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opuntiaOS - an operating system targeting x86 and ARMv7
1/*
2 * Copyright (C) 2020-2022 The opuntiaOS Project Authors.
3 * + Contributed by Nikita Melekhin <nimelehin@gmail.com>
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9#ifndef _KERNEL_DRIVERS_AARCH32_FPUV4_H
10#define _KERNEL_DRIVERS_AARCH32_FPUV4_H
11
12#include <drivers/driver_manager.h>
13#include <libkern/mask.h>
14#include <libkern/types.h>
15#include <platform/aarch32/interrupts.h>
16#include <platform/aarch32/registers.h>
17#include <platform/aarch32/target/cortex-a15/device_settings.h>
18
19#define FPU_STATE_ALIGNMENT (16)
20
21typedef struct {
22 uint64_t d[32];
23} __attribute__((aligned(FPU_STATE_ALIGNMENT))) fpu_state_t;
24
25void fpuv4_install();
26void fpu_init_state(fpu_state_t* new_fpu_state);
27extern uint32_t read_fpexc();
28extern void write_fpexc(uint32_t);
29extern void fpu_save(void*);
30extern void fpu_restore(void*);
31
32static inline void fpu_enable()
33{
34 write_fpexc(read_fpexc() | (1 << 30));
35}
36
37static inline void fpu_disable()
38{
39 write_fpexc(read_fpexc() & (~(1 << 30)));
40}
41
42static inline int fpu_is_avail()
43{
44 return (((read_cpacr() >> 20) & 0b1111) == 0b1111);
45}
46
47static inline void fpu_make_avail()
48{
49 write_cpacr(read_cpacr() | ((0b1111) << 20));
50}
51
52static inline void fpu_make_unavail()
53{
54 // Simply turn it off to make it unavailble.
55 uint32_t val = read_cpacr() & (~((0b1111) << 20));
56 write_cpacr(val | ((0b0101) << 20));
57}
58
59#endif //_KERNEL_DRIVERS_AARCH32_FPUV4_H