1 /*
2 * Copyright (c) 2017-2023, ARM Limited and Contributors. All rights reserved.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
7 #include <stdbool.h>
8
9 #include <arch.h>
10 #include <arch_helpers.h>
11 #include <lib/cassert.h>
12 #include <lib/el3_runtime/pubsub.h>
13 #include <lib/extensions/sve.h>
14
15 CASSERT(SVE_VECTOR_LEN <= 2048, assert_sve_vl_too_long);
16 CASSERT(SVE_VECTOR_LEN >= 128, assert_sve_vl_too_short);
17 CASSERT((SVE_VECTOR_LEN % 128) == 0, assert_sve_vl_granule);
18
19 /*
20 * Converts SVE vector size restriction in bytes to LEN according to ZCR_EL3 documentation.
21 * VECTOR_SIZE = (LEN+1) * 128
22 */
23 #define CONVERT_SVE_LENGTH(x) (((x / 128) - 1))
24
sve_enable(cpu_context_t * context)25 void sve_enable(cpu_context_t *context)
26 {
27 u_register_t cptr_el3;
28
29 cptr_el3 = read_ctx_reg(get_el3state_ctx(context), CTX_CPTR_EL3);
30
31 /* Enable access to SVE functionality for all ELs. */
32 cptr_el3 = (cptr_el3 | CPTR_EZ_BIT) & ~(TFP_BIT);
33 write_ctx_reg(get_el3state_ctx(context), CTX_CPTR_EL3, cptr_el3);
34
35 /* Restrict maximum SVE vector length (SVE_VECTOR_LEN+1) * 128. */
36 write_ctx_reg(get_el3state_ctx(context), CTX_ZCR_EL3,
37 (ZCR_EL3_LEN_MASK & CONVERT_SVE_LENGTH(SVE_VECTOR_LEN)));
38 }
39
sve_disable(cpu_context_t * context)40 void sve_disable(cpu_context_t *context)
41 {
42 u_register_t reg;
43 el3_state_t *state;
44
45 /* Get the context state. */
46 state = get_el3state_ctx(context);
47
48 /* Disable SVE and FPU since they share registers. */
49 reg = read_ctx_reg(state, CTX_CPTR_EL3);
50 reg &= ~CPTR_EZ_BIT; /* Trap SVE */
51 reg |= TFP_BIT; /* Trap FPU/SIMD */
52 write_ctx_reg(state, CTX_CPTR_EL3, reg);
53 }
54
