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_features.h> 11 #include <arch_helpers.h> 12 #include <lib/el3_runtime/pubsub.h> 13 #include <lib/extensions/spe.h> 14 15 static inline void psb_csync(void) 16 { 17 /* 18 * The assembler does not yet understand the psb csync mnemonic 19 * so use the equivalent hint instruction. 20 */ 21 __asm__ volatile("hint #17"); 22 } 23 24 void spe_init_el3(void) 25 { 26 uint64_t v; 27 28 /* 29 * MDCR_EL2.NSPB (ARM v8.2): SPE enabled in Non-secure state 30 * and disabled in secure state. Accesses to SPE registers at 31 * S-EL1 generate trap exceptions to EL3. 32 * 33 * MDCR_EL3.EnPMSN (ARM v8.7): Do not trap access to PMSNEVFR_EL1 34 * register at NS-EL1 or NS-EL2 to EL3 if FEAT_SPEv1p2 is implemented. 35 * Setting this bit to 1 doesn't have any effect on it when 36 * FEAT_SPEv1p2 not implemented. 37 */ 38 v = read_mdcr_el3(); 39 v |= MDCR_NSPB(MDCR_NSPB_EL1) | MDCR_EnPMSN_BIT; 40 write_mdcr_el3(v); 41 } 42 43 void spe_init_el2_unused(void) 44 { 45 uint64_t v; 46 47 /* 48 * MDCR_EL2.TPMS (ARM v8.2): Do not trap statistical 49 * profiling controls to EL2. 50 * 51 * MDCR_EL2.E2PB (ARM v8.2): SPE enabled in Non-secure 52 * state. Accesses to profiling buffer controls at 53 * Non-secure EL1 are not trapped to EL2. 54 */ 55 v = read_mdcr_el2(); 56 v &= ~MDCR_EL2_TPMS; 57 v |= MDCR_EL2_E2PB(MDCR_EL2_E2PB_EL1); 58 write_mdcr_el2(v); 59 } 60 61 void spe_disable(void) 62 { 63 uint64_t v; 64 65 /* Drain buffered data */ 66 psb_csync(); 67 dsbnsh(); 68 69 /* Disable profiling buffer */ 70 v = read_pmblimitr_el1(); 71 v &= ~(1ULL << 0); 72 write_pmblimitr_el1(v); 73 isb(); 74 } 75 76 static void *spe_drain_buffers_hook(const void *arg) 77 { 78 if (!is_feat_spe_supported()) 79 return (void *)-1; 80 81 /* Drain buffered data */ 82 psb_csync(); 83 dsbnsh(); 84 85 return (void *)0; 86 } 87 88 SUBSCRIBE_TO_EVENT(cm_entering_secure_world, spe_drain_buffers_hook); 89