1 /* 2 * Copyright (c) 2017-2021, 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/el3_runtime/pubsub.h> 12 #include <lib/extensions/sve.h> 13 14 /* 15 * Converts SVE vector size restriction in bytes to LEN according to ZCR_EL3 documentation. 16 * VECTOR_SIZE = (LEN+1) * 128 17 */ 18 #define CONVERT_SVE_LENGTH(x) (((x / 128) - 1)) 19 20 static bool sve_supported(void) 21 { 22 uint64_t features; 23 24 features = read_id_aa64pfr0_el1() >> ID_AA64PFR0_SVE_SHIFT; 25 return (features & ID_AA64PFR0_SVE_MASK) == 1U; 26 } 27 28 void sve_enable(cpu_context_t *context) 29 { 30 if (!sve_supported()) { 31 return; 32 } 33 34 u_register_t cptr_el3 = read_cptr_el3(); 35 36 /* Enable access to SVE functionality for all ELs. */ 37 cptr_el3 = (cptr_el3 | CPTR_EZ_BIT) & ~(TFP_BIT); 38 write_ctx_reg(get_el3state_ctx(context), CTX_CPTR_EL3, cptr_el3); 39 40 /* Restrict maximum SVE vector length (SVE_VECTOR_LENGTH+1) * 128. */ 41 write_ctx_reg(get_el3state_ctx(context), CTX_ZCR_EL3, 42 (ZCR_EL3_LEN_MASK & CONVERT_SVE_LENGTH(512))); 43 } 44