xref: /aosp_15_r20/external/arm-trusted-firmware/lib/extensions/sve/sve.c (revision 54fd6939e177f8ff529b10183254802c76df6d08)
1*54fd6939SJiyong Park /*
2*54fd6939SJiyong Park  * Copyright (c) 2017-2021, ARM Limited and Contributors. All rights reserved.
3*54fd6939SJiyong Park  *
4*54fd6939SJiyong Park  * SPDX-License-Identifier: BSD-3-Clause
5*54fd6939SJiyong Park  */
6*54fd6939SJiyong Park 
7*54fd6939SJiyong Park #include <stdbool.h>
8*54fd6939SJiyong Park 
9*54fd6939SJiyong Park #include <arch.h>
10*54fd6939SJiyong Park #include <arch_helpers.h>
11*54fd6939SJiyong Park #include <lib/el3_runtime/pubsub.h>
12*54fd6939SJiyong Park #include <lib/extensions/sve.h>
13*54fd6939SJiyong Park 
14*54fd6939SJiyong Park /*
15*54fd6939SJiyong Park  * Converts SVE vector size restriction in bytes to LEN according to ZCR_EL3 documentation.
16*54fd6939SJiyong Park  * VECTOR_SIZE = (LEN+1) * 128
17*54fd6939SJiyong Park  */
18*54fd6939SJiyong Park #define CONVERT_SVE_LENGTH(x)	(((x / 128) - 1))
19*54fd6939SJiyong Park 
sve_supported(void)20*54fd6939SJiyong Park static bool sve_supported(void)
21*54fd6939SJiyong Park {
22*54fd6939SJiyong Park 	uint64_t features;
23*54fd6939SJiyong Park 
24*54fd6939SJiyong Park 	features = read_id_aa64pfr0_el1() >> ID_AA64PFR0_SVE_SHIFT;
25*54fd6939SJiyong Park 	return (features & ID_AA64PFR0_SVE_MASK) == 1U;
26*54fd6939SJiyong Park }
27*54fd6939SJiyong Park 
sve_enable(cpu_context_t * context)28*54fd6939SJiyong Park void sve_enable(cpu_context_t *context)
29*54fd6939SJiyong Park {
30*54fd6939SJiyong Park 	u_register_t cptr_el3;
31*54fd6939SJiyong Park 
32*54fd6939SJiyong Park 	if (!sve_supported()) {
33*54fd6939SJiyong Park 		return;
34*54fd6939SJiyong Park 	}
35*54fd6939SJiyong Park 
36*54fd6939SJiyong Park 	cptr_el3 = read_ctx_reg(get_el3state_ctx(context), CTX_CPTR_EL3);
37*54fd6939SJiyong Park 
38*54fd6939SJiyong Park 	/* Enable access to SVE functionality for all ELs. */
39*54fd6939SJiyong Park 	cptr_el3 = (cptr_el3 | CPTR_EZ_BIT) & ~(TFP_BIT);
40*54fd6939SJiyong Park 	write_ctx_reg(get_el3state_ctx(context), CTX_CPTR_EL3, cptr_el3);
41*54fd6939SJiyong Park 
42*54fd6939SJiyong Park 	/* Restrict maximum SVE vector length (SVE_VECTOR_LENGTH+1) * 128. */
43*54fd6939SJiyong Park 	write_ctx_reg(get_el3state_ctx(context), CTX_ZCR_EL3,
44*54fd6939SJiyong Park 		(ZCR_EL3_LEN_MASK & CONVERT_SVE_LENGTH(512)));
45*54fd6939SJiyong Park }
46*54fd6939SJiyong Park 
sve_disable(cpu_context_t * context)47*54fd6939SJiyong Park void sve_disable(cpu_context_t *context)
48*54fd6939SJiyong Park {
49*54fd6939SJiyong Park 	u_register_t reg;
50*54fd6939SJiyong Park 	el3_state_t *state;
51*54fd6939SJiyong Park 
52*54fd6939SJiyong Park 	/* Make sure SME is implemented in hardware before continuing. */
53*54fd6939SJiyong Park 	if (!sve_supported()) {
54*54fd6939SJiyong Park 		return;
55*54fd6939SJiyong Park 	}
56*54fd6939SJiyong Park 
57*54fd6939SJiyong Park 	/* Get the context state. */
58*54fd6939SJiyong Park 	state = get_el3state_ctx(context);
59*54fd6939SJiyong Park 
60*54fd6939SJiyong Park 	/* Disable SVE and FPU since they share registers. */
61*54fd6939SJiyong Park 	reg = read_ctx_reg(state, CTX_CPTR_EL3);
62*54fd6939SJiyong Park 	reg &= ~CPTR_EZ_BIT;	/* Trap SVE */
63*54fd6939SJiyong Park 	reg |= TFP_BIT;		/* Trap FPU/SIMD */
64*54fd6939SJiyong Park 	write_ctx_reg(state, CTX_CPTR_EL3, reg);
65*54fd6939SJiyong Park }
66