1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2021 Western Digital Corporation or its affiliates.
4 *
5 * Authors:
6 *     Atish Patra <atish.patra@wdc.com>
7 *     Anup Patel <anup.patel@wdc.com>
8 */
9
10#include <linux/errno.h>
11#include <linux/err.h>
12#include <linux/kvm_host.h>
13#include <linux/uaccess.h>
14#include <asm/cpufeature.h>
15
16#ifdef CONFIG_FPU
17void kvm_riscv_vcpu_fp_reset(struct kvm_vcpu *vcpu)
18{
19	struct kvm_cpu_context *cntx = &vcpu->arch.guest_context;
20
21	cntx->sstatus &= ~SR_FS;
22	if (riscv_isa_extension_available(vcpu->arch.isa, f) ||
23	    riscv_isa_extension_available(vcpu->arch.isa, d))
24		cntx->sstatus |= SR_FS_INITIAL;
25	else
26		cntx->sstatus |= SR_FS_OFF;
27}
28
29static void kvm_riscv_vcpu_fp_clean(struct kvm_cpu_context *cntx)
30{
31	cntx->sstatus &= ~SR_FS;
32	cntx->sstatus |= SR_FS_CLEAN;
33}
34
35void kvm_riscv_vcpu_guest_fp_save(struct kvm_cpu_context *cntx,
36				  const unsigned long *isa)
37{
38	if ((cntx->sstatus & SR_FS) == SR_FS_DIRTY) {
39		if (riscv_isa_extension_available(isa, d))
40			__kvm_riscv_fp_d_save(cntx);
41		else if (riscv_isa_extension_available(isa, f))
42			__kvm_riscv_fp_f_save(cntx);
43		kvm_riscv_vcpu_fp_clean(cntx);
44	}
45}
46
47void kvm_riscv_vcpu_guest_fp_restore(struct kvm_cpu_context *cntx,
48				     const unsigned long *isa)
49{
50	if ((cntx->sstatus & SR_FS) != SR_FS_OFF) {
51		if (riscv_isa_extension_available(isa, d))
52			__kvm_riscv_fp_d_restore(cntx);
53		else if (riscv_isa_extension_available(isa, f))
54			__kvm_riscv_fp_f_restore(cntx);
55		kvm_riscv_vcpu_fp_clean(cntx);
56	}
57}
58
59void kvm_riscv_vcpu_host_fp_save(struct kvm_cpu_context *cntx)
60{
61	/* No need to check host sstatus as it can be modified outside */
62	if (riscv_isa_extension_available(NULL, d))
63		__kvm_riscv_fp_d_save(cntx);
64	else if (riscv_isa_extension_available(NULL, f))
65		__kvm_riscv_fp_f_save(cntx);
66}
67
68void kvm_riscv_vcpu_host_fp_restore(struct kvm_cpu_context *cntx)
69{
70	if (riscv_isa_extension_available(NULL, d))
71		__kvm_riscv_fp_d_restore(cntx);
72	else if (riscv_isa_extension_available(NULL, f))
73		__kvm_riscv_fp_f_restore(cntx);
74}
75#endif
76
77int kvm_riscv_vcpu_get_reg_fp(struct kvm_vcpu *vcpu,
78			      const struct kvm_one_reg *reg,
79			      unsigned long rtype)
80{
81	struct kvm_cpu_context *cntx = &vcpu->arch.guest_context;
82	unsigned long __user *uaddr =
83			(unsigned long __user *)(unsigned long)reg->addr;
84	unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
85					    KVM_REG_SIZE_MASK |
86					    rtype);
87	void *reg_val;
88
89	if ((rtype == KVM_REG_RISCV_FP_F) &&
90	    riscv_isa_extension_available(vcpu->arch.isa, f)) {
91		if (KVM_REG_SIZE(reg->id) != sizeof(u32))
92			return -EINVAL;
93		if (reg_num == KVM_REG_RISCV_FP_F_REG(fcsr))
94			reg_val = &cntx->fp.f.fcsr;
95		else if ((KVM_REG_RISCV_FP_F_REG(f[0]) <= reg_num) &&
96			  reg_num <= KVM_REG_RISCV_FP_F_REG(f[31]))
97			reg_val = &cntx->fp.f.f[reg_num];
98		else
99			return -ENOENT;
100	} else if ((rtype == KVM_REG_RISCV_FP_D) &&
101		   riscv_isa_extension_available(vcpu->arch.isa, d)) {
102		if (reg_num == KVM_REG_RISCV_FP_D_REG(fcsr)) {
103			if (KVM_REG_SIZE(reg->id) != sizeof(u32))
104				return -EINVAL;
105			reg_val = &cntx->fp.d.fcsr;
106		} else if ((KVM_REG_RISCV_FP_D_REG(f[0]) <= reg_num) &&
107			   reg_num <= KVM_REG_RISCV_FP_D_REG(f[31])) {
108			if (KVM_REG_SIZE(reg->id) != sizeof(u64))
109				return -EINVAL;
110			reg_val = &cntx->fp.d.f[reg_num];
111		} else
112			return -ENOENT;
113	} else
114		return -ENOENT;
115
116	if (copy_to_user(uaddr, reg_val, KVM_REG_SIZE(reg->id)))
117		return -EFAULT;
118
119	return 0;
120}
121
122int kvm_riscv_vcpu_set_reg_fp(struct kvm_vcpu *vcpu,
123			      const struct kvm_one_reg *reg,
124			      unsigned long rtype)
125{
126	struct kvm_cpu_context *cntx = &vcpu->arch.guest_context;
127	unsigned long __user *uaddr =
128			(unsigned long __user *)(unsigned long)reg->addr;
129	unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
130					    KVM_REG_SIZE_MASK |
131					    rtype);
132	void *reg_val;
133
134	if ((rtype == KVM_REG_RISCV_FP_F) &&
135	    riscv_isa_extension_available(vcpu->arch.isa, f)) {
136		if (KVM_REG_SIZE(reg->id) != sizeof(u32))
137			return -EINVAL;
138		if (reg_num == KVM_REG_RISCV_FP_F_REG(fcsr))
139			reg_val = &cntx->fp.f.fcsr;
140		else if ((KVM_REG_RISCV_FP_F_REG(f[0]) <= reg_num) &&
141			  reg_num <= KVM_REG_RISCV_FP_F_REG(f[31]))
142			reg_val = &cntx->fp.f.f[reg_num];
143		else
144			return -ENOENT;
145	} else if ((rtype == KVM_REG_RISCV_FP_D) &&
146		   riscv_isa_extension_available(vcpu->arch.isa, d)) {
147		if (reg_num == KVM_REG_RISCV_FP_D_REG(fcsr)) {
148			if (KVM_REG_SIZE(reg->id) != sizeof(u32))
149				return -EINVAL;
150			reg_val = &cntx->fp.d.fcsr;
151		} else if ((KVM_REG_RISCV_FP_D_REG(f[0]) <= reg_num) &&
152			   reg_num <= KVM_REG_RISCV_FP_D_REG(f[31])) {
153			if (KVM_REG_SIZE(reg->id) != sizeof(u64))
154				return -EINVAL;
155			reg_val = &cntx->fp.d.f[reg_num];
156		} else
157			return -ENOENT;
158	} else
159		return -ENOENT;
160
161	if (copy_from_user(reg_val, uaddr, KVM_REG_SIZE(reg->id)))
162		return -EFAULT;
163
164	return 0;
165}
166