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 
psb_csync(void)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 
spe_init_el3(void)24 void spe_init_el3(void)
25 {
26 	uint64_t v;
27 
28 	/*
29 	 * MDCR_EL3.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.NSPBE: Profiling Buffer uses Non-secure Virtual Addresses.
34 	 * When FEAT_RME is not implemented, this field is RES0.
35 	 *
36 	 * MDCR_EL3.EnPMSN (ARM v8.7): Do not trap access to PMSNEVFR_EL1
37 	 * register at NS-EL1 or NS-EL2 to EL3 if FEAT_SPEv1p2 is implemented.
38 	 * Setting this bit to 1 doesn't have any effect on it when
39 	 * FEAT_SPEv1p2 not implemented.
40 	 */
41 	v = read_mdcr_el3();
42 	v |= MDCR_NSPB(MDCR_NSPB_EL1) | MDCR_EnPMSN_BIT;
43 	v &= ~(MDCR_NSPBE_BIT);
44 	write_mdcr_el3(v);
45 }
46 
spe_init_el2_unused(void)47 void spe_init_el2_unused(void)
48 {
49 	uint64_t v;
50 
51 	/*
52 	 * MDCR_EL2.TPMS (ARM v8.2): Do not trap statistical
53 	 * profiling controls to EL2.
54 	 *
55 	 * MDCR_EL2.E2PB (ARM v8.2): SPE enabled in Non-secure
56 	 * state. Accesses to profiling buffer controls at
57 	 * Non-secure EL1 are not trapped to EL2.
58 	 */
59 	v = read_mdcr_el2();
60 	v &= ~MDCR_EL2_TPMS;
61 	v |= MDCR_EL2_E2PB(MDCR_EL2_E2PB_EL1);
62 	write_mdcr_el2(v);
63 }
64 
spe_disable(void)65 void spe_disable(void)
66 {
67 	uint64_t v;
68 
69 	/* Drain buffered data */
70 	psb_csync();
71 	dsbnsh();
72 
73 	/* Disable profiling buffer */
74 	v = read_pmblimitr_el1();
75 	v &= ~(1ULL << 0);
76 	write_pmblimitr_el1(v);
77 	isb();
78 }
79 
spe_drain_buffers_hook(const void * arg)80 static void *spe_drain_buffers_hook(const void *arg)
81 {
82 	if (!is_feat_spe_supported())
83 		return (void *)-1;
84 
85 	/* Drain buffered data */
86 	psb_csync();
87 	dsbnsh();
88 
89 	return (void *)0;
90 }
91 
92 SUBSCRIBE_TO_EVENT(cm_entering_secure_world, spe_drain_buffers_hook);
93