xref: /linux/arch/riscv/include/asm/mmio.h (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * {read,write}{b,w,l,q} based on arch/arm64/include/asm/io.h
4  *   which was based on arch/arm/include/io.h
5  *
6  * Copyright (C) 1996-2000 Russell King
7  * Copyright (C) 2012 ARM Ltd.
8  * Copyright (C) 2014 Regents of the University of California
9  */
10 
11 #ifndef _ASM_RISCV_MMIO_H
12 #define _ASM_RISCV_MMIO_H
13 
14 #include <linux/types.h>
15 #include <asm/fence.h>
16 #include <asm/mmiowb.h>
17 
18 /* Generic IO read/write.  These perform native-endian accesses. */
19 #define __raw_writeb __raw_writeb
20 static inline void __raw_writeb(u8 val, volatile void __iomem *addr)
21 {
22 	asm volatile("sb %0, 0(%1)" : : "r" (val), "r" (addr));
23 }
24 
25 #define __raw_writew __raw_writew
26 static inline void __raw_writew(u16 val, volatile void __iomem *addr)
27 {
28 	asm volatile("sh %0, 0(%1)" : : "r" (val), "r" (addr));
29 }
30 
31 #define __raw_writel __raw_writel
32 static inline void __raw_writel(u32 val, volatile void __iomem *addr)
33 {
34 	asm volatile("sw %0, 0(%1)" : : "r" (val), "r" (addr));
35 }
36 
37 #ifdef CONFIG_64BIT
38 #define __raw_writeq __raw_writeq
39 static inline void __raw_writeq(u64 val, volatile void __iomem *addr)
40 {
41 	asm volatile("sd %0, 0(%1)" : : "r" (val), "r" (addr));
42 }
43 #endif
44 
45 #define __raw_readb __raw_readb
46 static inline u8 __raw_readb(const volatile void __iomem *addr)
47 {
48 	u8 val;
49 
50 	asm volatile("lb %0, 0(%1)" : "=r" (val) : "r" (addr));
51 	return val;
52 }
53 
54 #define __raw_readw __raw_readw
55 static inline u16 __raw_readw(const volatile void __iomem *addr)
56 {
57 	u16 val;
58 
59 	asm volatile("lh %0, 0(%1)" : "=r" (val) : "r" (addr));
60 	return val;
61 }
62 
63 #define __raw_readl __raw_readl
64 static inline u32 __raw_readl(const volatile void __iomem *addr)
65 {
66 	u32 val;
67 
68 	asm volatile("lw %0, 0(%1)" : "=r" (val) : "r" (addr));
69 	return val;
70 }
71 
72 #ifdef CONFIG_64BIT
73 #define __raw_readq __raw_readq
74 static inline u64 __raw_readq(const volatile void __iomem *addr)
75 {
76 	u64 val;
77 
78 	asm volatile("ld %0, 0(%1)" : "=r" (val) : "r" (addr));
79 	return val;
80 }
81 #endif
82 
83 /*
84  * Unordered I/O memory access primitives.  These are even more relaxed than
85  * the relaxed versions, as they don't even order accesses between successive
86  * operations to the I/O regions.
87  */
88 #define readb_cpu(c)		({ u8  __r = __raw_readb(c); __r; })
89 #define readw_cpu(c)		({ u16 __r = le16_to_cpu((__force __le16)__raw_readw(c)); __r; })
90 #define readl_cpu(c)		({ u32 __r = le32_to_cpu((__force __le32)__raw_readl(c)); __r; })
91 
92 #define writeb_cpu(v, c)	((void)__raw_writeb((v), (c)))
93 #define writew_cpu(v, c)	((void)__raw_writew((__force u16)cpu_to_le16(v), (c)))
94 #define writel_cpu(v, c)	((void)__raw_writel((__force u32)cpu_to_le32(v), (c)))
95 
96 #ifdef CONFIG_64BIT
97 #define readq_cpu(c)		({ u64 __r = le64_to_cpu((__force __le64)__raw_readq(c)); __r; })
98 #define writeq_cpu(v, c)	((void)__raw_writeq((__force u64)cpu_to_le64(v), (c)))
99 #endif
100 
101 /*
102  * Relaxed I/O memory access primitives. These follow the Device memory
103  * ordering rules but do not guarantee any ordering relative to Normal memory
104  * accesses.  These are defined to order the indicated access (either a read or
105  * write) with all other I/O memory accesses to the same peripheral. Since the
106  * platform specification defines that all I/O regions are strongly ordered on
107  * channel 0, no explicit fences are required to enforce this ordering.
108  */
109 /* FIXME: These are now the same as asm-generic */
110 #define __io_rbr()		do {} while (0)
111 #define __io_rar()		do {} while (0)
112 #define __io_rbw()		do {} while (0)
113 #define __io_raw()		do {} while (0)
114 
115 #define readb_relaxed(c)	({ u8  __v; __io_rbr(); __v = readb_cpu(c); __io_rar(); __v; })
116 #define readw_relaxed(c)	({ u16 __v; __io_rbr(); __v = readw_cpu(c); __io_rar(); __v; })
117 #define readl_relaxed(c)	({ u32 __v; __io_rbr(); __v = readl_cpu(c); __io_rar(); __v; })
118 
119 #define writeb_relaxed(v, c)	({ __io_rbw(); writeb_cpu((v), (c)); __io_raw(); })
120 #define writew_relaxed(v, c)	({ __io_rbw(); writew_cpu((v), (c)); __io_raw(); })
121 #define writel_relaxed(v, c)	({ __io_rbw(); writel_cpu((v), (c)); __io_raw(); })
122 
123 #ifdef CONFIG_64BIT
124 #define readq_relaxed(c)	({ u64 __v; __io_rbr(); __v = readq_cpu(c); __io_rar(); __v; })
125 #define writeq_relaxed(v, c)	({ __io_rbw(); writeq_cpu((v), (c)); __io_raw(); })
126 #endif
127 
128 /*
129  * I/O memory access primitives.  Reads are ordered relative to any following
130  * Normal memory read and delay() loop.  Writes are ordered relative to any
131  * prior Normal memory write.  The memory barriers here are necessary as RISC-V
132  * doesn't define any ordering between the memory space and the I/O space.
133  */
134 #define __io_br()	do {} while (0)
135 #define __io_ar(v)	RISCV_FENCE(i, ir)
136 #define __io_bw()	RISCV_FENCE(w, o)
137 #define __io_aw()	mmiowb_set_pending()
138 
139 #define readb(c)	({ u8  __v; __io_br(); __v = readb_cpu(c); __io_ar(__v); __v; })
140 #define readw(c)	({ u16 __v; __io_br(); __v = readw_cpu(c); __io_ar(__v); __v; })
141 #define readl(c)	({ u32 __v; __io_br(); __v = readl_cpu(c); __io_ar(__v); __v; })
142 
143 #define writeb(v, c)	({ __io_bw(); writeb_cpu((v), (c)); __io_aw(); })
144 #define writew(v, c)	({ __io_bw(); writew_cpu((v), (c)); __io_aw(); })
145 #define writel(v, c)	({ __io_bw(); writel_cpu((v), (c)); __io_aw(); })
146 
147 #ifdef CONFIG_64BIT
148 #define readq(c)	({ u64 __v; __io_br(); __v = readq_cpu(c); __io_ar(__v); __v; })
149 #define writeq(v, c)	({ __io_bw(); writeq_cpu((v), (c)); __io_aw(); })
150 #endif
151 
152 #endif /* _ASM_RISCV_MMIO_H */
153