xref: /openbmc/linux/arch/arm64/include/asm/fpsimd.h (revision f71a261a)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2012 ARM Ltd.
4  */
5 #ifndef __ASM_FP_H
6 #define __ASM_FP_H
7 
8 #include <asm/errno.h>
9 #include <asm/ptrace.h>
10 #include <asm/processor.h>
11 #include <asm/sigcontext.h>
12 #include <asm/sysreg.h>
13 
14 #ifndef __ASSEMBLY__
15 
16 #include <linux/bitmap.h>
17 #include <linux/build_bug.h>
18 #include <linux/bug.h>
19 #include <linux/cache.h>
20 #include <linux/init.h>
21 #include <linux/stddef.h>
22 #include <linux/types.h>
23 
24 #ifdef CONFIG_COMPAT
25 /* Masks for extracting the FPSR and FPCR from the FPSCR */
26 #define VFP_FPSCR_STAT_MASK	0xf800009f
27 #define VFP_FPSCR_CTRL_MASK	0x07f79f00
28 /*
29  * The VFP state has 32x64-bit registers and a single 32-bit
30  * control/status register.
31  */
32 #define VFP_STATE_SIZE		((32 * 8) + 4)
33 #endif
34 
35 /*
36  * When we defined the maximum SVE vector length we defined the ABI so
37  * that the maximum vector length included all the reserved for future
38  * expansion bits in ZCR rather than those just currently defined by
39  * the architecture. While SME follows a similar pattern the fact that
40  * it includes a square matrix means that any allocations that attempt
41  * to cover the maximum potential vector length (such as happen with
42  * the regset used for ptrace) end up being extremely large. Define
43  * the much lower actual limit for use in such situations.
44  */
45 #define SME_VQ_MAX	16
46 
47 struct task_struct;
48 
49 extern void fpsimd_save_state(struct user_fpsimd_state *state);
50 extern void fpsimd_load_state(struct user_fpsimd_state *state);
51 
52 extern void fpsimd_thread_switch(struct task_struct *next);
53 extern void fpsimd_flush_thread(void);
54 
55 extern void fpsimd_signal_preserve_current_state(void);
56 extern void fpsimd_preserve_current_state(void);
57 extern void fpsimd_restore_current_state(void);
58 extern void fpsimd_update_current_state(struct user_fpsimd_state const *state);
59 
60 extern void fpsimd_bind_state_to_cpu(struct user_fpsimd_state *state,
61 				     void *sve_state, unsigned int sve_vl,
62 				     void *za_state, unsigned int sme_vl,
63 				     u64 *svcr);
64 
65 extern void fpsimd_flush_task_state(struct task_struct *target);
66 extern void fpsimd_save_and_flush_cpu_state(void);
67 
68 static inline bool thread_sm_enabled(struct thread_struct *thread)
69 {
70 	return system_supports_sme() && (thread->svcr & SVCR_SM_MASK);
71 }
72 
73 static inline bool thread_za_enabled(struct thread_struct *thread)
74 {
75 	return system_supports_sme() && (thread->svcr & SVCR_ZA_MASK);
76 }
77 
78 /* Maximum VL that SVE/SME VL-agnostic software can transparently support */
79 #define VL_ARCH_MAX 0x100
80 
81 /* Offset of FFR in the SVE register dump */
82 static inline size_t sve_ffr_offset(int vl)
83 {
84 	return SVE_SIG_FFR_OFFSET(sve_vq_from_vl(vl)) - SVE_SIG_REGS_OFFSET;
85 }
86 
87 static inline void *sve_pffr(struct thread_struct *thread)
88 {
89 	unsigned int vl;
90 
91 	if (system_supports_sme() && thread_sm_enabled(thread))
92 		vl = thread_get_sme_vl(thread);
93 	else
94 		vl = thread_get_sve_vl(thread);
95 
96 	return (char *)thread->sve_state + sve_ffr_offset(vl);
97 }
98 
99 extern void sve_save_state(void *state, u32 *pfpsr, int save_ffr);
100 extern void sve_load_state(void const *state, u32 const *pfpsr,
101 			   int restore_ffr);
102 extern void sve_flush_live(bool flush_ffr, unsigned long vq_minus_1);
103 extern unsigned int sve_get_vl(void);
104 extern void sve_set_vq(unsigned long vq_minus_1);
105 extern void sme_set_vq(unsigned long vq_minus_1);
106 extern void za_save_state(void *state);
107 extern void za_load_state(void const *state);
108 
109 struct arm64_cpu_capabilities;
110 extern void sve_kernel_enable(const struct arm64_cpu_capabilities *__unused);
111 extern void sme_kernel_enable(const struct arm64_cpu_capabilities *__unused);
112 extern void fa64_kernel_enable(const struct arm64_cpu_capabilities *__unused);
113 
114 extern u64 read_zcr_features(void);
115 extern u64 read_smcr_features(void);
116 
117 /*
118  * Helpers to translate bit indices in sve_vq_map to VQ values (and
119  * vice versa).  This allows find_next_bit() to be used to find the
120  * _maximum_ VQ not exceeding a certain value.
121  */
122 static inline unsigned int __vq_to_bit(unsigned int vq)
123 {
124 	return SVE_VQ_MAX - vq;
125 }
126 
127 static inline unsigned int __bit_to_vq(unsigned int bit)
128 {
129 	return SVE_VQ_MAX - bit;
130 }
131 
132 
133 struct vl_info {
134 	enum vec_type type;
135 	const char *name;		/* For display purposes */
136 
137 	/* Minimum supported vector length across all CPUs */
138 	int min_vl;
139 
140 	/* Maximum supported vector length across all CPUs */
141 	int max_vl;
142 	int max_virtualisable_vl;
143 
144 	/*
145 	 * Set of available vector lengths,
146 	 * where length vq encoded as bit __vq_to_bit(vq):
147 	 */
148 	DECLARE_BITMAP(vq_map, SVE_VQ_MAX);
149 
150 	/* Set of vector lengths present on at least one cpu: */
151 	DECLARE_BITMAP(vq_partial_map, SVE_VQ_MAX);
152 };
153 
154 #ifdef CONFIG_ARM64_SVE
155 
156 extern void sve_alloc(struct task_struct *task);
157 extern void fpsimd_release_task(struct task_struct *task);
158 extern void fpsimd_sync_to_sve(struct task_struct *task);
159 extern void fpsimd_force_sync_to_sve(struct task_struct *task);
160 extern void sve_sync_to_fpsimd(struct task_struct *task);
161 extern void sve_sync_from_fpsimd_zeropad(struct task_struct *task);
162 
163 extern int vec_set_vector_length(struct task_struct *task, enum vec_type type,
164 				 unsigned long vl, unsigned long flags);
165 
166 extern int sve_set_current_vl(unsigned long arg);
167 extern int sve_get_current_vl(void);
168 
169 static inline void sve_user_disable(void)
170 {
171 	sysreg_clear_set(cpacr_el1, CPACR_EL1_ZEN_EL0EN, 0);
172 }
173 
174 static inline void sve_user_enable(void)
175 {
176 	sysreg_clear_set(cpacr_el1, 0, CPACR_EL1_ZEN_EL0EN);
177 }
178 
179 #define sve_cond_update_zcr_vq(val, reg)		\
180 	do {						\
181 		u64 __zcr = read_sysreg_s((reg));	\
182 		u64 __new = __zcr & ~ZCR_ELx_LEN_MASK;	\
183 		__new |= (val) & ZCR_ELx_LEN_MASK;	\
184 		if (__zcr != __new)			\
185 			write_sysreg_s(__new, (reg));	\
186 	} while (0)
187 
188 /*
189  * Probing and setup functions.
190  * Calls to these functions must be serialised with one another.
191  */
192 enum vec_type;
193 
194 extern void __init vec_init_vq_map(enum vec_type type);
195 extern void vec_update_vq_map(enum vec_type type);
196 extern int vec_verify_vq_map(enum vec_type type);
197 extern void __init sve_setup(void);
198 
199 extern __ro_after_init struct vl_info vl_info[ARM64_VEC_MAX];
200 
201 static inline void write_vl(enum vec_type type, u64 val)
202 {
203 	u64 tmp;
204 
205 	switch (type) {
206 #ifdef CONFIG_ARM64_SVE
207 	case ARM64_VEC_SVE:
208 		tmp = read_sysreg_s(SYS_ZCR_EL1) & ~ZCR_ELx_LEN_MASK;
209 		write_sysreg_s(tmp | val, SYS_ZCR_EL1);
210 		break;
211 #endif
212 #ifdef CONFIG_ARM64_SME
213 	case ARM64_VEC_SME:
214 		tmp = read_sysreg_s(SYS_SMCR_EL1) & ~SMCR_ELx_LEN_MASK;
215 		write_sysreg_s(tmp | val, SYS_SMCR_EL1);
216 		break;
217 #endif
218 	default:
219 		WARN_ON_ONCE(1);
220 		break;
221 	}
222 }
223 
224 static inline int vec_max_vl(enum vec_type type)
225 {
226 	return vl_info[type].max_vl;
227 }
228 
229 static inline int vec_max_virtualisable_vl(enum vec_type type)
230 {
231 	return vl_info[type].max_virtualisable_vl;
232 }
233 
234 static inline int sve_max_vl(void)
235 {
236 	return vec_max_vl(ARM64_VEC_SVE);
237 }
238 
239 static inline int sve_max_virtualisable_vl(void)
240 {
241 	return vec_max_virtualisable_vl(ARM64_VEC_SVE);
242 }
243 
244 /* Ensure vq >= SVE_VQ_MIN && vq <= SVE_VQ_MAX before calling this function */
245 static inline bool vq_available(enum vec_type type, unsigned int vq)
246 {
247 	return test_bit(__vq_to_bit(vq), vl_info[type].vq_map);
248 }
249 
250 static inline bool sve_vq_available(unsigned int vq)
251 {
252 	return vq_available(ARM64_VEC_SVE, vq);
253 }
254 
255 size_t sve_state_size(struct task_struct const *task);
256 
257 #else /* ! CONFIG_ARM64_SVE */
258 
259 static inline void sve_alloc(struct task_struct *task) { }
260 static inline void fpsimd_release_task(struct task_struct *task) { }
261 static inline void sve_sync_to_fpsimd(struct task_struct *task) { }
262 static inline void sve_sync_from_fpsimd_zeropad(struct task_struct *task) { }
263 
264 static inline int sve_max_virtualisable_vl(void)
265 {
266 	return 0;
267 }
268 
269 static inline int sve_set_current_vl(unsigned long arg)
270 {
271 	return -EINVAL;
272 }
273 
274 static inline int sve_get_current_vl(void)
275 {
276 	return -EINVAL;
277 }
278 
279 static inline int sve_max_vl(void)
280 {
281 	return -EINVAL;
282 }
283 
284 static inline bool sve_vq_available(unsigned int vq) { return false; }
285 
286 static inline void sve_user_disable(void) { BUILD_BUG(); }
287 static inline void sve_user_enable(void) { BUILD_BUG(); }
288 
289 #define sve_cond_update_zcr_vq(val, reg) do { } while (0)
290 
291 static inline void vec_init_vq_map(enum vec_type t) { }
292 static inline void vec_update_vq_map(enum vec_type t) { }
293 static inline int vec_verify_vq_map(enum vec_type t) { return 0; }
294 static inline void sve_setup(void) { }
295 
296 static inline size_t sve_state_size(struct task_struct const *task)
297 {
298 	return 0;
299 }
300 
301 #endif /* ! CONFIG_ARM64_SVE */
302 
303 #ifdef CONFIG_ARM64_SME
304 
305 static inline void sme_user_disable(void)
306 {
307 	sysreg_clear_set(cpacr_el1, CPACR_EL1_SMEN_EL0EN, 0);
308 }
309 
310 static inline void sme_user_enable(void)
311 {
312 	sysreg_clear_set(cpacr_el1, 0, CPACR_EL1_SMEN_EL0EN);
313 }
314 
315 static inline void sme_smstart_sm(void)
316 {
317 	asm volatile(__msr_s(SYS_SVCR_SMSTART_SM_EL0, "xzr"));
318 }
319 
320 static inline void sme_smstop_sm(void)
321 {
322 	asm volatile(__msr_s(SYS_SVCR_SMSTOP_SM_EL0, "xzr"));
323 }
324 
325 static inline void sme_smstop(void)
326 {
327 	asm volatile(__msr_s(SYS_SVCR_SMSTOP_SMZA_EL0, "xzr"));
328 }
329 
330 extern void __init sme_setup(void);
331 
332 static inline int sme_max_vl(void)
333 {
334 	return vec_max_vl(ARM64_VEC_SME);
335 }
336 
337 static inline int sme_max_virtualisable_vl(void)
338 {
339 	return vec_max_virtualisable_vl(ARM64_VEC_SME);
340 }
341 
342 extern void sme_alloc(struct task_struct *task);
343 extern unsigned int sme_get_vl(void);
344 extern int sme_set_current_vl(unsigned long arg);
345 extern int sme_get_current_vl(void);
346 
347 /*
348  * Return how many bytes of memory are required to store the full SME
349  * specific state (currently just ZA) for task, given task's currently
350  * configured vector length.
351  */
352 static inline size_t za_state_size(struct task_struct const *task)
353 {
354 	unsigned int vl = task_get_sme_vl(task);
355 
356 	return ZA_SIG_REGS_SIZE(sve_vq_from_vl(vl));
357 }
358 
359 #else
360 
361 static inline void sme_user_disable(void) { BUILD_BUG(); }
362 static inline void sme_user_enable(void) { BUILD_BUG(); }
363 
364 static inline void sme_smstart_sm(void) { }
365 static inline void sme_smstop_sm(void) { }
366 static inline void sme_smstop(void) { }
367 
368 static inline void sme_alloc(struct task_struct *task) { }
369 static inline void sme_setup(void) { }
370 static inline unsigned int sme_get_vl(void) { return 0; }
371 static inline int sme_max_vl(void) { return 0; }
372 static inline int sme_max_virtualisable_vl(void) { return 0; }
373 static inline int sme_set_current_vl(unsigned long arg) { return -EINVAL; }
374 static inline int sme_get_current_vl(void) { return -EINVAL; }
375 
376 static inline size_t za_state_size(struct task_struct const *task)
377 {
378 	return 0;
379 }
380 
381 #endif /* ! CONFIG_ARM64_SME */
382 
383 /* For use by EFI runtime services calls only */
384 extern void __efi_fpsimd_begin(void);
385 extern void __efi_fpsimd_end(void);
386 
387 #endif
388 
389 #endif
390