2 * Copyright (c) 2015 The FreeBSD Foundation
5 * This software was developed by Andrew Turner under
6 * sponsorship from the FreeBSD Foundation.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
40 #include <machine/armreg.h>
41 #include <machine/pcb.h>
42 #include <machine/vfp.h>
44 /* Sanity check we can store all the VFP registers */
45 CTASSERT(sizeof(((struct pcb *)0)->pcb_vfp) == 16 * 32);
52 cpacr = READ_SPECIALREG(cpacr_el1);
53 cpacr = (cpacr & ~CPACR_FPEN_MASK) | CPACR_FPEN_TRAP_NONE;
54 WRITE_SPECIALREG(cpacr_el1, cpacr);
63 cpacr = READ_SPECIALREG(cpacr_el1);
64 cpacr = (cpacr & ~CPACR_FPEN_MASK) | CPACR_FPEN_TRAP_ALL1;
65 WRITE_SPECIALREG(cpacr_el1, cpacr);
70 * Called when the thread is dying. If the thread was the last to use the
71 * VFP unit mark it as unused to tell the kernel the fp state is unowned.
72 * Ensure the VFP unit is off so we get an exception on the next access.
75 vfp_discard(struct thread *td)
78 if (PCPU_GET(fpcurthread) == td)
79 PCPU_SET(fpcurthread, NULL);
85 vfp_save_state(struct thread *td)
87 __int128_t *vfp_state;
93 * Only store the registers if the VFP is enabled,
94 * i.e. return if we are trapping on FP access.
96 cpacr = READ_SPECIALREG(cpacr_el1);
97 if ((cpacr & CPACR_FPEN_MASK) == CPACR_FPEN_TRAP_NONE) {
98 vfp_state = td->td_pcb->pcb_vfp;
102 "stp q0, q1, [%2, #16 * 0]\n"
103 "stp q2, q3, [%2, #16 * 2]\n"
104 "stp q4, q5, [%2, #16 * 4]\n"
105 "stp q6, q7, [%2, #16 * 6]\n"
106 "stp q8, q9, [%2, #16 * 8]\n"
107 "stp q10, q11, [%2, #16 * 10]\n"
108 "stp q12, q13, [%2, #16 * 12]\n"
109 "stp q14, q15, [%2, #16 * 14]\n"
110 "stp q16, q17, [%2, #16 * 16]\n"
111 "stp q18, q19, [%2, #16 * 18]\n"
112 "stp q20, q21, [%2, #16 * 20]\n"
113 "stp q22, q23, [%2, #16 * 22]\n"
114 "stp q24, q25, [%2, #16 * 24]\n"
115 "stp q26, q27, [%2, #16 * 26]\n"
116 "stp q28, q29, [%2, #16 * 28]\n"
117 "stp q30, q31, [%2, #16 * 30]\n"
118 : "=&r"(fpcr), "=&r"(fpsr) : "r"(vfp_state));
120 td->td_pcb->pcb_fpcr = fpcr;
121 td->td_pcb->pcb_fpsr = fpsr;
130 vfp_restore_state(void)
132 __int128_t *vfp_state;
139 cpu = PCPU_GET(cpuid);
140 curpcb = curthread->td_pcb;
141 curpcb->pcb_fpflags |= PCB_FP_STARTED;
145 if (PCPU_GET(fpcurthread) != curthread && cpu != curpcb->pcb_vfpcpu) {
147 vfp_state = curthread->td_pcb->pcb_vfp;
148 fpcr = curthread->td_pcb->pcb_fpcr;
149 fpsr = curthread->td_pcb->pcb_fpsr;
152 "ldp q0, q1, [%2, #16 * 0]\n"
153 "ldp q2, q3, [%2, #16 * 2]\n"
154 "ldp q4, q5, [%2, #16 * 4]\n"
155 "ldp q6, q7, [%2, #16 * 6]\n"
156 "ldp q8, q9, [%2, #16 * 8]\n"
157 "ldp q10, q11, [%2, #16 * 10]\n"
158 "ldp q12, q13, [%2, #16 * 12]\n"
159 "ldp q14, q15, [%2, #16 * 14]\n"
160 "ldp q16, q17, [%2, #16 * 16]\n"
161 "ldp q18, q19, [%2, #16 * 18]\n"
162 "ldp q20, q21, [%2, #16 * 20]\n"
163 "ldp q22, q23, [%2, #16 * 22]\n"
164 "ldp q24, q25, [%2, #16 * 24]\n"
165 "ldp q26, q27, [%2, #16 * 26]\n"
166 "ldp q28, q29, [%2, #16 * 28]\n"
167 "ldp q30, q31, [%2, #16 * 30]\n"
170 : : "r"(fpcr), "r"(fpsr), "r"(vfp_state));
172 PCPU_SET(fpcurthread, curthread);
173 curpcb->pcb_vfpcpu = cpu;
184 /* Check if there is a vfp unit present */
185 pfr = READ_SPECIALREG(id_aa64pfr0_el1);
186 if ((pfr & ID_AA64PFR0_FP_MASK) == ID_AA64PFR0_FP_NONE)
189 /* Disable to be enabled when it's used */
193 SYSINIT(vfp, SI_SUB_CPU, SI_ORDER_ANY, vfp_init, NULL);