xref: /openbmc/linux/arch/arm64/include/asm/fpsimd.h (revision 8c018386)
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.  Using this length to allocate worst size buffers
40  * results in excessively large allocations, and this effect is even
41  * more pronounced for SME due to ZA.  Define more suitable VLs for
42  * these situations.
43  */
44 #define ARCH_SVE_VQ_MAX ((ZCR_ELx_LEN_MASK >> ZCR_ELx_LEN_SHIFT) + 1)
45 #define SME_VQ_MAX	((SMCR_ELx_LEN_MASK >> SMCR_ELx_LEN_SHIFT) + 1)
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 extern void fpsimd_kvm_prepare(void);
60 
61 struct cpu_fp_state {
62 	struct user_fpsimd_state *st;
63 	void *sve_state;
64 	void *sme_state;
65 	u64 *svcr;
66 	unsigned int sve_vl;
67 	unsigned int sme_vl;
68 	enum fp_type *fp_type;
69 	enum fp_type to_save;
70 };
71 
72 extern void fpsimd_bind_state_to_cpu(struct cpu_fp_state *fp_state);
73 
74 extern void fpsimd_flush_task_state(struct task_struct *target);
75 extern void fpsimd_save_and_flush_cpu_state(void);
76 
77 static inline bool thread_sm_enabled(struct thread_struct *thread)
78 {
79 	return system_supports_sme() && (thread->svcr & SVCR_SM_MASK);
80 }
81 
82 static inline bool thread_za_enabled(struct thread_struct *thread)
83 {
84 	return system_supports_sme() && (thread->svcr & SVCR_ZA_MASK);
85 }
86 
87 /* Maximum VL that SVE/SME VL-agnostic software can transparently support */
88 #define VL_ARCH_MAX 0x100
89 
90 /* Offset of FFR in the SVE register dump */
91 static inline size_t sve_ffr_offset(int vl)
92 {
93 	return SVE_SIG_FFR_OFFSET(sve_vq_from_vl(vl)) - SVE_SIG_REGS_OFFSET;
94 }
95 
96 static inline void *sve_pffr(struct thread_struct *thread)
97 {
98 	unsigned int vl;
99 
100 	if (system_supports_sme() && thread_sm_enabled(thread))
101 		vl = thread_get_sme_vl(thread);
102 	else
103 		vl = thread_get_sve_vl(thread);
104 
105 	return (char *)thread->sve_state + sve_ffr_offset(vl);
106 }
107 
108 static inline void *thread_zt_state(struct thread_struct *thread)
109 {
110 	/* The ZT register state is stored immediately after the ZA state */
111 	unsigned int sme_vq = sve_vq_from_vl(thread_get_sme_vl(thread));
112 	return thread->sme_state + ZA_SIG_REGS_SIZE(sme_vq);
113 }
114 
115 extern void sve_save_state(void *state, u32 *pfpsr, int save_ffr);
116 extern void sve_load_state(void const *state, u32 const *pfpsr,
117 			   int restore_ffr);
118 extern void sve_flush_live(bool flush_ffr, unsigned long vq_minus_1);
119 extern unsigned int sve_get_vl(void);
120 extern void sve_set_vq(unsigned long vq_minus_1);
121 extern void sme_set_vq(unsigned long vq_minus_1);
122 extern void sme_save_state(void *state, int zt);
123 extern void sme_load_state(void const *state, int zt);
124 
125 struct arm64_cpu_capabilities;
126 extern void sve_kernel_enable(const struct arm64_cpu_capabilities *__unused);
127 extern void sme_kernel_enable(const struct arm64_cpu_capabilities *__unused);
128 extern void sme2_kernel_enable(const struct arm64_cpu_capabilities *__unused);
129 extern void fa64_kernel_enable(const struct arm64_cpu_capabilities *__unused);
130 
131 extern u64 read_zcr_features(void);
132 extern u64 read_smcr_features(void);
133 
134 /*
135  * Helpers to translate bit indices in sve_vq_map to VQ values (and
136  * vice versa).  This allows find_next_bit() to be used to find the
137  * _maximum_ VQ not exceeding a certain value.
138  */
139 static inline unsigned int __vq_to_bit(unsigned int vq)
140 {
141 	return SVE_VQ_MAX - vq;
142 }
143 
144 static inline unsigned int __bit_to_vq(unsigned int bit)
145 {
146 	return SVE_VQ_MAX - bit;
147 }
148 
149 
150 struct vl_info {
151 	enum vec_type type;
152 	const char *name;		/* For display purposes */
153 
154 	/* Minimum supported vector length across all CPUs */
155 	int min_vl;
156 
157 	/* Maximum supported vector length across all CPUs */
158 	int max_vl;
159 	int max_virtualisable_vl;
160 
161 	/*
162 	 * Set of available vector lengths,
163 	 * where length vq encoded as bit __vq_to_bit(vq):
164 	 */
165 	DECLARE_BITMAP(vq_map, SVE_VQ_MAX);
166 
167 	/* Set of vector lengths present on at least one cpu: */
168 	DECLARE_BITMAP(vq_partial_map, SVE_VQ_MAX);
169 };
170 
171 #ifdef CONFIG_ARM64_SVE
172 
173 extern void sve_alloc(struct task_struct *task, bool flush);
174 extern void fpsimd_release_task(struct task_struct *task);
175 extern void fpsimd_sync_to_sve(struct task_struct *task);
176 extern void fpsimd_force_sync_to_sve(struct task_struct *task);
177 extern void sve_sync_to_fpsimd(struct task_struct *task);
178 extern void sve_sync_from_fpsimd_zeropad(struct task_struct *task);
179 
180 extern int vec_set_vector_length(struct task_struct *task, enum vec_type type,
181 				 unsigned long vl, unsigned long flags);
182 
183 extern int sve_set_current_vl(unsigned long arg);
184 extern int sve_get_current_vl(void);
185 
186 static inline void sve_user_disable(void)
187 {
188 	sysreg_clear_set(cpacr_el1, CPACR_EL1_ZEN_EL0EN, 0);
189 }
190 
191 static inline void sve_user_enable(void)
192 {
193 	sysreg_clear_set(cpacr_el1, 0, CPACR_EL1_ZEN_EL0EN);
194 }
195 
196 #define sve_cond_update_zcr_vq(val, reg)		\
197 	do {						\
198 		u64 __zcr = read_sysreg_s((reg));	\
199 		u64 __new = __zcr & ~ZCR_ELx_LEN_MASK;	\
200 		__new |= (val) & ZCR_ELx_LEN_MASK;	\
201 		if (__zcr != __new)			\
202 			write_sysreg_s(__new, (reg));	\
203 	} while (0)
204 
205 /*
206  * Probing and setup functions.
207  * Calls to these functions must be serialised with one another.
208  */
209 enum vec_type;
210 
211 extern void __init vec_init_vq_map(enum vec_type type);
212 extern void vec_update_vq_map(enum vec_type type);
213 extern int vec_verify_vq_map(enum vec_type type);
214 extern void __init sve_setup(void);
215 
216 extern __ro_after_init struct vl_info vl_info[ARM64_VEC_MAX];
217 
218 static inline void write_vl(enum vec_type type, u64 val)
219 {
220 	u64 tmp;
221 
222 	switch (type) {
223 #ifdef CONFIG_ARM64_SVE
224 	case ARM64_VEC_SVE:
225 		tmp = read_sysreg_s(SYS_ZCR_EL1) & ~ZCR_ELx_LEN_MASK;
226 		write_sysreg_s(tmp | val, SYS_ZCR_EL1);
227 		break;
228 #endif
229 #ifdef CONFIG_ARM64_SME
230 	case ARM64_VEC_SME:
231 		tmp = read_sysreg_s(SYS_SMCR_EL1) & ~SMCR_ELx_LEN_MASK;
232 		write_sysreg_s(tmp | val, SYS_SMCR_EL1);
233 		break;
234 #endif
235 	default:
236 		WARN_ON_ONCE(1);
237 		break;
238 	}
239 }
240 
241 static inline int vec_max_vl(enum vec_type type)
242 {
243 	return vl_info[type].max_vl;
244 }
245 
246 static inline int vec_max_virtualisable_vl(enum vec_type type)
247 {
248 	return vl_info[type].max_virtualisable_vl;
249 }
250 
251 static inline int sve_max_vl(void)
252 {
253 	return vec_max_vl(ARM64_VEC_SVE);
254 }
255 
256 static inline int sve_max_virtualisable_vl(void)
257 {
258 	return vec_max_virtualisable_vl(ARM64_VEC_SVE);
259 }
260 
261 /* Ensure vq >= SVE_VQ_MIN && vq <= SVE_VQ_MAX before calling this function */
262 static inline bool vq_available(enum vec_type type, unsigned int vq)
263 {
264 	return test_bit(__vq_to_bit(vq), vl_info[type].vq_map);
265 }
266 
267 static inline bool sve_vq_available(unsigned int vq)
268 {
269 	return vq_available(ARM64_VEC_SVE, vq);
270 }
271 
272 size_t sve_state_size(struct task_struct const *task);
273 
274 #else /* ! CONFIG_ARM64_SVE */
275 
276 static inline void sve_alloc(struct task_struct *task, bool flush) { }
277 static inline void fpsimd_release_task(struct task_struct *task) { }
278 static inline void sve_sync_to_fpsimd(struct task_struct *task) { }
279 static inline void sve_sync_from_fpsimd_zeropad(struct task_struct *task) { }
280 
281 static inline int sve_max_virtualisable_vl(void)
282 {
283 	return 0;
284 }
285 
286 static inline int sve_set_current_vl(unsigned long arg)
287 {
288 	return -EINVAL;
289 }
290 
291 static inline int sve_get_current_vl(void)
292 {
293 	return -EINVAL;
294 }
295 
296 static inline int sve_max_vl(void)
297 {
298 	return -EINVAL;
299 }
300 
301 static inline bool sve_vq_available(unsigned int vq) { return false; }
302 
303 static inline void sve_user_disable(void) { BUILD_BUG(); }
304 static inline void sve_user_enable(void) { BUILD_BUG(); }
305 
306 #define sve_cond_update_zcr_vq(val, reg) do { } while (0)
307 
308 static inline void vec_init_vq_map(enum vec_type t) { }
309 static inline void vec_update_vq_map(enum vec_type t) { }
310 static inline int vec_verify_vq_map(enum vec_type t) { return 0; }
311 static inline void sve_setup(void) { }
312 
313 static inline size_t sve_state_size(struct task_struct const *task)
314 {
315 	return 0;
316 }
317 
318 #endif /* ! CONFIG_ARM64_SVE */
319 
320 #ifdef CONFIG_ARM64_SME
321 
322 static inline void sme_user_disable(void)
323 {
324 	sysreg_clear_set(cpacr_el1, CPACR_EL1_SMEN_EL0EN, 0);
325 }
326 
327 static inline void sme_user_enable(void)
328 {
329 	sysreg_clear_set(cpacr_el1, 0, CPACR_EL1_SMEN_EL0EN);
330 }
331 
332 static inline void sme_smstart_sm(void)
333 {
334 	asm volatile(__msr_s(SYS_SVCR_SMSTART_SM_EL0, "xzr"));
335 }
336 
337 static inline void sme_smstop_sm(void)
338 {
339 	asm volatile(__msr_s(SYS_SVCR_SMSTOP_SM_EL0, "xzr"));
340 }
341 
342 static inline void sme_smstop(void)
343 {
344 	asm volatile(__msr_s(SYS_SVCR_SMSTOP_SMZA_EL0, "xzr"));
345 }
346 
347 extern void __init sme_setup(void);
348 
349 static inline int sme_max_vl(void)
350 {
351 	return vec_max_vl(ARM64_VEC_SME);
352 }
353 
354 static inline int sme_max_virtualisable_vl(void)
355 {
356 	return vec_max_virtualisable_vl(ARM64_VEC_SME);
357 }
358 
359 extern void sme_alloc(struct task_struct *task, bool flush);
360 extern unsigned int sme_get_vl(void);
361 extern int sme_set_current_vl(unsigned long arg);
362 extern int sme_get_current_vl(void);
363 extern void sme_suspend_exit(void);
364 
365 /*
366  * Return how many bytes of memory are required to store the full SME
367  * specific state for task, given task's currently configured vector
368  * length.
369  */
370 static inline size_t sme_state_size(struct task_struct const *task)
371 {
372 	unsigned int vl = task_get_sme_vl(task);
373 	size_t size;
374 
375 	size = ZA_SIG_REGS_SIZE(sve_vq_from_vl(vl));
376 
377 	if (system_supports_sme2())
378 		size += ZT_SIG_REG_SIZE;
379 
380 	return size;
381 }
382 
383 #else
384 
385 static inline void sme_user_disable(void) { BUILD_BUG(); }
386 static inline void sme_user_enable(void) { BUILD_BUG(); }
387 
388 static inline void sme_smstart_sm(void) { }
389 static inline void sme_smstop_sm(void) { }
390 static inline void sme_smstop(void) { }
391 
392 static inline void sme_alloc(struct task_struct *task, bool flush) { }
393 static inline void sme_setup(void) { }
394 static inline unsigned int sme_get_vl(void) { return 0; }
395 static inline int sme_max_vl(void) { return 0; }
396 static inline int sme_max_virtualisable_vl(void) { return 0; }
397 static inline int sme_set_current_vl(unsigned long arg) { return -EINVAL; }
398 static inline int sme_get_current_vl(void) { return -EINVAL; }
399 static inline void sme_suspend_exit(void) { }
400 
401 static inline size_t sme_state_size(struct task_struct const *task)
402 {
403 	return 0;
404 }
405 
406 #endif /* ! CONFIG_ARM64_SME */
407 
408 /* For use by EFI runtime services calls only */
409 extern void __efi_fpsimd_begin(void);
410 extern void __efi_fpsimd_end(void);
411 
412 #endif
413 
414 #endif
415