xref: /kernel/linux/linux-5.10/arch/riscv/include/asm/io.h (revision 8c2ecf20)
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#include <asm/early_ioremap.h>
18
19/*
20 * MMIO access functions are separated out to break dependency cycles
21 * when using {read,write}* fns in low-level headers
22 */
23#include <asm/mmio.h>
24
25/*
26 *  I/O port access constants.
27 */
28#ifdef CONFIG_MMU
29#define IO_SPACE_LIMIT		(PCI_IO_SIZE - 1)
30#define PCI_IOBASE		((void __iomem *)PCI_IO_START)
31#endif /* CONFIG_MMU */
32
33/*
34 * Emulation routines for the port-mapped IO space used by some PCI drivers.
35 * These are defined as being "fully synchronous", but also "not guaranteed to
36 * be fully ordered with respect to other memory and I/O operations".  We're
37 * going to be on the safe side here and just make them:
38 *  - Fully ordered WRT each other, by bracketing them with two fences.  The
39 *    outer set contains both I/O so inX is ordered with outX, while the inner just
40 *    needs the type of the access (I for inX and O for outX).
41 *  - Ordered in the same manner as readX/writeX WRT memory by subsuming their
42 *    fences.
43 *  - Ordered WRT timer reads, so udelay and friends don't get elided by the
44 *    implementation.
45 * Note that there is no way to actually enforce that outX is a non-posted
46 * operation on RISC-V, but hopefully the timer ordering constraint is
47 * sufficient to ensure this works sanely on controllers that support I/O
48 * writes.
49 */
50#define __io_pbr()	__asm__ __volatile__ ("fence io,i"  : : : "memory");
51#define __io_par(v)	__asm__ __volatile__ ("fence i,ior" : : : "memory");
52#define __io_pbw()	__asm__ __volatile__ ("fence iow,o" : : : "memory");
53#define __io_paw()	__asm__ __volatile__ ("fence o,io"  : : : "memory");
54
55#define inb(c)		({ u8  __v; __io_pbr(); __v = readb_cpu((void*)(PCI_IOBASE + (c))); __io_par(__v); __v; })
56#define inw(c)		({ u16 __v; __io_pbr(); __v = readw_cpu((void*)(PCI_IOBASE + (c))); __io_par(__v); __v; })
57#define inl(c)		({ u32 __v; __io_pbr(); __v = readl_cpu((void*)(PCI_IOBASE + (c))); __io_par(__v); __v; })
58
59#define outb(v,c)	({ __io_pbw(); writeb_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); })
60#define outw(v,c)	({ __io_pbw(); writew_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); })
61#define outl(v,c)	({ __io_pbw(); writel_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); })
62
63#ifdef CONFIG_64BIT
64#define inq(c)		({ u64 __v; __io_pbr(); __v = readq_cpu((void*)(c)); __io_par(__v); __v; })
65#define outq(v,c)	({ __io_pbw(); writeq_cpu((v),(void*)(c)); __io_paw(); })
66#endif
67
68/*
69 * Accesses from a single hart to a single I/O address must be ordered.  This
70 * allows us to use the raw read macros, but we still need to fence before and
71 * after the block to ensure ordering WRT other macros.  These are defined to
72 * perform host-endian accesses so we use __raw instead of __cpu.
73 */
74#define __io_reads_ins(port, ctype, len, bfence, afence)			\
75	static inline void __ ## port ## len(const volatile void __iomem *addr,	\
76					     void *buffer,			\
77					     unsigned int count)		\
78	{									\
79		bfence;								\
80		if (count) {							\
81			ctype *buf = buffer;					\
82										\
83			do {							\
84				ctype x = __raw_read ## len(addr);		\
85				*buf++ = x;					\
86			} while (--count);					\
87		}								\
88		afence;								\
89	}
90
91#define __io_writes_outs(port, ctype, len, bfence, afence)			\
92	static inline void __ ## port ## len(volatile void __iomem *addr,	\
93					     const void *buffer,		\
94					     unsigned int count)		\
95	{									\
96		bfence;								\
97		if (count) {							\
98			const ctype *buf = buffer;				\
99										\
100			do {							\
101				__raw_write ## len(*buf++, addr);		\
102			} while (--count);					\
103		}								\
104		afence;								\
105	}
106
107__io_reads_ins(reads,  u8, b, __io_br(), __io_ar(addr))
108__io_reads_ins(reads, u16, w, __io_br(), __io_ar(addr))
109__io_reads_ins(reads, u32, l, __io_br(), __io_ar(addr))
110#define readsb(addr, buffer, count) __readsb(addr, buffer, count)
111#define readsw(addr, buffer, count) __readsw(addr, buffer, count)
112#define readsl(addr, buffer, count) __readsl(addr, buffer, count)
113
114__io_reads_ins(ins,  u8, b, __io_pbr(), __io_par(addr))
115__io_reads_ins(ins, u16, w, __io_pbr(), __io_par(addr))
116__io_reads_ins(ins, u32, l, __io_pbr(), __io_par(addr))
117#define insb(addr, buffer, count) __insb(PCI_IOBASE + (addr), buffer, count)
118#define insw(addr, buffer, count) __insw(PCI_IOBASE + (addr), buffer, count)
119#define insl(addr, buffer, count) __insl(PCI_IOBASE + (addr), buffer, count)
120
121__io_writes_outs(writes,  u8, b, __io_bw(), __io_aw())
122__io_writes_outs(writes, u16, w, __io_bw(), __io_aw())
123__io_writes_outs(writes, u32, l, __io_bw(), __io_aw())
124#define writesb(addr, buffer, count) __writesb(addr, buffer, count)
125#define writesw(addr, buffer, count) __writesw(addr, buffer, count)
126#define writesl(addr, buffer, count) __writesl(addr, buffer, count)
127
128__io_writes_outs(outs,  u8, b, __io_pbw(), __io_paw())
129__io_writes_outs(outs, u16, w, __io_pbw(), __io_paw())
130__io_writes_outs(outs, u32, l, __io_pbw(), __io_paw())
131#define outsb(addr, buffer, count) __outsb(PCI_IOBASE + (addr), buffer, count)
132#define outsw(addr, buffer, count) __outsw(PCI_IOBASE + (addr), buffer, count)
133#define outsl(addr, buffer, count) __outsl(PCI_IOBASE + (addr), buffer, count)
134
135#ifdef CONFIG_64BIT
136__io_reads_ins(reads, u64, q, __io_br(), __io_ar(addr))
137#define readsq(addr, buffer, count) __readsq(addr, buffer, count)
138
139__io_reads_ins(ins, u64, q, __io_pbr(), __io_par(addr))
140#define insq(addr, buffer, count) __insq(PCI_IOBASE + (addr), buffer, count)
141
142__io_writes_outs(writes, u64, q, __io_bw(), __io_aw())
143#define writesq(addr, buffer, count) __writesq(addr, buffer, count)
144
145__io_writes_outs(outs, u64, q, __io_pbr(), __io_paw())
146#define outsq(addr, buffer, count) __outsq(PCI_IOBASE + (addr), buffer, count)
147#endif
148
149#include <asm-generic/io.h>
150
151#endif /* _ASM_RISCV_IO_H */
152