xref: /openbmc/linux/arch/riscv/include/asm/mmio.h (revision 842ed298)
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/mmiowb.h>
16 
17 /* Generic IO read/write.  These perform native-endian accesses. */
18 #define __raw_writeb __raw_writeb
19 static inline void __raw_writeb(u8 val, volatile void __iomem *addr)
20 {
21 	asm volatile("sb %0, 0(%1)" : : "r" (val), "r" (addr));
22 }
23 
24 #define __raw_writew __raw_writew
25 static inline void __raw_writew(u16 val, volatile void __iomem *addr)
26 {
27 	asm volatile("sh %0, 0(%1)" : : "r" (val), "r" (addr));
28 }
29 
30 #define __raw_writel __raw_writel
31 static inline void __raw_writel(u32 val, volatile void __iomem *addr)
32 {
33 	asm volatile("sw %0, 0(%1)" : : "r" (val), "r" (addr));
34 }
35 
36 #ifdef CONFIG_64BIT
37 #define __raw_writeq __raw_writeq
38 static inline void __raw_writeq(u64 val, volatile void __iomem *addr)
39 {
40 	asm volatile("sd %0, 0(%1)" : : "r" (val), "r" (addr));
41 }
42 #endif
43 
44 #define __raw_readb __raw_readb
45 static inline u8 __raw_readb(const volatile void __iomem *addr)
46 {
47 	u8 val;
48 
49 	asm volatile("lb %0, 0(%1)" : "=r" (val) : "r" (addr));
50 	return val;
51 }
52 
53 #define __raw_readw __raw_readw
54 static inline u16 __raw_readw(const volatile void __iomem *addr)
55 {
56 	u16 val;
57 
58 	asm volatile("lh %0, 0(%1)" : "=r" (val) : "r" (addr));
59 	return val;
60 }
61 
62 #define __raw_readl __raw_readl
63 static inline u32 __raw_readl(const volatile void __iomem *addr)
64 {
65 	u32 val;
66 
67 	asm volatile("lw %0, 0(%1)" : "=r" (val) : "r" (addr));
68 	return val;
69 }
70 
71 #ifdef CONFIG_64BIT
72 #define __raw_readq __raw_readq
73 static inline u64 __raw_readq(const volatile void __iomem *addr)
74 {
75 	u64 val;
76 
77 	asm volatile("ld %0, 0(%1)" : "=r" (val) : "r" (addr));
78 	return val;
79 }
80 #endif
81 
82 /*
83  * Unordered I/O memory access primitives.  These are even more relaxed than
84  * the relaxed versions, as they don't even order accesses between successive
85  * operations to the I/O regions.
86  */
87 #define readb_cpu(c)		({ u8  __r = __raw_readb(c); __r; })
88 #define readw_cpu(c)		({ u16 __r = le16_to_cpu((__force __le16)__raw_readw(c)); __r; })
89 #define readl_cpu(c)		({ u32 __r = le32_to_cpu((__force __le32)__raw_readl(c)); __r; })
90 
91 #define writeb_cpu(v, c)	((void)__raw_writeb((v), (c)))
92 #define writew_cpu(v, c)	((void)__raw_writew((__force u16)cpu_to_le16(v), (c)))
93 #define writel_cpu(v, c)	((void)__raw_writel((__force u32)cpu_to_le32(v), (c)))
94 
95 #ifdef CONFIG_64BIT
96 #define readq_cpu(c)		({ u64 __r = le64_to_cpu((__force __le64)__raw_readq(c)); __r; })
97 #define writeq_cpu(v, c)	((void)__raw_writeq((__force u64)cpu_to_le64(v), (c)))
98 #endif
99 
100 /*
101  * Relaxed I/O memory access primitives. These follow the Device memory
102  * ordering rules but do not guarantee any ordering relative to Normal memory
103  * accesses.  These are defined to order the indicated access (either a read or
104  * write) with all other I/O memory accesses. Since the platform specification
105  * defines that all I/O regions are strongly ordered on channel 2, no explicit
106  * fences are required to enforce this ordering.
107  */
108 /* FIXME: These are now the same as asm-generic */
109 #define __io_rbr()		do {} while (0)
110 #define __io_rar()		do {} while (0)
111 #define __io_rbw()		do {} while (0)
112 #define __io_raw()		do {} while (0)
113 
114 #define readb_relaxed(c)	({ u8  __v; __io_rbr(); __v = readb_cpu(c); __io_rar(); __v; })
115 #define readw_relaxed(c)	({ u16 __v; __io_rbr(); __v = readw_cpu(c); __io_rar(); __v; })
116 #define readl_relaxed(c)	({ u32 __v; __io_rbr(); __v = readl_cpu(c); __io_rar(); __v; })
117 
118 #define writeb_relaxed(v, c)	({ __io_rbw(); writeb_cpu((v), (c)); __io_raw(); })
119 #define writew_relaxed(v, c)	({ __io_rbw(); writew_cpu((v), (c)); __io_raw(); })
120 #define writel_relaxed(v, c)	({ __io_rbw(); writel_cpu((v), (c)); __io_raw(); })
121 
122 #ifdef CONFIG_64BIT
123 #define readq_relaxed(c)	({ u64 __v; __io_rbr(); __v = readq_cpu(c); __io_rar(); __v; })
124 #define writeq_relaxed(v, c)	({ __io_rbw(); writeq_cpu((v), (c)); __io_raw(); })
125 #endif
126 
127 /*
128  * I/O memory access primitives. Reads are ordered relative to any
129  * following Normal memory access. Writes are ordered relative to any prior
130  * Normal memory access.  The memory barriers here are necessary as RISC-V
131  * doesn't define any ordering between the memory space and the I/O space.
132  */
133 #define __io_br()	do {} while (0)
134 #define __io_ar(v)	__asm__ __volatile__ ("fence i,r" : : : "memory")
135 #define __io_bw()	__asm__ __volatile__ ("fence w,o" : : : "memory")
136 #define __io_aw()	mmiowb_set_pending()
137 
138 #define readb(c)	({ u8  __v; __io_br(); __v = readb_cpu(c); __io_ar(__v); __v; })
139 #define readw(c)	({ u16 __v; __io_br(); __v = readw_cpu(c); __io_ar(__v); __v; })
140 #define readl(c)	({ u32 __v; __io_br(); __v = readl_cpu(c); __io_ar(__v); __v; })
141 
142 #define writeb(v, c)	({ __io_bw(); writeb_cpu((v), (c)); __io_aw(); })
143 #define writew(v, c)	({ __io_bw(); writew_cpu((v), (c)); __io_aw(); })
144 #define writel(v, c)	({ __io_bw(); writel_cpu((v), (c)); __io_aw(); })
145 
146 #ifdef CONFIG_64BIT
147 #define readq(c)	({ u64 __v; __io_br(); __v = readq_cpu(c); __io_ar(__v); __v; })
148 #define writeq(v, c)	({ __io_bw(); writeq_cpu((v), (c)); __io_aw(); })
149 #endif
150 
151 #endif /* _ASM_RISCV_MMIO_H */
152