xref: /openbmc/linux/arch/riscv/include/asm/io.h (revision 04b3c795)
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_IO_H
12 #define _ASM_RISCV_IO_H
13 
14 #include <linux/types.h>
15 #include <linux/pgtable.h>
16 #include <asm/mmiowb.h>
17 
18 /*
19  * MMIO access functions are separated out to break dependency cycles
20  * when using {read,write}* fns in low-level headers
21  */
22 #include <asm/mmio.h>
23 
24 /*
25  *  I/O port access constants.
26  */
27 #ifdef CONFIG_MMU
28 #define IO_SPACE_LIMIT		(PCI_IO_SIZE - 1)
29 #define PCI_IOBASE		((void __iomem *)PCI_IO_START)
30 #endif /* CONFIG_MMU */
31 
32 /*
33  * Emulation routines for the port-mapped IO space used by some PCI drivers.
34  * These are defined as being "fully synchronous", but also "not guaranteed to
35  * be fully ordered with respect to other memory and I/O operations".  We're
36  * going to be on the safe side here and just make them:
37  *  - Fully ordered WRT each other, by bracketing them with two fences.  The
38  *    outer set contains both I/O so inX is ordered with outX, while the inner just
39  *    needs the type of the access (I for inX and O for outX).
40  *  - Ordered in the same manner as readX/writeX WRT memory by subsuming their
41  *    fences.
42  *  - Ordered WRT timer reads, so udelay and friends don't get elided by the
43  *    implementation.
44  * Note that there is no way to actually enforce that outX is a non-posted
45  * operation on RISC-V, but hopefully the timer ordering constraint is
46  * sufficient to ensure this works sanely on controllers that support I/O
47  * writes.
48  */
49 #define __io_pbr()	__asm__ __volatile__ ("fence io,i"  : : : "memory");
50 #define __io_par(v)	__asm__ __volatile__ ("fence i,ior" : : : "memory");
51 #define __io_pbw()	__asm__ __volatile__ ("fence iow,o" : : : "memory");
52 #define __io_paw()	__asm__ __volatile__ ("fence o,io"  : : : "memory");
53 
54 #define inb(c)		({ u8  __v; __io_pbr(); __v = readb_cpu((void*)(PCI_IOBASE + (c))); __io_par(__v); __v; })
55 #define inw(c)		({ u16 __v; __io_pbr(); __v = readw_cpu((void*)(PCI_IOBASE + (c))); __io_par(__v); __v; })
56 #define inl(c)		({ u32 __v; __io_pbr(); __v = readl_cpu((void*)(PCI_IOBASE + (c))); __io_par(__v); __v; })
57 
58 #define outb(v,c)	({ __io_pbw(); writeb_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); })
59 #define outw(v,c)	({ __io_pbw(); writew_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); })
60 #define outl(v,c)	({ __io_pbw(); writel_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); })
61 
62 #ifdef CONFIG_64BIT
63 #define inq(c)		({ u64 __v; __io_pbr(); __v = readq_cpu((void*)(c)); __io_par(__v); __v; })
64 #define outq(v,c)	({ __io_pbw(); writeq_cpu((v),(void*)(c)); __io_paw(); })
65 #endif
66 
67 /*
68  * Accesses from a single hart to a single I/O address must be ordered.  This
69  * allows us to use the raw read macros, but we still need to fence before and
70  * after the block to ensure ordering WRT other macros.  These are defined to
71  * perform host-endian accesses so we use __raw instead of __cpu.
72  */
73 #define __io_reads_ins(port, ctype, len, bfence, afence)			\
74 	static inline void __ ## port ## len(const volatile void __iomem *addr,	\
75 					     void *buffer,			\
76 					     unsigned int count)		\
77 	{									\
78 		bfence;								\
79 		if (count) {							\
80 			ctype *buf = buffer;					\
81 										\
82 			do {							\
83 				ctype x = __raw_read ## len(addr);		\
84 				*buf++ = x;					\
85 			} while (--count);					\
86 		}								\
87 		afence;								\
88 	}
89 
90 #define __io_writes_outs(port, ctype, len, bfence, afence)			\
91 	static inline void __ ## port ## len(volatile void __iomem *addr,	\
92 					     const void *buffer,		\
93 					     unsigned int count)		\
94 	{									\
95 		bfence;								\
96 		if (count) {							\
97 			const ctype *buf = buffer;				\
98 										\
99 			do {							\
100 				__raw_write ## len(*buf++, addr);		\
101 			} while (--count);					\
102 		}								\
103 		afence;								\
104 	}
105 
106 __io_reads_ins(reads,  u8, b, __io_br(), __io_ar(addr))
107 __io_reads_ins(reads, u16, w, __io_br(), __io_ar(addr))
108 __io_reads_ins(reads, u32, l, __io_br(), __io_ar(addr))
109 #define readsb(addr, buffer, count) __readsb(addr, buffer, count)
110 #define readsw(addr, buffer, count) __readsw(addr, buffer, count)
111 #define readsl(addr, buffer, count) __readsl(addr, buffer, count)
112 
113 __io_reads_ins(ins,  u8, b, __io_pbr(), __io_par(addr))
114 __io_reads_ins(ins, u16, w, __io_pbr(), __io_par(addr))
115 __io_reads_ins(ins, u32, l, __io_pbr(), __io_par(addr))
116 #define insb(addr, buffer, count) __insb((void __iomem *)(long)addr, buffer, count)
117 #define insw(addr, buffer, count) __insw((void __iomem *)(long)addr, buffer, count)
118 #define insl(addr, buffer, count) __insl((void __iomem *)(long)addr, buffer, count)
119 
120 __io_writes_outs(writes,  u8, b, __io_bw(), __io_aw())
121 __io_writes_outs(writes, u16, w, __io_bw(), __io_aw())
122 __io_writes_outs(writes, u32, l, __io_bw(), __io_aw())
123 #define writesb(addr, buffer, count) __writesb(addr, buffer, count)
124 #define writesw(addr, buffer, count) __writesw(addr, buffer, count)
125 #define writesl(addr, buffer, count) __writesl(addr, buffer, count)
126 
127 __io_writes_outs(outs,  u8, b, __io_pbw(), __io_paw())
128 __io_writes_outs(outs, u16, w, __io_pbw(), __io_paw())
129 __io_writes_outs(outs, u32, l, __io_pbw(), __io_paw())
130 #define outsb(addr, buffer, count) __outsb((void __iomem *)(long)addr, buffer, count)
131 #define outsw(addr, buffer, count) __outsw((void __iomem *)(long)addr, buffer, count)
132 #define outsl(addr, buffer, count) __outsl((void __iomem *)(long)addr, buffer, count)
133 
134 #ifdef CONFIG_64BIT
135 __io_reads_ins(reads, u64, q, __io_br(), __io_ar(addr))
136 #define readsq(addr, buffer, count) __readsq(addr, buffer, count)
137 
138 __io_reads_ins(ins, u64, q, __io_pbr(), __io_par(addr))
139 #define insq(addr, buffer, count) __insq((void __iomem *)addr, buffer, count)
140 
141 __io_writes_outs(writes, u64, q, __io_bw(), __io_aw())
142 #define writesq(addr, buffer, count) __writesq(addr, buffer, count)
143 
144 __io_writes_outs(outs, u64, q, __io_pbr(), __io_paw())
145 #define outsq(addr, buffer, count) __outsq((void __iomem *)addr, buffer, count)
146 #endif
147 
148 #include <asm-generic/io.h>
149 
150 #endif /* _ASM_RISCV_IO_H */
151