_SIGCONTEXT_H */
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