xref: /openbmc/linux/arch/arc/include/asm/io.h (revision 3e26a691)
1 /*
2  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8 
9 #ifndef _ASM_ARC_IO_H
10 #define _ASM_ARC_IO_H
11 
12 #include <linux/types.h>
13 #include <asm/byteorder.h>
14 #include <asm/page.h>
15 
16 extern void __iomem *ioremap(phys_addr_t paddr, unsigned long size);
17 extern void __iomem *ioremap_prot(phys_addr_t paddr, unsigned long size,
18 				  unsigned long flags);
19 static inline void __iomem *ioport_map(unsigned long port, unsigned int nr)
20 {
21 	return (void __iomem *)port;
22 }
23 
24 static inline void ioport_unmap(void __iomem *addr)
25 {
26 }
27 
28 extern void iounmap(const void __iomem *addr);
29 
30 #define ioremap_nocache(phy, sz)	ioremap(phy, sz)
31 #define ioremap_wc(phy, sz)		ioremap(phy, sz)
32 #define ioremap_wt(phy, sz)		ioremap(phy, sz)
33 
34 /* Change struct page to physical address */
35 #define page_to_phys(page)		(page_to_pfn(page) << PAGE_SHIFT)
36 
37 #define __raw_readb __raw_readb
38 static inline u8 __raw_readb(const volatile void __iomem *addr)
39 {
40 	u8 b;
41 
42 	__asm__ __volatile__(
43 	"	ldb%U1 %0, %1	\n"
44 	: "=r" (b)
45 	: "m" (*(volatile u8 __force *)addr)
46 	: "memory");
47 
48 	return b;
49 }
50 
51 #define __raw_readw __raw_readw
52 static inline u16 __raw_readw(const volatile void __iomem *addr)
53 {
54 	u16 s;
55 
56 	__asm__ __volatile__(
57 	"	ldw%U1 %0, %1	\n"
58 	: "=r" (s)
59 	: "m" (*(volatile u16 __force *)addr)
60 	: "memory");
61 
62 	return s;
63 }
64 
65 #define __raw_readl __raw_readl
66 static inline u32 __raw_readl(const volatile void __iomem *addr)
67 {
68 	u32 w;
69 
70 	__asm__ __volatile__(
71 	"	ld%U1 %0, %1	\n"
72 	: "=r" (w)
73 	: "m" (*(volatile u32 __force *)addr)
74 	: "memory");
75 
76 	return w;
77 }
78 
79 #define __raw_writeb __raw_writeb
80 static inline void __raw_writeb(u8 b, volatile void __iomem *addr)
81 {
82 	__asm__ __volatile__(
83 	"	stb%U1 %0, %1	\n"
84 	:
85 	: "r" (b), "m" (*(volatile u8 __force *)addr)
86 	: "memory");
87 }
88 
89 #define __raw_writew __raw_writew
90 static inline void __raw_writew(u16 s, volatile void __iomem *addr)
91 {
92 	__asm__ __volatile__(
93 	"	stw%U1 %0, %1	\n"
94 	:
95 	: "r" (s), "m" (*(volatile u16 __force *)addr)
96 	: "memory");
97 
98 }
99 
100 #define __raw_writel __raw_writel
101 static inline void __raw_writel(u32 w, volatile void __iomem *addr)
102 {
103 	__asm__ __volatile__(
104 	"	st%U1 %0, %1	\n"
105 	:
106 	: "r" (w), "m" (*(volatile u32 __force *)addr)
107 	: "memory");
108 
109 }
110 
111 #ifdef CONFIG_ISA_ARCV2
112 #include <asm/barrier.h>
113 #define __iormb()		rmb()
114 #define __iowmb()		wmb()
115 #else
116 #define __iormb()		do { } while (0)
117 #define __iowmb()		do { } while (0)
118 #endif
119 
120 /*
121  * MMIO can also get buffered/optimized in micro-arch, so barriers needed
122  * Based on ARM model for the typical use case
123  *
124  *	<ST [DMA buffer]>
125  *	<writel MMIO "go" reg>
126  *  or:
127  *	<readl MMIO "status" reg>
128  *	<LD [DMA buffer]>
129  *
130  * http://lkml.kernel.org/r/20150622133656.GG1583@arm.com
131  */
132 #define readb(c)		({ u8  __v = readb_relaxed(c); __iormb(); __v; })
133 #define readw(c)		({ u16 __v = readw_relaxed(c); __iormb(); __v; })
134 #define readl(c)		({ u32 __v = readl_relaxed(c); __iormb(); __v; })
135 
136 #define writeb(v,c)		({ __iowmb(); writeb_relaxed(v,c); })
137 #define writew(v,c)		({ __iowmb(); writew_relaxed(v,c); })
138 #define writel(v,c)		({ __iowmb(); writel_relaxed(v,c); })
139 
140 /*
141  * Relaxed API for drivers which can handle barrier ordering themselves
142  *
143  * Also these are defined to perform little endian accesses.
144  * To provide the typical device register semantics of fixed endian,
145  * swap the byte order for Big Endian
146  *
147  * http://lkml.kernel.org/r/201603100845.30602.arnd@arndb.de
148  */
149 #define readb_relaxed(c)	__raw_readb(c)
150 #define readw_relaxed(c) ({ u16 __r = le16_to_cpu((__force __le16) \
151 					__raw_readw(c)); __r; })
152 #define readl_relaxed(c) ({ u32 __r = le32_to_cpu((__force __le32) \
153 					__raw_readl(c)); __r; })
154 
155 #define writeb_relaxed(v,c)	__raw_writeb(v,c)
156 #define writew_relaxed(v,c)	__raw_writew((__force u16) cpu_to_le16(v),c)
157 #define writel_relaxed(v,c)	__raw_writel((__force u32) cpu_to_le32(v),c)
158 
159 #include <asm-generic/io.h>
160 
161 #endif /* _ASM_ARC_IO_H */
162