1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 /*
3 * Copyright (C) 2012 ARM Ltd.
4 *
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.
8 *
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.
13 *
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/>.
16 */
17 #ifndef _UAPI__ASM_SIGCONTEXT_H
18 #define _UAPI__ASM_SIGCONTEXT_H
19
20 #ifndef __ASSEMBLY__
21
22 #include <linux/types.h>
23
24 /*
25 * Signal context structure - contains all info to do with the state
26 * before the signal handler was invoked.
27 */
28 struct sigcontext {
29 __u64 fault_address;
30 /* AArch64 registers */
31 __u64 regs[31];
32 __u64 sp;
33 __u64 pc;
34 __u64 pstate;
35 /* 4K reserved for FP/SIMD state and future expansion */
36 __u8 __reserved[4096] __attribute__((__aligned__(16)));
37 };
38
39 /*
40 * Allocation of __reserved[]:
41 * (Note: records do not necessarily occur in the order shown here.)
42 *
43 * size description
44 *
45 * 0x210 fpsimd_context
46 * 0x10 esr_context
47 * 0x8a0 sve_context (vl <= 64) (optional)
48 * 0x20 extra_context (optional)
49 * 0x10 terminator (null _aarch64_ctx)
50 *
51 * 0x510 (reserved for future allocation)
52 *
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.
58 */
59
60 /*
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.
65 *
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.
69 */
70 struct _aarch64_ctx {
71 __u32 magic;
72 __u32 size;
73 };
74
75 #define FPSIMD_MAGIC 0x46508001
76
77 struct fpsimd_context {
78 struct _aarch64_ctx head;
79 __u32 fpsr;
80 __u32 fpcr;
81 __uint128_t vregs[32];
82 };
83
84 /*
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
88 *
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.
91 */
92
93 /* ESR_EL1 context */
94 #define ESR_MAGIC 0x45535201
95
96 struct esr_context {
97 struct _aarch64_ctx head;
98 __u64 esr;
99 };
100
101 /*
102 * extra_context: describes extra space in the signal frame for
103 * additional structures that don't fit in sigcontext.__reserved[].
104 *
105 * Note:
106 *
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
111 * this file.
112 *
113 * 2) There must not be more than one extra_context.
114 *
115 * 3) If extra_context is present, it must be followed immediately in
116 * sigcontext.__reserved[] by the terminating null _aarch64_ctx.
117 *
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.
123 *
124 * 5) The extra space must itself be terminated with a null
125 * _aarch64_ctx.
126 */
127 #define EXTRA_MAGIC 0x45585401
128
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 */
133 __u32 __reserved[3];
134 };
135
136 #define SVE_MAGIC 0x53564501
137
138 struct sve_context {
139 struct _aarch64_ctx head;
140 __u16 vl;
141 __u16 flags;
142 __u16 __reserved[2];
143 };
144
145 #define SVE_SIG_FLAG_SM 0x1 /* Context describes streaming mode */
146
147 /* TPIDR2_EL0 context */
148 #define TPIDR2_MAGIC 0x54504902
149
150 struct tpidr2_context {
151 struct _aarch64_ctx head;
152 __u64 tpidr2;
153 };
154
155 /* FPMR context */
156 #define FPMR_MAGIC 0x46504d52
157
158 struct fpmr_context {
159 struct _aarch64_ctx head;
160 __u64 fpmr;
161 };
162
163 #define ZA_MAGIC 0x54366345
164
165 struct za_context {
166 struct _aarch64_ctx head;
167 __u16 vl;
168 __u16 __reserved[3];
169 };
170
171 #define ZT_MAGIC 0x5a544e01
172
173 struct zt_context {
174 struct _aarch64_ctx head;
175 __u16 nregs;
176 __u16 __reserved[3];
177 };
178
179 #endif /* !__ASSEMBLY__ */
180
181 #include <asm/sve_context.h>
182
183 /*
184 * The SVE architecture leaves space for future expansion of the
185 * vector length beyond its initial architectural limit of 2048 bits
186 * (16 quadwords).
187 *
188 * See linux/Documentation/arch/arm64/sve.rst for a description of the VL/VQ
189 * terminology.
190 */
191 #define SVE_VQ_BYTES __SVE_VQ_BYTES /* bytes per quadword */
192
193 #define SVE_VQ_MIN __SVE_VQ_MIN
194 #define SVE_VQ_MAX __SVE_VQ_MAX
195
196 #define SVE_VL_MIN __SVE_VL_MIN
197 #define SVE_VL_MAX __SVE_VL_MAX
198
199 #define SVE_NUM_ZREGS __SVE_NUM_ZREGS
200 #define SVE_NUM_PREGS __SVE_NUM_PREGS
201
202 #define sve_vl_valid(vl) __sve_vl_valid(vl)
203 #define sve_vq_from_vl(vl) __sve_vq_from_vl(vl)
204 #define sve_vl_from_vq(vq) __sve_vl_from_vq(vq)
205
206 /*
207 * If the SVE registers are currently live for the thread at signal delivery,
208 * sve_context.head.size >=
209 * SVE_SIG_CONTEXT_SIZE(sve_vq_from_vl(sve_context.vl))
210 * and the register data may be accessed using the SVE_SIG_*() macros.
211 *
212 * If sve_context.head.size <
213 * SVE_SIG_CONTEXT_SIZE(sve_vq_from_vl(sve_context.vl)),
214 * the SVE registers were not live for the thread and no register data
215 * is included: in this case, the SVE_SIG_*() macros should not be
216 * used except for this check.
217 *
218 * The same convention applies when returning from a signal: a caller
219 * will need to remove or resize the sve_context block if it wants to
220 * make the SVE registers live when they were previously non-live or
221 * vice-versa. This may require the caller to allocate fresh
222 * memory and/or move other context blocks in the signal frame.
223 *
224 * Changing the vector length during signal return is not permitted:
225 * sve_context.vl must equal the thread's current vector length when
226 * doing a sigreturn.
227 *
228 * On systems with support for SME the SVE register state may reflect either
229 * streaming or non-streaming mode. In streaming mode the streaming mode
230 * vector length will be used and the flag SVE_SIG_FLAG_SM will be set in
231 * the flags field. It is permitted to enter or leave streaming mode in
232 * a signal return, applications should take care to ensure that any difference
233 * in vector length between the two modes is handled, including any resizing
234 * and movement of context blocks.
235 *
236 * Note: for all these macros, the "vq" argument denotes the vector length
237 * in quadwords (i.e., units of 128 bits).
238 *
239 * The correct way to obtain vq is to use sve_vq_from_vl(vl). The
240 * result is valid if and only if sve_vl_valid(vl) is true. This is
241 * guaranteed for a struct sve_context written by the kernel.
242 *
243 *
244 * Additional macros describe the contents and layout of the payload.
245 * For each, SVE_SIG_x_OFFSET(args) is the start offset relative to
246 * the start of struct sve_context, and SVE_SIG_x_SIZE(args) is the
247 * size in bytes:
248 *
249 * x type description
250 * - ---- -----------
251 * REGS the entire SVE context
252 *
253 * ZREGS __uint128_t[SVE_NUM_ZREGS][vq] all Z-registers
254 * ZREG __uint128_t[vq] individual Z-register Zn
255 *
256 * PREGS uint16_t[SVE_NUM_PREGS][vq] all P-registers
257 * PREG uint16_t[vq] individual P-register Pn
258 *
259 * FFR uint16_t[vq] first-fault status register
260 *
261 * Additional data might be appended in the future.
262 *
263 * Unlike vregs[] in fpsimd_context, each SVE scalable register (Z-, P- or FFR)
264 * is encoded in memory in an endianness-invariant format, with the byte at
265 * offset i from the start of the in-memory representation containing bits
266 * [(7 + 8 * i) : (8 * i)] of the register value.
267 */
268
269 #define SVE_SIG_ZREG_SIZE(vq) __SVE_ZREG_SIZE(vq)
270 #define SVE_SIG_PREG_SIZE(vq) __SVE_PREG_SIZE(vq)
271 #define SVE_SIG_FFR_SIZE(vq) __SVE_FFR_SIZE(vq)
272
273 #define SVE_SIG_REGS_OFFSET \
274 ((sizeof(struct sve_context) + (__SVE_VQ_BYTES - 1)) \
275 / __SVE_VQ_BYTES * __SVE_VQ_BYTES)
276
277 #define SVE_SIG_ZREGS_OFFSET \
278 (SVE_SIG_REGS_OFFSET + __SVE_ZREGS_OFFSET)
279 #define SVE_SIG_ZREG_OFFSET(vq, n) \
280 (SVE_SIG_REGS_OFFSET + __SVE_ZREG_OFFSET(vq, n))
281 #define SVE_SIG_ZREGS_SIZE(vq) __SVE_ZREGS_SIZE(vq)
282
283 #define SVE_SIG_PREGS_OFFSET(vq) \
284 (SVE_SIG_REGS_OFFSET + __SVE_PREGS_OFFSET(vq))
285 #define SVE_SIG_PREG_OFFSET(vq, n) \
286 (SVE_SIG_REGS_OFFSET + __SVE_PREG_OFFSET(vq, n))
287 #define SVE_SIG_PREGS_SIZE(vq) __SVE_PREGS_SIZE(vq)
288
289 #define SVE_SIG_FFR_OFFSET(vq) \
290 (SVE_SIG_REGS_OFFSET + __SVE_FFR_OFFSET(vq))
291
292 #define SVE_SIG_REGS_SIZE(vq) \
293 (__SVE_FFR_OFFSET(vq) + __SVE_FFR_SIZE(vq))
294
295 #define SVE_SIG_CONTEXT_SIZE(vq) \
296 (SVE_SIG_REGS_OFFSET + SVE_SIG_REGS_SIZE(vq))
297
298 /*
299 * If the ZA register is enabled for the thread at signal delivery then,
300 * za_context.head.size >= ZA_SIG_CONTEXT_SIZE(sve_vq_from_vl(za_context.vl))
301 * and the register data may be accessed using the ZA_SIG_*() macros.
302 *
303 * If za_context.head.size < ZA_SIG_CONTEXT_SIZE(sve_vq_from_vl(za_context.vl))
304 * then ZA was not enabled and no register data was included in which case
305 * ZA register was not enabled for the thread and no register data
306 * the ZA_SIG_*() macros should not be used except for this check.
307 *
308 * The same convention applies when returning from a signal: a caller
309 * will need to remove or resize the za_context block if it wants to
310 * enable the ZA register when it was previously non-live or vice-versa.
311 * This may require the caller to allocate fresh memory and/or move other
312 * context blocks in the signal frame.
313 *
314 * Changing the vector length during signal return is not permitted:
315 * za_context.vl must equal the thread's current SME vector length when
316 * doing a sigreturn.
317 */
318
319 #define ZA_SIG_REGS_OFFSET \
320 ((sizeof(struct za_context) + (__SVE_VQ_BYTES - 1)) \
321 / __SVE_VQ_BYTES * __SVE_VQ_BYTES)
322
323 #define ZA_SIG_REGS_SIZE(vq) (((vq) * __SVE_VQ_BYTES) * ((vq) * __SVE_VQ_BYTES))
324
325 #define ZA_SIG_ZAV_OFFSET(vq, n) (ZA_SIG_REGS_OFFSET + \
326 (SVE_SIG_ZREG_SIZE(vq) * (n)))
327
328 #define ZA_SIG_CONTEXT_SIZE(vq) \
329 (ZA_SIG_REGS_OFFSET + ZA_SIG_REGS_SIZE(vq))
330
331 #define ZT_SIG_REG_SIZE 512
332
333 #define ZT_SIG_REG_BYTES (ZT_SIG_REG_SIZE / 8)
334
335 #define ZT_SIG_REGS_OFFSET sizeof(struct zt_context)
336
337 #define ZT_SIG_REGS_SIZE(n) (ZT_SIG_REG_BYTES * (n))
338
339 #define ZT_SIG_CONTEXT_SIZE(n) \
340 (sizeof(struct zt_context) + ZT_SIG_REGS_SIZE(n))
341
342 #endif /* _UAPI__ASM_SIGCONTEXT_H */
343
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