xref: /netbsd-src/sys/arch/riscv/include/sysreg.h (revision 8ecbf5f02b752fcb7debe1a8fab1dc82602bc760)
1 /* $NetBSD: sysreg.h,v 1.5 2020/03/14 16:12:16 skrll Exp $ */
2 
3 /*
4  * Copyright (c) 2014 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Matt Thomas of 3am Software Foundry.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #ifndef _RISCV_SYSREG_H_
33 #define _RISCV_SYSREG_H_
34 
35 #ifndef _KERNEL
36 #include <sys/param.h>
37 #endif
38 
39 #define FCSR_FMASK	0	// no exception bits
40 #define FCSR_FRM	__BITS(7,5)
41 #define FCSR_FRM_RNE	0b000	// Round Nearest, ties to Even
42 #define FCSR_FRM_RTZ	0b001	// Round Towards Zero
43 #define FCSR_FRM_RDN	0b010	// Round DowN (-infinity)
44 #define FCSR_FRM_RUP	0b011	// Round UP (+infinity)
45 #define FCSR_FRM_RMM	0b100	// Round to nearest, ties to Max Magnitude
46 #define FCSR_FFLAGS	__BITS(4,0)	// Sticky bits
47 #define FCSR_NV		__BIT(4)	// iNValid operation
48 #define FCSR_DZ		__BIT(3)	// Divide by Zero
49 #define FCSR_OF		__BIT(2)	// OverFlow
50 #define FCSR_UF		__BIT(1)	// UnderFlow
51 #define FCSR_NX		__BIT(0)	// iNeXact
52 
53 static inline uint32_t
54 riscvreg_fcsr_read(void)
55 {
56 	uint32_t __fcsr;
57 	__asm("frcsr %0" : "=r"(__fcsr));
58 	return __fcsr;
59 }
60 
61 
62 static inline uint32_t
63 riscvreg_fcsr_write(uint32_t __new)
64 {
65 	uint32_t __old;
66 	__asm("fscsr %0, %1" : "=r"(__old) : "r"(__new));
67 	return __old;
68 }
69 
70 static inline uint32_t
71 riscvreg_fcsr_read_fflags(void)
72 {
73 	uint32_t __old;
74 	__asm("frflags %0" : "=r"(__old));
75 	return __SHIFTOUT(__old, FCSR_FFLAGS);
76 }
77 
78 static inline uint32_t
79 riscvreg_fcsr_write_fflags(uint32_t __new)
80 {
81 	uint32_t __old;
82 	__new = __SHIFTIN(__new, FCSR_FFLAGS);
83 	__asm("fsflags %0, %1" : "=r"(__old) : "r"(__new));
84 	return __SHIFTOUT(__old, FCSR_FFLAGS);
85 }
86 
87 static inline uint32_t
88 riscvreg_fcsr_read_frm(void)
89 {
90 	uint32_t __old;
91 	__asm("frrm\t%0" : "=r"(__old));
92 	return __SHIFTOUT(__old, FCSR_FRM);
93 }
94 
95 static inline uint32_t
96 riscvreg_fcsr_write_frm(uint32_t __new)
97 {
98 	uint32_t __old;
99 	__new = __SHIFTIN(__new, FCSR_FRM);
100 	__asm volatile("fsrm\t%0, %1" : "=r"(__old) : "r"(__new));
101 	return __SHIFTOUT(__old, FCSR_FRM);
102 }
103 
104 // Status Register
105 #define SR_IP		__BITS(31,24)	// Pending interrupts
106 #define SR_IM		__BITS(23,16)	// Interrupt Mask
107 #define SR_VM		__BIT(7)	// MMU On
108 #define SR_S64		__BIT(6)	// RV64 supervisor mode
109 #define SR_U64		__BIT(5)	// RV64 user mode
110 #define SR_EF		__BIT(4)	// Enable Floating Point
111 #define SR_PEI		__BIT(3)	// Previous EI setting
112 #define SR_EI		__BIT(2)	// Enable interrupts
113 #define SR_PS		__BIT(1)	// Previous (S) supervisor setting
114 #define SR_S		__BIT(0)	// Supervisor
115 
116 #ifdef _LP64
117 #define	SR_USER		(SR_EI|SR_U64|SR_S64|SR_VM|SR_IM)
118 #define	SR_USER32	(SR_USER & ~SR_U64)
119 #define	SR_KERNEL	(SR_S|SR_EI|SR_U64|SR_S64|SR_VM)
120 #else
121 #define	SR_USER		(SR_EI|SR_VM|SR_IM)
122 #define	SR_KERNEL	(SR_S|SR_EI|SR_VM)
123 #endif
124 
125 static inline uint32_t
126 riscvreg_status_read(void)
127 {
128 	uint32_t __sr;
129 	__asm("csrr\t%0, sstatus" : "=r"(__sr));
130 	return __sr;
131 }
132 
133 static inline uint32_t
134 riscvreg_status_clear(uint32_t __mask)
135 {
136 	uint32_t __sr;
137 	if (__builtin_constant_p(__mask) && __mask < 0x20) {
138 		__asm("csrrci\t%0, sstatus, %1" : "=r"(__sr) : "i"(__mask));
139 	} else {
140 		__asm("csrrc\t%0, sstatus, %1" : "=r"(__sr) : "r"(__mask));
141 	}
142 	return __sr;
143 }
144 
145 static inline uint32_t
146 riscvreg_status_set(uint32_t __mask)
147 {
148 	uint32_t __sr;
149 	if (__builtin_constant_p(__mask) && __mask < 0x20) {
150 		__asm("csrrsi\t%0, sstatus, %1" : "=r"(__sr) : "i"(__mask));
151 	} else {
152 		__asm("csrrs\t%0, sstatus, %1" : "=r"(__sr) : "r"(__mask));
153 	}
154 	return __sr;
155 }
156 
157 // Cause register
158 #define CAUSE_MISALIGNED_FETCH		0
159 #define CAUSE_FAULT_FETCH		1
160 #define CAUSE_ILLEGAL_INSTRUCTION	2
161 #define CAUSE_PRIVILEGED_INSTRUCTION	3
162 #define CAUSE_MISALIGNED_LOAD		4
163 #define CAUSE_FAULT_LOAD		5
164 #define CAUSE_MISALIGNED_STORE		6
165 #define CAUSE_FAULT_STORE		7
166 #define CAUSE_SYSCALL			8
167 #define CAUSE_BREAKPOINT		9
168 #define CAUSE_FP_DISABLED		10
169 #define CAUSE_ACCELERATOR_DISABLED	12
170 
171 static inline uint64_t
172 riscvreg_cycle_read(void)
173 {
174 #ifdef _LP64
175 	uint64_t __lo;
176 	__asm __volatile("csrr\t%0, cycle" : "=r"(__lo));
177 	return __lo;
178 #else
179 	uint32_t __hi0, __hi1, __lo0;
180 	do {
181 		__asm __volatile(
182 			"csrr\t%[__hi0], cycleh"
183 		"\n\t"	"csrr\t%[__lo0], cycle"
184 		"\n\t"	"csrr\t%[__hi1], cycleh"
185 		   :	[__hi0] "=r"(__hi0),
186 			[__lo0] "=r"(__lo0),
187 			[__hi1] "=r"(__hi1));
188 	} while (__hi0 != __hi1);
189 	return ((uint64_t)__hi0 << 32) | (uint64_t)__lo0;
190 #endif
191 }
192 
193 #ifdef _LP64
194 #define SATP_MODE	__BITS(63,60)
195 #define SATP_ASID	__BITS(59,44)
196 #define SATP_PPN	__BITS(43,0)
197 #else
198 #define SATP_MODE	__BIT(31)
199 #define SATP_ASID	__BITS(30,22)
200 #define SATP_PPN	__BITS(21,0)
201 #endif
202 
203 static inline uint32_t
204 riscvreg_asid_read(void)
205 {
206 	uintptr_t satp;
207 	__asm __volatile("csrr	%0, satp" : "=r" (satp));
208 	return __SHIFTOUT(satp, SATP_ASID);
209 }
210 
211 static inline void
212 riscvreg_asid_write(uint32_t asid)
213 {
214 	uintptr_t satp;
215 	__asm __volatile("csrr	%0, satp" : "=r" (satp));
216 	satp &= ~SATP_ASID;
217 	satp |= __SHIFTIN((uintptr_t)asid, SATP_ASID);
218 	__asm __volatile("csrw	satp, %0" :: "r" (satp));
219 }
220 
221 #endif /* _RISCV_SYSREG_H_ */
222