1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
3 * Copyright (C) 2012 ARM Ltd.
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
17 #ifndef _UAPI__ASM_SIGCONTEXT_H
18 #define _UAPI__ASM_SIGCONTEXT_H
22 #include <linux/types.h>
25 * Signal context structure - contains all info to do with the state
26 * before the signal handler was invoked.
30 /* AArch64 registers */
35 /* 4K reserved for FP/SIMD state and future expansion */
36 __u8 __reserved[4096] __attribute__((__aligned__(16)));
40 * Allocation of __reserved[]:
41 * (Note: records do not necessarily occur in the order shown here.)
45 * 0x210 fpsimd_context
47 * 0x8a0 sve_context (vl <= 64) (optional)
48 * 0x20 extra_context (optional)
49 * 0x10 terminator (null _aarch64_ctx)
51 * 0x510 (reserved for future allocation)
53 * New records that can exceed this space need to be opt-in for userspace, so
54 * that an expanded signal frame is not generated unexpectedly. The mechanism
55 * for opting in will depend on the extension that generates each new record.
56 * The above table documents the maximum set and sizes of records than can be
57 * generated when userspace does not opt in for any such extension.
61 * Header to be used at the beginning of structures extending the user
62 * context. Such structures must be placed after the rt_sigframe on the stack
63 * and be 16-byte aligned. The last structure must be a dummy one with the
64 * magic and size set to 0.
66 * Note that the values allocated for use as magic should be chosen to
67 * be meaningful in ASCII to aid manual parsing, ZA doesn't follow this
68 * convention due to oversight but it should be observed for future additions.
75 #define FPSIMD_MAGIC 0x46508001
77 struct fpsimd_context {
78 struct _aarch64_ctx head;
81 __uint128_t vregs[32];
85 * Note: similarly to all other integer fields, each V-register is stored in an
86 * endianness-dependent format, with the byte at offset i from the start of the
87 * in-memory representation of the register value containing
89 * bits [(7 + 8 * i) : (8 * i)] of the register on little-endian hosts; or
90 * bits [(127 - 8 * i) : (120 - 8 * i)] on big-endian hosts.
94 #define ESR_MAGIC 0x45535201
97 struct _aarch64_ctx head;
102 * extra_context: describes extra space in the signal frame for
103 * additional structures that don't fit in sigcontext.__reserved[].
107 * 1) fpsimd_context, esr_context and extra_context must be placed in
108 * sigcontext.__reserved[] if present. They cannot be placed in the
109 * extra space. Any other record can be placed either in the extra
110 * space or in sigcontext.__reserved[], unless otherwise specified in
113 * 2) There must not be more than one extra_context.
115 * 3) If extra_context is present, it must be followed immediately in
116 * sigcontext.__reserved[] by the terminating null _aarch64_ctx.
118 * 4) The extra space to which datap points must start at the first
119 * 16-byte aligned address immediately after the terminating null
120 * _aarch64_ctx that follows the extra_context structure in
121 * __reserved[]. The extra space may overrun the end of __reserved[],
122 * as indicated by a sufficiently large value for the size field.
124 * 5) The extra space must itself be terminated with a null
127 #define EXTRA_MAGIC 0x45585401
129 struct extra_context {
130 struct _aarch64_ctx head;
131 __u64 datap; /* 16-byte aligned pointer to extra space cast to __u64 */
132 __u32 size; /* size in bytes of the extra space */
136 #define SVE_MAGIC 0x53564501
139 struct _aarch64_ctx head;
145 #define SVE_SIG_FLAG_SM 0x1 /* Context describes streaming mode */
147 /* TPIDR2_EL0 context */
148 #define TPIDR2_MAGIC 0x54504902
150 struct tpidr2_context {
151 struct _aarch64_ctx head;
155 #define ZA_MAGIC 0x54366345
158 struct _aarch64_ctx head;
163 #define ZT_MAGIC 0x5a544e01
166 struct _aarch64_ctx head;
171 #endif /* !__ASSEMBLY__ */
173 #include <asm/sve_context.h>
176 * The SVE architecture leaves space for future expansion of the
177 * vector length beyond its initial architectural limit of 2048 bits
180 * See linux/Documentation/arch/arm64/sve.rst for a description of the VL/VQ
183 #define SVE_VQ_BYTES __SVE_VQ_BYTES /* bytes per quadword */
185 #define SVE_VQ_MIN __SVE_VQ_MIN
186 #define SVE_VQ_MAX __SVE_VQ_MAX
188 #define SVE_VL_MIN __SVE_VL_MIN
189 #define SVE_VL_MAX __SVE_VL_MAX
191 #define SVE_NUM_ZREGS __SVE_NUM_ZREGS
192 #define SVE_NUM_PREGS __SVE_NUM_PREGS
194 #define sve_vl_valid(vl) __sve_vl_valid(vl)
195 #define sve_vq_from_vl(vl) __sve_vq_from_vl(vl)
196 #define sve_vl_from_vq(vq) __sve_vl_from_vq(vq)
199 * If the SVE registers are currently live for the thread at signal delivery,
200 * sve_context.head.size >=
201 * SVE_SIG_CONTEXT_SIZE(sve_vq_from_vl(sve_context.vl))
202 * and the register data may be accessed using the SVE_SIG_*() macros.
204 * If sve_context.head.size <
205 * SVE_SIG_CONTEXT_SIZE(sve_vq_from_vl(sve_context.vl)),
206 * the SVE registers were not live for the thread and no register data
207 * is included: in this case, the SVE_SIG_*() macros should not be
208 * used except for this check.
210 * The same convention applies when returning from a signal: a caller
211 * will need to remove or resize the sve_context block if it wants to
212 * make the SVE registers live when they were previously non-live or
213 * vice-versa. This may require the caller to allocate fresh
214 * memory and/or move other context blocks in the signal frame.
216 * Changing the vector length during signal return is not permitted:
217 * sve_context.vl must equal the thread's current vector length when
220 * On systems with support for SME the SVE register state may reflect either
221 * streaming or non-streaming mode. In streaming mode the streaming mode
222 * vector length will be used and the flag SVE_SIG_FLAG_SM will be set in
223 * the flags field. It is permitted to enter or leave streaming mode in
224 * a signal return, applications should take care to ensure that any difference
225 * in vector length between the two modes is handled, including any resizing
226 * and movement of context blocks.
228 * Note: for all these macros, the "vq" argument denotes the vector length
229 * in quadwords (i.e., units of 128 bits).
231 * The correct way to obtain vq is to use sve_vq_from_vl(vl). The
232 * result is valid if and only if sve_vl_valid(vl) is true. This is
233 * guaranteed for a struct sve_context written by the kernel.
236 * Additional macros describe the contents and layout of the payload.
237 * For each, SVE_SIG_x_OFFSET(args) is the start offset relative to
238 * the start of struct sve_context, and SVE_SIG_x_SIZE(args) is the
243 * REGS the entire SVE context
245 * ZREGS __uint128_t[SVE_NUM_ZREGS][vq] all Z-registers
246 * ZREG __uint128_t[vq] individual Z-register Zn
248 * PREGS uint16_t[SVE_NUM_PREGS][vq] all P-registers
249 * PREG uint16_t[vq] individual P-register Pn
251 * FFR uint16_t[vq] first-fault status register
253 * Additional data might be appended in the future.
255 * Unlike vregs[] in fpsimd_context, each SVE scalable register (Z-, P- or FFR)
256 * is encoded in memory in an endianness-invariant format, with the byte at
257 * offset i from the start of the in-memory representation containing bits
258 * [(7 + 8 * i) : (8 * i)] of the register value.
261 #define SVE_SIG_ZREG_SIZE(vq) __SVE_ZREG_SIZE(vq)
262 #define SVE_SIG_PREG_SIZE(vq) __SVE_PREG_SIZE(vq)
263 #define SVE_SIG_FFR_SIZE(vq) __SVE_FFR_SIZE(vq)
265 #define SVE_SIG_REGS_OFFSET \
266 ((sizeof(struct sve_context) + (__SVE_VQ_BYTES - 1)) \
267 / __SVE_VQ_BYTES * __SVE_VQ_BYTES)
269 #define SVE_SIG_ZREGS_OFFSET \
270 (SVE_SIG_REGS_OFFSET + __SVE_ZREGS_OFFSET)
271 #define SVE_SIG_ZREG_OFFSET(vq, n) \
272 (SVE_SIG_REGS_OFFSET + __SVE_ZREG_OFFSET(vq, n))
273 #define SVE_SIG_ZREGS_SIZE(vq) __SVE_ZREGS_SIZE(vq)
275 #define SVE_SIG_PREGS_OFFSET(vq) \
276 (SVE_SIG_REGS_OFFSET + __SVE_PREGS_OFFSET(vq))
277 #define SVE_SIG_PREG_OFFSET(vq, n) \
278 (SVE_SIG_REGS_OFFSET + __SVE_PREG_OFFSET(vq, n))
279 #define SVE_SIG_PREGS_SIZE(vq) __SVE_PREGS_SIZE(vq)
281 #define SVE_SIG_FFR_OFFSET(vq) \
282 (SVE_SIG_REGS_OFFSET + __SVE_FFR_OFFSET(vq))
284 #define SVE_SIG_REGS_SIZE(vq) \
285 (__SVE_FFR_OFFSET(vq) + __SVE_FFR_SIZE(vq))
287 #define SVE_SIG_CONTEXT_SIZE(vq) \
288 (SVE_SIG_REGS_OFFSET + SVE_SIG_REGS_SIZE(vq))
291 * If the ZA register is enabled for the thread at signal delivery then,
292 * za_context.head.size >= ZA_SIG_CONTEXT_SIZE(sve_vq_from_vl(za_context.vl))
293 * and the register data may be accessed using the ZA_SIG_*() macros.
295 * If za_context.head.size < ZA_SIG_CONTEXT_SIZE(sve_vq_from_vl(za_context.vl))
296 * then ZA was not enabled and no register data was included in which case
297 * ZA register was not enabled for the thread and no register data
298 * the ZA_SIG_*() macros should not be used except for this check.
300 * The same convention applies when returning from a signal: a caller
301 * will need to remove or resize the za_context block if it wants to
302 * enable the ZA register when it was previously non-live or vice-versa.
303 * This may require the caller to allocate fresh memory and/or move other
304 * context blocks in the signal frame.
306 * Changing the vector length during signal return is not permitted:
307 * za_context.vl must equal the thread's current SME vector length when
311 #define ZA_SIG_REGS_OFFSET \
312 ((sizeof(struct za_context) + (__SVE_VQ_BYTES - 1)) \
313 / __SVE_VQ_BYTES * __SVE_VQ_BYTES)
315 #define ZA_SIG_REGS_SIZE(vq) ((vq * __SVE_VQ_BYTES) * (vq * __SVE_VQ_BYTES))
317 #define ZA_SIG_ZAV_OFFSET(vq, n) (ZA_SIG_REGS_OFFSET + \
318 (SVE_SIG_ZREG_SIZE(vq) * n))
320 #define ZA_SIG_CONTEXT_SIZE(vq) \
321 (ZA_SIG_REGS_OFFSET + ZA_SIG_REGS_SIZE(vq))
323 #define ZT_SIG_REG_SIZE 512
325 #define ZT_SIG_REG_BYTES (ZT_SIG_REG_SIZE / 8)
327 #define ZT_SIG_REGS_OFFSET sizeof(struct zt_context)
329 #define ZT_SIG_REGS_SIZE(n) (ZT_SIG_REG_BYTES * n)
331 #define ZT_SIG_CONTEXT_SIZE(n) \
332 (sizeof(struct zt_context) + ZT_SIG_REGS_SIZE(n))
334 #endif /* _UAPI__ASM_SIGCONTEXT_H */